JP2004058983A - Caster and wheel supporting structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a caster for absorbing shock by a simple structure without increasing the size thereof, and performing effective shock absorption in an arbitrary direction perpendicular to the axis of rotation. <P>SOLUTION: The caster comprises an upper face 12 screwed to a body to be supported by using a hole 11, a bracket 1 having two suspended shaft supporting parts 13 provided downwardly with an interval from the upper face 12, a shaft 2 stretched between the shaft supporting parts 13 below the bracket 1, an elastic member 3 such as a coil spring provided on the circumference of the shaft 2, and a wheel 4 with an inner circumferential surface supported by the elastic member 3. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention mainly relates to a buffer mechanism of a caster.
[0002]
[Prior art]
As a conventional caster provided with a shock absorbing mechanism, a caster in which a spring is provided between an axle support member that supports an axle and a top plate that supports a supported body is known (for example, Japanese Patent Application Laid-Open No. 7-329505).
There is also known a caster in which a link that supports an axle is pivotably supported on a frame and a hydraulic damper that expands and contracts as the link pivots with respect to the frame.
Prior art document information related to the invention of this application includes the following.
[0003]
[Patent Document 1]
JP-A-7-329505
[Patent Document 2]
JP-A-200-18647 [0005]
[Problems to be solved by the invention]
According to each of the above-mentioned conventional techniques, since the buffer mechanism is configured as described above, it is inevitable that the caster is increased in size by providing the buffer mechanism. Further, since the structure is relatively complicated and the number of parts is large, various costs for manufacturing the casters are greatly increased. Further, the buffering action mainly works only in the vertical direction, and it is not always possible to achieve a sufficient buffering effect against impacts in other directions such as the front-back direction.
[0006]
Therefore, an object of the present invention is to provide a caster that realizes buffering with a simple structure without increasing the size of the caster. Another object of the present invention is to provide a caster that performs more effective cushioning in an arbitrary direction perpendicular to the rotation axis.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a bracket, a shaft bridged over the bracket, an elastic member having elasticity provided around the shaft, and the elastic member having a central hole into which the elastic member is inserted. A caster having a supported wheel portion.
[0008]
According to such a caster, buffering can be realized with a simple structure in which an elastic member is provided between the wheel portion and the shaft, and the elastic member can be accommodated between the wheel portion and the shaft. By doing so, the caster can be prevented from being enlarged. Further, according to such a caster, the cushioning can be similarly performed not only in the vertical direction but also in any direction perpendicular to the rotation axis by the elastic action of the elastic member.
[0009]
Here, as such an elastic member, a coil spring wound so as to form a first portion having a relatively small diameter and a second portion having a relatively large diameter can be used. In this case, such a coil spring is configured such that the inner peripheral side surface of the first portion is supported by the shaft, and the outer peripheral side surface of the second portion supports the wall surface of the central hole of the wheel portion. Attach to Such a coil spring is inexpensive and can be easily manufactured, and it is relatively easy to obtain elasticity suitable for the use of the caster and to reduce deterioration over time.
[0010]
In this case, it is also preferable to cover the coil spring with a covering tube. In addition, it is preferable that a cover is provided to cover the center hole of the wheel portion with the arithmetic member stored in the center hole.
By providing such a structure, a more stable and smooth operation can be realized.
Now, in the caster as described above, the shaft supported by the supported member, the elastic member having elasticity provided around the shaft, and the elastic member having a central hole into which the elastic member is inserted are supported. The structure having the wheel portion can be applied as a wheel support structure in any application other than casters.
[0011]
Now, in order to achieve the above object, the present invention further includes a hollow cylindrical bearing portion fixed to a supported member, a wheel portion having an inner peripheral side surface, and an elastic member, wherein the elastic member Is a coil spring wound to form a first portion having a relatively small diameter and a second portion having a relatively large diameter, wherein the first portion is inserted into the bearing portion. The outer peripheral side surface of the first portion is supported by the inner peripheral side surface of the bearing portion, and the outer peripheral side surface of the second portion supports the inner peripheral side surface of the wheel portion. A wheel support structure is also provided.
[0012]
According to such a wheel support structure, when the wheel portion is mounted in a cantilever manner, it is possible to realize cushioning with a simple and compact structure in which the wheel portion is mounted on the bearing portion via the elastic member. Further, the cushioning can be similarly performed not only in the vertical direction but also in any direction perpendicular to the rotation axis by the elastic action of the elastic member.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described.
First, a first embodiment will be described.
1 and 2 show the structure of the caster according to the first embodiment.
In the figure, a is a front view of the caster, b is a left side view of the caster, c is a top view of the caster, and d is a bottom view of the caster. The back of the caster appears symmetrically with the front of the caster, and the right side of the caster appears symmetrically with the left side. In addition, e in the drawing is a cross-sectional view taken along a cutting line AA shown in b in the drawing, and FIG. 2 shows a procedure of assembling each component of the caster.
[0014]
As shown in the drawing, the caster includes a bracket 1, a shaft 2, an elastic member 3, wheels 4, and a wheel cover 5. The bracket 1 has an upper surface 12 that is screwed to a supported body using a hole 11 and two shaft support portions 13 that are vertically spaced below the upper surface 12 with a gap therebetween. It is installed between the shaft support portions 13 below the bracket 1. The elastic member 3 is provided around the shaft 2, and the wheel 4 has an inner peripheral surface supported by the elastic member 3.
[0015]
Here, the shaft 2 is, for example, a bolt and a nut, and is fixed so as not to rotate with respect to the shaft support portion 13. However, the shaft 2 may be pivotally supported by the shaft support 13 so as to be rotatable.
Next, as shown in FIG. 3A, the elastic member 3 reduces the diameters of both end portions 301 and 302 so that the diameter of the inner peripheral side surface is substantially equal to the diameter of the shaft 2, and the central portion 303 The coil spring 30 includes a coil spring 30 having a relatively large diameter such that the diameter of the outer peripheral side surface is substantially equal to the diameter of the inner peripheral side surface of the wheel 4, and a coating tube 31 that covers the coil spring. Here, as such a coated tube, a heat-shrinkable tube having low friction can be used. However, the covering tube does not necessarily have to be provided.
[0016]
The elastic member 3 is not fixed to the shaft 2 because only the inner peripheral side surfaces of the both end portions 301 and 302 are supported by the penetrated shaft 2. Further, the central portion 303 supporting the wheel 4 from the inside on the outer peripheral side surface is not fixed to the wheel 4.
[0017]
The wheel cover 5 is provided to prevent the elastic member 3 from jumping out or moving to the left and right, and is fixed to the shaft 2. However, the wheel cover 5 may be fixed to the wheel 4 and rotate with the wheel 4.
In such a structure, the elastic member 3 is rotatable with respect to the shaft 2 and does not hinder the rotation of the wheel 4 with respect to the shaft 2. When an impact or pressure is applied to the wheel or the bracket 1, the elastic member 3 elastically deforms so that the central portion moves in the direction in which the force is applied, as schematically shown in FIG. Here, this buffering action similarly acts in an arbitrary direction perpendicular to the rotation axis of the wheel 4.
[0018]
As above, the first embodiment of the present invention has been described.
By the way, as the elastic member 3 in the first embodiment, an elastic body other than the coil spring shown in FIG. 3A may be used.
For example, as the elastic member 3, a spring in which a metal plate as shown in FIG. 3C is spirally wound and covered with a covering tube may be used. However, the covering tube does not necessarily have to be provided.
As shown in FIGS. 3D and 3E, the elastic member 3 is connected to an elastic body 33 such as rubber, which is a hollow cylinder, a hollow shaft 34 penetrating the elastic body, and a shaft 34 with the elastic body interposed therebetween. It is also possible to use a member constituted by a member having the two holding plate portions 35 and 36 thus formed. In addition, the pressing plate portion functions to suppress excessive deformation of the elastic body and to increase the elastic constant of the elastic body in the direction perpendicular to the axis of the shaft 2, and the hollow shaft connects the elastic member 3 to the shaft 2. On the other hand, it works to enable smooth rotation.
[0019]
Further, as shown in FIG. 3f, the elastic member 3 is made of a metal plate such that it has a conical shape at both ends and a cylindrical shape at the center, and has a shaft through hole at the center of both ends. It is also possible to use a plate spring formed by processing and covered with a coating tube. The leaf spring shown in FIG. 3G can be manufactured by, for example, pressing a metal plate having a shape as shown in FIG. 3F. However, the covering tube does not necessarily have to be provided.
As the elastic member 3, as shown in FIG. 3h, a member in which the coil spring 300 is embedded in a soft material 310 such as a synthetic rubber or a synthetic resin having a hole for penetrating the shaft by insert molding or the like is used. You can also.
[0020]
Further, in the above embodiment, the wheels 4 with bearings may be used as the wheels 4. That is, as shown in FIG. 1f, the side surface is shown, and FIG. 1g is a sectional view taken along a cutting line BB in FIG. 1f. A bearing 43 provided between the outer ring portion 42 and the inner ring portion 41 may be used. By doing so, the wheels 4 can be rotated more smoothly.
[0021]
Further, in the above embodiment, the shaft 2 is rotatably supported by the shaft support 13 without fixing the shaft 2 to the shaft support 13 and using or not using bearings or the like. Alternatively, the elastic member 3 may be pivotally supported by the shaft 2 via a bearing.
[0022]
Note that the above-described structure for mounting the wheel 4 using the shaft 2 and the elastic member 3 can be similarly applied as a mounting structure for the wheel 4 in an arbitrary device other than the casters.
Hereinafter, a second embodiment of the present invention will be described.
The second embodiment relates to an application to an apparatus such as a vacuum cleaner having wheels 4 on the left and right as shown in the front view of FIG. 4a, the side view of FIG. 4b, and the top view of FIG. 4c. is there.
As shown in FIG. 4d, which is a cross-section taken along the line CC in FIG. 4b, the mounting structure of the wheel 4 in the present device comprises a device main body 6 having a hollow cylindrical bearing protruding in the lateral direction, and an elastic member 7 And wheels 8. The shaft 81 of the wheel 8 is inserted into the bearing 61 of the device body 6, and the hook 82 provided at the tip of the shaft 81 is locked by the locking portion 62 of the bearing. 4D, the elastic member 7 has the diameter of the one end portion 711 as shown in FIG. 4D, and the diameter of the outer peripheral side surface is the same as that of the inner peripheral side surface of the bearing portion 61. A coil spring 71 in which the diameter is relatively small so as to be substantially equal to the diameter and the diameter of the other end portion 712 is relatively large so as to be substantially equal to the diameter of the inner peripheral side surface of the wheel 4; And a covering tube 72 for covering the above. However, the covering tube 72 does not necessarily have to be provided.
[0023]
Now, the elastic member 7 has a smaller diameter portion 711 inserted into the bearing portion 61 and its outer peripheral side surface is only supported by the inner peripheral side surface of the bearing portion 61. Not fixed. Also, the larger diameter portion 712 of the elastic member 7 that supports the wheel 8 from the inside to the outer peripheral side surface is not fixed to the wheel 8.
[0024]
In such a structure, the elastic member 7 is rotatable with respect to the bearing 61 and does not hinder the rotation of the wheel 8 with respect to the bearing 61. Further, when an impact or pressure is applied to the wheel or the apparatus main body 6, the elastic member 7 elastically deforms so as to move the portion 712 having a larger diameter in the direction in which the force is applied, and buffers the portion. Here, this buffering action similarly acts in an arbitrary direction perpendicular to the rotation axis of the wheel 4.
[0025]
As described above, the second embodiment of the present invention has been described. Note that the mounting structure of the wheel 4 shown in the second embodiment can be similarly applied as the mounting structure of the wheel 4 in an arbitrary device. For example, the present invention can also be applied as a mounting structure for a twin wheel caster.
[0026]
【The invention's effect】
As described above, according to the present invention, it is possible to provide a caster that realizes buffering with a simple structure without increasing the size of the caster. Further, it is possible to provide a caster that performs more effective cushioning in an arbitrary direction perpendicular to the rotation axis of the wheel.
[Brief description of the drawings]
FIG. 1 is a diagram showing a structure of a caster according to a first embodiment of the present invention.
FIG. 2 is a diagram illustrating a structure of a caster according to the first embodiment of the present invention.
FIG. 3 is a view showing an elastic member according to the first embodiment of the present invention.
FIG. 4 is a view showing a structure of a caster according to a second embodiment of the present invention.
[Explanation of symbols]
1: Bracket, 2: Shaft, 3: Elastic member, 4: Wheel, 5: Wheel cover, 6: Device body, 7: Elastic member, 8: Wheel, 11: Hole, 12: Top surface, 13: Shaft support, 30: Coil spring, 31: Coated tube, 41: Inner ring, 42: Outer ring, 43: Bearing, 61: Bearing, 71: Coil spring, 72: Coated tube, 81: Shaft.

Claims (6)

A bracket, a shaft provided on the bracket, an elastic member having elasticity provided around the shaft, and a wheel portion supported by the elastic member having a central hole into which the elastic member is inserted. A caster that features. The caster according to claim 1,
The elastic member is a coil spring wound so as to form a first portion having a relatively small diameter and a second portion having a relatively large diameter, and the inner peripheral side of the first portion. A caster, wherein a side surface is supported by the shaft, and an outer peripheral side surface of the second portion supports a wall surface of a center hole of the wheel portion. The caster according to claim 2,
The caster, wherein the elastic member includes a covering tube covering the coil spring. The caster according to claim 1, 2, or 3,
A caster having a cover for covering a center hole of the wheel portion with the elastic member housed in the center hole. A shaft provided on the supported member, an elastic member having elasticity provided around the shaft, and a wheel portion supported by the elastic member having a central hole into which the elastic member is inserted. Wheel support structure. A hollow cylindrical bearing fixed to the supported member, a wheel having an inner peripheral side surface, and an elastic member,
The resilient member is a coil spring wound to form a first portion having a relatively small diameter and a second portion having a relatively large diameter, wherein the first portion is the bearing portion. And the outer peripheral side surface of the first portion is supported by the inner peripheral side surface of the bearing portion, and the outer peripheral side surface of the second portion supports the inner peripheral side surface of the wheel portion. A wheel support structure characterized by the following.

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