Caster and attachment target body

Abstract

To provide a caster provided with a turning regulating mechanism excellent in handling at turning time and straight advancing stability at carrying time.SOLUTION: A caster 10 in which a wheel 30 is turnable with respect to an attachment seat 40, includes a main body 20 fixed to the attachment seat 40 so that an axle 25 supporting the wheel 30 is arranged in an offset manner. The main body 20 is provided with a holding portion 24 protruding toward a side opposite to the axle 25 with respect to a turning shaft 50, and together with the holding portion 24, a columnar locking member 70 held by the holding portion 24, an elastic member 80 provided between the holding portion 24 and a lower end portion of the locking member 70, and a receiving portion 90 including accommodation holes 92A, 92B capable of accommodating a top portion 70T of the locking member 70 constitute the turning regulating mechanism.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a caster, and particularly to a caster provided with a stopper for restricting the turning of a freely rotatable caster (swivel wheel).

Background Art

[0002] In the case of a transport cart or the like, a swivel caster is attached to facilitate direction change. In a swivel caster, a stopper (hereinafter also referred to as a turning restriction mechanism) is provided that can switch between a freely rotatable state and a fixed state in which the turning is restricted and only the wheels rotate.

[0003] For example, by axially rotating an operating lever provided below the mounting seat, a lock plate attached to a freely rotatable yoke engages with a stopper plate. Thereby, the turning of the wheels is restricted (see Patent Document 1).

[0004] Also, a caster provided with a locking mechanism including a locking member that can be moved in the vertical direction and axially rotated, and a coil spring that biases the locking member toward the mounting seat is known (see Patent Document 2). In that case, by moving the operating lever along the guide groove, the locking member rotates axially, and the locking member rises by the elastic force of the coil spring and protrudes from the mounting seat to restrict the turning of the wheels.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] For example, when traveling a relatively long distance with a cart, straight running performance during travel is required. In particular, for a long cart such as a six-wheel cart, straight running stability is required even when passing over road surface irregularities and step portions.

[0007] Therefore, it is required to provide a caster equipped with a turning control mechanism that excels in maneuverability during turning and straight running stability during conveyance.

Means for Solving the Problems

[0008] The present invention is a caster (swivel wheel) that can be turned and can be attached to an object to be attached. For example, it can be configured as a two-wheel caster. The objects to be attached are various, such as conveyance appliances, various devices, and apparatuses to which casters are attached according to their uses, and for example, carts, beds, furniture, product display shelves, etc. are included in the objects to be attached.

[0009] A caster according to one aspect of the present invention includes a main body that supports an axle and is rotatably supported with respect to a mounting seat, a locking member that can move up and down along the vertical direction of the main body and can rotate about an axis, a holding portion that holds the locking member at a position where the main body can turn, and an elastic member that biases the locking member along the vertical direction of the main body. The locking member is configured to be able to move up and down along the vertical direction of the caster, and generally moves up and down along a direction perpendicular to the mounting seat, that is, the vertical direction. The locking member can be configured as, for example, a columnar member.

[0010] Also, in a caster according to one aspect of the present invention, the axle is offset with respect to the turning axis of the main body. That is, the wheel is offset from the turning axis. And the locking member is configured to be able to move up and down on the opposite side of the offset position of the axle with respect to the turning axis, and the holding portion can hold the locking member at a turning control position where the turning of the main body is restricted by a member connecting the locking member to the mounting seat or by contact with the mounting seat.

[0011] The configuration of the holding member is various. For example, the holding member can be integrally formed with the main body. Alternatively, it can also be connected to the main body. The locking member can have various settings for its size and movement range, and accordingly, it is possible to determine the range where the force of the elastic member acts and the direction in which the locking member is biased.

[0012] The elastic member can apply a force to move the locking member downward at a position where the main body can rotate freely, and conversely, can also apply a force to move it upward. For example, an elastic force can be applied downward to a locking member positioned above the lowest position. Here, the "lowest position" indicates the lowest position along the vertical direction where the locking member is held by the holding member. The elastic member can be configured, for example, as a compression coil spring and can apply an elastic force to the holding member and the locking member.

[0013] The locking member can be rotated about its axis after being raised, or the locking member can be raised and rotated about its axis simultaneously. For example, a guide mechanism such as a guide groove can be provided according to the way the position of the locking member moves. Also, an operating portion (such as a knob) for raising and rotating the locking member can be provided at the lower end of the support member.

[0014] Considering the offset arrangement of the axle, it can be configured to selectively hold the locking member at two turning restriction positions along the wheel traveling direction with the turning axis of the main body in between. For example, according to the forward and backward directions of a bogie or the like, the locking member can be configured to abut against the mounting seat or a member that is connected or joined to the mounting seat to restrict turning. For example, when raising and lowering a columnar locking member, it is possible to form a through hole or a recessed hole for accommodating the top of the locking member.

[0015] At least a part or the whole of the elastic member can be configured to be disposed below the turning mechanism of the main body. For example, an elastic member such as a compression coil spring can be disposed between the holding portion and the lower end portion of the locking member, and a configuration can be adopted in which a force is applied to the holding portion and the locking member side at the turning restriction position of the locking member.

[0016] A caster according to another aspect of the present invention includes a main body that supports an axle and is rotatably supported with respect to a mounting seat, a columnar locking member that is vertically movable with respect to the main body and is axially rotatable, and a main body that is integrated or connected to the main body. And a holding portion that holds the locking member by engagement with an engaging portion that has a hole through which the locking member is inserted and protrudes from the side surface of the locking member, one end of which is in contact with the holding portion and the other end of which is near the lower end portion of the locking member. And a compression coil spring that is in contact with a provided support portion, and a receiving portion that is installed between the mounting seat and the holding portion and can accommodate the top of the locking member. The holding portion can hold the locking member in a state where the upper end portion thereof is raised and axially rotated to a turning restriction position where it is accommodated in the receiving portion.

[0017] For example, when the axle is offset with respect to the turning axis of the main body, the receiving portions can be provided in pairs at positions that are rotationally symmetric by 180 degrees with respect to the turning axis of the main body. A knob that is operated to axially rotate the locking member can be formed below the support portion of the locking member. A guide mechanism for guiding the movement path of the engaging portion of the locking member between the lowest position and the turning restriction position of the locking member can be provided for the holding portion.

Effect of the Invention

[0018] According to the present invention, it is possible to provide a caster provided with a turning restriction mechanism having excellent handling during turning and straight-ahead stability during transportation.

Brief Description of the Drawings

[0019]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Mode for Carrying Out the Invention

[0020] Hereinafter, with reference to the drawings, the caster according to the present embodiment will be described.

[0021] FIG. 1 is a perspective view of a caster according to a first embodiment, and FIG. 2 shows a schematic cross-sectional view of the caster. The configuration of the caster will be described with reference to FIGS. 1 and 2.

[0022] The caster 10 can be mounted on a plurality of objects to be attached, and is configured as a double-wheel caster. The object to be attached here is composed of a long cart 100 such as a six-wheel cart, but it can also be composed of ordinary carts, instruments such as beds, etc. For example, in the case of a six-wheel cart, the caster 10 of the present embodiment is mounted at the four corners of the loading platform, and a fixed caster is mounted at the intermediate position.

[0023] The rectangular mounting seat 40 is fixed to the cart 100 by screw fastening or the like using a plurality of holes 40A. In FIGS. 1 and 2, the forward direction and the backward direction when moving the cart 100 are represented by the symbols "F" and "B", respectively. The longitudinal side surface of the mounting seat 40 is along the forward direction and the backward direction.

[0024] The caster 10 includes a main body 20 that is rotatably mounted with respect to the mounting seat 40, an axle 25 supported by the main body 20, and a pair of wheels 30 pivotally supported by the axle 25. The main body 20 is rotatable about a swivel shaft 50 mounted on the mounting seat 40.

[0025] The axle 25 is offset with respect to the swivel shaft 50 that extends downward from the mounting seat 40. When moving the carriage 100, the wheels 30 rotate with the axle 25 in a position opposite to the moving direction (forward direction F or backward direction B) with respect to the main body 20. FIGS. 1 and 2 show the positions of the wheels 30 when the carriage 100 travels in the forward direction. The caster 100 is provided with a locking mechanism (not shown) for locking the rotation of the wheels 30. It is possible to adopt a known locking mechanism for the caster 100, and the description thereof is omitted here.

[0026] A male thread is formed near the top 50T of the swivel shaft 50, and the screw 52 is fastened via the washer 51. A rolling bearing portion 60 is provided on the main body 20, and the swivel shaft 50 is provided with a flange 55 above it. A bearing 57 is fitted near the bottom 50B of the swivel shaft 50, and a retaining ring 58 is interposed between the flange portion formed on the bottom 50B and the main body 20.

[0027] The main body 20 is provided with a portion (hereinafter referred to as a holding portion) 24 that extends horizontally along the side opposite to the axle 25 with respect to the swivel shaft 50. This holding portion 24, a columnar member (hereinafter referred to as a locking member) 70 that can move up and down along the caster vertical direction below the mounting seat 40, and a plate-like member (hereinafter referred to as a receiving portion) 90 formed below the mounting seat 40 constitute a swivel restriction mechanism for restricting the swivel of the main body 20. The swivel restriction mechanism functions as a stopper for locking the swivel of the wheels 30 in accordance with the forward direction F and backward direction B of the carriage 100. Hereinafter, this swivel restriction mechanism will be described in detail.

[0028] A hole 20T through which the columnar locking member 70 is inserted is formed in the holding portion 24. The hole 20T is formed along the vertical direction of the caster, that is, along the swivel shaft 50, and the locking member 70 is arranged through the hole 20T so as to extend along the vertical direction of the caster. Here, the locking member 70 has a circular cross-section, and the shape and size of the hole 20T are determined according to the shape, diameter size, etc. of the locking member 70. An L-shaped guide groove 20G, which will be described later, is formed in the holding portion 24.

[0029] On the side surface of the locking member 70, a rod-shaped portion (hereinafter referred to as the engaging portion) 72 that protrudes in the lateral direction of the caster (substantially horizontal direction) is provided according to the shape and formation position of the guide groove 20G. The engaging portion 72 has a length that protrudes beyond the guide groove 20G and can engage with the peripheral edge portion located at the lowermost position of the guide groove 20G. By the engagement between the engaging portion 72 and the guide groove 20G, the locking member 70 is held and positioned. At the lower end portion of the locking member 70, a knob 75 is formed, which is operated to raise, lower, and axially rotate the locking member 70.

[0030] An elastic member 80 is provided below the holding portion 24. Here, the elastic member 80 is configured as a compression coil spring. One end of the elastic member 80 on the mounting seat 40 side (upper side) is in contact with the outer surface of the holding portion 24, and the other end is in contact with and supported by a flange 73 (support portion) provided on the lower end portion side of the locking member 70. In a state where the locking member 70 is held by the holding portion 24, that is, in an engaged state between the engaging portion 72 and the guide groove 20G, the elastic member 80 is in a non-compressed state.

[0031] The receiving portion 90 is integrally attached to the lower side of the mounting seat 40. Also, a pair of concave receiving holes 92A and 92B are provided in the receiving portion 90. The pair of receiving holes 92A and 92B are formed at positions that are rotationally symmetric by 180 degrees with respect to the center C of the turning shaft 50 and are formed along the traveling direction of the carriage 100 when the turning of the wheel 30 is restricted. The sizes and depths of the pair of receiving holes 92A and 92B are determined according to the diameter of the locking member 70 and the moving range along the vertical direction.

[0032] FIG. 3 is a side view of the caster 10 when the main body 20 (wheel 30) is in a freely rotatable position. As shown in FIG. 3, in a state where the locking member 70 is held at the lowest position (hereinafter referred to as the lowermost position) by the holding portion 24, the top 70T of the locking member 70 is located below the receiving portion 90. Therefore, the main body 20 can rotate around the turning shaft 50, and the traveling direction of the wheel 30 can also be freely changed.

[0033] Figure 4 is a side view of the caster 10 when the main body 20 (wheel 30) is in the turning restriction position. The guide groove 20G formed in the holding portion 24 is formed in an L shape so that the rod-shaped engaging portion 72 can be guided along the vertical and horizontal directions of the caster. When the top 70T of the locking member 70 and the receiving hole 92A of the receiving portion 90 are in the opposing position, the operator can raise the locking member 70 from the lowermost position to the corner portion of the guide groove 20G. The top 70T of the locking member 70 abuts against the bottom 93A of the receiving hole 92A of the receiving portion 90 or rises to a position in the vicinity thereof.

[0034] After raising the locking member 70 to the corner portion of the guide groove 20G, when the knob 75 of the locking member 70 is turned in a predetermined direction, the engaging portion 72 moves along the horizontal direction of the guide groove 20G, and the locking member 70 is rotated about its axis. The operator turns the knob 75 until the engaging portion 72 reaches the horizontal end portion 20C of the guide groove 24.

[0035] During the raising and axial rotation of the locking member 70, the elastic member 80 is compressed and an elastic force acts on the upper and lower sides of the caster, that is, toward the holding portion 24 and the knob 75. The horizontal end portion 20C of the guide groove 20G is recessed downward on the caster side so as to accommodate the rod-shaped engaging portion 72. By the engaging portion 72 being locked at the horizontal end portion 20C of the guide groove 20G, the locking member 70 is positioned by the holding portion 24.

[0036] Since the top 70T of the locking member 70 is accommodated in the receiving hole 92A of the receiving portion 90, when the main body 20 attempts to turn, the top 70T of the locking member 70 and its vicinity abut against the peripheral edge of the receiving hole 92A of the receiving portion 90, and the turning of the main body 20 is restricted. Further, since the engaging portion 72 of the locking member 70 drops into the concave horizontal end portion 20C and is locked in the guide groove 24, the axial rotation of the locking member 70 is restricted.

[0037] The receiving hole 92B located at a position rotationally symmetric by 180 degrees with respect to the receiving hole 92A has the same size as the receiving hole 92A and is sized to accommodate the top 70T of the locking member 70. When the carriage 100 is retracted, when the wheel 30 is turned to a position exactly opposite to those in FIGS. 1 to 4 and the top 70T of the locking member 70 faces the receiving hole 92B, by operating the knob 75, the locking member 70 can be lifted and rotationally displaced about its axis, and the rotation of the main body 20 and the rotational displacement of the locking member 70 about its axis can be restricted.

[0038] When an operator moves the carriage 100 with a load thereon to a predetermined location, after turning the carriage 100 in the traveling direction, by operating the knob 75 of the locking member 70, the operator switches from a position where the main body 20 can rotate (rotatable position) to a position where the rotation of the main body 20 is restricted (rotation-restricted position). The wheels 30 rotate in a rotation-restricted state, and the carriage 100 travels straight.

[0039] When the carriage 100 reaches a predetermined location or its vicinity, the operator switches the main body 20 from the rotatable position to the rotation-restricted position. Then, while adjusting the orientation of the carriage 100, the operator stops the carriage 100 at the predetermined location.

[0040] Similarly, when the carriage 100 is retracted, it is possible to switch the main body 20 between the rotatable position and the rotation-restricted position. After turning the position of the wheel 30 to a position where the locking member 70 opposes the receiving hole 92B of the receiving portion 90, by raising the locking member 70 to bring the top 70T of the locking member 70 into contact with or move it close to the bottom 93B of the receiving hole 92B and rotationally displacing the locking member 70 about its axis, the main body 20 can be set to the rotation-restricted position.

[0041] According to this embodiment, the caster 10 in which the wheel 30 is rotatable with respect to the mounting seat 40 includes a main body 20 fixed to the mounting seat 40 so as to offset the axle 25 that supports the wheel 30. And, a holding portion 24 that protrudes toward the side opposite to the axle 25 with respect to the pivot axis 50 is provided on the main body 20. Together with the holding portion 24, a columnar locking member 70 held by the holding portion 24, an elastic member 80 provided between the holding portion 24 and the lower end portion of the locking member 70, and a receiving portion 90 having receiving holes 92A and 92B capable of accommodating the top portion 70T of the locking member 70 constitute a turning restriction mechanism.

[0042] By operating the knob 75 by the operator, it is possible to easily raise and rotate the shaft of the locking member 70. The engaging portion 72 of the locking member 70 moves along the guide groove 20G according to the operator's operation, so that the caster can be freely switched between the freely rotatable position and the turning restricted position of the main body 20.

[0043] When the cart 100 is a long cart, straight running performance is required. When the cart 100 is traveling and exceeds unevenness or a step on the road surface, a pushing force against the offset wheel 30 and a load from the mounting seat 40 side may act. Even when such a force acts, the contact between the locking member 70 and the receiving portion 90 restricts the turning of the main body 20 (wheel 30), and the straight running of the cart 100 can be stably maintained.

[0044] In accordance with the offset arrangement of the axle 25, the turning restriction mechanism is provided on the side opposite to the pivot axis 50. Since it is not configured to be provided above or beside the wheel 30, it does not become an obstacle during the rotation of the wheel 30. Also, the sizes and structures of the components of the turning restriction mechanism, the length of the locking member 70, the moving range along the vertical direction of the caster, the elastic performance of the elastic member 80, etc. can be appropriately adjusted and selected.

[0045] In addition, since the holding portion 24 is integrally formed with the main body 20, the position along the advancing direction of the locking member 70 is surely determined. In the vertical direction, positioning is performed at a low position by the biasing force of the elastic member 80. Therefore, under the condition that the carriage 100 travels over steps and unevenness, the force of the elastic member can directly act on the main body, and the main body 20 is stabilized against the swinging and fluctuation of the wheels 30.

[0046] At the turning restriction position, an elastic force acts to prevent the locking member 70 from changing its position due to the compression of the elastic member 80. Therefore, even when the carriage 100 exceeds a road surface step, the position change of the locking member 70 along the caster vertical direction is suppressed, and the unintentional switching to the freely rotatable position is prevented.

[0047] The elastic member 80 is located below the rolling bearing portion 60 which is a turning mechanism, and its position along the caster vertical direction does not differ significantly from that of the axle 25. Therefore, even when the carriage 100 is moved at a relatively high speed, regardless of the offset arrangement of the axle 25, the main body 20 with the holding portion 24 and the wheels 30 arranged on both sides of the turning axis 50 integrally changes its position, does not pitch even on steps, and can maintain stable straight running in combination with the low center of gravity of the caster 10.

[0048] Furthermore, below the mounting seat 40 of the caster 10, a receiving portion 90 is provided which forms a pair of receiving holes 92A, 92B that come into contact with the top 70T of the locking member 70 and its vicinity. By providing the pair of receiving holes 92A, 92B, the main body 40 can be switched to the turning restriction position regardless of whether the carriage 100 moves forward or backward. Also, the configuration of the receiving portion 90 can be determined according to the length of the locking member 70, the position and diameter size of the top 70T of the locking member 70 at the turning restriction position, etc. Therefore, it is not necessary to specifically match the configuration of the mounting seat 40 itself to the configuration of the locking member 70, and it can be surely fixed to various types of carriages 100.

[0049] The receiving hole of the receiving part may be configured to be provided one in the forward direction. It is also possible to replace it with an elastic member other than the compression coil spring, and it is also possible to configure it with a locking member other than a columnar shape. Furthermore, a configuration may be adopted in which the locking member is brought into contact with and positioned with respect to the mounting seat without providing a receiving part.

[0050] Next, with reference to FIGS. 5 and 6, a caster according to the second embodiment will be described. In the second embodiment, by operating the locking member, the locking member moves upward to the turning restriction position due to the biasing force of the elastic member in the compressed state.

[0051] FIGS. 5 and 6 are side views of the caster according to the second embodiment, showing side views in the freely rotatable position and the turning restriction position, respectively.

[0052] The caster 10' includes a main body 20' that is rotatably attached to the mounting seat 40'. On the main body 20', a holding portion 24' is provided on the side opposite to the axles arranged offset. A columnar locking member 70' is inserted through the holding portion 24', and an elastic member 80' that is a compression coil spring is installed with respect to the locking member 70'. Note that in FIGS. 5 and 6, the axles and wheels are not shown.

[0053] Both ends of the elastic member 80' are in contact with the flange provided on the locking member 70' and the holding portion. When the engaging portion 72' is located at the bottom end of the L-shaped guide groove 20'G provided in the holding portion 24', the elastic member 80' is in a compressed state (see FIG. 5). The elastic member 80' applies a force (biases) to move the locking member 70' upward, but due to the engagement between the engaging portion 72' and the guide groove 20'G, the locking member 70' does not move upward, and the main body 20' is rotatable and in a state where the wheels can rotate freely (see FIG. 5).

[0054] When the operator rotates the knob 75' about its axis and moves the engaging portion 72' to the L-shaped corner portion of the guide groove 20'G, the locking member 70' rises due to the biasing force of the elastic member 80', and the engaging portion 72' abuts against the upper end portion of the guide groove 20G'. As a result, the top 70'T of the locking member 70' is received in the receiving hole 92'A and is set at the rotation restricting position (see Fig. 6). When the carriage is moved backward, the top 70'T of the locking member 70' is received in the receiving hole 92'B.

[0055] Thus, according to the second embodiment, by rotating the knob 75' about its axis, it is possible to switch from the freely rotatable position of the main body 20 (wheel) to the rotation restricting position, and the operability of switching by the operator becomes easy. On the other hand, similar to the first embodiment, the locking member 70' is arranged on the side opposite to the offset wheels, the locking member 70' has a length (size) facing each other over the entire vertical direction of the main body 20', and by arranging its top 70'T at a position exceeding the rolling bearing portion, a long carriage can be stably run.

Explanation of Reference Numerals

[0056] 10 Caster 20 Main Body 20G Guide Groove (Guide Mechanism) 24 Holding Portion 25 Axle 30 Wheel 40 Mounting Seat 50 Swivel Axis 70 Locking Member 70T Top 72 Engaging Portion 73 Flange (Support Portion) 75 Knob 80 Elastic Member 90 Receiving Portion 92A, 92B Receiving Hole 100 Carriage

Claims

1. A main body that supports an axle and is rotatably supported with respect to a mounting seat, a locking member that is movable up and down along the vertical direction of the main body and is rotatable about an axis, a holding portion that holds the locking member at a rotatable position of the main body, and an elastic member that biases the locking member along the vertical direction of the main body, wherein the axle is offset with respect to the rotation axis of the main body, the locking member is movable up and down on the opposite side of the offset position of the axle with respect to the rotation axis, and the holding portion is capable of holding the locking member at a rotation restricting position where the rotation of the main body is restricted by contact with a member connecting the locking member to the mounting seat or contact with the mounting seat. A caster characterized by this.

2. The caster according to claim 1, wherein the holding portion is integrally formed with the main body.

3. The caster according to claim 1, wherein the holding portion is capable of holding the locking member at two rotation restricting positions along the wheel traveling direction with the rotation axis of the main body interposed therebetween.

4. The elastic member applies an elastic force downward to the locking member located at a position above the lowest position, and the holding portion is capable of holding the locking member in a state where it has moved from the lowest position to the rotation restricting position by ascending and rotating about an axis. A caster characterized by this.

5. A main body that supports an axle and is rotatably supported with respect to a mounting seat, a columnar locking member that is movable up and down with respect to the main body and is rotatable about an axis, a holding portion that is integrally formed with or connected to the main body, has a hole through which the locking member is inserted, and holds the locking member by engagement with an engaging portion protruding from the side surface of the locking member, a compression coil spring having one end in contact with the holding portion and the other end in contact with a support portion provided around the vicinity of the lower end of the locking member, and a receiving portion that is installed between the mounting seat and the holding portion and is capable of accommodating the top of the locking member, and the holding portion is capable of holding the locking member in a state where it has been raised and rotated about an axis to a rotation restricting position where its upper end is accommodated in the receiving portion. A caster characterized by this.

6. The axle is offset with respect to the rotation axis of the main body, and the receiving portions are provided in pairs at positions that are rotationally symmetric by 180 degrees with respect to the rotation axis of the main body. The caster according to claim 5, characterized by this.

7. The caster according to claim 5, characterized in that a knob operated to axially rotate the locking member is formed below the support portion of the locking member.

8. The caster according to claim 5, characterized in that the holding portion is provided with a guide mechanism for guiding a movement path of the engaging portion of the locking member between the lowermost position and the turning restriction position of the locking member.

9. An attached body, characterized in that a plurality of the casters according to any one of claims 1 to 8 are mounted.

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