JP6437796B2 - Caster to be installed on stepladder etc. - Google Patents

Description

  The present invention relates to a caster that is attached to a stepladder, chair, table, carriage, etc., and can move even if there is a slight level difference on the floor surface.

  FIG. 5 is a specific example showing a conventional general caster. The caster includes a wheel (b) and a curved frame (b), and the wheel (b) is supported by a shaft (c) provided at the lower end of the frame and is rotatable. The frame (b) has two curved support legs (d) and (d), and the wheel (b) is sandwiched between the two support legs (d) and (d). The frame (b) has a shaft (e) provided at its upper end rotatably mounted, and the wheel (b) can roll on the floor or the ground and rotate around the axis (e). The direction of the frame (b) can be changed.

That is, by providing an appropriate distance A between the ground contact point (e) of the wheel (b) and the rotating shaft (e) of the frame (b), the direction of the wheel (b) can be freely changed in the moving direction. I can do it.
The caster has casters attached at four locations on both the front and rear sides, but it has support legs that support the wheel (A) on a curved frame (B) as shown in the figure on either the front or rear side. A caster is installed. Therefore, the operator can move the carriage in an arbitrary direction by operating the handle.

  By the way, these casters are not limited to carts and can be prevented from being lifted when they are attached to a stepladder and moved. Heavy stepladders are difficult to carry when moving around, and are convenient if you can move them without lifting them. However, since a person steps on the stepladder, it is necessary to stabilize at a fixed position without moving when the person steps, and the caster for the stepladder has a function to lock the wheel so that it does not rotate. Is required.

The “caster attached to a stepladder” according to Japanese Patent Application Laid-Open No. 2008-13161 is provided with a highly secure locking function that does not rotate even slightly when a person works on the stepladder.
Therefore, the caster shown in FIG. 6 can rotate by supporting the wheels (g) and (g) on both sides of the frame (f), and the longitudinal main shaft ( H) is fitted so that it can rotate and slide, and a collar (re) is attached to the lower end of the vertical main shaft (H) that penetrates the vertical hole of the frame (F). A coil spring (n) provided on the upper surface of the frame urges and supports the longitudinal main shaft (h) and the leg (l), and if a person rests on the stepladder, the coil spring (n) compresses and deforms and is (Li) descends and touches the floor.

The wheel (g) and (g) do not rotate and move when the brim (li) lands on the floor. Therefore, even if the caster is attached to the lower end of the stepladder, the caster can be stably stopped at a predetermined place, and the steps can be safely raised.
By the way, if there is a step on the floor when moving the stepladder, the wheels (g) and (g) must get over the step, but if the height of the step is H or more, ) And the frame (f), the step cannot be overcome.

In the case of the caster of FIG. 6 as well, by providing an appropriate distance between the vertical main shaft (H) and the ground contact point of the wheel (G), the direction of the stepladder can be changed. Therefore, the wheel (g) is inevitably arranged behind the vertical main shaft (h), and the front of the frame (f) to which the vertical main shaft (h) fits greatly protrudes from the outer periphery of the wheel, and the front of the frame (f) Collides with the step.
“Casters to be mounted on a stepladder” according to Japanese Patent Application Laid-Open No. 2008-13161

  Thus, the conventional caster has the above-mentioned problems. The problem to be solved by the present invention is this problem, and it has a lock mechanism so that it can move over even if there is a step on the floor or the ground, and can stop at a predetermined place. Provide casters.

The caster according to the present invention pivotally supports the wheels on both sides of the frame, fits in a vertical hole penetrating the frame so that the vertical main shaft can rotate and slide, and penetrates the vertical hole of the frame. A collar is attached to the lower end of the vertical spindle. A coil spring is provided on the upper surface of the frame, and a spring force is applied to the leg by the coil spring to push it up. A lever that swings around the shaft is attached to the frame, and the wheel is supported by swinging the lever. It is possible to lift the shaft. That is, the flange can be positioned below the wheel by swinging the lever.
However, the caster targeted by the present invention may be configured without a wheel lifting mechanism.

The basic structure of a caster provided with a mechanism for moving the wheels up and down is the same as the “caster attached to a stepladder” according to Japanese Patent Application Laid-Open No. 2008-13161.
The caster of the present invention is in a position where the front of the frame does not protrude from the outer periphery of the wheel. By the way, if the lever pivoted on the frame is swung to lift the frame, the coil spring attached to the longitudinal main shaft is compressed, and a locking means is provided so that the lever is not pushed back by the compression spring force of the coil spring. I can do it.

  The caster according to the present invention is attached to the lower end of a leg such as a stepladder. Therefore, the caster wheel can be rolled to move the place without lifting the stepladder. Then, if a person is placed on the stepladder, the coil spring is compressed by the action of the weight, the vertical main shaft is lowered, the lower end abuts against the floor surface or the ground, and the stepladder is stabilized without moving. Furthermore, even if a person does not rest on the stepladder, the collar can be landed by operating the lever to lift the wheel and stop at a fixed position. Here, since the leg is on the same axis as the longitudinal main axis, the stability when a person is placed on the stepladder is increased.

  The caster of the present invention is arranged so that the front of the frame does not protrude from the outer periphery of the wheel, so that even if there are some steps on the floor or ground, the frame will not hit during movement, and the steps will be It is possible to get over. That is, it is not necessary to lift and move a heavy stepladder as in the conventional case when it reaches a step.

The Example which shows the caster which concerns on this invention. A caster in a moving state. A caster in a stationary state. A specific example of a guide groove provided with a locking piece so that the wheel shaft does not return. Conventional general caster. The other example which shows the conventional caster.

  FIG. 1 is an external view showing a caster according to the present invention, (a) is a side view, and (b) is a front view. In the figure, 1 is a wheel, 2 is a longitudinal main shaft, 3 is a frame, and 4 is a lever. The two wheels 1 and 1 are supported by both ends of a shaft provided on a frame 3 in the form of a block and can rotate. A hole is provided in the frame 3 in the vertical direction, and the vertical main shaft 2 passes through the hole, and the frame is allowed to rotate and slide around the vertical main shaft 2.

The vertical main shaft 2 is attached to the lower end of the leg 5 of the stepladder, so that the stepladder can move through the installation place via the caster. Here, the caster mounting structure is not particularly limited. For example, a hole is provided in the lower end of the leg 5 and a fitting shaft attached to the upper portion of the vertical main shaft 2 via a bearing can be fitted into the hole.
In the figure, the lower end of the leg is supported by a support washer 6 which is attached to the vertical main shaft 2 and functions as a bearing. A coil spring 7 is attached between the upper end of the frame 3 and the support washer 6.

The coil spring 7 is attached in a compressed state, and the leg 5 placed on the support washer 6 is lifted by the spring force of the coil spring 7. The vertical main shaft 2 fitted in the hole of the frame 3 is supported so as not to descend, and the flange 8 attached to the lower end of the vertical main shaft 2 is in contact with the lower end of the frame 3 through a bearing washer.
An appropriate distance is provided between the ground contact point of the wheel 1 and the center of the longitudinal main shaft. Therefore, the wheels 1 and 1 can be rotated with respect to the longitudinal main shaft 2 to change the direction during the movement, and the coil spring 7 Can be raised along the longitudinal main axis 2 by deformation.

  The wheels 1 and 1 are raised by compressing the coil spring 7, but the spring force of the coil spring 7 always acts on the frame 3 to push the wheels 1 and 1 downward below the longitudinal main shaft 2. Therefore, the outer peripheral lower end (grounding point) of the wheels 1 and 1 is located below the brim 8 provided at the lower end of the vertical main shaft 2, and the brim 8 does not contact the floor surface and the ground when moving.

  However, when a person is placed on the stepladder, the weight acts on the leg 5 to compress the coil spring 7 and push down the longitudinal main shaft 2. The flange 8 provided at the lower end is in contact with the floor surface. Of course, although the wheels 1 and 1 are also in contact with the floor surface, the wheels 1 and 1 stop at a fixed position without rolling when the brim 8 hits the floor surface. That is, if the caster of the present invention is attached to the leg 5 of the stepladder, the stepladder can roll the wheels 1 and 1 to move to an arbitrary place. Stabilizes in contact with the floor.

On the other hand, a lever 4 is attached to the caster of the present invention, and the stepladder can be stopped at a fixed position by operating the lever 4.
2 and 3 show the operation of the lever 4, and the lever 4 is attached so as to be swingable about a shaft 9 provided in the frame 3. The lever 4 is a member obtained by punching a metal plate, and has both side plates 10, 10, and the both side plates 10, 10 are pivotally supported by the frame 3 with the frame 3 sandwiched therebetween. I can do it. The side plates 10 and 10 have contact sides 11 and 12 adjacent to each other. The ends of the side plates 10 and 10 are connected by a shaft 13, and a roller 14 is attached to the shaft 13.

  By the way, the state shown in FIG. 2 is a case where the vertical main shaft 2 is raised (when the wheels 1 and 1 are lowered), and the flange 8 at the lower end of the vertical main shaft 2 is not in contact with the floor surface. The wheel 1 is grounded, and the wheel 1 can rotate when moving. That is, the coil spring 7 extends, and the longitudinal main shaft 2 is lifted and the presser plate 15 attached to the flange 8 is in contact with the contact side 11 formed on the side plate 10 of the lever 4. If a person rests on the stepladder in this state and the weight is applied to the vertical main shaft 2 and descends, the flange 8 at the lower end of the vertical main shaft 2 can come into contact with the floor surface, and the wheel 1 cannot roll.

On the other hand, FIG. 3 shows a case where the roller 14 attached to the tip of the lever 4 is swung with a foot, and the contact side 12 of the side plate 10 presses the holding plate 15. As a result, the wheels 1 and 1 are raised, the flange 8 at the lower end of the vertical main shaft 2 is in contact with the floor surface, and the stepladder can be stopped at a fixed position without moving. Here, the distance L ₁ between the shaft 9 supporting the lever 4 and the contact side 11 is smaller than the distance L ₂ between the shaft 9 and the contact side 12, and the contact side 12 hits the holding plate 15. 1 rises and the brim 8 comes into contact with the floor.

In this case, the coil spring 7 interposed between the frame 3 and the support washer is compressed. Therefore, by operating the lever 4 and swinging, the flange 8 attached to the lower end of the vertical main shaft 2 can come into contact with the floor surface and the stepladder can be stopped, so that it is stored in a fixed position at one corner of the storeroom or the room. It becomes possible. When using a stepladder, if the roller 14 of the lever 4 is lifted back to the state shown in FIG. 2, the frame 3 is pushed down by the spring force of the coil spring 7, the wheels 1 and 1 are grounded, and the collar 8 is Move away from the floor.
By the way, the lever shape shown in FIG. 2 and FIG. 3 is only one specific example, and other lever shapes are free.

  Incidentally, in the caster of the present invention, as shown in FIG. 2, the front surface 16 of the frame 3 is retracted from the outer periphery 17 of the wheel 1. Therefore, when the caster moves on the floor surface or the ground, when there is a step on the floor surface or the ground, the front 16 of the frame 3 does not hit the step. The wheel outer periphery can always get over the bump. When the front of the frame protrudes forward from the outer periphery of the wheel as in the prior art, the frame cannot collide with the step and cannot ride up.

  Then, when the wheel 1 is arranged in front of the conventional caster and the lever 4 swings and the wheel 1 is lifted as shown in FIG. 3, the spring force of the compressed coil spring 7 causes the state shown in FIG. It will be returned to. Therefore, in the present invention, the locking piece 20 is provided in the guide groove 19 in which the shaft 18 of the wheel 1 moves. FIG. 4 is an enlarged view of the guide groove 19, and a locking piece 20 is provided along the guide groove 19 curved in an arc shape around the shaft 9.

The locking piece 20 is an elongated member along the guide groove 19 and can be bent and deformed, and the tip 21 is locked to the shaft 18. Therefore, the shaft 18 that has moved to the tip of the guide groove 19 cannot be returned backward only by the spring force of the coil spring 7 by being locked to the tip of the locking piece 20 and can be stopped at the tip of the guide groove 19. .
Here, the locking means for fixing the shaft 18 is not limited to the case shown in FIG. 4 and may be configured without using the locking means.
By the way, although the caster provided with the locking mechanism has been described in the embodiment, the caster of the present invention is also intended for the case where the locking mechanism is not provided.

1 Wheel 2 Vertical Spindle 3 Frame 4 Lever 5 Leg 6 Support Washer 7 Coil Spring 8 Head 9 Axis
10 Side plate
11 per side
12 per side
13 axes
14 Laura
15 Presser plate
16 Front
17 circumference
18 axes
19 Guide groove
20 Locking piece
21 Tip

Claims (2)

In casters attached to the lower legs of legs such as stepladders, chairs, tables, and carts, wheels can be pivotally supported on both sides of the frame, and the vertical main shaft can be rotated and slid in a vertical hole that penetrates the frame. A flange is attached to the lower end of the vertical main shaft that passes through the vertical hole of the frame, and a spring is applied to the leg by a coil spring provided on the upper surface of the frame, so that the lever can swing on the frame. installed, abuts a contact edge formed on the lever collar, configured to lever can Rukoto lift the wheel by abutment of the flange to another per side by swinging the and lift the wheel In this case, if a guide groove is formed on the side plate in which the wheel shaft moves as the lever swings so that the lever does not return backward by the spring force of the compressed coil spring. In, the locking piece provided in the guide groove, the tip of the engaging piece when the shaft the wheel is lifted is positioned at an end portion of the guide groove so as to engage the shaft, further the frame front wheel periphery A caster characterized in that it does not protrude beyond. The caster according to claim 1, wherein a press plate is attached to the collar, and a contact side of the lever is brought into contact with the press plate.

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