NO841016L - DEVICE FOR WHEELS WITH WHEELS, EX. WHEELCHAIR - Google Patents

Abstract

A wheelchair has two detachable, swingable attachments each comprising a footrest 8 and an obstruction-climbing device 9. Each device 9 comprises a sectorial strut 18 including an arcuate obstruction-contacting part 19 and arranged to turn about a horizontal pivot relative to the footrest 8. Acting between the strut 9 and the footrest 8 is a piston-and-cylinder damping device 15 of which the cylinder is oil-filled and contains a return spring. The damping device includes a piston rod of which the upper end zone 21 is of hook shape to hook over the pivot in an idle position (18) of the obstruction-climbing device 9.

Description

The present invention relates to a wheeled vehicle, additional equipment for this and a piston-cylinder device which the additional equipment may include. The invention relates in particular to step edge climbing devices for wheelchairs.

British patent document 1 569 166 describes an electric wheelchair with two large diameter driven rear wheels and two smaller diameter front link wheels. On the wheelchair's frame, two foot supports which can be rotated about respective vertical axes, as well as two step edge climbing devices, which comprise respective supports which can be rotated about a horizontal axis, are mounted at respective places above the link wheels. Each step edge claw assembly is attached to the frame by means of fasteners, including a bolt and a wing nut. Each support includes a curved mowing end which contacts the step edge to be overcome. A return spring works between the wheelchair frame and the support.

Each support can be rotated backwards from a standby position

where it runs downwards and forwards, against the action of the spring. IN

in a certain embodiment, when the spring returns the support to the standby position, an arm of the step edge climbing device will strike a locking piston mounted on the wheelchair frame.

Each piston can be retracted manually by a knurled pin against the action of the spring, so that the support can be swung back against the action of its return spring, past the piston. The piston is then released so that it holds back the support in an inactive position, where it extends backwards and upwards.

Each arm is pivotally mounted at one end on its support and is pressed with the other end against a stop by a spring, so that the spring gives way, if an abnormal force acts on the arm against its piston, e.g. when the wheelchair runs backwards over a step edge, while the arm remains in contact with its piston and no damage occurs. In another version shown, each support return spring is received in a cylinder, which is rotatably mounted on the wheelchair frame and through which a rod extends, surrounded by the spring and articulated with the support. In the support's standby position, a circular clip ("circlip") abuts an annular disc supported by the support's return spring. To bring the support into an inactive position, where it extends upwards and backwards, it is swung forward and above its pivot point to pass through a dead center position of the cylinder and the rod to the inactive position, where the circular clamp is again in contact with the annular disk. In a third version, each support return spring is a prestressed helical tor s.ion spring, the ends of which in the standby position press against opposite edges of protrusions attached to walls; on a device. To return the support to its resting position, a reciprocating pin is manually loosened to release the assembly for rotation relative to the wheelchair frame. After turning the support and the unit, the unit is again connected to the frame by engaging the pin.

Such step edge climbing devices have various disadvantages. Firstly, the impact of the support's construction elements against the impact of the frame when returning to emergency positions will cause jerks and noise, which can be unpleasant and embarrassing for the wheelchair user. Second, bolt and wing nut devices will make the release of the step edge climbing device from the frame difficult, compared to the conventional simple devices that allow easy release of the foot or leg supports from the wheelchair frames, especially for patients who sitting in a wheelchair. Thirdly, movement of the support from its standby position to its resting position requires either that a locking device, i.e. the piston or pin, be first released, which can be particularly difficult for a patient in a wheelchair, or circular clamps and washers come into contact against each other and thus induces both jolts and noise.

US-PS 2,612,379 shows additional equipment that can be attached

a vehicle, such as a handcart, and ■ which enables the cart to be pulled smoothly over steps. The additional equipment each includes a sector support which is rotatably mounted on the cart's frame and has a curved mowing end that comes into contact with the step edge. Between the support and the frame there is a coupling

piston-cylinder device, the piston of which is placed between two spiral springs to hold the support in the standby position. This equipment has a number of disadvantages, which make it unsuitable, especially for use in a wheelchair. First, the actual position of the support in the standby position tends to vary considerably, as the springs allow the support to swing back and forth. This often happens when the cart is handled rough on uneven terrain, with the result that the curved mower misses the edge of the step and the vehicle bumps hard against the step. Second, the equipment cannot be easily detached from the vehicle.

From DE-PS 2 922 963, a double-acting, shock-absorbing device for sliding doors etc. is known, which comprises a cylinder, which near its respective ends contains two pistons with one or two compression springs between them. Through the pistons protrude respective piston rods, which not only project axially forward from the housing for connection with sliding door parts, but also project radially inward from the pistons and are hollow, so that a damping fluid, located in the cylinder, can flow to the spaces between the pistons and their nearby cylinder ends. At the hollow, inner end of one piston rod, a piece of pipe is attached coaxially and extends towards the other piston rod. As the pistons are moved towards each other from their outermost positions, this piece of tube will approach the hollow inner end of the second piston rod and then begin to penetrate it. As the last-mentioned hollow inner end narrows conically, axially outwards, the free opening between the pipe piece and the hollow inner end decreases continuously. This device provides a progressively increasing damping effect by means of the damping fluid. In this shock absorber's rest position, the pistons lie against shoulders on the inside of the cylinder.

This shock absorbing device is unsuitable for use in vehicle devices for climbing obstacles, because the pistons are in contact with stops in the rest position and no noticeable damping effect is achieved in the rest position.

IN!

According to a first aspect of the present invention, a vehicle with wheels is provided, where at least one of the wheels is assigned a device to facilitate the meeting of this wheel with a step edge or a similar obstacle. Said device comprises a support, which is mounted on the vehicle for rotation<L>about a horizontal axis that is higher than the axis of the wheel, and a damping fluid is arranged to dampen the rotational movement of the support about said horizontal axis in a standby status of the support. The device is such that when the free end of the support hits the obstacle, it tilts on this obstacle and lifts the vehicle in the zone of the said wheel, so that the wheel can pass onto the obstacle.

An advantage of this vehicle is that the support can be reliably held in a relatively fixed standby position without the support's return to the standby position causing significant shocks or noise.

According to another aspect of the present invention, there is provided a wheeled vehicle comprising a frame and additional equipment which is removably mounted on the frame. At least one wheel of the vehicle is assigned a device to facilitate the wheel's encounter with a step edge or a similar obstacle. Said equipment comprises said device and a support for one of the vehicle user's feet or legs.

According to a third aspect of the present invention, there is provided a device for removable mounting on. a frame for a wheelchair, where the equipment comprises a device for assignment to one of the vehicle's wheels to make it easier for the wheel to overcome an obstacle, e.g. in the form of a curb, as well as a support for one of the vehicle user's feet or legs.

Such a combination of a device for overcoming obstacles and a foot or leg support means that the combined equipment can be easily removed from the vehicle as a single unit. According to a fourth aspect of the present invention, there is provided a vehicle with wheels, where at least one of the wheels has an associated device to make it easier for the wheel to come up on a step edge or a similar obstacle. This device comprises a support which is mounted on the vehicle for rotation about a horizontal axis, which is higher than the wheel axle, a spring, which is arranged so that it applies a moment to the support to keep the support in a standby position, where the support can is rotated about said axis from the standby position, where springs exert a moment on the support in a direction around said axis, to a resting position, where the spring exerts a moment on the support in the opposite direction and stoppers maintain the support in said resting position, and - an elongated member, using of. which spring affects the support, where the elongate member is connected to a portion of the spring which remains in a substantially fixed position relative to the elongate member throughout the movement of the support between the standby position and the rest position, and where the arrangement is such that when the support free end in standby position comes into contact with the obstacle, it will tip over the obstacle and lift the vehicle in the wheel zone, so that the wheel can roll onto the obstacle.

The device which ensures that the above-mentioned spring part remains in an essentially fixed position in relation to the elongate member has the advantage that movement against a stop is avoided so that the resulting impact and noise and wear are also avoided.

According to a fifth aspect of the present invention, there is provided a piston-cylinder device, which comprises a spring arranged in the cylinder to act between the piston and the cylinder, a stop which carries one end of the spring and is arranged for longitudinal movement with either piston or cylinder in relation to the other part, where the cylinder and the piston are rotatable in relation to each other about the cylinder axis for adjusting the stop along the piston or the cylinder, so that one end of the spring is adjusted along the piston or the cylinder.

in

This device has the advantage that the rest position of the piston in relation to the cylinder can be easily adjusted.

In order for the invention to be easier to understand and implement, reference is now made to some examples of execution shown in the drawing, where

fig. 1 shows a side view of a motorized wheelchair in use,

while moving up a curb-like obstacle,

fig. 2 shows a side view of an equipment unit for the wheelchair, comprising a device for climbing up obstacles which is shown in solid lines in the standby position and in dashed lines in the rest position,

fig. 3 shows a front view of the equipment unit in which the device for climbing obstacles is in the standby position and

fig. 4 shows a section through a piston-cylinder device. for the device to climb on obstacles.

With reference to the drawing, the wheelchair 1 has two rear wheels with a large diameter (one of which is shown and designated by 2), which can be driven back and forth by respective electric motors (one of which is shown and designated by 3) . The wheelchair 1 also includes two steering wheels 4 at the front, where the wheels 2 and 4 are mounted on a wheelchair frame that can be folded in a transverse direction. At the front, the wheelchair frame comprises two uprights (one of which is visible and denoted by 6), on which respective equipment units 7 are mounted so that they can be pivoted around the uprights from the forward-swinging position shown in fig.

1 and out to positions where they can be taken by the uprights.

Each equipment unit 7 comprises a foot support 8 and a device

9 for climbing obstacles, mounted on the footrest 8. The footrest 8 and the device 9 can thus be dismantled from the wheelchair frame as a unit for temporary replacement. tte's media. ! {one j ordinary foot support unit where this is necessary to reduce the width of the wheelchair, e.g. for the wheelchair to be able to pass through a doorway, or in cases where it is not necessary to get up onto curbs etc. In a conventional manner, the foot support 8 comprises two horizontal plates 10, by means of which it is mounted on two vertical pivots which are attached to the upright 6. The plates 10 are attached to a tubular bracket 11, of which a projecting part 12 rotatably supports a foot pad 13. A horizontal pivot

14 is attached to and protrudes to the side from part 12, and on

this is the lower end of a cylinder 15 for a cylinder-piston device 15,16 of the device 9 rotatably mounted. A horizontal shaft 17 is attached to the upper part of the bracket 11 and a sector support 18 is rotatably mounted on this. The support 18 comprises a curved part 19 for contact with obstacles. The piston 16 comprises a piston rod 20, whose upper end zone 21 has the shape of a hook and ends on the axis A of the device 15, 16. At this end it is horizontally jointed with a horizontal sleeve 32 for the support 18 by means of a horizontal nut -bolt device 33. The cylinder 15 is filled with oil and sealed in a liquid-tight manner at both ends. At its upper end, it is sealed with a plug 22, which sealingly surrounds the piston rod 22. The plug 22 comprises a bushing 23 which is designed with an axially downward-facing, truncated conical bearing surface 24, which carries

, upper end of a spiral spring 25, which surrounds the piston rod 20. The lower zone of the piston rod 20 is designed with an external thread 26. Here, an internally threaded bushing 27 is screwed on and designed with an axially upward-facing, truncated cone-shaped surface 28, which carries the lower end of the spring 25. Two nuts 2 9 are screwed onto the lower end of the piston rod 20 and clamp a disc 30 between them. Between the disk 30 and the inner cylinder wall of the cylinder'15 is a clearance, through which the oil in the cylinder can be forced to flow.

The procedure for using the device 9 to climb obstacles is as follows: The support .18 is normally in its standby position as shown in fig. 2, where it is held by the torque in the clockwise direction induced by its own weight being counteracted by the torque against the pointer direction induced by the spring 25. The damping created by the oil in the cylinder 15 will essentially prevent unwanted oscillating movement of the support in standby position while the wheelchair is moving. During such driving, the steering wheels 4 themselves will force smaller obstacles onto the ground or floor, such as e.g. obstacles with a height of 2.5-5 cm height. But obstacles above this general height and up to 12.7 cm can be forced by means of the device 9. When the wheelchair approaches the obstacle 31, will. the parts 19 for contact with the obstacle come into contact with the obstacle. The continued operation of the wheelchair's motor and thus the continued operation of its rear wheels will cause each support 18 to tilt on the obstacle, while the wheelchair rolls forward against the action of the spring 25 and against the dampening effect of the oil in the cylinder 15,

and lifts the front of the wheelchair (e.g. via the state shown in fig. 1), until the wheels 4 roll on top of the obstacle 31. Then each support 18 is swung back to the standby position as shown in fig. 2 by means of the spring 25, but against the damping effect of the oil in the cylinder 15. The rear wheels have a sufficiently large diameter to be able to force the obstacle 31 simply by means of the engine power. In order for the support 18 to be brought into a resting position, where it is out of the way of the footrest 8, so that it will be easier to maneuver in conditions where the surface is flat, but where it is narrow, it can be swung clockwise from the standby position as shown in fig. 2 to a resting position 18', which is indicated by dashed lines^ in fig. 2. In this state of the device 9, the hook-shaped zone 21 is curved over and in a.nlay. against the bøs-singen 32, as indicated at 21'. In this state, the axis A is displaced in a vertical plane and through the horizontal axis of the axis 17, so that the spring 25 presses the support 18 with a torque in the clockwise direction. This moment is significantly greater than the counter-clockwise moment which is caused by the weight of the support in this position 18'. The support is thus held in that position until it is desired to move it back clockwise to the standby position. The wheelchair user can initiate this by simply pressing the support, 18 j

rode through the dead center position. The end of the spring 25 which is located near the bushing 27 remains in contact with this undeo: the entire movement of the piston rod 20 in relation to the cylinder 15.

The connection of the upper end of the piston rod 20 with the bushing 3 2 by means of the nut-bolt device 33 makes it possible to

disassemble the piston rod'20 from the bushing 32 and rotate it about the axis A. Such rotation is necessary for adjusting the compression in the spring 25 for a given length of the device 15,16, so that angular adjustment of the support 18 standby position will be possible. Rotation of the piston rod 20 leads to such adjustment because it screws the bushing 27 along the piston rod 20. The bushing 27 is held against rotation with the piston rod 20 by the fixation forces between the ends of the spring 25 and the cut-off conical bearing surfaces 24 and 28 of the bushings 23 and 27.

Claims (1)

1. Wheelchair, where at least one of the wheels (4) has an assigned device (9) to facilitate the wheel's (4) pushing a curb or a similar obstacle (31), where the device The device (9) comprises a support (18), mounted on the vehicle (1) for rotation about a horizontal axis which is higher than the axis of the wheel (4), and a damping device (15, 16), which is arranged to dampen the support (18) turning movement about said horizontal axis, where the device is like this. that when the free end (19) of the support (18) hits an obstacle (31), it will tilt on the obstacle (31) and lift the vehicle (1) in the zone of the wheel (4) so as to enable the wheel (4) to pass up on the obstacle (31), characterized in that the damping device (15, 16) is a liquid damping device (15, 16), designed to dampen said rotational movement to the standby position of the support (18). 2. Vehicle as specified in claim 1, characterized by . that the liquid damping device (15, 16) comprises a cylinder (15) containing the damping liquid, a piston head (29, 30) in the cylinder, a piston rod (20), which is connected to the piston head (29, 30), openings through which the fluid can flow from one axial side of the piston head (29,30) to the other in a choked manner, and a return spring (25), which is arranged to return the support (18) to the standby position after the support (18) ) has tipped over the obstacle (31). 3. Vehicle as stated in claim 2, characterized in that the return or return spring (25) extends between the piston head (29,30) and one end of the cylinder (15) and surrounds the piston rod (20), which is connected to an end portion of the spring (25), which remains in a substantially fixed position relative to the piston rod (20) throughout the movement of the support (18). j4.' Vehicles as stated in claim 2, character-, characterized by the return spring (25) extending between the piston head (29, 30) and one end of the cylinder (15) and surrounding the piston rod (20) and that on the piston rod (20) there is a stop (27) which carries one end of the spring (25) and is arranged to be moved longitudinally with the piston (16), where the piston (16) and the cylinder (15) are rotatable in relation to each other about the axis of the cylinder (15) for adjusting the stop (27) along the piston rod (20), so that said one end of the spring (25) is adjusted along the piston rod (20). 5. Vehicle as specified in claim 4, characterized in that the stop (27) has a member (28) which counteracts rotation of the stop (27) in relation to the piston rod (20) about the piston rod (20) and where the other end of the spring (25) is in contact with the cylinder (15) by means of organs (24) which prevent rotation of the spring (25) in relation to the cylinder (15). 6. Vehicle as stated in one of the preceding claims, characterized in that the support (18) is rotatable from the emergency position, where the spring (25) presses the support (18) a moment in a direction around the said axis, to a rest position (181), where the spring (25) applies a moment to the support (18) in the opposite direction and where stoppers (21,3 2) hold the support (18) back in the rest position (18 <1> ). 7. Vehicle as stated in claim 6, characterized in that the cylinder (15) is mounted for rotation about a transverse end, horizontal axis, remote from the outer end (21) of the piston rod (20), and that the stops (21,32) comprises a stopper (3 2) which is arranged on the axis of rotation of the support (18), and a hook-shaped part (21) of the piston rod (20) outside the cylinder der (15) and arranged to grip around and come to rest against the stopper (32) in the rest position (18') of the support (18). 8. Wheeled vehicle, comprising a frame (6) and an equipment unit (7), which is removably mounted on the frame (6) and ■ iomcomprises a support ( 8) for one of the vehicle user's feet or legs, where at least one wheel (4) of the vehicle (1) has an assigned device (9) to facilitate the wheel (4) pushing a curb or a similar obstacle (31), characterized in that the equipment unit (7) also includes the device (9). 9. Equipment unit for removable mounting on a frame for a wheelchair, where the equipment (7) comprises a support (8) for one of the wheelchair user's feet or legs, characterized in that the equipment (7) also comprises a device (9) for assignment to a wheel (4) of the vehicle (1) to facilitate the pushing of the wheel (4) by a curb or a similar obstacle. 1C. Wheelchair, where at least one of the wheels (4) has an associated device (9) to facilitate the wheel's (4) pushing a curb or a similar obstacle (31), where the device comprises a support (18), which is mounted on the vehicle (1) for turning about a horizontal axis which is higher than the axis of the wheel (4), a spring (25) which is arranged to apply a moment to the support (18) to keep the support (18) in a standby position, where the support (18) is rotatable about said axis from the standby position, where the spring (25) presses on the support (18) a moment in a direction around said axis to a rest position (18'), where the spring (25) presses on the support (18) a moment in opposite direction and stoppers (21,32) hold, back the support (18) in said rest position (18 <1> ), and an elongated member (20), by means of which the spring (25) affects the support (18), where the device is such that when the free end of the support (18) in the standby position hits the obstacle (31), it will tip over the obstacle (31) and lift the vehicle yet (1) in the zone of the wheel (4) and thus enable the wheel (4) to pass up the obstacle (31), characterized in that the elongated member (20) is connected to a part of the spring (25), which remains in an essentially fixed position in relation to the elongate member (20) below .the entire movement of the support (18) between the standby position and the rest position (18 <1> ). 11. Piston-cylinder device comprising a spring (25), which is arranged in the cylinder (15) and acts between the cylinder (15) and the piston (16), a stop (27) in contact with one end of the spring (25 ) and arranged to move in the longitudinal direction together with either the piston (16) or the cylinder (15) in relation to the other part, characterized in that the cylinder (15) and the piston (16) are rotatable in relation to each other about the cylinder's (15) axis for regulating the stop (27) along either the piston (16) or the cylinder (15), so that said one end of the spring (25) is regulated along the piston (16) or the cylinder (15).