JP2008143204A - Caster - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a caster which can realize a carriage, etc. capable of being moved by a furthermore small force, and can prevent the generation of the breakage of a tire, etc. <P>SOLUTION: The caster 1 comprises a wheel portion 22 capable of rotating about an axle 10, a tire 24 to be fitted on the outer circumferential portion of the wheel portion 22, a supporting member 30 for supporting the axle 10, and a mounting plate 40 for swivellably holding the supporting member 30 so as to swivel in a plane parallel with the axle 10, wherein two wheels 20, which are composed of the wheel portion 22 and the tire 24 and have the same diameter D, are coaxially held by the axle 10, and can independently rotate respectively. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a caster used for a cart or the like.

2. Description of the Related Art Conventionally, at manufacturing sites such as vehicle manufacturing factories, various relatively heavy parts are placed on a cart and pulled. In this case, the total weight of the parts placed on the carriage may be, for example, 100 [kg] or more, and casters having a large load resistance are used for the wheels of the carriage.
For example, in the prior art described in Patent Document 1, a vehicle with a brake caster including a caster having a mechanism for locking wheels has been proposed.
For example, in the prior art described in Patent Document 2, there is proposed a transport cart that includes a caster and can be reduced in size when not in use.
JP 2004-131001 A JP 2002-0697965 A

In the prior art described in Patent Document 1 and Patent Document 2, the casters provided at the four corners of the carriage are provided with tires that are enlarged and widened according to the load resistance.
In particular, in the case of a wide tire, since the contact area becomes large, a relatively large force is required when moving the carriage by towing or the like. In addition, carts often turn around corners with relatively small radii, and in the case of wide tires, when turning corners, the rotation difference between the inside and outside of the tire itself increases, requiring a relatively large force. And
In general, non-hollow tires (tires filled with tire materials) are used on the outer periphery of the wheels of the casters, and they are repeatedly deformed and restored according to the load. Chipping or the like may occur.
The present invention has been developed in view of the above points, and provides a caster that can realize a cart that can be moved with a smaller force and can prevent occurrence of tire chipping or the like. This is the issue.

As means for solving the above-mentioned problems, the first invention of the present invention is a caster as described in claim 1.
The caster according to claim 1 includes a wheel portion rotatable around an axle, a tire fitted in an outer peripheral portion of the wheel portion, a support member supporting the axle, and a plane parallel to the axle. A caster having a mounting plate for holding the support member so as to be pivotable, wherein two wheels having the same diameter constituted by the wheel portion and the tire are coaxially held by the axle. Each of the wheels is rotatable independently of each other.

Moreover, 2nd invention of this invention is a caster as described in Claim 2.
The caster according to claim 2 includes a wheel portion rotatable around an axle, a tire fitted into an outer peripheral portion of the wheel portion, a support member supporting the axle, and a plane parallel to the axle. A mounting plate for holding the support member in a pivotable manner, wherein the tire is formed in a non-hollow shape with an elastic body that is deformed and restored in accordance with a load, and the tire has a radial direction. A plurality of relief grooves are formed on the side surface of the tire along which the flank of the deformed portion deformed by a load is formed.

Moreover, the 3rd invention of this invention is a caster as described in Claim 3.
The caster according to claim 3 is the caster according to claim 2, wherein each of the relief grooves is formed to have a predetermined angle with respect to a direction from the outer peripheral portion of the tire toward the center. .

According to the caster of the first aspect, the wheels of the caster are constituted by two tires having a relatively narrow width. Since it has two wheel parts with respect to a wide conventional caster having one wheel part, the strength of the wheel part is equal to or higher than that of the conventional caster. Further, since the ground contact area of the tire is small, the rolling resistance is also small, and when this caster is used for a carriage or the like, it can be moved with a smaller force.
In addition, since the two wheels are coaxial and can rotate independently, when this caster is used for a carriage, etc., when turning a corner, in addition to the narrow width of each wheel, the inner side Since the outer wheel and the outer wheel can rotate at different rotational speeds, it is possible to turn at a corner having a small radius with a smaller force.

  Further, according to the caster according to the second aspect, the load per unit area at the contact portion of the tire increases as the contact area becomes smaller, the deformation amount of the tire becomes relatively large, and cracks and cracks occur. May occur. However, by forming a clearance groove on the side surface of the tire and providing a place where the deformed portion can escape appropriately, it is possible to appropriately prevent the tire from cracking or chipping.

  Moreover, according to the caster of Claim 3, a crack and a chip | tip of a tire can be prevented more appropriately.

  The best mode for carrying out the present invention will be described below with reference to the drawings. FIG. 1 shows a schematic external view (perspective view) in an embodiment of a caster 1 of the present invention. FIG. 2 shows an example of a front view of the caster 1. In each figure, the X axis, Y axis, and Z axis are orthogonal to each other, the X axis and Y axis indicate the horizontal direction, and the Z axis indicates the vertical direction.

● [Appearance and configuration of caster 1 (Figs. 1 and 2)]
The caster 1 of the present invention includes an axle 10 having a horizontal axis HJ as a rotation axis, a wheel portion 22 rotatable around the axle 10, a tire 24 fitted to the outer periphery of the wheel portion 22, and the axle 10. A support member 30 to be supported, and a mounting plate 40 that rotatably holds the support member 30 in a plane parallel to the axle 10 (in the XY plane in the example of FIG. 1). The support member 30 can be swung about the vertical axis VJ as a rotation axis, and is held by the mounting plate 40 via the swivel shaft 42 and the bearing portion 50 (see FIG. 2).
The caster 1 is provided with two wheels 20 constituted by a wheel portion 22 and a tire 24 on the axle 10 coaxially. Moreover, the diameter D of the two wheels 20 is the same. The two wheels 20 provided on the same axis can rotate independently of each other.

A conventional caster (a caster having a relatively large load resistance) is composed of a single wheel having a tire having a width W and a wheel portion in FIG. 2, and thus has a larger ground contact area than the caster 1 shown in FIG. Because of its wide width), the rolling resistance and the rotation difference between the inside and outside during corner turning were large. For this reason, a relatively large force is required both when the cart with the conventional caster is moved linearly and when cornering.
However, in the caster 1 shown in FIG. 2, the width of the tire 24 with respect to the width W is width WL + width WR, which is smaller than the width W (width WL + width WR <width W), and the ground contact area is small. 2 is small, when the carriage to which the caster 1 shown in FIG. 2 is attached is moved linearly, it can be moved with a smaller force than in the prior art.
Further, since the width WL and the width WR of the tires 24 of the two wheels 20 are much smaller than the tire width W of the conventional casters (width WL <width W, width WR <width W), corner turning , The rotation difference between the inside and the outside of each tire 24 is reduced, and the resistance due to the rotation difference is reduced. Moreover, since each wheel 20 can rotate at a different rotational speed, the inner wheel 20 and the outer wheel 20 can rotate at appropriate rotational speeds according to the corner radius. For this reason, the resistance at the time of corner turning is significantly reduced as compared with the conventional case, and even a corner having a small radius can be turned with a small force.

  In addition, since the wheel portion 22 is formed of one or two disk-shaped members, the conventional wheel has two wheels rather than one caster of the present embodiment. It has higher strength. For this reason, about the wheel part 22, it has a load bearing characteristic more than the conventional caster.

[[Configuration to prevent tire chipping of tire 24 with increasing load (FIG. 3)]
However, the load per unit area of the tire increases as the tire width becomes narrower than before.
The tire 24 described in the present embodiment is not a hollow tire but a non-hollow tire (a tire filled with a tire material member up to the inside). The tire 24 is formed of an elastic body (hard rubber or the like), and a portion of the tire 24 that rotates and contacts the ground is compressed and deformed (when a load is applied). When it leaves (removes the load), it recovers (the tire 24 is formed of an elastic body that deforms and recovers according to the load).
In a normal tire, when a load of a predetermined load or more is applied, a crack, a tire chip, or the like occurs due to a difference in shape between a deformed portion deformed according to the load and a portion where no load is applied (FIG. 3A ) See section 24A).
Therefore, in the caster 1 described in the present embodiment, as shown in FIG. 3 (B), by forming a relief groove M on the tire side surface along the radial direction of the tire 24, cracks, tire chipping, and the like are caused. It can be prevented appropriately. The escape groove M does not have to be formed on the ground contact surface of the tire 24, but may be formed on the tire side surface.

In the case of the caster 1 in which the diameter D of the wheel 20 is about 200 [mm], and the widths WL and WR of the tires 24 are about 30 [mm], the inventor has a groove width H of about 3 [mm] and a groove depth. A good result was obtained by forming the relief groove M with a V groove having an F of about 3 [mm]. The shape of the escape groove M is not limited to the V groove, and may be formed in various shapes such as a U groove, and is configured so as to form a space as a escape place of the deformed portion of the tire 24 deformed by a load. It only has to be done.
Further, in the example of FIG. 3B, the relief groove M is formed in a straight line having a constant width. However, the relief groove M may not be particularly straight, and the width of the portion where the width is not constant and the deformation amount is increased. You may make it enlarge locally.
Further, in the above case, the inventor obtained a good result when the angle (relief groove inclination angle θ) formed by the direction from the outer peripheral portion of the tire 24 toward the tire center P and the relief groove M is a predetermined angle. It was confirmed that it was obtained. In the above case, better results were obtained when the relief groove inclination angle θ was 45 °.
In addition, the above confirmation was made with the gap K of the escape groove M being about 45 [mm].
Note that the dimensions (width, depth, etc.) of the escape groove M, the interval to be formed, and the like can be appropriately determined according to the material of the tire 24, the load-bearing weight, the diameter and width of the tire 24, and the like.

The caster 1 of the present invention is not limited to the appearance, configuration, dimensions and the like described in the present embodiment, and various modifications, additions, and deletions can be made without changing the gist of the present invention.
The numerical values used in the description of the present embodiment are examples, and are not limited to these numerical values.
In the description of the present embodiment, the caster 1 is provided with two wheels 20 having the same diameter on the same axis. However, the caster 1 may be provided with three or more wheels having the same diameter on the same axis. .
The caster 1 described in the present embodiment is not limited to the application provided at the four corners of the carriage, and can be used as wheels of various devices.

It is a figure explaining the outline appearance figure (perspective view) of one embodiment of caster. It is a figure explaining the schematic external view (front view) of one embodiment of caster. FIG. 4 is a diagram illustrating a clearance groove M provided on a side surface of a tire 24.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Caster 10 Axle 20 Wheel 22 Wheel part 24 Tire 30 Support member 40 Mounting plate 42 Turning axis 50 Bearing part D Wheel diameter M Relief groove

Claims (3)

A wheel part rotatable around the axle,
A tire fitted into the outer periphery of the wheel part;
A support member for supporting the axle;
A mounting plate that rotatably holds the support member in a plane parallel to the axle;
A caster equipped with
Two wheels having the same diameter constituted by the wheel portion and the tire are coaxially held by the axle, and the wheels can rotate independently of each other.
Casters characterized by that. A wheel part rotatable around the axle,
A tire fitted into the outer periphery of the wheel part;
A support member for supporting the axle;
A mounting plate that rotatably holds the support member in a plane parallel to the axle;
A caster equipped with
The tire is formed in a non-hollow shape with an elastic body that deforms and recovers according to a load,
On the tire side surface along the radial direction of the tire, a plurality of escape grooves serving as escape places for the deformed portion deformed by a load are formed.
Casters characterized by that. The caster according to claim 2,
Each of the escape grooves is formed to have a predetermined angle with respect to the direction from the outer peripheral portion of the tire toward the center.
Casters characterized by that.

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