JP2001150902A - Caster with automatic lock mechanism, and hand cart provided therewith - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce rotation resistance of a ground wheel of a sensor wheel while restraining costs or weight of a caster with automatic lock mechanism. SOLUTION: This caster comprises a bracket 63, a wheel 66, and a center wheel 20. The wheel 66 is axially supported by the bracket 63. The center wheel 20 rolls together with the wheel 66 on a road surface, and fits in a vertical groove C on a transport surface B such as an escalator. The center wheel 20 comprises a slider 34, a lock pin 40, an annular ground wheel 20a, and a plurality of ball bearings 33. The slider 34 is supported by the bracket so as to be vertically movable. The lock pin 40 is fixed to the slider 34, and locked with respect to the wheel 66 in a rotating direction when the sensor wheel 20 fits in the vertical groove C. The ground wheel 20a is arranged outside the slider 34. The plural ball bearings 33 are arranged between the slider 34 and the ground wheel 20a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a caster with an automatic locking mechanism and a hand cart provided with the same, and more particularly to a hand cart provided with a sensor wheel for restricting rotation of a wheel by falling into a groove on a transport surface of a transport device.

[0002]

2. Description of the Related Art Transport devices, such as escalators and moving walkways, are devices that continuously transport people. When carrying a hand cart carried by a person together with such a transport device, it is desirable that the movement of the casters of the hand cart be locked so that the hand cart can be transported safely.

In order to automatically perform the locking operation of the caster, a sensor wheel is provided which can be inserted into a vertical groove (a vertical groove engraved on the transport surface along the transport direction) of the transport device. A caster with an automatic locking mechanism is disclosed in Japanese Patent Publication No. 51-27331. In this caster, the rolling of the wheel and the turning of the wheel receiver are restricted in accordance with the depression of the sensor wheel into the vertical groove.

[0004]

In the caster disclosed in the above publication, the inner peripheral portion of the tracing wheel (grounding wheel) 3 is sandwiched between the ball bearing disks 4 and 5 from both sides, so that the grounding wheel 3 is provided on both sides. It is rotatably supported by ball bearing disks 4,5. Here, the grounding wheel 3 always rotates when the cart moves, and it is desirable that the rotation be smooth. However, in the structure of the above-mentioned publication in which the inner peripheral portion of the grounding wheel 3 is sandwiched between the ball bearing disks 4 and 5 via the balls from both sides, the rolling resistance is large and an extra load is imposed on a person pushing the hand cart.

On the other hand, in the hand cart disclosed in JP-A-11-310136, the rotation of the grounding wheel is smoother. Here, the outer-ground contact wheel is rotatably supported by the inner-side slider 34 by the annular large-diameter ball bearing 33. In this way, if a commercially available large-diameter ball bearing is used,
The rotation resistance of the grounding wheel can be reduced.

[0006] However, large-diameter ball bearings are expensive, and there is a problem that the production cost of casters increases.
In addition, since a large-diameter ball bearing is heavy, a structure using a large-diameter ball bearing also has a higher weight than a structure in which a grounding wheel is sandwiched between two ball bearing disks. An object of the present invention is to reduce the rotational resistance of a ground wheel of a sensor wheel while suppressing the cost and weight of a caster in a caster with an automatic locking mechanism and a hand cart provided with the caster.

[0007]

According to a first aspect of the present invention, there is provided a caster having an automatic locking mechanism including a caster body, wheels, and a sensor wheel. The wheels are supported by the caster body. The sensor wheel rolls together with the wheel on the road surface, falls into a groove provided on the transport surface on the transport surface of the transport device, and regulates the rotation of the wheel. The sensor wheel includes a slider, a lock member, an annular ground wheel, and a plurality of bearings. The slider is supported by the caster body so as to be vertically movable. The lock member is connected to the slider, and locks in a rotational direction with respect to a part of the wheel when the sensor wheel falls into the groove. The grounding wheel is located outside the slider. A plurality of bearings are arranged between the slider and the ground wheel.

In this caster, when a wheel pivotally supported by the caster body rotates on the road surface, the grounding wheel rotatably supported by a slider supported by the caster body via a plurality of bearings is also mounted on the road surface. Rotate while touching. And when the caster comes on the transport side of the transport device,
The sensor wheel falls into a vertical groove on the transport surface, and a lock member connected to the slider locks a part of the wheel in a rotational direction. Then, the wheels cannot rotate with respect to the caster body supporting the slider, and the wheels are locked.

Here, a structure is employed in which the slider rotatably supports the grounding wheel by a plurality of bearings disposed between the grounding wheel and the slider. In other words, the grounding wheel is rotatably supported by a plurality of bearings, rather than by a single annular and large-diameter bearing as in the related art. Therefore, the size of each bearing can be reduced, and the cost of the bearing can be reduced as compared with the related art, even if the number of bearings is increased. In addition, as compared with the structure in which the grounding wheel is sandwiched between the ball bearing disks from both sides, the structure of the present invention in which a plurality of small bearings are provided to support the grounding wheel has a smaller rotation resistance of the grounding wheel.

The caster according to claim 2 is the caster according to claim 1, wherein the plurality of bearings are arranged at equal intervals in the circumferential direction. Here, the slider is supported by the slider by a plurality of bearings arranged at equal intervals in the circumferential direction. As a result, there is no variation in the circumferential direction of the force with which the bearing supports the grounding wheel,
The deformation and fatigue of the grounding wheel can be suppressed.

The caster according to claim 3 is the caster according to claim 1 or 2, wherein the bearing is a rolling bearing in which a rolling element is held between an inner ring and an outer ring. Then, the inner ring of the bearing is fixed to the slider, and the outer ring of the bearing supports the inner peripheral portion of the ground wheel. Here, the inner peripheral portion of the grounding wheel is supported by the outer ring of each of the plurality of bearings. Then, the inner ring of each bearing is fixed to the slider.

A caster according to a fourth aspect is the caster according to any one of the first to third aspects, wherein the lock member is disposed between two of the plurality of bearings in the circumferential direction. Here, the locking member is disposed between the bearing and the bearing in the circumferential direction by utilizing the fact that the slider supports the ground wheel with a plurality of bearings instead of one annular bearing. As a result, the lock member can be connected to the outer portion of the slider than before, and the force received by the lock member from the wheel when locked to a part of the wheel becomes smaller than before. That is, conventionally, an annular bearing for supporting the grounding wheel was present on the outer peripheral portion of the slider, so that the lock member could not be arranged there, but in the present invention, the grounding wheel is supported by a plurality of bearings. With such a structure, it is possible to arrange a lock member between the bearings, and as a result, it is possible to reduce the force acting between the lock member and the wheel at the time of locking.

A caster according to a fifth aspect is the caster according to any one of the first to fourth aspects, wherein the lock member is supported on the caster body so as to be vertically movable and non-rotatably, and a sensor wheel is provided. When the vehicle falls into a groove on the transport surface, a part of the wheel and the caster body are connected in the rotational direction. Here, a lock member connected to the slider is supported by the caster body. Since the lock member is supported by the caster body via the slider, the wheel can be locked by locking to a part of the wheel even if it is not directly supported by the caster body, but is directly supported by the caster body. By doing so, the wheels can be locked without the intervention of the slider. That is, when the sensor wheel falls into the groove, the lock member also moves downward and locks on a part of the wheel. At this time, a part of the wheel and the caster body are connected in the rotational direction via the lock member, The wheel is in a state of being locked to the caster main body in the rotational direction via only the lock member without passing through the slider.

As described above, no extra force acts on the slider when the wheel is locked, and the deformation and breakage of the slider can be suppressed. A caster according to a sixth aspect is the caster according to any one of the first to fifth aspects, further comprising a spring. The spring is disposed between the caster body and the slider, and urges the slider downward with respect to the caster body.

Here, since the slider is biased downward by the biasing force of the spring with respect to the caster body,
The falling of the sensor wheel into the groove when it is placed on the transport surface is more reliable. The caster according to claim 7,
The caster according to claim 6, wherein the spring is disposed between two of the plurality of bearings in a circumferential direction.

Here, the spring is disposed so as to extend between the bearings in the circumferential direction by utilizing the fact that the ground wheel is supported by the slider by a plurality of bearings instead of one annular bearing. I have. As a result, the length of the spring can be set longer than before, and the degree of freedom in designing the setting of the biasing force by the spring and the like is increased.

The caster according to claim 8 is the caster according to any one of claims 1 to 7, wherein the wheels are provided on both sides of the sensor wheel. When the sensor wheel falls into a groove on the transport surface, the lock member locks a part of both wheels in a rotational direction. The caster according to claim 9 is the caster according to any one of claims 1 to 8, wherein the wheel has a concave portion into which the lock member can enter.

[0018] A hand cart according to a tenth aspect includes a cart main body and a caster. The caster is the caster according to any one of claims 1 to 9, and is mounted on a lower portion of the cart body.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS <Hand Cart> FIG. 1 shows a hand cart using a caster according to an embodiment of the present invention.
Shown in This hand cart is used by a traveler at an airport, and is a cart pushed by hand while carrying luggage such as a trunk. As shown in FIG. 1, the hand cart mainly includes a cart body 1, a front wheel caster 2, and left and right rear wheel casters 3.

The cart body 1 is formed by bending a plurality of types of pipes. This cart body 1
Vertical pipe 11, carrier pipe 12, guard pipe 1
3-16. The vertical pipe 11 is located above both rear wheel casters 3 and extends in the vertical direction. The bed pipe 12 extends forward from a lower part of the vertical pipe 11, and supports a lower surface of a load such as a trunk. The portion of the loading pipe 12 supporting the load is inclined forward.
The guard pipes 13 to 16 are fixed to the vertical pipe 11 or the bed pipe 12 and stand upright so as to tilt obliquely rearward. These guard pipes 13 to 16 serve to delimit the loading space of the load and to guard the front and rear surfaces of the load. Further, both ends of the handle 4 are fixed to the upper rear surface of the vertical pipes 11. Handle 4
Is a U-shaped pipe member.

The front wheel caster 2 is a two-wheel type caster, and is fixed to the center of the front of the cart body 1 in the width direction. The front wheel caster 2 is a caster with an automatic locking mechanism according to the present invention, and the front wheel caster 2 will be described later in detail. The rear wheel casters 3 are single-wheel type casters, and are provided at the left and right ends of the rear lower end of the cart body 1, respectively. Specifically, the rear wheel caster 3 includes a wheel 3a and a bracket 3b that supports the wheel 3a, and an upper portion of the bracket 3b is fixed to a lower surface of the vertical pipe 11 of the cart body 1.

The hand cart is a rear wheel caster 3
As a mechanism for braking and releasing the rotation of the wheel 3a,
It has a brake mechanism. The brake mechanism includes a brake lever 51, a brake shoe, a brake rod, a brake spring, and the like. Here, the brake is applied to the wheel 3a of the rear wheel caster 3 unless the brake lever 51 is gripped with the handle 4. However, when the brake lever 51 is depressed and gripped with the handle 4, the brake of the wheel 3a of the rear wheel caster 3 is braked. Comes off and can be pushed by hand.

<Front Wheel Casters> The front wheel casters 2 are shown in FIG.
4 is a twin-wheel type caster having a structure shown in FIG. The front wheel caster 2 mainly includes a mounting base 18, outer and inner brackets 63 and 64, and a thrust bearing 19.
, Two wheels 66 and 67 and the sensor wheel 20
It is composed of

(Mounting pedestal) The mounting pedestal 18 is a substantially square plate-like member provided with mounting holes at four corners as shown in FIG. (Bracket) Both outer and inner brackets 6
Reference numerals 3 and 64 denote members for supporting the wheels 66 and 67 via the shaft 65 and supporting the sensor wheel 20 so that the sensor wheel 20 can move up and down by a predetermined amount. Each of the brackets 63 and 64 has a substantially U-shaped cross section as a wheel receiver for supporting the shaft 65. The shaft 65 extends horizontally and connects both ends of both brackets 63 and 64.

(Thrust bearing) Thrust bearing 19
Is disposed between the mounting base 18 and the wheels 66, 67,
It is a mechanism that enables relative rotation of both about a vertical axis,
It is composed of a plurality of members. This thrust bearing 1
9 enables the wheels 66 and 67 to turn with respect to the cart body 1.

In the thrust bearing portion 19, as shown in FIG. 3, between the upper and lower races 26, 27 and the intermediate race 28, two types of large and small steel balls 29, 30 are provided with their race radii shifted from each other. Is provided. The upper race 26 is fixed to the mounting base 18. The intermediate race 28 is fixed to the upper plate 63a of the outer bracket 63. The lower race 27 is fixed to the mounting base 18 in the same manner as the upper race 26. A notch 31 is formed on the front side (the right side in FIG. 3) of the outer peripheral portion of the lower race 27.

(Wheels) The wheels 66, 67 are a pair of left and right wheels, and are rotatable about a shaft 65 fixed to brackets 63, 64. These wheels 66 and 67 have the same structure which is symmetrical to the left and right, and a disk 22 supported on the shaft 65 via the bearing 21 is provided.
And a rubber tire 23 mounted on an outer peripheral rim of the disk 22. The disk 22 is formed by stacking two press-formed products of a steel plate. Disc 2
2, a plurality of concave portions 24 shown in FIG. 2 are formed at equal intervals in the circumferential direction.

(Sensor wheel) Left and right wheels 66, 67
Between them, a sensor wheel 20 for detecting a vertical groove provided on a transport surface of a transport device such as an escalator is provided. The sensor wheel 20 mainly includes an annular grounding wheel 20a, a disk-shaped slider 34 disposed on the inner peripheral side of the grounding wheel 20a, and a grounding wheel 2a.
0a and four ball bearings 33 arranged between the slider 34. FIG. 5 shows an acute transverse cross-sectional view of the sensor wheel 20, and FIG.

The grounding wheel 20a is formed by injection molding of a synthetic resin material such as nylon, and has substantially the same outer diameter as the wheels 66 and 67. Slider 3
Numeral 4 is formed by injection molding of a synthetic resin material such as nylon, and a shaft insertion hole 36 that is long in the vertical direction with respect to the diameter of the shaft 65 is formed at the center thereof. Thus, the slider 34 can be displaced up and down with respect to the shaft 65. A recess 37 extending downward in the radial direction is formed in the lower inner peripheral surface of the shaft insertion hole 36. A compression spring 39 is contracted between the bottom surface of the recess 37 and the outer peripheral surface of the pipe 38 provided on the shaft 65. This spring 39
Urges the slider 34 downward (see FIGS. 2, 5 and 6).

A hole 34a (see FIG. 6) is provided in the upper part of the slider 34, and a lock pin (lock member) 40 is provided in parallel with the axis of the shaft 65 as shown in FIG. The lock pin 40 has a slider 3
A pair of left and right clips 41 for restricting the movement in the axial direction with respect to 4 is provided. The left and right ends of the lock pin 40 are provided on the left and right side plates 64b of the inner bracket 64, respectively.
64c pass through the guide holes 42 provided in each of them and escape to the outside thereof. The guide hole 42 is provided for the slider 3
In addition to restricting the rotation of the slider 4, the slider 4 is formed vertically long so as not to restrict the vertical movement of the slider 34 (see FIG. 7).

The four ball bearings 33 are connected to the ground wheel 20a.
And the slider 34 are arranged at equal intervals in the circumferential direction (see FIG. 6). These ball bearings 33
Each is a rolling bearing in which a plurality of balls are held between an inner ring 33a and an outer ring 33b. And the inner ring 33a
Is fixed to a slider 34 as shown in FIG. The outer ring 33b supports the inner peripheral surface of the ground wheel 20a. The grounding wheel 20a is prevented from coming off the ball bearing 33 by the outer peripheral portion of the slider 34 sandwiching the radial center portion of the grounding wheel 20a from both sides.

Further, as shown in FIG.
The hole 34a of the slider 34 through which the spring 3 is disposed is arranged between the upper two ball bearings 33 in the circumferential direction.
The recess 37 of the slider 34 for accommodating the
Between the two ball bearings 33 in the circumferential direction. (Other members) Above the sensor wheel 20, there is provided a lever 47 which can swing vertically about a pivot pin 46 provided between left and right side plates 64b and 64c of the inner bracket 64. I have. The lever 47 has a U-shaped cross section, and a protruding piece 48 bent upward is formed at the front end (the right end in FIG. 3). On the other hand, upper ends of a pair of left and right link members 49 are pivotally attached to the rear end of the lever 47 (the left end in FIG. 3). These link members 49 are members for transmitting the vertical movement of the slider 34 to the lever 47, and the lower ends thereof are pivotally connected to lock pins 40 provided through the slider 34 (FIGS. 2 and 3). reference).

<Motion of Front Wheel Caster When Hand Cart Moves> When the hand cart travels on a smooth road surface, the sensor wheel 20 urged downward by the spring 39 as shown in FIGS. In a state of being constantly pressed against the road surface A, the vehicle rolls on the road surface A together with the left and right wheels 66 and 67. On the other hand, when the hand cart is put on a transport device such as an escalator, the sensor wheel 20 of the front wheel caster 2 is inserted into the vertical groove C formed on the transport surface B as shown in FIG.
Is depressed. Then, the slider 34 moves downward, and the left and right ends of the lock pin 40 are moved to the left and right wheels 6.
6 and 67 are respectively fitted into the concave portions 24, and the rolling of the left and right wheels 66 and 67 is locked. At this time,
Left and right side plates 64 of the inner bracket 64 having high rigidity
Since the displacement of the lock pin 40 in the front-rear direction is restricted by the b and 64c, a large reaction force can be obtained with respect to an external force for rotating the wheels 66 and 67, and the rolling of the wheels 66 and 67 can be ensured. Can be restrained.

The slider 34 and the lock pin 40
In response to the downward movement, the link member 49 is displaced downward, and the lever 47 swings accordingly (see FIG. 7).
Then, the projecting piece 48 provided at the front end of the lever 47 fits into the notch 31 of the bearing ring 27 below the thrust bearing 19. As a result, the brackets 63 and 64 cannot rotate relative to the mounting base 18, and the brackets 63 and 64
The turning of 64 is locked.

When the front wheel casters 2 return to the flat road surface from the transport surface of the transport device, the sensor wheel 20 is pushed up against the urging force of the spring 39, and the slider 34 and the lock pin 40 are raised accordingly. do it,
The left and right ends of the lock pin 40 come out of the concave portions 24 of the disk 22, and the locked state of the rolling of the wheels 66 and 67 is released. At the same time, the projecting piece 48 of the lever 47 comes out of the notch 31 and the locked state of the turning of the brackets 63 and 64 is also released.

As described above, in the hand cart according to the present embodiment, the locked state and the unlocked state of both the rolling and turning operations of the front wheel caster 2 are changed in accordance with the change of the road surface condition as the vehicle gets in and out of the transport device. The locked state is automatically switched. For this reason, at the starting point of a transport device such as an escalator, for example, the locked front wheel casters 2 are pulled by the transport device, and the hand cart is moved into the transport device in a retracted manner. Also, at the end point of the transport device, when the front wheel caster 2 comes out of the transport surface and is unlocked, the hand cart can be pushed out.

<Features of Front Wheel Caster of the Present Embodiment> (1) In the front wheel caster 2, the slider 34 can rotate the ground wheel 20 a by a plurality of ball bearings 33 arranged between the ground wheel 20 a and the slider 34. The structure to support is adopted. That is, the grounding wheel 20a is rotatably supported by a plurality of ball bearings 33, instead of a single annular large-diameter bearing as in the related art.

For this reason, the size of each ball bearing 33 is reduced, and the cost can be reduced as compared with the related art even if the number is increased to four. Further, the rotation resistance of the grounding wheel 20a is smaller than that of the conventional structure in which the grounding wheel 20a is sandwiched between the ball bearing discs from both sides. (2) In the front wheel caster 2, the ball bearing 33 is arranged in the circumferential direction. Since the ball bearings 33 are arranged at intervals, the force in which the ball bearings 33 support the grounding wheel 20a does not vary in the circumferential direction, and the supporting state of the grounding wheel 20a is stable. For this reason, the deformation of the unbalance is avoided, the traveling is stabilized, and the life of the grounding wheel 20a is prolonged.

(3) In the front wheel caster 2, the hole 34a of the slider 34 through which the lock pin 40 passes
The two ball bearings 33 are arranged between the circumferential directions. That is, the lock pin 40 is disposed between the upper two ball bearings 33 in the circumferential direction. In the conventional structure in which the grounding wheel 20a is supported by the annular bearing, the lock pin has to be arranged on the inner peripheral side of the bearing. However, here, a plurality of lock pins are arranged at intervals in the circumferential direction. The lock pin 40 is arranged between the upper two ball bearings 33 in the circumferential direction by utilizing the structure in which the grounding wheel 20 a is supported by the ball bearings 33.

For this reason, the lock pin 40 is located at a portion outside the conventional structure.
When the lock pin 40 is locked in the concave portion 24 of the wheels 66 and 67, the reaction force received by the lock pin 40 from the wheels 66 and 67 is small. Accordingly, the weight of the lock pin 40 and the disk 22 of the wheels 66 and 67 can be reduced. (4) In the front wheel caster 2, the depression 37 of the slider 34 for accommodating the spring 39 is disposed so as to extend between the lower two ball bearings 33 in the circumferential direction. That is, the spring 39 is disposed so as to extend between the lower two ball bearings 33 in the circumferential direction.

In the conventional structure in which the grounding wheel 20a is supported by the annular bearing, the spring has to be arranged on the inner peripheral side of the bearing, but here, it is arranged at intervals in the circumferential direction. The spring 39 is disposed so as to extend between the lower two ball bearings 33 in the circumferential direction by utilizing the structure in which the grounding wheel 20 a is supported by the plurality of ball bearings 33.

For this reason, the entire length of the spring 39 is longer than in the prior art, and an appropriate urging force can be easily set.

[0043]

According to the present invention, since a structure is employed in which the slider rotatably supports the grounding wheel by a plurality of bearings disposed between the grounding wheel and the slider, the conventional structure using one annular bearing is adopted. As a result, the size of each bearing can be reduced, and the cost of the bearing can be reduced as compared with the related art even if the number of bearings is increased. In addition, as compared with the structure in which the grounding wheel is sandwiched between the ball bearing disks from both sides, the structure of the present invention in which a plurality of small bearings are provided to support the grounding wheel has a smaller rotation resistance of the grounding wheel.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view of a hand cart according to an embodiment of the present invention.

FIG. 2 is a front partial cross-sectional view of a front wheel caster.

FIG. 3 is a partial side sectional view of a front wheel caster.

FIG. 4 is a top view of a front wheel caster.

FIG. 5 is an acute angle cross-sectional view of the sensor wheel.

FIG. 6 is a longitudinal sectional view of one side of a sensor wheel.

FIG. 7 is a side view of a front wheel caster in which a sensor wheel falls into a vertical groove on a transport surface.

[Explanation of symbols]

 Reference Signs List 1 cart main body 2 front wheel caster (caster with automatic lock mechanism) 20 sensor wheel 20a grounding wheel 24 concave portion 33 ball bearing (bearing) 33a inner ring 33b outer ring 39 spring 34 slider 40 lock pin (lock member) 38 pipe (caster body) 63 outer Bracket (caster body) 64 Inner bracket (caster body) 65 Shaft (caster body) 66, 67 Wheel A Road surface B Transport surface C Vertical groove

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Heiji Fukutake 1-1-1 Motoda Kida, Neyagawa-shi, Osaka F-term in EXEDY Corporation (Reference) 3D050 AA01 BB01 CC02 DD03 EE08 EE14 JJ01 KK03

Claims (10)

[Claims] A caster body; a wheel supported by the caster body; rolling on the road surface together with the wheel; and falling on a transport surface of a transport device into a groove provided on the transport surface to rotate the wheel. A caster with an automatic locking mechanism, comprising: a slider that is supported by the caster body so as to be vertically movable; and a sensor wheel that is connected to the slider and the sensor wheel is provided in the groove. A locking member that locks in a rotational direction with respect to a part of the wheel when it falls, an annular grounding wheel that is arranged outside the slider, and a plurality of grounding wheels that are arranged between the slider and the grounding wheel. A caster with an automatic locking mechanism, comprising: 2. The caster according to claim 1, wherein the plurality of bearings are arranged at equal intervals in a circumferential direction. 3. The bearing is a rolling bearing in which a rolling element is held between an inner ring and an outer ring, wherein the inner ring is fixed to the slider, and the outer ring supports an inner peripheral portion of the ground wheel. The caster according to claim 1 or 2, wherein 4. The lock member according to claim 1, wherein the lock member is disposed between two of the plurality of bearings in a circumferential direction.
The caster according to any of the above. 5. The lock member is supported on the caster body so as to be vertically movable and non-rotatable, and rotates a part of the wheel and the caster body when the sensor wheel falls into the groove. 5. The method as claimed in claim 1, wherein the connection is made in a direction.
The caster according to any of the above. 6. The caster according to claim 1, further comprising a spring disposed between said caster body and said slider, for urging said slider downward with respect to said caster body. 7. The caster according to claim 6, wherein the spring is disposed between two of the plurality of bearings in a circumferential direction. 8. The wheel is provided on both sides of the sensor wheel, and the lock member is engaged with a part of the two wheels in a rotational direction when the sensor wheel falls into the groove. The caster according to any one of claims 1 to 7, which stops. 9. The caster according to claim 1, wherein the wheel has a recess into which the lock member can enter. 10. A hand cart comprising: a cart body; and a caster according to claim 1, which is attached to a lower portion of the cart body.