Shopping cart

Abstract

To provide a carry cart that can obtain proper cushioning function through a shock-absorbing device. [Solution] The carry cart CC comprises a front wheel 32, a rear wheel 34, a loading platform 20 on which the transported object C1 is placed, and a handle portion 30 that extends vertically, with its intermediate vertical portion connected to the loading platform 20, and which the user grips when walking. The carry cart CC is provided between the lower end portion of the handle portion 30 and the front wheel 32, and has a cushioning member made of an elastic material, and is equipped with a shock absorber 36 that mitigates the impact applied to the front wheel 32 through the compressive elastic deformation of the cushioning member. The center of gravity G1 of the carry cart CC is set behind the connecting portion 29 between the loading platform 20 and the handle portion 30.

Description

Technical Field

[0001] The present invention relates to a carrier cart.

Background Art

[0002] Conventionally, a cart for carrying luggage, so-called a carrier cart, has been put into practical use (for example, Patent Document 1). The carrier cart described in Patent Document 1 includes a plurality of wheels that roll on the road surface by rotating around an axle, a loading platform on which an object to be carried such as luggage is placed, and a handle portion that extends vertically at an intermediate position in the front-rear direction of the loading platform. This carrier cart is used by placing an object to be carried on the front side of the handle portion on the loading platform and pushing the object from the rear side while gripping the handle portion in that state.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Here, in order to improve the running performance of the carrier cart, it is conceivable to provide a shock absorber between the front wheel disposed on the front side among the above wheels and the loading platform to mitigate the impact applied to the front wheel from the road surface. In this case, displacement of the front wheel upward is allowed through deformation of the shock absorber, specifically, a shock absorbing member made of an elastic material. Therefore, it becomes possible to easily overcome a step or suppress the carrier cart from falling forward when running on a step.

[0005] However, in the above-mentioned carry cart, since the goods to be transported are placed on the front part of the platform, the weight of the goods tends to concentrate on the front wheels more than the rear wheels. Therefore, when goods are placed on the platform, there is a risk that the shock-absorbing members of the shock absorbers installed on the front wheels may become elastically deformed due to the weight of the goods. If the carry cart is driven in this state, there is a risk that the shock absorbers will not be able to adequately provide shock absorption when the carry cart encounters a step or other obstacle. [Means for solving the problem]

[0006] A carry cart to solve the above problems comprises a front wheel, a rear wheel, a platform on which objects to be transported are placed, and a handle portion that extends vertically, with its intermediate vertical portion connected to the platform, and which is gripped by the user when walking. The carry cart has a cushioning member made of an elastic material provided between the lower end portion of the handle portion and the front wheel, and is equipped with a cushioning device that mitigates the impact applied to the front wheel through the elastic deformation of the cushioning member, and the center of gravity of the carry cart is set behind the connection portion between the platform and the handle portion. [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 shows one embodiment of a carry cart, and is a schematic side view of the carry cart in a state where the front wheels are in contact with the rear corner of a step and the cart is loaded. [Figure 2] Figure 2 is a perspective view of the carry cart according to the above embodiment. [Figure 3] Figure 3 is a bottom view of the carry cart according to the above embodiment. [Figure 4] Figure 4 is a side view of the carry cart of the above embodiment in an empty state. [Figure 5] Figure 5 is a block diagram showing the electrical circuit structure of the carry cart according to the above embodiment. [Figure 6] Figure 6 is a partial perspective view showing an enlarged portion of Figure 2. [Figure 7]Figure 7 is an exploded perspective view of the front wheel, front axle, link member, arm, and elastic part shown in Figure 6. [Figure 8] Figure 8 is a partial side cross-sectional view of the wheel and its surrounding area in the above embodiment. [Figure 9] Figure 9 is a partial side view of the carry cart in the above embodiment, showing the front wheels being lifted. [Figure 10] Figure 10 is a schematic side view of a carry cart in the above embodiment in which the front wheels roll along the top surface of a step. [Modes for carrying out the invention]

[0008] Below, one embodiment of the carry cart will be described with reference to the drawings. As shown in Figure 1, the carry cart CC comprises front wheels 32 and rear wheels 34 which are wheels that roll on the road surface 10, a loading platform 20 on which the items to be transported C1 such as luggage are placed, and a handle 30 which is gripped and operated by the user of the carry cart CC.

[0009] The carry cart CC moves forward in the direction of travel due to the rolling motion of the front wheels 32 and rear wheels 34. In this embodiment, the direction of travel is from right to left in each figure. The forward direction in the direction of travel is to the left in each figure.

[0010] In the following description, the forward direction of the carry cart CC will be referred to as "forward," and the reverse direction as "rear." The vertical direction refers to the up and down direction of the carry cart CC, and the left and right direction is the direction perpendicular to both the forward and vertical directions. The left and right direction is the width direction of the carry cart CC and coincides with the left and right direction when the carry cart CC is moving forward.

[0011] The road surface 10 on which the carry cart CC travels has a convex step 12. Here, in order to distinguish the convex step 12 from other parts of the road surface 10, the latter will be referred to as the general road surface 11. The upper surface of the step 12 will be referred to as the top surface 13, and the rear upper corner of the step 12 will be referred to as the rear corner 14. For the sake of simplicity, here we will assume that both the general road surface 11 and the top surface 13 are composed of horizontal surfaces.

[0012] The top surface 13 is, for example, the top surface of a sidewalk. The general road surface 11 is, for example, the top surface of a roadway. <Cargo bed 20> As shown in Figures 1 to 3, the cargo bed 20 comprises a cargo bed body 21 and a cargo bed frame 23.

[0013] The main body of the cargo bed 21 constitutes the portion on which the transported object C1 is placed. Specifically, the main body of the cargo bed 21 is a box-shaped structure with a bottom. The main body of the cargo bed 21 is equipped with a storage section 22 having an opening 22a at its upper end. The main body of the cargo bed 21 has a flange portion 21b that protrudes outward from the periphery of the opening 22a to the storage section 22. A battery 71, which serves as a power source, and a motor control unit 73 for a motor 72, which serves as a power source, are attached to the front end portion of the main body of the cargo bed 21, more specifically to the front end portion of the storage section 22. The transported object C1 can be loaded and unloaded through the opening 22a from the portion of the storage section 22 rearward from the battery 71 and the motor control unit 73.

[0014] The loading platform frame part 23 constitutes the frame of the loading platform 20. Specifically, the loading platform frame part 23 is provided at the upper part of the loading platform main body part 21, at least at a position adjacent to the front of the opening part 22a. Also, the loading platform frame part 23 is provided at the upper part of the loading platform main body part 21, at positions adjacent to both the left and right sides of the opening part 22a. The loading platform frame part 23 extends in a U-shaped manner in a plan view at the periphery of the opening part 22a. In the present embodiment, the above-mentioned loading platform main body part 21 is fixed to the loading platform frame part 23. Specifically, with the flange part 21b of the loading platform main body part 21 overlapped on the loading platform frame part 23, the flange part 21b is fastened to the loading platform frame part 23 by fastening members such as bolts and nuts.

[0015] As shown in FIGS. 1 and 2, rear wheel support parts 24 are respectively fixed to both side parts of the loading platform frame part 23 in the left-right direction. The lower part of each rear wheel support part 24 extends downward from the bottom surface 21a of the loading platform main body part 21. In the present embodiment, rear wheels 34 are attached to each of the rear wheel support parts 24.

[0016] A bearing part 25 is fixed to the central part in the left-right direction of the loading platform 20, which is the part of the loading platform frame part 23 in front of the opening part 22a. The bearing part 25 includes a pair of bearing plate parts 26 and a connecting plate part 27. The pair of bearing plate parts 26 are inclined with respect to the horizontal plane so that the front side is positioned higher. The connecting plate part 27 is inclined with respect to the vertical plane so that the upper side is positioned more rearward. The connecting plate part 27 connects the rear edges of the pair of bearing plate parts 26. And the connecting plate part 27 is fastened to the loading platform frame part 23 by fastening members 28 such as bolts and nuts. In the present embodiment, the loading platform frame part 23 extends rearward from the bearing part 25, which is the connecting part between the loading platform 20 and the handle part 30.

[0017] <Handle part 30> The handle part 30 extends in a state inclined rearward such that the upper end part is positioned more rearward than the lower end part. The handle part 30 includes a handle shaft 301 and a grip part 302.

[0018] <Handle shaft 301> As shown in Figure 1, the handle shaft 301 has a central axis CL that extends in the vertical direction. In this embodiment, the central axis CL is inclined with respect to the vertical line VL such that it is located further back towards the top. Here, the angle that the central axis CL makes with respect to the vertical line VL is called the caster angle θ1. In this embodiment, the caster angle θ1 is set to 20°.

[0019] As shown in Figures 1 and 2, the lower portion of the handle shaft 301 (hereinafter referred to as the base portion 3011) extends linearly around the central axis CL. The base portion 3011 of the handle shaft 301 is inserted through a pair of bearing plate portions 26. The base portion 3011 of the handle shaft 301 is supported by the bearing portion 25 at both bearing plate portions 26. As a result, the base portion 3011 of the handle shaft 301 is provided so as to be rotatable relative to the bearing portion 25 around the central axis CL. In other words, the bearing portion 25 supports the intermediate portion of the handle shaft 301 in the vertical direction so as to be rotatable around the central axis CL. In this embodiment, the handle shaft 301 is connected to the front upper end of the cargo bed 20 via the bearing portion 25. In this embodiment, the handle shaft 301 constitutes the steering shaft and is configured to be rotatable around the central axis CL. In this embodiment, the portion where the bearing portion 25 is connected to the cargo bed 20 by the fastening member 28 is referred to as the connection portion 29 between the cargo bed 20 and the handle portion 30.

[0020] The lower end of the handle shaft 301 protrudes below the lower bearing plate portion 26. The lower end of the handle shaft 301 is fixed to the shock absorber 36. The shock absorber 36 will be described later.

[0021] As shown in Figures 1, 3, and 4, in this embodiment, the center of gravity G1 of the carry cart CC is set behind the connecting portion 29 between the loading platform 20 and the handle portion 30. Here, in the carry cart CC, the state in which the transported object C1 with the same weight as the load capacity of the carry cart CC (for example, 10 kilograms) is placed on the loading platform 20 (the state shown in Figures 1 and 3) is defined as the "loaded state". More specifically, the "loaded state" assumes that the transported object C1 has a shape that can be placed on the loading platform 20 in a balanced manner (for example, a rectangular parallelepiped shape), and that the transported object C1 is placed on the loading platform 20 in a balanced manner without any weight unevenness in any part. In addition, in the carry cart CC, the state in which the transported object C1 is not placed on the loading platform 20 (the state shown in Figure 4) is defined as the "empty state".

[0022] In this embodiment, the center of gravity G1 of the carry cart CC is set to be behind the connecting portion 29 in both the "loaded state" shown in Figure 1 and the "unloaded state" shown in Figure 4. Specifically, the shape, weight, and arrangement of each component that makes up the carry cart CC are determined so that the center of gravity G1 of the carry cart CC is in the above position.

[0023] As shown in Figures 1 to 3, the upper part of the handle shaft 301 has a curved shaft portion 3012 and a grip shaft portion 3013. The curved shaft portion 3012 extends upward from the upper end of the base portion 3011 of the handle shaft 301 and extends in a curved shape that protrudes forward. The grip shaft portion 3013 extends rearward from the upper end of the curved shaft portion 3012 and extends in a straight line in the front-rear direction.

[0024] <Gripping part 302> The gripping portion 302 constitutes the part that is gripped by the user when using the carry cart CC. The gripping portion 302 is attached to the upper end of the handle shaft 301, more specifically to the grip shaft portion 3013. In other words, the gripping portion 302 constitutes the upper end portion of the handle portion 30.

[0025] Specifically, the grip portion 302 is cylindrical. The grip portion 302 is made of a non-slip material such as rubber. The grip portion 302 is attached to the grip shaft portion 3013 such that the peripheral wall of the grip portion 302 covers the outer surface of the grip shaft portion 3013. The grip portion 302 is positioned on the central axis CL. The user of the carry cart CC basically grips the grip portion 302. The user can rotate the handle shaft 301 by changing the orientation of the grip portion 302.

[0026] A switch 74 is provided at the lower end of the peripheral wall of the gripping portion 302. The switch 74 is a momentary operation switch operated by the user when the carry cart CC is driven by the motor 72. In this embodiment, the switch 74 is provided on the gripping portion 302 so that the operation of the switch 74 and the gripping of the gripping portion 302 can be performed simultaneously. The switch 74 is connected to the motor control unit 73.

[0027] The carry cart CC is equipped with a single front wheel 32 and a pair of rear wheels 34. Here, as shown in Figure 3, the point where the front wheel 32 makes contact with the road surface 10 is designated as "P1", the point where one of the pair of rear wheels 34 makes contact with the road surface 10 is designated as "P2", and the point where the other of the pair of rear wheels 34 makes contact with the road surface 10 is designated as "P3". Furthermore, the triangle formed by the points P1, P2, and P3 of the single front wheel 32 and the pair of rear wheels 34 is designated as the "basic triangle TB". Note that when defining the points P1, P2, and P3, the road surface 10 on which the front wheel 32 and rear wheel 34 make contact is a road surface composed of horizontal planes.

[0028] In this embodiment, a single front wheel 32 and a pair of rear wheels 34 are arranged such that the "basic triangle TB" is an isosceles triangle with the base being the line (side) connecting the contact points P2 and P3 of the pair of rear wheels 34. Furthermore, in this embodiment, as shown in Figures 1 and 3, the front wheel 32, rear wheels 34, and handle 30 are arranged such that the center of gravity G2 of the "basic triangle TB" and the gripping portion 302 of the handle 30 overlap in a plan view.

[0029] <Front wheel 32> As shown in Figures 1 and 2, the front wheel 32 is connected to the lower end of the handle shaft 301 via a shock absorber 36 located below the connecting portion 29. Specifically, the lower end of the handle shaft 301 is fixed to the link member 37 of the shock absorber 36, and the axle of the front wheel 32 (hereinafter referred to as the front axle 33) is supported by the arm 41 of the shock absorber 36. In this embodiment, the front wheel 32 is connected to the handle shaft 301 so as to rotate together with the handle shaft 301 around the central axis CL.

[0030] The front wheels 32 are drive wheels that are rotated around the front axle 33 by a motor 72, which serves as a power source, and provide propulsion to the cargo bed 20 for driving. As the motor 72, for example, an electric motor of the type that is positioned inside the wheel of the front wheel 32 and directly rotates the front wheel 32, a so-called in-wheel motor, is used.

[0031] As shown in Figure 5, the motor 72 is connected to the battery 71 and the motor control unit 73. Power is supplied to the motor 72 from the battery 71. The motor control unit 73 then controls the operation of the motor 72. The operation control of the motor 72 is performed as follows: When the switch 74 is not operated, the rotational drive of the motor 72 is stopped. At this time, the carry cart CC is in a stopped state. On the other hand, when the switch 74 is operated by the user, the rotational drive of the motor 72 is performed. At this time, the carry cart CC is in a running state.

[0032] As shown in Figures 1 to 3, both ends of the front axle 33 protrude outward on both sides in the left-right direction from the front wheel 32. <Rear wheel 34> The rear wheel 34 is rotatably supported by the rear wheel support portion 24. Specifically, the carry cart CC has a cargo bed frame portion 23 that extends rearward from the connecting portion 29 between the cargo bed 20 and the handle portion 30. The rear wheel support portion 24 is fixed to this cargo bed frame portion 23. The axle of the rear wheel 34 (hereinafter referred to as the rear axle 35) is supported in the portion of the rear wheel support portion 24 that is below the bottom surface 21a of the cargo bed body portion 21.

[0033] Each rear wheel 34 rolls on the road surface 10 by rotating around the rear axle 35. Unlike the front wheels 32, both rear wheels 34 are driven wheels that do not generate driving force. Both rear wheels 34 have a wheel diameter (diameter) similar to that of the front wheels 32. Therefore, the cargo bed 20 is positioned above the contact points P1, P2, and P3 of the front wheels 32 and rear wheels 34 with respect to the road surface 10. The bottom surface 21a of the cargo bed 20 is located higher than the lowest point of the front wheels 32 and rear wheels 34, and lower than the highest point of the front wheels 32 and rear wheels 34.

[0034] In this embodiment, the center of gravity G1 of the carry cart CC in the loaded state (shown in Figure 1) is set behind the center between the front axle 33 of the front wheel 32 and the rear axle 35 of the rear wheel 34. More specifically, the center of gravity G1 of the carry cart CC in the loaded state is set behind the center of gravity G2 of the basic triangle TB. Specifically, in this embodiment, the shape, weight, and arrangement of each component of the carry cart CC are determined so that the center of gravity G1 of the carry cart CC is at the above position.

[0035] <Buffer device 36> As shown in Figures 6 to 8, the carry cart CC is equipped with a shock absorber 36 that mitigates the impact applied to the front wheel 32. The shock absorber 36 is provided between the lower end portion of the handle 30 and the front wheel 32. The shock absorber 36 has a link member 37, an arm 41, a bracket 51, and an elastic part 55 that acts as a shock absorber.

[0036] <Link member 37> The link member 37 constitutes the part of the shock absorber 36 that is fixed to the lower end of the handle shaft 301. As described above, the lower end of the handle shaft 301 protrudes downward from the lower bearing plate portion 26. The link member 37 is attached to the lower end of the handle shaft 301 by fastening members 38 such as bolts so that it can rotate integrally with the handle shaft 301.

[0037] The link member 37 has a pair of link body portions 39 that extend vertically behind the front axle 33. The pair of link body portions 39 are spaced apart from each other in the direction in which the front axle 33 extends. The distance between the two link body portions 39 is slightly greater than the dimension of the front wheel 32 in the direction in which the front axle 33 extends.

[0038] <Arm 41> The arm 41 constitutes the part of the shock absorber 36 that is connected to the front wheel 32. The arm 41 comprises a pair of arm body portions 42 and an arm mounting portion 46. Each arm body portion 42 comprises a front plate portion 43 and a rear plate portion 45 adjacent to the rear side of the front plate portion 43 and connected to the front plate portion 43 in a bent state. The pair of arm body portions 42 are arranged on both sides of the front wheel 32 in the direction in which the front axle 33 extends. When the front wheel 32 and both rear wheels 34 are in contact with a horizontal surface, for example, a general road surface 11, the front plate portion 43 is inclined with respect to the general road surface 11 such that it is lower towards the front.

[0039] The arm 41 supports the front axle 33, thereby supporting the front wheel 32 to the link member 37. More specifically, each front plate portion 43 has a notch 44 that extends diagonally upward and backward from the front lower end of the front plate portion 43, with both the front wheel 32 and the rear wheel 34 in contact with the same horizontal plane. That is, the notch 44 of each front plate portion 43 is inclined with respect to the horizontal and vertical planes so that it is located higher towards the rear. The notch 44 of each front plate portion 43 engages with the portions of the front axle 33 that protrude outward on both sides in the left-right direction from the front wheel 32. Through these engagements, the front wheel 32 is supported by the arm 41 at both front plate portions 43.

[0040] The arm mounting section 46 is located behind the front wheel 32 and connects the rear edges of the pair of arm body sections 42. The arm 41 configured as described above is positioned between a pair of link body portions 39. More specifically, each arm body portion 42 is positioned adjacent to the inside of a link body portion 39 in the direction in which the front axle 33 extends. Each arm body portion 42 is connected by a link shaft 40 to an adjacent link body portion 39 in the direction in which the front axle 33 extends, rearward from the front wheel 32, so as to be rotatable in the vertical direction.

[0041] <Bracket 51> The bracket 51 is fixed to the link member 37. The bracket 51 comprises a bracket body 52 and a pair of mounting plate portions 53. The pair of mounting plate portions 53 are adjacent to the outside of the link body portion 39 in the direction in which the front axle 33 extends. The bracket body portion 52 is located behind the pair of link body portions 39 and behind the arm body portion 42. The bracket body portion 52 connects the rear edges of the pair of mounting plate portions 53. Each mounting plate portion 53 is attached to the link body portion 39 adjacent to it on the inside in the direction in which the front axle 33 extends by fastening members 54 such as bolts. In addition, each mounting plate portion 53 is fastened to the adjacent link body portion 39 using the link shaft 40.

[0042] <Elastic part 55> The elastic part 55 is composed of a rubber bushing comprising an elastic main body 56, a first attachment portion 57, and a second attachment portion 58. The elastic part 55 is positioned between the arm main body 42 and the bracket main body 52.

[0043] The elastic body portion 56 is formed from an elastic rubber material so as to be elastically deformable and has a central axis. Specifically, the elastic body portion 56 is bowl-shaped with an open rear surface. The outer and inner surfaces of the elastic body portion 56 have a roughly hemispherical curved surface that curves forward.

[0044] The first attachment portion 57 and the second attachment portion 58 are made of a material that is less elastically deformable than the elastic main body portion 56, such as metal, and have high strength. The first attachment portion 57 is attached to the front end of the elastic main body portion 56. The second attachment portion 58 is attached to the rear end of the elastic main body portion 56. In other words, the first attachment portion 57 and the second attachment portion 58 are connected by the elastic main body portion 56.

[0045] The elastic part 55 is attached to the bracket body 52 by fastening members 61 such as bolts at the second attachment part 58. The elastic part 55 is attached to the arm mounting part 46 by fastening members 62 such as bolts at the first attachment part 57. The elastic body 56 of the elastic part 55 configured in this way is compressed and elastically deformed as the arm 41 rotates upward with the link shaft 40 as the pivot point.

[0046] As described above, the front wheel 32 is attached to the handle shaft 301 via a shock absorber 36 including a link member 37 and an arm 41. Therefore, when the handle shaft 301 rotates about the central axis CL in response to the operation of the gripping part 302, the front wheel 32 pivots in response to that rotation. This pivot changes the direction of travel of the carry cart CC.

[0047] <Operation of this embodiment> The operation of this embodiment will now be described. As shown in Figure 1, when the front wheels 32 and both rear wheels 34 of the carry cart CC are in contact with a horizontal general road surface 11, the cargo bed 20 (bottom surface 21a) of the carry cart CC is in a nearly horizontal state.

[0048] When using the carry cart CC, the user grips the handle 302 and operates the switch 74, which triggers the motor control unit 73 to control the operation of the motor 72. At this time, the front wheels 32 are rotated forward and downward by the motor 72. This causes the front wheels 32 to generate a thrust force that moves the carry cart CC forward. This thrust force is transmitted to both rear wheels 34 via the arm 41, link member 37, handle shaft 301, and loading platform 20. Pulled forward by the transmitted thrust force, both rear wheels 34 rotate forward and downward in conjunction with the front wheels 32. At this time, the front wheels 32 and both rear wheels 34 roll forward along the general road surface 11. As a result, the carry cart CC travels forward along the general road surface 11.

[0049] Subsequently, in the example shown in Figure 1, as the carry cart CC moves, the front wheel 32 makes contact (collides) with the rear corner 14 of the step 12 from behind. This contact causes a force F to act on the front wheel 32 from the corner 14 of the road surface 10, diagonally upward and backward. This force F causes the arm 41 to rotate upward around the link axis 40, as indicated by arrow A1 in Figure 1, while compressing and elastically deforming the elastic portion 55 (see Figure 8) backward. In this embodiment, this compressive elastic deformation of the elastic portion 55 mitigates the impact caused by the front wheel 32's contact with the step 12.

[0050] As shown in Figure 9, as the carry cart CC moves forward, the front wheels 32 ride up onto the step 12. As the front wheels 32 ride up onto the step 12, the force F applied to the front wheels 32 from the corner 14 decreases. As the force F decreases, the elastic restoring force of the elastic part 55 causes the arm 41 to rotate downward around the link axis 40, as shown by arrow A2 in Figure 9. Then, as shown in Figure 10, when the front wheels 32 pass the corner 14 and ride up onto the step 12, and the force F no longer acts on the front wheels 32, the rotation of the arm 41 based on the elastic restoring force of the elastic part 55 returns the front wheels 32 to the same state as before they rode up onto the step 12.

[0051] In the carry cart CC, the object to be transported C1 is placed on the loading platform 20. Therefore, if the elastic part 55 of the shock absorber 36 is compressed and elastically deformed when the object to be transported C1 is placed on the loading platform 20, the deformation range of the elastic part 55 will be reduced accordingly, and there is a risk that the shock absorber 36 will not be able to provide sufficient shock absorption.

[0052] In this embodiment, the center of gravity G1 of the carry cart CC is set behind the connecting portion 29 between the handle 30 and the loading platform 20. Therefore, compared to the case where the center of gravity G1 of the carry cart CC is set in front of the handle 30, the weight of the transported goods C1 placed on the loading platform 20 is less likely to be applied to the front wheels 32 and the shock absorber 36. As a result, the concentration of the weight of the transported goods C1 on the loading platform 20 on the front wheels 32 and the shock absorber 36 is suppressed, and the elastic portion 55 of the shock absorber 36 is less likely to be compressed elastically deformed by the weight of the transported goods C1. Therefore, when the carry cart CC is running, the reduction in the deformation allowance for the compression elastic deformation of the elastic portion 55 can be suppressed, and an appropriate shock absorption function can be obtained from the shock absorber 36.

[0053] <Effects of this embodiment> The effects of this embodiment will now be explained. (1) The carry cart CC comprises a front wheel 32, a rear wheel 34, a platform 20 on which the transported object C1 is placed, and a handle portion 30 that extends vertically, with its intermediate vertical portion connected to the platform 20, and which the user grips when walking. The carry cart CC is provided between the lower end portion of the handle portion 30 and the front wheel 32, and has an elastic portion 55 made of an elastic material, and is equipped with a shock absorber 36 that mitigates the impact applied to the front wheel 32 through the compressive elastic deformation of the elastic portion 55. The center of gravity G1 of the carry cart CC is set behind the connection portion 29 between the platform 20 and the handle portion 30.

[0054] With the above configuration, when the carry cart CC is in motion, the reduction in the deformation allowance due to the compressive elastic deformation of the elastic part 55 can be suppressed, and thus an appropriate cushioning function can be obtained by the cushioning device 36.

[0055] (2) The handle portion 30 includes a handle shaft 301 having a central axis CL that extends in the vertical direction. The lower end portion of the handle shaft 301 is fixed to a link member 37 of the shock absorber 36. The loading platform 20 is provided with a bearing portion 25. The bearing portion 25 supports the intermediate portion of the handle shaft 301 in the vertical direction so that it can rotate around the central axis CL.

[0056] With the above configuration, the user can change the steering angle of the front wheels 32 by rotating the handle section 30, more specifically the handle shaft 301, thereby steering the carry cart CC. With the above configuration, in such a steerable carry cart CC, the shock absorber 36 can provide appropriate shock absorption during operation.

[0057] (3) The center of gravity G1 of the carry cart CC in the "loaded state" is set behind the center between the front axle 33 of the front wheel 32 and the rear axle 35 of the rear wheel 34. With the above configuration, compared to cases where the center of gravity G1 is set in the middle between the front axle 33 and the rear axle 35, or set in front of the middle, the load on the front wheels 32 and the shock absorber 36 can be reduced by placing the transported object C1 on the loading platform 20. Therefore, it is possible to suppress the elastic part 55 from being compressed and elastically deformed by the weight of the transported object C1.

[0058] (4) The handle portion 30 includes a grip portion 302 which constitutes the upper end portion of the handle portion 30 and is gripped by the user, and extends in a state of being tilted backward such that the upper end portion of the handle portion 30 is located behind the lower end portion. The carry cart CC is equipped with a single front wheel 32 and a pair of rear wheels 34. When the triangle formed by the contact points P1, P2, and P3 of the front wheel 32 and the rear wheels 34 with respect to the road surface 10 is called the basic triangle TB, the centroid G2 of the basic triangle TB and the grip portion 302 coincide in a plan view.

[0059] With the above configuration, when a user applies force to the gripping part 302 from above, the load is applied towards the part corresponding to the center of gravity G2 of the basic triangle TB. Therefore, the load applied to the handle part 30 can be evenly distributed by the three wheels, specifically the single front wheel 32 and the pair of rear wheels 34. Thus, the handle part 30 can be given the function of a "cane" to support the user.

[0060] (5) The center of gravity G1 of the carry cart CC in the "loaded state" is set further back than the center of gravity G2 of the basic triangle TB. With the above configuration, compared to the case where the center of gravity G1 coincides with the center of gravity G2 of the basic triangle TB in a plan view, or where it is in front of the center of gravity G2 of the basic triangle TB, the load on the front wheels 32 and the shock absorber 36 can be reduced by placing the transported object C1 on the loading platform 20. Therefore, it is possible to suppress the elastic part 55 from being compressed and elastically deformed by the weight of the transported object C1.

[0061] <Example of changes> The above embodiment can be implemented with the following modifications. The above embodiment and the following modifications can be combined with each other to the extent that they do not contradict each other technically.

[0062] • An alternate-type operating switch may be provided as switch 74. In this case, for example, the operation control of the motor 72 can be performed as follows: when switch 74 is turned ON, the motor 72 is driven to rotate, while when switch 74 is turned OFF, the rotation drive of the motor 72 is stopped.

[0063] The switch 74 may be provided in a part other than the gripping portion 302. For example, the switch 74 can be provided on the curved shaft portion 3012 of the handle shaft 301, or on the loading platform 20.

[0064] The inclination angle of the handle shaft 301 relative to the vertical line VL is not limited to being set to "20°", but can be arbitrarily changed to, for example, "30°", "10°", or "0°".

[0065] The gripping portion 302 may be positioned such that it does not overlap with the centroid G2 of the basic triangle TB in a plan view, for example, by positioning the gripping portion 302 in front of the centroid G2 of the basic triangle TB.

[0066] The shape of the upper part of the handle shaft 301 is not limited to a shape having a curved shaft portion 3012 and a grip shaft portion 3013, and can be changed as desired. For example, the shape of the upper part of the handle shaft 301 can be an L-shape in which the upper end portion curves toward the rear (or forward).

[0067] The handle shaft 301 may be fixed to the cargo bed frame portion 23 of the cargo bed 20. The carry cart CC according to the above embodiment can also be applied to carry carts that do not have a steering shaft. In this case, the lower end portion of the handle shaft 301 may be fixed to the cargo bed 20, and the link member 37 of the shock absorber 36 may be fixed to the cargo bed 20.

[0068] The grip portion 302 can be omitted. That is, the upper end portion of the handle portion 30 may be formed by the grip shaft portion 3013. In this case, the grip shaft portion 3013 constitutes the upper end portion of the handle portion 30 and corresponds to the grip portion that is held by the user.

[0069] • A different elastic body than the one used in the above embodiment may be used as the elastic part 55. For example, a spring such as a coil spring or a leaf spring may be used as the elastic part 55. Alternatively, an elastic body other than a spring may be used as the elastic part 55.

[0070] The number of front wheels 32 may be changed to multiple. Also, the number of rear wheels 34 may be changed to 3 or more. Furthermore, if the number of front wheels 32 is changed to multiple, the number of rear wheels 34 may be changed to 1.

[0071] The front wheel 32 may be rotationally driven by a motor provided on the outside of the front wheel 32. The front wheels 32 may be driven by a power source other than the motor 72. The rear wheels 34 may be driven wheels that are rotationally driven by a power source, and the front wheels 32 may be driven wheels. In addition, the rear wheels 34 may be driven wheels that are rotationally driven by a power source, in addition to the front wheels 32.

[0072] The front wheel 32 and the rear wheel 34 may have different wheel diameters. The main body portion 42 of the arm 41 does not necessarily have to be bent, with a front plate portion 43 and a rear plate portion 45. The main body portion 42 of the arm may, for example, be in the shape of a triangular plate.

[0073] - If the motor for the front wheel 32 is located outside the front wheel 32, or if the front wheel 32 is not driven by a motor, the front axle 33 may be separated from the front wheel 32. In this case, instead of the notch 44, a bearing hole may be formed at the front end of each arm body 42. Then, each portion of the front axle 33 that protrudes from the front wheel 32 to both sides in the direction in which the front axle 33 extends may be supported by the arm body 42 by being inserted into the bearing hole of each arm body 42. In order to insert each protruding portion of the front axle 33 from the front wheel 32 into the bearing hole of each arm body 42, the arm 41 may be divided into a pair of arm body 42.

[0074] The carry cart CC according to the above embodiment may also be applied to a non-self-propelled carry cart. In this case, the motor 72, battery 71, motor control unit 73, and switch 74 can be omitted.

[0075] The carry cart CC may have a structure that allows for the attachment of a shopping basket in a detachable manner. The carry cart CC may also have a place to hang bags such as tote bags or purses.

[0076] The carry cart CC may be equipped with a braking mechanism to stop its movement. According to this modification, when the carry cart CC is in motion, a braking force can be applied to at least one of the front wheels 32 and the rear wheels 34 to make the rotational speed variable. It is also possible to stop the rotation of the front wheels 32 and the rear wheels 34 to stop the carry cart CC from moving. The carry cart CC may also be equipped with a brake to maintain its stopped state when stopped.

[0077] The center of gravity G1 of the carry cart CC in the "loaded state" may be set so that the center of gravity G1 and the center of gravity G2 of the basic triangle TB overlap in a plan view. With this configuration, the load from placing the transported object C1 of the same weight as the load capacity on the loading platform 20 can be evenly distributed across the three wheels (specifically, a single front wheel 32 and a pair of rear wheels 34). Therefore, it is possible to suppress the concentration of the weight of the transported object C1 placed on the loading platform 20 on the front wheel 32 and the shock absorber 36, while also suppressing the increase in the weight on the rear wheels 34.

[0078] The center of gravity G1 of the carry cart CC in the "loaded state" may be set behind the midpoint between the front axle 33 of the front wheel 32 and the rear axle 35 of the rear wheel 34, and in front of the center of gravity G2 of the basic triangle TB. Alternatively, the center of gravity G1 of the carry cart CC in the "loaded state" can be set to the midpoint between the front axle 33 of the front wheel 32 and the rear axle 35 of the rear wheel 34. Furthermore, the center of gravity G1 of the carry cart CC in the "loaded state" may be set in front of the midpoint between the front axle 33 of the front wheel 32 and the rear axle 35 of the rear wheel 34, provided that the center of gravity G1 is set behind the connecting portion 29.

[0079] <Note> The technical concepts that can be understood from the above embodiments and modified examples are described below. [Note 1] A carry cart comprising a front wheel, a rear wheel, a platform on which objects to be transported are placed, and a handle portion that extends vertically and whose intermediate portion in the vertical direction is connected to the platform, and which is gripped by the user when walking, wherein the carry cart is provided between the lower end portion of the handle portion and the front wheel, and has a shock-absorbing device which has a shock-absorbing member made of an elastic material that reduces the impact applied to the front wheel through the elastic deformation of the shock-absorbing member, and the center of gravity of the carry cart is set behind the connection portion between the platform and the handle portion.

[0080] [Note 2] The carry cart as described in [Note 1], wherein the handle portion includes a handle shaft having a central axis extending in the vertical direction, the lower end portion of the handle shaft is fixed to the shock absorber, the loading platform is provided with a bearing portion, and the bearing portion supports the intermediate portion of the handle shaft in the vertical direction so as to be rotatable around the central axis.

[0081] [Note 3] The carry cart according to [Note 1] or [Note 2], wherein the center of gravity of the carry cart is set behind the center between the front axle and the rear axle when the transported object of the same weight as the load capacity of the carry cart is placed on the platform.

[0082] [Note 4] The carry cart according to any one of [Note 1] to [Note 3], wherein the handle portion includes a grip portion that constitutes the upper end portion of the handle portion and is grasped by the user, and the upper end portion extends in a state inclined backward so as to be located behind the lower end portion of the handle portion, the carry cart comprises a single front wheel and a pair of rear wheels, and when the triangle formed by the contact points of the front wheel and the rear wheels with respect to the road surface is considered as the basic triangle, the center of gravity of the basic triangle and the grip portion coincide in a plan view.

[0083] [Note 5] The carry cart is equipped with a single front wheel and a pair of rear wheels, and when the triangle formed by the contact points of the front wheel and the rear wheels with respect to the road surface is considered as the basic triangle, the center of gravity of the carry cart when the transported object of the same weight as the load capacity of the carry cart is placed on the platform is set behind the center of gravity of the basic triangle, as described in any one of [Note 1] to [Note 4]. [Explanation of Symbols]

[0084] CC...Carry Cart C1…Object to be transported G1,G2…center of gravity 20...Cargo bed 21...Main cargo bed section 21a…Bottom surface 21b…Flange section 22...Storage compartment 22a...Opening 23...Cargo bed frame section 24...Rear wheel support part 25...Bearing part 26...Bearing plate part 27…Connecting plate part 28, 38, 54, 61, 62… Fastening members 29…Connection part 30...Handle section 301... Handle shaft 3011...Base 3012...Curved shaft part 3013... Grip shaft 302...Gripping part 32…Front wheel 33…Front axle 34... Rear wheel 35…Rear axle 36…Buffer device 37…Link component 39...Link body 40... Link axis 41... Arm 42...Arm body 43...Front plate part 44... Notch 45...Rear plate part 46... Arm mounting section 51…Bracket 52…Bracket body 53…Mounting plate section 55...Elastic part 56...Elastic main body 57...First attachment part 58…Second attachment part 71…Battery 72…motor 73…Motor control unit 74... Switch

Claims

1. A carry cart comprising front wheels, rear wheels, a platform on which the transported object is placed, and a handle portion that extends vertically, with its intermediate vertical portion connected to the platform, and which is gripped by the user when walking, A shock absorber is provided between the lower end portion of the handle and the front wheel, having a shock absorber made of an elastic material, which mitigates the impact applied to the front wheel through the elastic deformation of the shock absorber, The center of gravity of the aforementioned carry cart is set behind the connection point between the cargo platform and the handle. Shopping cart.

2. The handle portion includes a handle shaft having a central axis extending in the vertical direction, The lower end portion of the handle shaft is fixed to the shock absorber, The aforementioned cargo bed is provided with a bearing section. The bearing portion supports the intermediate portion of the handle shaft in the vertical direction so that it can rotate around the central axis. The carry cart according to claim 1.

3. When the transported object, which has the same weight as the load capacity of the carry cart, is placed on the platform, the center of gravity of the carry cart is set behind the center between the front axle and the rear axle. A carry cart according to claim 1 or 2.

4. The aforementioned handle portion is It includes a gripping portion that forms the upper end of the handle and is held by the user, The upper end portion extends in a state of being tilted backward so that it is located behind the lower end portion of the handle portion. The aforementioned carry cart is It comprises a single front wheel and a pair of rear wheels, When the triangle formed by the contact points of the front and rear wheels with the road surface is considered the basic triangle, the centroid of the basic triangle and the gripping portion coincide in a plan view. A carry cart according to claim 1 or 2.

5. The aforementioned carry cart is equipped with a single front wheel and a pair of rear wheels, When the triangle formed by the points where the front and rear wheels make contact with the road surface is considered the basic triangle, When the transported object, which is the same weight as the load capacity of the carry cart, is placed on the platform, the center of gravity of the carry cart is set to be behind the center of gravity of the basic triangle. A carry cart according to claim 1 or 2.

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