JP3028282U - Wheelchair auxiliary wheels - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] It is possible to easily and safely lift the front wheel 8 of the wheelchair 1 without limitation to get over the step 23, and make the wheelchair 1 difficult to fall backward, and even if it falls. Auxiliary device that attenuates shock. SOLUTION: A movable "support shaft" 13 attached to an axle 6 of a rear wheel 5 of a wheelchair 1, an "auxiliary wheel" 15 attached to a tip of the support shaft 13, a support shaft 13 and a body frame 16 are provided. An auxiliary device for wheelchairs, which is composed of a "spring" 17 that connects with and a "gear" 19 that prevents reverse rotation of the support shaft.
The tower occupant 25 has a center of gravity 26 in the manner of a reclining seat.
To the rear to lift the front wheel 8 and climb over the step 23 while keeping the front wheel 8 floating. When falling, the "spring" 17 collapses and absorbs kinetic energy.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a manual wheelchair, which enables safe and easy overriding of a step using a movable auxiliary wheel, and a part of the device when the wheelchair falls backward. It absorbs kinetic energy when it collapses, and when a fall occurs, auxiliary wheels enter between the seat back and the ground to prevent the human body from touching the ground.

[0002]

[Prior art]

 A conventional manual wheelchair has a small diameter caster wheel for operation on the front wheels and a large diameter wheel for driving on the rear wheels, and the operability on a flat surface is good.

However, since the radius of the front wheel is extremely small, it is almost impossible to get over the step.

As a countermeasure for this, for example, as described in Japanese Utility Model Laid-Open No. 55-67722, there is known a wheelchair equipped with a step-over climbing tool that swings near a small diameter front wheel.

In the wheelchair having the above-mentioned ride-over gear, the lower surface of the ride-over gear is curved, the corner of the step portion comes into contact with the lower surface of the ride-on gear, and the front wheels are further moved forward. It is possible to lift up and overcome bumps. However, such a wheelchair has a complicated structure and increases weight. Also, since the center of the rear axle of the wheelchair is close to the vertical line passing through the center of gravity of the wheelchair, if the front of the wheelchair is lifted too much when riding over a step, the wheelchair may fall backward. .

[0006] Also, a method is known in which the front part of a general wheelchair is lifted by training to climb over a step while maintaining the balance while maintaining the center of gravity, but there is a risk of falling backward during practice. Practice is difficult.

As a countermeasure for these problems, for example, as disclosed in Japanese Utility Model Laid-Open No. 05-74519, a support arm is fixed to a rear frame of a wheelchair, and a tip portion of the support arm is extended to the outside of a rear wheel. There is known a wheelchair capable of climbing over a step while lifting a front wheel by acting as a support tool for maintaining a posture when the wheelchair is tilted backward.

In the wheelchair having the above-described conventional support arm, since the support arm is fixed to the frame of the wheelchair, the height of the step over which the vehicle can climb in advance is limited.

Further, when a strong impact is applied to the wheelchair in the direction of falling the wheelchair backward, the entire wheelchair floats up with the tip of the support arm as a fulcrum, rotates backward, and is struck upright on the ground. There is a nature.

[Problems to be solved by the device]

The present invention has been made in view of the above problems of the prior art. The purpose of the present invention is to lift the front wheel of a wheelchair easily and without restriction without requiring special training. It is an auxiliary device for a safe wheelchair that can be operated and does not have to worry about falling backwards.

Furthermore, when the wheelchair receives a strong impact in the direction of falling the wheelchair backward, part of the device collapses and absorbs the kinetic energy associated with the impact, stopping the human body in a safe state. Device.

[0012]

[Means for Solving the Problems]

 The auxiliary device for a wheelchair according to the present invention comprises a support shaft attached to the axle of the rear wheel of the wheelchair so as to be movable around the axle, an auxiliary wheel attached to the tip of the support shaft, and one end of The device is composed of a spring attached to the vehicle body frame at the other end, and a gear attached to the rear wheel axle to prevent the support shaft from inadvertently starting reverse rotation. The spring is attached in the direction toward the center of the deploying shaft, and the auxiliary wheel is installed at a position where it does not contact the ground on flat ground.

[0013]

[Embodiment of device]

 Embodiments of the invention will be described with reference to the drawings. The wheelchair body 1 of FIG. 1 has a conventionally known structure, has a handgrip 4 at a rear end of a seat portion 2, and is equipped with a pair of left and right large rear wheels 5 and a small front wheel 8. With such a configuration, a footrest 10 for placing a foot is provided in front of the left and right front legs 9 to which the front wheels 8 are attached, and an operation ring 7 for driving rear wheels is provided outside the rear wheels 5. Further, the footrest mounting pipe 11, the front leg 9 and the lower end of the handgrip 4 are connected to each other by a lower pipe 12 on both sides.

In the embodiment of FIG. 2, the auxiliary wheel support shaft 13 is attached to the axle 6 of the rear wheel 5, and the auxiliary wheel 15 is attached to the tip of the auxiliary wheel support shaft 13. A support shaft 16 provided at the rear portion of the lower pipe 12 and a support shaft are connected by a spring 17. The axle 6 of the rear wheel 5 is provided with a gear 19 that prevents the auxiliary wheel support shaft 13 from accidentally rotating in the reverse direction.

FIG. 3 shows a situation when climbing over a step. Immediately before the step 23, the occupant 25 shifts the center of gravity 26 of the body rearward and turns the operation ring 7 for driving the wheelchair 1 in the traveling direction, whereby the propulsive force 27 of the rear wheel 5 and the center of gravity 26 of the wheelchair 1 are moved. By the action of the momentum due to the inertial force 28 which acts on the wheelchair 1, the wheelchair 1 rotates in the direction in which the front wheel 8 floats as shown in the figure.

At this time, the auxiliary wheel 15 first comes into contact with the ground, and then the auxiliary wheel support shaft 13 and the support bearing 16 open around the rear wheel axle 6. However, since the vane 17 is mounted between the support shaft 13 and the support bearing 16, the wheelchair 1 rotates in the direction in which the front wheel 8 floats up and stops in accordance with the magnitude of the force. Further, the force of rotating the wheelchair backward due to the displacement of the center of gravity 26 and the tension of the spring 17 are balanced, so that the wheelchair 1 can maintain the posture in which the front wheel 8 is levitated.

When the rear wheel 5 is rotated in the traveling direction by the operation ring 7 in this posture, the small-diameter front wheel 8 advances on the upper part of the step upper surface 24 without hitting the step 23, and the large-diameter rear wheel 8 Even if 5 abuts on the step 23, it is possible to easily get over the step 23 by simply rotating the rear wheel 5 while moving the center of gravity of the body forward. After overcoming the step 23, the lever 21 is lowered to remove the pawl 20 from the gear 19, and the auxiliary wheel 15 is returned to its original position.

FIG. 4 shows a situation in which the wheelchair has fallen backward. At that time, three cases are assumed depending on the magnitude of the force 29 in the direction in which the wheelchair 1 is turned backward. First, when the force 29 that causes the wheelchair 1 to fall backward is relatively weak, the wheelchair 1 attempts to rotate, but the force 29 is attenuated because of the spring 17. After the force 29 weakens, the elasticity of the spring 17 causes the wheelchair 1 to start reverse rotation. However, since the axle 6 of the rear wheel 5 is provided with the gear 19 for preventing the support shaft 13 from rotating in the reverse direction, the elasticity of the spring does not act and the wheelchair 1 stops.

Next, when the force 29 that causes the wheelchair 1 to fall backward is a strong impact exceeding the elastic limit of the spring 17, the spring collapses 18 and absorbs the kinetic energy of the force 29. In this case the spring collapses irreversibly 18 so that there is no danger of the wheelchair 1 starting to rotate in reverse.

Even if the spring 17 collapses, if the impact of the force 29 is too large to absorb the kinetic energy, the wheelchair 1 falls backward, but at that time, the kinetic energy is the spring 17 first. The force 29 is weakened because it has already been damped in two steps by the elasticity of and the collapse 18. Further, since the auxiliary wheel 15 is sandwiched between the backrest 3 of the wheelchair 1 and the ground surface 22, the tower passenger 25 is prevented from touching the ground.

Even if the device falls over backward and a part of the device collapses, the original effect can be restored by replacing only the collapsed part of the spring 18, which is economical.

FIG. 5 is an enlarged view of a main part. Since the spring 17 is attached toward the center in a direction parallel to the deployment axis centered on the rear wheel axle 6, the expansion rate of the spring 17 increases as the inclination angle of the vehicle body of the wheelchair 1 increases. Is greatly required. Therefore, the leaner the vehicle body, the more difficult it becomes to lean.

Since the auxiliary wheel 15 is provided at a position not contacting the ground surface 22 on a flat ground, it does not hinder the operation of the wheelchair 1 on a flat ground.

Although the present invention has been described above with reference to the embodiments, the present invention is not limited to the above-mentioned embodiments and can be carried out in any manner as long as the scope of claims for utility model is not changed. . For example, as shown in FIG. 6, neither the auxiliary wheel 15 nor the reverse rotation preventing gear 19 is provided, and only the support shaft 14 and the spring 17 extended to the outside of the rear wheel can be attached to maintain the inclination of the vehicle body.

The wheelchair according to the present invention can be driven not only by a manual wheelchair but also by an electric wheelchair, which contributes to downsizing and weight saving of a wheelchair with a step overriding device. Furthermore, the present invention can be used in both folding and fixed (non-folding) wheelchairs.

[0026]

[Effect of device]

 As described above, according to the present invention, regardless of the height of the step 23, the front wheel 8 of the wheelchair can be safely and easily lifted by itself to get over the step 23, and further, the wheelchair 1 may fall backward. There is no accident, and a major accident will not occur even if it should fall. It also has a high practical effect as a safety device to prevent backward fall during balance training.

[Brief description of drawings]

FIG. 1 is an overall side view showing an example of a conventional wheelchair.

FIG. 2 is an overall perspective view showing an embodiment of the present invention.

FIG. 3 is a perspective view when a posture of climbing over a step is taken.

FIG. 4 is a perspective view of the vehicle when it has fallen backward.

FIG. 5 is an enlarged side view of a main part.

FIG. 6 is an overall perspective view showing another embodiment of the present invention.

[Explanation of symbols]

1 Wheelchair body 11 Footrest mounting pipe 2 Seat 12 Lower pipe 3 Seat back 13 Auxiliary wheel support shaft 4 Handgrip 14 Extended support shaft 5 Rear wheel 15 Auxiliary wheel 6 Rear wheel axle 16 Support bearing 7 Rear wheel drive Operation ring 17 Spring 8 Front wheel 18 Collapsed spring 9 Front leg 19 Reverse rotation prevention gear 10 Footrest 20 Claw 21 Claw release lever 22 Ground surface 23 Step 24 Upper surface of step 25 Tower passenger 26 Center of gravity 27 Rear wheel propulsive force 28 Inertial force 29 Force to fall the wheelchair backward

Claims (1)

[Scope of utility model registration request] 1. In a manual wheelchair, a movable support shaft is attached to an axle of a rear wheel of the wheelchair, an auxiliary wheel is attached to a tip end portion of the support shaft, and the support shaft and a vehicle body of the wheelchair are connected by a spring. An auxiliary device for a wheelchair characterized in that a rear wheel axle is provided with a gear for preventing reverse rotation.