Wheel, caster, and traveling body

Abstract

[Problem] To improve quietness of a wheel having inner and outer wheel separation and an inner-wheel dual wheel structure. [Solution] A wheel according to the present invention is configured such that an inner wheel is disposed inward of an outer wheel in a state of being freely movable within a prescribed range including the radial direction due to a gap being formed in the radial direction between the inner wheel and the outer wheel, the inner wheel is inscribed in an eccentric position of the outer wheel by the outer wheel being grounded, and the inscribed position of the inner wheel can be changed while rolling on the inner surface of the outer wheel. An inner ring is provided integrally with the outer wheel on the inner side of the outer wheel, and a first inner wheel and a second inner wheel are disposed separately from each other as inner wheels at positions sandwiching the inner ring to form a dual wheel structure. A first shaft center of a first shaft member infixed into a shaft hole of the first inner wheel and a second shaft center of a second shaft member infixed into a shaft hole of the second inner wheel are provided at positions eccentric to the axle of the outer wheel.

Description

Wheels, casters and running bodies

[0001] The present invention relates to wheels, casters, and running bodies with separated inner and outer rings that can reduce impact and noise during running, for example, and further to wheels, casters, and running bodies that are designed to improve quietness during running.

[0002] An example of this type of wheel is shown in Patent Document 1. This wheel has an inner ring disposed inside the outer ring with a radial gap formed between it and the outer ring, allowing free movement within a predetermined range including the radial direction, and is configured so that when the outer ring contacts the ground, the inner ring inscribes the outer ring at an eccentric position and can change its inscribed position as it rolls on the inner surface of the outer ring. In this wheel, an inner ring is provided inside the outer ring integrally with the outer ring, and a pair of inner rings are disposed separately from each other at positions sandwiching the inner ring, thereby forming a dual-wheel structure.

[0003] With this configuration, the inner wheel can roll within the outer wheel. Therefore, if the outer wheel collides with an obstacle and locks, or if smooth running is interrupted, and the inertia of an object acting on the inner wheel through the axle, or if an operating force is applied, the inner wheel will first move forward and upward within the outer wheel to a position where it will climb onto the obstacle. Then, biased by the inner wheel, the outer wheel will climb onto the obstacle a little later. This prevents the inertial force of the object from acting directly on the wheel as a collision reaction force, effectively preventing impact and noise. Since the inner wheel can rise to the required height depending on the size of the obstacle, a uniformly effective cushioning effect is achieved, except when the obstacle is extremely large.

[0004] This allows for a simple and inexpensive configuration, reduces the impact and noise when the vehicle collides with an obstacle while traveling, effectively avoids wheel locking, and enables the vehicle to overcome obstacles without requiring excessive operating force, thereby providing a wheel with excellent usability.

[0005] Japanese Patent Application Laid-Open No. 2017-210192

[0006] The wheel of Patent Document 1 can reduce the impact and noise when colliding with an obstacle while traveling, but it is desirable to further reduce the impact and noise and improve noise reduction while traveling.

[0007] The present invention aims to provide wheels, casters, and running bodies with a new support structure based on this perspective.

[0008] In order to achieve the above object, the present invention takes the following measures.

[0009] In other words, the wheel of the present invention is a wheel in which an inner ring is placed inside the outer ring while forming a radial gap between the inner ring and the outer ring, allowing it to move freely within a predetermined range including the radial direction, and when the outer ring comes into contact with the ground, the inner ring inscribes the outer ring at an eccentric position and can change its inscribed position as it rolls on the inner surface of the outer ring, and is characterized in that an inner ring is provided inside the outer ring integrally with the outer ring, and a first inner ring and a second inner ring are arranged separately from each other as the inner rings at positions sandwiching this inner ring, thereby forming a dual-wheel structure, and the first axis of the first shaft member inserted into the shaft hole of the first inner ring and the second axis of the second shaft member inserted into the shaft hole of the second inner ring are located in eccentric positions relative to the axle of the outer ring.

[0010] In this configuration, because the first axis of the first inner ring and the second axis of the second inner ring are misaligned, as the wheel travels, the position where the first inner ring inscribes the outer ring and the position where the second inner ring inscribes the outer ring are different in the direction of travel. Therefore, the location on the outer ring where the downward pressing force from the first inner ring acts and the location on the outer ring where the downward pressing force from the second inner ring acts are different in the direction of travel, causing the outer ring to deform into an elliptical shape. As a result, as the wheel travels, the outer periphery of the outer ring comes into contact with the ground in a flat area, dispersing the downward pressing force from the outer ring to the ground across this area. This further reduces impact and noise when colliding with an obstacle while traveling and improves noise reduction during travel.

[0011] In the wheel of the present invention, it is preferable that an axle portion is arranged inside the inner ring, the first axle member is formed so as to protrude from one end face of the axle portion, and the second axle member is formed so as to protrude from the other end face of the axle portion.

[0012] In this way, it is possible to easily form a configuration in which the first axis of the first inner ring and the second axis of the second inner ring are misaligned.

[0013] In the wheel of the present invention, it is preferable that the direction in which the first axis of the first shaft member is eccentric relative to the axle of the outer wheel is opposite to the direction in which the second axis of the second shaft member is eccentric relative to the axle of the outer wheel.

[0014] This increases the area of ​​the flat region where the outer periphery of the outer ring comes into contact with the ground, and the downward pressure exerted by the outer ring on the ground as the wheel moves is more easily dispersed over this region, making it possible to efficiently mitigate the impact and noise generated when the wheel collides with an obstacle while moving, and further improving noise reduction during movement.

[0015] In the wheel of the present invention, it is preferable that the amount of eccentricity by which the first axis of the first shaft member is eccentric relative to the axle of the outer wheel is the same as the amount of eccentricity by which the second axis of the second shaft member is eccentric relative to the axle of the outer wheel.

[0016] In this way, even if the first axis of the first inner ring and the second axis of the second inner ring are misaligned, the wheel can be rotated smoothly.

[0017] The caster of the present invention is characterized by having any one of the wheels described above assembled thereto.

[0018] In this way, by using a caster equipped with any of the wheels described above, the impact and noise when colliding with an obstacle can be further reduced, and noise reduction can be improved.

[0019] The caster of the present invention preferably includes a stopper portion that presses against the outer peripheral surface of the wheel to prevent the wheel from rotating.

[0020] In this way, when the outer peripheral surface of the wheel is formed of a material with a relatively low hardness, the wheel can be restricted from rotating by pressing the outer peripheral surface of the wheel with a relatively small force.

[0021] The running body of the present invention is characterized in that the above-mentioned casters are attached to it.

[0022] In this way, when moving a running body equipped with casters having any of the above-mentioned wheels attached thereto, the impact and noise when it collides with an obstacle can be further reduced, and noise reduction can be improved.

[0023] In the running body of the present invention, it is preferable that a plurality of casters are attached and that a central locking system is provided which, by pressing the outer surfaces of the wheels included in the plurality of casters, cooperates to restrict the wheels of the plurality of casters from rotating.

[0024] In this way, when the outer surface of the wheel is formed of a material with a relatively low hardness, the wheel can be restricted from rotating by pressing the outer surface of the wheel with a relatively small force, and the wheels of multiple casters can be restricted from rotating in unison.

[0025] According to the present invention as described above, it is possible to further reduce the impact and noise when colliding with an obstacle, and to improve noise reduction.

[0026] 1 is a perspective view of a carry bag 100 having a caster C to which a wheel R according to a first embodiment of the present invention is assembled. FIG. 3(a) is an exploded perspective view of the caster C of FIG. 1. FIG. 3(b) is a side view of the outer ring 1, and FIG. 3(b) is a side view of the inner ring 5. FIG. 4(a) is a side view of the first inner ring 2a and the second inner ring 2b, and FIG. 4(b) is a perspective view of a pair of bosses 3. FIG. 5(a) to FIG. 5(c) are a front view, a right side view, and a left side view of a bushing 6. FIG. 5(a) to FIG. 5(c) are diagrams illustrating the structure of the bushing 6. FIG. 5(c) are diagrams illustrating another structure of the bushing 6. FIG. 5(a) is a cross-sectional view of the wheel R. FIG. 5(b) is a side view of the wheel R. FIG. 5(b) is a diagram illustrating a method for assembling the wheel R. FIG. 12(a) is a diagram illustrating a state in which no downward load is acting on the inner ring 2 of the wheel R according to the first embodiment, and FIG. 12(b) is a diagram illustrating a state in which a downward load is acting on the inner ring 2 of the wheel R according to the first embodiment. FIG. 15( a ) is a diagram showing a state in which a downward load is acting on the inner wheel 102 of the wheel R0 of the comparative example. FIG. 15( b ) is an exploded perspective view of a caster CT1 to which a wheel R according to a second embodiment of the present invention is assembled. FIG. 15( a ) is a perspective view of the stopper portion 130 as seen from above, and FIG. 15( b ) is a perspective view of the stopper portion 130 as seen from below. FIG. 16( a ) is a front view of the caster CT1 in the stopper-off state, and FIG. 16( b ) is a cross-sectional view of the caster CT1 in the stopper-off state. FIG. 17( a ) is a front view of the caster CT1 in the stopper-on state, and FIG. 17( b ) is a cross-sectional view of the caster CT1 in the stopper-on state. FIG. 18( a ) is a perspective view of a carry bag 200 having a caster CT2 to which a wheel R according to a third embodiment of the present invention is assembled, and FIG. 18( b ) is a perspective view showing a central locking system 201 disposed on the carry bag 200. Fig. 19(a) is a perspective view showing an on / off switcher 250 of the central locking system 201, Fig. 19(b) is a perspective view showing a stopper portion 251 of the central locking system 201, and Fig. 19(c) is a perspective view showing a stopper portion 252 of the central locking system 201. Fig. 20(a) is a diagram illustrating the caster CT2 in the stopper-off state, and Fig. 20(b) is a diagram illustrating the caster CT2 in the stopper-on state.

[0027] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0028] (First embodiment) Fig. 1 is a perspective view of a carry bag 100 having a caster C to which a wheel R according to a first embodiment of the present invention is attached. Fig. 2 is an exploded perspective view of the wheel R of the caster C of Fig. 1. Figs. 3(a) and 3(b) are side views of the outer ring 1 and the inner ring 5. Figs. 4(a) and 4(b) are side views of the first inner ring 2a and the second inner ring 2b, and a perspective view of a pair of bosses 3. Figs. 5(a) to 5(c) are a front view, a right side view, and a left side view of a bushing 6.

[0029] As shown in Figures 1 and 2, the carry bag 100 serving as a running body of the present invention has a substantially rectangular parallelepiped shape, and four casters C are attached to its bottom end. Each caster C has a caster body C1 rotatably attached to the bottom surface of the carry bag 100, a pair of left and right brackets C2 attached to the caster body C1, and a wheel R assembled between the pair of left and right brackets C2. The pair of left and right brackets C2 are attached to the caster body C1 so that they can swing. The four casters C have substantially the same structure. Well-known bearings are used to rotatably attach the caster body C1 to the bottom surface of the carry bag 100.

[0030] As shown in FIG. 2, the wheel R has an outer ring 1, a first inner ring 2a and a second inner ring 2b, a pair of bosses 3, a bushing 6, a first mounting member 8a and a second mounting member 8b.

[0031] As shown in FIGS. 3(a) and 8, the outer ring 1 has an annular shape, with rounded corners 12 on both sides of a flat surface 11 on the outer periphery, and is made of a material suitable for rolling on road surfaces, for example, rubber with a relatively low hardness of 50 to 80 degrees hardness.

[0032] 3(b) and 8, the inner ring 5 is made of a material such as PA66 (polyamide 66, commonly known as 6-6 nylon) to provide it with the same mechanical strength as the inner ring 2. The inner ring 5 has an outer circumferential portion 52 with a T-shaped cross section on the outer periphery of a disk portion 51 with eight lightening holes 51a formed at equal angular positions, and is integrally molded (insert molded) with the outer ring 1 in a state where this outer circumferential portion 52 and part of the disk portion 51 are embedded in the outer ring 1.

[0033] As shown in Figures 4(a) and 8, the first inner ring 2a and the second inner ring 2b have bearings 4. As will be described later, the first inner ring 2a is rotatably mounted on a first cylindrical portion 61 (first shaft member), and the second inner ring 2b is rotatably mounted on a second cylindrical portion 62 (second shaft member). The bearing 4 is a well-known rolling bearing having a structure in which balls 41, which serve as rolling elements, are sandwiched and integrated between an inner raceway ring 42 and an outer raceway ring 43, and a mounting hole 42a passes through the inner raceway ring 42.

[0034] The first inner ring 2a and the second inner ring 2b are formed to have approximately the same structure, and are an integrally molded resin body having an outer peripheral portion 22 with a T-shaped cross section outside a disk portion 21 with lightening holes provided at equiangular positions, the outer surface 22a of this outer peripheral portion 22 being the rolling surface, and an inward-facing U-shaped insertion portion 23 on the inner peripheral side. The insertion portion 23 is inserted into the outer raceway 43 of the bearing 4 to a position where it does not interfere with the function of the bearing 4, while embracing both end faces of the outer raceway 43, and is integrated with the outer raceway 43.

[0035] In the first inner ring 2a and the second inner ring 2b, the disk portion 21, outer peripheral portion 22, and insertion portion 23 roll on the inner surface 10 of the outer ring 1 while being supported by the bearing 4, so a material with excellent mechanical strength, such as PA66 (polyamide 66, commonly known as 6-6 nylon), is used for the disk portion 21, outer peripheral portion 22, and insertion portion 23.

[0036] The boss 3 is a metal member, and as shown in Figures 4 and 8, has a first cylindrical portion 31 having an outer diameter that fits into the mounting hole 42a of the bearing 4, a second cylindrical portion 32 having a diameter slightly larger than that of the first cylindrical portion 31, and a flange portion 33 that is expanded at one end of the second cylindrical portion 32, and a step portion 34 is formed at the boundary between the first cylindrical portion 31 and the second cylindrical portion 32.

[0037] The bushing 6 has an axle portion 60 arranged inside the outer ring 1 (inner ring 5), a first cylindrical portion 61 interposed between the inner surfaces of the inner raceways 42 of the bearings 4 of the first inner ring 2a, and a second cylindrical portion 62 interposed between the inner surfaces of the inner raceways 42 of the bearings 4 of the second inner ring 2a. The first cylindrical portion 61 is a first shaft member that is fitted into the shaft hole of the first inner ring 2a, and the second cylindrical portion 62 is a first shaft member that is fitted into the shaft hole of the second inner ring 2a.

[0038] The diameters of the first cylindrical portion 61 and the second cylindrical portion 62 are substantially the same and smaller than the diameter of the axle portion 60. The first cylindrical portion 61 is provided with its axis 61a offset from the axle A of the outer ring 1 (a position offset upward in FIG. 5). The second cylindrical portion 62 is provided with its axis 62a offset from the axle A of the outer ring 1 (a position offset downward in FIG. 5). The direction in which the axis 61a of the first cylindrical portion 61 deviates from the axle A of the outer ring 1 (upward in FIG. 5) and the direction in which the axis 62a of the second cylindrical portion 62 deviates from the axle A of the outer ring 1 (downward in FIG. 5) are opposite each other. The distance by which the axis 61a of the first cylindrical portion 61 deviates from the axle A of the outer ring 1 is the same as the distance by which the axis 62a of the second cylindrical portion 62 deviates from the axle A of the outer ring 1.

[0039] The first inner ring 2a is rotatably provided relative to the first cylindrical portion 61, so that the axis 61a of the first cylindrical portion 61 is also the axis of the first inner ring 2a. The second inner ring 2b is rotatably provided relative to the second cylindrical portion 62, so that the axis 62a of the second cylindrical portion 62 is also the axis of the second inner ring 2b.

[0040] 6 and 7, thread grooves 61t, 62t are formed on the inner peripheral surfaces of the first cylindrical portion 61 and the second cylindrical portion 62. A threaded portion 8t at the tip of the first mounting member 8a is fastened into the thread groove 61t of the first cylindrical portion 61, and a threaded portion 8t at the tip of the second mounting member 8b is fastened into the thread groove 62t of the second cylindrical portion 62.

[0041] 6 , the bushing 6 may be formed by combining the axle portion 60, the first tubular portion 61, and the second tubular portion 62, which are separate members. Specifically, the right end surface of the axle portion 60 may be formed with a hole 60n1 into which a protrusion 61n formed on the first tubular portion 61 is fitted, and the left end surface of the axle portion 60 may be formed with a hole 60n2 into which a protrusion 62n formed on the second tubular portion 62 is fitted. The first tubular portion 61 may be attached to the right end surface of the axle portion 60, and the second tubular portion 62 may be attached to the left end surface of the axle portion 60, to form the bushing 6. The hole portion 60n1 into which the protrusion 61n of the first cylindrical portion 61 is fitted and the hole portion 60n2 into which the protrusion 62n of the second cylindrical portion 62 is fitted are such that, when the bush 6 is configured, the first cylindrical portion 61 is positioned so that its axis 61a is eccentric from the axle A of the outer ring 1, and the second cylindrical portion 62 is positioned so that its axis 62a is eccentric from the axle A of the outer ring 1.

[0042] Furthermore, as shown in Figure 7, the bush 6 may have a first tubular portion 61 formed integrally with the axle portion 60 so as to protrude from the right end face of the axle portion 60, and a second tubular portion 62 formed integrally with the axle portion 60 so as to protrude from the left end face of the axle portion 60.

[0043] As shown in Fig. 8, the inner diameter φ1 of the outer ring 1 is set to be larger than the outer diameter φ2 of the first inner ring 2a and the second inner ring 2b, thereby forming radial gaps between the outer ring 1 and the first inner ring 2a, and between the outer ring 1 and the second inner ring 2b. Therefore, in the state shown in Fig. 9 where the outer ring 1 is eccentric upward relative to the first inner ring 2a, a crescent-shaped gap Δ is formed between the outer ring 1 and the first inner ring 2a. The inner circumference 53 of the inner ring 5 extends further toward the axis 61a of the first inner ring 2a than the crescent-shaped gap Δ, preventing the first inner ring 2a from tipping over.

[0044] The inner diameter φ1 of the outer ring 1 and the outer diameter φ2 of the first inner ring 2a and second inner ring 2b can be set to appropriate dimensions, but if they are too close together the purpose of providing the outer ring 1 and the first inner ring 2a and second inner ring 2b is lost, and conversely if they are too far apart the wheels will kick over bumps on the road surface. As a result of various experiments conducted by the inventors, it was found that for smooth running over bumps, it is effective to keep the ratio φ2:φ1 of φ2 to φ1 within the range of 1:1.2 to 1.4.

[0045] An example of a method for assembling the first inner ring 2a will be described with reference to Figure 10. The insert portion 23 of the first inner ring 2a is inserted into the outer raceway 43 of the bearing 4 so that it is integral with the outer raceway 43. The boss 3 is then inserted into the mounting hole 42a of the inner raceway 42 of the bearing 4 until the stepped portion 34 abuts against the side end face of the inner raceway, thereby assembling the inner ring unit. The inner ring unit is then inserted from the right side into the space on both sides defined by the inner ring 5 inside the outer ring 1. Specifically, the first cylindrical portion 61 formed on the right end face of the axle portion 60 of the bushing 6 located inside the inner ring 5 is inserted into the axial hole of the first inner ring 2a. Finally, the threaded portion 8t at the tip of the first mounting member 8a is tightened into the thread groove 61t of the first cylindrical portion 61. As a result, the bushing 6 is tightened in a state in which the step portion 34 of the boss 3 abuts against the outer surface of the inner raceway 42 of the bearing 4, with the bushing 6 stretched between the inner surfaces of the inner raceways 42 of the bearing 4. The second inner race 2b is also assembled in a similar manner.

[0046] In this state, the outer surface of the inner raceway 42 of the bearing 4 abuts against the stepped portion 34 of the boss 3, restricting the behavior of the gap between the two bearings 4 from widening in the axial direction. As a result, the gap between the first inner ring 2a and the second inner ring 2b fitted to the bearings 4 is also restricted from widening in the axial direction. Furthermore, the inner surface of the inner raceway 42 of the bearing 4 abuts against the bushing 6 interposed between the inner surfaces, restricting the behavior of the gap between the two bearings 4 from narrowing in the axial direction. As a result, the gap between the first inner ring 2a and the second inner ring 2b fitted to the bearings 4 is also restricted from narrowing in the axial direction.

[0047] Furthermore, to ensure that the first inner ring 2a and the second inner ring 2b roll on a stable track on the inner surface 10 of the outer ring 1, rails 22at that are gently convex toward the outer periphery are provided around the axial center of the outer peripheral surfaces 22a of the first inner ring 2a and the second inner ring 2b, and grooves 10t that engage with the rails 22at are provided around the axial center of the inner surface 10 of the outer ring 1. Of course, it is also possible to provide grooves that are gently concave toward the outer periphery in the axial center of the outer peripheral surfaces 22a of the first inner ring 2a and the second inner ring 2b, and to provide rails that engage with the grooves at two corresponding locations on the inner surface 10 of the outer ring 1.

[0048] 2, the wheels R are positioned between the pair of left and right brackets C2 of the caster body C1 and then fastened together with the brackets C2, thereby attaching the wheels R to the caster body C1 and completing the caster C. The brackets C2 maintain a state in which they fasten the flanges 33 of the left and right bosses 3 shown in FIG.

[0049] In this state, the first inner ring 2a and the second inner ring 2b roll stably in the axial direction without any rattle, with the rails 22at guided by the grooves 10t of the outer ring 1, and a predetermined clearance is secured between the outer periphery 22 of the inner ring 2 and the disk portion 51 of the inner ring 5.

[0050] FIG. 11 shows a state in which the axle A of the outer ring 1 of the wheel R of this embodiment, the axle center 61a of the first inner ring 2a, and the axle center 62a of the second inner ring 2b are located at the same height. FIG. 11 illustrates a case in which the axle center 62a of the second inner ring 2b is located downstream of the axle A of the outer ring 1 in the direction of travel, and the axle center 61a of the first inner ring 2a is located upstream of the axle A of the outer ring 1 in the direction of travel. In this state, as shown in FIG. 12( a), when no downward load is applied to the first inner ring 2a and the second inner ring 2b, almost no downward pressing force is applied from the first inner ring 2a and the second inner ring 2b to the inner surface of the outer ring 1, so the outer ring 1 maintains its circular shape. Therefore, the outer periphery of the outer ring 1 comes into contact with the ground in a linear region at position P0 directly below the axle A of the outer ring 1.

[0051] 12(b), when a downward load is acting on the first inner ring 2a and the second inner ring 2b, the first inner ring 2a comes into contact with the outer ring 1 above position P1, which is upstream of the axle A of the outer ring 1 in the direction of travel, and applies a downward pressing force T1 to the inner surface of the outer ring 1 above position P1. The second inner ring 2b comes into contact with the outer ring 1 above position P2, which is downstream of the axle A of the outer ring 1 in the direction of travel, and applies a downward pressing force T2 to the inner surface of the outer ring 1 above position P2. As a result, the outer ring 1 deforms into an elliptical shape, and the outer periphery of the outer ring 1 comes into contact with the ground in a flat area between positions P1 and P2.

[0052] 13 , when a downward load is applied to the two inner rings 102 of the wheel R0 of the comparative example (the wheel described in Patent Document 1), the axis centers 102a of the two inner rings 102 coincide with the axle A of the outer ring 101, and therefore the inner ring 102a is inscribed in the outer ring 101 above position P3 directly below the axle A of the outer ring 101, and applies a downward pressing force T3 to the inner surface of the outer ring 101 above position P3. Therefore, while the outer ring 101 maintains its annular shape, the outer periphery of the outer ring 101 comes into contact with the ground in the linear region at position P3.

[0053] The behavior of the wheel R of this embodiment when traveling on a road surface is basically the same as that of the wheel R0 of Patent Document 1, and since the first inner wheel 2a and the second inner wheel 2b can roll within the outer wheel 1, if the outer wheel 1 collides with an obstacle and locks, or if smooth traveling is interrupted, and the inertia of an object on the wheel acts on the first inner wheel 2a and the second inner wheel 2b through the axle 60a, or if an operating force is applied, the inner wheel of the first inner wheel 2a or the second inner wheel 2b that is downstream in the traveling direction will first move forward and upward within the outer wheel 1 to a position where it will climb up onto the obstacle, and then, biased by this inner wheel, the outer wheel 1 will roll on the inner surface 10 of the outer wheel 1 and climb up onto the obstacle with some delay. Therefore, the inertial force of the object on the wheel R is prevented from acting directly as a collision reaction force, and impact and noise generation can be effectively prevented. In this case, the inner wheel can rise to the required height depending on the size of the obstacle, so that a uniformly effective buffering effect is produced except when the obstacle is extremely large.

[0054] As described above, in the wheel R of this embodiment, the outer ring 1 is deformed into an elliptical shape, so when the outer ring 1 collides with an obstacle and locks, it is easier for the outer ring 1 to climb up onto the obstacle than the wheel R0 of Patent Document 1, and impact and noise generation can be more effectively prevented.

[0055] That is, in the wheel R of this embodiment, as shown in Fig. 12(b), the position P1 where the first inner wheel 2a applies a downward pressing force T1 to the outer wheel 1 and the position P2 where the second inner wheel 2b applies a downward pressing force T2 to the outer wheel 1 are different in the traveling direction, so the outer wheel 1 is deformed into an elliptical shape. As a result, if the wheel R collides with an obstacle and locks while traveling, it is as if the wheel R' (circle shown by the dashed line in Fig. 12(a)) passes through the position P1 where the wheel R contacts the ground and the position P5 where the wheel R contacts the obstacle, and climbs up onto the obstacle. That is, the wheel R', which has a larger radius than the wheel R, climbs up onto the obstacle.

[0056] A case will be described in which a wheel R0 of a comparative example, which has the same radius as the wheel R of the present embodiment, collides with an obstacle and locks. In the wheel R0 of the comparative example, as shown in FIG. 13 , the position P3 at which the first inner wheel 102 applies a downward pressing force T3 to the outer wheel 101 is located directly below the axle A of the outer wheel 101. Therefore, in the wheel R0 of the comparative example, the outer wheel 101 does not deform into an elliptical shape but maintains a circular shape that passes through the position P3 where the wheel R0 contacts the ground and the position P5 where the wheel R0 contacts the obstacle. In contrast, in the wheel R of the present embodiment, the outer wheel 101 deforms into an elliptical shape, creating a state similar to that of a wheel R′ (a circle shown by a dashed line in FIG. 12( b) ) that has a larger radius than the wheel R0 of the comparative example (the same radius when the wheel R of the present embodiment maintains a circular shape) climbing up onto an obstacle. Therefore, the wheel R of the present embodiment is more likely to climb up onto an obstacle than the wheel R0 of the comparative example.

[0057] Furthermore, because the outer periphery of the outer ring 1 comes into contact with the ground in a planar region, the downward pressing force acting from the outer ring 1 on the ground is dispersed in this region. In contrast, in the wheel of the comparative example, the outer periphery of the outer ring 101 comes into contact with the ground in a linear region at position P3, so the downward pressing force acting from the outer ring 101 on the ground is concentrated in the linear region. As a result, the wheel R of this embodiment has improved cushioning properties.

[0058] When descending from an obstacle, the outer ring 1 descends first, and then the inner ring, either the first inner ring 2a or the second inner ring 2b, which is located upstream in the traveling direction, descends from the obstacle slightly later while rolling on the inner surface 10 of the outer ring 1. Therefore, in this case too, impacts and noise can be effectively prevented.

[0059] As described above, the wheel R of this embodiment is a wheel in which an inner ring is arranged inside the outer ring 1 while being able to move freely within a predetermined range including the radial direction by forming a radial gap between the inner ring and the outer ring 1, and when the outer ring 1 comes into contact with the ground, the inner ring is inscribed at an eccentric position on the outer ring 1 and can change its inscribed position as it rolls on the inner surface 10 of the outer ring 1. An inner ring 5 is provided integrally with the outer ring 1 inside the outer ring 1, and the first inner ring 2a and the second inner ring 2b are arranged separately from each other as inner rings at positions sandwiching this inner ring 5, thereby forming a dual-wheel structure, and the first axis 61a of the first tubular portion 61 (first shaft member) inserted into the shaft hole of the first inner ring 2a and the second axis 62a of the second tubular portion 62 (second shaft member) inserted into the shaft hole of the second inner ring 2b are located in eccentric positions relative to the axle A of the outer ring 1.

[0060] In this configuration, the first axis 61a of the first inner ring 2a and the second axis 62a of the second inner ring 2b are misaligned, so that as the wheel R travels, the position where the first inner ring 2a inscribes the outer ring 1 and the position where the second inner ring 2b inscribes the outer ring 1 are different in the direction of travel. Therefore, the location on the outer ring 1 where the downward pressing force from the first inner ring 2a acts and the location on the outer ring 1 where the downward pressing force from the second inner ring 2b acts are different in the direction of travel, causing the outer ring 1 to deform into an elliptical shape. As a result, as the wheel R travels, the outer periphery of the outer ring 1 comes into contact with the ground in a flat region, so the downward pressing force acting from the outer ring 1 on the ground is dispersed over this region. This further reduces impact and noise when the wheel collides with an obstacle while traveling and improves noise reduction during travel.

[0061] In the wheel R of this embodiment, the axle portion 60 is arranged inside the inner ring 5, and the first tubular portion 61 (first axle member) is formed to protrude from one end face of the axle portion 60, and the second tubular portion 62 (second axle member) is formed to protrude from the other end face of the axle portion 60.

[0062] In this way, it is possible to easily form a configuration in which the first axis 61a of the first inner ring 2a and the second axis 62a of the second inner ring 2b are misaligned.

[0063] In the wheel R of this embodiment, the direction in which the first axis 61a of the first tubular portion 61 is eccentric relative to the axle A of the outer ring 1 is opposite to the direction in which the second axis 62a of the second tubular portion 62 is eccentric relative to the axle A of the outer ring 1.

[0064] This increases the area of ​​the flat region where the outer periphery of the outer ring 1 comes into contact with the ground, and therefore the downward pressing force acting from the outer ring 1 on the ground when the wheel R is running is more easily dispersed in this region. This makes it possible to efficiently mitigate the impact and noise when hitting an obstacle while running, and further improves noise reduction during running.

[0065] In the wheel R of this embodiment, it is preferable that the amount of eccentricity by which the first axis 61a of the first tubular portion 61 is eccentric relative to the axle A of the outer wheel 1 is the same as the amount of eccentricity by which the second axis 62a of the second tubular portion 62 is eccentric relative to the axle A of the outer wheel 1.

[0066] In this way, even if the first axis 61a of the first cylindrical portion 61 and the second axis 62a of the second cylindrical portion 62 are misaligned, the wheel R can be rotated smoothly.

[0067] The caster C of this embodiment has a wheel R attached thereto.

[0068] In this way, by using a caster C with a wheel R attached thereto, the impact and noise when colliding with an obstacle can be further reduced, and noise reduction can be improved.

[0069] The carry bag 100 of this embodiment has casters C attached thereto.

[0070] In this way, when moving a carry bag 100 equipped with casters C to which wheels R are attached, the impact and noise when it collides with an obstacle can be further reduced, and noise reduction can be improved.

[0071] (Second embodiment) The caster CT1 of this embodiment differs from the caster C of the first embodiment in that the caster CT1 of this embodiment can restrict the rotation of the wheel R by a stopper portion 130. Other configurations of the caster CT1 of this embodiment are the same as those of the caster C of the first embodiment, and therefore detailed description thereof will be omitted.

[0072] As shown in Figure 14, the caster CT1 has a caster body C1 rotatably attached to the bottom surface of the carry bag 100, a pair of left and right brackets C2 attached to the caster body C1, and a wheel R assembled between the pair of left and right brackets C2.

[0073] Two mounting holes 131 (see FIGS. 16(b) and 17(b)) for attaching the stopper portions 130 are formed in the caster body C1. The two mounting holes 131 are arranged parallel to each other and penetrate the caster body C1. The caster CT1 can be used without the stopper portions 130 attached, or with the stopper portions 130 attached. Therefore, when the caster CT1 is used without the stopper portions 130 attached, both ends of the two mounting holes 131 are covered with cover members 131a.

[0074] As shown in Figure 15, the stopper portion 130 has a stopper body 132 formed by bending a metal plate-like member. The stopper body 132 has two support portions 132a arranged in parallel and a connecting portion 132b connecting the two support portions 132a. The two support portions 132a are bent vertically downward at both ends of the connecting portion 132b. Therefore, the two support portions 132a and the connecting portion 132b form an accommodation space 133 that opens downward.

[0075] The two support portions 132a each have an attachment portion 150 that is used when attaching the stopper portion 130 to the caster CT1. The two attachment portions 150 are arranged parallel to each other along the two support portions 132a, and two attachment shafts 151 are detachably formed between them.

[0076] An operating portion 134 and a rotation restricting portion 136 are disposed in the accommodation space 133 .

[0077] The operating unit 134 is swingably connected to the two support units 132a by a shaft member 152 within the accommodation space 133. The operating unit 134 has a crank 135 disposed adjacent to the shaft member 152. When the operating unit 134 swings around the shaft member 152 as a fulcrum, the crank 135 also swings around the shaft member 152 as a fulcrum.

[0078] The rotation restricting portion 136 is formed of a metal leaf spring and is attached to the underside of the connecting portion 132b by two mounting members 153. The rotation restricting portion 136 has a fixed portion 136a attached to the underside of the connecting portion 132b and a movable portion 136b extending from the end of the fixed portion 136a. The movable portion 136b is bent at the end of the fixed portion 136a (the end farther from the operating portion 134) and is positioned so as to face the fixed portion 136a. The fixed portion 136a and the movable portion 136b are connected at a predetermined angle, and the distance between the fixed portion 136a and the movable portion 136b increases with increasing distance from the connection portion.

[0079] When no external force is acting on the movable part 136b, the angle between the fixed part 136a and the movable part 136b is maintained at a predetermined angle. When an external force acts on the movable part 136b in a direction away from the fixed part 136a, the movable part 136b elastically deforms in a direction away from the fixed part 136a, with the connection part with the fixed part 136a as a fulcrum. Thereafter, when the external force ceases to act, the movable part 136b moves by elastic force in a direction toward the fixed part 136a, with the connection part with the fixed part 136a as a fulcrum, and the angle between the movable part 136b and the fixed part 136a returns to a state where the angle is the predetermined angle.

[0080] The crank 135 of the operating unit 134 is disposed between the fixed portion 136a and the movable portion 136b of the rotation restricting unit 136. As shown in FIG. 15B , a first flat portion 135a and a second flat portion 135b are formed at the lower end of the crank 135. The first flat portion 135a is a portion that comes into contact with the upper surface of the movable portion 136b of the rotation restricting unit 136 when no external force is acting on the operating unit 134. In contrast, the second flat portion 135b is a portion that comes into contact with the upper surface of the movable portion 136b of the rotation restricting unit 136 when an external force is acting on the operating unit 135 in a downward direction.

[0081] 16(a) and 16(b), when no external force is acting on the operating unit 134, the first flat portion 135a of the crank 135 does not press the movable portion 136b of the rotation restricting unit 136 toward the outer wheel 1 of the caster CT1. At that time, the movable portion 136b of the rotation restricting unit 136 is separated from the outer peripheral surface of the wheel R of the caster CT1, so the rotation of the wheel R is not restricted. Note that in the stopper-off state, the position of the operating unit 134 is maintained with the first flat portion 135a of the crank 135 in contact with the upper surface of the movable portion 136b of the rotation restricting unit 136.

[0082] In the stopper portion 130, the distance between the second flat portion 135b of the crank 135 and the shaft member 152 is greater than the distance between the first flat portion 135a of the crank 135 and the shaft member 152. Therefore, when the crank 135 is pushed down to switch to the stopper-on state and an external force acts on the operating portion 134 in a downward direction, as shown in FIGS. 17( a) and 17(b), the operating portion 134 swings around the shaft member 152 as a fulcrum, and the second flat portion 135b presses the movable portion 136b of the rotation restricting portion 136 toward the wheel R of the caster CT1 against the biasing force of the leaf spring of the rotation restricting portion 136. At that time, as shown in FIG. 17(b), the movable portion 136b of the rotation restricting portion 136 comes into contact with the outer peripheral surface of the wheel R of the caster CT1, restricting the rotation of the wheel R so that the wheel R does not rotate. In the stopper-off state, the position of the operating part 134 is maintained with the second flat part 135b of the crank 135 in contact with the upper surface of the movable part 136b of the rotation restricting part 136.

[0083] When switching from the stopper-on state to the stopper-off state, the operating member 134 swings upward with the shaft member 152 as a fulcrum, switching to the stopper-off state and the first flat portion 135a of the crank 135 comes into contact with the upper surface of the movable portion 136b of the rotation restricting portion 136. Therefore, the movable portion 136b of the rotation restricting portion 136 moves to a position away from the outer peripheral surface of the wheel R of the caster CT1, and the state in which the rotation of the wheel R is restricted is released.

[0084] In the caster CT1 of this embodiment, when attaching the stopper portion 130 to the caster CT, first, the cover member 131a covering the two mounting holes 131 is removed. Then, the two mounting shafts 151 of the stopper portion 130 are removed from between the two mounting portions 150, and the caster body C1 is placed between the two mounting portions 150. In this state, the two mounting shafts 151 are passed through the two mounting holes 131 formed in the caster body C1 and attached to the two mounting portions 150. This completes the attachment of the stopper portion 130 to the caster CT.

[0085] As described above, the wheel R and caster CT1 of this embodiment can achieve the same effects as the wheel R and caster C of the first embodiment.

[0086] The caster CT1 of this embodiment is provided with a stopper portion 130 that presses the outer peripheral surface of the wheel R to prevent the wheel R from rotating.

[0087] In this way, when the outer peripheral surface of the wheel R is formed of a material with a relatively low hardness, the wheel R can be restricted from rotating by pressing the outer peripheral surface of the wheel R with a relatively small force.

[0088] (Third embodiment) The caster CT2 of this embodiment differs from the caster C of the first embodiment in that the caster CT2 of this embodiment can restrict the rotation of the wheel R by a central locking system 201. Other configurations of the caster CT2 of this embodiment are the same as those of the caster C of the first embodiment, and therefore detailed description thereof will be omitted.

[0089] As shown in Figures 18(a) and 18(b), the casters CT2 are attached to the bottom surface of the carry bag 200. The carry bag 200 has a central locking system 201 for restricting the rotation of the wheels R of the casters CT2. The central locking system 201 can restrict the rotation of the wheels R so that the wheels R of the two casters CT2 attached to the bottom surface of the carry bag 200 do not rotate. The two casters C other than the two casters CT2 attached to the bottom surface of the carry bag 200 are the same as the casters C in the first embodiment.

[0090] As shown in Figure 18 (b), the central locking system 201 has an on / off switch 250 arranged on the side of the carry bag 200 and two stopper parts 251, 252 arranged on the bottom surface of the carry bag 200.

[0091] 19(a), the on / off switcher 250 has a frame member 253 attached to the outer peripheral surface of the side of the carry bag 200, and an operating unit 254 arranged so as to be movable up and down relative to the frame member 253. The operating unit 254 is movable between an unlocked position located at the upper inside of the frame member 253 and a locked position located at the lower inside of the frame member 253. A holding unit 255 is integrally formed on the back surface of the operating unit 254. The upper end of a lever 257 is connected to the holding unit 255 by a shaft member 256.

[0092] 19(b), the stopper portion 251 has two support members 258 fixed to the bottom surface of the carry bag 200, a shaft member 259 supported by the two support members 258, a cam 260 and a crank 261 that are rotatable around the shaft member 259 as a fulcrum, and a stopper shaft 262 disposed below the crank 261. The lower end of the lever 257 is connected to one end of the cam 260, and the upper end of the crank 261 is connected to the other end of the cam 260 so as to be rotatable around the shaft member 263 as a fulcrum. A lever 264 is connected to the upper end of the crank 261 so as to be rotatable around the shaft member 263 as a fulcrum.

[0093] 19(c), the stopper portion 252 has two support members 265 fixed to the bottom surface of the carry bag 200, a shaft member 266 supported by the two support members 265, a crank 267 that can rotate around the shaft member 266 as a fulcrum, and a stopper shaft 280 that is disposed below the crank 267. A lever 264 is connected to the upper end of the crank 267 so as to be rotatable around a shaft member 268 as a fulcrum.

[0094] In the stopper portion 251, the stopper shaft 262 is a metal member that, as shown in Figures 20(a) and 20(b), penetrates the bottom surface of the carry bag 200 and the caster body C1 and is arranged to be able to move up and down. The stopper shaft 262 has an acting portion 262a that contacts the lower end of the crank 261, a rotation restricting portion 262b that faces the outer peripheral surface of the wheel R of the caster CT2, and a connecting portion 262c that connects the acting portion 262a and the rotation restricting portion 262b. The connecting portion 262c is arranged inside the spring 262T. The upper end of the spring 262T contacts the lower surface of the acting portion 262a, and the lower end of the spring 262T is supported by a support surface 262N within the bottom surface of the carry bag 200.

[0095] The crank 261 is arranged to come into contact with the upper surface of the acting portion 262a of the stopper shaft 262. As shown in Figures 20(a) and 20(b), the crank 261 is formed with a first flat portion 261a and a second flat portion 261b. The first flat portion 261a is a portion that comes into contact with the upper surface of the acting portion 262a of the stopper shaft 262 when no force is acting to press down on the acting portion 262a. In contrast, the second flat portion 261b is a portion that comes into contact with the upper surface of the acting portion 262a of the stopper shaft 262 when a force is acting to press down on the acting portion 262a.

[0096] 20(a), when no downward force is applied to the acting portion 262a, the first flat portion 261a of the crank 261 does not press downward on the acting portion 262a of the stopper shaft 262. At that time, the rotation restricting portion 262b of the stopper shaft 262 is separated from the outer peripheral surface of the wheel R of the caster CT2, so the rotation of the wheel R is not restricted. Note that in the stopper off state, the position of the crank 261 is maintained with the first flat portion 261a of the crank 261 in contact with the upper surface of the acting portion 262a of the stopper shaft 262.

[0097] In the stopper portion 251, the distance between the second flat portion 261b of the crank 261 and the shaft member 259 is greater than the distance between the first flat portion 261a of the crank 261 and the shaft member 259. Therefore, when the crank 261 rotates clockwise to switch to the stopper-on state and a downward force acts on the acting portion 262a, as shown in FIG. 20(b), the second flat portion 261b presses downward on the acting portion 262a of the stopper shaft 262. At that time, the stopper shaft 262 descends against the biasing force of the spring 262T, and the rotation restricting portion 262b of the stopper shaft 262 comes into contact with the outer peripheral surface of the wheel R of the caster CT, restricting the rotation of the wheel R so that the wheel R does not rotate. In the stopper-on state, the position of the crank 261 is maintained with the second flat portion 261 b of the crank 261 in contact with the upper surface of the acting portion 262 a of the stopper shaft 262 .

[0098] When switching from the stopper-on state to the stopper-off state, the crank 261 rotates left to switch to the stopper-off state, and the stopper shaft 262 rises due to the biasing force of the spring 262T, raising the stopper shaft 262. Therefore, the rotation restricting portion 262b of the stopper shaft 262 moves to a position away from the outer circumferential surface of the wheel R of the caster CT2, and the state in which the rotation of the wheel R is restricted is released.

[0099] In the carry bag 200, the central locking system 201 will be described below for switching from a stopper-off state, in which the rotation of the wheels R of the two casters CT2 is not restricted, to a stopper-on state, in which the wheels R of the two casters CT2 are restricted from rotating.

[0100] In the on / off switcher 250, the operating unit 254 is moved from the unlocked position to the locked position. Then, in the stopper 251, the lower end of the lever 257 moves downward, as shown in Figure 19(b), and the cam 260 rotates clockwise around the shaft member 259. At the same time, the other end of the cam 260 moves clockwise around the shaft member 259, and the upper end of the crank 261 connected to the other end of the cam 260 rotates clockwise around the shaft member 259.

[0101] As a result, the second flat surface 261b formed on the lower end of the crank 261 comes into contact with the upper surface of the stopper shaft 262, and the stopper shaft 262 descends against the biasing force of the spring 262T. At this time, the lower surface of the stopper shaft 262 presses against the outer peripheral surface of the wheel R of the caster CT2, as shown in Figure 20(b), restricting the rotation of the wheel R so that the wheel R of the caster CT2 does not rotate. At this time, the lever 264 connected to the upper end of the crank 261 moves to the right.

[0102] At this time, in the stopper portion 252, the left end of the lever 264 moves to the right, causing the crank 267 to rotate clockwise around the shaft member 266 as a fulcrum. This causes a transition from a state in which the first flat portion 267a formed at the lower end of the crank 267 contacts the upper surface of the stopper shaft 280 to a state in which the second flat portion 261b formed at the lower end of the crank 267 contacts the upper surface of the stopper shaft 280. As with the stopper portion 251, the distance between the second flat portion 267b and the shaft member 266 is greater than the distance between the first flat portion 267a and the shaft member 266, causing the stopper shaft 280 to descend. At this time, the lower surface of the stopper shaft 280 presses against the outer peripheral surface of the wheel R of the caster CT2, restricting the rotation of the wheel R so that the wheel R of the caster CT2 does not rotate. In the stopper-on state, the position of the crank 267 is maintained with the second flat portion 267b of the crank 267 in contact with the upper surface of the stopper shaft 280.

[0103] In the carry bag 200, the central locking system 201 switches from a stopper-on state, which restricts the rotation of the wheels R of the two casters CT2, to a stopper-off state, which does not restrict the rotation of the wheels R of the two casters CT2. A detailed explanation will be omitted, but when the operating unit 254 in the on / off switching unit 250 is moved from the locked position to the unlocked position, the lever 257 moves upward and the lever 264 moves to the left, and the stopper units 251 and 252 return to the state shown in Figure 19, thereby releasing the state restricting the rotation of the wheels R of the two casters CT2.

[0104] As described above, the wheel R and caster CT2 of this embodiment can achieve the same effects as the wheel R and caster C of the first embodiment.

[0105] The carry bag 200 of this embodiment is equipped with two casters CT2 and a central locking system 201 that works in conjunction with the casters CT2 to prevent the wheels R of the two casters CT2 from rotating by pressing against the outer surfaces of the wheels R included in the two casters CT2.

[0106] In this way, when the outer peripheral surface of the wheel R is formed of a material with a relatively low hardness, the wheel R can be restricted from rotating by pressing the outer peripheral surface of the wheel R with a relatively small force, and the wheels R of the two casters CT2 can be restricted in conjunction with each other so as not to rotate.

[0107] The above describes an embodiment of the present invention, but the specific configurations and materials of each part are not limited to the above-described embodiment, and various modifications are possible within the scope of the spirit of the present invention.

[0108] For example, in the first embodiment described above, the direction in which the axis center 61 a of the first tubular portion 61 deviates from the axle A of the outer ring 1 and the direction in which the axis center 62 a of the second tubular portion 62 deviates from the axle A of the outer ring 1 are opposite each other, and the distance by which the axis center 61 a of the first tubular portion 61 deviates from the axle A of the outer ring 1 and the distance by which the axis center 62 a of the second tubular portion 62 deviates from the axle A of the outer ring 1 are the same, but this is not limited to this. The wheel R of the present invention can achieve the effects of the present invention when the first axis center 61 a of the first shaft member 61 inserted into the shaft hole of the first inner ring 2 a and the second axis center 62 a of the second shaft member 62 inserted into the shaft hole of the second inner ring 2 b are positioned eccentrically with respect to the axle A of the outer ring 1. The same applies to the second and third embodiments described above.

[0109] In the first embodiment, the running body of the present invention is described as a carry bag 100 equipped with a caster C having a wheel R attached thereto, but the present invention is not limited thereto. The running body of the present invention may be any running body equipped with a wheel R of the present invention or a caster C having a wheel R attached thereto. In other words, the wheel R of the present invention or a caster C having a wheel R attached thereto can be applied to running bodies other than the carry bag 100. In addition to carry bags, running bodies of the present invention include dollies, carts, pushcarts, vehicles, and, for example, running bodies that move on the ground and running bodies that are required to move over bumps or obstacles in the road surface (various consumer products, industrial machinery, etc.). The same applies to the second and third embodiments.

[0110] In the first embodiment, the inner ring 5 and the outer ring 1 do not necessarily have to be integrally molded, but may be molded separately and then integrated or connected together. The same applies to the second and third embodiments.

[0111] In the first embodiment, a first restricting portion is provided that presses the boss against the inner raceway of the bearing to restrict the behavior of the inner raceway spacing from widening, but if a boss is not used, the same effect can be achieved by making the inner raceway of the bearing wider than the outer raceway so that a restricting force acts directly on this inner raceway. The same applies to the second and third embodiments.

[0112] In the first embodiment, a structure in which the outer ring is single and the inner ring is double was described. However, wheels and casters similar to the above embodiment can also be constructed by placing the inner ring inside each outer ring and positioning inner rings integrated with each outer ring between the inner rings. In this case, a retaining plate with a diameter larger than the inner diameter of the inner ring is placed between the inner rings and passed through the axle, preventing both ends of the axle from slipping out. The axle can be supported by the caster body between the retaining plates to properly hold the outer ring. The same applies to the second and third embodiments.

[0113] In the third embodiment, the levers 257 and 264 are used in the central locking system 201 to interlock and restrict the wheels R of the two casters CT2 from rotating, but this is not limiting. For example, instead of the levers 257 and 264, a wire may be used to interlock and restrict the wheels R of the two casters CT2 from rotating.

[0114] The wheel of the present invention can be used for various consumer products and industrial machines that are required to travel over bumps and obstacles in the road surface, including dollies, carry bags, carts, pushcarts, and vehicles.

[0115] DESCRIPTION OF SYMBOLS 1 Outer ring 2a First inner ring 2b Second inner ring 3 Boss 4 Bearing 5 Inner ring 6 Bush 60 Axle portion 61 First cylindrical portion (first shaft member) 62 Second cylindrical portion (second shaft member) 61a First shaft center 62a Second shaft center 100 Carry bag (traveling body) A Axle C Caster R Wheel 130 Stopper portion CT1 Caster 200 Carry bag (traveling body) 201 Central locking system 250 Stopper portion 251 Stopper portion CT2 Caster

Claims

1. A wheel in which an inner ring is placed inside an outer ring while being free to move within a prescribed range including the radial direction by forming a gap between the inner ring and the outer ring in the radial direction, and the inner ring is inscribed in an eccentric position of the outer ring when the outer ring touches the ground, and the inscribed position can be changed as it rolls on the inner surface of the outer ring, wherein an inner ring is provided inside the outer ring integrally with the outer ring, and a first inner ring and a second inner ring are provided separately from each other at positions sandwiching the inner ring, thereby forming a twin wheel structure, and a first axis of a first shaft member inserted into the shaft hole of the first inner ring and a second axis of a second shaft member inserted into the shaft hole of the second inner ring are provided in eccentric positions with respect to the axle of the outer ring.

2. The wheel according to claim 1, characterized in that an axle portion is disposed inside the inner ring, the first axle member is formed so as to protrude from one end face of the axle portion, and the second axle member is formed so as to protrude from the other end face of the axle portion.

3. A wheel as described in claim 1 or 2, characterized in that the direction in which the first axis of the first shaft member is eccentric relative to the axle of the outer wheel is opposite to the direction in which the second axis of the second shaft member is eccentric relative to the axle of the outer wheel.

4. A wheel as described in claim 1 or 2, characterized in that the amount of eccentricity of the first axis of the first shaft member relative to the axle of the outer wheel is the same as the amount of eccentricity of the second axis of the second shaft member relative to the axle of the outer wheel.

5. A caster having the wheel according to claim 1 or 2 mounted thereon.

6. A caster as described in claim 5, further comprising a stopper portion that presses against the outer circumferential surface of the wheel to restrict the wheel from rotating.

7. A running body having the caster according to claim 5 or 6 attached thereto.

8. A running vehicle as described in claim 7, characterized in that it is equipped with a plurality of casters and is provided with a central locking system that presses against the outer circumferential surfaces of the wheels included in the plurality of casters, thereby interlocking and restricting the wheels of the plurality of casters from rotating.

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