Traction device for a wheelchair

Abstract

Towing device (2) for a wheelchair (1), with a motor (16) and a battery (17), and a substantially T-shaped handlebar (25), with a control handle (27) for the motor (16), characterized in that it has an adapter (24) for replacing the handlebar (25) with a crank drive (30), which is equipped with a sensor for detecting the crank speed and / or the torque applied to the crank drive.

Description

[0001] The invention relates to a traction device for a wheelchair, with at least one drive wheel which is driven by an electric motor which is supplied by an electric battery, and a substantially T-shaped handlebar with a control handle for the motor.

[0002] Such traction devices are generally known. In particular, they can be attached or coupled to a manual wheelchair as separate traction devices.

[0003] In particular, such a traction device can be attached to and detached from the wheelchair by the user themselves. The wheelchair itself remains unchanged and its properties are fully retained.

[0004] When the power add-on is attached to a standard manual wheelchair, the wheelchair's smaller front wheels are lifted off the ground, creating a three-wheeled vehicle with three large wheels, consisting of the wheelchair's two large wheels and the power add-on's drive wheel. Since such a vehicle with large wheels offers better handling on uneven surfaces than a wheelchair with its small front wheels, this is further enhanced by the power add-on. Obstacles can also be overcome more easily.

[0005] It is also known to provide additional braking systems for downhill and sloped journeys, which act particularly on the drive wheel of the towing vehicle.

[0006] Overall, such a traction device can support the wheelchair user in their mobility, with the aim also being to extend the wheelchair user's radius of action by enabling them to easily and independently cover longer distances.

[0007] To steer the wheelchair equipped with a power add-on, the add-on is connected to a T-shaped handlebar, similar to those commonly found on bicycles. This allows the add-on to be pivoted around a substantially vertical axis relative to the wheelchair frame, thereby changing the direction of travel of the drive wheel and thus the wheelchair itself.

[0008] To control the speed, this handlebar has a control grip on one side of its essentially horizontal handlebar, similar to those found on motorcycles and colloquially known as the "throttle grip".

[0009] A certain disadvantage of such a traction device is that it eliminates the physical activity for the wheelchair user that is associated with normal movement in a wheelchair, where the wheelchair user grasps the hand rings on the wheels of the wheelchair and then moves the wheelchair by pushing or pulling.

[0010] In principle, physical activity is always desirable, as it has positive effects on the health and well-being of a wheelchair user.

[0011] The object of the present invention is therefore to further develop a traction device as mentioned above in such a way that it also enables and supports physical activity for a wheelchair user.

[0012] This problem is solved according to the invention with a pulling device which has an adapter for replacing the handlebar with a crank drive which is equipped with a sensor for detecting the crank actuation, in particular the crank speed and / or the torque applied to the crank drive.

[0013] The invention has the advantage that a traction device, as previously known, which is operated solely by turning a control handle, can now be retrofitted by means of the adapter so that it is controlled by turning a crank on the crank drive. This cranking, as a physical act, activates the wheelchair user, while simultaneously, by detecting the crank speed and / or the torque applied to the crank drive and, if applicable, also the crank direction, a signal is generated that replaces the operation of the control handle.

[0014] At the same time, the adapter, which couples the crank drive to the traction device in a rotationally fixed manner, ensures that when the crank drive is pivoted, the traction device can be pivoted around the essentially vertically oriented axis relative to the wheelchair, just as before with the handlebar, in order to change the direction of travel of the drive wheel and thus of the wheelchair.

[0015] Preferably, the crank drive is provided with a crank axis oriented substantially horizontally and transversely to the direction of travel and has crank handles mounted at cranked ends at both ends of this crank axis. These crank handles can extend substantially parallel to the crank axis or be arranged in a substantially vertical plane.

[0016] In this way, a wheelchair user can operate the crank drive with both arms by grasping the crank handles with both hands and turning them. The bent ends at the two opposite ends of the crank axle can be bent in the same direction or in opposite directions.

[0017] Such a crank drive also makes it possible to straighten a wheelchair user's upper body, correcting the rounded back posture that is extremely detrimental to the spine and respiratory muscles. The upright sitting position promoted by using the crank drive physiologically challenges and strengthens the torso and arm muscles, while simultaneously raising the chest, resulting in better, deeper breathing and improved cardiovascular function. This also helps to counteract secondary conditions such as bronchitis.

[0018] Furthermore, the use of the crank drive also has positive effects on the spine, which is adequately stressed, trained, and thus strengthened throughout the back by engaging the back and abdominal muscles and by improving the alignment of the vertebrae. Well-trained shoulder girdle muscles also enable more upright and comfortable sitting and wheelchair use, and help prevent scoliosis.

[0019] To optimize these effects, the crank drive can be connected to an adjustable resistance. This allows the training effect to be adapted to the individual abilities and / or needs of a wheelchair user.

[0020] Preferably, the adjustable resistor operates electromagnetically. Instead of a conventional eddy current brake, the use of a generator is specifically proposed here. This allows for the additional generation of electricity, which can be used directly or after storage in a battery to power the electric motor.

[0021] In a particularly preferred embodiment of the invention, a braking effect can be exerted on the drive wheel during a rotational movement of the crank drive in the opposite direction to the normal direction of rotation (backward actuation). In this way, braking is achieved similar to that known as a "coaster brake" on conventional bicycles. For this purpose, a control system can be provided which, upon reverse actuation of the crank drive, first activates the generator so that it brakes the electric motor coupled to the drive wheel. With a further reverse actuation, a mechanical brake can additionally be activated on the drive wheel to increase the braking effect.

[0022] In this regard, it is possible, for example, to couple the crank drive with a sensor and a freewheel. The freewheel allows the crank drive to be actuated in one direction when riding forward, while movement in the opposite direction is essentially blocked. Subsequently, the braking effect on the front wheel is modulated depending on the force then applied against the clamping action. The force applied against the clamping action can be varied, for example, by mounting the freewheel in a rubber bushing or by a similar mounting that supports its rotation against a spring.

[0023] The adapter according to the invention, mentioned above, for replacing the handlebar with the crank drive preferably has at least one electrical coupling that is released when the handlebar with the control grip is removed and closed when the crank drive is subsequently attached, and vice versa. This electrical coupling can also have several separate contacts. Such a coupling enables a particularly quick exchange of the handlebar and crank drive. The coupling is designed, in particular, to open or interrupt, or close or establish, electrical connections from the control grip or, alternatively, from the crank drive to and / or from the motor or battery. In principle, the aforementioned electrical connections can also lead to or from a controller that is arranged in the wiring path between the control grip or crank drive on the one hand and the battery and / or motor on the other, and through which control signals are transmitted or generated.

[0024] Similar to the electric coupling, at least one mechanical coupling for a Bowden cable or a hydraulic coupling can be provided in the adapter, either as an alternative or in addition. This allows, in particular, the connection between at least one brake lever located on the handlebars near one of the crank grips and a service brake on the towing device to be disconnected and re-established using a comparable actuating element on the crank drive. The same applies in reverse.

[0025] Integrating these couplings into the adapter facilitates a faster and more reliable change of handlebars and crank drive than if these couplings were provided separately on the towing device.

[0026] Preferably, the adapter is equipped with a brake release element that, in particular, actuates the aforementioned service brake when the adapter is open, so that the pulling device cannot be moved when the adapter is open. This increases the operational safety of the pulling device because it cannot be used without handlebars or a crank drive.

[0027] Further advantages and features of the invention will become apparent from the following description of an exemplary embodiment. This will show Fig. 1 a wheelchair with attached traction device with handlebars, Fig. 2 a wheelchair as in Fig. 1 with alternatively mounted crank drive.

[0028] In the Fig. Figure 1 shows a wheelchair 1 with a traction device 2 according to the invention.

[0029] The wheelchair 1 has a wheelchair frame 3 that terminates at its rear upper end in push handles 4. At its front end, the wheelchair frame 3 transitions into a downwardly angled wheelchair front frame 5, which carries footboards 6 at its lower end. Support tubes 7, which are also angled and carry wheelchair front wheels 8 at their lower ends, are attached to the wheelchair front frame 5.

[0030] Two rear wheels 9, equipped with handrims 10, are mounted on the wheelchair frame 3. These are separated from the seat of the wheelchair by mudguards 11, on which, in the example shown here, a seat cushion 12 rests.

[0031] A wheelchair user sits on the seat cushion 12, with their feet resting on the footboards 6. A handbrake 13, acting on the rear wheels 9, can prevent the wheelchair from moving.

[0032] The wheelchair is usually moved either by a third person grasping and pushing it by the handles 4, or by the wheelchair user grasping the hand rings 10 and turning the rear wheels 9 by pushing them forward or backward, thus propelling the wheelchair.

[0033] In the example shown here, however, a pulling device 2 is mounted on the wheelchair, which is attached to the wheelchair's front frame 5 by means of clamping elements 14. When the pulling device 2 is attached to the wheelchair in this way, the wheelchair's front wheels 8 are lifted off the ground.

[0034] A front or drive wheel 15 on the towing device 2 is responsible for supporting the wheelchair 1 from the front; this wheel is equipped with an electric motor 16, which in the example shown here is designed as a hub motor.

[0035] The rear wheels 9 and the front wheel 15 thus make the wheelchair a tricycle, which, due to its design, has good driving characteristics, especially on uneven surfaces.

[0036] The hub motor 16 mentioned above is powered by an electric battery 17, which can be removed from the pulling device for charging. For this purpose, it is inserted into a bracket 18 mounted on the pulling device 2, which can be combined with a cable holder and, if necessary, also with a control housing.

[0037] The front wheel 15 is mounted in a fork 19, which is held at its upper end in a pivot bearing 20. This pivot bearing 20 is connected to the wheelchair front frame 5 of the wheelchair 1 via side tubes 21 of the towing device 2 or its frame, at the ends of which the clamping elements 14 are located. Furthermore, there is a self-engaging locking element 22 between the pivot bearing 20 and the clamping element 14. This locking element engages when the towing device 2 is attached to the wheelchair frame 3, thus holding the wheelchair front wheels 8 in their position raised from the ground. By releasing this locking element, the wheelchair front wheels can be lowered again, and after opening the clamping element, the towing device 2 can be removed from the wheelchair 1.

[0038] The pivot bearing 20 allows the drive wheel 15 with the motor 16 to pivot relative to the wheelchair frame 3, thus steering the wheelchair driven by the traction device. Above the pivot bearing 20, the traction device extends upwards into a headset or fork tube 23, to which the bracket 18 for the electric battery 17 is also attached. This extension 23 terminates at its upper end in an adapter 24.

[0039] At this point, an essentially T-shaped handlebar 25 is inserted in a torsionally rigid manner, at the upper end of which sits an essentially horizontally extending handlebar, which carries grips 26 and 27 at its ends.

[0040] The handle 27 is designed as a control grip that can be rotated relative to the handlebar, with the axis of rotation lying parallel to the center line of the handlebar. By rotating the control grip, the drive of the hub motor 16 is controlled and thus the speed of the drive wheel 15 is changed.

[0041] Not shown here are brake levers that act hydraulically or via Bowden cables on a front brake, which is also not shown and can be a disc or rim brake.

[0042] For the sake of completeness, it should also be noted that the illustrated traction device is equipped with a light 28. Furthermore, it has support legs 29 to allow the traction device 2 to be stored upright when detached from the wheelchair 1.

[0043] This configuration allows the user of such a wheelchair 1 with traction device 2 to sit relatively upright, which is accompanied by an improvement in posture.

[0044] However, the wheelchair user sits relatively statically in the wheelchair and moves this vehicle only by operating the control handle 27.

[0045] To activate the muscles of a wheelchair user accordingly, the handlebar 25 on the adapter 24 is replaced with one in the Fig. 2 detectable crank drive 30, which is equipped with a sensor for detecting the crank speed and / or the torque applied to a crank 31 of the crank drive 30.

[0046] In the example shown here, the crank 31 can be seen laterally next to the crank drive 30 in the direction of travel, so that when actuated, it moves within a plane that is essentially parallel to the direction of travel. Thus, the actual crank axis 34 is oriented essentially horizontally and transversely to the direction of travel. This is a preferred embodiment, although crank movement in a plane transverse to the direction of travel is also theoretically possible.

[0047] The signal generated by the sensor in the crank drive 30, which detects the crank speed and / or the torque applied to the crank 31 of the crank drive 30, replaces the control signal for the hub motor 16, which is generated by a control handle 27 on a handlebar 25 mounted as an alternative to the crank drive: the faster or more forcefully the crank 31 is turned, the faster or more forcefully the hub motor 16 rotates and the faster the wheelchair 1 travels with the attached power assist device 2. The rotational speed of the hub motor 16 can also be influenced by an assistance level, which, similar to an e-bike, limits the effort required at the crank drive or influences the drive power of the hub motor by means of a corresponding control system.

[0048] The direction of travel of the wheelchair coupled to the towing device is controlled by pivoting the crank drive 30 about the axis of rotation defined by the swivel bearing 20. To ensure reliable operation, the adapter 24 is designed to hold the crank drive 30, which is mounted as an alternative to the handlebar 25, in a rotationally fixed position.

[0049] To transmit the corresponding control signals from the crank drive 30 to the hub motor 16, an electrical coupling is integrated into the adapter 24. This coupling is released when the handlebar 25 is removed along with the control grip 27 and closed when the crank drive 30 is subsequently attached. This is a standard electrical plug / socket connection.

[0050] The connection between adapter 24 and hub motor 16 is designed such that the hub motor 16 can only be operated when the electrical coupling is closed. This prevents unintentional movement of the wheelchair 1 coupled to the towing device 2 without a handlebar 25 or crank drive 30.

[0051] Similarly, in a preferred embodiment, a hydraulic coupling or a Bowden cable coupling can also be integrated into the adapter 24 to open the connection between the handlebars or the crank drive and the front wheel brake when the adapter is released, and to close the connection when the adapter is connected. The front wheel brake is actuated via these couplings either by the aforementioned brake levers on the handlebars 25 or by comparable brake levers integrated into grips 32 located at the ends of the cranks 31.

[0052] An adjustable resistance is integrated into the housing 33 of the crank drive 30. This resistance slows the free rotation of the crank 31 and must be overcome by the wheelchair user through muscular effort. This engages the wheelchair user's muscles and circulatory system, resulting in positive health effects.

[0053] The resistance is preferably generated electromagnetically and is adjustable as needed.

[0054] Furthermore, the crank 31 can be connected to an electric generator integrated into the housing 33 of the crank drive, which generates a current when the crank 31 is operated. This current can be measured and processed by the aforementioned sensor in order to control the speed of the hub motor 16 and also to drive the hub motor 16, possibly only after intermediate storage in the battery 17.

[0055] In principle, so-called handcycles already exist, which, like the traction device described here, can be attached to a wheelchair and in which a crank drive propels the drive wheel. However, these typically use a drive chain, a toothed belt, or a cardan shaft drive to transmit the crank's movement to the drive wheel. Such connecting elements require complex routing to avoid running into or through the wheelchair user's movement area. Furthermore, additional protective measures are necessary with such connecting elements to prevent contact, which can lead to injuries and / or soiling.

[0056] A significant advantage of the present invention is therefore that such a handbike is possible by converting a purely electric drive unit as described here, so that a wheelchair coupled to it can be used both passively and in a way that activates the wheelchair user. Reference symbol list 1 wheelchair 2 Traction device 3 wheelchair frames 4 push handles 5 wheelchair front frames 6 running boards 7 Carrier tube 8 wheelchair front wheels 9 rear wheels 10 grab rings 11 mudguards 12 seat cushions 13 Handbrake 14 clamping elements 15 drive wheel 16 engine 17 electric battery 18 bracket 19 Fork 20 Rotary bearing 21 side tube 22 Locking element 23 Headset or fork tube 24 adapters 25 handlebars 26 handle 27 Rotary handle 28 Lighting 29 support legs 30 Crank drive 31 crank 32 handles 33 cases 34 Crank axle

Claims

[1] Towing device (2) for a wheelchair (1), comprising a motor (16) and a battery (17), and a substantially T-shaped handlebar (25), comprising a control handle (27) for the motor (16), characterized by , that it has an adapter (24) for replacing the handlebar (25) with a crank drive (30) which is equipped with a sensor for detecting the crank speed and / or the torque applied to the crank drive. [2] Traction device according to claim 1, characterized by , that the crank drive (30) is provided with a crank axis (34) oriented essentially horizontally and transversely to a direction of travel and carries crank handles (32) mounted at cranked ends at both ends of the crank axis (34). [3] Traction device according to one of the preceding claims, characterized by , that the crank drive (30) is connected to an adjustable resistance. [4] Traction device according to claim 3 characterized bythat the adjustable resistor is electromagnetic. [5] Traction device according to one of the preceding claims, characterized by , the adapter (24) has an electrical coupling which is released when the handlebar (25) is removed with the control grip (27) and closed when the crank drive (30) is subsequently attached. [6] Traction device according to one of the preceding claims, characterized by , that the adapter (24) has a hydraulic coupling which is released when the handlebar (25) is removed with the control grip (27) and closed when the crank drive (30) is subsequently attached. [7] Traction device according to one of the preceding claims, characterized by , that the adapter (24) has a mechanical coupling for a Bowden cable, which is released when the handlebar (25) is removed with the control grip (27) and closed when the crank drive (30) is subsequently attached. [8] Traction device according to one of the preceding claims, characterized by, that the adapter (24) is provided with a brake release element which actuates a service brake when the adapter (24) is open.

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