JP5654890B2 - Carry cart auto return mechanism and carry cart incorporating the same - Google Patents

Description

  The present invention relates to a carry cart auto-return mechanism and a carry cart incorporating the same. More specifically, the present invention relates to an auto-return mechanism used in a carry cart having a pair of leg frames each having a wheel.

  As a conventional carry cart having a pair of leg frames each having wheels, for example, as shown in FIGS. 10A to 10C, a front wheel 103 having two wheels 103a and 103a facing left and right is rotatably supported at the lower end. A front leg frame 101 and a rear leg frame 102 that rotatably supports a rear wheel 104 having two wheels facing left and right at the lower end, and is provided on a bracket 105 attached to a position near the upper end of the front leg frame 101. The front leg frame 101 and the rear leg frame 102 are connected to each other through the swinging shaft 106 so as to be swingable, and the front leg frame 101 and the rear leg frame 102 are used in an open state (see FIG. 10A). When carrying or carrying, the front leg frame 101 and the rear leg frame 102 can be closed (see FIG. 10B). It is the (Patent Document 1).

JP 09-168414 A

  However, in the carry cart as disclosed in Patent Document 1, in order to improve convenience and the like by downsizing, the distance between the left and right opposing sides of the two wheels constituting the front wheel 103 and the rear wheel 104 is reduced as shown in FIG. 10C. When the front wheel 103 is configured to change the direction of the front wheel 103 by narrowing the distance between the left and right wheels and operating the steering wheel 107 (steering) in this way, the front wheel 103 remains tilted (in other words, the front wheel If 103 is not straight forward but facing left or right), the load is applied to the inclined side and falls down, and it is difficult to say that it is excellent in safety, convenience, and comfort.

  Here, if the distance between the left and right wheels of the two wheels constituting the front wheel 103 and the rear wheel 104 is increased or the width of the wheel itself is increased in order to ensure that it is independent, it may interfere with walking. The comfort is reduced, the direction is difficult to change and the operability is lowered, the weight is heavy and the transportation comfort is lowered, and the storage capacity is reduced because it requires a lot of space. This is not desirable because Furthermore, in order to cope with simple and easy use, further downsizing is required. Therefore, it is important that the front wheel 103 be straight forward when the hand is released from the handle 107 in order to be able to stand by itself even if the distance between the left and right wheels and the width of the wheel itself are small.

  In addition, especially when used by people who rely heavily on carry carts, such as elderly people, injured people, and disabled people, run while the wheels are facing in either the left-right direction or wobble in the left-right direction. Since it is dangerous to travel, it is also required that the wheel is straight forward and that it travels to some extent more stable than the direction of the wheel is easily changed so that control becomes difficult.

  Therefore, the present invention can automatically turn the wheel straight forward when the hand is released from the handle and can stabilize the wheel straight forward, so that the safety and convenience of using the carry cart can be achieved. It is an object of the present invention to provide a carry cart auto-return mechanism capable of improving comfort and a carry cart incorporating the same.

  In order to achieve such an object, an auto return mechanism for a carry cart according to claim 1 includes a pair of leg frames, a wheel provided below each of the pair of leg frames, a handle attached to the upper end, and a lower end of the wheel. The handle operation transmission member is used in a carry cart that includes a handle operation transmission member that is connected to the wheel frame and is capable of changing the angle of the wheel by the operation of the handle and is rotatably supported on one of the pair of leg frames. A first engagement member attached to the second engagement member, a second engagement member attached to one of the pair of leg frames, and the first engagement member in a predetermined engagement position with the second engagement member A biasing hand that biases the first engagement member or the second engagement member so that the engagement members engage with each other at a predetermined engagement position when they are deviated from The wheel at the lower end of the handle operation transmitting member is brought into a predetermined meshing position with respect to the second engagement member in a state where the direction operation force is not applied to the handle. Is going forward.

  According to a second aspect of the present invention, in the auto-return mechanism of the carry cart according to the first aspect, the first engaging member is a cylindrical member that penetrates the handle operation transmitting member, and the convex portion is formed on the edge of the peripheral wall. Alternatively, the second engagement member is a cylindrical member that penetrates the handle operation transmission member, and a concave portion or a convex portion that engages with the convex portion or the concave portion of the first engagement member at the peripheral wall edge. The concave portion and the convex portion are engaged with each other so that the first engaging member is brought into a predetermined engaging position with respect to the second engaging member.

  According to a third aspect of the present invention, in the carry cart auto-return mechanism according to the second aspect, the urging means is a compression coil spring provided on the handle operation transmitting member, and the convex portion of the first engaging member. Alternatively, the concave portion is urged so as to be pressed against the concave portion or the convex portion of the second engagement member.

  According to a fourth aspect of the present invention, in the auto return mechanism of the carry cart according to the first aspect, the pair of leg frames can be folded.

  Therefore, according to the auto-return mechanism of these carry carts, when the hand is released from the handle and no directional operation force is applied to the handle, the wheel automatically turns straight forward and the wheel goes straight. Stable in a positive state.

  According to a fifth aspect of the present invention, in the carry cart auto-return mechanism according to the fourth aspect, the carry cart can stand by itself in a state in which the pair of leg frames are folded. In this case, if the direction of the wheels cannot be controlled, the self-supporting stability will be lower when the legs are closed compared to when the pair of leg frames are open. Because it comes to face straight forward, it is sure to be independent in the closed leg state.

  A sixth aspect of the present invention is a carry cart incorporating the auto return mechanism according to any one of the first to fifth aspects. In this case, when the hand is released from the handle and the steering force is not applied to the handle, the wheel automatically turns straight forward and stabilizes in a state where the wheel is straight forward, Since the wheels automatically face straight forward, the self-supporting in the closed leg state is ensured.

  According to the carry cart auto-return mechanism and carry cart of the present invention, the wheel can be automatically turned straight forward when the steering force is not applied to the handle, and the wheel is straight forward. This makes it possible to improve the safety, convenience and comfort of carrying carts.

  Further, according to the carry cart auto-return mechanism and the carry cart of the present invention, since the self-supporting can be ensured even when the pair of leg frames are folded, the carry cart can be prevented from unexpectedly overturning, It will be possible to improve the safety, convenience and comfort of carrying carts.

It is a side view which shows the carry cart of embodiment, and is a figure which shows the state in which the front and back leg frames are open. It is a side view which shows the carry cart of embodiment, and is a figure which shows the state in which the front and back leg frames are closed. It is a bottom view which shows the carry cart of embodiment, and is a figure which shows the state in which the front and back leg frames are closed. It is a side view (partly longitudinal sectional view) showing an embodiment of an auto return mechanism of a carry cart of the present invention, and is a view showing a state where front and rear leg frames are opened. It is a figure which shows embodiment of the auto return mechanism of the carry cart of this invention, Comprising: It is an expanded longitudinal cross-sectional view of an auto return mechanism part. It is a figure which shows embodiment of the auto return mechanism of the carry cart of this invention, Comprising: It is an enlarged view of the auto return mechanism part. (A) is a front view. (B) is a side view. It is a figure which shows embodiment of the auto return mechanism of the carry cart of this invention, Comprising: It is an enlarged view of the auto return mechanism part. (A) is a front view. (B) is a side view. It is a figure which shows other embodiment of the auto return mechanism of the carry cart of this invention, Comprising: It is an enlarged view of the auto return mechanism part. (A) is a front view. (B) is a side view. It is a figure which shows other embodiment of the auto return mechanism of the carry cart of this invention, Comprising: It is an enlarged view of the auto return mechanism part. (A) is a front view. (B) is a side view. It is a side view which shows the conventional carry cart, and is a figure which shows the state in which the front and back leg frames are open. It is a side view which shows the conventional carry cart, and is a figure which shows the state in which the front and back leg frames are closed. It is a front view which shows the conventional carry cart.

  Hereinafter, the configuration of the present invention will be described in detail based on the form shown in the drawings.

  1 to 7 show an example of an embodiment of an auto return mechanism of a carry cart according to the present invention. In the present embodiment, a carry cart 1 having a front leg frame 2 and a rear leg frame 3 (also referred to as a walking aid in the case of the present embodiment) will be described as an example. Here, in this specification, up and down, front and rear, and left and right are defined with reference to a person who holds the handle 6 and uses the carry cart 1. Specifically, the direction of the arrow 31 shown in FIG. 1 is the front direction, the opposite direction is the rear direction, the direction of the arrow 32 is up, the opposite direction is down, and the direction is perpendicular to the arrows 31 and 32. The direction perpendicular to the drawing is the left-right direction.

  The carry cart auto-return mechanism of the present invention includes a pair of leg frames 2 and 3, wheels 4 and 5 provided below the pair of leg frames 2 and 3, a handle 6 attached to the upper end, and a lower end having a lower end. The angle of the wheel (front wheel 4) can be changed by the operation of the handle 6 connected to the wheel (front wheel 4 in the present embodiment), and the shaft is pivoted on one of the pair of leg frames (front leg frame 2 in the present embodiment). It is used in a carry cart including a handle operation transmission member 9 that is rotatably supported.

  The carry cart 1 of the present embodiment includes a front leg frame 2 and a rear leg frame 3 whose upper ends are connected to each other by a swinging swing shaft 2a, a pair of front tires 4a and 4a arranged opposite to each other, and these A front wheel 4 having an axle 4b provided between the opposed front tires 4a, 4a, the axle 4b being supported so as to be axially rotatable below the front leg frame 2, and a pair of rear tires arranged opposite to each other. A rear wheel 5 having 5a, 5a and an axle 5b provided between the opposed rear tires 5a, 5a, the axle 5b being supported so as to be axially rotatable below the rear leg frame 3, and a front leg frame 2, a handle 6 provided above 2, and a joint pipe 8 that is mounted between the front leg frame 2 and the rear leg frame 3.

  The front leg frame 2 has a cylindrical portion 2c having a through-hole 2b in the axial direction, and a pair of rear side walls 2d and 2d extending from the left and right sides of the cylindrical portion 2c to the rear. The pair of opposing rear side walls 2d and 2d form a recess in the axial direction that opens toward the rear leg frame 3 on the side facing the rear leg frame 3 of the front leg frame 2, that is, the rear side.

  A steering pipe 9 as a handle operation transmission member 9 that passes through the through hole 2b is inserted into the through hole 2b of the front leg frame 2. The steering pipe 9 is cylindrical and formed longer than the front leg frame 2, and is disposed at a position where the upper end portion protrudes from the upper end edge of the front leg frame 2 and the lower end portion protrudes from the lower end edge of the front leg frame 2. A handle 6 is screwed and fixed to the upper end portion of the steering pipe 9 protruding from the upper end edge of the front leg frame 2 (Note that the mounting method is not limited to screwing, and driving of a spring pin or adhesive) Adhesion or welding may also be used, as is “screwing” in the following description).

  A steering guide 11 is attached to the upper end portion of the front leg frame 2. The steering guide 11 has a cylindrical insertion portion 11a. The insertion portion 11a is inserted into the upper end portion of the front leg frame 2, and the steering pipe 9 is slidably penetrated into the through hole of the insertion portion 11a. In this state, it is screwed and fixed to the upper end of the front leg frame 2 and attached.

  On the other hand, a front wheel block 7 for supporting the axle 4b of the front wheel 4 so as to be rotatable is attached to the lower end of the steering pipe 9 protruding from the lower edge of the front leg frame 2. The front wheel block 7 is fixedly attached to the lower end of the steering pipe 9 by inserting the lower end portion of the steering pipe 9 from the upper end of the front wheel block 7 and screwing it.

  An axle 4b of the front wheel 4 is provided at a position below the steering pipe 9 so as to penetrate the front wheel block 7 so as to be axially rotatable in the left-right direction. Thereby, the front wheel 4 is attached to the lower part of the front leg frame 2 via the axle 4b so as to be rotatable.

  With the above configuration, the direction operation of the handle 6 by the user of the carry cart 1 is transmitted to the front wheel 4 via the steering pipe 9 in the through hole 2b of the front leg frame 2, and the front wheel 4 changes its direction (that is, the angle is changed). Change).

  The rear leg frame 3 is formed in a cylindrical shape, and a joint member 12 is attached to the upper end portion of the rear leg frame 3. The joint member 12 has a lower insertion portion (not visible in the drawing) inserted into the through hole in the axial direction of the rear leg frame 3 and a vertical plate extending forward to form a left and right through hole. The lower connecting portion is screwed and attached to the upper end of the rear leg frame 3 in a state where the lower insertion portion is inserted into the through hole in the axial direction of the rear leg frame 3.

  Further, a frame joint 13 for connecting the front leg frame 2 and the rear leg frame 3 to the upper end portion of the front leg frame 2 so that the front leg frame 2 and the rear leg frame 3 can swing, in other words, swinging open and close legs about the sliding swing shaft 2a. Is attached. The frame joint 13 has a front part inserted between the rear side walls 2d and 2d of the front leg frame 2 and a shaft 14 penetrating the front part of the frame joint 13 and the rear side walls 2d and 2d in the left-right direction. It is attached to the upper end of the front leg frame 2. In the present embodiment, hooks 15 for carrying luggage or the like are attached to both ends of the shaft 14 protruding left and right from both rear side walls 2d, 2d of the front leg frame 2.

  The frame joint 13 has a vertical groove 13a into which the connecting portion 12a of the joint member 12 attached to the upper end of the rear leg frame 3 is opened in the rearward direction, and opposed to the left and right side walls forming the vertical groove 13a. The swinging shaft support long grooves 13b for supporting both ends of the sliding swinging shaft 2a arranged in the left-right direction so as to be slidable (slidable) in the front-rear direction are provided on each of the surfaces (that is, the inner wall surface). Formed.

  The upper end of the rear leg frame 3 penetrates the through hole in the left and right direction of the connecting portion 12a with the connecting portion 12a of the joint member 12 inserted into the vertical groove 13a of the frame joint 13, and the swing of the frame joint 13 It is pivotally supported so as to be rotatable and slidable in the front-rear direction with respect to the frame joint 13 via a sliding rocking shaft 2a supported at both ends by the dynamic shaft support long groove 13b. Here, in a state where the front and rear leg frames 2 and 3 are folded, the rear side walls 2d and 2d of the front leg frame 2 and the rear leg frame 3 are closed without a gap, and the upper end of the rear leg frame 3 is connected to the frame joint as described above. By being pivotally supported so as to be slidable in the front-rear direction with respect to 13, it is possible to prevent injuries caused by pinching fingers or the like between the front and rear leg frames 2 and 3 when folded.

  A rear wheel holder 10 is attached to the lower end portion of the rear leg frame 3 to support the axle 5b of the rear wheel 5 so as to be rotatable. The rear wheel holder 10 includes a front mounting portion 10a and a rear axle support portion 10b. The rear wheel holder 10 is screwed in a state where the upper portion of the mounting portion 10a is inserted into the lower end portion of the rear wheel frame 3. Fixed and attached to the lower end.

  The axle 5b of the rear wheel 5 is provided so as to penetrate the axle support portion 10b of the rear wheel holder 10 so as to be rotatable in the left-right direction. Thereby, the rear wheel 5 is attached to the lower part of the rear leg frame 3 via the axle 5b so as to be rotatable.

  The joint pipe 8 is spanned between the front leg frame 2 and the rear leg frame 3 to limit the degree of opening of the front and rear leg frames 2 and 3, and includes a slide block 8a at the front end and the rear leg frame 2. A mounting block 8b is provided at the end.

  The slide block 8a has a left and right through hole and is inserted between both rear side walls 2d and 2d of the front leg frame 2. On the other hand, slide guide grooves 2e in the axial direction of the front leg frame 2 are formed on the opposite surfaces (that is, the inner wall surfaces) of the two rear side walls 2d, 2d of the front leg frame 2 so as to face each other in the left-right direction. A slide shaft 8c is provided that penetrates the through hole in the left-right direction of the slide block 8a and is inserted into the slide guide grooves 2e and 2e so that the slide guide grooves 2e and 2e can slide. Thereby, the slide block 8a is attached to the front leg frame 2 so as to be movable in the axial direction of the front leg frame 2.

  The mounting block 8b is inserted into a front-opening U-shaped mounting bracket 17 whose vertical plate-like portion extending rearward is mounted at a position near the lower end of the front surface of the rear leg frame 3, and a left-right swing shaft passing through the mounting block 8b. Is connected to the rear leg frame 3 so as to be rotatable.

  A stopper block 16 for restricting the downward movement of the slide block 8a at the front end of the joint pipe 8 is attached between both rear side walls 2d, 2d of the front leg frame 2. Here, the mounting position of the stopper block 16 is adjusted so that the slide block 8a that can move in the axial direction of the frame is stopped at a higher position in the horizontal positional relationship than the mounting block 8b. In the present embodiment, in order to ensure stability during traveling with the front and rear leg frames 2 and 3 open, simply lifting the carry cart 1 (in other words, the front and rear leg frames 2 and 3 The horizontal positional relationship between the slide block 8a and the mounting block 8b is adjusted so that the front and rear leg frames 2 and 3 will not be closed without permission (even if the force to push the legs against the running surface is weakened). Yes. Specifically, the joint pipe 8 is adjusted to be perpendicular to the front leg frame 2.

  With the above-described configuration, the joint pipe 8 is connected to the front leg frame 2 so as to be swingable and movable in the frame axial direction, and the rear end is connected to the rear leg frame 3 so as to be swingable. The Further, the downward movement of the slide block 8 a at the front end of the joint pipe 8 in the frame axial direction is restricted by the stopper block 16. As a result, the degree of leg opening between the front leg frame 2 and the rear leg frame 3 is limited to an appropriate range, and the leg open state at the appropriate degree is maintained.

  When the handle 6 is lifted from the state where the front and rear leg frames 2 and 3 are open, a force is applied to the front and rear leg frames 2 and 3 to close each other by its own weight. Then, when the slide block 8a side of the joint pipe 8 is pushed up a little, the front and rear leg frames 2 and 3 are closed by the dead weight. At this time, the slide block 8a moves upward in accordance with the closing operation of the front and rear leg frames 2 and 3, and the joint pipe 8 does not hinder the closing operation of the front and rear leg frames 2 and 3. Note that the carry cart 1 of the present embodiment has two wheels 4a, 4a, 5a, 5a constituting the front wheels 4 and the rear wheels 5, respectively, as shown in FIG. Since the width and the distance between the left and right sides of each of the front wheels 4 are narrow, there is a possibility that the front wheels 4 may fall if the angle is changed with respect to the straight forward direction. On the other hand, if the front wheels 4 face straight forward, the front and rear leg frames 2 , 3 can be self-supporting even when closed. When the front and rear leg frames 2 and 3 are closed, the joint pipe 8 is accommodated between both rear side walls 2 d and 2 d of the front leg frame 2.

  The carry cart auto-return mechanism of the present invention includes a first engagement member 21 attached to a handle operation transmission member (the steering pipe 9 in this embodiment) and one of a pair of leg frames (in this embodiment). When the second engagement member 22 attached to the front leg frame 2) and the first engagement member 21 are deviated from the predetermined engagement position with respect to the second engagement member 22, these engagement members 21 , 22 and the urging means 23 for urging the first engagement member 21 so as to engage with each other at a predetermined engagement position, and in the state where no directional operation force is applied to the handle 6, the second By bringing the first engagement member 21 to a predetermined engagement position with respect to the engagement member 22, the wheel (the front wheel 4 in this embodiment) at the lower end of the handle operation transmission member (steering pipe 9) is moved forward. It is Kassel thing.

  In the present embodiment, a first cam 21 as a first engagement member is provided at a position near the lower end of the steering pipe 9. The first cam 21 is formed in a cylindrical shape having a convex portion 21a extending in the axial direction at a part of the lower end edge of the peripheral wall, and the steering pipe 9 is passed through the through-hole in the cylindrical axial direction. It is provided so as to be axially slidable with respect to the pipe 9.

  A long hole 21 b in the axial direction is provided in the peripheral wall of the first cam 21, and a guide projection 9 a is attached to the steering pipe 9. Then, the guide projection 9a is fitted in the long hole 21b in the axial direction so that the first cam 21 does not rotate in the circumferential direction relative to the steering pipe 9 (that is, the shaft rotates). When the direction is operated, the first cam 21 rotates together with the steering pipe 9.

  A ring-shaped spring receiver 20 is attached above the first cam 21. The spring receiver 20 is attached to the steering pipe 9 by screwing the steering pipe 9 through the through hole.

  Then, as an urging means for urging the first cam 21 against the second cam 22 between the first cam 21 and the spring receiver 20, the steering pipe 9 is penetrated and the compression coil spring 23. Is interposed.

  A second cam 22 as a second engaging member is attached to the lower end portion of the through hole 2b of the front leg frame 2. The second cam 22 has a cylindrical portion 22a in which a concave portion 22b is formed in a part of the upper edge of the peripheral wall, and the cylindrical portion 22a is inserted into the lower end portion of the through hole 2b of the front leg frame 2 and the cylindrical portion. The steering pipe 9 is slidably passed through the through hole 22a and attached by screwing. Note that the steering pipe 9 as a handle operation transmission member of the present embodiment is supported on the front leg frame 2 by an upper end side steering guide 11 and a lower end side second cam 22 so as to be axially rotatable.

  The first cam 21 and the second cam 22 stabilize the wheel (front wheel 4 in the present embodiment) in a state of facing straight forward, and the handle 6 in a state in which the wheel remains facing in either the left or right direction. This is to automatically turn the wheel straight when the hand is released. In the present embodiment, in order to realize the above-described operation, the first cam 21 is provided with a convex portion 21 a and the concave portion 22 b is formed in the second cam 22 that meshes with the first cam 21.

  In the present embodiment, the convex portion 21a of the first cam 21 is formed such that the front view (front view) is triangular and the peripheral wall extends downward over a range approximately half of the lower end edge of the cylindrical peripheral wall.

  Further, in the present embodiment, the concave portion 22b of the second cam 22 is formed as an inverted triangle with the peripheral wall being cut downwards in a front view over a range approximately half of the upper edge of the peripheral wall of the cylindrical portion 22a. .

  The first cam 21 and the second cam 22 are such that the front end of the convex portion 21a of the first cam is that of the second cam when the front wheel 4 (and the handle 6) faces straight forward. Position and dimensions including the spring receiver 20 and the compression coil spring 23 so as to be positioned at the lowermost part (deepest part) of the recess 22b and pressed with an appropriate force (predetermined meshing position; see FIG. 5). Etc. are adjusted and arranged. The appropriate force by which the convex portion 21a of the first cam is pressed against the concave portion 22b of the second cam is that the front wheel 4 is staggered in the left-right direction when the handle 6 is pushed forward by pushing the carry cart 1. It can be stabilized straight and forward, and the steering wheel 9 and the first cam 21 are rotated to change the angle of the front wheel 4 by changing the direction of travel by changing the direction of the steering wheel 9 and the first cam 21. This means the pressing force with no resistance.

  The operation of the first cam 21 and the second cam 22 as an auto return mechanism will be described below.

  When the steering wheel 6 is operated to change the angle of the front wheel 4 and the steering pipe 9 rotates axially, the first cam 21 rotates axially via the guide protrusion 9a and the long hole 21b. At this time, the convex portion 21a of the first cam slides up the upper end slope of the concave portion 22b of the second cam (in other words, operates like an end face cam), and the first cam 21 is the steering pipe. 9 moves upward in the axial direction. Then, when the first cam 21 moves upward, the compression coil spring 23 is compressed, and the spring force of the extending action is stored in the spring 23.

  Then, when the hand is released from the handle 6 while the front wheel 4 is straightly changed with respect to the forward direction, the extension spring force stored in the compression coil spring 23 is released and the first cam 21 is moved. Press down. At this time, since the convex portion 21a of the first cam slides down the upper end slope of the concave portion 22b of the second cam, the first cam 21 moves downward in the axial direction of the steering pipe 9 while rotating the shaft. To do. And when the front-end | tip part of the convex part 21a of a 1st cam reaches | attains the lowest part (deepest part) of the recessed part 22b of a 2nd cam, the convex part 21a will be pressed on the recessed part 22b (predetermined meshing position). The movement of the first cam 21 stops.

  In the above case, when the first cam 21 rotates, the steering pipe 9 also rotates. When the movement of the first cam 21 stops, the rotation of the steering pipe 9 also stops. That is, when the hand is released from the handle 6 with the front wheel 4 facing left or right, the compression coil spring 23, the first cam projection 21a, and the second cam recess 22b As a result, the first cam 21 rotates axially so that the front wheel 4 faces forward, and then the movement of the first cam 21 stops and the front wheel 4 keeps facing forward. Operation as an auto return mechanism is realized.

  According to the auto return mechanism of the carry cart configured as described above, the first cam 21 and the second cam 22 are fixed with a certain amount of resistance at a predetermined meshing position. The front wheel 4 can be stabilized in a straight forward direction without wobbling in the left-right direction, and the carry cart 1 can be stably driven. Further, when the first cam 21 and the second cam 22 are deviated from the predetermined meshing position, they automatically return to the predetermined meshing position. You can automatically turn straight ahead. For this reason, when the hand is released from the handle 6, the front wheel 4 can be returned straight forward even if the angle of the front wheel 4 is changed with respect to straight forward. When the front wheel 4 is changed in angle with respect to the straight forward direction as in the present embodiment, there is a possibility that the vehicle falls over while the carry cart 1 can stand on its own if the front wheel 4 is straight forward. In this case, the carry cart 1 can be made independent.

  In addition, although the above-mentioned form is an example of the suitable form of this invention, it is not limited to this, A various deformation | transformation implementation is possible in the range which does not deviate from the summary of this invention. For example, in the above-described embodiment, the carry cart 1 having the overall structure shown in FIGS. 1 to 4 is taken as an example of the carry cart to which the auto return mechanism of the present invention is applied. However, the carry cart to which the present invention can be applied is It is not limited to the carry cart 1. Specifically, for example, in the above-described embodiment, the carry cart 1 having a total of four tires (4a, 4a, 5a, 5a), two front and rear, is given as an example. The tire may be composed of a single tire, and the front wheel 4 and the rear wheel 5 are wide (specifically, wide enough to support the front and rear leg frames 2, 3, etc.). It may be composed of one piece. Also in this case, the wheels (one or two tires) interlocking with the steering wheel direction operation are automatically turned straight forward by the auto-return mechanism of the present invention to ensure self-supporting by three or two tires. Can be. Further, it may be a carry cart having five or more tires. Specifically, for example, each of the tires (4a, 4a, 5a, 5a) in the above-described embodiment is constituted by two tires facing left and right. A carry cart having a total of eight tires may be used.

  In the above-described embodiment, the carry cart 1 that can stand by itself is exemplified. However, the auto return mechanism of the present invention may be applied to a carry cart that does not stand by itself. Therefore, specifically, for example, a carry cart in which both the front wheels 4 and the rear wheels 5 are configured by one narrow tire may be used. Also in this case, the wheels can be stabilized in a straight forward direction without wobbling in the left-right direction, and the carry cart can be stably driven.

  Further, in the above-described embodiment, the carry cart 1 in which the upper end portions of the front leg frame 2 and the rear leg frame 3 are connected so as to be swingable and can be opened and closed is described as an example. The leg frame 3 may be fixedly connected in an open leg state, or may be connected to places other than the upper ends of the front and rear leg frames 2 and 3. Furthermore, the front leg frame 2 and the rear leg frame 3 may not be directly connected to each other. For example, the front and rear leg frames 2 are interposed via a lateral member disposed between the front leg frame 2 and the rear leg frame 3. , 3 may be connected.

  In the above-described embodiment, the carry cart is also referred to as a walking aid, but the carry cart in the present invention is not limited to what is called a walking aid, and is equipped with a silver car or a caster. The thing of the structure called a cane or a shopping cart is also included.

  Further, in the above-described embodiment, the steering pipe 9 as a handle operation transmission member is supported by the front leg frame 2 so as to be axially rotatable, the direction of the front wheel 4 is operated by the handle 6, and the components of the auto return mechanism are moved to the front leg frame 2 side. However, the application form of the present invention is not limited to this, and the steering pipe 9 is supported by the rear leg frame 3 so as to be axially rotatable, and the rear wheel 5 is operated in the direction by the handle 6. The components of the auto return mechanism may be disposed on the rear leg frame 3 side. Even in this case, the same effects as those of the above-described embodiment can be exhibited.

  In the above-described embodiment, the auto return mechanism is arranged on the lower end side of the front leg frame 2, but the arrangement of the auto return mechanism is not limited to the lower end side of the front leg frame 2. Any position is acceptable.

  In the above-described embodiment, the first cam 21 as the first engaging member is provided with the convex portion 21a and the second cam 22 as the second engaging member is provided with the concave portion 22b. Not limited to this, the first cam 21 may be provided with a recess and the second cam 22 may be provided with a protrusion.

  Further, in the above-described embodiment, the convex portion 21a of the first cam 21 as the first engaging member is formed in a triangular shape in front view, and the concave portion 22b of the second cam 22 as the second engaging member is in front. The shape of the convex part and the concave part is not limited to a specific shape as long as it can slide on the contact point / contact surface of both, but for example, a semicircular shape or a parabolic shape. There may be.

  Further, the forms and configurations of the first engagement member and the second engagement member are not limited to those of the above-described embodiment. For example, one of the engagement members may be formed as a simple convex portion. Specifically, as shown in FIG. 8, the first engagement member 21 is formed in the same manner as in the above-described embodiment, The two engaging members 22 are round button-like protrusions 22 that are disposed at both end positions of the convex portion 21a at predetermined engagement positions of the engaging members 21 and 22, and are attached to the inner peripheral surface of the front leg frame 2. Anyway. Further, as shown in FIG. 9, a recess 21 c is formed in the first engagement member 21, and the second engagement member 22 is placed at the uppermost portion of the recess 21 c at a predetermined engagement position of both engagement members 21 and 22. A round button-like protrusion 22 attached to the inner peripheral surface of the front leg frame 2 may be arranged at the (deepest part) position. Note that the second engagement member 22 in the above-described embodiment also functions to support the steering pipe 9 together with the steering guide 11 on the front leg frame 2 so as to be rotatable about the shaft. As shown in FIG. 9, when the projections on the inner peripheral surface of the front leg frame 2 are used, a member for supporting the steering pipe 9 on the front leg frame 2 so as to be rotatable about the front leg frame 2 is used instead of the second engagement member 22. Provided on the lower end side.

  In the above-described embodiment, the spring receiver 20 is attached to the steering pipe 9 and the first cam 21 and the spring receiver 20 are biased as a biasing means for biasing the first cam 21 in the direction in which the first cam 21 is pressed against the second cam 22. Although the compression coil spring 23 is interposed therebetween, the configuration of the urging means is not limited to this. For example, the spring receiver 20 may be attached to the inner peripheral surface of the front leg frame 2, or a leaf spring may be interposed between the first cam 21 and the spring receiver 20.

  Further, in the above-described embodiment, the first engagement member 21 attached to the steering pipe 9 so as to be slidable in the axial direction is pressed against the second engagement member 22 fixedly attached to the front leg frame 2 in a compression direction. In contrast to this, the first engagement member 21 is fixedly attached to the steering pipe 9 and the second engagement member 22 is axially attached to the front leg frame 2. The second engagement member 22 may be slidably attached and urged by the compression coil spring 23 in a direction in which the second engagement member 22 is pressed against the first engagement member 21. Specifically, the second engaging member 22 in the above-described embodiment is slid in the axial direction with the lower member that supports the steering pipe 9 on the front leg frame 2 so as to be capable of rotating on the shaft and serves as the spring receiver 20. The upper member that moves and engages with the first engaging member 21 may be divided and the urging means 23 may be interposed between the lower member and the upper member.

DESCRIPTION OF SYMBOLS 1 Carry cart 2 Front leg frame 2a Sliding rocking shaft 3 Rear leg frame 4 Front wheel 5 Rear wheel 6 Handle 9 Handle operation transmission member 21 First engagement member 22 Second engagement member

Claims (6)

  A pair of leg frames; a wheel provided below each of the pair of leg frames; a handle attached to the upper end; and a lower end connected to the wheel; and the angle of the wheel can be changed by operating the handle; A first engagement member attached to the handle operation transmission member and the pair of leg frames are used in a carry cart including a handle operation transmission member that is rotatably supported on one of the pair of leg frames. A second engagement member attached to one of the first engagement member and the first engagement member when the first engagement member is displaced from a predetermined engagement position with respect to the second engagement member. Urging means for urging the first engagement member or the second engagement member so as to engage with each other at a predetermined engagement position; In a state where no force is applied, the wheel at the lower end of the handle operation transmission member is directed forward by moving the first engagement member to the predetermined engagement position with respect to the second engagement member. Carry cart auto return mechanism.   The first engaging member is a cylindrical member that allows the handle operation transmitting member to pass therethrough, and has a convex portion or a concave portion at an edge of the peripheral wall, and the second engaging member allows the handle operation transmitting member to pass therethrough. The cylindrical member is provided with a concave portion or a convex portion that engages with the convex portion or the concave portion of the first engaging member at the edge of the peripheral wall, and the second engaging member is engaged with the concave portion and the convex portion. 2. The automatic return mechanism for a carry cart according to claim 1, wherein the first engaging member is brought into the predetermined engagement position with respect to a joint member.   The biasing means is a compression coil spring provided on the handle operation transmitting member, and is applied so as to press the convex portion or concave portion of the first engaging member against the concave portion or convex portion of the second engaging member. 3. The automatic return mechanism for a carry cart according to claim 2, wherein the automatic return mechanism is provided.   2. The carry cart auto-return mechanism according to claim 1, wherein the pair of leg frames are foldable.   5. The carry cart auto-return mechanism according to claim 4, wherein the carry cart is capable of self-supporting in a state in which the pair of leg frames are folded.   A carry cart incorporating the auto return mechanism according to any one of claims 1 to 5.

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