JP3756004B2 - caster - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention, casters, and in particular about the caster over suitable for the front wheels of the wheelchair.
[0002]
[Prior art]
Conventionally, as a wheel shaft support structure of a caster, a structure described in Japanese Patent Laid-Open No. 10-217708 related to the applicant's application is known. As shown in FIG. 9, the caster has a wheel shaft support structure in which a wheel 102 is interposed between a pair of left and right arms 101, 101, a shaft cylinder 103 is provided at the center of the wheel 102, and both ends of the shaft cylinder 103 are provided. Rolling bearings 104 and 104 are fitted, and a supporting shaft 105 supported horizontally between the lower ends of the arms 100 and 100 is inserted into the rolling bearings 104 and 104. The support shaft 105 is fitted with a spacer 106 and a collar collar 107, 107 so as to be interposed between the roller bearings 104, 104 and inside the roller bearings 104, 104, respectively. Each of the collar portions 108 and 108 of the collars 107 and 107 is configured to be interposed between the inner surface of each arm 101 and each rolling bearing 104 facing the arm 101, that is, the side end surface of the shaft tube 103. . Then, both roller bearings 104, 104 are firmly fixed without looseness between the flanges 108, 108 and the spacer 106 via both arms 101, 101 so that the wheel 102 can freely rotate.
[0003]
[Problems to be solved by the invention]
However, in the wheel shaft support structure of the caster, the inner surface of each arm 101 is pushed in such a manner that the respective rolling bearings 104 are pushed inward by the both flange portions 108 and 108 via both arms 101 and 101. A gap G is formed between 101a and each side end surface 103a of the shaft cylinder 103. Therefore, while using a wheelchair, litter such as lint and hair enters the gap G, and the wheel 102 This hinders the smooth rotation of the machine and sometimes makes it impossible to rotate. In addition, accumulation of lint, hair, and other dust in the gap G in this way is not preferable in hospitals where it is required to maintain hygiene and cleanliness. The present invention has been made to solve the above problems, maintain a good rotating state always wheels in the keep out dust into the gap by appropriate concealment means, yet provide preferred caster over even hygiene It is intended to do.
[0004]
[Means for Solving the Problems]
To achieve the above object, casters over according to the present invention, by interposing a wheel between the left and right pair of arms, fitted rolling bearing on the shaft tube side end provided with a shaft tube in the center of the wheel, A support shaft that is horizontally supported between both arms is inserted into both roller bearings, and a wheel is provided so that a gap is provided between the inner side surface of each arm and each side end surface of the shaft cylinder facing this. In the caster that can be freely rotated, the outer periphery of the shaft cylinder is surrounded by an appropriate concealing means so that the outer periphery of the shaft cylinder is not contacted so that dust does not enter the gap.
[0005]
As the concealing means, for example, an annular wall surrounding the outer periphery of the gap is integrally projected on the inner side surface of each arm.
[0006]
Further, as the appropriate concealing means, for example, a dish-shaped member that is mounted on a support shaft is interposed between the gaps, and an annular flange that surrounds the outer periphery of the gap is integrally provided around the outer periphery of the dish-shaped member. To do.
[0007]
Further, as the appropriate concealing means, for example, a flanged collar is interposed between each rolling bearing and the support shaft, and a flange part of the flanged collar is interposed in the gap, and a gap is formed on the outer peripheral edge of the flange part. An annular collar that surrounds the outer periphery is integrally provided.
Note that these concealing means are merely examples, and other means may be used.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
The embodiment of the caster over according to the present invention will be described with reference to the accompanying drawings. FIG. 1 is a perspective view of a wheelchair to which a caster wheel dust-proof structure according to the present invention is applied, FIG. 2 is an exploded perspective view of the main part, and FIG. 3 is a sectional view of the assembled state. A wheelchair 1 shown in FIG. 1 includes a pair of frame-like support members 2, 2 that are arranged on the left and right sides in a foldable manner, and main wheels 3, 3 that are erected at the rear of each support member 2, 2. 4 and operation wheels 5 and 5 are pivotally supported. Further, the support wheels 6, 6, which are suspended from the front portions of the support members 2, 2, are attached to the fixing members 6 a at the lower ends of the support members 6, 6 by inserting and fixing the support wheels 8 of the front wheel casters 7, 7. Both ends of the seat 10 are supported by horizontal rods 9, 9 provided on the support members 2, 2, and both ends of the backrest seat 11 are supported by the upper portions of the main rods 3, 3. Grip portions 12 and 12 for the caregiver to push the wheelchair 1 are provided at the upper ends of the main rods 3 and 3. Footing plates 13 and 13 are provided at the lower front ends of the support members 2 and 2. 14 and 14 are brake levers for stopping the rear wheels 4 and 4.
[0009]
In FIG. 2, reference numeral 15 denotes a fork that rotatably supports the wheel 16 and is integrally formed by plastic injection molding. The fork 15 has a pair of left and right arms 18, 18 projecting from the lower end of the cylindrical body 17, and shaft holes 19, 19 for pivotally supporting the wheels 16 are provided at the distal ends of the arms 18, 18. Then, rolling bearings (not shown) are fitted to the upper and lower ends inside the cylindrical body 17, and the support column 8 is rotatably supported in a horizontal plane via these rolling bearings. .
[0010]
In the wheel 16, a tire portion 20 is integrally formed around the wheel body 16 a by insert injection molding, and a shaft cylinder 22 is provided at the center of a spoke 21 that is radially formed inside, and a shaft formed on the shaft cylinder 22. Bearing holes 25, 25 for fitting the outer rings of the rolling bearings 24, 24 are provided at both left and right ends of the hole 23. Each bearing hole 25, 25 is provided with a larger diameter than the shaft hole 23. Each of the rolling bearings 24, 24 is configured not to protrude outward from each side end face 22 a of the shaft cylinder 22.
[0011]
26 and 26 are collars provided with collars 27 and 27 at one end, and the length of the cylindrical part 28 is set slightly shorter than the width of the rolling bearing 24. Reference numeral 29 denotes a cylindrical spacer interposed in the shaft hole 23 inside the rolling bearings 24, 24. The length of the spacer 29 matches the distance between the rolling bearings 24, 24 fitted in the bearing holes 25, 25. It is set as follows. Then, the outer rings of the rolling bearings 24, 24 are fitted into the bearing holes 25, 25 provided at both ends of the shaft hole 23 with the spacer 29 interposed in the shaft hole 23, respectively. The collars 26 and 26 are fitted and inserted into the shaft insertion holes 30 and 30 so that the collar portions 27 face outward, and communicate with the spacer 29. If the collar 26 and the spacer 29 are made of wear-resistant engineering plastic, dimensional processing is facilitated. Reference numeral 31 denotes a support shaft that is horizontally supported between the arms 18 and 18 and pivotally supports the wheel 16, and a nut 33 is screwed to a screw portion 32 provided at the tip. Reference numerals 34 and 34 are plain washers, and 35 is a spring washer.
[0012]
Next, the assembly of the caster 7 will be described in order. First, a wheel 16 in which the collars 26, 26 and the spacer 29 communicate with each other is interposed between the arms 18, 18 of the fork 15, and a plain washer 34 is supported on the shaft hole 19 on the outside of one arm 18. The shaft 31 is inserted, and the support shaft 31 is inserted in the order of the flanged collar 26 fitted to the rolling bearing 24 of the wheel 16, the spacer 29 and the flanged collar 26, and then inserted into the shaft hole 19 of the other arm 18. Then, after inserting the plain washer 34 and the spring washer 35 into the support shaft 31 protruding to the outside of the arm 18, the nut 33 is screwed into the screw portion 32 at the tip of the support shaft 31 and assembled as shown in FIG. It is done.
[0013]
In the caster 7, the wheel 16 is horizontally supported by the support shaft 31, and both the rolling bearings 24, 24 are received by the spacer 29 on the inner side, and the outer sides are received by the collar portion 27 of the collar 26. In addition, at this time, since the cylindrical portion 28 is slightly shorter than the width of the rolling bearing 24, the inner ends of the cylindrical portions 28, 28 of the flanged collars 26, 26 do not come into contact with both ends of the spacer 29. There are gaps S, S between them, and the roller bearings 24, 24 are firmly supported by the flanges 27, 27 and the spacer 29. As a result, the rolling bearings 24, 24 move along the support shaft and the wheel 16 does not rattle, and the wheel 16 is rotated smoothly and freely. For this reason, since the flange portion 27 is interposed between the inner side surfaces 18a, 18a of the arms 18, 18 and the side end surfaces 22a, 22a of the shaft cylinder 22 opposed thereto, a gap G having a predetermined width is provided. Is formed.
[0014]
As shown in FIG. 4, an annular wall 36 as a concealing means is integrally provided so as to surround the outer periphery of the gap G on the inner side surfaces 18 a, 18 a of both the arms 18, 18. Each of the annular walls 36 is provided so as not to contact the outer peripheral side of both side ends of the shaft cylinder 22 so as not to hinder the rotation operation of the wheel 16. Thus, by concealing each gap G with each annular wall 36, dust such as lint and hair does not enter the gap G, and the wheel 16 can always rotate smoothly.
[0015]
5 and 6 show concealment means according to another embodiment. In this embodiment, as shown in FIG. 5, a plastic dish-like member 37 is used as a concealing means. The dish-shaped member 37 has a shaft support hole 38 through which the support shaft 31 is inserted at the center, and a thick portion 39 having substantially the same thickness as the gap G is provided on the outer periphery thereof. A portion 40 is provided. This is to prevent the rotating outer ring of the rolling bearing 24 from touching. And the annular collar part 41 surrounding the outer periphery of the said clearance gap G is integrally provided in the outer periphery. Further, an annular flange 41a that bends outward is provided around the outer peripheral edge of the annular flange 41. This is because the dish-shaped member 37 is made of plastic, so that the strength is increased and the shape retaining property is improved, and the roundness is easily obtained. In the state of being inserted into the support shaft 31, as shown in FIG. 6, the gap G is concealed so that dust does not enter it. Thus, by forming separately from the arm 18, replacement | exchange at the time of breakage becomes easy. At this time, the collar 26a without wrinkles is used.
[0016]
7 and 8 also show concealment means according to another embodiment. In this embodiment, as shown in FIG. 7, the collar 42 is of the same type as the collar 26, and the collar 43 is greatly enlarged in a circle, and the outer periphery of the collar G surrounds the outer periphery of the gap G. A collar 41 is provided around. Further, an annular flange 41a that bends outward as described above is provided around the outer peripheral edge of the flange 41. Also in this case, a thick part 39 having substantially the same thickness as the gap G on the outer periphery of the cylindrical part 28 and contacting the inner ring of the rolling bearing 24 is provided, and a thin thick part 40 thinner than the gap G is provided on the outer periphery. ing. In this way, it can be used together with the collar 26 according to the present embodiment, and it is easy to replace at the time of breakage, and the cost is low and economical.
[0017]
【The invention's effect】
Casters over according to the present invention, as described above, between the inner surface and this and the side end faces of the opposing barrel of the arms, in casters so as to have a gap, axial by proper concealing means Since the outer periphery of the gap is surrounded so that it does not come into contact with the outer peripheral side of both ends of the cylinder, it is possible to reliably prevent dust such as lint and hair from entering the gap and always The rotation can be performed smoothly. In addition, since dust does not adhere in this way, it has the effect that it is extremely preferable in hospitals and the like that are required to maintain hygiene and cleanliness.
[0018]
As an appropriate concealing means, if an annular wall surrounding the outer periphery of the gap is integrally provided on the inner side surface of each arm, molding can be performed easily.
[0019]
Further, as a concealing means, a dish-like member that is mounted on the support shaft is interposed between the gaps, and an annular flange that surrounds the outer circumference of the gap is integrally provided around the outer peripheral edge of the dish-like member. In this case, replacement at the time of breakage becomes easy.
[0020]
Furthermore, as a concealing means, a flanged collar is interposed between each rolling bearing and the support shaft, and a flange part of the flanged collar is interposed in the gap, and the outer periphery of the flange is surrounded by the outer peripheral edge of the flanged part. If the annular flange portion is integrally provided, not only the replacement at the time of breakage is easy, but also the cost can be reduced and it is extremely economical.
[Brief description of the drawings]
FIG. 1 is a perspective view of a wheelchair to which the present invention is applied.
FIG. 2 is an exploded perspective view of a main part of the present invention.
FIG. 3 is a cross-sectional view showing the assembled state of the main part of the present invention.
4 is an enlarged front view of the main part of FIG. 3;
FIG. 5 is a perspective view of a dish-like member according to another embodiment.
FIG. 6 is a cross-sectional view of a main part using the same dish-shaped member.
FIG. 7 is a perspective view of a collar with a collar according to another embodiment.
FIG. 8 is a cross-sectional view of a main part using the collar with the same collar.
FIG. 9 is a cross-sectional view of a main part showing a conventional example.
[Explanation of symbols]
7 Caster 16 Wheel 18 Arm 18a Inner side 22 Shaft 22a Side end surface 24 Rolling bearing 31 Support shaft 36 Concealing means (annular wall)
37 Concealing means (dish-like member)
41 annular collar 42 	 concealment means (color with collar)
43 Gap G Gap

Claims (1)

A pair of left and right arms, a wheel interposed between the arms and provided with a shaft cylinder at the center, a rolling bearing fitted to both ends of the wheel cylinder of the wheel, and the rolling bearing located inside the rolling bearing A cylindrical spacer having a length that matches the inner space of the arm, and a collar with a collar provided in a gap portion between the inner surface of each arm and each side end surface of the wheel barrel facing the inner surface of the arm, A caster comprising a collar with a collar, a rolling bearing and a support shaft that is inserted through the spacer and rotatably supports the wheel between the arms,
The collar with collar is composed of a cylindrical portion having a length shorter than the width of the shaft insertion hole of the rolling bearing, and a circular collar portion, and further, the portion corresponding to the outer periphery of the cylindrical portion of the collar portion is A thick portion having substantially the same thickness as the gap portion and abutting against the inner ring of the rolling bearing is provided, and an annular flange portion surrounding the outer periphery of the gap portion is provided around the outer peripheral edge of the flange portion. A caster that features.

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