EP1893153A1

EP1893153A1 - Wheelchair with central wheel drive

Info

Publication number: EP1893153A1
Application number: EP06741656A
Authority: EP
Inventors: Kurt Hunziker; Samuel HÜRLIMANN; Alexandre Tapis
Original assignee: Degonda-Rehab Sa; Degonda Rehab SA
Current assignee: Degonda-Rehab Sa; Degonda Rehab SA
Priority date: 2005-06-24
Filing date: 2006-06-16
Publication date: 2008-03-05
Anticipated expiration: 2026-06-16
Also published as: EP1893153B1; US20090321162A1; ATE520384T1; US8186463B2; WO2006136046A1

Abstract

A wheelchair has two central wheels that can be separately driven by a motor. In order to allow the wheelchair to turn around in narrow spaces, the central wheels can be driven in opposite directions of rotation. When the wheelchair is turned around, the front wheels and rear wheels do not constitute a hindrance because they are kept at a distance from the ground by the swiveling wheel. All three wheels are coupled together on each side by a chain. When the front wheels run against an obstacle, the wheelchair climbs over the obstacle with the driven front wheels. This causes the fork of the swiveling wheel to swivel about the rotational axis in the direction of arrow, against the force of a spring, bringing the rear wheels in contact with the ground and also driving the wheelchair's rear wheels. This all-wheel drive allows the wheelchair to overcome relatively high obstacles both forwards and backwards, even when driving slowly and without losing its maneuverability.

Description

Wheelchair with Mittenradantrieb

The invention relates to a wheelchair with Mittenradantrieb, with two center wheels, which are separately driven by a motor, at least one front wheel and at least one rear wheel, wherein the rear wheel or the front wheel is in a position above the driving level. When wheelchair is mentioned here, this is generally understood in the sense of motor-driven vehicles for the disabled.

For example, US 5,904,214 shows a wheelchair with Mittenradantrieb with two center wheels, two designed as swivel wheels front wheels and a

Rear wheel, which is located in a position above the driving level and is driven by a motor. Each of the two center wheels is separately driven by a motor. This has the advantage that the wheelchair in a confined space, z.Bsp. in an elevator car, can be turned. To turn in place, the wheelchair user operates the controller so that the two center wheels are rotated in opposite directions. The front wheels must not hinder the turning. Therefore, the front wheels are designed as swivel wheels. However, this wheelchair has the disadvantage that obstacles, if they exceed a certain height, can not be overcome in slow speed. Also, the wheelchair described has, for example, in snowy roads a relatively low grip and is no longer able to drive up a relatively steep ramp.

hi the US 6712369 a wheelchair with two center wheels, two pivoting front wheels and two rear wheels is described. To drive the center wheels a single motor is provided, but it is mentioned that other suitable drive means may find application. The rear wheels have no drive, are not pivotable and are not in contact with flat ground. But they can be moved against the force of springs upwards. In contrast T / CH2006 / 00033!

to the previously described known wheelchair but the rear wheels have no motor drive. The wheelchair according to the US 6712369 is not able to overcome relatively high obstacles in slow driving. With a little skill, however, such obstacles can be overcome. Namely, if the wheelchair is greatly accelerated, the springs of the rear wheels are pressed together and raised the front wheels, so that they can overcome the relatively high obstacle. However, most wheelchair users feel insecure during such maneuvers. Such maneuvers may not even be ventured by some wheelchair users because they could be injured by vibrations or shocks. Another disadvantage is that in poor condition of the road, z.Bsp. in snow, the driving characteristics of the wheelchair to be desired, as it has only two driven wheels.

Already in WO 96/15752 was proposed on page 15, line 10 with reference to FIG. 14, the front wheels increased, ie without ground contact, to arrange, as was later proposed in US 6,129,165. This makes it easier to overcome an obstacle. But this is not the case when reversing, because only the front wheels are arranged elevated.

It is therefore an object of the present invention to provide a wheelchair with center drive, which is able to overcome both relatively large obstacles at a relatively low speed both when driving forward and when reversing and also has good handling characteristics, for example on snowy roads, but still the advantages of Mittenradantriebs has in particular the ability to turn in a small space.

Effindungsgemäss this is achieved in a wheelchair of the type mentioned in that the rear wheel and / or the front wheel is driven by a motor and that in the vicinity of the rear wheel and / or the front wheel at least one 6 000331

Pivoting wheel is provided, which holds the rear wheel and / or the front wheel in an elevated position above the driving plane, but is adjustable in height to allow in overcoming obstacles to the rear wheel or the front wheel ground contact. Since normally neither the front nor the rear wheel are in contact with the ground, they are not a hindrance when turning the wheelchair. Thanks to its elevated position, the front wheel can easily overcome this when hitting an obstacle. The same applies to the rear wheel when reversing. There is also no need to train these wheels as swivel wheels. They can therefore be designed as driven wheels to give the wheelchair when overcoming obstacles or, for example, in snow-covered road the properties of an all-wheel drive. Conveniently, therefore, both the front wheel and the rear wheel are driven by a motor. To increase the stability and to improve the driving characteristics, a front wheel is expediently provided on each side of the wheelchair. For the same reasons, a rear wheel is advantageously provided on each side of the wheelchair. For the wheels of each side of the wheelchair a Mittenrad, a front wheel and / or a rear wheel can be arranged and each provided a common drive. This can be done for example by means of an endless chain or an endless toothed belt, a gear transmission, a cardan drive or other mechanical device. A common drive could also be realized by hydraulic means.

The swivel wheel is conveniently held by spring force in the normal position in which the Vorderrrad and the rear wheel are in a position above the road, in which they do not hinder the turning of the wheelchair. But it would also be possible to provide a motor to adjust the pivot wheel in height.

The respective swivel wheel is expediently arranged in the middle between the rear wheels or the front wheels. 6 000331

The invention also relates to a wheelchair with Mittenradantrieb, which has two center wheels, which are separately driven by a motor, has at least one front wheel and at least one rear wheel, wherein the front wheel is in an elevated position above the driving level. This wheelchair according to the invention is characterized in that the front wheel is driven by a motor and that the rear wheel is designed as a swivel wheel. Thanks to the rear wheels designed as swivel wheels, this wheelchair can also be used in confined spaces. Even overcoming obstacles is easy to accomplish when driving forward thanks to the elevated position of the front wheels above the driving level and their motor drive. But if a much easier overcome of

Obstacles also when reversing is desired, it is expedient, as previously stated, to provide motor drive for all wheels.

Embodiments of the invention will now be described with reference to the drawings.

It shows:

1 shows a first embodiment of a wheelchair with Mittenradantrieb in a schematic representation,

FIG. 2: a side view of the wheelchair of FIG. 1,

Figure 3: a side view of between the two rear wheels of

Wheelchair arranged swivel wheel,

FIG. 4: the wheelchair when ascending an ascending path,

FIG. 5: the wheelchair when descending a sloping section,

Figure 6: different phases of overcoming an obstacle in the

Drive forward, Figure 7: different phases of overcoming an obstacle in the

Drive backwards,

Figures 8a to c: a second embodiment of a wheelchair with

Mittenradantrieb, in which only the middle and rear wheels are driven by a motor,

Figures 9a to d: a third embodiment of a wheelchair in which only the middle and front wheels are driven by a motor.

10 shows a fourth embodiment of a wheelchair with center drive, which front and rear has a swivel wheel,

FIG. 11 is a front perspective view of the wheelchair of FIG. 10;

FIG. 12 is a rear perspective view of the wheelchair of FIG. 10;

FIG. 13: a swivel wheel designed as a twin wheel with suspension by means of a spring joint,

FIG. 14 shows the swivel wheel of FIG. 13, but with one of the twin wheels being omitted, so that the spring joint can be seen,

FIG. 15 shows a further embodiment of a swivel wheel, in which two

Spring joints are provided to allow a greater deflection. 31

The wheelchair according to the figures 1 to 3 has a chassis 11 and a seat mounted thereon 13. This can be configured arbitrarily, z.Bsp. also as an erecting rack to allow the user to move from the sitting position to the upright position. The wheelchair has two center wheels 15, two front wheels 17 and two rear wheels 19. It would also be possible z.Bsp. to provide only a rear wheel 19 in the vehicle center. As can be seen from FIGS. 2 and 3, a swivel wheel 21 'is located between the rear wheels 19. The swivel wheel 21 'is advantageously formed as a sprung Zwülingsrad (Fig. 12 to 15).

Each of the two center wheels 15 is separately driven by a motor (not shown). This makes it possible to turn the wheelchair in a small space by the Mittenrad 15 is driven in one direction by the one motor and the other Mittenrad 15 by the other motor in the opposite direction. In this turn, the pivot wheel 21 'may rotate about the vertical axis 23 (Figure 3). It should be noted that the pivot wheel 21 'holds both the rear wheels 19 and the front wheels 17 in an elevated position above the driving plane 25. So if the ground is flat, only the center wheels 15 and the pivot wheel 21 'have ground contact. The front wheels and the rear wheels are thus not a hindrance when turning. The wheels 15, 17, 19 are driven together on one side of the wheelchair. For this purpose, they are coupled together by means of a chain 27 or a toothed belt and corresponding sprockets or gears (not shown). In the same way, a chain 27 or a toothed belt is used to drive the wheels 15, 17, 19 on the other side of the wheelchair. Therefore, two motors are sufficient to drive all wheels. It would also be possible to drive the front wheel pair 17 and the rear wheel pair 19 by a separate motor.

Of importance now is that the pivot wheel 21 ', which holds both the front wheels and the rear wheels normally in an elevated position above the road surface 25 to allow turning in a confined space, is height adjustable. Thus, if the swivel wheel 21 is raised, the rear wheels 19 make contact with the ground. The 2006/000331

Lifting of the apparent in Figure 3 pivot wheel 21 'can be done in various ways. Possible would be z.Bsp. a motor drive. In the illustrated embodiment, the pivot wheel 21 is held by spring force in the position shown. When overcoming an obstacle but forces that move the fork 22 of the pivot wheel about the axis of rotation 31 in the direction of the arrow 33, the rear wheels 19 come into contact with the ground. This is also the case when traveling uphill, as shown in FIG. The center wheels 15 lose in a hill climb to contact pressure. But now that the rear wheels have 19 ground contact, the vehicle is driven by four wheels. The wheelchair thus has the advantages of a four-wheel drive. In snowy or irregular terrain, even the front wheels 17 may even grip.

During a descent, the front wheels are loaded so that they make contact with the road (Fig. 5). Since the front wheels are driven, in turn, the benefits of a four-wheel drive arise.

The wheelchair should not only be able to be turned in a small space and have good handling characteristics, but should also be able to overcome relatively large obstacles, even at relatively low speed. This ability is one of the great advantages of the vehicle according to the invention. FIG. 6 shows the various phases of overcoming an obstacle in the forward movement.

a) The vehicle drives with the driven front wheel, which is normally raised slightly from the ground, to the edge of the obstacle.

b) The vehicle climbs on the obstacle with the driven front wheels.

The rear wheels make contact with the ground and promote the vehicle even if the center wheels should lift off the ground.

c) The vehicle climbs with the driven center wheels on the obstacle. 6 000331

8th

d) The vehicle is now moved forward by both the center wheels and the rear wheels with the rear wheels climbing over the obstacle.

e) The vehicle has overcome the obstacle.

In Figure 7, the overcoming of the obstacle is shown in a reverse drive. The process is the same as previously described with reference to Figure 6 except that the rollers of front and rear wheels are reversed.

The wheelchair according to the embodiment of Figures 8a-c is basically the same design as that according to Figures 1 to 3, but has no • motor drive for the front wheels 17 on. It is thus on one side only the middle wheel 15 and rear wheel 19 by means of a chain 27 and corresponding sprockets 28, 30 coupled together. The same applies to the wheels 15, 19 and sprockets 28, 30 on the other side of the wheelchair. In the illustrated embodiment, the front wheels 17 are formed as swivel wheels. But you can also, for example. shown in Fig. 1, be pivotable, but must then be arranged above the driving plane to allow turning of the wheelchair in a small space.

Also, the wheelchair according to the embodiment of Figures 9a-d is basically the same design as that according to FIGS. 1 to 3, but has instead of a motor drive for the rear wheels 19 such a for the front wheels 17. The rear wheels 19 are formed as swivel wheels to allow turning in a small space. The swivel wheels 19 are advantageously sprung. It is possible to provide only one instead of two swivel wheels. But it would also be possible for the same purpose, the structure according to FIGS. 1 to 3 with the non-pivoting rear wheels 19bebeubt with the swivel wheel 21 '. H2006 / 000331

The wheelchair according to FIGS. 10 to 12, like the wheelchair according to FIGS. 1 to 3, has a spring-mounted swivel wheel 21 'on the rear, but additionally has a spring-loaded swivel wheel 21 in front. This prevents the rear wheels 19 and the front wheels during normal driving 17 alternately make ground contact, so a rocking takes place, which is uncomfortable for the driver. The suspension of the swivel wheels 21, 21 'must be adapted to the weight of the driver so that at obstacles, ramps, etc., the driven front wheels 17 or rear wheels 19 have ground contact. Conveniently, the swivel wheels 21, 21 'have a stop so that they can not run counter to the direction of travel einf.

As FIGS. 10 to 15 show, the swivel wheels 21, 21 'are advantageously designed as twin wheels. This has the advantage that it makes turning easier. Wheelchair users appreciate this. Are advantageous such twin wheels even when approaching an obstacle, because when hitting one of the wheels 24 a

Pivoting stafffindet so that both wheels 24 exceed the obstacle together. As a result, in particular the risk of lifting the tires is avoided.

The swivel wheel 21, 21 'is pivotable about the vertical axis 35. The support 37 has two arms 39. Between these is a joint, z.Bsp. A spring joint 41 of the "ROST A" type (TM) is arranged on each side of the spring joint 41. An arm 43 is mounted at its free end and supports the wheel 24. The arms 43 are counter to the force of the spring joint 41 about the horizontal axis 45 pivotable.

In Fig.15 another embodiment of a pivot wheel 21, 21 'is shown, which has two spring joints 41, 41'. The swivel wheel is pivotable about the vertical axis 35. The support 37 has two arms 39. Between these is the first spring joint 41, z.Bsp. of the type "ROSTA" (TM) Spring joint 41 is connected to a, second spring joint 41 '. On both sides of this second spring joint, an arm 39 'is arranged. The arms 39 'together carry the wheels 24. These wheels 24 are located between the arms 39', but it would be possible to arrange the wheels 24 also on the outside of the arms 39 '. The pivoting wheel formed in this way has two horizontal axes 45, 45 'and thus allows greater deflection.

In summary, the following can be stated: The wheelchair has two center wheels 15, which are separately driven by a motor. To turn in a small space, the center wheels 15 can be driven in opposite directions of rotation. When turning the front wheels 17 and the rear wheels 19 are not a hindrance, because they are held by the pivot wheel 21 at a distance from the ground 25. On each side all three wheels 15, 17, 19 are coupled together by means of a chain 27. When hitting the front wheels on an obstacle of the wheelchair climbs with the driven front wheels 17 on the obstacle. In this case, the fork 22, the pivot wheel 21 is pivoted against the force of a spring about the axis of rotation 31 in the direction of the arrow 33, so that the pivot wheel comes into contact with the ground and drives the wheelchair behind. Without losing its ability to turn, thanks to the all-wheel drive allowed in this way, the wheelchair is able to negotiate relatively high obstacles even when driving slowly (Figures 1 and 3).

Claims

H2006 / 00033111Patentansprüche

1. wheelchair Mittenradantrieb, with two center wheels (15) which are separately driven by a motor, at least one front wheel (17) and at least one rear wheel (19), wherein the rear wheel or the front wheel in a

Located above the driving plane, characterized in that the rear wheel and / or the front wheel is driven by a motor and that at least one pivot wheel (21, 21 ') is provided in the vicinity of the rear wheel and / or the front wheel, which the rear wheel and / or the front wheel is held in an elevated position above the driving plane (25), but is adjustable in height to allow the rear wheel or the front wheel ground contact when overcoming obstacles.

2. Wheelchair according to claim 1, characterized in that both the front wheel (17) and the rear wheel (19) are driven by a motor.

3. Wheelchair according to claim 1 or 2, characterized in that on each side of the wheelchair, a front wheel (17) is provided.

4. Wheelchair according to one of claims 1 to 3, characterized in that on each side of the wheelchair, a rear wheel (19) is provided.

5. Wheelchair according to claim 1, characterized in that on each side of the wheelchair a Mittenrad (15), a front wheel (17) and / or a rear wheel (19) is arranged and that in each case a common drive (27) for the wheels Page is provided.

6. Wheelchair according to claim 5, characterized in that the wheels via an endless chain, an endless toothed belt (27), a gear transmission, a cardan drive or other mechanical solution are coupled.

7. Wheelchair according to one of claims 1 to 6, characterized in that the swivel wheel (21, 21 ') is held by spring force in the normal position, in the front wheel (17) and the rear wheel (19) are in a position above the driving plane (25).

8. Wheelchair according to claim 7, characterized in that the swivel wheel (21) is held by a motor in the normal position.

9. Wheelchair according to one of claims 7 or 8, characterized in that the respective pivoting wheel (21, 21 ') in the middle between the rear wheels (19) and the front wheels (17) is arranged.

10. Wheelchair according to claim 1, 5 or 6, characterized in that on each side of the wheelchair at least one front wheel (17) is provided and that the front wheels are formed as swivel wheels (Fig. 8).

11. Wheelchair, with mid-wheel drive, with two center wheels (15), which are separately motor driven, at least one front wheel (17) and at least one rear wheel (19), wherein the front wheel is in an elevated position above the driving level, characterized in that the front wheel (17) can be driven by a motor and that the rear wheel (19) is designed as a swivel wheel (FIG. 9).

12. A wheelchair according to claim 11, characterized in that the rear wheel (19) is designed as a spring-loaded swivel wheel.

13. Wheelchair according to claim 11 or 12, characterized in that on each

Side of the wheelchair a front wheel (17) is provided.

14. Wheelchair according to one of claims 11 to 13, characterized in that on each side of the wheelchair, a rear wheel (19) is provided.

15. Wheelchair according to one of claims 1 to 14, characterized in that in each case a common drive (27) for the middle wheel (15) and the front wheel (17) is provided. 00331

13

16. A wheelchair according to claim 15, characterized in that the wheels via an endless chain, an endless toothed belt (27), a gear transmission, a cardan drive, another mechanical device or are hydraulically coupled.

17. Wheelchair according to one of claims 1 to 16, characterized in that the swivel wheel (21, 21 ') is designed as a twin wheel.

18. Wheelchair according to one of claims 1 to 17, characterized in that the swivel wheel (21, 21 ') at least one spring joint (41, 41').

19. Wheelchair according to claim 18, characterized in that the swivel wheel (21) has two spring joints (41, 41 ') (FIG. 15).