JP2005186729A - Driving mechanism of hand cart or the like - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve problems of a conventional hand cart wherein (1) a person is required to ascend steps having heights such as stairs by lifting the hand cart, (2) there is a danger of dropping load from the stairs in respect of safety, (3) sound is generated since wheel parts vigorously rotates to catch the next step when contacting the step parts in the hand cart mounted with two to four wheels with an axle as a center to more easily ride over the steps by rotating the whole of the wheel parts with the axle as the center in the step parts, and (4) the whole of the wheel parts is rotated by comparatively small irregularity on also a flat land. <P>SOLUTION: This hand cart is constituted of a frame part 1 and left and right wheels 5 provided via a unidirectional rotating and driving mechanism for limiting rotating directions of the wheels 5. The frame constitutes wheel mechanism receiving parts for supporting the left and right wheels 5 and a handle 2 for connecting the receiving parts. The wheels 5 are constituted to have radii approximate to the step heights on which the wheels 5 ascend when used and irregular shapes to catch edge parts of the steps without slip when ascending the steps in road surface grounding parts on outer peripheries. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention relates to a drive mechanism for hand carts, carts, and the like for carrying a load, and more particularly to a drive mechanism that can easily get over even on steps such as stairs as well as on flat ground.

The conventional hand cart has a drive mechanism in which circular wheels are provided on the left and right lower ends of the frame via shafts.
Two- to four-wheeled wheels are attached around the wheel axis as the one that exceeds the step, and the entire wheel part rotates around the wheel axis at the step part so that the step can be easily overcome. was there.
JP 10-226337

A conventional hand cart requires a person to lift and lift the hand cart at a high step such as a staircase. Every climb, it took a lot of effort, and there was a problem in terms of safety, such as the risk of dropping luggage from the stairs.
In addition, two to four wheels are mounted around the wheel axis, and the entire wheel section rotates around the wheel axis at the step section, so that the structure can easily overcome the step is configured. It is complicated, and a striking sound is generated when the entire wheel portion rotates vigorously when it comes into contact with the stepped portion to catch the next stepped portion. At the level difference between the train and the platform, it may be caught in the gap between the train and the platform, or one of the wheels may fall. Even on flat ground, the entire wheel portion may rotate with relatively small unevenness, which affects running comfort. There are also many restrictions on the design given by the complicated configuration.
The present invention solves the above disadvantages.

It consists of a frame portion and left and right wheels provided at the lower end of the frame via a one-way rotational drive mechanism that limits the rotational direction of the wheels.
The frame is formed of a shock-resistant metal or synthetic resin, and constitutes a wheel mechanism receiving portion that supports the left and right wheels and a handle that connects the wheel mechanism receiving portion.
The wheel has a radius that approximates the height of the step that rises during use, and has a concave and convex shape that aims to catch the edge of the step without slipping when climbing the step on the outer road surface grounding part Has been.

By gripping the edges and vertical surfaces of the steps such as stairs with the unevenness on the outer periphery of the wheel, it is not necessary to lift the hand cart even at the step portions, and it is possible to ascend in the manner of pulling the hand cart.
By providing a one-way rotation drive mechanism that can lock the wheels, when climbing the stairs, even if you release your hand, the luggage will slide down, and the tow will be pulled by the weight of the hand cart Can be prevented from falling. The one-way rotation drive mechanism can be released, and when you get off the stairs, you can get off with a more comfortable posture that does not require any force compared to when you get off. .
The diameter of the wheel is the minimum when the wheel rises by pulling the step, such as when the wheel touches a step such as a staircase. You can climb stably with power.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
As shown in FIG. 1, the present invention includes a frame (1) and left and right wheels provided at the lower end of the frame via a unidirectional rotational drive mechanism that limits the rotational direction of the wheels. The frame is formed of a material having impact durability such as metal or synthetic resin, has a wheel mechanism support portion (3) extending downward from the left and right of the handle (2), and is positioned at the lower end of the wheel mechanism support portion. It is comprised by the wheel mechanism attachment part (4).
The one-way rotation drive mechanism will be described in an embodiment of a mechanism using a stopper and a gear while using FIG. 2 and FIG. 3 together. The wheel mechanism mounting portion is provided with an axle (5) and a stopper (6). The stopper is in the form of an arm and is pivotally attached to the wheel mechanism mounting portion by a stopper rotating shaft (8), and has a claw (7) at the end and a pedal (9 having an enlarged area at the opposite end. ) Is provided. The claw has a mechanism in which a force that tries to jump out by the elasticity of the spring or the material works.
The wheel (10) has a disc-shaped wheel base (11) with high rigidity at the center, and a gear (12) on the side facing the wheel mechanism mounting portion. A road surface grounding portion (13) is provided on the outer periphery of the wheel base, and the grounding surface has an uneven grip groove (14) for the purpose of capturing a step edge such as a staircase without slipping. The grip groove of the road surface grounding portion is a groove that is horizontal to the edge of the staircase. The material is strong enough to withstand the weight of the main body or the load to be loaded, and a material having a high frictional resistance such as resin is preferable. However, this is not an absolute condition and may be anything that can capture the edge of the stairs. It is preferable that the wheel diameter has a radius equal to or higher than the step height that rises during use, because the edge of the step and the grip groove are well meshed. In the case of this wheel diameter, it is possible to ascend stably with a minimum force, and safety can be kept high by using a one-way rotation drive mechanism.
However, as a result of examining wheel diameters with all sizes of radii, even when the wheel diameter is small, traction can be achieved if friction that does not slip between the ground contact surface with grip grooves and the rising vertical surface is obtained. It is possible for the wheel to move up in the way that the wheel rotates up the step wall surface and reaches the edge of the step by the pulling force of the rising step from above. In this case, it is considered appropriate that the wheel radius is 40% or more of the step height, preferably 50% or more. At the same time, the frame pulled by the tow person through the handlebar and the parts other than the loading part and the wheel are It is necessary to design the wheel diameter or the frame shape so as not to contact the edge of the step.
The wheel is attached to the frame via the axle, and the gear meshes with the stopper claw. The concave / convex shape of the gear is such that the catch of the stopper is released in the forward rotation in the forward direction and the pawl of the stopper is tightly engaged in the reverse rotation in the forward direction. As a result, the wheel can rotate in the forward direction and can proceed in the forward direction. However, it is a drive mechanism that cannot reversely rotate in the traveling direction and does not reversely move.
The present invention has the above basic configuration, and the operation principle will be described with reference to FIG. As shown in a, when a wheel that has traveled on a flat road surface comes into contact with a step, the contact between the step and the wheel becomes a fulcrum. As shown in b, by grasping the edge of the step without slipping the grip groove, the wheel rolls upward with the contact point between the step and the wheel as a fulcrum, and the step rises. As shown in c, when the wheel climbs the step, the grip groove moves away from the contact between the step and the wheel and returns to the state a. In the series of operations that climb the steps, when a force is applied to the reverse direction of rotation in the downward direction, the claw of the stopper meshes with the gear and the reverse rotation of the wheel is locked. The hand cart with the drive mechanism will not fall.
Next, a case where a person operates to climb up and down steps such as stairs will be described with reference to FIG. As shown to a, a person goes up steps, such as stairs, by the above-mentioned principle of operation while pulling with a handle. At this time, the wheel diameter or frame shape should be set so that parts other than the frame and the loading part and wheels do not come into contact with the steps such as the stairs at the angle of the frame with respect to the step horizontal plane that is formed by a natural posture where the person climbs the stairs with the handle Consideration to design is necessary. Next, the case of getting off will be described with reference to FIG. The stopper shown in FIG. 3 can be released to a position where the claw does not engage with the gear with the stopper rotating coaxial as a fulcrum by moving the pedal. As a result, the reverse rotation lock of the wheel is released, and the wheel can be lowered in the manner of reverse movement as in b. Since the wheels can always be lowered while in contact with the stepped surface, the labor can be greatly reduced as compared with the case where the wheels are lowered like a conventional hand cart.
Next, a first embodiment using the mechanism will be described below.
As shown in FIG. 6, it can be assumed that a loading unit corresponding to various loads is used without interfering with the drive mechanism of FIG. 1. In the vicinity of the frame position, the loading unit chassis (15) and the loading unit body (17) are combined from above and below. The loading body is hollow, and this is a loading space. As the wheel mechanism support portion of the frame enters the wheel mechanism support portion insertion groove (16) of the loading portion chassis, as shown in FIG. 7, the wheel mechanism support portion is accommodated inside the loading portion chassis, and only the wheel mechanism attachment portion. Is exposed outside the loading section chassis. The loading mechanism body is also provided with a wheel mechanism attachment portion insertion groove (18), whereby the wheel mechanism attachment portion is exposed to the outside of the loading portion body.
As shown in FIG. 6, the stacking unit body includes a stacking unit lid (20) that opens and closes using the lid coupling unit (19) as a fulcrum. In order to improve the opening / closing stability, it is more preferable to provide an opening / closing auxiliary stay (21) on the loading unit lid.
It is preferable to provide a wheel cover (22) for improving safety when the wheel accidentally contacts a person during traveling. By making the handle extendable, the usability can be further improved.
As shown in FIG. 8, the upright leg (23) is configured on the loading unit lid so that the stacking unit can be placed in an upright state. By holding the horizontal legs (24), the horizontal legs and wheels can be placed in a grounded state.

Next, other examples of the unidirectional rotational drive mechanism will be described below.
FIG. 9 shows an example in which a free wheel (25) often used for a rear wheel of a bicycle is used as a one-way rotation drive mechanism. In the illustrated free wheel, the gear on which the chain is hung is omitted, but the outer peripheral portion to which the gear is attached is fixed to the wheel mechanism mounting portion. An inner wheel bearing (26) receives the wheel axle (27) of the wheel. Thus, a wheel bearing portion that receives the wheel shaft, that is, a drive mechanism that rotates the wheel only in the forward rotation in the forward direction and disables the reverse rotation in the forward direction. Although the left wheel is described in the figure, in the case of the right wheel, the wheel is mounted on the inner side of the frame opposite to the right wheel in FIG. As with the freewheel, there is a one-way clutch as a mechanism that performs the backstop function. The shape is almost the same as this figure.
FIG. 10 shows an example in which a free hub (28) widely used for a rear wheel of a current bicycle is diverted to a one-way rotation drive mechanism. In the illustrated free hub, a hub portion that is not required in the present invention and a portion that is attached to the frame of the bicycle are omitted, and when actually diverted, it is necessary to cut the portion or make a structure that does not get in the way. The part where the spoke is originally hung is fixed to the wheel mechanism mounting part, and the wheel is fixed to the gear part where the chain is hung. As a result, the wheel rotates only in the forward rotation in the forward direction and becomes a drive mechanism that disables reverse rotation in the forward direction. Although the left wheel is described in the figure, in the case of the right wheel, the wheel is mounted on the inner side of the frame opposite to the right wheel in FIG.
The one-way rotation drive mechanism is not limited to the above examples, and may be other commonly used ones.

Exploded perspective view of basic configuration Plan view of unidirectional rotational drive mechanism Front view of unidirectional rotational drive mechanism State diagram of the wheel during travel including steps State diagram for each step up and down Exploded perspective view of an embodiment with a loading section Loading unit assembly side view of the embodiment Side view of the embodiment One-way rotational drive mechanism perspective view using freewheel One-way rotation drive mechanism perspective view using a freehub

Explanation of symbols

1. Frame 2. Handle 3. 3. Wheel mechanism support part 4. Wheel mechanism attachment part Axle 6. Stopper 7. Nails 8. Stopper rotation shaft9. Pedal 10. Wheel 11. Wheel base 12. Gear 13 Road surface grounding unit 14. Grip groove 15. Loading section chassis 16. Wheel mechanism support portion insertion groove 17. Loading body 18. Wheel mechanism attachment portion insertion groove 19. Lid coupling part 20. Loading section lid 21. Opening / closing auxiliary stay 22. Wheel cover 23. Upright leg 24. Horizontal legs 25. Freewheel 26. Wheel bearing 27. Wheel axle 28. Freehub 29. Wheel receiver

Claims (3)

It consists of a frame constituting an arbitrary body, a handle part provided on the frame, and left and right wheels provided near the left and right lower ends of the frame via a rotational drive mechanism. A drive mechanism such as a hand cart, which is provided with unevenness to capture an edge portion of an arbitrary step. The drive mechanism for a hand cart or the like according to claim 1, wherein the rotation drive mechanism can be switched to a one-way rotation drive mechanism that limits a rotation direction to one direction. The radius of the wheel approximates the height of an arbitrary step such as a staircase, and when contacting the step, a part of the unevenness provided on the outer periphery of the wheel contacts the edge of the step. 2. A drive mechanism such as the hand cart described in 2.

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