JP3085053U - Wheelchair drive - Google Patents

Abstract

(57) [Summary] [Problem] A pair of operation rods are pivotally supported on both sides of a wheelchair body,
At the tip of the swinging rod pivotally supported on the axle of the drive wheel, a lug-shaped claw is pivotally supported opposite the tread surface of the drive wheel, and the swinging rod swings to the drive wheel rotation side in conjunction with the operation rod. An object of the present invention is to provide a wheelchair driving device in which a pawl is pressed against a tread surface of a driving wheel to be driven. SOLUTION: A base end of a swinging rod 6 is pivotally supported on an axle 3 which supports a driving wheel 4 on both sides of a vehicle body 2 of a wheelchair 1, and protrudes from a tread surface 5 of the driving wheel 4 to protrude therefrom. In order to pivotally support the base end of the claw with a claw pin 9, a half-moon-shaped friction surface 8 formed on the claw is arranged in the rotation direction of the tread surface, and a bracket 10 protruding on both sides of the vehicle body is operated. The rod 11 is pivotally supported, and the crank pin 12 of the operation rod is slid into a slot 13 provided in the middle of the swinging rod 6. An operation wire 16 inserted into the wire guide 15 is connected between the guides, and a return spring 17 is provided between the guide and the lug 7.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to a driving device for a wheelchair.

[0002]

[Prior art]

 Conventionally, in general, a hand rim juxtaposed to the outside of a large-diameter drive wheel of a wheelchair is generally placed in a sitting position, and repetitive operations are performed to push both hands forward from above the rim, thereby driving the drive wheel to propell. It is practiced to operate both rims at the same time to go straight, and operate one rim to steer.

[0003] Further, there is a vehicle in which a transmission is interposed between a driving wheel and a hand rim so that the rotating direction of the hand rim and the rotating direction of the driving wheel are opposite to each other (for example, see Japanese Utility Model Publication No. 5-221171).

[0004] Instead of rotating the hand rim, a reciprocating lever is used to drive the drive wheels via the gear transmission and the first one-way clutch in the forward stroke of the lever, and in the return stroke. There is a drive device that drives the drive wheels in the same direction via a reverse gear unit and a second one-way clutch, so that the drive wheels are driven forward by reciprocation of a lever (for example, a real drive). No. 6-30179).

[0005] Further, there is a type in which a one-way clutch is interposed between the large-diameter wheel and the hand rim, and the large-diameter wheel is driven in the forward direction by gripping and swinging the hand rim (for example, actual climb 3 005373). No.).

[0006]

[Problems to be solved by the invention]

 As described in the background of the prior art, the operation of a normal wheelchair using the hand rim is such that in a sitting position, the pushing operation of the free upper limb forward or forward and downward is the inputting operation to the driving wheel, and the pulling in the opposite direction is performed. The approaching movement is a return action, and the maximum muscular strength of the pushing action is slightly larger than the maximum muscular strength of the pulling action, but the strength of the normal continuous motion range is larger in the latter case. (Hunsicker, 1955), when the occupant grasps the hand rim and performs the driving operation, the upper limb muscle expands and contracts unnaturally, the upper body unnaturally leans forward, and is accompanied by compression in the dorsal position. The efficiency of conversion to driving force is lower than that of the occupant, and the occupant repeats a rapid forward leaning posture, which may be insecure. Improve the input operation and input posture, these disadvantages Wheelchair drive wheel drive means to solve is desired.

[0007] Further, in the prior art in which the drive wheels are driven by a pair of gears on both sides of a wheelchair and a one-way clutch, the structure of the transmission system is complicated, the transmission efficiency is reduced, and the input operation is also complicated. Tend to be.

[0008] The present invention has been made in view of such problems in the prior art, and a purpose thereof is to pivotally support a pair of operation rods on both sides of a wheelchair body, and to provide an axle for driving wheels. A lug-shaped claw is pivotally supported at the tip of the pivoted swinging rod in opposition to the tread surface of the drive wheel, and the swinging rod is swung to the drive wheel rotation side in conjunction with the operation rod, and the claw is moved to the drive wheel rotation side. It is an object of the present invention to provide a wheelchair driving device which is driven by pressing on a tread surface.

[0009]

[Means for Solving the Problems]

 In order to achieve the above object, the wheelchair driving device of the present invention pivotally supports the base end of the swinging rod on the axle supporting the driving wheel on both sides of the body of the wheelchair, and places the swinging end outside the tread surface of the driving wheel. The lug is protruded to the base and the base end side of the lug is pivotally supported by the lug pin.The lug surface formed on the lug is arranged in the direction of rotation of the driving wheel tread, and both sides of the vehicle body A bell crank-shaped operation rod is pivotally supported on the bracket protruding from the operation rod, and the crank pin of the operation rod slides into the slot provided in the swing rod, and the brake lever is pivoted in the middle of the operation rod. An operating wire inserted into the wire guide is connected between the lever and the lug, and a return spring is interposed between the guide and the lug.

[0010] In the wheelchair driving device configured as described above, in the original position where the brake lever is not operated, a return spring interposed between the wire guide and the moon-shaped claw causes the friction surface of the claw to be in contact with the lubrication surface. The contact between the drive wheel and the tread surface is separated, and the pull-out stroke in which the operating rod is rotated from the front side to the back side in the chair sitting position and the push-back stroke in the opposite direction are performed regardless of the driving state of the drive wheel. It can be operated freely to any position in both directions.

[0011] Then, when the brake lever is operated and the frictional surface of the lug is slightly in contact with the tread surface of the driving wheel via the operation wire, the operation rod is rotated by the pulling stroke. Slides in the slot to rotate the swinging rod in the rotation direction of the drive wheel, and the initial frictional force at the contact point between the friction surface and the tread surface causes the radial direction between the contact point and the center of the claw pin. And the pressing force as a component force in the driving wheel radial direction, and the friction surface is displaced to the side where the friction surface is pressed against the tread surface by the moment of the component force in the driving wheel radial direction with respect to the center of the claw pin. A tendency to self-lock (self-locking) by automatically amplifying the pressing force and frictional force on the tread surface of the friction surface, driving the drive wheels with the rotation of the swinging rod, and propelling the wheelchair. Become.

Next, when the operation rod is stopped or operated to the push-back stroke, the component of the friction force at the contact point between the friction surface of the lug nail and the tread surface of the driving wheel in the radial direction of the driving wheel is reduced by the lug nail. It becomes a force to push up from the tread, and it tends to displace to the side that separates the claw from the tread by the moment of the same force related to the claw pin, causing slip at the same contact point and not braking the rotating drive wheel.

When the brake lever is relatively strongly operated at an arbitrary position of the operation rod and the friction surface of the lug is pressed against the tread surface of the driving wheel via the operation wire, the friction surface and the tread surface are disengaged. A frictional force is generated by the pressure contact force to prevent the sliding displacement, and the swinging rod and the driving wheel are integrally operated according to the operation of the pulling stroke or the pushing back stroke of the operating rod, and the driving wheel is moved forward or forward. Drive in any direction to the reverse side.

As described above, the wheelchair can be arbitrarily selected by combining the operation of the brake lever with the operation stroke, the size, the speed, and the operation force of the operation rods on both sides, and operating the operation rod on one side independently. And steer by driving in the direction of.

[0015]

[Embodiment of the invention]

 An embodiment of the present invention will be described with reference to the drawings based on an embodiment. In FIGS. 1 to 4, a large-diameter drive wheel 4 is supported on an axle 3 on both sides of a vehicle body 2 of a wheelchair 1 and the outer side of the axle 3 is provided. In order to pivotally support the base end of the swinging rod 6 coaxially and project the swinging end to the outer periphery of the tread surface 5 of the drive wheel 4 to pivotally support the base end side of the lug 7 with the claw pin 9, A half-moon-shaped friction surface 8 formed on the claw is arranged in the direction of rotation of the driving wheel tread surface, and a fulcrum of a bell-crank-shaped operation rod 11 is pivoted on a bracket 10 protruding on both sides of the vehicle body 2. The crank rod 12 of the operating rod is slid into a slot 13 provided in the middle of the swinging rod 6, and a brake lever 14 is pivotally supported in the middle of the operating rod 11. An operation wire 16 inserted through a flexible wire guide 15 is connected between the nail 7 and the guide and the lug. It is interposed a return spring 17 between the.

In the wheelchair driving apparatus configured as described above, as shown in FIGS. 1 and 2, in the original position where the brake lever 14 is not operated, the wheel guide 15 is interposed between the wire guide 15 and the lug 7. The contact between the friction surface 8 of the claw and the tread surface 5 of the driving wheel 4 is separated by the return spring 17, and the operating rod 11 is moved from the front position a to the rear position of the chair sitting position regardless of the driving state of the driving wheel 4. It is possible to freely rotate to any position in both directions of the pulling strokes a to b operated in the direction b and the push-back strokes ba to a in the opposite direction.

Then, as shown in FIG. 4, when the swinging rod 6 is rotated from the original position a in the rotation direction b of the driving wheel 6 via the crank pin 12 in the pulling strokes a and b of the operating rod 11. The frictional force f in the tangential direction, which is opposite to the rotational direction of the driving wheel, at the contact point between the friction surface 8 of the lug 7 and the tread surface 5 of the driving wheel 4, and the lug movement between the lug pin 15 center and the same contact point Assuming that the angle of intersection with the radius is θ, the frictional force f is decomposed into components of the component force fsecθ in the radial direction of the lug claw and the component force ftanθ in the radial direction of the driving wheel. The component force fsecθ of the former keeps an equilibrium state as the internal stress of the lug 7, and the component force ftanθ of the latter becomes the pressing force between the tread surface 5 and the friction surface 8 at the same contact point, and the moment about the claw pin 9 The above-mentioned intersection angle tends to be displaced toward the side where θ gradually increases, and the intersection angle θ gradually becomes a right angle. Then, the same component force ftanθ, that is, the same pressing force is automatically amplified rapidly, and the contact between the tread surface 5 and the friction surface 8 is in a self-locking (self-locking) state, and the driving wheel 4 is integrally formed with the swinging rod 6. To drive the vehicle in the forward direction.

On the other hand, in the push-back stroke b-a in which the vicinity of the power point of the operating rod 4 is pushed out from the rear side b of the occupant to the front side a, the swinging rod 6 rotates in the rotation direction of the driving wheel 4. And the residual pressing force at the contact point between the friction surface 8 and the tread surface 5 generates a friction force f ′ in the drive wheel rotation direction, and the angle of intersection between the friction force and the lug radius is θ The friction force f 'is decomposed into a component of a lunar claw radial component f'secθ and a component of a drive wheel radial direction f'tanθ, both of which exceed the friction force f'. Is maintained as equilibrium as the internal force of the lug 7, and the latter is a repulsive force in the opposite direction to the pressing force. The frictional force at the same contact point gradually decreases together with the component force f'tanθ, To release the self-locking (self-locking) state, a state to slide in each other and the moon pawl 7 and tread 5, it is not name that prevent rotation state and forwarding state of the drive wheels 4.

When the brake lever 14 is relatively strongly operated at an arbitrary position of the operation rod 11 and the friction surface 8 of the lug 7 is pressed against the drive wheel tread surface 5 via the operation wire 16, Due to the pressing force between the friction surface and the tread surface, a frictional force f or f 'is generated according to the operation of the pulling stroke a-b or the pushing back stroke b-a of the operating rod 11, thereby preventing the sliding displacement. 6 and the drive wheel 4 are integrally operated to drive the drive wheel 4 forward or backward.

As described above, the operation direction, the size, the speed, and the operation force of the operation of the brake lever 14 and the operation of the operation rods 11 on both sides are respectively combined, and the operation of the operation rod 11 on one side is independently performed. The wheelchair 1 is driven in an arbitrary direction and steered.

[0021]

[Effect of the invention]

 Since the present invention is configured as described above, the following effects can be obtained.

In the wheelchair driving device according to the first aspect, by directly driving the driving wheel by pressing the tread surface of the driving wheel by the moon-shaped pawl, there is no transmission loss due to the one-way clutch and the gear transmission device in the prior art. The transmission efficiency from the operating rod to the drive wheels can be improved.

The operation rods on both sides of the vehicle body are pulled from the front side in the chair sitting position to apply driving force to the driving wheels by a pulling operation, and are smoothly returned to the front side position by the pushing back operation. Since the posture displacement is small and the upper extremity muscles naturally expand and contract, the conversion efficiency to driving force is good, and the operation can be performed comfortably with less fatigue. As compared with the operation of repeating the unnatural forward leaning posture associated with the above, the conversion efficiency to the driving force is lower, and it is possible to eliminate various disadvantages that tend to cause fatigue and lack safety.

Also, by operating the brake lever, it is possible to change the contact state between the lug-shaped pawl and the tread surface of the driving wheel, so that the operating direction, size, speed and operating force of the operating rod can be changed in combination. The wheelchair can be steered by driving in any direction.

Further, by operating the brake lever, the lug-shaped pawl and the tread surface of the drive wheel are strongly pressed against each other to prevent mutual sliding, and by restraining the operation rod from swinging, the drive wheel is restrained. Can be braked.

[0025] Then, by driving directly by pressing the tread surface of the drive wheel with the lug-shaped pawls, there is no need to provide a transmission device such as a one-way clutch and gears in the conventional technology, and a simple and lightweight structure is provided. As a result, a low-cost drive device with few failures can be provided.

[Brief description of the drawings]

FIG. 1 is an elevational view of a wheelchair drive.

FIG. 2 is an elevational view of details of a main part of FIG. 1;

FIG. 3 is an elevation view as viewed from the arrow A in FIG. 1;

FIG. 4 is a schematic view showing an operation state of a main part of FIG. 2;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Wheelchair 2 Body 3 Axle 4 Driving wheel 5 Tread surface 6 Oscillating rod 7 Moon shaped claw 8 Friction surface 9 Claw pin 10 Bracket 11 Operation rod 12 Crank pin 13 Slot 14 Brake lever 15 Wire guide 16 Operation cable 17 Return spring 18 Caster f Friction force (during operation rod pulling stroke) θ Intersection angle between friction force and lug nail radius ftanθ Component force in the drive wheel radial direction (during operation rod pulling stroke) fsec θ Lunar jaw radial direction component Force (during the operation rod pulling stroke) f 'friction force (during the operation rod pushing stroke) f'tanθ Component force in the driving wheel radial direction (during the operation rod pushing stroke) f'secθ lunar claw radial direction Component force (in operation rod pushing stroke) a-b Pulling stroke (of operation rod) b-a Push-back stroke (of operation rod)

Claims (1)

[Utility model registration claims] 1. A base end of a swinging rod (6) is pivotally supported on an axle (3) supporting a driving wheel (4) on both sides of a vehicle body (2) of a wheelchair (1) to drive the swinging end. The lug (4) is protruded to the outer surface of the tread (5) and the base end of the lug (7) is pivotally supported by the lug pin (9). ) Is arranged in the direction of rotation of the drive wheel tread surface, and a bell crank-shaped operation rod (11) is pivotally supported on a bracket (10) protruding on both sides of the vehicle body (2). Crank pin (1
2) slides into a slot (13) provided in the middle of the swinging rod (6), and pivotally supports a brake lever (14) in the middle of the operating rod. Between them, an operation wire (16) inserted through a wire guide (15) is connected, and a return spring (17) is provided between the guide and the lug (7).
A wheelchair driving device interposed.