JP3689691B2 - Casters and wheel support structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention mainly relates to a buffering mechanism for casters.
[0002]
[Prior art]
As a conventional caster provided with a buffer 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, JP-A-7-329505).
A caster is also known in which a link supporting an axle is pivotally supported on a frame so as to be provided with a hydraulic damper that expands and contracts as the link swings with respect to the frame.
Prior art document information relating to the invention of this application includes the following.
[0003]
[Patent Document 1]
JP-A-7-329505
[Patent Document 2]
Japanese Patent Laid-Open No. 200-18647
[Problems to be solved by the invention]
According to each of the conventional techniques, since the buffer mechanism is configured as described above, it is inevitable that the caster becomes large due to the buffer mechanism. In addition, since the structure is relatively complicated and the number of parts is large, the increase in various costs for caster production is also large. 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-rear 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. In addition, another object of the present invention is to provide a caster that performs more effective buffering in an arbitrary direction perpendicular to the rotation axis.
[0007]
[Means for Solving the Problems]
To achieve the above object, the present invention provides a bracket, a shaft erected on the bracket, an elastic member having elasticity around the shaft, and an elastic member having a central hole in which the elastic member is inserted. There is provided 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, it is possible to prevent the casters from becoming large. Further, according to such a caster, it is possible to similarly buffer not only in the vertical direction but also in an arbitrary 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, the 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 can be manufactured inexpensively and easily, and it is relatively easy to obtain elasticity suitable for caster applications and to reduce deterioration over time.
[0010]
In this case, it is also preferable to cover the coil spring with a covering tube. It is also desirable to provide a cover that covers the central hole of the wheel portion in a state where the arithmetic member is housed in the central hole.
By providing such a structure, a more stable and smooth operation can be realized.
In the caster as described above, the caster was supported by the shaft spanned on the supported body, the elastic member having elasticity around the shaft, and the elastic member having the central hole into which the elastic member was inserted. The structure having the wheel portion can also be applied as a wheel support structure in any application other than casters.
[0011]
In order to achieve the object, the present invention further includes a hollow cylindrical bearing portion fixed to a supported body, a wheel portion having an inner peripheral side surface, and an elastic member, and 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 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 attached in a cantilever manner, the buffer can be realized with a simple and compact structure in which the wheel portion is attached to the bearing portion via the elastic member. Further, the buffering can be similarly performed not only in the vertical direction but also in an arbitrary direction perpendicular to the rotation axis by the elastic action of the elastic member.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described.
First, the first embodiment will be described.
1 and 2 show the structure of a 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 the cutting line AA shown in b in the drawing, and FIG. 2 shows a procedure for assembling each part of the caster.
[0014]
As shown in the figure, the caster includes a bracket 1, a shaft 2, an elastic member 3, a wheel 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 suspended below the upper surface 12 with a space between each other. 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 inner surface of the wheel 4 is 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 portion 13 so as to be rotatable.
Next, as shown in FIG. 3 a, the elastic member 3 is formed such that the diameters of both end portions 301 and 302 are relatively small so that the diameter of the inner peripheral side surface is substantially equal to the diameter of the shaft 2. The coil spring 30 has a relatively large diameter so 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 covering tube 31 that covers the coil spring. Here, as such a coated tube, a low-friction heat-shrinkable tube or the like can be used. However, the covering tube is not necessarily provided.
[0016]
The elastic member 3 is not fixed to the shaft 2 except that the inner peripheral side surfaces of both end portions 301 and 302 are supported by the penetrating shaft 2. Further, the central portion 303 that supports the wheel 4 from the inner side to 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 and 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 rotated together 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. Further, when an impact or pressure is applied to the wheel or bracket 1, the elastic member 3 is elastically deformed so as to move in the direction in which the center is applied as shown in FIG. Here, this buffering action similarly acts in an arbitrary direction perpendicular to the rotation axis of the wheel 4.
[0018]
The first embodiment of the present invention has been described above.
By the way, as the elastic member 3 in the first embodiment described above, 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 wound in a spiral shape and covered with a covering tube may be used. However, the covering tube is not necessarily provided.
As shown in FIGS. 3d and 3e, the elastic member 3 is connected by an elastic body 33 on a hollow cylinder such as rubber, 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 two pressed plate portions 35 and 36. The holding plate portion suppresses excessive deformation of the elastic body and functions to increase the elastic constant in a direction perpendicular to the axis of the shaft 2 of the elastic body. The hollow shaft causes the elastic member 3 to be attached to the shaft 2. In contrast, it works to enable smooth rotation.
[0019]
Further, as shown in FIG. 3f, the elastic member 3 is a metal plate having a conical shape at both ends and a cylindrical shape at the center, and a hole for penetrating the shaft at the center of both ends. It is also possible to use a leaf spring formed by processing and covered with a covering 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 is not necessarily provided.
Further, 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 cylindrical 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]
In the above embodiment, the wheel 4 with a bearing may be used as the wheel 4. That is, as shown in FIG. 1f, a side view, and FIG. 1g, a cross-sectional view taken along the cutting line BB in FIG. It is also possible to use a bearing 43 provided between the outer ring portion 42 and the outer ring portion 42 that rotates around the inner ring portion 41 as an axis. By doing in this way, the wheel 4 can be rotated more smoothly.
[0021]
In the above embodiment, the shaft 2 is pivotally supported by the shaft support portion 13 with or without using a bearing or the like without fixing the shaft 2 to the shaft support portion 13. The elastic member 3 may be pivotally supported by the shaft 2 via a bearing.
[0022]
In addition, the structure which attaches the wheel 4 using the above shaft 2 and the elastic member 3 can also be applied similarly as an attachment structure of the wheel 4 in arbitrary apparatuses other than a caster.
Hereinafter, a second embodiment of the present invention will be described.
The second embodiment relates to 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, a cross-section taken along line CC in FIG. 4b shows that the mounting structure of the wheel 4 in this device includes a device body 6 having a hollow cylindrical bearing portion protruding in the lateral direction, and an elastic member 7. And wheels 8. The shaft portion 81 of the wheel 8 is inserted into the bearing portion 61 of the apparatus body 6, and the hook portion 82 provided at the tip of the shaft portion 81 is locked to the locking portion 62 of the bearing portion. Here, the elastic member 7 has a diameter of one end side 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 having a relatively small diameter so as to be substantially equal to the diameter, and a diameter of the other end portion 712 being 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 surface. However, the covering tube 72 is not necessarily provided.
[0023]
The elastic member 7 has a smaller diameter portion 711 inserted into the bearing portion 61 and the outer peripheral side surface thereof is supported by the inner peripheral side surface of the bearing portion 61. It is not fixed. Further, the portion 712 having the larger diameter of the elastic member 7 that supports the wheel 8 from the inner side 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 portion 61 and does not hinder the rotation of the wheel 8 with respect to the bearing portion 61. In addition, when an impact or pressure is applied to the wheel or the apparatus main body 6, the elastic member 7 is elastically deformed so as to move in a direction in which the force is applied to the larger-diameter portion 712 to buffer the elastic member 7. 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 instrument. For example, the present invention can 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. Moreover, the caster which performs more effective buffering about the arbitrary directions perpendicular | vertical to the rotating shaft of a wheel can be provided.
[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 showing 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: Upper surface, 13: Shaft support 30: Coil spring, 31: Coated tube, 41: Inner ring part, 42: Outer ring part, 43: Bearing, 61: Bearing part, 71: Coil spring, 72: Coated tube, 81: Shaft part.

Claims (4)

A bracket, a shaft installed on the bracket, an elastic member having elasticity around the shaft, and a wheel portion supported by the elastic member having a central hole into which the elastic member is inserted ;
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 is provided on 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 central hole of the wheel portion . The caster according to claim 1 ,
The caster according to claim 1, wherein the elastic member includes a coated tube that covers the coil spring. The caster according to claim 1 or 2 ,
A caster comprising a cover that covers a central hole of the wheel portion in a state where the elastic member is housed in the central hole. A hollow cylindrical bearing portion fixed to a supported body, a wheel portion having an inner peripheral side surface, and an elastic member;
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 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

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