JPH11180309A - Hand push cart capable of going up and down stairs - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hand-push type four-wheel cart of such a structure that the rear wheels are folding, wherein inclination of the cart body is precluded through utilization of the rear wheels as buffer when the cart goes up and down stairs, impact to wheel is relieved, the labor in the elevating/descending operations is reduced, and it is made practicable to run both on a flat area and stairs. SOLUTION: The leg of each rear wheel 2 is formed in folding type, and if the leg 4 is folded upward ahead when it 4 is mounted on the rear part of the body by a joint 5 and the cart goes up and down stairs, the rear wheel 2 can make vertical motion with the joint 5 as fulcrum at a point over aslant in the rear of the front wheels 1, and a spring 8 is interposed between a spring receptacle 9 attached to the leg 4 and the bottom of the cart body. Accordingly the rear wheel functions to make one cushion with respect to each level difference of the stairs so as to facilitate the elevating/descending operation. Depending upon the inclination of the stairs, a longer steering rod 11 is installed in a high position in the rear of the body and also a grip 12 in a low position in the front of the body in such a way as double levelled from each other, and thereby it is made easy to hold the body.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wheelbarrow whose rear wheels are of a foldable type so that stairs can be easily moved up and down.

[0002]

2. Description of the Related Art Conventionally, it has been extremely difficult to climb up and down stairs with a four-wheeled wheelbarrow because the vehicle body is inclined, the wheels are impacted by the stairs, and it is difficult to hold.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a hand truck capable of moving up and down stairs, which prevents the body from leaning due to the stairs, reduces the impact of wheels, and facilitates lifting.

[0004]

Means for Solving the Problems (a) The legs of the rear wheel 2 for traveling on flat ground are of a foldable type. The legs are bent when going up and down stairs, and from the rear without legs when going up. When climbing backwards and descending, advance forward from the front with legs and descend. The leg 4 of the rear wheel 2 is attached to the rear of the vehicle body by the joint 5 and is bent forward and upward when moving up and down the stairs.
The fulcrum can be pivoted up and down in a pendulum manner.
A spring 8 is interposed between a spring receiver 9 mounted on the vehicle body and the bottom of the vehicle body to be used as a shock absorbing wheel. (B) According to the steps of the stairs, the small-diameter rear wheels 3 for the stairs are mounted on the front wheels 1 at a high position at the rear of the vehicle body with respect to the front wheels 1. (C) According to the steps of the stairs, a longer rudder rod 11 is mounted at a high position at the rear of the vehicle body, and a handle 12 is mounted at a low position at the front of the vehicle body.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A wheelbarrow having four wheels having a diameter of about 18 cm will be described as an example. (A) The rear wheel 2 for traveling on flat ground has a foldable leg. The left and right legs 4 of the rear wheel 2 are connected at the middle left and right by a spring receiver 9 and a lower end by a rear wheel shaft 10, and the upper ends of the legs 4 are attached to both sides of the rear of the vehicle body by the joints 5, and when climbing stairs, When the leg 4 is bent upward and forward, the pendulum can swing vertically with the joint 5 as a fulcrum. The folded rear wheel 2 approaches the front wheel 1 and the spring bearing 9 is attached to the lower part of the vehicle body at a point where the diameter of the wheel overlaps about 20% as shown in FIG. The spring 8 is attached so that the spring 8 is compressed and the rear wheel 2 is raised by several centimeters when a load is applied. In the rear wheel 2, the width of both the left and right wheels is appropriately widened so that the front wheel 1 and the part overlap, so that they do not come into contact with each other.
Further, a lock 6 is attached to the right leg 4 so that the leg 4 can be fixed in an upright position when traveling on flat ground. Note that the lock 6 has the same mechanism as the lock for the bicycle stand, and is tilted rearward to release the lock by tilting it forward. At the time of release, the locking spring 7 causes the rear wheel 2 to automatically jump upward and forward. . By doing so, the rear wheel 2 can be converted into a rear wheel and a shock absorbing wheel by one-touch one-foot operation according to traveling on flat ground and ascending and descending stairs, so that there is no need to change a person or a load, which is convenient. In addition, the rear wheel 2 is positioned obliquely behind and close to the front wheel 1 to prevent leaning of the vehicle body, and also to provide one cushion against a drop of the stairs, thereby facilitating the lifting to the stairs and further cushioning. In combination with the repulsive action of the spring 8, the impact caused by the steps is absorbed and reduced. (B) According to the steps of the stairs, the small-diameter rear wheels 3 for the stairs are mounted on the front wheels 1 at a high position at the rear of the vehicle body with respect to the front wheels 1. By doing so, the level of the vehicle body is maintained. Note that, for a lightweight object such as a stroller, the stairs rear wheel 3 does not necessarily need to rotate, and therefore may be replaced with a rounded protrusion using an elastic member such as rubber. (C) At a high position at the rear of the vehicle body, a long rudder rod 11 is attached diagonally along the slope of the stairs. (D) A long rudder rod 11 is mounted diagonally along the slope of the stairs at a high position at the rear of the vehicle body in accordance with the steps of the stairs, for a wheelbarrow for nursing care and transporting heavy objects. The handle 12 is mounted at a low position in the front part according to the steps of the stairs. In this way, the longer rudder rod 11 acts as a lever, which makes the lift lighter and makes it easier to hold by step mounting.

The present invention has the above-described structure. When using the above structure, one person usually holds the rudder rod 11 and operates it. Operate two people, one person at a high position on the stairs, one rudder bar
The other one has a handle 1 facing down the stairs
Have two. (A) When traveling on flat ground, the rear wheel 2 runs as a rear wheel with the leg 4 upright and the lock 6 tilted backward and fixed. (B) When climbing the stairs, hold the rudder rod 11 of the wheelbarrow to support the vehicle body, release the lock 6 of the rear wheel 2 forward with the right foot, release it, flip the rear wheel 2 forward and upward, and face the stairs. Ascend while moving backward, pull up from the rear wheel 3 for stairs, then pull up the rear wheel 2 and pull up the front wheel 1. (C) When descending the stairs, the rear wheel 2 is held in a state in which the rear wheel 2 is flipped upward and forward with the rudder rod 11, moves forward from the top of the stairs to the bottom, and the front wheel 1 is the rear wheel 2 and the rear wheel 3 for the stairs. Lower in order. (D) Scope of use The present invention has a wide range of uses, such as nursing wheelbarrows, strollers, shopping carts, carts and stretchers.

[Brief description of the drawings]

FIG. 1 is a side view of a stair climbing state.

FIG. 2 is a side view of a flat-land running state.

FIG. 3 is a front view of a stair climbing state.

[Explanation of symbols]

1 front wheel 2 rear wheel 3 stairs rear wheel 4 legs 5 joint 6 lock 7 lock spring 8 spring 9 spring receiver 10 rear wheel axle 11 rudder rod 12 handle

Claims (2)

[Claims] (1) In a four-wheeled wheelbarrow, when the legs of the rear wheel (2) are foldable and the legs (4) are attached to the rear of the vehicle body by joints (5) and bent forward and upward when going up and down stairs, The rear wheel (2) is swingable up and down in a pendulum manner with a joint (5) as a fulcrum at a point obliquely above and behind the front wheel (1), and is mounted on a leg (4) of the rear wheel (2). A spring (8) is interposed between (9) and the bottom of the vehicle body to be used as a shock absorbing wheel. (B) In accordance with the steps of the stairs, the small-diameter rear wheels for stairs (3) are mounted stepwise at a position higher than the front wheels (1) at the rear of the vehicle body. A wheelbarrow characterized by the above. 2. A steering wheel (12) at a high position at the rear of the vehicle body and a step at a low position at the front of the vehicle (12) in accordance with the steps of the stairs.
The wheelbarrow according to claim 1, further comprising: