JPS6365531B2 - - Google Patents

Description

[Detailed Description of the Invention] This invention was made with the hope that people with spinal cord injuries, especially those with severe spinal cord injuries, would be able to freely drive a wheelchair by making good use of their remaining functions. The front wheels of the wheelchair are used as wheels, the rear wheels are used as casters, and the crank 2 attached to the front wheels is driven in a reciprocating motion, and at the same time, the front wheels also have the function of a back-up stop that prevents the front wheels from rotating in the opposite direction with respect to the direction of travel of the wheelchair. The invention relates to a wheelchair that makes it easier to climb uphills and gradients that limit the expansion of the radius of movement. Published Patent Publication 1985-11852
The ``wheelchair that can be driven without grip strength'' connects a crank attached to the front of the wheelchair with a chain wheel on the rear wheels, and converts the reciprocating motion of the crank into rotational motion of the rear wheels. This invention is a sister invention.

To explain a little more about people with severe spinal cord injuries, the spinal cord becomes damaged due to a fracture or dislodgement of the pelvic bone and loses its function. As a result, paralysis occurs below the level of the damaged spinal cord, and all autonomic nervous functions, including movement, sensation, urination and defecation, sweating, are impaired. As for residual function, only insufficient movement of the shoulder joint, elbow joint, and wrist joint is observed in cases of large and low cases. In other words, the upper arm and forearm move, albeit insufficiently, but the five fingers do not move, so the grip strength is not weak. This residual function is very important,
Through training, small improvements in the tools used, and various innovations, it is possible to expand the scope of daily life that one can perform independently. This wheelchair is one of them.

When a person with severe spinal cord injury rolls a wheelchair, they lack the grip strength, so they attach materials with a high coefficient of friction to the hand rims, create irregularities, or attach protrusions to hold the hand rims in place with the palms of their hands. As a result, I am able to move my wheelchair freely indoors. However, it is no exaggeration to say that there was no definitive method, as the propulsion force was small because muscular strength was distributed in many directions and there was slippage. Outdoors, it is impossible to climb even the slightest incline at the entrance or the slightest incline between buildings.
Even if you get halfway up, you don't have the strength to climb all the way up, and the arm holding down the hand rim gets tired and eventually gives out. If the caster turns in the opposite direction to the direction of the wheelchair's progress while climbing, the physical strength needed to return it to its original position and climb back up is exhausted and no longer exists. You might think that it would be a good idea to apply the brakes and take a break halfway up the slope, but this method is difficult and dangerous because the moment the brakes are released, the wheelchair will start to roll back.
Currently, their radius of movement is small and they live within a very limited and narrow area. Additionally, electric wheelchairs are heavy because they use batteries, and require constant maintenance and charging. Above all, because the remaining functions are not used, there is a risk of the remaining functions becoming stiff and degenerate, and it is not good for the body because it does not provide exercise. Therefore, orthopedic surgeons and physical therapists do not recommend the use of electric wheelchairs.

Therefore, the present invention has been made to solve the above problems, and the drawings are examples.
The configuration of the present invention will be explained according to the drawings.

FIG. 1 is a front view of the invention. A normal wheelchair has casters on the front wheels and large wheels on the rear wheels, but this wheelchair has wheels on the front wheels and casters on the rear wheels, and a crank 2 with a pedal 1 for driving is attached to the front wheel. ing. The brake 3 is used to steer the wheelchair and stop the wheelchair in a fixed position, and the change lever 4 is used to switch the front wheels between forward, neutral, and reverse positions. The reason why the front wheel is smaller and the crank 2 is longer than a normal wheelchair is to physically increase the muscle strength of the upper arm of a person with spinal cord injury and add it to the front wheel to obtain a large propulsion force. be.

FIG. 3 is a longitudinal sectional view and a left side view of the left wheel hub section taken along line A-A' in FIG. 1. The hub shaft 5 is supported by a hub bearing 7 incorporating a bearing 6 and a hub bearing plate 8. The hub bearing 7 is fastened with screws to a plate fixed to the frame of the wheelchair, and retaining rings are fixed on both sides to the end of the hub axle 5, which is bored out to prevent the hub axle 5 from slipping out of the hub bearing 7. Take the bearing supporter out of the hub bearing 7 and secure it with a retaining ring. The changer consists of a sliding wheel 9, a spur gear 10, a bolt 11, a sliding bush 12, and a pin 13.
It consists of five points, and these five points are hereinafter referred to as Chenjia. sliding wheel 9
Insert the part that is smaller than the root circle of the spur gear 10 that lightly slides on the hub axle 5 into the
Fix it with parallel pins to make it one piece. A bolt 11 is inserted into this sliding wheel 9, passed through a chiseled hole cut into the hub shaft 5, and screwed into a sliding bush 12 which slides inside the bored hub shaft 5. A pin 13 implanted in the side surface of the sliding wheel 9 is easily fitted into the side surface supported by the bearing 6 of the wheel hub 14 on the outside of the wheelchair. A spoke hole 15 is made in the brim of the wheel hub 14. A groove is cut in the change lever receiving plate 8 for a ball bearing 16 that supports the end of the wheel hub 14 on the wheelchair frame side, and the gear shaft 18 of the spur gear 17 that is internally meshed with the wheel hub 14 and is idling. Drill a hole and insert gear shaft 1
8, fix it with a retaining ring, and then tighten the gear shaft 18.
Stretch it out and drive it into the hole drilled in the gear shaft fixing plate 19 to fix it. Only the gear shaft 18 that gets in the way of the crank 2 that reciprocates in a circular arc is cut off at the point where it is stopped by a retaining ring. A fixing ring 20 is driven and fixed to the tip of the gear shaft 18 into which the spur gear 17 is fitted, thereby ensuring the fixation of the gear shaft 18. Spur gear 1
7 meshes with the sliding spur gear 10.

A housing 22 incorporating a one-way clutch 21 that engages the hub axle 5 when the wheelchair advances counterclockwise is fitted into the hub axle 5 and fixed with a retaining ring. A crank 2 is fixed to the housing 22, to which a pedal 1 for driving is attached so as to be freely rotatable. Crank stopper 2 serves as the starting point or ending point of the reciprocating movement of crank 2.
Fix 3 to the wheelchair frame. Although FIG. 1 uses a weak tension coil spring 24 to return the crank 2 to its original position, a compression spring or a leaf spring, etc., which springs back when the crank 2 is fully extended, may be used. The gear shaft fixing plate 19 is threaded and fastened together with the plate fixed to the frame of the wheelchair with bolts. A hole is made in the center of the gear shaft fixing plate 19 for the housing 22 to pass through,
By cutting a U-shaped hole in the fixed plate and loosening the screws and bolts of the hub bearing 7, the front wheel and crank 2 can be removed, making assembly and maintenance easy. A compression coil spring 26 is slightly compressed and inserted between the wire holder 25 fixed on both sides with retaining rings in the hub axle 5 and the sliding bush 12. The sliding bush 12, the thrust ball bearing 27 at the head of the wire holder 25,
The wire cap 28 is inserted in this order, the cable wire 29 for sliding the sliding bush 12 is passed through the compression coil spring 26 between the sliding bush 12 and the wire holder 25, and the wire is taken out inside the wheelchair. The cable is stopped by a wire holder 25.
By doing so, the cable wire 29 will not twist even if the hub axle 5 rotates.

FIG. 2 is a front view and a left partial side view of the change lever section. The cable wire 29 is passed through a wire holder 30 fixed to the frame of the wheelchair, and the wire is fixed to a joint plate 31. Joint plate 31 and change lever 4
are connected by a tension coil spring 32. The elasticity of the tension coil spring 32 must be greater than the elasticity of the compression coil spring 26. The change lever 4 is supported by a lever shaft 33 screwed to a plate fixed to the frame of the wheelchair, and guided by a change plate 34 fixed to the frame of the wheelchair. When the change lever 4 is in position D, it is forward drive, when it is in position N, it is neutral, and when it is in position B, it is back drive. At the end of the configuration description, the drive on the right must be made symmetrically to the left. In addition, the brake 3 employs a system in which the brake is applied by pressing the brake lever with the palm of the hand. The one-way clutch 2 is a one-way clutch 21 with a needle bearing,
The one-way clutch 21 will also be abbreviated below.

This wheelchair is designed to be able to drive and operate levers using the pushing muscles of the upper arm, including forward drive, forward back stop, forward overrunning, neutral, back drive,
It has backstop and overrunning functions. I will explain them one by one.

FIG. 4 is a front view of the driving operation. In the left image, the back of the hand is facing downward, and in the right image, the back of the hand is facing upward. People who can drive the wheelchair on the right side of the figure have many remaining functions and are the most suitable method for driving this wheelchair, but the person on the left side of the figure can also be used satisfactorily. Place pedal 1 in the palm of your hand and use your upper arm strength to push crank 2. When the change lever 4 is in position D in FIG. 2, the one-way clutch 21 is locked and rotates the hub axle 5 counterclockwise in FIG. 3. The rotation of the hub shaft 5 is transmitted to the wheel hub 14 through the changer, and the wheelchair moves forward. At this time, the spur gear 17 meshing with the wheel hub 14 is spinning counterclockwise.
Next, when the muscle force applied to the pedal 1 is relaxed, the crank 2 is pulled clockwise by the tension coil spring 24, and the one-way clutch 21 is unlocked and rotated clockwise to the crank stopper 23. It is limited to and stops. At this instant, the wheel hub 14 and hub shaft 5 are rotating counterclockwise, and the wheelchair is moving. If you repeat this action, the wheelchair will run, and if you make the action faster, it will run faster.

Backstop means that the front wheels no longer rotate in the opposite direction relative to the direction the wheelchair is moving, and if even the slightest force is applied to the wheelchair to back it up, the wheelchair will stop exactly in that position. When the palm of the hand is released from the pedal 1 on an uphill slope, clockwise rotation is transmitted from the wheel hub 14 to the hub axle 5 via the changer. At that moment, the one-way clutch 21 locks and attempts to rotate the crank 2 clockwise, but the crank 2 is restricted by the crank stopper 23 and cannot rotate. This transmission occurs instantaneously, so the casters stay exactly in place, facing the direction the wheelchair is traveling, and do not slide off even without applying the brakes.

Overrunning occurs when you are running downhill or accelerating. The steering of this wheelchair is such that when you want to make a big turn, you drive on one side opposite to the direction you want to turn, and when you want to make a small turn, you apply the brakes on the side you want to turn and drive the other side, so you can turn at right angles, and you can also make U-turns. do. When going downhill, you can steer the vehicle while consciously adjusting the force applied to the left and right brakes 3. In contrast to the forward drive, counterclockwise rotation is transmitted from the wheel hub 14 to the hub shaft 5 via the changer, so the one-way clutch 21 is unlocked and the wheelchair runs while the crank 2 remains stopped.

Next, let's talk about neutrals. In FIG. 2, when the change lever 4 is pushed into the N position with the palm of the hand, the tension coil spring 32 pulls the cable wire 29. In FIG. 3, the sliding bush 12 is slid while compressing the compression coil spring 26, and the pin 13 comes out of the hole in the wheel hub 14, and the spur gear 10 is not yet engaged with the spur gear 17. , the wheel hub 14 is free to rotate with respect to the hub shaft 5. Even when crank 2 is activated, the wheelchair spins freely, and when someone else pushes the wheelchair, it moves freely back and forth.

In FIG. 2, when the change lever 4 is inserted into position B, it becomes a back drive. In FIG. 3, the cable wire 29 slides the sliding bush 12 while compressing the compression coil spring 26, and the spur gear 10 meshes with the spur gear 17. When the counterclockwise rotation of the hub shaft 5 is transmitted to the spur gear 17 through the changer, it changes to clockwise rotation, and the wheel hub 14 also rotates clockwise, causing the wheelchair to back up.

The backstop of a back drive means that when the wheelchair is backing up, if even the slightest force is applied to move the wheelchair forward, the wheelchair will stop at that position. When the counterclockwise rotation of the wheel hub 14 is transmitted to the hub axle 5 through the changer, it changes to clockwise rotation, and the one-way clutch 21 is locked and attempts to rotate the crank 2 clockwise. It is restricted by the crank stopper 23 and cannot be rotated.

Overrunning of the back drive means that when the wheelchair is backing up due to acceleration, the crank 2 remains stationary. wheel hub 14
The clockwise rotation of the hub axle 5 passes through the changer.
When the transmission is transmitted to , the rotation changes to a counterclockwise direction, and the one-way clutch 21 is unlocked.

The backstop mechanism works when this wheelchair is moving forward, so the grounding point of the casters is always on the outside of the wheelchair frame, making it highly stable and free of the risk of tipping over. Backward movement is when the wheelchair cannot turn around, and can be limited to indoor narrow spaces, such as when using an elevator or lying next to a bed. If it's indoors, it's flat, so there's no need to worry about falling. However, when this wheelchair backs up, the grounding points of the casters come inside the wheelchair frame, so we cannot be certain that there is no possibility of it falling backwards.
Since this wheelchair will be used by a person with spinal cord injury, stability is a top priority. FIGS. 5 and 6 show a method for preventing backward overturning, and arrows indicate the direction of movement. FIG. 5 shows a wheel mounted at the front of the caster in the direction of travel, slightly higher than the grounding point of the caster. The advantage is that if there is a step when you are moving forward, these wheels will first get over half of it and then use the casters to get over the remaining half. It can ground you and prevent you from falling. Figure 6 shows a supporter attached to the frame of the wheelchair along the casters while the wheelchair is moving forward, slightly higher than the grounding point of the casters. If you are about to fall when backing up, this support will ground you and prevent you from falling.

The feature of this invention is that the wheelchair is driven by making good use of the remaining functions of a person with spinal cord injury, physically increasing the muscle strength in the upper arm and applying it to the front wheels to obtain a large propulsion force and expand the radius of movement. It is in. The effects will be explained below.

If a physically disabled person's remaining functions are not constantly used and trained under the guidance of a physical therapist, they will stiffen and degenerate. In this respect, unlike electric wheelchairs, this wheelchair is driven using residual functions, so the remaining functions are constantly being trained and strengthened, and there is no risk of the remaining functions becoming stiff or deteriorating. Also, using your remaining functions means exercising, which improves the functions of your digestive, respiratory, and circulatory systems, which is good for your body.

Reduction of transmission force due to friction and tension coil spring 24
Without considering the elasticity of the upper arm, this driving method can convert all of the muscle strength of the upper arm into rotational force. This would not be possible with the conventional way of moving a wheelchair for people with spinal cord injuries; by making the front wheel smaller and crank 2 longer, it is possible to physically increase the muscle strength of the upper arm and apply it to the front wheel. This allows the wheelchair to provide a large amount of propulsion.

If the uphill slope is long or the slope is too large to climb all at once, the backstop mechanism will work instantly even when you take your palm off pedal 1, so the casters will point in the direction the wheelchair is traveling without applying the brakes. It stopped exactly in that position,
The wheelchair doesn't slide off. This is safe because it does not require instantaneous braking during the uphill climb, and it is very easy to start, and even if you get tired of driving, you can continue climbing while taking many breaks in the middle of the uphill slope. I can do it. Your climbing ability will increase dramatically.

Being able to drive backwards means being able to turn in a tighter radius. To steer this wheelchair, use the brake 3 on the side you want to turn as a half brake, and drive the opposite side to turn at right angles or make a U-turn. If you are in a narrow space where you cannot turn using the above method, you can drive the wheelchair backwards on the side you want to turn, and forwards on the opposite side, and the wheelchair will spin like a top. Back drive can be used in narrow places where the above cannot be done, such as when going up and down an elevator or when laying next to a bed.

Of course, it can be folded, and when you have someone else push your wheelchair, you can use the neutral mode, which allows the front wheels to rotate freely and the wheelchair to move freely back and forth. This wheelchair is driven by the pedals 1 and does not require hand rims, so it is smaller than a normal wheelchair, and the rear wheels are casters, so the large wheels do not protrude rearward like a normal wheelchair. Overall, it is more compact than a regular wheelchair.

[Brief explanation of drawings]

Fig. 1 is a front view of the present invention, Fig. 2 is a front view and left partial side view of the left change lever part, and Fig. 3 is a longitudinal section of the left wheel hub part taken along line A-A' in Fig. 1. FIG. 4 is a front view of the drive operation, FIG. 5 is a front view of the rear fall prevention method, and FIG. 6 is a front view of the rear fall prevention method. 1... Pedal, 2... Crank, 3... Brake, 4... Change lever, 5... Hub axle, 6...
...Bearing, 7...Hub bearing, 8...Hub bearing plate, 9...Sliding wheel, 10
... Spur gear, 11 ... Bolt, 12 ... Sliding button, 13 ... Pin, 14 ... Wheel hub, 15 ... Spoke hole, 16 ... Ball bearing, 17 ... Spur gear, 18 ... Gear shaft, 19...Gear shaft fixing plate, 20...Fixing ring, 21...One-way clutch, 22...Housing, 23...Crank stopper, 24...
Tension coil spring, 25...Wire holder, 26
...Compression coil spring, 27...Slide ball bearing,
28... wire cap, 29... cable wire, 30... wire holder, 31... joint plate, 32... tension coil spring, 33...
Lever shaft, 34...Change plate.

Claims (1)

[Claims] 1 The end of the wheel hub 14 is received by a ball bearing 16 placed in the circumference of a disc-shaped hub bearing plate 8 incorporating a bearing 6 centered on the hub axle 5, and is internally engaged with the wheel hub 14 opened on the side. The gear shaft 18 of the spur gear 17 is passed through and attached to the gear shaft fixing plate 19 with a hole through which the housing 22 incorporating the one-way clutch 21 with the hub shaft 5 as the shaft passes, and the pedal 1 is provided at the tip. The crank 2 connected to the frame by a tension coil spring 24 is passed between the gear shaft 18 and fixed to the housing 22, and the frame is provided with a crank stopper 23, and a sliding wheel 9 integrated with the spur gear 10 meshing with the spur gear 17 is mounted. Add a pin 13 to the side surface and drill a hole in the side surface of the wheel hub 14 on the outside of the wheelchair that incorporates the bearing 6 that serves as the hub axle 5 so that the pin 13 fits into the wheel hub 14. Provide enough space for the spur gear 10 to still not mesh with the spur gear 17,
The sliding button 1 in the hub axle 5 is made by inserting the bolt 11 into the sliding wheel 9 and boring it through a chiseled hole cut into the hub axle 5.
The cable wire 29 that pulls the center of the sliding bushing 12 and the cable wire 29 that pulls the center of the sliding bushing 12 through a compression coil spring 26 that is slightly compressed and inserted between the wire holder 25 fixed to the hub axle 5 and the sliding bushing 12. The lever 4 is connected to a tension coil spring 32 having enough force to compress the compression coil spring 26 whose tip is connected to the lever 4, and the left and right drive devices are configured such that the change lever 4 is stopped by a projection provided on the change plate 34. A front crank-driven wheelchair with independent wheels in the front and casters in the rear.