JPH11314501A - Caster - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ride across a step more easily than a prior art without modifying a vehicle body, and reduce shock transmitting to a deck body by distributing a difference in height of the step into two stages during riding across the step. SOLUTION: Front wheels 10, rear wheels 20 arranged in a spaced relation relative to the front wheels 10, connecting members 40 connecting the front wheels 10 to the rear wheels 20 and support members 50 being connected between the connecting member 40 and a deck body 90 are provided. The support member 50 has one end supporting the deck body 90 and the other end rotatably pivoted to the connecting member at a support point 30. The support point 30 is arranged between a vertical line extending through a rotary shaft 60 of the front wheel and a vertical line extending through a rotary shaft 70 of the rear wheel, and under the rotary shaft 60 of the front wheel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a caster that can easily or hardly climb over a stepped road surface, and further reduces the impact of a carrier body that is received when climbing over a step or going over a step. In particular, the present invention relates to a caster that can be mounted on a vehicle such as a trolley, a wheelchair, and a baby carriage.

[0002]

2. Description of the Related Art Conventionally, as a caster mounted on a vehicle body, as shown in FIG. 7, a wheel 120 rotatably mounted on a support member 150 is provided.
Is mounted on the lower part of the vehicle and the wheel body 120 is moved by rotating the wheels 120 while keeping the height of the body body 190 substantially constant. Normally,
It is known that the carrier body 190 is pushed from behind by human power and travels, or in a wheelchair or the like, the vehicle automatically travels by an electric motor or the like.

[0003]

However, such a caster requires a very strong force to get over the road because the road surface has a step of only a few centimeters. Sometimes it became impossible. In such a case, in order to get over such a step, lift the front of the luggage body with the rear part of the vehicle body fixed and place the front wheel on the step, and then lift the rear wheel to I was going to put on. However, when a step is to be performed by such a method, for example, when a substantial amount of a heavy object is loaded on a truck, very large labor is required. further,
Since a disabled person cannot get out of a wheelchair like a wheelchair, it may not be possible to get over a step without a caregiver.

Further, in the conventional casters, when the load carrier changes over the step, the height of the step when the wheels of the casters cross the wheel is directly transmitted to the body of the load as a change amount, and the impact is considerable. It will be. Therefore, when a fragile article is placed on the bed, the article may be damaged, and in the case of a wheelchair, a very large impact is given to a sitting human body. . In particular, when the vehicle goes down a step, it appears more remarkably, and this impact becomes unbearable.

Therefore, the present invention provides a method for overcoming a step easily by replacing a conventional caster with a caster according to the present invention, without changing the vehicle body itself. An object of the present invention is to provide a caster having a simple structure capable of reducing an impact transmitted to a carrier body by dispersing a change amount corresponding to a height of a step into two stages. On the contrary, the present invention also provides a caster in which it is difficult to get over even a slight step.

[0006]

In order to solve the above-mentioned problems, a means adopted by the invention described in claim 1 of the present invention is that "the front wheel 10 and the front wheel 10 are arranged at a distance from each other. Rear wheel 20, and connecting member 4 for connecting front wheel 10 and rear wheel 20
0, a supporting member 50 connected between the connecting member 40 and the carrier body 90, one end of the supporting member 50 supporting the carrier body 90, and the other end rotating at the connecting member 40 and the support point 30. The supporting point 30 is freely pivoted on the front wheel rotating shaft 60.
A caster 100 ", which is located between the vertical extension line 62 of the rear wheel shaft 70 and the vertical extension line 72 of the rear wheel rotation shaft 70 and below the front wheel rotation shaft 60. That is, the support point 30 is connected to the front wheel rotation shaft 60.
Between the vertical extension line 62 of the front wheel rotation shaft 70 and the vertical extension line 72 of the rear wheel rotation shaft 70 and below the horizontal position of the front wheel rotation shaft 60 so as to be freely rotatable. Thus, the downward force applied to the front wheel 10 can be reduced, while the front wheel can be given a force acting substantially upward, and the impact when the vehicle goes over a step can be reduced.

Further, the means adopted by the invention as defined in claim 2 includes a “front wheel 10, a rear wheel 20 disposed at a distance from the front wheel 10, and a connecting member 40 connecting the front wheel 10 and the rear wheel 20. And a support member 50 connected between the connecting member 40 and the carrier body 90. One end of the support member 50 supports the carrier body 90, and the other end is rotatable about the connecting member 40 and the support point 30. The support point 30 is located between the vertical extension line 62 of the front wheel rotation shaft 60 and the vertical extension line 72 of the rear wheel rotation shaft 70 and below the front wheel rotation shaft 60. The caster 100 "is the gist. That is, by providing the position of the support point 30 above the front wheel rotation shaft 60 of the front wheel 10, a substantially downward force acts on the front wheel 10, so that it is difficult to cross the step. it can.

Further, the means adopted by the invention according to claim 3 is a "caster according to claim 1 or 2, wherein the front wheel 10 comprises a plurality of wheels".

Further, the means adopted by the invention according to claim 4 is a "caster according to claim 1 or 2, wherein the rear wheel 20 comprises a plurality of wheels".

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described with reference to a first embodiment.
The description will be made with reference to the drawings shown in FIGS. The caster 100 according to the present invention includes a front wheel 10 provided forward in the traveling direction, a rear wheel 20 having a shorter diameter than the front wheel 10 provided behind and spaced apart from the front wheel 10, and a rotational axis of each of the front wheel 10 and the rear wheel 20. A connecting member 40 for holding, and a supporting member 5 for supporting the connecting member 40 and the bed body 90
0 is provided.

The front wheel 10 and the rear wheel 20 are rotatably mounted on a connecting member 40 on a front wheel rotation shaft 60 and a rear wheel rotation shaft 70, respectively. The connecting member 40 has a rear wheel supporting member 41 for supporting the rear wheel 20 and a connecting portion main body 42, and the rear wheel supporting member 41 is rotatable about a rear wheel turning support shaft 43 with respect to the connecting portion main body 42. And the direction of the rear wheel 20 can be freely changed through the rear wheel support member 41. At this time, it is desirable that the front end 21 of the rear wheel 20 be located rearward of the rear wheel turning support shaft 43 in order to ensure the running stability of the rear wheel 20.

The support member 50 is pivotally mounted on the connecting member 40 such that its substantially distal end portion is rotatable about the support point 30. The support point 30 is formed by a vertical extension line 62 of the front wheel rotation shaft 60 and a vertical extension line 7 of the rear wheel rotation shaft 70.
2 and the support point 30 is provided below the horizontal position of the front wheel rotation shaft 60. At the opposite end of the support member 50, a pedestal body mounting pedestal 80 for fixing the pallet body 90 is pivotally mounted on a pedestal pivot support shaft 81. The carrier main body 90 arbitrarily selected depending on the application is fixed to the carrier mounting base 80. The attached supporting member 50 is attached to the carrier main body 90 so as to be pivotable on a pedestal pivoting support shaft 81,
The direction of the front wheel 10 can also be freely changed. In addition,
In the present embodiment, the rear wheel support member 41 and the support member 50 are provided so as to be freely rotatable. However, the present invention is not limited to this. Also, as long as the position of the support point 30 is provided between the front wheel rotation shaft 60 and the rear wheel rotation shaft 70 and below the front wheel rotation shaft 60, the position can be freely changed in that range. . Now, a technical idea when the caster 100 thus configured actually crosses a step will be described along with a difference in operation depending on the position of the support point 30 in comparison with a conventional example.

First, a conventional force exerted when a caster rides over a step is as follows, as shown in FIG. 8, when a wheel attached to the body contacts a rim of the step while the body is moving forward. The force acts on the wheel, and this force is broken down into a vertically upward force and a vertically backward force, and the upward force pushes the wheel above the step. Therefore, as shown in FIG. 9, when the height of the step is equal to or higher than the center axis of the wheel, the force acts only rearward and does not work upward, and it is not possible to ride on the step. You can't.

In the caster 100 according to the present invention having the above-described structure, as shown in FIG. 2, first, when the wheel comes into contact with the edge of the step, the front wheel 10 exerts a rearward force due to the step. Become. However,
The carrier main body 90 exerts a forward force because an inertial force acts when the body is moving forward. Therefore, a force is similarly exerted forward at the support point 30 through the support member 50 fixed to the carrier body 90. At this time, if the support point 30 is located at the same height as the front wheel rotating shaft 60 of the front wheel 10, as shown in FIG. 3, the force acting on the support point 30 is the rearward force A from the step. Since the forward force B from the support member 50 is offset, the front wheel 10
No force is exerted in the upward direction, and no effect can be expected for overcoming a step.
This is the same principle as the conventional caster.

On the other hand, according to the present invention, since the support point 30 is located below the height of the front wheel rotating shaft 60 and the support point 30 is provided rotatably,
The force a acting backward on the front wheel rotating shaft 60 and the supporting point 30
Is applied by the connecting member 40 to
The force a acting on the front wheel rotating shaft is substantially upward force c,
The force b acting forward is generated by the force d acting substantially downward. Therefore, the connecting member 40 receives a force in the opposite direction between the front wheel rotating shaft 60 and the support point 30, so that the rotating force acts clockwise as a whole in FIG. As a result, only pushing the carrier body 90 in the forward direction, that is, merely applying a forward force to the casters 100, forces are applied to the front wheel 10 upward, so that the step can be easily overcome. As described above, in the caster 100 of the present invention, it is possible to ride on a step having a height that was conventionally difficult to ride.

Further, the step can be more easily climbed by the synergistic effect with the upward acting force received from the edge of the step when climbing the step according to the conventional example.

Further, the caster 100 of the present invention has the following functions. In the conventional caster shown in FIG. 7, the load of the heavy object placed on the carrier body 90 is supported by one wheel on one caster 100. One wheel will receive all. On the other hand, as shown in FIG. 4, the caster 100 according to the present invention applies the load applied to the support point 30 to the front wheel 10 and the rear wheel 2.
0 can be distributed and paid. That is, the load applied to one of the wheels 60 and 20 can be reduced as compared with the conventional product. Therefore, since the force acting below the front wheel 10 is smaller than that of the conventional type, the level difference can be further easily increased in synergy with the above-described effect as compared with the conventional caster.

At this time, at the support point 30, the support member 5
If the connecting member 40 is fixed to the front wheel 10, the rear wheel 20 also separates from the road surface while the front wheel 10 crosses the step, and eventually receives a load only on the front wheel. Since the connecting member 50 and the connecting member 50 are rotatably provided, the rear wheel 20 can always be in contact with the road surface even if the front wheel 10 moves upward on the way over the step. Therefore, from the time when the front wheel 10 starts climbing the step, the supporting point 30 is always maintained until the front wheel 10 finishes climbing.
Can be distributed between the front wheel 10 and the rear wheel 20,
The force applied to the front wheel 10 can always be reduced.

Next, the behavior of the support point 30 when the caster 100 of the present invention actually crosses a step will be described.

FIG. 10 shows the locus of a conventional caster so that it can be easily compared with a conventional caster.
In this conventional example, the amount of change corresponding to the height of the step is transmitted as the amount of change of the support point 30 from the time when one wheel comes into contact with the step to the time when the wheel is completely lifted. Therefore, the trajectory becomes like X.
In other words, in the conventional caster, the force applied to change the height of the step, that is, all the work must be applied until one of the wheels rides on the wheel, so that a large force is instantaneously applied when going over the step. In short, the impact increases. This is due to the luggage on the bed body 90,
In the case of a wheelchair, it is a direct impact on the human body.

On the other hand, as shown in FIG. 5, the caster 100 having the structure of the present invention
Is located between the front wheel 10 and the rear wheel 20, the amount of change can be reduced by the ratio of the distance between the front wheel rotation shaft 60 and the rear wheel rotation shaft 70 and the support point 30. That is, even when the front wheel 10 has finished climbing the step, the change in the height of the support point 30 is smaller than the amount of change corresponding to the height of the step. The amount of change in the dust is changed when the rear wheel 20 rides.
Therefore, the locus becomes like Y. As a result, the behavior of the support point 30 of the caster 100 of the present invention becomes as shown in FIG. Thus, in the caster 100 of the present invention, since the support point 30 is provided rotatably, the amount of change in the height of the step can be distributed by the front wheel 10 and the rear wheel 20, and By dividing the height into two steps and applying a small force, the step can be overcome. At this time, the carrier body 90 communicating with the support point 30
Therefore, the impact on the carrier body 90 can be reduced, and the load on the carrier can be prevented from being damaged, and the impact on the human body on the wheelchair can be reduced. .

Although the present operation has been described by taking the case of climbing over a step as an example, the amount of change to the cargo bed main body 90 can be dispersed not only when the vehicle goes over the step but also when there is a step. In particular, the impact on the luggage on the luggage carrier and the impact on the human body on the wheelchair is more effective because the greater the impact, the greater the impact.

Next, the second embodiment will be described.
As shown in (2), the caster 100 of the present invention in the second embodiment has the support point 30 located above the horizontal position of the front wheel rotating shaft 60 of the front wheel 10. Other configurations are the same as in the first embodiment. According to this second embodiment,
In contrast to the above-described upward force of the front wheel 10 of the first embodiment, it acts downward. That is, the rear force a ′ acting on the front wheel 10 and the force b ′ acting forward of the support point 30 are respectively reduced by the connecting member 40 so that the force a ′ hitting the front wheel 10 becomes a substantially downward force c ′. The force a 'is the force c' that acts substantially upward.
Will occur. That is, when a force in the opposite direction is applied to the connecting member 40 between the front wheel rotating shaft 60 and the support point 30, the rotating force acts counterclockwise in FIG. 6 as a whole. Therefore, this caster 100
In the above, it is very difficult to get on even if the step is smaller than the radius of the wheel. For example, when a step is provided because it is dangerous if the step exceeds a certain range, the cart using the caster 100 of the present invention is used. By using, it is possible to reduce the number of steps that exceed the step difference by mistake, and also to set the steps provided therefor lower than in the conventional case.

Further, as in the first or second aspect of the present invention, the front wheel 10 and the rear wheel
Does not necessarily have to be a single wheel, and by using a plurality of wheels, more stable traveling can be achieved.

[0025]

As described above, in the caster according to the present invention, the caster according to the present invention can change the front wheel to a force acting upward only by applying a force acting forward to the caster. Further, since the load applied to the support point can be distributed to the front wheel and the rear wheel, the vehicle can easily get over the step with a small force. In addition, since the amount of change in the step when riding on the step can be distributed in two stages, the step can be climbed with even less force, and the impact on the carrier at that time can be further reduced. is there. This allows
While preventing damage to the luggage placed on the bed,
In a wheelchair or the like, it is possible to provide a more comfortable wheelchair with less impact on a human body.

In the caster according to the second aspect, it is possible to make it difficult to get over a step compared to a conventional caster. For example, when a boundary is provided by a step to prevent danger. It can prevent the body from getting over.

Further, in the casters according to the third and fourth aspects, by providing a plurality of front wheels or rear wheels, it is possible to provide a caster having excellent running stability.

[Brief description of the drawings]

FIG. 1 is a side view of a caster according to a first embodiment of the present invention.

FIG. 2 is a side view showing a state where the caster according to the first embodiment of the present invention crosses a step.

FIG. 3 is a side view of another embodiment for comparison with the caster of the present invention.

FIG. 4 is a side view showing a load applied to a caster according to the first embodiment of the present invention.

FIG. 5 is a side view showing a locus when the caster according to the first embodiment of the present invention crosses a step.

FIG. 6 is a side view illustrating a caster according to a second embodiment of the present invention.

FIG. 7 is a side view showing a conventional caster.

FIG. 8 is a side view showing a force applied when a conventional caster crosses a step.

FIG. 9 is a side view showing a force applied when a conventional caster crosses a step.

FIG. 10 is a side view showing a locus when a conventional caster crosses a step.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Front wheel 20 Rear wheel 30 Supporting point 40 Connecting member 50 Supporting member 60 Front wheel rotation axis 70 Rear wheel rotation axis 80 Latch mounting base 90 Luggage body 100 Caster

Claims (4)

[Claims] 1. A front wheel, a rear wheel disposed at a distance from the front wheel, a connecting member connecting the front wheel and the rear wheel, and a supporting member connected between the connecting member and the carrier body. One end of the support member supports the carrier body, and the other end is rotatably mounted on the connection member and a support point, and the support point is a vertical extension of the front wheel rotation shaft and a rear end thereof. A caster located between a vertical extension of a wheel rotation shaft and below the front wheel rotation shaft. 2. A front wheel, a rear wheel disposed at a distance from the front wheel, a connecting member connecting the front wheel and the rear wheel, and a supporting member connected between the connecting member and the carrier body. One end of the support member supports the carrier body, and the other end is rotatably mounted on the connection member and a support point, and the support point is a vertical extension of the front wheel rotation shaft and a rear end thereof. A caster located between a vertical extension line of the wheel rotation shaft and above the front wheel rotation shaft. 3. The caster according to claim 1, wherein the front wheel comprises a plurality of wheels. 4. The caster according to claim 1, wherein the rear wheel comprises a plurality of wheels.