Carry cart

Abstract

A carry cart (CC) comprises: a front wheel (32); two rear wheels (34); a load bed (20) on which an object (C1) to be transported is placed; and a handle portion (30) which extends in the vertical direction, which has an intermediate portion that extends in the vertical direction and is connected to the load bed (20), and which is gripped by a user during walking. The carry cart (CC) comprises a shock-absorbing device (36) which is provided between the front wheel (32) and the lower end portion of the handle portion (30). The shock-absorbing device (36) has a shock-absorbing member which is composed of an elastic material and which mitigates, through compressive elastic deformation of the shock-absorbing member, an impact applied to the front wheel (32). The center of gravity (G1) of the carry cart (CC) is set rearward of a connection portion (29) between the load bed (20) and the handle portion (30).

Description

Carry cart

[0001] FIELD OF THE DISCLOSURE The present disclosure relates to a carry cart.

[0002] Conventionally, carts for transporting luggage, known as carry carts, have been in practical use (see, for example, Patent Document 1). The carry cart described in Patent Document 1 includes a plurality of wheels that rotate around axles to roll on a road surface, a loading platform on which an object to be transported, such as luggage, is placed, and a handle extending vertically at a midpoint between the front and rear of the loading platform. This carry cart is used by placing the object to be transported on the loading platform forward of the handle, and then gripping the handle and pushing the cart from behind to transport the object.

[0003] Japanese Patent Application Laid-Open No. 2006-76468

[0004] To improve the running performance of a trolley, a shock absorber can be installed between the front wheels (the wheels located at the front) and the platform to absorb the impact from the road surface on the front wheels. In this case, the shock absorber, specifically the shock absorber made of an elastic material, allows the front wheels to move upward through deformation. This allows the trolley to easily overcome steps and prevents the trolley from tipping forward when traveling over steps.

[0005] However, in the above-mentioned carry cart, since the load is placed on the front part of the platform, the weight of the load tends to be concentrated on the front wheels rather than the rear wheels. Therefore, when the load is placed on the platform, the weight of the load may cause the shock absorber of the shock absorber attached to the front wheels to become elastically deformed. If the carry cart is traveling in this state, the shock absorber may not be able to provide sufficient shock absorption when the carry cart approaches a step, for example.

[0006] One aspect of the present disclosure provides a carry cart. The carry cart includes front wheels, rear wheels, a platform on which an object to be carried is placed, and a handle that extends vertically and is connected to the platform at its vertically intermediate portion, and that a user grasps when walking. The carry cart also includes a shock absorber provided between the lower end portion of the handle and the front wheel, the shock absorber having a shock absorber member made of an elastic material, and absorbing impacts applied to the front wheel through elastic deformation of the shock absorber member. The center of gravity of the carry cart is located rearward of the connection between the platform and the handle.

[0007] FIG. 1 is a diagram showing one embodiment of a carry cart, and is a schematic side view of the carry cart in a loaded state with the front wheel in contact with the rear corner of a step. FIG. 2 is a perspective view of the carry cart of the embodiment. FIG. 3 is a bottom view of the carry cart of the embodiment. FIG. 4 is a side view of the carry cart of the embodiment in an empty state. FIG. 5 is a block diagram showing the electrical circuit structure of the carry cart of the embodiment. FIG. 6 is a partial perspective view showing an enlarged portion of FIG. 2. FIG. 7 is an exploded perspective view of the front wheel, front axle, link member, arm, and elastic part in FIG. 6. FIG. 8 is a partial side cross-sectional view of the wheel and its surrounding area in the embodiment. FIG. 9 is a partial side view of the carry cart in the embodiment with the front wheel being lifted. FIG. 10 is a schematic side view of the carry cart in the embodiment with the front wheel rolling on the top surface of a step.

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

[0009] The carry cart CC travels forward in the direction of travel by the rolling of the front wheels 32 and the rear wheels 34. In this embodiment, the direction of travel is from right to left in each drawing. The forward direction in the direction of travel is the left side in each drawing.

[0010] In the following description, the forward direction of the carry cart CC is referred to as the front, and the backward direction is referred to as the rear. Furthermore, the up-down direction refers to the vertical direction of the carry cart CC, and the left-right direction refers to the direction perpendicular to both the forward direction and the up-down direction. The left-right direction refers to the width direction of the carry cart CC, and corresponds to the left-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 portions of the road surface 10 that are not the step 12, the latter will be referred to as a general road surface 11. The upper surface of the step 12 will be referred to as a top surface 13, and the upper rear corner of the step 12 will be referred to as a rear corner 14. For ease of explanation, it is assumed here that both the general road surface 11 and the top surface 13 are horizontal surfaces.

[0012] The top surface 13 is, for example, the upper surface of a sidewalk. The general road surface 11 is, for example, the upper surface of a roadway. <Loading Platform 20> As shown in Figures 1 to 3, the loading platform 20 includes a loading platform main body 21 and a loading platform frame 23.

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

[0014] The bed frame portion 23 forms the frame of the bed 20. Specifically, the bed frame portion 23 is provided on the upper portion of the bed main body portion 21, at least in a position adjacent to the front of the opening 22a. The bed frame portion 23 is also provided on the upper portion of the bed main body portion 21, in positions adjacent to both the left and right sides of the opening 22a. The bed frame portion 23 extends around the periphery of the opening 22a so as to form a U-shape in a plan view. In this embodiment, the bed main body portion 21 is fixed to the bed frame portion 23. More specifically, with the flange portion 21b of the bed main body portion 21 overlapping the bed frame portion 23, the flange portion 21b is fastened to the bed frame portion 23 by fastening members such as bolts and nuts.

[0015] 1 and 2, a rear wheel support portion 24 is fixed to each of the left and right sides of the bed frame portion 23. The lower portion of each rear wheel support portion 24 extends downward below the bottom surface 21a of the bed main body portion 21. In this embodiment, a rear wheel 34 is attached to each rear wheel support portion 24.

[0016] A bearing 25 is fixed to the bed frame 23 in a portion forward of the opening 22a and in the center of the bed 20 in the left-right direction. The bearing 25 includes a pair of bearing plates 26 and a connecting plate 27. The pair of bearing plates 26 are inclined with respect to the horizontal plane so that they are positioned higher toward the front. The connecting plate 27 is inclined with respect to the vertical plane so that they are positioned further rearward toward the top. The connecting plate 27 connects the rear edges of the pair of bearing plates 26 to each other. The connecting plate 27 is fastened to the bed frame 23 with fastening members 28 such as bolts and nuts. In this embodiment, the bed frame 23 extends rearward from the bearing 25, which is the connecting portion between the bed 20 and the handle 30.

[0017] The handle portion 30 extends in a rearwardly inclined state so that the upper end portion is located rearward of the lower end portion. The handle portion 30 includes a handle shaft 301 and a grip portion 302.

[0018] <Steering Wheel Shaft 301> As shown in Figure 1, the steering wheel 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 so that the upper part of the central axis CL is positioned further rearward. Here, the angle that the central axis CL makes with the vertical line VL is referred to as the caster angle θ1. In this embodiment, the caster angle θ1 is set to 20°.

[0019] As shown in FIGS. 1 and 2 , a lower portion of the handle shaft 301 (hereinafter referred to as the base 3011) extends linearly around the central axis CL. The base 3011 of the handle shaft 301 is inserted through a pair of bearing plates 26. The base 3011 of the handle shaft 301 is supported by the bearings 25 at both bearing plates 26. This allows the base 3011 of the handle shaft 301 to rotate relative to the bearings 25 around the central axis CL. In other words, the bearings 25 support a middle portion of the handle shaft 301 in the up-down direction so that the middle portion is 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 bearings 25. In this embodiment, the handle shaft 301 forms a 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 loading platform 20 by the fastening member 28 is referred to as a connecting portion 29 between the loading platform 20 and the handle portion 30 .

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

[0021] As shown in FIGS. 1, 3, and 4, in this embodiment, the center of gravity G1 of the carry cart CC is located rearward of the connecting portion 29 between the platform 20 and the handle 30. Here, the state of the carry cart CC in which a load C1 of the same weight as the load capacity (e.g., 10 kilograms) is placed on the platform 20 (the state shown in FIGS. 1 and 3) is referred to as the "loaded state." Specifically, the "loaded state" refers to a state in which the load C1 has a shape (e.g., a rectangular parallelepiped) that allows it to be placed on the platform 20 in a balanced manner, and the load C1 has no weight imbalance at each part. Furthermore, the state of the carry cart CC in which the load C1 is not placed on the platform 20 (the state shown in FIG. 4) is referred to as the "unloaded state."

[0022] In this embodiment, in both the "loaded state" shown in Fig. 1 and the "empty state" shown in Fig. 4, the center of gravity G1 of the carry cart CC is set to be rearward of the connecting part 29. Specifically, 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 located at the above-mentioned position.

[0023] 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 manner so as to form a convex shape that protrudes forward. The grip shaft portion 3013 extends rearward from the upper end of the curved shaft portion 3012 and extends linearly in the front-to-rear direction.

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

[0025] Specifically, the grip portion 302 is cylindrical. The grip portion 302 is formed using a non-slip material such as rubber. The grip portion 302 is attached to the grip shaft portion 3013 so that the peripheral wall of the grip portion 302 covers the outer circumferential surface of the grip shaft portion 3013. The grip portion 302 is disposed on the central axis line CL. A user of the carry cart CC basically holds 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 grip portion 302. The switch 74 is a momentary operation switch that is operated by the user when running the carry cart CC using the motor 72 as a power source. In this embodiment, the switch 74 is provided on the grip portion 302 so that operation of the switch 74 and holding of the grip portion 302 can be performed simultaneously. The switch 74 is connected to the motor control unit 73.

[0027] The carry cart CC has a single front wheel 32 and a pair of rear wheels 34. As shown in FIG. 3 , the contact point of the front wheel 32 with the road surface 10 is designated "P1," the contact point of one of the pair of rear wheels 34 with the road surface 10 is designated "P2," and the contact point of the other of the pair of rear wheels 34 with the road surface 10 is designated "P3." A triangle with vertices P1, P2, and P3 for the single front wheel 32 and the pair of rear wheels 34 is designated a "basic triangle TB." When determining the contact points P1, P2, and P3, the road surface 10 on which the front wheel 32 and the rear wheels 34 are in contact is a horizontal surface.

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

[0029] 1 and 2, the front wheel 32 is connected to the lower end portion of the handle shaft 301 via a shock absorber 36 provided below the connecting portion 29. More specifically, the lower end portion of the handle shaft 301 is fixed to a 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 an 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 about the central axis line CL.

[0030] The front wheels 32 are driven to rotate about the front axle 33 by a motor 72 serving as a power source, and serve as drive wheels that provide propulsive force for travel to the cargo bed 20. As the motor 72, for example, an electric motor of a type that is disposed inside the front wheels 32 and directly drives the front wheels 32 to rotate, 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 controls the operation of the motor 72. The operation of the motor 72 is controlled as follows: When the switch 74 is not operated, the rotation 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 rotation of the motor 72 is started. At this time, the carry cart CC is in a traveling state.

[0032] 1 to 3, both ends of the front axle 33 protrude outward on both sides in the left-right direction from the front wheels 32. <Rear Wheels 34> The rear wheels 34 are rotatably supported by the rear wheel support parts 24. Specifically, the carry cart CC has a bed frame part 23 that extends rearward from a connection part 29 between the bed 20 and the handle part 30. The rear wheel support parts 24 are fixed to the bed frame part 23. The axles of the rear wheels 34 (hereinafter referred to as rear axles 35) are supported by a part of the rear wheel support part 24 that is lower than the bottom surface 21a of the bed main body part 21.

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

[0034] In this embodiment, the center of gravity G1 of the carry cart CC in the loaded state (the state shown in FIG. 1) is set rearward of the center between the front axle 33 of the front wheels 32 and the rear axle 35 of the rear wheels 34. More specifically, the center of gravity G1 of the carry cart CC in the loaded state is set rearward of the center of gravity G2 of the basic triangle TB. 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 located at the above-mentioned position.

[0035] 6 to 8, the carry cart CC is provided with the shock absorber 36 that absorbs impacts applied to the front wheels 32. The shock absorber 36 is provided between the lower end of the handle portion 30 and the front wheels 32. The shock absorber 36 has a link member 37, an arm 41, a bracket 51, and an elastic portion 55 that serves as a shock absorber.

[0036] <Link member 37> Of the various parts of the shock absorber 36, the link member 37 constitutes the part that is fixed to the lower end portion of the handle shaft 301. As described above, the lower end portion of the handle shaft 301 protrudes downward beyond the lower bearing plate portion 26. The link member 37 is attached to the lower end portion of the handle shaft 301 by a fastening member 38 such as a bolt so as to be rotatable together with the handle shaft 301.

[0037] The link member 37 has a pair of link main bodies 39 that extend vertically and are located rearward of the front axle 33. The pair of link main bodies 39 are spaced apart from each other in the direction in which the front axle 33 extends. The distance between the link main bodies 39 is slightly larger than the dimension of the front wheel 32 in the direction in which the front axle 33 extends.

[0038] <Arm 41> Of the various parts of the shock absorber 36, the arm 41 constitutes the part that is connected to the front wheel 32. The arm 41 includes a pair of arm main bodies 42 and an arm attachment part 46. Each arm main body 42 includes a front plate part 43 and a rear plate part 45 that is adjacent to the rear side of the front plate part 43 and is connected to the front plate part 43 in a bent state. The pair of arm main bodies 42 are disposed on both sides of the front wheel 32 in the extension direction of the front axle 33. When the front wheel 32 and both rear wheels 34 are in contact with a horizontal surface, for example, the general road surface 11, the front plate part 43 is inclined with respect to the general road surface 11 so that it is lower towards the front.

[0039] The arms 41 support the front axles 33, thereby supporting the front wheels 32 on the link members 37. More specifically, each front plate 43 has a notch 44 formed therein that extends diagonally upward and rearward from the front lower end of the front plate 43 when the front wheels 32 and rear wheels 34 are both in contact with the same horizontal plane. That is, the notch 44 of each front plate 43 is inclined with respect to the horizontal and vertical planes so that the more rearward the notch 44 is positioned, the higher it is. The notch 44 of each front plate 43 engages with portions of the front axles 33 that protrude outward on both sides of the front wheels 32 in the left-right direction. Due to this engagement, the front wheels 32 are supported by the arms 41 at both front plate portions 43.

[0040] The arm attachment portion 46 connects the rear edges of the pair of arm main bodies 42 rearward of the front wheels 32. The arm 41 configured as described above is disposed between the pair of link main bodies 39. More specifically, each arm main body 42 is disposed adjacent to the inside of the link main body 39 in the direction in which the front axle 33 extends. Each arm main body 42 is connected by a link shaft 40 to the link main body 39 adjacent to it in the direction in which the front axle 33 extends, rearward of the front wheels 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 includes a bracket main body 52 and a pair of mounting plates 53. The pair of mounting plates 53 are adjacent to the outer sides of the link main body 39 in the direction in which the front axle 33 extends. The bracket main body 52 is located rearward of the pair of link main bodies 39 and rearward of the arm main body 42. The bracket main body 52 connects the rear edges of the pair of mounting plates 53 to each other. Each mounting plate 53 is attached to the adjacent link main body 39 on the inner side in the direction in which the front axle 33 extends by a fastening member 54 such as a bolt. Furthermore, each mounting plate 53 is fastened to the adjacent link main body 39 using the link shaft 40.

[0042] <Elastic portion 55> The elastic portion 55 is configured by a rubber bushing including an elastic main body portion 56, a first attachment portion 57, and a second attachment portion 58. The elastic portion 55 is disposed between the arm main body portion 42 and the bracket main body portion 52.

[0043] The elastic body 56 is made of an elastic rubber material and is elastically deformable, and has a central axis. Specifically, the elastic body 56 is bowl-shaped with an open rear surface. The outer and inner surfaces of the elastic body 56 have substantially hemispherical curved surfaces that bulge forward.

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

[0045] The elastic portion 55 is attached to the bracket main body 52 at the second attachment portion 58 by a fastening member 61 such as a bolt. The elastic portion 55 is attached to the arm attachment portion 46 at the first attachment portion 57 by a fastening member 62 such as a bolt. The elastic main body 56 of the elastic portion 55 configured in this manner is compressed and elastically deformed as the arm 41 rotates upward with the link shaft 40 as a fulcrum.

[0046] As described above, the front wheel 32 is attached to the handle shaft 301 via the shock absorber 36 including the link member 37 and the arm 41. Therefore, when the handle shaft 301 is rotated about the central axis CL in response to the operation of the grip 302, the front wheel 32 turns in response to the rotation. This turning changes the traveling direction of the carry cart CC.

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

[0048] When using the carry cart CC, the user grips the handle 302 and operates the switch 74, which causes the motor control unit 73 to control the operation of the motor 72. At this time, the front wheel 32 is driven to rotate forward and downward by the motor 72. As a result, the front wheel 32 generates a propulsive force for moving the carry cart CC forward. This propulsive force is transmitted to the rear wheels 34 via the arm 41, the link member 37, the handle shaft 301, and the carrier 20. The rear wheels 34 are pulled forward by the transmitted propulsive force and rotate forward and downward in conjunction with the front wheel 32. At this time, the front wheel 32 and the rear wheels 34 roll forward on the general road surface 11. As a result, the carry cart CC moves forward along the general road surface 11.

[0049] 1 , as the carry cart CC travels, the front wheel 32 makes contact (collides) with (collides with) the rear corner 14 of the step 12 from behind. As a result of this contact, a force F acts on the front wheel 32 from the corner 14 of the road surface 10 in an obliquely upward and rearward direction. This force F causes the arm 41 to rotate upward about the link shaft 40 as shown by arrow A1 in FIG. 1 while compressively elastically deforming the elastic portion 55 (see FIG. 8 ) rearward. In this embodiment, the impact caused by the front wheel 32 contacting the step 12 is mitigated by this compressive elastic deformation of the elastic portion 55.

[0050] As shown in Fig. 9 , as the carry cart CC continues to move forward, the front wheel 32 climbs up the step 12. As the front wheel 32 climbs up the step 12, the force F applied to the front wheel 32 from the corner 14 decreases. As the force F decreases, the elastic restoring force of the elastic portion 55 causes the arm 41 to rotate downward about the link shaft 40, as shown by arrow A2 in Fig. 9 . Then, as shown in Fig. 10 , when the front wheel 32 passes the corner 14 and climbs up the step 12, and the force F no longer acts on the front wheel 32, the arm 41 rotates based on the elastic restoring force of the elastic portion 55, returning the front wheel 32 to the same position as before it climbed up the step 12.

[0051] In the carry cart CC, the load C1 is placed on the loading platform 20. Therefore, if the load C1 is placed on the loading platform 20 and the elastic portion 55 of the shock absorber 36 is compressed and elastically deformed, the deformation allowance of the elastic portion 55 is reduced accordingly, which may result in the shock absorber 36 not being able to fully provide its shock absorbing function.

[0052] In this regard, in this embodiment, the center of gravity G1 of the carry cart CC is set rearward of the connection portion 29 between the handle portion 30 and the loading platform 20. Therefore, compared to when the center of gravity G1 of the carry cart CC is set forward of the handle portion 30, the weight of the transported object C1 placed on the loading platform 20 is less likely to be applied to the front wheels 32 and the shock absorber 36. This prevents the weight of the transported object C1 placed on the loading platform 20 from being concentrated on the front wheels 32 and the shock absorber 36, thereby preventing the elastic portion 55 of the shock absorber 36 from being compressed and elastically deformed by the weight of the transported object C1. Therefore, when the carry cart CC travels, a decrease in the deformation allowance due to the compressive elastic deformation of the elastic portion 55 can be suppressed, thereby achieving an appropriate shock-absorbing function by the shock absorber 36.

[0053] <Advantages of this embodiment> The advantages of this embodiment will be described. (1) The carry cart CC includes front wheels 32, rear wheels 34, a platform 20 on which a transported object C1 is placed, and a handle 30 that extends vertically, is connected at its vertically middle portion to the platform 20, and is gripped by a user when walking. The carry cart CC includes a shock absorber 36 that is provided between the lower end portion of the handle 30 and the front wheels 32, has an elastic portion 55 made of an elastic material, and absorbs impacts applied to the front wheels 32 through compressive elastic deformation of the elastic portion 55. The center of gravity G1 of the carry cart CC is set rearward of the connecting portion 29 between the platform 20 and the handle 30.

[0054] According to the above-described configuration, the reduction in the deformation allowance due to the compressive elastic deformation of the elastic portion 55 can be suppressed when the carry cart CC is traveling, and therefore the shock absorber 36 can provide an appropriate shock absorbing function.

[0055] (2) The handle portion 30 includes a handle shaft 301 having a central axis CL extending 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. A bearing portion 25 is provided in the cargo bed 20. The bearing portion 25 supports a middle portion of the handle shaft 301 in the vertical direction so that the handle shaft 301 is rotatable about the central axis CL.

[0056] According to the above-described configuration, the user can steer the carry cart CC by changing the turning angle (steering angle) of the front wheels 32 by rotating the handle portion 30, more specifically the handle shaft 301. According to the above-described configuration, the steerable carry cart CC can obtain an appropriate shock-absorbing function from the shock absorber 36 while traveling.

[0057] (3) The center of gravity G1 of the carry cart CC in the "loaded state" is set rearward of the center between the front axle 33 of the front wheels 32 and the rear axle 35 of the rear wheels 34. With the above configuration, the load acting on the front wheels 32 and the shock absorber 36 can be reduced by placing the transported object C1 on the loading platform 20 compared to when the center of gravity G1 is set in the center between the front axle 33 and the rear axle 35 or when the center of gravity G1 is set forward of the center. Therefore, it is possible to prevent the elastic portion 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 that constitutes the upper end portion of the handle portion 30 and is gripped by a user, and extends in a rearward tilted state so that the upper end portion of the handle portion 30 is located rearward of the lower end portion. The carry cart CC has a single front wheel 32 and a pair of rear wheels 34. When a basic triangle TB is defined as a triangle having vertices P1, P2, and P3 of the front wheel 32 and the rear wheel 34 that contact the road surface 10, the center of gravity G2 of the basic triangle TB and the grip portion 302 overlap in a plan view.

[0059] With the above configuration, when a user applies force from above to the grip portion 302, the load is applied toward the center of gravity G2 of the basic triangle TB. Therefore, the load applied to the handle portion 30 can be balanced by the three wheels, specifically the single front wheel 32 and the pair of rear wheels 34. This allows the handle portion 30 to function as a "walking stick" that supports the user.

[0060] (5) The center of gravity G1 of the carry cart CC in the "loaded state" is set rearward of the center of gravity G2 of the basic triangle TB. With the above configuration, the load on the front wheels 32 and the shock absorber 36 can be reduced by placing the load C1 on the platform 20, compared to when the center of gravity G1 overlaps with the center of gravity G2 of the basic triangle TB in a plan view or when the center of gravity G1 is forward of the center of gravity G2 of the basic triangle TB. Therefore, it is possible to prevent the elastic portion 55 from being compressed and elastically deformed by the weight of the load C1.

[0061] <Modifications> The above embodiment can be modified as follows: The above embodiment and the following modifications can be combined and implemented within the scope of technical compatibility.

[0062] An alternate operation switch may be provided as the switch 74. In this case, the operation of the motor 72 can be controlled, for example, as follows: When the switch 74 is turned on, the motor 72 is rotated, and when the switch 74 is turned off, the motor 72 is stopped.

[0063] The switch 74 may be provided in a location other than the grip portion 302. For example, the switch 74 may be provided on the curved shaft portion 3012 of the handle shaft 301 or on the cargo bed 20.

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

[0065] The gripping portion 302 may be positioned such that the center of gravity G2 of the basic triangle TB and the gripping portion 302 do not overlap in a planar view, for example, by positioning the gripping portion 302 forward of the center of gravity 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 the curved shaft portion 3012 and the 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 is bent rearward (or forward).

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

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

[0069] An elastic body different from that used in the above embodiment may be used as the elastic portion 55. For example, a spring such as a coil spring or a leaf spring may be used as the elastic portion 55. Furthermore, an elastic body other than a spring may be used as the elastic portion 55.

[0070] The number of front wheels 32 may be changed to more than one. The number of rear wheels 34 may be changed to three or more. If the number of front wheels 32 is changed to more than one, the number of rear wheels 34 may be changed to one.

[0071] The front wheels 32 may be driven to rotate by a motor provided outside the front wheels 32. The front wheels 32 may be driven by a power source other than the motor 72. The rear wheels 34 may be drive wheels that are driven to rotate by a power source, and the front wheels 32 may be driven wheels. Furthermore, in addition to the front wheels 32, the rear wheels 34 may be drive wheels that are driven to rotate by a power source.

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

[0073] In cases where the motor for the front wheels 32 is provided outside the front wheels 32 or where the front wheels 32 are not rotationally driven by a motor, the front axles 33 may be separated from the front wheels 32. In this case, bearing holes may be formed in the front end of each arm main body 42 instead of the cutouts 44. The portions of the front axles 33 that protrude from the front wheels 32 to both sides in the direction in which the front axles 33 extend may be inserted into the bearing holes of the respective arm main bodies 42, thereby being supported by the respective arm main bodies 42. In order to insert the portions of the front axles 33 protruding from the front wheels 32 into the bearing holes of the respective arm main bodies 42, the pair of arm main bodies 42 in the arm 41 may be separated.

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

[0075] The carry cart CC may have a structure for detachably attaching a shopping basket. The carry cart CC may also have a hook for hanging a carrier bag, a purse, or other bag.

[0076] The carry cart CC may be provided with a brake mechanism to stop the cart CC from moving. According to this modification, a braking force can be applied to at least one of the front wheels 32 and the rear wheels 34 while the carry cart CC is moving, thereby making the rotational speed variable. The front wheels 32 and the rear wheels 34 can be stopped from rotating to stop the cart CC from moving. The carry cart CC may also be provided with a brake to keep the cart CC stationary when stopped.

[0077] The center of gravity G1 of the carry cart CC in the "loaded state" may be set so that it overlaps with the center of gravity G2 of the basic triangle TB in a plan view. With this configuration, the load caused by placing an object C1 of the same weight as the load capacity on the loading platform 20 can be distributed in a balanced manner to the three wheels (specifically, the single front wheel 32 and the pair of rear wheels 34). Therefore, the weight of the object C1 placed on the loading platform 20 can be prevented from being concentrated on the front wheel 32 and the shock absorber 36, while also preventing the weight from being increased on the rear wheels 34.

[0078] The center of gravity G1 of the carry cart CC in the "loaded state" may be set rearward of the center between the front axle 33 of the front wheels 32 and the rear axle 35 of the rear wheels 34, and forward of the center of gravity G2 of the basic triangle TB. Also, the center of gravity G1 of the carry cart CC in the "loaded state" can be set in the center between the front axle 33 of the front wheels 32 and the rear axle 35 of the rear wheels 34. Alternatively, the center of gravity G1 of the carry cart CC in the "loaded state" may be set forward of the center between the front axle 33 of the front wheels 32 and the rear axle 35 of the rear wheels 34, as long as the center of gravity G1 is set rearward of the connecting portion 29.

Claims

1. A carry cart comprising front wheels, rear wheels, a platform on which an object to be carried is placed, and a handle portion which extends vertically and whose middle portion in the vertical direction is connected to the platform and which is grasped by a user when walking, wherein a shock absorber is provided between the lower end portion of the handle portion and the front wheel, the shock absorber having a shock absorber member made of an elastic material and which absorbs impacts applied to the front wheel through elastic deformation of the shock absorber member, and wherein the center of gravity of the carry cart is set rearward of the connecting portion between the platform and the handle portion.

2. A carry cart as described in claim 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, and the loading platform is provided with a bearing portion, which supports the middle portion of the handle shaft in the vertical direction so that it can rotate around the central axis.

3. A carry cart as described in claim 1 or 2, wherein the center of gravity of the carry cart is set rearward of the center between the axle of the front wheels and the axle of the rear wheels when the object to be transported having the same weight as the load capacity of the carry cart is placed on the loading platform.

4. A carry cart as claimed in any one of claims 1 to 3, wherein the handle portion comprises a grip portion that forms the upper end portion of the handle portion and is gripped by the user, and the upper end portion extends at a rearward tilt so that it is positioned rearward of the lower end portion of the handle portion, the front wheel is single and the rear wheel is one of two rear wheels provided on the carry cart, and when a basic triangle is defined as a triangle with vertices at the points where the front wheel and the two rear wheels contact the road surface, the center of gravity of the basic triangle and the grip portion overlap in a plan view.

5. A carry cart as claimed in any one of claims 1 to 4, wherein the front wheel is a single wheel and the rear wheel is one of two rear wheels provided on the carry cart, and when a triangle with vertices at the points where the front wheel and the two rear wheels contact the road surface is taken as a basic triangle, the centre of gravity of the carry cart when an object to be transported weighing the same as the load capacity of the carry cart is placed on the loading platform is set rearward of the centre of gravity of the basic triangle.

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