JP3345202B2 - Blade mounting device for reciprocating cutting tool - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reciprocating cutting tool for cutting a plate material by reciprocating a blade (saw blade) such as a jigsaw.

[0002]

2. Description of the Related Art In general, in such a cutting tool, a blade is attached substantially coaxially to the tip of a reciprocating rod. Various attachment devices have been provided for this purpose. As a mode, for example, a configuration in which a blade is attached / detached by rotating an operation knob as disclosed in Japanese Patent Publication No. 3-503382 is known. In the case of such a configuration, it is desirable to interpose a torque limiting means in order to prevent the operation knob from being overtightened, and the same publication discloses various types of torque limiting means. FIG. 7 shows an example of the torque limiting means shown in FIG. 7 of the publication.

This conventional torque limiting means includes an operation knob 157 rotatably provided on a jigsaw body, a claw bush 155 provided rotatably independently of the operation knob 157, and a claw bush 155. Is a ratchet member 154 that rotates integrally with a rotation torque of a certain value or less.
Is disposed on the upper surface of the operation knob 157, and can be displaced within a certain range in the axial direction (vertical direction in the drawing), but is always rotated integrally with the operation knob 157 and displaced upward in the axial direction even when displaced. An operating member 163 that is connected with the claw bush 155 only for rotation only when necessary is provided. The ratchet member 154 is fixed to the head of the rod 130. When the ratchet member 154 is rotated, the rod 1
The blade 30 is also rotated, and the blade holding means is operated through the rotation of the rod 130 to attach and detach the blade.

[0004] According to such a configuration, the blade mounting and
When the operating member 163 is lifted to the upper position in the figure at the time of removal, the spline 169 formed at the tip of the shaft portion 168 of the operating member 163 is moved to the claw bush 1.
The operation member 163 and the claw bush 155 are connected for rotation because they are engaged with the spline 170 formed on the upper surface of the 55. The head 164 of the operating member 163 is provided with a pair of outward lugs 166, 166. The operating member 163 does not protrude from the slots 167, 167 formed in the operating knob 157. Since the operation member 163 can be displaced in the axial direction only within the range, the operation member 163 is always rotated integrally with the operation knob 157. Therefore, in this case, when the operation knob 157 is rotated, the claw bush 155 is integrally rotated.

[0005] Fingers 135-1 are provided on the claw bush 155.
35 are provided, and the fingers 135 to 135 are slots 1 provided on the peripheral surface of the ratchet member 154, respectively.
36 is rotationally engaged. Since the wall of the slot 136 in the blade mounting direction is inclined, if the rotation of the claw bush 155 performed through the rotation operation of the operation knob 157 is performed with a rotation torque of a certain value or less, the claw bush 155 and the ratchet member 154 are formed. Are rotated integrally, so that the blade holding means is operated through the rod 130. When a predetermined rotation torque is applied to the claw bush 155, each finger 135
Is separated from the slot 136 against the spring force, so that the two 155 and 154 are separated from each other for rotation, so that the operation knob 157 idles and over-tightening of the blade holding means is prevented. On the other hand, the engagement surface of the slot 136 in the blade removing direction is not inclined (substantially formed along the normal direction), so that when the operation knob 157 is rotated in the blade removing direction, the rotational torque is reduced. Finger 13 regardless of size
5 is not disengaged from slot 136, so that the operating knob 157 can be rotated with the required torque to remove the blade.

On the other hand, after the blade is attached, the operating member 163 is pushed into the lower pushing position in the figure. When the operation member 163 is displaced to the lower position, the spline 169 is moved to the spline 1 of the claw bush 155.
70, the operation member 163 and, consequently, the operation knob 157 and the claw bush 155 are separated from each other for rotation. Therefore, the operation knob 157 idles and the blade holding means cannot be operated.
When the cutting operation is performed while holding the grip 7 as a grip, the blade holding means is not operated even if the operation knob 157 is rotated, so that the blade is prevented from falling off.

[0007]

However, with the above configuration, the operation member 163 needs to be raised to an upper position when the blade is mounted, and pushed back downward after the blade is mounted, so that the operation is troublesome. For this reason, there is a possibility that the operation member 163 may be forgotten to be returned downward after the blade is attached. Since the blade holding means is operable in a state where the operation member 163 is raised to the upper position, when the cutting operation is performed while holding the operation knob 157 as a grip, the operation knob 15
7 may be rotated in the blade removal direction and the blade may fall off.

The present invention has been made in view of this problem, and a blade mounting apparatus for a reciprocating cutting tool that can reliably prevent the blade from falling off even when the cutting operation is performed while holding the operation knob as a clip. The purpose is to provide.

[0009]

SUMMARY OF THE INVENTION Therefore, the present invention provides
The blade mounting device has the configuration described in each claim .

According to the first aspect of the present invention, when the operating member is rotated in the blade mounting direction with a rotational torque within a certain range, the blade holding means is operated in the blade mounting direction via the torque limiting means. In addition, the blade can be mounted without operating a special member (operation member 163) as in the related art. Accordingly, there is no member to be returned after the blade is attached, unlike the conventional case, and there is no need to forget to return. Moreover, since the torque limiting means does not transmit the rotational torque in the blade removing direction, the blade holding means is not operated even if the operating member is rotated in the blade removing direction, so that the blade is not loosened. For this reason, when the cutting operation is performed while holding the operating member as a grip after the blade is attached, the blade does not fall off even if the operating member is rotated in the blade removing direction.

On the other hand, the removal of the blade is performed by operating the direct connection means to directly connect the operating member and the blade holding means for rotation. As described above, the conventional problem can be solved by separating the transmission path of the rotational torque at the time of attaching the blade (the path through the torque limiting means) and the transmission path of the rotational torque at the time of removing the blade (the path through the direct connection means). You. In this regard, conventionally, by providing the engagement surface of the slot 136 in the blade removal direction substantially along the normal direction (without being inclined, that is, in a substantially directly connected state), the transmission path of the rotational torque at the time of blade attachment and the blade The transmission path of the rotational torque at the time of removal was the same configuration.

According to the second aspect of the invention, the transmission of the rotational torque in the blade mounting direction between the operating member and the blade holding means is performed by engaging the clutch teeth of the first clutch member and the second clutch member. . However, since the inclination angle of the tooth surface that comes into contact with each clutch tooth when the blade is removed is smaller than the tooth surface that comes into contact when the blade is attached, the operating member is rotated in the blade removal direction with the blade firmly attached. However, the clutch teeth are disengaged and do not mesh with each other, so that a large rotating torque required at the time of blade removal is not transmitted to the blade holding means, and therefore, the blade holding means is not operated in the blade removing direction.

[0013]

According to the first or second aspect of the present invention,
Even when the cutting operation is performed while holding the operation member as a grip, the blade can be reliably prevented from falling off.

[0014]

1 to 3 show a first embodiment of the present invention.
It will be described based on. FIG. 1 shows substantially the entire jigsaw 1 provided with the blade mounting device of the present embodiment. In this example, except for the blade mounting device, there is no need to change it in particular, so it will not be described in detail. In the figure, reference numeral 2 denotes a main body housing, and a motor as a drive source of the jigsaw 1 is provided inside the main body housing 2. , And reference numeral 3 indicates an output shaft of the motor. The rotation output of the motor is converted to linear motion via the conversion mechanism 4, whereby the rod 21 reciprocates in the vertical direction.
The rod 21 is connected to the main housing 2 by the bearings 2a and 2b.
At the front portion (left end in the figure) of the front panel is supported so as to be able to reciprocate up and down.

The blade mounting apparatus of this embodiment is roughly divided into blade holding means 1 for mounting the blade B.
1 and an operating mechanism 60 including an operating member 61 for rotating and operating the blade holding means 11. The blade holding means 11 includes an operating rod 31
Is rotated about its axis to open and close the pawl 41 so that the blade B can be attached and detached. That is, the blade holding means 11 includes the rod 21 described above and the operating rod 3 disposed inside the inner peripheral hole 21 a of the rod 21 so as to be rotatable around the axis and movable in the axial direction.
1, a claw 41 for sandwiching the blade B, and a claw 4
1 is provided with a holder 51 for giving an opening and closing operation.

The rod 21 has a substantially cylindrical shape, and a roller guide 4a having a U-shaped cross section, which constitutes the conversion mechanism 4, is mounted at substantially the center in the axial direction at right angles to the axial direction. The inner peripheral hole 21a of the rod 21 is formed to penetrate vertically, and a screw hole 21c for a left-handed screw is formed at a certain position in the axial direction at an intermediate position in the axial direction.

The operating rod 31 has a diameter that can be inserted into the inner peripheral hole 21a of the rod 21, and has a left-hand thread 31a and a right-hand thread 31b formed coaxially at its tip. I have. The left screw portion 31a is the left screw hole 2 of the rod 21.
Since the operation rod 31 is rotated counterclockwise, it moves downward in the figure, and when rotated clockwise, moves upward in the figure. The right screw part 31b is
Is screwed into a right screw hole 41c formed in the cylindrical body portion 41a. The claw 41 is accommodated in a holder 51 attached to the tip of the rod 21 and is supported so as to be movable in the vertical direction and non-rotatably, so that when the operation rod 31 is rotated counterclockwise, it is attached to the operation rod 31. On the other hand, it moves downward in the figure, and when rotated clockwise, moves upward in the figure. From this, the pawl 41 is connected to the rod 2 of the operating rod 31.
1 and the moving distance with respect to the operating rod 31 itself are moved with respect to the rod 21 by a total distance, so that a slight rotation of the operating rod 31 causes a large movement. The portion of the operation rod 31 above the left threaded portion 31a is formed in a semicircular cross section to form a semicircular rod portion 31c, which will be described later.

The claw 41 has a configuration in which a forked claw portion is provided at the tip of the cylindrical body portion 41a. Although not shown, inclined surfaces are formed on the back surfaces of both claw portions. An inclined surface formed on the holder 51 is slidably contacted with the inclined surfaces of both claw portions, and when the claw 41 is moved in the vertical direction in the figure through the rotation of the operation rod 31 by the action of the inclined surfaces of both. The pawl portion is opened and closed, whereby the blade B is attached and detached.

Next, an operation mechanism 60 for operating the blade holding means 11 configured as described above will be described. A substantially cylindrical case 64 is attached to the upper end of the main body housing 2 via a base 63, and an operation member 61 having a substantially bowl shape is put on the upper portion of the cylindrical case 64. By inserting a mounting screw 65 into a circumferential groove 64a formed on the peripheral surface of the cylindrical case 64, the mounting screw 65 is rotatably mounted on the cylindrical case 64 so as not to come off. This operation member 61
Has a function of attaching and detaching the blade B via the blade holding means 11 by rotating, and also has a function as a grip for an operator to grip during a cutting operation. The operation member 61 is arranged at an appropriate position as a grip, and has a shape and a size that can be easily gripped.

On the inner peripheral side of the cylindrical case 64, a torque limiting means 70 mainly composed of a first clutch member 71 and a second clutch member 72 each having a substantially disk shape is incorporated. The two clutch members 71 and 72 are rotatable with respect to the cylindrical case 64, respectively.
Is integrated with the operation member 61 via the pin 67, so that it is rotated integrally with the operation member 61 and does not move in the vertical direction in the figure. On the other hand, the second clutch member 72 is movable in the vertical direction in the figure, and the compression coil springs 66a and 66b are interposed between the lower surface and the base 63.
It is urged in the direction to be pressed against.

On the opposing surfaces of the two clutch members 71 and 72, there are formed clutch teeth 71a and 72a which mesh with each other in the rotational direction. FIG. 3 shows two clutch teeth 71a and 72a.
In the meshing state. This meshing state is when the operating member 61 is rotated clockwise to mount the blade B, and thus when the first clutch member 71 is rotated clockwise (to the left in FIG. 3). At this time, the inclination angles of the tooth surfaces (hereinafter referred to as “meshing tooth surfaces at the time of attachment”) 71b and 72b which are in contact with each other are as follows:
The tooth surfaces that are not in contact (therefore, the tooth surfaces that come into contact when the blade is removed, hereinafter referred to as “meshing tooth surfaces when removed”) 71c and 72c are steeper than the inclination angles. At the time of mounting, the inclination angles of the meshing tooth surfaces 71b and 72b are as follows.
Since the transmission is set based on the maximum rotational torque that is allowed to be transmitted, the first clutch member 71
When a rotational torque greater than the allowable value is applied to the second clutch member 72, the second clutch member 72 escapes downward against the compression coil springs 66a and 66b, so that the clutch teeth 71a of the first clutch member 71 Clutch teeth 7
2a, so that both clutch members 71, 72
Are idle and the rotational torque is interrupted.

On the other hand, at the time of removal, the meshing tooth surfaces 71c, 72
c is a tooth surface which is brought into contact when the operation member 61 is rotated counterclockwise to remove the blade B and the first clutch member 71 is rotated counterclockwise (moves to the right in FIG. 3). Therefore, when the blade is removed, a smaller rotational torque can be transmitted than when the blade is attached. For this reason,
When the blade B is firmly attached, the operating member 61
Is rotated counterclockwise, the first clutch member 71 idles, and the rotational torque is not transmitted to the second clutch member 72, so that the blade holding means 11 is not operated in the removing direction.

Next, the cylindrical portion 62c of the rotating rod 62 is inserted through the inner peripheral sides of the two clutch members 71 and 72. The first clutch member 71 and the cylindrical portion 62c are rotatable with each other, but the second clutch member 72 and the cylindrical portion 62c are engaged with each other via the pin 73 in the rotational direction. The rotating rod 62 rotates integrally with the second clutch member 72. However, the second clutch member 72 is vertically movable with respect to the rotating rod 62 because the axial displacement is not engaged.
The rotating rod 62 is immovable in the axial direction by the flange portion 62d formed above the cylindrical portion 62c and the pin 73.

The rotary rod 62 has a semicircular rod portion 62b having a semicircular cross section on the lower surface of the cylindrical body portion 62c.
This semicircular rod portion 62b is inserted into the rod 21,
The flat portion 62a is brought into sliding contact with the flat portion 31d of the semicircular rod portion 31c of the operation rod 31.
For this reason, when the rotating rod 62 is rotated around its axis through the rotation of the second clutch member 72, the operating rod 31 is also integrally rotated, whereby the operating rod 31 is moved in the axial direction as described above. The pawl 41 is opened and closed, and the blade B is attached and detached.

On the other hand, the flange portion 6 of the cylindrical portion 62c
A prismatic portion 62e having a rectangular cross section is integrally formed on the upper surface of 2d, and this prismatic portion 62e protrudes from the upper surface of the cylindrical case 64 and is inserted into a switching hole 80a of a directly connected plate 80 described below. .

Next, the direct connection plate 80 corresponds to the direct connection means described in the claims, and in a gap between the upper surface of the cylindrical case 64 and the operation member 61, a direction perpendicular to the rotating rod 62 ( It is slidably disposed in the left and right directions in the figure. As shown in FIG. 2, on the lower surface of the operating member 61, two spring pins 68, 68 other than the above-described pin 67 are protruded. Are guided, and the directly connected plate 80 is slidable in the left-right direction in the figure and is rotated integrally with the operation member 61.

The switching hole 80a described above is formed substantially at the center of the direct connection plate 80.
Reference numeral 0a denotes a center circular hole 80b, a slide support groove 80c formed by cutting in front of the circular hole 80b in the sliding direction (left side in the figure), and a rear side in the sliding direction (right side in the figure).
And a directly connected groove 80d formed by cutting. In the switching hole 80a, the pin 67 and the rotating rod 6 described above are provided.
The second prism portion 62e is inserted. For this reason, the direct connection plate 80 has the pin 67
c (a position indicated by a solid line, hereinafter referred to as a “non-direct connection position”) and the prism body portion 62e are connected to the direct connection groove 80d.
Can be slid between a position in contact with the rear end (a position indicated by a two-dot chain line; hereinafter, referred to as a “direct connection position”), and when the drawing operation is performed to the direct connection position, the front end protrudes from the peripheral edge of the operation member 61. On the other hand, when it is pushed into the non-directly connected position, it does not protrude from the same peripheral edge.

Further, since the direct connection groove 80d is formed with a necessary and sufficient width to insert the prism portion 62e of the rotating rod 62, the direct connection plate 80 is pulled out to the direct connection position to operate the same prism column. The body portion 62e is connected to the directly connected groove 80d.
When it is positioned inside, the rotation of the prism body portion 62e and thus the rotation rod 62 is restrained by this directly connected plate 80,
Therefore, the rotating rod 62 is directly connected to the operating member 61 and does not pass through the torque limiting means 70, and is switched to a rotating state. On the other hand, when the direct connection plate 80 is pushed into the non-direct connection position, the prism portion 62e is switched to the switching hole 80a.
The rotary rod 62 is not restricted by the direct connection plate 80, and is rotated by the rotation of the operation member 61 via the torque limiting means 70 as described later.

According to the blade mounting apparatus of the first embodiment configured as described above, the blade B is mounted and removed as follows. That is, as described above, the pawl 41 is moved up and down through the rotation of the operating rod 31 to open and close the claw portion, thereby mounting and removing the blade B.
Is performed by rotating the rotating rod 62, and the rotating of the rotating rod 62 is performed by rotating the operation member 61.

When the blade B is mounted, the direct connection plate 80 is pushed into the non-direct connection position, and in this state, the head of the blade B is inserted between both claws to rotate the operation member 61 clockwise. . In this case, the rotating rod 31 is moved from the operating member 61 → the pin 67 → the first clutch member 7
The first clutch member 72 is rotated through the path of the pin 73. At this time, if it is attempted to rotate the operating member 61 with a rotational torque equal to or greater than the allowable value, the second clutch member 72 is pushed downward against the compression coil springs 66a and 66b, and thereby the clutch of the first clutch member 71 Tooth 7
1a gets over the clutch teeth 72a of the second clutch member 72, and the first clutch member 71 and the second clutch member 72 are disengaged. Therefore, the rotational torque of the operating member 61 is applied to the second clutch member 72, that is, the rotating rod 62. This prevents the transmission from being transmitted, thereby preventing the rotation rod 62 and the like from being overloaded.

When the operating member 61 is rotated counterclockwise to remove the blade B thus mounted, the tooth surfaces 71c, 72c at the time of removal of the clutch teeth 71a, 72a abutting at this time become the tooth surfaces 71b at the time of mounting. , 72b, the first clutch member 71 has a smaller rotational torque than when the blade is mounted.
The second clutch member 72 is disengaged from the second clutch member 72, so that the rotating rod 62 is not rotated.
Is not operated in the removal direction. From this, when the cutting operation is performed while holding the operation member 61 as a grip after the blade B is attached, the blade holding means 11 is not operated even if the operation member 61 is rotated, and therefore the blade is not operated. The attachment of B does not come loose and fall off.

Next, when removing the blade B, the direct connection plate 80 is pulled out to the direct connection position. As a result, the prismatic portion 62e of the rotating rod 62 is relatively positioned in the direct connection groove 80d of the switching hole 80a, so that the rotating rod 62 is directly connected to the operation member 61 without passing through the torque limiting means 70 for rotation. Therefore, the rotation torque of the operation member 61 is directly transmitted to the rotation rod 62 via the direct connection plate 80. Therefore, in this case, when the operation member 61 is rotated counterclockwise to remove the blade B, the first clutch member 71 and the second clutch member 72 do not mesh as described above, but the rotation rod 62 rotates counterclockwise. Thus, the blade holding means 11 is operated in the blade removing direction, and the blade B can be removed.
The pull-out operation of the direct connection plate 80, that is, the above-described direct connection state only needs to be considered when a large operation force is required in the first stage of the rotation operation. Returning to the direct connection position, the operation member 61
Is transmitted to the rotating rod 62 to remove the blade B.

As described above, when the blade B is mounted, the blade holding means 11 is operated by rotating the operating member 61 clockwise without operating a special member as in the prior art, and the blade B is moved. It can be mounted by sandwiching it between both claws. In addition, in this state, even if the operation member 61 is rotated counterclockwise, the rotation torque is not transmitted to the rotation rod 62, so that the blade holding means 11 cannot be operated in the blade removal direction. Thus, when the cutting operation is performed while the operation member 61 is gripped as a grip, the attachment of the blade B is prevented from loosening and falling off even if the operation member 61 is rotated counterclockwise. Needless to say, even in the case of clockwise rotation, the torque limiting means 70 functions as long as the rotational torque becomes equal to or more than a certain value, so that the rotating rod 62 and the like are not overloaded. When the blade B is removed, if the direct connection plate 80 is pulled out to the direct connection position, the operation member 61 and the rotating rod 62 are directly connected without passing through the torque limiting means 70. By rotating, the blade holding means 11 is operated in the blade removing direction, and the blade B can be removed.

As described above, conventionally, the engagement surface of the slot 136 in the blade removal direction is provided substantially along the normal direction. Therefore, if the operation member 163 is lifted to the upper position, the blade can be attached and removed. If the operation member 163 is forgotten to be returned after the blade is mounted, the blade may fall off. However, according to the blade mounting device of this example, the transmission path of the rotational torque at the time of mounting the blade, the blade Since the transmission path of rotational torque at the time of removal is separate,
After the blade is attached, even if the cutting operation is performed while holding the operation member 61 as a grip in the state as it is, the blade B
Is reliably prevented from falling off.

Next, various changes can be made to the operation mechanism section 60 described above. The same reference numerals are used for members or parts that do not need to be changed, and the second and third embodiments of the operation mechanism will be described below. In the first embodiment, the direct connection plate 80 has a configuration in which both the pull-out operation and the push-in operation are manually performed. However, in the second embodiment shown in FIG. 4, for example, the operation of pulling out the direct connection plate 81 to the direct connection position is performed manually. The pressing operation to the non-directly connected position is automatically performed by the compression coil spring 82. That is, the rear end portion (right end portion in the figure) of the direct connection plate 81 is bent upward so as to rise, and the bent edge 81a enters the groove portion 61a formed on the lower surface of the operation member 61. This groove 6
The compression coil spring 82 is interposed between the front wall surface 61b of 1a and the bent edge 81a, so that the direct connection plate 81 is urged in the pushing direction (rightward in the drawing). On the other hand, a switching hole 80a similar to that of the first embodiment is formed at substantially the center of the direct connection plate 81. Therefore, when no operation is performed, the direct connection plate 81 is located at the pushing position, and The state is such that the body portion 62e is located in the circular hole 80b of the switching hole 80a, that is, the rotating rod 62 and the operating member 61 are not directly connected.

According to such a configuration, when the blade B is detached and the direct connection plate 81 is pulled out against the compression coil spring 82, the rectangular column 6 of the rotating rod 62 is pulled out.
2e is located in the direct connection groove 80d of the switching hole 80a, so that if the operating member 61 is rotated counterclockwise while maintaining the drawn state, the rotating rod 62 is rotated in a state directly connected to the operating member 61 to hold the blade. Means 11 is operated in the blade removal direction. As in the first embodiment, the pull-out operation of the direct connection plate 81 only needs to be performed when a large operation force is required in the initial stage of the rotation operation. 81 can be returned to the non-directly connected position, and the rotating rod 62 can be rotated via the torque limiting means 70. Here, when the finger is released from the direct connection plate 81 to stop the drawing operation, the direct connection plate 81
Is automatically returned to the pushing direction by the rotation rod 62.
Then, when the operation member 61 is rotated counterclockwise, the rotating rod 62 is rotated counterclockwise through the torque limiting means 70, and the blade holding means 11 is further removed. Operated in the direction. On the other hand, it is not necessary to operate the direct connection plate 81 at the time of mounting the blade.

As described above, when the pull-out operation is stopped, the direct connection plate 81 is automatically returned to the pushed-in position, and the direct connection state between the rotating rod 62 and the operating member 61 is released. An erroneous operation in which the operation member 61 is gripped as a grip and rotated in the blade loosening direction while being in the directly connected state due to forgetting to return is reliably avoided, and thus the blade B can be more reliably prevented from falling off during the cutting operation.

Next, the operation direction of the direct connection plate 83 in the third embodiment shown in FIG. 5 is opposite to that in the second embodiment. That is, a cut and raised claw 83a is formed near the rear end of the directly connected plate 83, and the cut and raised claw 83a is formed.
Similarly, the compression coil spring 84 is interposed between the rear wall surface 61c and the groove 61a formed on the lower surface of the operation member 61. Therefore, the direct connection plate 83 is urged in the drawing direction (left side in the drawing) and is always Is located at the extraction position, and is configured to be pushed in against the compression coil spring 84. In addition, almost at the center of the directly connected plate 83, FIG.
As shown in the figure, there is provided a switching hole 83b composed of a circular hole 83c and a groove 83d formed by cutting forward (leftward in the figure) from the circular hole 83c. The second embodiment differs from the circular hole 83c and the groove 83d in the second embodiment. Is upside down. According to such a configuration, when the direct connection plate 83 is pushed, the rotating rod 62 and the operating member 61 are directly connected, the blade holding means 11 can be operated in the blade loosening direction, and if the pushing operation is stopped, the direct connection plate 83 becomes Since the operation member 61 is automatically returned to the pull-out position, the direct connection plate 83 is not forgotten to be returned, that is, remains in the directly connected state at the stage of performing the cutting operation while gripping the operation member 61 as a grip. Is reliably prevented from falling off. Further, since the pushing direction is manually operated, the operability is better than that of the second embodiment in which the drawing direction is manually operated.

In consideration of ordinary operability, it is preferable that the blade B is attached when the operation member 61 is rotated clockwise and is removed when the operation member 61 is rotated counterclockwise. This point is assumed in each of the embodiments. Accordingly, the screw portions 31a and 31b or the claw portions and the inclined surfaces of the holder 51 are appropriately set, and when the operation member 61 is rotated counterclockwise, the claw portions are closed and the blade B is mounted. It is also possible to achieve the same effect.

Further, in the above embodiment, the blade B is attached and opened by opening and closing the claw portion through the movement of the claw 41.
Although the blade holding means 11 is shown as being detached, the blade holding means is not limited to this structure. For example, the blade holding means may be configured to hold the head of the blade B and hook the protrusion projecting in a T-shape. In other words, the present invention can be applied to any blade holding means configured to attach / detach the blade B by rotating the operation member 61. Further, the direct connection means is exemplified by the band-shaped direct connection plate 80, but the cylindrical portion 62 of the rotating rod 62 is used.
The same operation may be performed by inserting and removing a pin with respect to c, and various modifications may be made without departing from the scope of the claims. Also,
The blade attachment device according to the present invention is not limited to the illustrated jigsaw, but can be applied to, for example, a reciprocating saw.

[Brief description of the drawings]

FIG. 1 is a partially cutaway side view of a jigsaw provided with a blade attaching device according to a first embodiment of the present invention.

FIG. 2 is a plan view of a direct connection plate, taken along the line AA of FIG. 1;

FIG. 3 is a partially developed view showing an engaged state of a first clutch member and a second clutch member.

FIG. 4 is a longitudinal sectional view of an operation mechanism according to a second embodiment.

FIG. 5 is a longitudinal sectional view of an operation mechanism according to a third embodiment.

FIG. 6 is a plan view of a lock plate in an operation mechanism according to a third embodiment.

FIG. 7 shows a conventional blade mounting device.
FIG. 8 is a diagram in which FIG. 7 of 503382 is used.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Blade holding means, B ... Blade 21 ... Rod, 31 ... Operating rod, 41 ... Claw 60 ... Operating mechanism part 61 ... Operating member, 62 ... Rotating rod 70 ... Torque limiting means 71 ... First clutch member, 72 ... No. 2 Clutch member 80: Direct connection plate (direct connection means) 81: Direct connection plate of the second embodiment 83: Direct connection plate of the third embodiment

Claims (2)

(57) [Claims] 1. Up and down reciprocation at the front of the body housing
A rod, a blade holding means for attaching a blade to the rod, and a tip of the body housing.
A grip that is provided at the upper end and that is gripped during cutting work
While installing and removing the blade
Rotation operation to a blade attachment apparatus including operation members for operating the blade holding means, between said operating member and said blade holding means, the rotational torque of the blade mounting direction within a predetermined range A clutch that transmits and does not transmit rotational torque in the direction of blade removal
A torque limiting unit having a member , and separately rotating the operating member and the blade holding unit apart from the torque limiting unit.
And interposed directly means for directly Te, rotational torque for said blade holding means of said operating member
Rotation in the blade mounting direction
Transmission via torque limiting means while blade removal
The rotation in the direction does not go through the torque limiting
Blade mounting device for a reciprocating cutting tool is characterized in that a structure for transmitting through. 2. A blade holder for mounting a blade.
Operating the blade holding means by rotating the holding means.
Operating member for holding the operating member and the blade.
Between the holding means and the blade mounting direction.
Transmission within a certain range, rotating torque in the blade removal direction
Torque limiting means that does not transmit torque,
Is a separate blade attachment apparatus interposed directly means for direct connection therebetween, said torque limiting means, chromatic and first clutch member of said operating member, and a second clutch member of said blade holding means side The two clutch members are provided with mutually meshing clutch teeth on the surfaces facing each other, and the inclination angle of the surface of each clutch tooth that comes into contact when the blade is removed is made smaller than the inclination angle of the surface that comes into contact when the blade is attached. A blade mounting device for a reciprocating cutting tool, characterized in that a required rotational torque cannot be transmitted when the blade is removed.