WHEELCHAIR

Description

[0001] The invention relates to a wheelchair having a frame with a plurality of frame sections on which a seat and two drive wheels are arranged, and at least one motor for driving the drive wheels.

[0002] Such a wheelchair is known, for example, from US 9 039 018 B1.

[0003] Motorized wheelchairs have long been known in the art of mobility. They allow people with physical disabilities and limited mobility to move around virtually freely without excessive physical exertion or requiring assistance from another person. People who must use wheelchairs typically spend a large portion of their day in them, so it's very important that the wheelchair provides a high level of comfort and a sense of security.

[0004] Particularly with regard to comfort, a number of different suggestions for improvement have been made in the prior art, and different wheelchairs have been developed. Especially for movements on uneven terrain, it is advantageous to absorb and cushion shocks that can be transmitted to the wheelchair as it moves over the terrain, thus resulting in a pleasant, smooth, and comfortable ride for the wheelchair user. WO 2016 / 059656 A1, for example, discloses a wheelchair which has a sprung seat to absorb such shocks. The seat, which may comprise a cushion, for example, is mounted on a flat spring which is compressed when the wheelchair user sits down. Care must be taken not to compress the spring completely, as this would reduce or completely reduce its spring effect.

[0005] FR 2 850 013 A1, however, proposes a different suspension. The wheelchair frame essentially consists of a plate-shaped element bent into a U-shape. The two legs of the U extend rearward in the direction of travel of the wheelchair and are connected at the front by the bend in the U. While the seat is in an inclined position on the upper leg, the drive wheels are located on the lower leg of the curved plate.

[0006] Even though these and other spring mechanisms known from the prior art can absorb and cushion shocks and impacts transmitted from the ground to the wheelchair's chassis or frame, these designs have the disadvantage that, particularly on uneven terrain or when negotiating steps such as curbs, there is a risk of tipping. This is caused in particular by the fact that in certain situations, inclines, and directions of travel, not all of the wheelchair's wheels are in contact with the ground. This leads to a feeling of insecurity and thus to a reduction in confidence in the wheelchair, which is, however, necessary for the desired feeling of security that the wheelchair user should have.

[0007] US 2005 / 0127631 A1 and US 7,234,554 B2 each describe a wheelchair in which the driven axles are individually suspended and sprung with a coil spring. A similar design is also known from US 7,766,106 B2 or US 2004 / 0084230 A1. CA 2 254 372 A1 takes the opposite approach and provides a spring for the non-driven wheels. US 5,518,081 proposes using air suspension instead of the coil spring.

[0008] In the publications US6,234,507 B1 and US9,039,018 B1, the wheelchair frame is formed from interlocking tubular elements, each with a square cross-section, for example. The edge lengths of the cross-sections of the tubes to be connected vary considerably, so the respective cross-sections are offset from each other, for example, by 45°. The resulting gaps are filled with buffers made of elastic material. This allows the two tubular elements to be pivoted elastically against each other, resulting in a certain spring effect.

[0009] The disadvantage of all these designs is the relatively high weight of the spring arrangement, which results in high energy consumption and difficulty in handling.

[0010] The invention is therefore based on the object of further developing a wheelchair in such a way that the disadvantages of the prior art are eliminated or at least mitigated.

[0011] The invention solves the stated problem by a wheelchair according to the preamble of claim 1, which is characterized in that the drive wheels are each arranged on a resilient frame section so that they are sprung independently of one another, wherein the frame is open on one side and has at least one substantially U-shaped, V-shaped, or C-shaped frame element, each with an upper bar on which the seat surface is located, and a lower bar that forms the resilient frame section. This makes it possible to compress or use the changes of the individual drive wheels to different degrees in different inclinations or positions of the wheelchair, and thus to maintain ground contact, in particular of the two drive wheels, in almost every situation, but preferably in all situations.

[0012] For this purpose, the drive wheels are initially mounted independently of one another. Unlike in the prior art, in which the two drive wheels are each connected to one another via a component that is rigid in the connection direction, with the wheelchair according to the invention it is possible to move the two drive wheels via the respective suspension to different degrees, different distances and possibly even in different directions relative to the seat on which the wheelchair user sits when the wheelchair is in operation. Each of the drive wheels is arranged on a frame section and rotatably fastened thereto. The frame section can itself be spring-loaded, for example in the form of a leaf spring, in particular made of a composite material, in particular a carbon fiber composite material. Alternatively or additionally, the respective frame section can also be spring-mounted, in particular fastened to another frame section.This can be achieved, for example, by attaching the spring-mounted frame section to the other frame element via a joint, with the movement enabled by the joint being damped by a damper. It is important that when the drive wheel and / or the frame section to which it is attached is deflected, a restoring force is generated that moves the wheel back to its original position. Of course, a combination of a spring-mounted mounting and a spring-loaded frame section is also possible and may be advantageous.

[0013] Preferably, the wheelchair has two motors, each of which can be used to drive a drive wheel. One of the motors is mounted on each of the spring-loaded frame sections.

[0014] The frame sections, each on which a drive wheel is arranged, are preferably struts, tubes or rods that project rearward in the direction of travel. The drive wheel is particularly preferably arranged in the rear region of these. Alternatively, the frame sections, each on which a drive wheel is arranged, are struts, tubes or rods that project forward in the direction of travel. The drive wheel is particularly preferably arranged in the front region of these. This frame section is preferably designed with a rotationally symmetrical, for example circular, cross-section in order to ensure the best possible suspension in different directions, for example up and down and to the right and left. Alternatively, it is also possible for the cross-section to have n-fold rotational symmetry, where n is, for example, 4, 6 or 8. The cross-section is preferably polygonal, for example a square, hexagon or octagon.An oval cross-section can also be used. It is not necessary for the cross-section to be constant across the length of the frame section. A change in the cross-section can also be advantageous.

[0015] The wheelchair preferably has at least one damping element that is arranged and configured to dampen a resilient movement of the frame section in at least one direction. A resilient movement is generally an oscillating movement, i.e. a back-and-forth movement. In the present case, damping in at least one direction is understood in particular to mean damping that dampens such a resilient movement during both the back-and-forth movement. If a resilient movement runs up and down, for example, this is a resilient movement in one direction within the meaning of the present invention. If this resilient movement is dampened in one direction, both the back-and-forth movement, for example upwards, and the back-and-forth movement, in this example downwards, are dampened.

[0016] Preferably, the frame has a fastening area arranged at the front in the direction of travel, in which or through which the resilient frame sections are connected to one another and / or to other elements of the frame. Particularly preferably, these frame sections extend from this fastening area to the rear of the wheelchair in the direction of travel.

[0017] The attachment area preferably comprises a frame element extending transversely to the direction of travel, which is particularly designed in the form of a strut, a tube, or a rod. The resilient frame sections are preferably arranged at the ends of this frame element. The frame element thus connects the two frame sections to one another and, in particularly preferred embodiments, thus ensures the necessary stability of the wheelchair and its frame. In a preferred embodiment, the different frame sections are connected to one another exclusively in the area of ​​the attachment area.

[0018] Preferably, the at least one motor is an electric motor. This is generally supplied with electrical current and electrical energy by at least one battery so that the motor can drive the drive wheels. This battery must be carried with the wheelchair, for which purpose a holder is preferably provided. In a particularly preferred embodiment, this holder is arranged on the fastening area of ​​the frame and fastened thereto. Preferably, it is located between the resilient wheel sections. This ensures that the usually heavy component of the battery is arranged as low as possible in the wheelchair, so that the center of gravity of the wheelchair is as low as possible in order to achieve increased stability.

[0019] Advantageously, a footrest is arranged in the fastening area. Particularly preferably, the holder for the battery and / or the footrest and / or a control module and / or a container positioned between the two spring-loaded or spring-mounted frame sections is mounted exclusively on or in the fastening area and preferably has no direct connection to one of the spring-loaded or spring-mounted frame sections. Particularly preferably, the components are mounted exclusively on a frame element running transversely to the direction of travel. Since they have no further connection to the spring-loaded frame section on which at least one of the drive wheels is located, they do not impair the spring action, so that the desired effect is fully achieved.

[0020] According to the invention, the frame is open on one side. It has at least one, preferably two substantially U-shaped, V-shaped or C-shaped frame elements, each having an upper bar on which the seat surface is located, and a lower bar that forms the resilient frame section. The upper bars of the two substantially U-shaped, V-shaped or C-shaped frame elements can, but do not have to, be connected to one another by other elements of the wheelchair, for example the seat surface or a backrest. Preferably, the lower spaces are only connected to one another in the region of the fastening area and are otherwise not restricted in their flexibility and resilient properties by any further connection to other components.

[0021] This also includes frames which, for example, have a guide which restricts movement of the ends of the bars relative to one another in one direction or to one direction. In the context of the present invention, a movement in one direction is also understood to mean a resilient, i.e. oscillating, movement in this direction, for example a back and forth movement up and down. An oscillating movement to the right and left is also understood here as a movement in one direction. A guide is preferably designed to be completely contactless or almost contactless, so that two guide elements which are arranged on the bars and whose movement relative to one another is to be guided do not touch as long as the movement of the two bars occurs along the guide direction. Contact only occurs when there is movement outside of this direction, thus restricting the possible movements.This can be achieved, for example, by using tubes arranged telescopically within one another, whose longitudinal axes are preferably identical. The tubes are thus arranged concentrically to one another and have different diameters, allowing them to be inserted into one another. This type of guide allows movement along the common longitudinal direction of the tubes.

[0022] Additionally or alternatively, at least one damping element is preferably arranged between two bars. It can be arranged between the two upper bars, the two lower bars, or an upper and a lower bar. In the latter case, the two bars are preferably, but not necessarily, arranged on the same side of the wheelchair, i.e., to the right or left in the direction of travel. A damping element between an upper and a lower bar, which are not arranged on the same side of the wheelchair, can also be advantageous. Such a spring element is, for example, a damper, a spring damper, or an elastic element.

[0023] Alternatively or additionally, a damping element is preferably arranged on only one spar. This damping element is, for example, a leaf spring or a leaf spring stack arranged parallel to the spar and preferably on the spar.

[0024] Preferably, a support element is arranged on the frame section behind the drive wheels in the direction of travel, which prevents the wheelchair from tipping backwards.

[0025] An exemplary embodiment of the present invention is explained in more detail below with the aid of the accompanying figures. They show: Figures 1 to 5 - a wheelchair according to a first embodiment of the present invention in different assembly stages and Figures 6 to 10 - detailed views of components for wheelchairs according to embodiments of the present invention.

[0026] Figure 1 shows a wheelchair 1 according to a first embodiment of the present invention. It has drive wheels 2, one of which Figure 1only 1 is shown, as well as steering wheels 4. The wheels 2, 4 are arranged on a frame 6 which supports a seat 8. The frame 6 has two frame elements 10 which are essentially U-shaped and each have an upper bar 12 to which the seat 8 is attached, and a lower bar 14. The drive wheels 2 are attached to the respective lower bars 12 and 14. At the front in the direction of travel, between the two frame elements 10, there is a frame element 16 which runs transversely to the direction of travel and forms the attachment area. It connects the two U-shaped frame elements 10 to one another and also supports a footrest 18. Between the two frame elements 10 there are containers 20 which contain batteries which supply power to motors 22 which drive the drive wheels 2.

[0027] Figure 2 shows the wheelchair 1 in a slightly disassembled state. Compared to Figure 1the seat surface 10 and the wheels 2, 4 are missing. This makes it easier to see that the frame element 10 has an upper bar 12 and a lower bar 14, on which there is a wheel suspension 24 to which a drive wheel 2 can be attached. It is driven by the motor 22 and is supplied with electrical energy by a battery 26. The battery 26 is mounted in a holder 28 which is attached to the frame element 16 running transversely to the direction of travel. This also carries the footrest 18. In addition to the upper bar 12 and the lower bar 14, the frame element 10 has a curved section 30 which connects the two bars 12, 14 to one another. In the exemplary embodiment shown, the frame elements 10 are designed as metal tubes which have an inherently springy effect.This effect is reinforced by the curved section 30, so that the lower beam 14 is both a spring-loaded frame section and a spring-loaded frame section.

[0028] Figure 3shows wheelchair 1 in a further disassembled representation in a side view. The footrest 18 and the holder 28 for the battery 26 (no longer shown) are arranged exclusively on the frame element 16 running transversely to the direction of travel and have no other connection to the frame element 10. The curved section 30 connects the upper bar 12 to the lower bar 14 and provides a large part of the required elasticity and suspension. The wheel suspension 24 is provided for one of the drive wheels 2. At the rear end of the lower bar 14 in the direction of travel there is a support element 32, at the lower end of which a small support wheel can be arranged. Such elements are known from the prior art and serve, for example, to prevent the wheelchair 1 from tipping backwards.

[0029] Figure 4shows the frame 6 of a wheelchair 1 with footrest 18 and bracket 28 arranged thereon. In this illustration, in which the wheelchair 1 has been further disassembled, the two upper bars 12 with the seat surface arranged between them, of which in Figure 4 Only the support 34 is shown, which is clearly visible. Both upper beams 12 are each connected to a lower beam 14 by an arc section 30. The two lower beams 14 have no contact or connection with each other except for the frame element 16, which runs transversely to the direction of travel. This frame element, as in the other figures, also supports the footrest 18 and the bracket 28.

[0030] Figure 5 shows only the frame 6 of a wheelchair with the two upper bars 12, the two lower bars 14, the two curved sections 30 and the frame element 16 running transversely to the direction of travel. While in Figure 5Although the individual U-shaped frame elements 10 are shown as integrally formed, this is possible and may be advantageous, but not necessary. The individual frame sections 12, 14, 30, 32 can also be formed as separate elements that are connected to one another, for example, by gluing or welding.

[0031] Figure 6 shows one of the frame elements 10 in a side view, wherein a spring element 36 is arranged between the upper beam 12 and the lower beam 14. In Figure 7A spring-damper element 38 is arranged between the upper beam 12 and the lower beam 14, which is shown schematically. It has a spring element 36 and a damping element 40 arranged parallel to it. Even though the spring element 36 and the spring-damper element 38 are arranged in Figures 6 and 7 between an upper beam 12 and a lower beam 14, which belong to the same frame element 10, this is advantageous but not necessary. A spring element 36 or a spring-damper element 38 can also be arranged between two upper beams 12, between two lower beams 14, or between an upper beam 12 and a lower beam 14 that do not belong to the same frame element 10.

[0032] Figure 8shows the frame element 10, in which a guide 42 is arranged between the upper beam 12 and the lower beam 14. In the illustrated embodiment, this limits the movement of the upper beam 12 relative to the lower beam 14 to a movement in the vertical direction, i.e., upwards and downwards. Both upward and downward movements are possible and are meant by the described formulation. As shown in the Figures 6 and 7 is also in Figure 8 merely a schematic representation of the element arranged between the beams 12, 14 is shown. The illustration makes no statement about the actual design of a spring element 36, a spring-damper element 38, a damping element 40, or a guide 42.

[0033] In Figure 9A damping element 40 is arranged on the lower beam 14 of the frame element 10. In the illustrated embodiment, the damping element 40 comprises three leaf springs 44 that rest on one another. The lowest leaf spring 40 shown rests almost completely, but preferably completely, against the lower beam 14. If the lower beam 14 is then subjected to a resilient movement, for example, deflected upwards or downwards, the leaf springs 44 must also be deflected accordingly. This creates friction between the individual leaf springs 44, which creates the damping.

[0034] In Figure 10 two frame elements 10 are shown, as shown in Figure 5 In contrast to the illustration in Figure 5A connection 46 is arranged between the two lower beams 14, which, for example, increases torsional rigidity. This influences the spring properties and freedom of movement of the individual beams 12, 14 and thus also of a seat surface arranged on the upper beams 12. List of reference symbols

[0035] 1 Wheelchair 2 Drive wheel 4 Steering wheel 6 Frame 8 Seat 10 Frame element 12 Upper bar 14 Lower bar 16 Frame element 18 Footrest 20 Container 22 Motor 24 Wheel suspension 26 Battery 28 Bracket 30 Curved section 32 Support element 34 Carrier 36 Spring element 38 Spring-damper element 40 Damping element 42 Guide 44 Leaf spring 46 Connection

Claims

1. A wheelchair (1) comprising a frame (6) with multiple frame sections, on which a seat surface (8) and two drive wheels (2) are arranged, and at least one motor (22) for driving the drive wheels (2), characterised in that each drive wheel (2) is arranged on one spring-mounted frame section (14) such that they are spring-mounted independently of each other, wherein the frame (6) is open on one side and comprises a largely u-shaped, v-shaped or c-shaped frame element (10), each with an upper bar (12) where the seat surface (8) is located, and each with a lower bar (14) that forms the spring-mounted frame section (14).

2. The wheelchair (1) according to claim 1, characterised in that the wheelchair (1) comprises two motors (22) for driving one drive wheel each (2), wherein preferably, one motor (22) is arranged on one of the spring-mounted frame sections (14), respectively.

3. The wheelchair (1) according to claim 1 or 2, characterised in that the frame sections (14), one drive wheel (2) being arranged on each one, are struts, tubes or bars that protrude backwards in the direction of travel, the drive wheel (2) in each case being arranged in the rear area, or that the frame sections (14), one drive wheel (2) being arranged on each one, are struts, tubes or bars that protrude forwards in the direction of travel, the drive wheel (2) in each case being arranged in the front area.

4. The wheelchair (1) according to one of the preceding claims, characterised in that the wheelchair (1) comprises a damping element that is arranged and configured to damp a spring movement of the frame section (14) in at least one direction.

5. The wheelchair (1) according to one of the preceding claims, characterised in that the frame (6) comprises an attachment area arranged at the front in the direction of travel in which or via which the spring-mounted frame sections (14) are connected to each other and / or to other elements of the frame.

6. The wheelchair (1) according to claim 3, characterised in that the attachment area comprises a frame element (16) extending transversely to the direction of travel, in particular in the form of a strut, a tube or a bar, at the ends of which the spring-mounted frame sections (14) are arranged.

7. The wheelchair (1) according to claim 3 or 4, characterised in that the at least one motor (22) is an electric motor and a mount (28) for a battery (26) is arranged on the attachment area of the frame (6), preferably between the spring-mounted frame sections (14).

8. The wheelchair (1) according to one of the claims 3 to 5, characterised in that a footrest (18) is arranged on the attachment area.

9. The wheelchair (1) according to one of the claims 3 to 6, characterised in that the mount (28) for the battery (26) and / or the foot rest (18) and / or a container (20) positioned between the two spring-mounted frame sections (14) is mounted exclusively on or in the attachment area and preferably has no direct connection to one of the spring-mounted and / or spring-loaded frame sections (14).

10. The wheelchair (1) according to one of the preceding claims, characterised in that two largely u-shaped, v-shaped or c-shaped frame elements (10), each with an upper bar (12) where the seat surface (8) is located, and a lower bar (14), which forms the spring-mounted frame section (14).

11. The wheelchair (1) according to one of the preceding claims, characterised in that a support element (32) is arranged on the frame section (14) behind the drive wheels (2) in the direction of travel, which prevents the wheelchair (1) from tipping backwards.