JP7621079B2 - Actuator units and safety switches - Google Patents

Description

The present invention relates to an actuator unit and a safety switch equipped with the same.

At the entrances and exits of dangerous areas where industrial machinery such as machine tools and industrial robots are installed, there are safety switches that turn on and off depending on whether the door is open or closed.

Generally, a safety switch is equipped with an actuator that is placed on the door side, and a switch body that is placed on the wall side, has an actuator insertion hole, and the contacts are switched in response to the movement of an internal operating rod. When the door is closed, the actuator on the door side is inserted into the actuator insertion hole of the switch body on the wall side, and the operating rod inside the switch body moves to switch the contacts.

In such safety switches, the actuator may become misaligned with respect to the actuator insertion hole due to door rattling or misalignment of the door itself, which may result in the actuator being unable to be smoothly inserted into the actuator insertion hole when the door is closed. Therefore, various measures have been taken to prevent such situations from occurring.

For example, in the actuator described in JP 2017-91877 A, the operation key (2) is supported on the base (3) so as to be able to swing, and the operation key (2) is returned to its reference position by the biasing force of the torsion coil spring (41). Therefore, even if the door rattles significantly, the operation key (2) swings when inserted, so that the operation key (2) is inserted into the key insertion port (103, 104) of the switch body (see paragraphs [0037], [0038], [0044], Fig. 1, Fig. 13 to Fig. 15 of the same publication).

In the key switch described in JP 8-138500 A, the key body (9) of the operation key (3) is slidably mounted on the support shaft (12) of the holder (8), and the key body (9) is arranged in a neutral sliding position by the biasing force of the elastic body (13). Therefore, even if an assembly error or misalignment occurs in the operation key (3) and the switch body (2), the operation key (3) slides when inserted, so that the operation key (3) is inserted into the key hole (6) of the switch body (2) (see paragraphs [0009] and [0020] and Figures 1 to 3 of the same publication).

In the driver for a safety switch described in JP 11-317132 A, the base (3) of the key (2) is attached to the holder (1) via a circular PTFE slide bearing (or roller bearing) (9) so that it can slide, and the key (2) is biased to a central position by a spring (10). By displacing the base (3) of the key (2) along the mounting surface of the slide bearing (9), misalignment between the driver and the insertion slot of the safety switch is corrected (see claim 1, paragraphs [0011] and [0012], and figures 1, 3, and 4 of the same publication).

In the device described in JP 2017-91877 A, when there is a positional deviation between the operation key (2) and the key insertion port (103, 104) of the switch body (100), the operation key (2) is adapted to swing when inserted into the key insertion port (103, 104) to absorb the positional deviation. This allows for a positional deviation in the swing direction of the operation key (2) (i.e., within the swing plane), but does not allow for a positional deviation in a direction intersecting (for example, perpendicular to) the swing direction.

In the device described in JP 8-138500 A, when there is a misalignment between the key body (9) of the operation key (3) and the key hole (6) of the switch body (2), the key body (9) slides when inserted into the key hole (6) to absorb the misalignment. This allows for a misalignment in the sliding direction of the key body (9) (i.e., within the sliding plane), but does not allow for a misalignment in a direction intersecting (for example, perpendicular to) the sliding direction.

In contrast, in the device described in JP 11-317132 A, when there is a misalignment between the key (2) and the insertion slot of the safety switch, the key (2) moves along the mounting surface of the slide bearing (9) when inserted into the insertion slot, absorbing the misalignment, and therefore can accommodate misalignments in any direction.

However, when the door is closed with a misalignment between the key (2) and the safety switch insertion slot, an excessive impact load due to the inertia of the door acts on the base (3) of the key (2), which acts directly on the PTFE slide bearing, causing the PTFE slide bearing to break and resulting in durability problems. JP 11-317132 A describes that a roller bearing may be used instead of the PTFE slide bearing, but when a roller bearing is used, the base (3) of the key (2) can only be displaced in the rolling direction of the roller bearing, so while it can accommodate misalignment in the rolling direction, it cannot accommodate misalignment in a direction intersecting (for example perpendicular) the rolling direction.

The present invention was made in consideration of the above-mentioned conventional situation, and the problem that the present invention aims to solve is to provide an actuator unit that can not only absorb positional deviations with respect to the actuator insertion hole in any direction intersecting with the insertion direction, but also improve durability.

The actuator unit of the present invention comprises an actuator having a tip portion that can be inserted into an actuator insertion hole, and a base portion that supports the base end portion of the actuator via a ball bearing so that it can move freely in any direction intersecting the insertion direction of the actuator into the actuator insertion hole, and any positional deviation between the tip end of the actuator and the actuator insertion hole is absorbed in any direction by movement of the base end portion of the actuator via the ball bearing.

According to the present invention, the base end of the actuator is supported on the base portion via the ball bearing so as to be freely movable in any direction intersecting with the insertion direction of the actuator, and the positional deviation between the tip end of the actuator and the actuator insertion hole is absorbed by the movement of the base end of the actuator via the ball bearing, so that the positional deviation with respect to the actuator insertion hole can be absorbed in any direction intersecting with the insertion direction. Moreover, according to the present invention, since the base end of the actuator is supported via the ball bearing, even if an excessive thrust load acts on the base end of the actuator due to an excessive load acting on the tip end of the actuator when the actuator is misaligned with the actuator insertion hole, the base end of the actuator can be reliably supported by the ball bearing, thereby improving the durability of the actuator unit. In addition, since rolling friction is much smaller than sliding friction, the use of ball bearings can reduce the friction coefficient compared to the use of slide bearings, thereby realizing smooth movement of the actuator and further improving durability.

In the present invention, the base end of the actuator has a holding portion that rotatably holds multiple balls, and each ball and the holding portion constitutes a ball bearing.

In the present invention, the tip of the actuator has a convex arc surface or an inclined surface. In this case, when the tip comes into contact with the opening edge of the actuator insertion hole due to misalignment, the base end of the actuator can move smoothly.

In the present invention, a first elastic support member that elastically supports the actuator from its outer periphery is provided on the base portion. In this case, the actuator can be returned to its original position after movement by the biasing force of the first elastic support member.

In the present invention, the actuator has a shaft portion extending between the tip end and the base end, and the base portion has an opening through which the shaft portion passes to allow movement of the base end.

In the present invention, a step is formed between the shaft and the tip.

In the present invention, a first elastic support member that elastically supports the shaft of the actuator from its outer periphery is provided on the base. In this case, the actuator can be returned to its original position after movement by the biasing force of the first elastic support member.

In the present invention, the first elastic support member covers the opening in the base portion.

In the present invention, the actuator has a locking hole that is engaged with a locking member inside the switch body that has an actuator insertion hole.

In the present invention, a second elastic support member is provided on the base portion to elastically support the base end of the actuator in the direction of insertion of the actuator. In this case, the thrust load acting on the actuator when the actuator is inserted in the event of misalignment can be borne by the second elastic support member, improving the durability of the ball bearing.

In the present invention, an arc-shaped plate member having a concave arc-shaped surface that constitutes the rolling surface of the ball bearing is provided on the base portion, and the arc-shaped plate member is elastically supported by a second elastic support member. In this case, since the rolling surface of the ball bearing is formed by the concave arc-shaped surface of the arc-shaped plate member, the base end of the actuator can be easily returned to its original position.

The safety switch according to the present invention comprises the actuator unit described in claim 1 and a switch body having an actuator insertion hole.

As described above, according to the present invention, misalignment between the tip of the actuator and the actuator insertion hole can be absorbed in any direction intersecting with the insertion direction of the actuator. Moreover, according to the present invention, even if an excessive thrust load acts on the actuator due to an excessive load acting on the tip of the actuator when misalignment occurs, the base end of the actuator can be reliably supported by the ball bearing, thereby improving the durability of the actuator unit.

1 is a diagram showing a schematic configuration of a safety switch including an actuator unit and a switch main body according to an embodiment of the present invention; FIG. 2 is an overall perspective view of the actuator unit ( FIG. 1 ). FIG. 3 is a plan view of the actuator unit (FIG. 2). 4 is a bottom view taken along line IV-IV in FIG. 1 with a bottom cover removed from the actuator unit (FIG. 2). FIG. 5 is a cross-sectional view taken along line V-V in FIG. 4, showing a vertical cross section of the actuator unit (FIG. 2). 6 is a cross-sectional view taken along line VI-VI in FIG. 5, showing a cross section of the base portion of the actuator unit (FIG. 2). FIG. 2 is a diagram showing the safety switch (FIG. 1) in a state where the actuator is inserted inside the switch body; 5A to 5C are diagrams showing, in the safety switch (FIG. 1), movements of the actuator unit and the actuator in a time series manner in the case where the actuator unit is misaligned with respect to an actuator insertion hole of the switch body. 5A to 5C are diagrams showing, in the safety switch (FIG. 1), movements of the actuator unit and the actuator in a time series manner in the case where the actuator unit is misaligned with respect to an actuator insertion hole of the switch body. 5A to 5C are diagrams showing, in the safety switch (FIG. 1), movements of the actuator unit and the actuator in a time series manner in the case where the actuator unit is misaligned with respect to an actuator insertion hole of the switch body. FIG. 11 is a plan view of the actuator unit (FIG. 10) and corresponds to FIG. 3. 12 is a bottom view taken along line XII-XII in FIG. 10 with a bottom cover removed from the actuator unit (FIG. 10). FIG. 13 is a vertical cross-sectional view taken along line XIII-XIII in FIG. 12, showing a vertical cross-section of the actuator unit (FIG. 10). 14 is a cross-sectional view taken along line XIV-XIV in FIG. 13, showing a cross section of the base portion of the actuator unit (FIG. 10). FIG. 9 is a diagram showing a state in which the actuator (FIG. 8) is inserted into the switch body; FIG. 16 is a cross-sectional view taken along line XVI-XVI of an actuator unit (FIG. 18) according to a first modified example of the present invention, and corresponds to FIG. 6 of the above embodiment. FIG. 19 is a bottom view of the actuator unit (FIG. 18) and corresponds to FIG. 4 of the embodiment. 18 is a cross-sectional view taken along line XVIII-XVIII of FIG. 17. 18 shows a state after the actuator has moved when the actuator unit (FIG. 18) is misaligned with respect to the actuator insertion hole of the switch body, and corresponds to FIG. 14 of the previous embodiment. FIG. 22 is a cross-sectional view of an actuator unit according to a second modified example of the present invention taken along line XX-XX, and corresponds to FIG. 6 of the above embodiment. FIG. 23 is a bottom view of the actuator unit (FIG. 22) and corresponds to FIG. 4 of the embodiment. This is a cross-sectional view taken along line XXII-XXII in Figure 21. 22 shows a state after the actuator has moved when the actuator unit (FIG. 22) is misaligned with respect to the actuator insertion hole of the switch body, and corresponds to FIG. 14 of the previous embodiment. FIG. 27 is a cross-sectional view of an actuator unit according to a third modified example of the present invention (FIG. 26), taken along line XXIV-XXIV, and corresponds to FIG. 6 of the above-described embodiment. FIG. 27 is a bottom view of the actuator unit (FIG. 26) and corresponds to FIG. 4 of the embodiment. 26 is a cross-sectional view taken along line XXVI-XXVI of FIG. 25. 26 shows a state after the actuator has moved when the actuator unit (FIG. 26) is misaligned with respect to the actuator insertion hole of the switch body, and corresponds to FIG. 14 of the previous embodiment. FIG. 30 is a cross-sectional view of an actuator unit according to a fourth modified example of the present invention taken along line XXVIII-XXVIII, and corresponds to FIG. 6 of the above-described embodiment. FIG. 31 is a bottom view of the actuator unit (FIG. 30) and corresponds to FIG. 4 of the embodiment. This is a cross-sectional view taken along line XXX-XXX in Figure 29. 30 shows a state after the actuator has moved when the actuator unit (FIG. 30) is misaligned with respect to the actuator insertion hole of the switch body, and corresponds to FIG. 14 of the previous embodiment. FIG. 32 is a cross-sectional view taken along line XXXII-XXXII of an actuator unit according to a fifth modified example of the present invention (FIG. 34), which corresponds to FIG. 6 of the above-described embodiment. FIG. 35 is a bottom view of the actuator unit (FIG. 34) and corresponds to FIG. 4 of the embodiment. This is a cross-sectional view of line XXXIV-XXXIV in Figure 33. 34 is a view showing a state after the actuator has moved when the actuator unit (FIG. 34) is misaligned with respect to the actuator insertion hole of the switch body, and corresponds to FIG. 14 of the previous embodiment. FIG. 13 is an overall perspective view of an actuator unit according to a sixth modified example of the present invention, which corresponds to FIG. 2 of the above embodiment. FIG. 37 is a vertical cross-sectional view of the actuator unit (FIG. 36) with the bottom cover removed, and corresponds to FIG. 5 of the embodiment. FIG. 37 is a bottom view of the actuator unit (FIG. 36) with the bottom cover removed, and corresponds to FIG. 4 of the embodiment. 36 is a view showing a state after the actuator has moved when the actuator unit is misaligned with respect to the actuator insertion hole of the switch body, and corresponds to FIG. 13 of the previous embodiment. FIG. 13 is a schematic vertical sectional view of an actuator unit according to a seventh modified example of the present invention. 40 shows a state after the actuator has moved when the actuator unit (FIG. 40) is misaligned with respect to the actuator insertion hole of the switch body, and corresponds to FIG. 13 of the previous embodiment. FIG. 13 is a schematic vertical sectional view of an actuator unit according to an eighth modified example of the present invention. 42 is a view showing a state after the actuator has moved when the actuator unit (FIG. 42) is misaligned with respect to the actuator insertion hole of the switch body, and corresponds to FIG. 13 of the previous embodiment. FIG. 13 is a schematic vertical cross-sectional view of an actuator unit according to a ninth modified example of the present invention. 44 shows a state after the actuator has moved when the actuator unit (FIG. 44) is misaligned with respect to the actuator insertion hole of the switch body, and corresponds to FIG. 13 of the previous embodiment. FIG. 23 is a diagram showing a schematic configuration of a safety switch including an actuator unit and a switch main body according to a tenth modified example of the present invention. FIG. 47 is a vertical cross-sectional view of the actuator unit (FIG. 46) with the bottom cover removed, and corresponds to FIG. 5 of the above embodiment. 47A to 47C are views showing, in the safety switch (FIG. 46), movements of the actuator unit and the actuator in a time series manner in the case where the actuator unit is misaligned with respect to the actuator insertion hole of the switch body. 47A to 47C are views showing, in the safety switch (FIG. 46), movements of the actuator unit and the actuator in a time series manner in the case where the actuator unit is misaligned with respect to the actuator insertion hole of the switch body. 47A to 47C are views showing, in the safety switch (FIG. 46), movements of the actuator unit and the actuator in a time series manner in the case where the actuator unit is misaligned with respect to the actuator insertion hole of the switch body. 47 shows a state after the actuator has moved when the actuator unit (FIG. 47) is misaligned with respect to the actuator insertion hole of the switch body, and corresponds to FIG. 13 of the previous embodiment. FIG. 51 is a schematic view taken along the line LII in FIG. 50, and corresponds to FIG. 7 in the embodiment. FIG. 19 is a bottom view of an actuator unit according to an eleventh modified example of the present invention with the bottom cover removed, showing a modified example of the base end portion in FIG. 4 of the above embodiment. FIG. 23 shows an actuator unit according to a twelfth modified example of the present invention, and corresponds to FIG. 6 of the above embodiment. FIG. 23 shows an actuator unit according to a thirteenth modified example of the present invention, and corresponds to FIG. 16 showing the first modified example. FIG. 32 shows an actuator unit according to a fourteenth modified example of the present invention, which corresponds to FIG. 32 showing the fifth modified example.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.
1 to 15 are diagrams for explaining an actuator unit according to one embodiment of the present invention and a safety switch equipped with the same, in which FIG. 1 is a schematic diagram of the safety switch, FIG. 2 is an overall perspective view of the actuator unit, FIG. 3 is a plan view thereof, FIG. 4 is a bottom view (view taken along line IV-IV in FIG. 1) with the bottom cover removed from the actuator unit, FIG. 5 is a vertical sectional view (view taken along line VV in FIG. 4) with the bottom cover removed from the actuator unit, FIG. 6 is a sectional view taken along line VI-VI in FIG. 5, and FIG. 7 is a diagram showing a state in which the actuator has been inserted into the switch body from the state shown in FIG. 1. 8 to 10 are diagrams showing the state in which the actuator unit and the actuator are inserted into the switch body when the actuator unit is misaligned with respect to the actuator insertion hole of the switch body; FIG. 11 is a plan view after the actuator has been moved; FIG. 12 is a bottom view after the actuator has been moved (view taken along line XII-XII in FIG. 10); FIG. 13 is a longitudinal cross-sectional view after the actuator has been moved (cross-sectional view along line XIII-XIII in FIG. 12); FIG. 14 is a cross-sectional view along line XIV-XIV in FIG. 13; and FIG. 15 is a diagram showing the state in which the actuator has been inserted into the switch body from the state shown in FIG. 8.

As shown in Figure 1, the safety switch 1 of this embodiment comprises a switch body 2 that is placed, for example, on a wall or a fixed door (not shown), and an actuator unit 3 that is placed, for example, on a sliding movable door (not shown) and is provided so as to be insertable and removable from the switch body 2. Figure 1 shows the movable door as viewed from the front, and in the figure, arrow A indicates the insertion direction of the actuator unit 3. Note that Figure 1 shows the movable door in the middle of closing, with the movable door slightly open.

The switch body 2 has one or a plurality of actuator insertion holes 20. The actuator insertion hole 20 is, for example, a circular tapered hole penetrating the wall of the switch body 2, and has a tapered surface 20a that gradually decreases in diameter from the outer surface of the wall of the switch body 2 toward the inside of the switch body 2. In Fig. 1, a dashed line 2C _L indicates the center line of the actuator insertion hole 20. Although not shown, a switchable contact is provided inside the switch body 2, and a locking member (described later) that locks the inserted actuator unit 3 is also provided.

The actuator unit 3 has an actuator 3A having a tip portion 30 that can be inserted into the actuator insertion hole 20 of the switch body 2, and a base portion 3B that accommodates the base end side of the actuator 3A. The tip portion 30 is, for example, a semispherical protrusion, and has a convex arcuate surface 30a arranged on the tip side and a flat surface 30b arranged on the rear end side, and the tip of a shaft portion 31, for example, a cylindrical shape extending in the axial direction, is integrally connected to the flat surface 30b. The shaft portion 31 is a member having a smaller diameter than the tip portion 30, and the flat surface 30b forms a step with respect to the tip of the shaft portion 31. In FIG. 1, a dashed line 3C _L indicates the center line of the shaft portion 31 (i.e., the actuator 3A) in the axial direction, and in this example, the state in which the center line 3C _L coincides with the center line 2C _L of the actuator insertion hole 20 of the switch body 2 is shown.

2 and 3, the base 3B is, for example, a box-shaped member, and includes a box-shaped base body 32 having, at one end, for example, a circular opening 32a through which the shaft 31 of the actuator 3A passes and an open end, and a thin plate-like lid 33 that covers the opening at the other end of the base body 32. The inner diameter of the opening 32a is, for example, several millimeters to tens of millimeters larger than the outer diameter of the shaft 31 so as to allow the shaft 31 to move within the opening 32a. The base body 32 also has a number of screw insertion holes 32b into which mounting screws (not shown) for the lid 33 and mounting screws (not shown) for mounting the actuator unit 3 to a movable door are inserted.

4 and 5, the base end 34 of the actuator 3A is accommodated inside the base portion 3B. The base end 34 is a disk-shaped member arranged at the rear end of the shaft portion 31 and has a larger diameter than the shaft portion 31, and is integrally connected to the rear end of the shaft portion 31. That is, the shaft portion 31 extends between the tip portion 30 and the base end 34 of the actuator 3A. A plurality of (five in this example) circular retaining holes 34a are formed on the rear end surface of the base end 34. The retaining holes 34a are arranged at equal or approximately equal intervals on the circumference. Each retaining hole 34a accommodates, for example, a steel ball (i.e., a steel ball) 35, and each ball 35 is supported in each retaining hole 34a so as to be rotatable (i.e., freely rotating). Each retaining hole 34a is filled with, for example, grease as a lubricant. The bottom of each retaining hole 34a is formed, for example, in a tapered shape, and the depth of each retaining hole 34a is set so that a part of each housed ball 35 peeks out (i.e., protrudes) from the open end of each retaining hole 34a (i.e., the rear end surface of the base end 34) (see FIG. 5). Each retaining hole 34a and each ball 35 constitutes a ball bearing. In this case, the base end 34 itself constitutes the holder (i.e., the retainer) for the ball bearing.

4 and 5 show the state in which the lid 33 (FIG. 1) is removed from the base 3B. When the lid 33 is attached, as shown by the dashed line in FIG. 5, each ball 35 protruding from the rear end surface of the base end 34 abuts against the inner surface of the lid 33 and is free to move along the inner surface in the direction of arrow B. Here, the direction of arrow B refers to any direction perpendicular or nearly perpendicular (i.e. intersecting) to the direction of arrow A, which is the insertion direction of the actuator unit 3. In other words, the direction of arrow B includes not only the direction within the plane of FIG. 5, but also all directions that form an angle to the front and back of the plane of the figure. To explain this using FIG. 4, the base end 34 can move in any direction within the plane of the figure, including vertical, horizontal, and diagonal directions. As described above, the opening 32a formed on one end of the base portion 3B is formed larger than the shaft portion 31 so as to allow the shaft portion 31 to move within the opening 32a (FIGS. 2 and 3), allowing the base end portion 34 (and therefore the actuator 3A) to move relative to the base portion 3B.

As shown in Fig. 5, the shaft portion 31 of the actuator 3A has a flange portion 31f that protrudes outward from the base portion 3B. The flange portion 31f is, for example, a disk-shaped member. The flange portion 31f is disposed at a predetermined interval from the base end portion 34. Between the flange portion 31f and the base end portion 34, a plurality of wires (first elastic support members) ₃₇₁ , 372, ₃₇₃ , 374 (four in this example) are disposed, which extend in a direction perpendicular or substantially perpendicular (i.e., intersecting) with the direction of the arrow A (see Fig. 4). Each of the wires ₃₇₁ , ₃₇₂ , ₃₇₃ , ₃₇₄ is made of, for example, a high _- tensile steel wire such as a piano wire, or other steel wire, metal wire, or _the like.

As shown in Fig. 6, the wires 37 ₁ and 37 ₂ are arranged in parallel in the vertical direction so as to sandwich the shaft portion 31 from both the left and right sides of the figure, and the wires 37 ₃ and 37 ₄ are arranged in parallel in the horizontal direction so as to sandwich the shaft portion 31 from both the top and bottom sides of the figure. That is, the wires 37 ₁ , 37 ₂ , 37 ₃ , and 37 ₄ are arranged in a lattice shape. The wires 37 ₁ and 37 ₂ are arranged on the front side of the paper surface of Fig. 6 with respect to the wires 37 ₃ and 37 _4. The base body 32 of the base portion 3B is provided with a plurality of (eight in this example) support columns 36 each extending in a direction perpendicular to the paper surface of Fig. 6. Each of the wires 37 ₁ to 37 ₄ is sandwiched between two support columns 36 and the shaft portion 31, and elastically abuts against the outer circumferential surface of the shaft portion 31. As a result, the shaft portion 31 (and therefore the actuator 3A) is elastically supported from the outer periphery by the wires 37 ₁ to 37 ₄ .

As shown in FIG. 5, a washer 38 is disposed between the flange portion 31f of the shaft portion 31 of the actuator 3A and the front wall portion of the base body 32 of the base portion 3B. The washer 38 is a thin-walled circular (donut-shaped) member, and has an opening 38a through which the shaft portion 31 of the actuator 3A is inserted. The inner diameter of the opening 38a is larger than the outer diameter of the shaft portion 31 and smaller than the opening 32a of the base body 32. The outer diameter of the washer 38 is also larger than the opening 32a.

Next, the effects of this embodiment will be described.
When the movable door is moved in the closing direction from the state shown in FIG. 1, the actuator 3A of the actuator unit 3 moves in the direction of the arrow A, and as shown in FIG. 7, the actuator 3A is inserted into the switch body 2 through the actuator insertion hole 20 of the switch body 2. As described above, during this insertion, the center line 3C _L of the actuator 3A coincides with the center line 2C _L of the actuator insertion hole 20 of the switch body 2, so that the tip 30 of the actuator 3A is smoothly inserted into the switch body 2 without interfering with the tapered surface 20a of the actuator insertion hole 20. Then, the locking member SR inside the switch body 2 locks the flat surface 30b that forms the step between the tip 30 and the shaft 31 of the actuator 3A. This locks the actuator 3A and prevents it from coming off. From this state, the contacts (not shown) inside the switch body 2 are switched, and the operation of a machine such as a robot is started.

8, assume that the center line _3CL of the shaft portion 31 (i.e., the actuator 3A) is misaligned with the center line _2CL of the actuator insertion hole 20 of the switch body 2, and the distance of the misalignment (i.e., the offset amount) is e. In the figure, an example is shown in which the center line _3CL is misaligned upward by a distance e with respect to the center line _2CL .

When the movable door is moved in the closing direction from this state, the actuator 3A of the actuator unit 3 moves in the direction of arrow A, and as shown in FIG. 9, the tip 30 of the actuator 3A comes into contact with the tapered surface 20a of the actuator insertion hole 20 of the switch body 2. At this time, the convex arc-shaped surface 30a of the tip 30 comes into contact with the tapered surface 20a, so that while the movable door is closed, the convex arc-shaped surface 30a of the tip 30 slides along the tapered surface 20a and attempts to move diagonally downward as shown in the figure.

5, the balls 35 protruding from the rear end surface of the base end 34 of the actuator 3A are movable in the direction of arrow B along the inner surface of the lid 33. When a force acts on the tip end 30 of the actuator 3A to move it downward while the movable door is closed, the balls 35 roll on the inner surface of the lid 33, causing the base end 34 to move downward along the inner surface of the lid 33 (see FIG. 13). As described above, the opening 32a formed on one end of the base 3B is formed larger than the shaft 31 so as to allow the shaft 31 to move within the opening 32a (see FIGS. 2 and 3), so the movement of the base end 34 (and therefore the actuator 3A) relative to the base 3B is smooth.

As a result, the tip 30 of the actuator 3A moves diagonally downward in FIG. 9 along the tapered surface 20a of the actuator insertion hole 20, and as shown in FIG. 10, the tip 30 is inserted into the actuator insertion hole 20. When the movable door moves further in the closing direction from this state, the tip 30 of the actuator 3A passes through the actuator insertion hole 20 of the switch body 2 and is inserted into the inside of the switch body 2. Then, as shown in FIG. 15, the locking member SR inside the switch body 2 locks the flat surface 30b that forms the step between the tip 30 of the actuator 3A and the shaft portion 31. This locks the actuator 3A and prevents it from coming loose. From this state, the contacts (not shown) inside the switch body 2 switch, and the operation of a machine such as a robot begins.

In this way, according to this embodiment, if the tip end 30 of the actuator 3A is misaligned with respect to the actuator insertion hole 20 of the switch body 2, the misalignment is absorbed by the movement of the base end 34 of the actuator 3A via the ball bearing, and this makes it possible to absorb the misalignment of the actuator 3A with respect to the actuator insertion hole 20 in any direction (arrow B direction) that intersects with the actuator insertion direction (arrow A direction).

Moreover, according to this embodiment, since the base end 34 of the actuator 3A is supported via a ball bearing, even if an excessive thrust load acts on the base end 34 of the actuator 3A due to an excessive load acting on the tip end 30 of the actuator 3A when the actuator is misaligned with the actuator insertion hole 20, the base end 34 of the actuator 3A can be reliably supported by the ball bearing, thereby improving the durability of the actuator unit 3. In addition, since rolling friction is much smaller than sliding friction, the use of a ball bearing makes it possible to reduce the coefficient of friction compared to the use of a sliding bearing, thereby realizing smoother movement of the actuator 3A and further improving durability.

When the base end 34 of the actuator 3A moves downward, as shown in FIG. 13, the washer 38 also moves downward slightly in conjunction with the downward movement of the shaft portion 31. However, even in this case, the upper area of the flange portion 31f within the opening 32a of the base body 32 is blocked by the washer 38, so that the inside of the base portion 3B is not exposed to the outside through the opening 32a.

When the tip 30 of the actuator 3A is inserted into the switch body 2, the tip 30 and the base 34 each move downward (see Figs. 11 and 12), and at this time, as shown in Fig. 14, the shaft 31 of the actuator 3A also moves downward, abutting against the lower wire _{374 and elastically deforming it downward. Therefore, at this time, an elastic repulsive force caused by the elastic deformation of the wire 374 acts} upward on the outer circumferential surface of the shaft 31.

Therefore, when the movable door is opened and the tip portion 30 of the actuator 3A tries to leave the actuator insertion hole 20 of the switch body 2 as the movable door moves, the shaft portion 31 (and therefore the actuator 3A) tries to move upward due to the elastic repulsive force of the wire ₃₇₄ acting on the shaft portion 31. At this time, the base end portion 34 of the actuator 3A is movable by the ball bearing, so that the upward movement of the actuator 3A is performed smoothly.

In the above embodiment, an example has been described in which, due to an upward positional deviation of the actuator 3A with respect to the actuator insertion hole 20, the shaft portion 31 of the actuator 3A comes into contact with the lower wire _37-4 and elastically deforms the wire _37-4 downward when the positional deviation is absorbed. In the case of a downward positional deviation, the shaft portion 31 comes into contact with the upper wire _37-3 and elastically deforms it upward, and in the case of a left/right positional deviation, the shaft portion 31 comes into contact with the left/right wire _37-1 or _37-2 and elastically deforms the wire _37-1 or _37-2 to the left or right in FIG. 6 .

[First Modification]
16 to 19 show a first modified example of the present invention (particularly a modified example of the first elastic support member), and in each figure, the same reference numerals as in the above embodiment indicate the same or corresponding parts. In the above embodiment, four wires each extending linearly are used, and the wires ₃₇₁ , ₃₇₂ , ₃₇₃ , ₃₇₄ are arranged in a lattice pattern in the vertical and horizontal directions (see Figs. 4 and 6), but in this first modified example, four torsion coil springs _37C1 , _37C2 , _37C3 , _37C4 are used as the first elastic support member.

As shown in Fig. 16, the coil portion of the torsion coil spring _37C1 is attached to the support ₃₆₁ of the base body 32, the fixed arm ₃₇₁ ' is engaged with the inner wall surface of the base body 32, and the movable arm ₃₇₁ is in elastic contact with the outer circumferential surface of the shaft portion 31 (see Fig. 16). Similarly, the coil portion of the torsion coil spring _37C2 is attached to the support ₃₆₂ , the fixed arm ₃₇₂ ' is engaged with the inner wall surface of the base body 32, and the movable arm ₃₇₂ is in elastic contact with the outer circumferential surface of the shaft portion 31. The coil portion of the torsion coil spring _37C3 is attached to the support ₃₆₃ , the fixed arm ₃₇₃ ' is engaged with the inner wall surface of the base body 32, and the movable arm ₃₇₃ is in elastic contact with the outer circumferential surface of the shaft portion 31. The coil portion of the torsion coil spring _37C4 is attached to the support ₃₆₄ , the fixed arm portion ₃₇₄ ' is engaged with the inner wall surface of the base body 32, and the movable arm portion ₃₇₄ is in elastic contact with the outer circumferential surface of the shaft portion 31.

As a result, the movable arms ₃₇₁ , ₃₇₂ , ₃₇₃ , ₃₇₄ of each torsion coil spring _37C1 , _37C2 , _37C3 , _37C4 are arranged in a lattice pattern in diagonal directions and diagonal directions perpendicular or nearly perpendicular to the diagonal directions, and the shaft portion 31 (and therefore the actuator 3A) is elastically supported from the outer periphery by the movable arms ₃₇₁ , ₃₇₂ , ₃₇₃ , ₃₇₄ of each torsion coil spring _37C1 , _37C2 , _37C3 , _37C4 .

As shown in FIG. 18, the movable arms 37 ₁ , 37 ₂ , 37 ₃ , and 37 ₄ of the torsion coil springs 37C ₁ , 37C ₂ , 37C ₃ , and 37C ₄ are disposed between the base end 34 of the actuator 3A and the flange portion 31f, similar to the wires 37 ₁ , 37 ₂ , 37 ₃ , and 37 ₄ of the above embodiment.

Even in this first modified example, if the tip 30 of the actuator 3A is misaligned with respect to the actuator insertion hole 20 of the switch body 2 (see FIG. 8 of the above embodiment), the misalignment is absorbed by the movement of the base end 34 of the actuator 3A via the ball bearing (see FIGS. 17 and 18). Not only can the misalignment of the actuator 3A with respect to the actuator insertion hole 20 be absorbed in any direction (arrow B direction) intersecting the actuator insertion direction (arrow A direction), but the base end 34 is supported via a ball bearing, so that the base end 34 can be reliably supported by the ball bearing when an excessive thrust load acts on the base end 34 when the actuator 3A is inserted.

Furthermore, when the tip 30 of the actuator 3A is inserted into the switch body 2 in a state where it is displaced upward (see FIG. 15 in the above embodiment), the tip 30 and the base end 34 move downward, causing the shaft 31 to move downward as well, and at this time, the shaft 31 comes into contact with the lower movable arms 37 ₂ , 37 ₃ , elastically deforming them downward (see FIG. 19). Therefore, at this time, an elastic repulsive force caused by the elastic deformation of the movable arms 37 ₂ , 37 ₃ acts upward on the outer circumferential surface of the shaft 31.

Therefore, when the movable door is opened and the tip portion 30 of the actuator 3A tries to leave the actuator insertion hole 20 of the switch body 2 as the movable door moves, the shaft portion 31 (and therefore the actuator 3A) tries to move upward due to the elastic repulsive force of each of the movable arms ₃₇₂ , ₃₇₃ acting on the shaft portion 31. At this time, the base end portion 34 of the actuator 3A is movable by the ball bearing, so the upward movement of the actuator 3A is performed smoothly.

In Figure 19, an example has been described in which, due to an upward positional deviation of actuator 3A relative to actuator insertion hole 20, the shaft portion 31 of actuator 3A abuts against the lower movable arms ₃₇₂ , ₃₇₃ when absorbing the positional deviation, causing each of the movable arms ₃₇₂ , ₃₇₃ to elastically deform downward. In the case of a downward positional deviation, the shaft portion 31 abuts against the upper movable arms ₃₇₁ , _374, causing each of the movable arms ₃₇₁ , ₃₇₄ to elastically deform upward, and in the case of a left/right positional deviation, the shaft portion 31 abuts against the left and right movable arms ₃₇₃ , ₃₇₄ or ₃₇₁ , _372, causing each of the movable arms ₃₇₃ , ₃₇₄ or ₃₇₁ , ₃₇₂ to elastically deform leftward or rightward in Figure 16.

[Second Modification]
20 to 23 show a second modified example of the present invention (particularly a modified example of the first elastic support member), and in each figure, the same reference numerals as those in the above embodiment or the first modified example indicate the same or corresponding parts. In the above embodiment, four wires each extending linearly are used, and the wires ₃₇₁ , ₃₇₂ , ₃₇₃ , ₃₇₄ are arranged in a lattice pattern in the vertical and horizontal directions (see Figs. 4 and 6), but in this second modified example, four tension coil springs _37C1 , _37C2 , _37C3 , _37C4 are used as the first elastic support member.

As shown in Fig. 20, the tension coil springs _37C1 and _37C3 are arranged in the vertical direction, and the tension coil springs _37C2 and _37C4 are arranged in the horizontal direction, and the tension coil springs _37C1 , _37C2 , _37C3 , and _37C4 are arranged in a cross shape on an extension line passing through the center O of the shaft portion ₃₁ of the actuator 3A. The hook portion at one end of the tension coil spring 37C1 is engaged with the support ₃₆₁ of the base body 32, and the hook portion at the other end is engaged with a locking protrusion 31fa protruding rearward (to the right in the figure) from the rear end surface of the flange portion 31f of the actuator 3A as shown in Fig. 22 (see Fig. 20). Similarly, the hook portion at one end of the tension coil spring _37C2 is engaged with the support ₃₆₂ of the base body 32, and the hook portion at the other end is engaged with the locking protrusion 31fa of the flange portion 31f. A hook portion at one _end of the tension coil spring 37C3 is engaged with the support ₃₆₃ of the base body 32, and a hook portion at the other end is engaged with the locking projection 31fa of the flange portion 31f. A hook portion at _one end of the tension coil spring 37C4 is engaged with the support ₃₆₄ of the base body 32, and a hook portion at the other end is engaged with the locking projection 31fa of the flange portion 31f.

As a result, the shaft portion 31 (and therefore the actuator 3A) is elastically supported from the outer periphery by the tension coil springs _37C1 , _37C2 , _37C3 , and 37C4. Also, as shown in Figure 22, the tension coil springs _37C1 , _{37C2 , 37C3} , and _37C4 are disposed between the base end portion ₃₄ of the actuator 3A and the flange portion 31f, similar to the wires ₃₇₁ , ₃₇₂ , 373, and ₃₇₄ of the above embodiment.

Even in this second modified example, if the tip 30 of the actuator 3A is misaligned with respect to the actuator insertion hole 20 of the switch body 2 (see FIG. 8 of the previous embodiment), the misalignment is absorbed by the movement of the base end 34 of the actuator 3A via the ball bearing (see FIGS. 21 and 22). Not only can the misalignment of the actuator 3A with respect to the actuator insertion hole 20 be absorbed in any direction (arrow B direction) intersecting the actuator insertion direction (arrow A direction), but the base end 34 is supported via a ball bearing, so that the base end 34 can be reliably supported by the ball bearing when an excessive thrust load acts on the base end 34 when the actuator 3A is inserted.

Furthermore, when the tip 30 of the actuator 3A is inserted into the switch body 2 in a state where it is displaced upward (see FIG. 15 in the above embodiment), the tip 30 and the base end 34 move downward, causing the shaft 31 to move downward as well, at which point the lower tension coil spring _37C3 is compressed and the upper and left and right tension coil springs _37C1 , _37C2 , _37C4 are tensilely deformed, as shown in FIG 23. At this time, an elastic repulsive force caused by the elastic deformation of the tension coil springs _37C1 , _37C2 , _37C3 , _37C4 acts upward on the outer periphery of the shaft 31.

Therefore, when the movable door is opened and the tip portion 30 of the actuator 3A attempts to leave the actuator insertion hole 20 of the switch body 2 as the movable door moves, the shaft portion 31 (and therefore the actuator 3A) attempts to move upward due to the elastic repulsive forces of the tension coil springs _37C1 , _37C2 , _37C3 , _37C4 acting on the shaft portion 31. At this time, the base end portion 34 of the actuator 3A is movable by the ball bearings, so the upward movement of the actuator 3A is smooth.

23 has been described as an example in which, due to an upward positional deviation of the actuator 3A with respect to the actuator insertion hole 20, when the positional deviation is absorbed, the lower tension coil spring _37C3 is compressed and the upper and left and right tension coil springs _37C1 , _37C2 , and _37C4 are tensilely deformed. In the case of a downward positional deviation, the upper tension coil spring _37C1 is compressed and the lower and left and right tension coil springs _37C2 , _37C3 , and _37C4 are tensilely deformed. In the case of a leftward positional deviation, the right tension coil spring _37C2 is compressed and the upper, lower and left tension coil springs _37C1 , _37C3 , and _37C4 are tensilely deformed. In the case of a rightward positional deviation, the left tension coil spring _37C4 is compressed and the upper, lower and right tension coil springs _37C1 , 37C2, and 37C4 are tensilely deformed. , _37C2 , and _37C3 are subjected to tensile deformation.

[Third Modification]
24 to 27 show a third modified example of the present invention (particularly a modified example of the first elastic support member), and in each figure, the same reference numerals as those in the above embodiment and the first or second modified example indicate the same or corresponding parts. In the above embodiment, four wires each extending linearly are used, and the wires ₃₇₁ , ₃₇₂ , ₃₇₃ , ₃₇₄ are arranged in a lattice pattern in the vertical and horizontal directions (see Figs. 4 and 6), but in this third modified example, a single spiral spring 37C is used as the first elastic support member.

As shown in FIG. 24, one end 37Ca on the inner periphery of the spiral spring 37C is engaged with a locking recess formed on the outer periphery of the shaft portion 31 of the actuator 3A, and the other end 37Cb on the outer periphery is engaged with a locking recess formed on the inner wall surface of the base body 32 of the base portion 3B.

As a result, the shaft portion 31 (and therefore the actuator 3A) is elastically supported from the outer periphery by the spiral spring 37C. As shown in Figure 26, the spiral spring 37C is disposed between the base end portion 34 of the actuator 3A and the flange portion 31f, similar to the wires ₃₇₁ , ₃₇₂ , ₃₇₃ , and ₃₇₄ of the above embodiment.

Even in this third modified example, if the tip 30 of the actuator 3A is misaligned with respect to the actuator insertion hole 20 of the switch body 2 (see FIG. 8 of the previous embodiment), the misalignment is absorbed by the movement of the base end 34 of the actuator 3A via the ball bearing (see FIGS. 25 and 26). Not only can the misalignment of the actuator 3A with respect to the actuator insertion hole 20 be absorbed in any direction (arrow B direction) intersecting the actuator insertion direction (arrow A direction), but the base end 34 is supported via a ball bearing, so that the base end 34 can be reliably supported by the ball bearing when an excessive thrust load acts on the base end 34 when the actuator 3A is inserted.

In addition, when the tip 30 of the actuator 3A is inserted into the switch body 2 while being displaced upward (see FIG. 15 in the above embodiment), the tip 30 and base end 34 move downward, causing the shaft 31 to move downward as well. At this time, an elastic repulsive force due to the elastic deformation of the spiral spring 37C acts upward on the outer circumferential surface of the shaft 31 (see FIG. 27).

Therefore, when the movable door is opened and the tip 30 of the actuator 3A tries to leave the actuator insertion hole 20 of the switch body 2 as the movable door moves, the elastic repulsive force of the spiral spring 37C acting on the shaft 31 causes the shaft 31 (and therefore the actuator 3A) to move upward. At this time, the base end 34 of the actuator 3A is movable by the ball bearing, so the actuator 3A moves upward smoothly.

27, the actuator 3A is displaced upward relative to the actuator insertion hole 20, and the shaft 31 of the actuator 3A elastically deforms the spiral spring 37C downward when absorbing the displacement. In the case of a downward displacement, the shaft 31 elastically deforms the spiral spring 37C upward, and in the case of a left-right displacement, the shaft 31 elastically deforms the spiral spring 37C leftward or rightward. In the third modified example, one end of the inner periphery of the spiral spring 37C is engaged with the shaft 31 of the actuator 3A, and the other end of the outer periphery is engaged with the base body 32. When the shaft 31 tries to rotate during the movement of the actuator 3A, the spiral spring 37C is twisted and its elastic restoring force acts on the shaft 31, so that the rotation of the shaft 31 can be restricted.

[Fourth Modification]
28 to 31 show a fourth modified example of the present invention (particularly a modified example of the first elastic support member), and in each figure, the same reference numerals as those in the above embodiment and the first to third modified examples indicate the same or corresponding parts. In the above embodiment, four wires each extending linearly are used, and the wires ₃₇₁ , ₃₇₂ , ₃₇₃ , ₃₇₄ are arranged in a lattice pattern in the vertical and horizontal directions (see Figs. 4 and 6), but in this fourth modified example, four tension coil springs _37C1 , _37C2 , _37C3 , _37C4 are used as the first elastic support member.

28, the tension coil springs _37C1 , _37C2 are arranged linearly in the left-right direction above the shaft portion 31 of the actuator 3A, and the tension coil springs _37C3 , _37C4 are arranged linearly in the left-right direction below the shaft portion 31, with the tension coil springs _37C1 , _37C2 arranged parallel to the tension coil springs _37C3 , _37C4 . A hook portion at one end of the tension coil spring _37C1 is engaged with the support _36-1 of the base main body 32, and a hook portion at the other end is engaged with a locking projection 31a protruding radially outward from the shaft portion 31. Similarly, a hook portion at one end of the tension coil spring _37C2 is engaged with the support _36-2 of the base main body 32, and a hook portion at the other end is engaged with the locking projection 31a of the shaft portion 31. A hook portion at one end of the tension coil spring _37C3 is engaged with the support _36-3 of the base body 32, and a hook portion at the other end is engaged with a locking projection 31b protruding radially outward from the shaft portion 31. A hook portion at one _end of the tension coil spring 37C4 is engaged with the support _36-4 of the base body 32, and a hook portion at the other end is engaged with the locking projection 31b of the shaft portion 31.

As a result, the shaft portion 31 (and therefore the actuator 3A) is elastically supported from the outer periphery by the tension coil springs _37C1 , _37C2 , _37C3 , and 37C4. Also, as shown in Figure 30, the tension coil springs _37C1 , _37C2 , _37C3 , and _37C4 are disposed between the base end portion 34 of the actuator _3A and the flange portion 31f, similar to the wires ₃₇₁ , ₃₇₂ , ₃₇₃ , and ₃₇₄ of the above embodiment.

Even in this fourth modified example, if the tip 30 of the actuator 3A is misaligned with respect to the actuator insertion hole 20 of the switch body 2 (see FIG. 8 of the previous embodiment), the misalignment is absorbed by the movement of the base end 34 of the actuator 3A via the ball bearing (see FIGS. 29 and 30). Not only can the misalignment of the actuator 3A with respect to the actuator insertion hole 20 be absorbed in any direction (arrow B direction) intersecting the actuator insertion direction (arrow A direction), but the base end 34 is supported via a ball bearing, so that the base end 34 can be reliably supported by the ball bearing when an excessive thrust load acts on the base end 34 when the actuator 3A is inserted.

Furthermore, when the tip 30 of the actuator 3A is inserted into the switch body 2 in a state where it is displaced upward (see FIG. 15 in the above embodiment), the tip 30 and the base end 34 move downward, causing the shaft 31 to move downward as well, at which point the upper tension coil springs _37C1 and _37C2 are tensilely deformed, and the lower tension coil springs _37C3 and _37C4 are tensilely deformed (see FIG. 31). At this time, an elastic repulsive force caused by the elastic deformation of the tension coil springs _37C1 , _37C2 , _37C3 and _37C4 acts upward on the outer periphery of the shaft 31.

Therefore, when the movable door is opened and the tip portion 30 of the actuator 3A attempts to leave the actuator insertion hole 20 of the switch body 2 as the movable door moves, the shaft portion 31 (and therefore the actuator 3A) attempts to move upward due to the elastic repulsive forces of the tension coil springs _37C1 , _37C2 , _37C3 , _37C4 acting on the shaft portion 31. At this time, the base end portion 34 of the actuator 3A is movable by the ball bearings, so the upward movement of the actuator 3A is smooth.

In addition, in Figure 31, an example has been described in which the actuator 3A is misaligned upward with respect to the actuator insertion hole 20, and as a result, the upper and lower tension coil springs _37C1 , _37C2 , _37C3 , and 37C4 are tensilely deformed when the misalignment is absorbed due to the actuator _3A being misaligned upward with respect to the actuator insertion hole _20. However, in the case of a downward misalignment, the upper and lower tension coil springs _37C1 , _37C2 , _37C3 , and _37C4 will similarly be tensilely deformed; in the case of a leftward misalignment, the right-side tension coil springs _37C1 and _37C4 will be compressively deformed and the left-side tension coil springs _37C2 and 37C3 will be tensilely deformed; and in the case of a rightward misalignment, the left-side tension coil springs _37C2 and _37C3 will be compressively deformed and the right-side tension coil springs _37C1 and _37C4 will be tensilely deformed. In addition, in this fourth modified example, the tension coil springs _37C1 , _37C2 are engaged with the locking projection 31a of the shaft portion 31, and the tension coil springs _37C3 , _37C4 are engaged with the locking projection 31b of the shaft portion 31. Therefore, when the shaft portion 31 attempts to rotate on its axis during movement of the actuator 3A, elastic restoring forces caused by the deformation of each of the tension coil springs _37C1 , _37C2 , _37C3 , _37C4 act on the shaft portion 31, thereby restricting the rotation of the shaft portion 31.

[Fifth Modification]
32 to 35 show a fifth modified example of the present invention (particularly a modified example of the first elastic support member), and in each figure, the same reference numerals as those in the above embodiment and the first to fourth modified examples indicate the same or corresponding parts. In the above embodiment, four wires each extending linearly are used, and the wires ₃₇₁ , ₃₇₂ , ₃₇₃ , ₃₇₄ are arranged in a lattice pattern in the vertical and horizontal directions (see Figs. 4 and 6), but in this fifth modified example, two endless type rubber bands 371 , ₃₇₂ are used as the _first elastic support member.

As shown in Fig. 32, rubber band ₃₇₁ is wound around the four support posts ₃₆₁ of base body ₃₂ from the outer periphery and arranged in a rectangular shape that is long in the vertical direction. Similarly, rubber band ₃₇₂ is wound around the four support posts ₃₆₂ of base body 32 from the outer periphery and arranged in a rectangular shape that is long in the left-right direction. Rubber band 371 is arranged on the front side of the paper in Fig. 32 with respect to rubber band _372. Each of rubber bands ₃₇₁ , ₃₇₂ elastically abuts against the outer periphery of shaft portion 31, and shaft portion 31 (and therefore actuator 3A) is elastically supported from the outer periphery by each of rubber bands ₃₇₁ , ₃₇₂ .

As shown in FIG. 34, the rubber bands 37 ₁ and 37 ₂ are disposed between the base end 34 of the actuator 3A and the flange portion 31f, similar to the wires 37 ₁ , 37 ₂ , 37 ₃ and 37 ₄ of the previous embodiment.

Even in this fifth modified example, if the tip 30 of the actuator 3A is misaligned with respect to the actuator insertion hole 20 of the switch body 2 (see FIG. 8 of the previous embodiment), the misalignment is absorbed by the movement of the base end 34 of the actuator 3A via the ball bearing (see FIGS. 33 and 34). Not only can the misalignment of the actuator 3A with respect to the actuator insertion hole 20 be absorbed in any direction (arrow B direction) intersecting the actuator insertion direction (arrow A direction), but the base end 34 is supported via a ball bearing, so that the base end 34 can be reliably supported by the ball bearing when an excessive thrust load acts on the base end 34 when the actuator 3A is inserted.

Furthermore, when the tip 30 of the actuator 3A is inserted into the switch body 2 in a state where it is displaced upward (see FIG. 15 of the above embodiment), the tip 30 and the base end 34 move downward, causing the shaft 31 to move downward as well, and at this time, the shaft 31 comes into contact with the lower span of the rubber band ₃₇₂ , elastically deforming it downward (see FIG. 35). Therefore, at this time, an elastic repulsive force caused by the elastic deformation of the lower span of the rubber band ₃₇₂ acts upward on the outer circumferential surface of the shaft 31.

Therefore, when the movable door is opened and the tip portion 30 of the actuator 3A tries to leave the actuator insertion hole 20 of the switch body 2 as the movable door moves, the shaft portion 31 (and therefore the actuator 3A) tries to move upward due to the elastic repulsive force of the lower span of the rubber band ₃₇₂ acting on the shaft portion 31. At this time, the base end portion 34 of the actuator 3A is movable by the ball bearing, so the upward movement of the actuator 3A is performed smoothly.

In addition, in Figure 35, an example has been described in which, due to an upward positional deviation of the actuator 3A with respect to the actuator insertion hole 20, the shaft portion 31 of the actuator 3A comes into contact with the lower span of the rubber band ₃₇₂ and elastically deforms the lower span downward when the positional deviation is absorbed. However, in the case of a downward positional deviation, the shaft portion 31 comes into contact with the upper span of the rubber band ₃₇₂ and elastically deforms the upper span upward, and in the case of a left or right positional deviation, the shaft portion 31 comes into contact with the left or right span of the rubber band ₃₇₁ and elastically deforms these spans to the left or right in Figure 32.

[Sixth Modification]
36 to 39 show a sixth modified example of the present invention (particularly a modified example of the first elastic support member), and in each drawing, the same reference numerals as those in the above embodiment and the first to fifth modified examples indicate the same or corresponding parts. In the above embodiment, the wires 37 ₁ , 37 ₂ , 37 ₃ , and 37 ₄ are provided inside the base portion 3B (see FIG. 5), but in this sixth modified example, the first elastic support member is provided outside the base portion 3B.

36 and 37, in the actuator unit 3, a rubber cover 4 is attached to the front end surface 32A and side surface 32B of the base body 32 of the base part 3B. The cover 4 has a bellows-shaped part (first elastic support member) 40 on the front end surface 32A of the base body 32, in which a through hole 40a through which the shaft part 31 is inserted is formed in the center. The inner peripheral surface of the through hole 40a of the bellows-shaped part 40 is in close contact with the outer peripheral surface of the shaft part 31, and the shaft part 31 is elastically supported by the bellows-shaped part 40. The bellows-shaped part 40 is formed concentrically from the through hole 40a toward the outside, and is configured to apply an elastic repulsive force to the outer peripheral surface of the shaft part 31 by expanding and contracting. The bellows-shaped part 40 also covers the through hole 32a formed in the front end surface 32A of the base body 32.

Even in this sixth modified example, if the tip 30 of the actuator 3A is misaligned with respect to the actuator insertion hole 20 of the switch body 2 (see FIG. 8 of the previous embodiment), the misalignment is absorbed by the movement of the base end 34 of the actuator 3A via the ball bearing (see FIGS. 37 and 38). Not only can the misalignment of the actuator 3A with respect to the actuator insertion hole 20 be absorbed in any direction (arrow B direction) intersecting the actuator insertion direction (arrow A direction), but the base end 34 is supported via a ball bearing, so that the base end 34 can be reliably supported by the ball bearing when an excessive thrust load acts on the base end 34 when the actuator 3A is inserted.

Furthermore, when the tip 30 of the actuator 3A is inserted into the switch body 2 while being displaced upward (see FIG. 15 in the above embodiment), the tip 30 and the base end 34 move downward, causing the shaft 31 to move downward as well, at which point the shaft 31 elastically deforms the bellows-shaped portion 40 downward (see FIG. 39). That is, in this case, the bellows-shaped region below the shaft 31 is compressively deformed, and the bellows-shaped region above the shaft 31 is tensilely deformed. Therefore, at this time, an elastic repulsive force due to the elastic deformation of the bellows-shaped portion 40 acts upward on the outer circumferential surface of the shaft 31.

Therefore, when the movable door is opened and the tip 30 of the actuator 3A tries to leave the actuator insertion hole 20 of the switch body 2 as the movable door moves, the elastic repulsive force of the bellows-shaped portion 40 acting on the shaft 31 causes the shaft 31 (and therefore the actuator 3A) to move upward. At this time, the base end 34 of the actuator 3A is movable by the ball bearing, so the actuator 3A moves upward smoothly.

In FIG. 39, an example is described in which the actuator 3A is displaced upward relative to the actuator insertion hole 20, and the shaft 31 of the actuator 3A elastically deforms the bellows portion 40 downward when absorbing the displacement. In the case of a downward displacement, the shaft 31 elastically deforms the bellows portion 40 upward, and in the case of a left-right displacement, the shaft 31 elastically deforms the bellows portion 40 to the left or right in FIG. 36.

[Seventh Modification]
40 and 41 show a seventh modified example of the present invention, and in each drawing, the same reference numerals as those in the above-described embodiment and the above-described first to sixth modified examples indicate the same or corresponding parts.

40, inside the base main body 32 of the base portion 3B, an elastic structure (second elastic support member) 5 composed of a compression spring or the like is provided behind the base end 34 of the actuator 3A (to the right in the figure ), and a flat hard plate 39 is disposed between the elastic structure 5 and the base end 34. The balls 35 of the base end 34 abut against the front end surface of the hard plate 39, and one end of the elastic structure 5 abuts against the rear end surface. The other end of the elastic structure 5 abuts against the front end surface of the lid 33 of the base portion 3B. As a result, the base end 34 and the hard plate 39 of the actuator 3A are elastically supported by the elastic structure 5 in the direction of the arrow A, which is the actuator insertion direction.

Although not shown, this seventh modified example is provided with a first elastic support member as shown in the above embodiment or any of the first to sixth modified examples.

Even in this case, if the tip 30 of the actuator 3A is misaligned with respect to the actuator insertion hole 20 of the switch body 2 (see FIG. 8 of the above embodiment), the misalignment is absorbed by the movement of the base end 34 of the actuator 3A via the ball bearing (see FIG. 41). Not only can the misalignment of the actuator 3A with respect to the actuator insertion hole 20 be absorbed in any direction (arrow B direction) intersecting the actuator insertion direction (arrow A direction), but the base end 34 is supported via a ball bearing, so that the base end 34 can be reliably supported by the ball bearing when an excessive thrust load acts on the base end 34 when the actuator 3A is inserted.

In addition, in this case, the hard plate 39 on which each ball 35 of the base end 34 rolls is elastically supported in the thrust direction by the elastic structure 5, so that the excessive thrust load acting on the base end 34 when the actuator 3A is inserted can be more effectively absorbed by the elastic compression deformation of the elastic structure 5.

In addition, when the tip 30 of the actuator 3A is inserted into the switch body 2 in a misaligned state (see FIG. 15 in the above embodiment), the tip 30, base end 34, and shaft 31 move, and an elastic repulsive force caused by the elastic deformation of the first elastic member (not shown) acts on the actuator 3A.

Therefore, when the movable door is opened and the tip 30 of the actuator 3A tries to leave the actuator insertion hole 20 of the switch body 2 as the movable door moves, the actuator 3A tries to move due to the elastic repulsive force of the first elastic member. At this time, the base end 34 of the actuator 3A is movable by the ball bearing, so the movement of the actuator 3A is smooth.

[Eighth Modification]
Figures 42 and 43 show an eighth variant of the present invention (particularly a variant of the seventh variant), and in each figure, the same symbols as those in the above-mentioned embodiment and the first to seventh variants indicate the same or corresponding parts.

As shown in FIG. 42, in this eighth modified example, instead of the flat hard plate 39 in the seventh modified example, an arc-shaped (or bowl-shaped/dish plate-shaped/disc spring-shaped) hard plate 39' is provided. The hard plate 39' has a concave arc-shaped surface 39'a on the front end side and a convex arc-shaped surface 39'b on the rear end side. Each ball 35 of the base end 34 abuts against the concave arc-shaped surface 39'a, and one end of the elastic structure 5 abuts against the convex arc-shaped surface 39'b. The other end of the elastic structure 5 abuts against the front end surface of the lid body 33 of the base part 3B. As a result, the base end 34 of the actuator 3A and the hard plate 39' are elastically supported by the elastic structure 5 in the actuator insertion direction A. Although not shown, in this eighth modified example, as in the seventh modified example, a first elastic support member shown in any of the above-mentioned embodiment or the first to sixth modified examples is provided.

Even in this case, if the tip 30 of the actuator 3A is misaligned with respect to the actuator insertion hole 20 of the switch body 2 (see FIG. 8 of the above embodiment), the misalignment is absorbed by the movement of the base end 34 of the actuator 3A via the ball bearing (see FIG. 43). Not only can the misalignment of the actuator 3A with respect to the actuator insertion hole 20 be absorbed in any direction (arrow B direction) intersecting the actuator insertion direction (arrow A direction), but the base end 34 is supported via a ball bearing, so that the base end 34 can be reliably supported by the ball bearing when an excessive thrust load acts on the base end 34 when the actuator 3A is inserted.

Furthermore, in this case, the hard plate 39' on which each ball 35 of the base end 34 rolls is elastically supported in the thrust direction by the elastic structure 5, so that the excessive thrust load acting on the base end 34 when the actuator 3A is inserted can be effectively absorbed by the elastic compressive deformation of the elastic structure 5. Moreover, in this case, the base end 34 moves along the concave arc-shaped surface 39'a of the hard plate 39', and the amount of compressive deformation of the elastic structure 5 becomes large on the side to which the base end 34 has moved (FIG. 43). Therefore, when the actuator 3A returns to its original position, in addition to the elastic repulsive force of the first elastic support member (not shown) acting on the actuator 3A, the elastic repulsive force of the elastic structure 5 acts on the actuator 3A via the hard plate 39', so that the actuator 3A can be smoothly returned to its original position.

[Ninth Modification]
Figures 44 and 45 show a ninth modified example of the present invention (particularly a modified example of the first elastic support member), and in each figure, the same reference numerals as those in the above-described embodiment and the first to eighth modified examples indicate the same or corresponding parts.

As shown in FIG. 44, the first elastic support member 37 according to the ninth modification is composed of a cylindrical portion 37A arranged on the inner periphery side and a protruding portion 37B protruding diagonally forward from the rear end (right end in the figure) of the cylindrical portion 37A, and the axial cross section of the cylindrical portion 37A and the protruding portion 37B is formed into a substantially V-shape. The inner periphery surface 37Aa of the cylindrical portion 37A is in close contact with the outer periphery surface of the shaft portion 31 between the base end portion 34 of the shaft portion 31 and the flange portion 31f. The outer periphery edge portion of the protruding portion 37B abuts against the inner wall surface of the base body 32. With this configuration, the shaft portion 31 (and therefore the actuator 3A) is elastically supported from the outer periphery side by the first elastic support member 37.

Even in this ninth modified example, if the tip 30 of the actuator 3A is misaligned with respect to the actuator insertion hole 20 of the switch body 2 (see FIG. 8 of the previous embodiment), the misalignment is absorbed by the movement of the base end 34 of the actuator 3A via the ball bearing (see FIG. 45). Not only can the misalignment of the actuator 3A with respect to the actuator insertion hole 20 be absorbed in any direction (arrow B direction) intersecting the actuator insertion direction (arrow A direction), but the base end 34 is supported via a ball bearing, so that the base end 34 can be reliably supported by the ball bearing when an excessive thrust load acts on the base end 34 when the actuator 3A is inserted.

Furthermore, when the tip 30 of the actuator 3A is inserted into the switch body 2 while being displaced upward (see FIG. 15 in the above embodiment), the tip 30 and the base end 34 move downward, causing the shaft 31 to move downward as well, and at this time, the shaft 31 elastically deforms the protruding portion 37B in the lower region of the first elastic support member 37 (see FIG. 45). Therefore, at this time, an elastic repulsive force due to the elastic deformation of the protruding portion 37B in the lower region of the first elastic support member 37 acts upward on the outer circumferential surface of the shaft 31.

Therefore, when the movable door is opened and the tip 30 of the actuator 3A attempts to leave the actuator insertion hole 20 of the switch body 2 as the movable door moves, the elastic repulsive force of the protruding portion 37B in the lower region of the first elastic support member 37 acting on the shaft 31 causes the shaft 31 (and therefore the actuator 3A) to move upward. At this time, the base end 34 of the actuator 3A is movable by the ball bearing, so the actuator 3A moves upward smoothly.

In FIG. 45, an example is shown in which the actuator 3A is displaced upward relative to the actuator insertion hole 20, and the shaft 31 of the actuator 3A elastically deforms the protrusion 37B in the lower region of the first elastic support member 37 when absorbing the displacement. In the case of a downward displacement, the shaft 31 elastically deforms the protrusion 37B in the upper region of the first elastic support member 37, and in the case of a left-right displacement, the shaft 31 elastically deforms the protrusion 37B in the left or right region of the first elastic support member 37 to the left or right.

[Tenth Modification]
Figures 46 to 52 are diagrams for explaining a safety switch including an actuator unit and a switch body according to a tenth modified example of the present invention. Figure 46 is a schematic diagram of the safety switch (corresponding to Figure 1 in the above embodiment), Figure 47 is a vertical cross-sectional view of the actuator unit (corresponding to Figure 5 in the above embodiment), Figures 48 to 50 are diagrams showing the movement of the actuator unit and the actuator in time series when the actuator unit is misaligned with respect to the actuator insertion hole of the switch body (corresponding to Figures 8 to 10 in the above embodiment), Figure 51 is a vertical cross-sectional view of the actuator unit after the actuator has moved (corresponding to Figure 13 in the above embodiment), and Figure 52 is a diagram showing a state in which the actuator is inserted into the switch body and the locking member inside the switch body is locked to the actuator (corresponding to Figure 15 in the above embodiment). In each figure, the same reference numerals as those in the above embodiment indicate the same or corresponding parts.

In this tenth modified example, the shape of the actuator is different from that of the previous embodiment. In the previous embodiment, the shaft 31 of the actuator 3A has a cylindrical shape (i.e., a circular cross section), and the tip 30 has a hemispherical shape with a convex arc-shaped surface 30a at the tip. In the tenth modified example, the shaft 31' of the actuator 3A' is plate-shaped (see Figures 50 and 52) (i.e., a rectangular cross section), and has a rounded portion (i.e., a convex arc-shaped surface) 31'r at the corner of the flat tip 31'a. In addition, a rectangular locking hole 31'b, for example, is formed in the area near the tip 31'a of the shaft 31', penetrating the shaft 31' in the thickness direction.

47 and 51, in this tenth modified example, the wires 37 ₁ to 37 ₄ in the above-described embodiment are used as the first elastic support member, but other members as shown in the above-described modified examples may be used as the first elastic support member. Also, since the shaft portion 31' of the actuator 3A' is plate-shaped, the opening 32a formed in the front end surface of the base body 32 of the base portion 3B may be rectangular rather than circular.

As shown in Figure 46, when the center line _3CL of the actuator 3A' coincides with the center line _2CL of the actuator insertion hole 20 of the switch body 2, the tip portion 31'a of the actuator 3A' does not interfere with the tapered surface 20a of the actuator insertion hole 20 during insertion, and the actuator can be smoothly inserted into the actuator insertion hole 20.

On the other hand, as shown in Fig. 48, when the center line _3CL of the shaft portion 31' (i.e., the actuator 3A') is misaligned with the center line _2CL of the actuator insertion hole 20 of the switch body 2, the rounded portion 31'r of the tip portion 31'a of the actuator 3A' abuts against the tapered surface 20a of the actuator insertion hole 20 when the actuator is inserted (see Fig. 49). As a result, while the movable door is closed, the rounded portion 31'r of the tip portion 31'a tries to move obliquely downward in the figure while sliding along the tapered surface 20a.

At this time, as shown in FIG. 47, each ball 35 protruding from the rear end surface of the base end 34 of the actuator 3A' is movable in the direction of arrow B along the inner surface of the lid body 33. When a force is applied to move the tip end 31'a of the actuator 3A' downward while the movable door is closed, as shown in FIG. 51, each ball 35 rolls on the inner surface of the lid body 33, causing the base end 34 to move downward along the inner surface of the lid body 33. This causes the actuator 3A' to move downward relative to the base portion 3B.

As a result, the radiused portion 31'r of the tip portion 31'a of the actuator 3A' moves diagonally downward along the tapered surface 20a of the actuator insertion hole 20 (Figure 49), and as shown in Figure 50, the actuator 3A' is inserted into the switch body 2 through the actuator insertion hole 20. Then, as shown in Figure 52, a locking member (e.g., a cam member) SR inside the switch body 2 locks the locking hole 31'b of the shaft portion 31' of the actuator 3A'. This locks the actuator 3A' and prevents it from coming loose. From this state, the contacts (not shown) inside the switch body 2 switch, and the operation of a machine such as a robot begins.

In this tenth modified example, similarly to the above embodiment, when a positional deviation occurs, the base end 34 of the actuator 3A' can move via the ball bearing to absorb the positional deviation, and can also absorb a positional deviation in any direction (arrow B direction) intersecting with the actuator insertion direction (arrow A direction). Furthermore, the ball bearing can reliably support an excessive thrust load acting on the base end 34 of the actuator 3A' when a positional deviation occurs. Furthermore, by using a ball bearing, the coefficient of friction can be reduced, and durability can be further improved. As in the previous embodiment, the elastic repulsive force caused by the elastic deformation of each of the wires 37 ₁ to 37 ₄ acts on the actuator 3A', causing the actuator 3A' to return to its original position. However, in this tenth modified example, since the shaft 31' of the actuator 3A' has a rectangular cross section, in order to smoothly insert the shaft 31' into the actuator insertion hole 20 and lock the shaft 31' into the locking hole 31'b by the locking member SR after insertion, it is preferable that the rotation of the shaft 31' is restricted, and in this respect the wires 37 ₁ to 37 ₄ clamp the shaft 31' from above, below, left and right (see the twelfth modified example (FIG. 54) described later). As a mechanism for restricting the rotation of the shaft 31', the mechanism according to the third modified example (FIG. 24) or the fourth modified example (FIG. 28) described above may be adopted.

[Eleventh Modification]
In the above embodiment, an example was shown in which the base end 34 of the actuator 3A holds five balls 35 (see Figs. 4 and 12), but application of the present invention is not limited to this. The number of balls 35 may be more or less than five. Fig. 53 shows an eleventh modified example of the present invention, which corresponds to Fig. 4 of the above embodiment, but Fig. 53 shows only the rear end surface of the base end 34.

As shown in FIG. 53, the base end 34 of the actuator 3A has five balls 35 arranged at equal or approximately equal intervals on the circumference, as well as one ball 35 arranged at the center or approximately the center. Various other arrangements of the balls 35 are possible, and the size of each ball 35 does not necessarily have to be the same.

In the above embodiment, the bottom of the holding hole 34a for the ball 35 is tapered (see FIG. 5), but the application of the present invention is not limited to this. The bottom of the holding hole 34a may be flat. Furthermore, the shape of the holding hole 34a does not necessarily have to be circular, but may be elliptical/oval/elliptical, or polygonal, and furthermore, one holding hole 34a may hold multiple balls 35.

In the above embodiment, the holding hole 34a is formed directly in the base end 34, but the application of the present invention is not limited to this. A thin-walled holding tool may be manufactured from a material with a low friction coefficient, and the holding tool may be inserted and fixed into a larger holding hole 34a, so that the ball 35 is held by the holding tool so that it can rotate freely.

In the above embodiment, the ball 35 is held at the base end 34, but the application of the present invention is not limited to this. The cover 33 may be made thick and multiple holding holes may be formed in it to hold the balls so that they can rotate freely, and the rear end surface of the base end 34 may be made flat so that each ball abuts against the rear end surface of the base end 34.

[Twelfth Modification]
Fig. 54 shows an actuator unit according to a twelfth modified example of the present invention, and corresponds to Fig. 6 of the above-mentioned embodiment. In the above-mentioned embodiment, an example was shown in which the shaft portion 31 of the actuator 3A had a circular cross section, but the shaft portion 31 may have a rectangular cross section. In the example shown in Fig. 54, a shaft portion 31A having a square cross section is shown. As shown in the figure, wires 37 ₁ to 37 ₄ are in contact with the four faces of the shaft portion 31A, respectively, so that the rotation of the shaft portion 31A is restricted when the actuator 3A moves when the actuator is inserted in the event of misalignment.

[Thirteenth Modification]
Fig. 55 shows an actuator unit according to a thirteenth modified example of the present invention, and corresponds to Fig. 16 of the first modified example. In the first modified example, an example was shown in which the shaft portion 31 of the actuator 3A has a circular cross section, but the shaft portion 31 may have a rectangular cross section. In the example shown in Fig. 55, a shaft portion 31B having a square cross section is shown. As shown in the figure, the movable arms ₃₇₁ to ₃₇₄ of the torsion coil springs _37C1 to _37C4 are in contact with the four faces of the shaft portion 31B, respectively. This restricts the rotation of the shaft portion 31B when the actuator 3A moves when it is inserted in the event of a positional deviation.

[Fourteenth Modification]
Fig. 56 shows an actuator unit according to a fourteenth modification of the present invention, and corresponds to Fig. 32 of the fifth modification. In the fifth modification, an example was shown in which the shaft 31 of the actuator 3A has a circular cross section, but the shaft 31 may have a rectangular cross section. In the example shown in Fig. 56, a shaft 31C having a square cross section is shown. As shown in the figure, rubber bands ₃₇₁ and ₃₇₂ are in contact with the four faces of the shaft 31C, respectively. This restricts the rotation of the shaft 31C when the actuator 3A moves when the actuator is inserted in the event of misalignment.

[Fifteenth Modification]
In the tenth modified example, an example was given in which the actuator insertion hole 20 of the switch body 2 has a tapered surface 20a, and the corners of the tip end 31'a of the actuator 3A' have a rounded portion (i.e., a convex arc-shaped surface) 31'r, but the application of the present invention is not limited to this. The actuator insertion hole 20 may have a convex arc-shaped surface, and the corners of the tip end 31'a of the actuator 3A' may have a chamfered portion (i.e., an inclined surface).

[Modification 16]
The tapered surface 20a (FIG. 1) provided in the actuator insertion hole 20 of the switch body 2 may be extended (not shown) to a position adjacent to the locking member SR (FIG. 7) inside the switch body 2. In this case, even if the actuator 3A is misaligned in either the up-down direction or the left-right direction or both, when the actuator 3A moves along the tapered surface 20a to a position adjacent to the locking member SR, the misalignment of the actuator 3A is eliminated, and this makes it possible to reliably lock the actuator 3A with the locking member SR.

[Seventeenth Modification]
In the above embodiment, an example was shown in which the shaft portion 31 of the actuator 3A has a smaller diameter than the hemispherical tip portion 30, but the application of the present invention is not limited to this. The shaft portion 31 may have substantially the same diameter as the tip portion 30, and a recess or a recessed groove/circumferential groove (not shown) having a smaller diameter than the tip portion 30 and the shaft portion 31 may be formed between the tip portion 30 and the shaft portion 31, and the locking member SR may be locked in these recesses or the like. Alternatively, in the above embodiment, a large diameter portion having substantially the same diameter as the tip portion 30 and a larger diameter than the shaft portion 31 may be provided at a longitudinal intermediate position of the small diameter shaft portion 31, with a gap (functioning as a locking recess for the locking member SR) between the tip portion 30 and the small diameter shaft portion 31.

In these cases, after the tip 30 of the actuator 3A enters the inside of the switch body 2, the shaft 31 or the large diameter portion, which has substantially the same diameter as the tip 30, enters the inside of the switch body 2 along the tapered surface 20a while abutting against the tapered surface 20a of the actuator insertion hole 20. Therefore, even if the actuator 3A is misaligned in either the up-down or left-right direction or both, when the actuator 3A moves to the position of the locking member SR, the misalignment of the actuator 3A is eliminated, and this allows the actuator 3A to be reliably locked by the locking member SR.

[Other Modifications]
The above-described embodiment and each modification should be considered in all respects as merely illustrative of the present invention, and not restrictive. Those skilled in the art to which the present invention pertains may, when considering the teachings above, construct various modifications and other embodiments that incorporate the principles of the present invention without departing from the spirit and essential characteristics of the present invention, even if not expressly described herein.

The present invention is useful for an actuator unit and a safety switch equipped with the same.

1: Safety switch

2: Switch body 20: Actuator insertion hole

3: Actuator unit 3A, 3A': Actuator 30, 31'a: Tip portion 30a: Convex arc surface 31, 31': Shaft portion 31'b: Locking hole 31'r: R portion (convex arc surface)
32a: Opening hole 34: Base end (holding part)
34a: Retaining hole 35: Ball 3B: Base portion 37 ₁ to 37 ₄ : Wires (first elastic support member)
37C ₁ to 37C ₄ : Torsion coil spring/tension coil spring (first elastic support member)
37 ₁ , 37 ₂ : Rubber band 37C: Spiral spring (first elastic support member)
39': Arc-shaped hard plate (arc-shaped plate member)
39'a: Concave arc surface 40: Bellows portion (first elastic support member)

5: Elastic structure (second elastic support)

SR: Locking member

A: Actuator insertion direction B: Direction intersecting with the actuator insertion direction

JP 2017-91877 A (see paragraphs [0037], [0038], [0044], FIG. 1, and FIG. 13 to FIG. 15) JP-A-8-138500 (see paragraphs [0009] and [0020], and Figs. 1 to 3) JP-A-11-317132 (see claim 1, paragraphs [0011] and [0012], Figs. 1, 3, and 4)

Claims (12)

An actuator unit comprising:
an actuator having a tip portion that can be inserted into the actuator insertion hole;
a base portion that supports a base end portion of the actuator via a ball bearing so as to be freely movable in any direction intersecting an insertion direction of the actuator into the actuator insertion hole,
a positional deviation between the tip end of the actuator and the actuator insertion hole is absorbed in any direction by movement of the base end of the actuator via the ball bearing;
1. An actuator unit comprising: In claim 1,
the base end of the actuator has a holding portion that rotatably holds a plurality of balls, and the balls and the holding portion constitute the ball bearing;
1. An actuator unit comprising: In claim 1,
The tip portion has a convex arcuate surface or an inclined surface.
1. An actuator unit comprising: In claim 1,
a first elastic support member is provided on the base portion to elastically support the actuator from an outer periphery thereof;
1. An actuator unit comprising: In claim 1,
the actuator has a shaft portion extending between the tip portion and the base portion, and the base portion has an opening through which the shaft portion is inserted to allow the movement of the base portion.
1. An actuator unit comprising: In claim 5,
A step is formed between the shaft portion and the tip portion.
1. An actuator unit comprising: In claim 5,
a first elastic support member is provided on the base portion to elastically support the shaft portion of the actuator from an outer periphery thereof;
1. An actuator unit comprising: In claim 7,
The first elastic support member covers the opening.
1. An actuator unit comprising: In claim 1,
The actuator has a locking hole that is engaged with a locking member inside a switch body having the actuator insertion hole.
1. An actuator unit comprising: In claim 1,
a second elastic support member that elastically supports the base end of the actuator in the insertion direction of the actuator is provided on the base portion;
1. An actuator unit comprising: In claim 10,
a circular arc-shaped plate member having a concave circular arc surface forming a rolling surface of the ball bearing is provided on the base portion, and the circular arc-shaped plate member is elastically supported by the second elastic support member;
1. An actuator unit comprising: The actuator unit according to claim 1 ;
a switch body having the actuator insertion hole;
With safety switch.

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