Caster device

Abstract

To provide a caster device that contributes to improvement of durability.SOLUTION: A caster device includes a braking mechanism. The braking mechanism has an engaged section 17 provided in a wheel 16, a brake 18 which can be displaced between a lock position at which the wheel 16 is locked and a lock release position, a first coil spring 22 for energizing the brake 18, a braking lever 28 which is in communication with the brake body 18 and can be displaced between a horizontal position where the brake body 18 is positioned at the lock release position and an inclined position, a second coil spring 26 for energizing the braking lever 28, and a wire 7 for applying operational force to the braking lever 28. A connection section of the brake lever 28 has a relief section 292 that allows relative displacement of the brake 18 with respect to the braking lever 28 when the brake 18 makes contact with a partition wall section 17b of the engaged section 17 in a process of displacement of the braking lever 28 from the horizontal position to the inclined position.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a caster device that is attached to a movable object such as furniture, a chair, or a cart. [Background technology]

[0002] An example of such a caster device is disclosed in Patent Document 1. This caster device includes a wheel with multiple grooves arranged inwardly in the circumferential direction around the axle, a braking body (brake block) that is inserted into the groove and can be displaced between a locking position that locks the rotation of the wheel and an unlocking position that unlocks the wheel, a spring member that urges the braking body toward the locking position, and an operating member (wire) that displaces the braking body from the locking position to the unlocking position against the urging force of the spring member.

[0003] According to this caster braking device, when the operating member is not operated, the braking body is placed in the locked position by the biasing force of the spring member. This locks the rotation of the wheels. On the other hand, when the operating member is operated, the braking body is displaced from the locked position to the unlocked position, allowing the rotation of the wheels. This makes it possible to move the mobile object.

[0004] In addition, a similar caster device has been considered that is configured to displace the brake body from an unlocked position to a locked position when an operating member is operated by moving the brake body via a cam member. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2010-228756 A Summary of the Invention [Problem to be solved by the invention]

[0006] In the conventional caster device as described above, if the positions of the brake body and the groove are not correctly matched, the brake body may hit the partition between adjacent grooves, and the brake body may not be able to move to the locked position. Therefore, particularly in the case of a caster device in which the brake body is moved from the unlocked position to the locked position by operating an operating member, the operating member may be forcibly operated in a state in which the brake body hits the partition, and as a result, the mechanism parts such as the cam member and the brake body may be damaged. Therefore, it is desirable to improve this point and improve the durability of the caster device.

[0007] The present invention has been made in consideration of the above-mentioned circumstances, and aims to provide a technology that contributes to improving the durability of caster devices. [Means for solving the problem]

[0008] In order to solve the above problems, a caster device according to one aspect of the present invention is a caster device that is attached to an object to be moved, and includes a wheel that rotates around an axle and a braking mechanism that locks the rotation of the wheel, the braking mechanism having an engaged portion that is provided on the wheel and has a plurality of grooves that are aligned in a circumferential direction around the axle, and an engaging portion that engages with the engaged portion by being inserted into the groove, the engaging portion engaging with the engaged portion and displaceable between a locked position where the engaging portion engages with the engaged portion to lock the rotation of the wheel and an unlocked position where the rotation of the wheel is permitted, a first biasing member that biases the brake body toward the locked position, and a connecting portion that is connected to the brake body, The brake lever comprises a lever member that is displaceable between a first position at which the brake body is placed in the released position and a second position at which the brake body can be placed in the locked position, a second biasing member that biases the lever member toward the first position with a biasing force greater than the biasing force of the first biasing member, and an operating member that applies an operating force to the lever member to displace the lever member from the first position to the second position, and is characterized in that the connecting portion is provided with an escape portion that allows the engaging portion to be displaced relative to the lever member when the engaging portion abuts against a partition portion between a pair of adjacent grooves during the process of the lever member being displaced from the first position to the second position.

[0009] In this caster device, when no operating force is applied to the lever member by the operating member, the lever member is held in the first position by the biasing force of the second biasing member, and the brake body is held in the unlocked position against the biasing force of the first biasing member. This allows the wheel to rotate, making it possible to move the object to be moved.

[0010] On the other hand, when an operating force is applied to the lever member by the operating member and the lever member is displaced to the second position against the biasing force of the second biasing member, the brake body is displaced from the unlocked position to the locked position by the biasing force of the first biasing member in accordance with this displacement. When the brake body is completely displaced to the locked position, the rotation of the wheel is locked and the movement of the moving object is disabled. In this way, during the process of displacing the brake body from the unlocked position to the locked position, the engaging portion may come into contact with the partition portion between a pair of adjacent grooves, and the engaging portion may not be inserted into the groove of the engaged portion. Therefore, if the operating force is continuously applied in this state, in the worst case, the braking mechanism may be damaged.

[0011] However, according to the caster device, the relief portion is provided, and even if the operating force is continuously applied with the engaging portion in contact with the partition portion of the engaged portion, the engaging portion is displaced relative to the lever member and escapes to the relief portion, thereby suppressing or preventing damage to the braking mechanism. Therefore, the caster device can contribute to improving the durability.

[0012] In the above caster device, the engagement portion of the braking body has an axis portion extending parallel to the axle, the lever member is arranged to be swingable around the axle or an axis parallel to the axle, and is equipped with a guide portion that guides the braking body from the unlocked position to the locked position via the axis portion, the connecting portion includes the guide portion, and the escape portion is configured to allow the axis portion to be displaced relative to the connecting portion when the axis portion abuts against the partition portion.

[0013] According to this configuration, the lever member is displaced between a first position and a second position by swinging about the axle or an axis parallel to the axle. As the lever member is displaced from the first position to the second position, the brake body is guided from the unlocked position to the locked position via the shaft portion (engagement portion). At this time, even if the operating force is continuously applied with the shaft portion (engagement portion) abutting against the partition portion of the engaged portion, the shaft portion displaces relative to the lever member and escapes to the escape portion, thereby suppressing or preventing damage to the braking mechanism.

[0014] As a more specific configuration, the guide portion may consist of a hole portion or a notch-shaped portion into which the shaft portion is inserted, and the escape portion may consist of a portion of the hole portion or the notch-shaped portion formed to expand.

[0015] According to this configuration, as the lever member is displaced from the first position to the second position, the brake body is displaced from the unlocked position to the locked position while being guided by the guide portion consisting of a hole or a notch-shaped portion via the shaft portion (engagement portion). When the operating force is continuously applied with the shaft portion in contact with the partition portion of the engaged portion, the shaft portion is displaced to a portion (relief portion) formed so as to expand a part of the hole or the notch-shaped portion.

[0016] In addition, the above caster device may be configured to include a caster main body that is attached to the object to be moved, and the wheel, the braking body, the first biasing member, the lever member, the second biasing member and the operating member are assembled to the caster main body.

[0017] According to this configuration, a compact (space-efficient) configuration is achieved in which the caster main body serves as a core component and the braking mechanism is assembled to the caster main body.

[0018] In this case, the caster device may be configured to include a connecting shaft that connects the caster main body to the object to be moved so that the caster main body can rotate about a vertical axis.

[0019] According to this configuration, it is possible to rotate the wheels about a vertical axis, and it is therefore possible to easily change the orientation of the wheels, and therefore the direction of movement of the object to be moved.

[0020] In addition, in the above-mentioned caster device, the wheels may be provided on both sides of the caster main body via the axle, and the braking body may be configured to have an engaging portion that is capable of engaging with the engaged portion provided on each wheel.

[0021] According to this configuration, since one caster device is provided with two wheels, the support stability of the moving object is improved. Moreover, it is possible to switch between locking and unlocking the rotation of the two wheels with one braking body. Effect of the Invention

[0022] The caster device of the present invention as described above contributes to improving its durability. [Brief description of the drawings]

[0023] [Figure 1] 1 is a perspective view of a table to which a caster (caster device) according to the present invention is applied. [Diagram 2] FIG. [Diagram 3] FIG. [Figure 4] FIG. 4 is a cross-sectional view of the caster (a cross-sectional view taken along line IV-IV in FIG. 2). [Diagram 5] 13 is a cross-sectional view of the caster showing the movement of the braking mechanism (when the stopper shaft does not abut against the partition portion). FIG. [Figure 6] 13 is a cross-sectional view of the caster showing the movement of the braking mechanism (when the stopper shaft abuts against the partition portion). FIG. [Figure 7] 13 is a cross-sectional view of a caster of a reference example showing the movement of the braking mechanism when the braking lever does not have an escape portion. [Figure 8] 5 is a cross-sectional view of a caster according to a modified example (corresponding to FIG. 4). FIG. [Figure 9] 11 is a cross-sectional view of a caster showing the movement of the braking mechanism of the caster according to a modified example. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[0025] Fig. 1 is a perspective view of a table 1 to which the caster device according to the present invention is applied. The table 1 shown in the figure includes a top board 2, four legs 4a-4d fixed to the underside of the top board, and casters 5a-5d (caster devices) fixed to the lower ends of the legs 4a-4d, respectively. The top board 2 is rectangular in plan view, and the legs 4a-4d are arranged at its four corners.

[0026] A braking mechanism, which will be described later, is incorporated in each of the casters 5a to 5d. The braking mechanism is a mechanism that switches the casters 5a to 5d between a state in which the rotation of the wheels 16, which will be described later, is locked (rotation locked state) and a state in which the lock is released and the rotation is permitted (unlocked state). By setting the casters 5a to 5d to the rotation locked state, the table 1 can be fixedly positioned at a fixed position, while by setting the casters 5a to 5d to the unlocked state, the table 1 can be moved along the floor surface.

[0027] A swingable switching lever 6 for switching between a rotation locked state and an unlocked state is provided on the side of the back panel 3 of the table 1. Wires 7a-7b are connected to the switching lever 6, which are respectively routed inside the legs 4a-4d and the back panel 3 and have one end connected to the casters 5a-5d. The other ends of the wires 7a-7d are gathered together in a connecting box (not shown) and connected to the switching lever 6. This configuration makes it possible to simultaneously switch the casters 5a-5d as described above by operating one switching lever 6.

[0028] In this example, as shown in FIG. 1, the casters 5a-5d can be switched from an unlocked state to a rotation-locked state by swinging (rotating) the switch lever 6 180° in the direction of arrow R1 from the state along the underside of the tabletop 2, and the casters 5a-5d can be switched from the rotation-locked state to the original unlocked state by swinging the switch lever 6 180° in the opposite direction (the direction of arrow R2).

[0029] [Detailed configuration of casters 5a to 5d] Next, the configuration of the casters 5a to 5d will be described. Since the casters 5a to 5d have the same configuration, in the following description, unless otherwise necessary, the casters 5a to 5d will not be distinguished from each other and will be referred to as "caster 5". Similarly, the wires 7a to 7d and the legs 4a to 4d of the table 1 will be referred to as "wire 7" and "leg 4".

[0030] Fig. 2 is a front view of the caster 5, and Fig. 3 is an exploded perspective view of the caster 5. Also, Fig. 4 is a cross-sectional view of the caster 5 (a cross-sectional view taken along line IV-IV in Fig. 2).

[0031] As shown in Figures 2 to 4, the caster 5 includes a main shaft 10 (connecting shaft) extending in the vertical direction, a frame 12 (caster main body) fitted to this main shaft 10, and a wheel 16 and a braking mechanism assembled to this frame 12 via an axle 14.

[0032] The main shaft 10 has a flange 11a provided at a position near the upper end thereof, and an upper shaft portion 11c above the flange 11a and a lower shaft portion 11b below the flange 11a. The upper shaft portion 11c of the main shaft 10 is fitted into a recess (hole) formed in the lower end surface of the leg 4, thereby fixing the caster 5 to the leg 4.

[0033] The frame 12 is an assembly base for the wheels 16 and the braking mechanism. The frame 12 is a roughly semicircular member with a curved upper side in a side view (as viewed in the axial direction of the axle 14) that has a thickness in the axial direction of the axle 14, and is made of a material such as a synthetic resin having a relatively high rigidity. The frame 12 is formed with a through hole 12a that penetrates in its thickness direction (hereinafter, sometimes referred to as the width direction or the left-right direction), and the axle 14 is inserted into this through hole 12a. The axle 14 is fixed to the frame 12 by, for example, being pressed into the through hole 12a, and is arranged horizontally with the casters 5 attached to the legs 4 of the table 1. The wheels 16 are rotatably supported at both ends of the axle 14, so that the wheels 16 are arranged on both sides of the frame 12 in the width direction.

[0034] A through hole 12b that penetrates in the vertical direction is formed in the frame 12 at a position adjacent to one side (the right side in FIG. 4) of the through hole 12a (axle 14). The lower shaft portion 11b of the main shaft 10 is fitted into this through hole 12b, thereby fixing the frame 12 to the main shaft 10. The lower shaft portion 11b of the main shaft 10 is configured to be rotatable about the axis of the main shaft 10 relative to the other portions (the flange portion 11a and the lower shaft portion 11b). Therefore, the caster 5 is rotatable about the axis of the main shaft 10 relative to the leg 4.

[0035] As shown in FIG. 4, in the following description, for convenience, the side of the main shaft 10 when viewed from the axle 14 is referred to as the “rear” of the caster 5, and the side opposite the main shaft 10 is referred to as the “front” of the caster 5.

[0036] As described above, the braking mechanism is a mechanism for switching the caster 5 between a rotation locked state in which the rotation of the wheel 16 is locked, and an unlocked state in which the lock is released and rotation is permitted. The braking mechanism includes braking bodies 18 provided so as to be engageable with and detachable from the wheels 16, engaged portions 17 of the braking bodies 18 provided on each wheel 16, braking levers 28 (lever members) for controlling the position of the braking bodies 18, and the wire 7 (operating member) for operating the braking levers 28.

[0037] The brake body 18 is disposed below the frame 12 and adjacent to the front side (left side in FIG. 4) of the through hole 12a (axle 14). More specifically, the brake body 18 is disposed below the frame 12 with a portion of the brake body 18 inserted into a recess 12d formed in the lower surface of the frame 12 facing upward.

[0038] The brake body 18 is composed of a brake arm 19 and a stopper shaft 24 (engagement portion / shaft portion) that is held by the brake arm 19 and has a circular cross section and extends in the width direction. The brake arm 19 is a block-shaped member that is elongated in the front-rear direction and has a rectangular shape in a plan view, and is made of synthetic resin or the like. At both front and rear ends of the brake arm 19, through holes 19a, 19b that penetrate in the width direction are formed, and the stopper shaft 24 is fitted into the rear through hole 19b. The stopper shaft 24 is disposed in parallel with the axle 14. The entire length of the stopper shaft 24 is longer than the thickness (width) of the frame 12, and both ends of the stopper shaft 24 protrude outward in the width direction from the frame 12 and are inserted into the recesses 161 described below of each wheel 16.

[0039] The front end of the brake arm 19 is disposed in the recess 12d of the frame 12, and is journaled in this recess 13 at a position near the front end of the frame 12. More specifically, a spring pin 20 is inserted between a through hole 12c formed in the left and right walls of the recess 12d and the through hole 19a of the brake arm 19. With this configuration, the brake body 18 is journaled to the frame 12 so as to be able to swing freely, with the front end of the brake arm 19 as a fulcrum.

[0040] A first coil spring 22 (first biasing member) made of a compression coil spring is interposed in a compressed state between the ceiling portion of the recess 12d of the frame 12 and the brake arm 19. With this configuration, the brake body 18, more specifically, the stopper shaft 24 is biased in a direction away from the axle 14, i.e., toward the engaged portion 17.

[0041] 3, in each wheel 16, a surface facing the frame 12 is formed with an annular recess 161 recessed toward the side opposite the frame 12. The engaged portion 17 is provided on the inner peripheral surface of this annular recess 161, i.e., the peripheral surface facing the wheel 16.

[0042] The engaged portion 17 is composed of a plurality of grooves (recesses) 17a that open toward the axle 14 and are arranged at equal intervals in the circumferential direction, and partitions 17b formed between adjacent grooves 17a. The grooves 17a have a U-shaped cross section when viewed in the axial direction of the axle 14.

[0043] As described above, both ends of the stopper shaft 24 in the brake body 18 are inserted into the recesses 161 of the wheel 16. The end of the stopper shaft 24 is inserted into the groove 17a and the stopper shaft 24 engages with the engaged portion 17, thereby locking the rotation of the wheel 16. On the other hand, when the end of the stopper shaft 24 is disposed outside the groove 17a and the engagement between the stopper shaft 24 and the engaged portion 17 is released, the rotation of the wheel 16 is permitted. In other words, the brake body 18 is provided so as to be displaceable between a locked position (see FIG. 5(C)) where the stopper shaft 24 engages with the engaged portion 17 to lock the rotation of the wheel 16, and an unlocked position (position in FIG. 4) where the rotation of the wheel 16 is permitted, and is biased toward the locked position by the elastic force (biasing force) of the first coil spring 22.

[0044] The brake lever 28 is a press-formed member made of a metal plate. As shown in Figs. 3 and 4, the brake lever 28 has a U-shaped cross section that opens upward, and includes side plate portions 281 that are aligned with the left and right side surfaces of the frame 12, and a bottom plate portion 282 that connects the lower ends of the both side plate portions 281. A through hole 29a that penetrates the side plate portions 281 in the thickness direction (width direction) is formed in the center of each side plate portion 281 in the front-rear direction. The brake lever 28 is supported so as to be swingable around the axis of the axle 14 with the frame 12 sandwiched between the left and right side plate portions 281 by inserting the axle 14 into the through hole 29a of the side plate portions 281.

[0045] The side plate portions 281 extend to both the front and rear sides with the through hole 29a (axle 14) as the center, and the bottom plate portion 282 connects the portions of the side plate portions 281 that are roughly rearward of the through hole 29a. The portions of the side plate portions 281 that are forward of the through hole 29a are each formed with a guide hole 29b that penetrates the side plate portions 281 in the thickness direction (width direction). The guide hole 29b is a guide portion that guides the brake body 18 via the stopper shaft 24. As shown in FIG. 2, the stopper shaft 24 extends in the width direction through the guide hole 29b of the left and right side plate portions 281, and as described above, both ends thereof are inserted into the recesses 161 of the wheels 16.

[0046] The brake lever 28 is connected to the brake body 18 by the stopper shaft 24 extending through the guide hole 29b in this manner. That is, the portion of the brake lever 28 that is in front of the through hole 29a is a connecting portion that is connected to the brake body 18, and this connecting portion includes the guide hole 29b that is a guide portion for the brake body 18 as described above.

[0047] Brake lever 28 is capable of swinging between a horizontal position (position shown in FIG. 4 / "first position") in which bottom plate portion 282 is substantially perpendicular to the axis of spindle 10, and an inclined position (see FIG. 5(c) / "second position") in which the portion forward of spindle 10 is inclined downward. Guide hole 29b is formed to guide brake body 18 between the unlocked position and the rotation locked position as brake lever 28 swings.

[0048] Specifically, as shown in an enlarged view within a dashed-dotted circular frame in Fig. 4, the guide hole 29b is formed in a generally triangular shape with an elongated hole (sometimes referred to as elongated hole 291 / partially shown by imaginary lines in Fig. 4) having a width slightly larger than the diameter of the stopper shaft 24 and extending in the front-rear direction as a base, and an expansion portion 292 that expands the elongated hole 29 upwardly provided. As described above, since the brake body 18 is biased by the first coil spring 22, the stopper shaft 24 is guided along the lower side of the generally triangular guide hole 29b as the brake lever 28 swings. This causes the brake body 18 to displace between the unlocked position and the rotation locked position.

[0049] The expanded portion 292 of the guide hole 29b is a portion for allowing the stopper shaft 24 to escape depending on the situation when the brake body 18 is displaced from the unlocked position to the locked position, and this point will be described in detail later. In the following description, the expanded portion 292 is referred to as the "escape portion 292."

[0050] Of the brake lever 28, the bottom plate portion 282 faces the underside of the frame 12 at the position of the main shaft 10. A second coil spring 26 (second biasing member) made of a compression coil spring is interposed in a compressed state between the underside of the frame 12 and the brake lever 28a. In detail, a countersink 13 is formed around the through hole 12b on the underside of the frame 12, and the second coil spring 26 is interposed between the back end surface of the countersink 13 and the bottom plate portion 282 with the lower end of the main shaft 10 inserted inside.

[0051] The spring force of the second coil spring 26 is set to be greater than the spring force of the first coil spring 22. In other words, the spring constant of the second coil spring 26 is set to be greater than the spring constant of the first coil spring 22. With this configuration, the brake lever 28 is held in the horizontal position shown in Fig. 4 against the spring force of the first coil spring 22 that biases the brake body 18. When the brake lever 28 is in the horizontal position, the brake body 18 is pushed upward via the stopper shaft 24 as shown in Fig. 4, and is thereby restrained in the unlocked position.

[0052] As shown in Fig. 3, a slit-shaped through hole 29c that penetrates in the vertical direction is formed in the bottom plate portion 282 of the brake lever 28. The wire 7 is inserted into this through hole 29c. The wire 7 penetrates the bottom plate portion 282, and extends into the leg 4 through the inside of the second coil spring 26 and the passage 10a in the main shaft 10. A stopper 70 is provided at the end of the wire, and the end of the wire 7 is engaged with the bottom plate portion 282 via this stopper 70.

[0053] As described above, the wires 7 are gathered together in a connection box and connected to the switching lever 6. When the switching lever 6 is swung, the braking mechanism switches between a rotation locked state and an unlocked state of the caster 5.

[0054] [Operation and effect of braking mechanism] Next, there will be described the operation and effects of the braking mechanism of the caster 5. Fig. 5 is a cross-sectional view of the caster 5 showing the operation of the braking mechanism, and shows the time-series movement from the unlocked state to the rotation locked state.

[0055] When the switching lever 6 is in the position shown in Fig. 1, the caster 5 is in an unlocked state. That is, as shown in Fig. 5(a), the braking lever 28 is held in a horizontal position by the biasing force of the second coil spring 26, and the braking body 18 is thus disposed in the unlocked position.

[0056] When the switch lever 6 is operated in the R1 direction (see Figure 1) from this state, the rear end (bottom plate portion 282) of the brake lever 28 is pulled up via the wire 7, and as shown in Figures 5(b) and 5(c), the brake lever 28 is displaced from the horizontal position to an inclined position against the stepped force of the second coil spring 26. In conjunction with this displacement of the brake lever 28, the brake body 18 is displaced from the unlocked position to the rotation locked position due to the stepped force of the first coil spring 22.

[0057] Here, when the position of the engaged portion 17 of the wheel 16 corresponds (matches) with the position of the stopper shaft 24 of the brake body 18, specifically, when the groove portion 17a of the engaged portion 17 is on the movement path of the stopper shaft 24, as the brake lever 28 swings, the stopper shaft 24 is inserted into the groove portion 17a while being guided along the lower side of the guide hole 29b, as shown in Figs. 5(a) to (c). This causes the brake body 18 to shift from the unlocked position to the rotation locked position. In other words, the brake body 18 engages with the engaged portion 17 via the stopper shaft 24, thereby locking the rotation of the wheel 16.

[0058] On the other hand, when the position of the engaged portion 17 of the wheel 16 does not correspond (match) with the position of the stopper shaft 24 of the brake body 18, that is, when the partition wall 17b between the adjacent grooves 17a is present on the movement path of the stopper shaft 24, the following movement occurs. As shown in Fig. 6(a), as the brake lever 28 swings from the horizontal position to the inclined position, the stopper shaft 24 abuts against the partition wall 17b, thereby restricting (preventing) the displacement of the brake body 18. However, as the brake lever 28 swings further, the stopper shaft 24 is displaced relatively to the position of the relief portion 292 of the guide hole 29b, and as a result, the brake lever 28 is displaced to the completely inclined position as shown in Figs. 6(b) and (c).

[0059] In the state shown in Fig. 6(c), the brake lever 28 is displaced to the completely tilted position, but the stopper shaft 24 is not inserted into the groove 17a, and the brake body 18 has not reached the rotation lock position. In this case, when the wheel 16 is rotated slightly relative to the brake lever 28 by pushing or pulling the table 1 as shown in Fig. 6(d), the position of the stopper shaft 24 is shifted in the circumferential direction from the partition wall 17b. As a result, the stopper shaft 24 is displaced by the biasing force of the first coil spring 22 and inserted into the groove 17a, and the brake body 18 is disposed in the rotation lock position.

[0060] In this caster 5, as described above, when the stopper shaft 24 abuts against the partition portion 17b, the stopper shaft 24 is relatively displaced to the position of the escape portion 292 of the guide hole 29b, thereby preventing damage to the braking mechanism when the caster 5 is switched from the unlocked state to the rotation locked state.

[0061] For example, as shown in FIG. 7(a), assume that the guide hole 29b of the brake lever 28 in the caster 5 is shaped as the long hole 291 as described above (without the escape portion 292). In this case, even if the stopper shaft 24 abuts against the partition wall portion 17b as shown in FIG. 7(b) while the brake lever 28 is swinging from the horizontal position to the inclined position, the stopper shaft 24 has no escape route. That is, since the brake lever 28 cannot be displaced relative to the stopper shaft 24, the displacement of the brake lever 28 is restricted (prevented) before it reaches the completely inclined position. Therefore, if the switching lever 6 is continuously (forcibly) operated in such a state, it is considered that the engaged portion 17 of the wheel 16 may be damaged, the stopper shaft 24 or the brake lever 28 may be deformed, the wire 7 may be broken, or the like may be caused.

[0062] However, according to the configuration of the caster 5, in which the escape portion 292 is provided in the guide hole 29b of the brake lever 28, as described above, even if the switch lever 6 is continuously (forcibly) operated when the stopper shaft 24 is in contact with the partition portion 17b, that is, when the brake lever 28 is not displaced to the fully inclined position, damage to the brake mechanism is effectively prevented.

[0063] 1, the wire 7 is loosened, and the brake lever 28 is displaced from the inclined position to the horizontal position by the stepped force of the second coil spring 26. With this displacement of the brake lever 28, the brake body 18 is displaced from the rotation locked position to the unlocked position against the stepped force of the first coil spring 22.

[0064] As described above, according to the caster 5, damage to the braking mechanism during switching from the unlocked state to the rotation locked state is effectively suppressed. This can contribute to improving the durability of the caster 5.

[0065] In particular, as described above, in a configuration in which a pair of left and right wheels 16 that rotate independently are provided and the rotation lock and unlock of these wheels 16 are switched by a single (common) brake body 18, the stopper shaft 24 is often not inserted into the left and right grooves 17a at the same time when switching from the unlocked state to the rotation locked state. In other words, during the switching operation, a situation is likely to occur in which the stopper shaft 24 is inserted into the groove 17a for one wheel 16 and the stopper shaft 24 abuts against the partition wall 17b for the other wheel 16, and there is a concern that the braking mechanism may be damaged during the switching operation. However, the caster 5 solves such a problem.

[0066] [Modifications, etc.] The caster 5 described above is an example of a preferred embodiment of the caster device according to the present invention, and the specific configuration of the caster 5 can be appropriately changed without departing from the scope of the present invention. For example, the following configurations are also within the scope of the present invention.

[0067] (1) In the embodiment, compression coil springs (first coil spring 22, second coil spring 26) are used as the biasing members for biasing the brake body 18 and the brake lever 28. However, the biasing members are not limited to compression coil springs. For example, other springs such as a torsion coil spring, a spiral spring, or a leaf spring may also be used.

[0068] 8 shows an example in which a leaf spring 40 is used as a biasing member for biasing the brake body 18, instead of the first coil spring 22. As shown in the figure, the leaf spring 40 has a flat base portion 40a fixed to the bottom plate portion 282 of the brake lever 28 and a flexible piece portion 40b extending forward from the front end thereof and capable of being flexibly displaced, and the brake body 18 (brake arm 19) is biased in a direction away from the axle 14 by the flexible piece portion 40b.

[0069] With this configuration, as shown in Figures 9(a) and (b), it is possible to bias the brake body 18 in the same way as with the caster 5 of the embodiment. Figure 9 is a cross-sectional view showing the movement of the braking mechanism of the caster 5, where (a) shows a state in which the stopper shaft 24 abuts against the partition wall 17b of the engaged part 17 as the brake lever 28 swings, and the stopper shaft 24 is relatively displaced to the position of the relief part 292 of the guide hole 29b, and (b) shows a state in which the stopper shaft 24 is inserted into the groove part 17a of the engaged part 17, and the brake body 18 is engaged with the engaged part 17 (a state in which the brake body 18 is disposed in the rotation lock position).

[0070] (2) In the embodiment, the brake lever 28 is supported to be swingable on the axle 14 of the wheel 16, but the brake lever 28 may be configured to be swingably supported on an axis other than the axle 14. Also, in the embodiment, the brake body 18 is restrained in the unlocked position with the brake lever 28 disposed in the horizontal position. In other words, the position where the brake lever 28 is horizontal (horizontal position) is defined as the "first position" of the present invention. However, the "first position" of the present invention may be a position where the brake lever 28 is inclined, and can be changed as appropriate.

[0071] (3) In the embodiment, the guide holes 29b are formed in the left and right side plate portions 281 of the brake lever 28, and the stopper shaft 24 is inserted into the guide holes 29b, thereby connecting the brake body 18 and the brake lever 28 to each other. However, the connecting structure between the brake body 18 and the brake lever 28 is not limited to this. For example, when viewed in the axial direction of the axle 14, the left and right side plate portions 281 may be formed in a roughly U-shape that opens forward, and the stopper shaft 24 may be interposed (held in) inside the U-shape, thereby substantially connecting the brake body 18 and the brake lever 28. That is, the brake lever 28 may be configured to have a notched portion in the side plate portion 281 shown in FIG. 4 such that the guide hole 29b opens forward.

[0072] (4) In the embodiment, the table 1 having the casters 5 on the legs 4 has been described as an application example of the casters 5. However, the object to be moved to which the casters 5 are applied is not limited to a table. The casters 5 according to the present invention can be applied to storage furniture such as a cabinet, a chair, a desk, a cart, and the like as the object to be moved, and the arrangement structure of the switch lever 6 and the wire 7, and the like, can be appropriately changed depending on the object to be moved. [Explanation of symbols]

[0073] 5 Casters (caster device) 6 Switching lever 7 Wire (operating member) 10 Main shaft (connection shaft) 12 Frames 14 axles 16 wheels 17 Engaged part 18 Braking body 19 Brake arm 22 First coil spring (first biasing member) 24 Stopper shaft (engagement part / shaft part) 26 Second coil spring (second biasing member) 28 Brake lever (lever component) 29b Guide hole 292 Expansion section (relief section)

Claims

1. A caster device that is attached to an object to be moved and includes a wheel that rotates around an axle and a braking mechanism that locks the rotation of the wheel, The braking mechanism includes: an engaged portion provided on the wheel and having a plurality of grooves arranged in a circumferential direction around the axle; a braking body having an engaging portion that is inserted into the groove and engages with the engaged portion, the braking body being displaceable between a locking position where the engaging portion engages with the engaged portion to lock the rotation of the wheel and an unlocking position where the rotation of the wheel is permitted; a first biasing member that biases the brake body toward the lock position; a lever member having a connecting portion connected to the brake body and displaceable between a first position at which the brake body is placed in the unlocked position and a second position at which the brake body can be placed in the locked position; a second biasing member that biases the lever member toward the first position with a biasing force greater than the biasing force of the first biasing member; an operating member that applies an operating force to the lever member to displace the lever member from the first position to the second position, A caster device characterized in that the connecting portion is provided with an escape portion that allows the engaging portion to be displaced relative to the lever member when the engaging portion abuts against a partition portion between a pair of adjacent grooves during the process of the lever member being displaced from the first position to the second position.

2. In the caster device according to claim 1, The engagement portion of the brake body has a shaft portion extending parallel to the axle, the lever member is provided to be pivotable about the axle or an axis parallel to the axle, and includes a guide portion that guides the brake body from the unlocked position to the locked position via the axis portion, The connecting portion includes the guide portion, A caster device characterized in that the escape portion is configured to allow the shaft portion to be displaced relative to the connecting portion when the shaft portion abuts against the partition portion.

3. In the caster device according to claim 2, The guide portion is a hole or a notch-shaped portion into which the shaft portion is inserted, A caster device characterized in that the relief portion is a portion formed so as to expand the hole portion or the cutout portion.

4. In the caster device according to any one of claims 1 to 3, A caster body portion is attached to the object to be moved, A caster device, characterized in that the wheel, the braking body, the first biasing member, the lever member, the second biasing member and the operating member are assembled to the caster main body portion.

5. The caster device according to claim 4, A caster device characterized in that it is provided with a connecting shaft that connects the caster main body to the object to be moved so that the caster main body can rotate around a vertical axis.

6. The caster device according to claim 4, The wheels are provided on both sides of the caster body via the axle, A caster device characterized in that the braking body has an engaging portion that can respectively engage with the engaged portion provided on each wheel.

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