caster

Abstract

To provide a caster capable of stopping rotation of a wheel and turning of a fork by one operation.SOLUTION: A caster 1 comprises: a wheel 2; a fork 3; an attaching seat unit 4; and a stopper unit 5 that is attached to the fork 3 and that stops rotation of the wheel 2 and turning of the fork 3. The fork 3 can be turned with respect to the attaching seat unit 4. The stopper unit 5 includes a wheel pressing tool 51 that presses the wheel 2 to stop the rotation of the wheel 2, a turning stop tool 52 that is locked to the attaching seat unit 4 to stop the turning of the fork 3, a pedal 54 that operates the stopper unit 5, and pedal arms 53A, 53B that transmit power of the operated pedal 54 to the wheel pressing tool 51 and the turning stop tool 52. When the pedal 54 is pushed in, the wheel pressing tool 51 presses the wheel 2, and the turning stop tool 52 is locked to the attaching seat unit 4.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a caster attached to a transport carriage or the like. [Background Art]

[0002] As a caster used by being attached to a carriage, for example, the caster (3) described in Patent Document 1 is known. This caster (3) includes a wheel (4), a base member (5), a brake operation pedal (6), and a fixing member (7).

[0003] The wheel (4) is rotatably attached to the base member (5) about a horizontal axis, and the brake operation pedal (6) is attached to the base member (5) via the fixing member (7). Further, the wheel (4) is turnably attached to the base member (5) about a vertical axis.

[0004] The brake operation pedal (6) is swingably supported with respect to the fixing member (7) via a swing shaft (72). By pressing down the brake operation pedal (6), the rotation of the wheel (4) about the horizontal axis can be stopped (a brake can be applied). Further, when the brake operation pedal (6) is lifted up, the wheel (4) becomes rotatable about the horizontal axis (the brake is released). [Prior Art Documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Unexamined Patent Publication No. 2023-158845 [Brief Summary of the Invention] [Problem to be Solved by the Invention]

[0006] The caster (3) described in Patent Document 1 has a mechanism for stopping the rotation of the wheel (4) about the horizontal axis, but does not have a mechanism for stopping the rotation of the wheel (4) about the vertical axis.

[0007] Therefore, the present invention aims to solve the above problems and provide a caster that can stop the rotation of the wheels and the swivel of the forks with a single operation. [Means for solving the problem]

[0008] The caster according to the present invention comprises a wheel, a fork that rotatably holds the wheel, a mounting seat unit attached to the upper part of the fork, and a stopper unit attached to the fork that stops the rotation of the wheel and the swivel of the fork, wherein the fork is swivelable relative to the mounting seat unit, and the stopper unit comprises a wheel retainer that presses against the wheel to stop its rotation, a swivel stopper that engages with the mounting seat unit to stop the swivel of the fork, a pedal for operating the stopper unit, and a pedal arm that transmits the power of the operated pedal to the wheel retainer and the swivel stopper. The pedal has a pair of left and right fixing parts fixed to the pedal arm, and a display holding part connecting the left and right fixing parts, and when viewed from above, the wheel is visible between the left and right fixing parts, and the display holding part is located behind the wheel. When the pedal is pressed, the wheel retainer presses against the wheel, and the swivel stopper engages with the mounting seat unit. [Effects of the Invention]

[0009] According to the caster of the present invention, the rotation of the wheels and the rotation of the forks can be stopped with a single operation. [Brief explanation of the drawing]

[0010] [Figure 1] This is a right side view of an unlocked caster according to one embodiment of the present invention. [Figure 2] This is a right side view showing a cross-sectional view of a portion of the caster in the unlocked state of the same embodiment. [Figure 3] This is a right side view showing a cross-sectional view of a portion of the caster in the locked state of the same embodiment. [Figure 4] This is a plan view of the caster in the unlocked state according to the same embodiment. [Figure 5]FIG. 1 is a front view, partially in cross-section, of a caster in an unlocked state according to the same embodiment. [Figure 6] FIG. 2 is a plan view of a fork according to the same embodiment. [Figure 7] FIG. 6 is a cross-sectional view taken along line A-A of FIG. 6. [Figure 8] FIG. 9 is a cross-sectional view taken along line B-B of FIG. 9. [Figure 9] FIG. 1 is a front view of a fork according to an embodiment of the present invention. [Figure 10] FIG. 1 is a right side view of a wheel retainer according to the same embodiment. [Figure 11] FIG. 1 is a plan view of the wheel retainer according to the same embodiment. [Figure 12] FIG. 1 is a rear view of the wheel retainer according to the same embodiment. [Figure 13] FIG. 1 is a right side view of a rotation stopper according to the same embodiment. [Figure 14] FIG. 1 is a plan view of the rotation stopper according to the same embodiment. [Figure 15] FIG. 1 is a rear view of the rotation stopper according to the same embodiment. [Figure 16] FIG. 1 is a right side view of a pedal arm according to the same embodiment. [Figure 17] FIG. 1 is a plan view of the pedal arm according to the same embodiment. [Figure 18] FIG. 1 is a rear view of the pedal arm according to the same embodiment. [Figure 19] FIG. 1 is a right side view of a pedal according to the same embodiment. [Figure 20] FIG. 1 is a plan view of the pedal according to the same embodiment. [Figure 21] FIG. 1 is a rear view of the pedal according to the same embodiment. [Figure 22] FIG. 1 is a right side view of an identification indicator according to the same embodiment. [Figure 23] FIG. 1 is a plan view of the identification indicator according to the same embodiment. [Figure 24] FIG. 1 is a front view of the identification indicator according to the same embodiment. MODE FOR CARRYING OUT THE INVENTION

[0011] Preferred embodiments of the present invention will be described with reference to the accompanying drawings. Note that not all of the configurations described below are essential requirements of the present invention.

[0012] Figures 1 to 5 show a caster 1 according to one embodiment of the present invention. The caster 1 is a swivel caster that can be attached, for example, to the lower corners of a transport cart (not shown), and has a wheel 2, a fork 3, a mounting seat unit 4, and a stopper unit 5. When the caster 1 is attached to a transport cart, the right side of Figure 1 is the direction of travel. In the following description, the direction of travel will be referred to as the front side of the caster 1, the left side of Figure 1 as the rear side of the caster 1, the left side of the direction of travel as the left side of the caster 1, and the right side of the direction of travel as the right side of the caster 1.

[0013] As shown in Figures 1 to 5, the wheel 2 has a urethane resin tire 12 attached to the outer circumference of a metal wheel 11. An axle hole 14 is formed in the center of the wheel 11 through which a shaft 13, which serves as the axle, is inserted. A ball bearing 15 is arranged inside the wheel 11, allowing the wheel 2 to rotate around the shaft 13 as its axis. In other words, the wheel 2 is rotatable around a horizontal axis. The shaft 13 is inserted through the axle hole 14 of the wheel 11 and the axle holes 24A and 24B of the fork 3, which will be described later, and is fixed to the fork 3 by an axle nut 16.

[0014] As shown in Figures 6 to 9, the fork 3 integrally comprises plate-shaped side plates 21A and 21B arranged on the left and right sides of the wheel 2, an annular base 22 formed on the upper part of the side plates 21A and 21B, and an upper plate 23 formed on the rear side of the base 22 and connecting the side plates 21A and 21B. The lower part of the side plate 21A has a circular through-hole, the axle hole 24A, through which the shaft 13 is inserted, and the lower part of the side plate 21B has a square through-hole, the axle hole 24B, through which the shaft 13 is inserted. Furthermore, the upper part of the side plate 21A has an oval through-hole, the outer axle movement hole 25A, and the upper part of the side plate 21B has an oval through-hole, the outer axle movement hole 25B, and the upper part of the side plate 21B has an oval through-hole, the outer axle movement hole 25B, and the upper part of the side plate 21B has a circular through-hole, the outer axle movement hole 26B.

[0015] A circular through-hole, the upper hole 27, is formed in the approximate center of the base portion 22. An upper ball groove 30, through which the bearing balls 29 roll, is formed in the upper surface portion 28 of the base portion 22, and a lower ball groove 33, through which the bearing balls 32 roll, is formed in the lower surface portion 31 of the base portion 22. The front portion of the base portion 22 extends downwards in a bent shape. The rear portion of the base portion 22 also extends downwards in a bent shape and connects to the upper plate portion 23.

[0016] As shown in Figures 1 to 5, the mounting base unit 4 has a top plate 41 and a hollow shaft portion 42. The top plate 41 is the part that attaches the caster 1 to a transport cart or the like, and has mounting holes 43 formed at its four corners for inserting connecting devices (not shown) such as bolts. In addition, a central hole 44 is formed in the center of the top plate 41 for inserting the hollow shaft portion 42. The top plate 41 holds the upper surface portion 28 of the fork 3 and the ball 29.

[0017] Multiple locking grooves 46 are formed at approximately equal intervals on the annular lower end surface 45 of the hollow shaft portion 42. The hollow shaft portion 42 is inserted through the central hole 44 of the top plate 41 and the upper surface hole 27 of the fork 3, and its upper side is crimped and fixed to the top plate 41. The lower side of the hollow shaft portion 42 sandwiches the lower surface 31 of the fork 3 and the ball 32. A dust cover 47, formed in an annular shape from synthetic resin, is disposed between the top plate 41 and the base portion 22.

[0018] The mounting base unit 4 is connected to the fork 3 via balls 29 and 32. Therefore, the fork 3 is rotatable relative to the mounting base unit 4. The wheel 2 and stopper unit 5 connected to the fork 3 are also rotatable relative to the mounting base unit 4 together with the fork 3. In other words, the wheel 2 is rotatable around a vertical axis. Hereinafter, stopping the rotation of the wheel 2 will be referred to as rotation lock, and stopping the rotation of the wheel 2 will be referred to as swivel lock. In this embodiment, the caster 1 can be locked and swivel locked simultaneously with a single operation. The state in which rotation and swivel locks are engaged is referred to as the locked state, and the state in which rotation and swivel locks are released is referred to as the unlocked state.

[0019] The stopper unit 5 includes a wheel retainer 51, a swivel stopper 52, pedal arms 53A and 53B, a pedal 54, and an identification indicator 55.

[0020] As shown in Figures 10 to 12, the wheel retainer 51 integrally comprises a plate-shaped pressing portion 61 and plate-shaped pushing portions 62A and 62B that are erected from the left and right ends of the pressing portion 61. The pushing portions 62A and 62B are pressed against the tire 12 of the wheel 2 to stop the rotation of the wheel 2. The pushing portions 62A and 62B have circular through holes, which are shaft support holes 63A and 63B. The pushing portions 62A and 62B also have support portions 64A and 64B and pushing projections 65A and 65B that engage with the swivel stopper 52 when the wheel is not locked.

[0021] As shown in Figures 13 to 15, the swivel stopper 52 integrally comprises a plate-shaped main body 71, locking claws 72A and 72B erected upward from the front end of the main body 71, and plate-shaped shaft support portions 73A and 73B erected downward from the left and right ends of the main body 71 and extending rearward.

[0022] The front portion of the main body 71 has a bifurcated shape, with locking claws 72A and 72B formed at the ends of each. The rear portion of the main body 71 has a rectangular shape that is elongated in the lateral direction (left-right direction). The locking claws 72A and 72B are formed in a rectangular plate shape and have a thickness that allows them to lock into the locking groove 46 of the mounting seat unit 4. The shaft support portions 73A and 73B are curved upward at the rear, with oval through holes, front insertion holes 74A and 74B, formed near the front end, and circular through holes, rear insertion holes 75A and 75B, formed near the rear end. The front portions of the shaft support portions 73A and 73B are connected to the main body 71.

[0023] The left pedal arm 53A and the right pedal arm 53B are identical in shape. As shown in Figures 16 to 18, the rear portions of the pedal arms 53A and 53B are bent diagonally downwards and extended. Near the front ends of the pedal arms 53A and 53B, slightly bent oval through holes, or inner shaft movement holes 81A and 81B, are formed.

[0024] Rear of the inner shaft movement holes 81A and 81B, circular through-holes, inner connecting shaft holes 82A and 82B, are formed. In addition, at the upper ends 83A and 83B of the bent portions of the pedal arms 53A and 53B, circular through-holes, outer insertion holes 84A and 84B are formed. Furthermore, near the rear ends of the pedal arms 53A and 53B, circular through-holes, inner fixing holes 85A and 85B are formed. Diagonally above the inner fixing holes 85A and 85B, rectangular through-holes, locking holes 86A and 86B are formed. Furthermore, at the lower ends 87A and 87B of the pedal arms 53A and 53B, located below the inner fixing holes 85A and 85B, concave locking grooves 88A and 88B are formed.

[0025] As shown in Figures 19 to 21, the pedal 54 integrally includes left and right fixing parts 91A and 91B that are fixed to the pedal arms 53A and 53B, and a display holding part 92 that connects the left and right fixing parts 91A and 91B.

[0026] The fixing parts 91A and 91B are opposite each other and arranged parallel to each other. Upper fixing pieces 93A and 93B are formed at the upper ends of the fixing parts 91A and 91B so as to protrude inward, and lower fixing pieces 94A and 94B are formed at the lower ends so as to protrude inward. The upper fixing pieces 93A and 93B and the lower fixing pieces 94A and 94B have a substantially rectangular shape and are formed by bending from the fixing parts 91A and 91B. In addition, the fixing parts 91A and 91B have outer fixing holes 95A and 95B which are circular through holes.

[0027] The display holding portion 92 has a connecting portion 96 that connects the fixing portion 91A and the fixing portion 91B, and a display support portion 97 that protrudes rearward from the lower end portion of the connecting portion 96. The connecting portion 96 and the display support portion 97 have a display placement hole 99 which is a roughly rectangular through hole that is long in the lateral direction (left-right direction).

[0028] As shown in Figures 22 to 24, the identification indicator fitting 55 integrally comprises a display section 101, a weight section 102, and left and right connecting pieces 103A and 103B that connect the display section 101 and the weight section 102. The display section 101 has a roughly rectangular shape that is long in the horizontal direction (left-right direction). An identification sticker 104, which indicates the locked state, is attached to the surface of the display section 101. In this embodiment, the identification sticker 104 is red, but it may be any other color as long as it is a distinguishable color, not the same color as the caster 1. Alternatively, instead of attaching the identification sticker 104 to indicate the locked state, the surface of the display section 101 may be directly colored. The width W of the display section 101 is formed to be longer than the horizontal length L of the display placement hole 98. The display section 101 constitutes a retaining mechanism that prevents the identification indicator fitting 55 from falling out of the display placement hole 98.

[0029] The weight portion 102 has a horizontal side portion 105, vertical side portions 106A and 106B protruding from the left and right ends of the horizontal side portion 105, and left and right retaining portions 107A and 107B that are located between the vertical side portions 106A and 106B and protrude from the horizontal side portion 105. The vertical side portions 106A and 106B are connected to one end of the connecting pieces 103A and 103B, and the other ends of the connecting pieces 103A and 103B are connected to the display portion 101. As shown in Figure 22, in a side view, the vertical side portions 106A and 106B and the connecting pieces are connected at an angle of approximately 75 degrees. In addition, the protrusion angles of the vertical side portions 106A and 106B and the retaining portions 107A and 107B from the horizontal side portion 105 differ by approximately 10 degrees in a side view. The retaining parts 107A and 107B abut against the display support part 97 and constitute a retaining mechanism that prevents the identification display fitting 55 from falling out of the display placement hole 98 of the display holding part 92.

[0030] The weight portion 102 is formed to be heavier than the combined weight of the display portion 101 and the connecting pieces 103A and 103B. Therefore, in the unlocked state, the identification seal 104 abuts against the connecting portion 96 of the display holding portion 92, and the identification seal 104 is held in a state where it cannot be seen from above.

[0031] Here, we will explain the connecting structure of the fork 3, the wheel retainer 51, the swivel stopper 52, the pedal arms 53A and 53B, and the pedal 54.

[0032] The shaft member 111 is inserted through the outer shaft movement holes 25A and 25B of the fork 3, the shaft support holes 63A and 63B of the wheel retainer 51, and the inner shaft movement holes 81A and 81B of the pedal arms 53A and 53B. A head 112 is formed at one end of the shaft member 111, and the head 112 is locked to the side plate portion 21B of the fork 3. A nut member 113 is screwed onto the other end of the shaft member 111, and the nut member 113 is locked to the side plate portion 21A of the fork 3.

[0033] A shaft member 114 is inserted through the outer connecting shaft holes 26A and 26B of the fork, the front insertion holes 74A and 74B of the swivel stopper 52, and the inner connecting shaft holes 82A and 82B of the pedal arms 53A and 53B. A head 115 is formed at one end of the shaft member 114, and the head 115 is locked to the side plate portion 21B of the fork 3. A nut member 116 is screwed onto the other end of the shaft member 114, and the nut member 116 is locked to the side plate portion 21A of the fork 3.

[0034] A double torsion spring 117, which acts as a biasing means, is attached to shaft members 111 and 114. The biasing force of this double torsion spring 117 holds shaft member 111 in the front position of the outer shaft movement holes 25A and 25B and the inner shaft movement holes 81A and 81B when it is in the unlocked state.

[0035] A shaft member 118 is inserted through the rear insertion holes 75A and 75B of the swivel stopper 52 and the outer insertion holes 84A and 84B of the pedal arms 53A and 53B. A head 119 is formed at one end of the shaft member 118, and the head 119 is locked to the pedal arm 53B. A nut member 120 is screwed onto the other end of the shaft member 118, and the nut member 120 is locked to the pedal arm 53A. The shaft member 118 is inserted through a cylindrical reinforcing body 121. The left and right portions of the reinforcing body 121 are inserted through the rear insertion holes 75A and 75B and are in contact with the pedal arms 53A and 53B.

[0036] A screw member 123A is inserted through the inner fixing hole 85A of the pedal arm 53A and the outer fixing hole 95A of the pedal 54, and is screwed into a nut member 122A that is locked to the inner surface of the pedal arm 53A. Similarly, a screw member 123B is inserted through the inner fixing hole 85B of the pedal arm 53B and the outer fixing hole 95B of the pedal 54, and is screwed into a nut member 122B that is locked to the inner surface of the pedal arm 53B.

[0037] When screwing the screw members 123A and 121B together with the nut members 122A and 122B, the upper fixing piece 93A of the pedal 54 is inserted through the locking hole 86A of the pedal arm 53A, and the lower fixing piece 94A of the pedal 54 is locked into the locking groove 88A of the pedal arm 53A. Also, the upper fixing piece 93B of the pedal 54 is inserted through the locking hole 86B of the pedal arm 53B, and the lower fixing piece 94B of the pedal 54 is locked into the locking groove 88B of the pedal arm 53B.

[0038] In this way, the fork 3, the wheel retainer 51, the swivel stopper 52, the pedal arms 53A, 53B, and the pedal 54 are connected by the shaft members 111, 114, 118, the screw members 123A, 121B, and the nut members 113, 116, 120, 122A, 122B.

[0039] Next, the method of using the caster 1 will be explained. As shown in Figure 1, when the pedal 54 is pressed down with a foot or the like when it is in the unlocked state, the axle member 111 moves toward the rear of the outer axle movement holes 25A, 25B and the inner axle movement holes 81A, 81B against the biasing force of the double torsion spring 117. At this time, the wheel retainer 51, which is pivotally supported on the axle member 111, also moves backward together with the axle member 111. When the wheel retainer 51 moves backward, the push-up projections 65A, 65B of the wheel retainer 51 enter below the main body 71 of the swivel stopper 52, lifting the main body 71. Furthermore, when the pedal 54 is pushed in (pressed down), the shaft member 111 moves to the rearmost part of the outer shaft movement holes 25A, 25B and the inner shaft movement holes 81A, 81B, the rear portions of the pedal arms 53A, 53B are lifted upward, lifting the main body 71, and the locking claws 72A, 72B engage with the locking groove portion 46 of the hollow shaft portion 42, thereby stopping the rotation of the wheel 2, fork 3 and stopper unit 5. At this time, the wheel retainer 51 separates from the swivel stopper 52, and the pressing portion 61 of the wheel retainer 51 presses against the tire 12, stopping the rotation of the wheel 2. Also, the weight portion 102 of the identification indicator 55 is pushed up by the tire 12 and held in a state of being pressed against the tire 12. In this state, the display portion 101 of the identification indicator 55 is positioned above the display support portion 97 of the pedal 54, and the identification sticker 104 becomes visible from above. This state is the locked state. When the pedal is locked, lifting pedal 54 upwards with your foot or other object will simultaneously release the lock.

[0040] As described above, the caster 1 of this embodiment comprises a wheel 2, a fork 3 that rotatably holds the wheel 2, a mounting seat unit 4 attached to the upper part of the fork 3, and a stopper unit 5 attached to the fork 3 that stops the rotation of the wheel 2 and the swivel of the fork 3. The fork 3 is swivelable relative to the mounting seat unit 4. The stopper unit 5 includes a wheel retainer 51 that presses against the wheel 2 to stop its rotation, a swivel stopper 52 that engages with the mounting seat unit 4 to stop the swivel of the fork 3, a pedal 54 for operating the stopper unit 5, and pedal arms 53A and 53B that transmit the power of the operated pedal 54 to the wheel retainer 51 and the swivel stopper 52. When the pedal 54 is pressed, the wheel retainer 51 presses against the wheel 2 and the swivel stopper 52 engages with the mounting seat unit 4. Therefore, with a single operation of pressing the pedal 54, the rotation of the wheel 2 and the swivel of the fork 3 can be stopped simultaneously.

[0041] Furthermore, in this embodiment, the caster 1 has side axle movement holes 25A and 25B formed in the fork 3 through which the axle member 111 is inserted, and inner axle movement holes 81A and 81B formed in the pedal arms 53A and 53B through which the axle member 111 is inserted. The wheel retainer 51 is pivotally supported by the axle member 111. When the wheel 2 is locked and the fork 3 is stopped from rotating, the axle member 111 is located on one side of the outer axle movement holes 25A and 25B and the inner axle movement holes 81A and 81B. When the wheel 2 is rotatable and the fork 3 is pivotable, the axle member 111 is located on the other side of the outer axle movement holes 25A and 25B and the inner axle movement holes 81A and 81B. Therefore, by moving the axle member 111 between the outer axle movement holes 25A and 25B and the inner axle movement holes 81A and 81B, the position of the wheel retainer 51 pivotally supported by the axle member 111 can be changed. Then, the position of the wheel retainer 51 changes, which switches between the locked and unlocked states of the wheel 2 and the fork 3.

[0042] Furthermore, in this embodiment, the caster 1 has a mounting base unit 4 with a locking groove 46, and the swivel stopper 52 has locking claws 72A and 72B that engage with the locking groove 46. The swivel stopper 52 is pivotally supported on the fork 3 by shaft members 114 and 118, and when the swivel stopper 52 is pressed upward by the fork 3, the locking claws 72A and 72B engage with the locking groove 46. Therefore, the fork 3 can be locked by engaging the locking claws 72A and 72B with the locking groove 46.

[0043] Furthermore, in this embodiment, the caster 1 has an axle member 111 biased by a double torsion spring 117, which biases the axle member 111 to move in the direction of moving it to the other side of the outer axle movement holes 25A, 25B and the inner axle movement holes 81A, 81B. Therefore, when the wheel 2 and fork 3 are unlocked, the axle member 111 is held in the outer axle movement holes 25A, 25B and the other side (rear) of the inner axle movement holes 81A, 81B. In other words, when the wheel 2 and fork 3 are unlocked, the axle member 111 is held in a fixed position, and the wheel retainer 51, swivel stopper 52, pedal arms 53A, 53B, and pedal 54 are also held in a fixed position.

[0044] Furthermore, in this embodiment, the caster 1 has an identification indicator 55 attached to the pedal 54. The identification indicator 55 has an identification seal 104 that indicates that the rotation of the wheel 2 and the swivel of the fork 3 are stopped, and the identification seal 104 is visible from above when the wheel 2 and fork 3 are locked, and not visible from above when the wheel 2 and fork 3 are unlocked. Therefore, the locked state of the wheel 2 and fork 3 can be seen at a glance.

[0045] Furthermore, in this embodiment, the caster 1 has an identification indicator 55 inserted through a display placement hole 98 formed in the pedal 54. The identification indicator 55 has a weight portion 102 that is positioned downward by its own weight when the wheel 2 and fork 3 are unlocked, and a display portion 101 and retaining portions 107A and 107B that prevent it from falling out of the display placement hole 98. Therefore, when the wheel 2 and fork 3 are unlocked, the identification indicator 55 is held in a predetermined position. In addition, it is possible to prevent the identification indicator 55 from falling out of the display placement hole 98.

[0046] It should be noted that the present invention is not limited to the embodiments described above, and various modifications can be implemented within the scope of the gist of the invention. For example, this locking structure can also be applied to casters with different wheel sizes (diameters). [Explanation of Symbols]

[0047] 1 caster 2 wheels 3 forks 4. Mounting base unit 5 Stopper Unit 25A Outer shaft movement hole (first elongated hole) 25B External axis moving hole (first elongated hole) 46 Locking groove 51 Wheel retainer 52 Swivel stopper 53 Pedal Arm 54 pedals 55 Identification Marking Devices 72A Locking claw part 72B Locking claw part 81A Inner shaft movement hole (second elongated hole) 81B Inner axial movement hole (second elongated hole) 91A Fixed part 91B Fixed part 92 Display holding part 98 Display placement hole 101 Display unit (retaining mechanism) 102 Weight 104 Identification sticker (label) 107A Retaining part (retaining mechanism) 107B Retaining part (retaining mechanism) 111 Shaft member (first shaft member) 114 Shaft member (second shaft member) 117 Double torsion spring (biasing means) 118 Shaft member (third shaft member)

Claims

1. Wheels and, A fork that rotatably holds the wheel, A mounting base unit attached to the upper part of the fork, The system includes a stopper unit attached to the fork to stop the rotation of the wheel and the swivel of the fork, The fork is rotatable relative to the mounting base unit, The stopper unit comprises a wheel retainer that presses against the wheel to stop its rotation, a swivel stopper that engages with the mounting seat unit to stop the fork from swiveling, a pedal for operating the stopper unit, and a pedal arm that transmits the power of the operated pedal to the wheel retainer and the swivel stopper. The pedal has a pair of left and right fixing parts fixed to the pedal arm, and a display holding part connecting the left and right fixing parts. When viewed from above, the wheels are visible between the left and right fixing parts, and the display holding part is located behind the wheels. A caster characterized in that when the pedal is pressed, the wheel retainer presses against the wheel and the swivel stopper locks into the mounting base unit.

2. The fork has a first elongated hole through which a first shaft member is inserted. The pedal arm has a second elongated hole through which the first shaft member is inserted. The wheel retainer is pivotally supported by the first shaft member, When the rotation of the wheel and the rotation of the fork are stopped and the wheel is locked, the first shaft member is positioned in the first elongated hole and on one side of the second elongated hole. The caster according to claim 1, characterized in that when the wheel is in an unlocked state in which it is rotatable and the fork is in a pivotable state, the first shaft member is located in the first elongated hole and on the other side of the second elongated hole.

3. The first shaft member is biased by a biasing means, The caster according to claim 2, characterized in that the biasing means biases the first shaft member in a direction that moves it in the first elongated hole and to the other side of the second elongated hole.

4. An identification indicator is attached to the aforementioned pedal. The identification indicator has an indicator that the rotation of the wheel and the rotation of the fork are stopped and the device is locked. The caster according to claim 1, characterized in that the indicator is visible from above when the wheel is locked and not visible from above when the wheel is rotatable and the fork is pivotable.

5. The identification indicator is inserted through a display placement hole formed in the pedal. The caster according to claim 4, characterized in that the identification indicator has a weight portion that is positioned on the lower side by its own weight when the wheel and the fork are in an unlocked state, and a retaining portion that prevents it from falling out of the indicator placement hole.

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