US-12622827-B2 - Muscle-powered wheelchair and method for controlling an auxiliary drive for same

US12622827B2US 12622827 B2US12622827 B2US 12622827B2US-12622827-B2

Abstract

A wheelchair having at least one force element that is elastically deformable, wherein deformation of the at least one force element becomes more and more intense with the application of increasing force, resulting in natural damping of the coupled-in force, which may be detected by a sensor such that the wheelchair according to the invention may be controlled in a targeted manner for fine movements as well as for faster, coarser movements.

Inventors

Harald Kauffmann
Thomas Birmanns

Assignees

Motion Advantage Verwaltungs-GmbH

Dates

Publication Date: 20260512
Application Date: 20230920
Priority Date: 20220923

Claims (16)

1 . A wheelchair comprising: at least one drive wheel ( 4 ), wherein the at least one drive wheel ( 4 ) comprises a wheel rim ( 5 ); an electrical drive means ( 3 ) connected to the at least one drive wheel ( 4 ) and configured to selectively rotate the at least one drive wheel ( 4 ) in response to a travel signal; at least one elastically deformable push rim ( 8 ) mounted to the wheel rim ( 5 ) by at least two connecting elements ( 9 ) distributed about the circumference of the at least one drive wheel ( 4 ), wherein each of the at least two connecting elements ( 9 ) comprises a longitudinal axis extending between the location at which each of the at least two connecting elements ( 9 ) is mounted to the at least one push rim ( 8 ) and the location at which each of the at least two connecting elements ( 9 ) is mounted to the wheel rim ( 5 ), and further wherein at least one of the at least two connecting elements comprises a signal generator ( 10 ); wherein each of the at least two connecting elements ( 9 ) is configured to pivot about at least one pivot bearing upon the deformation of the at least one push rim ( 8 ) resulting from the application of force to the at least one push rim ( 8 ) in a direction generally perpendicular to the longitudinal axis of the at least two connecting elements; wherein the signal generator is configured to generate a travel signal corresponding to the degree of deformation of the at least one push rim where the at least one push rim is mounted to the at least two connecting elements ( 9 ); and wherein the travel signal is transmitted to a control unit ( 15 ), and further wherein the control unit ( 15 ) activates the electrical drive means ( 3 ) so as to selectively rotate the at least one drive wheel ( 4 ).
2 . The wheelchair according to claim 1 , wherein each of the connecting elements ( 9 ) are articulatedly connected to (i) the wheel rim ( 5 ) by means of a first pivot bearing ( 11 ), and (ii) to the at least one push rim ( 8 ) by means of a second pivot bearing ( 12 ).
3 . The wheelchair according to claim 2 , wherein at least one of the first pivot bearing ( 11 ) and/or the second pivot bearing ( 12 ) comprises a roller bearing.
4 . The wheelchair according to claim 1 , wherein the at least two connecting elements ( 9 ) are connected to the at least one push rim ( 8 ) by means of a push rim bracket ( 7 ) that points radially inwardly or outwardly from the push rim ( 8 ), or are connected to the wheel rim ( 5 ) by means of a bearing point ( 6 ) that points radially outwardly or inwardly from the wheel rim ( 5 ).
5 . The wheelchair according to claim 1 , wherein the signal generator ( 10 ) is a Hall probe ( 13 ) which is situated at the wheel rim ( 5 ) or at the push rim ( 8 ) and faces a connecting element ( 9 ), and which detects a movement of a magnet ( 14 ) situated at this connecting element ( 9 ).
6 . The wheelchair according to claim 1 , characterized in that the signal generator ( 10 ) comprises a bending beam and a strain gauge.
7 . The wheelchair according to claim 1 , wherein the signal generator ( 10 ) comprises at least one selected from the group consisting of a magnetostrictive sensor, a magnetoresistive sensor, an inductive sensor, and an optical sensor.
8 . A wheelchair comprising: at least one drive wheel ( 4 ), wherein the at least one drive wheel comprises a wheel rim ( 5 ); an electrical drive means ( 3 ) connected to the at least one drive wheel ( 4 ) and configured to selectively rotate the at least one drive wheel ( 4 ) in response to a travel signal; at least one elastically deformable push rim ( 8 ) mounted to the wheel rim ( 5 ) by at least two connecting elements ( 9 ) distributed about the circumference of the at least one drive wheel ( 4 ); wherein each of the at least two connecting elements ( 9 ) comprises a longitudinal axis extending between the location at which each of the at least two connecting elements ( 9 ) is mounted to the at least one push rim ( 8 ) and the location at which each of the at least two connecting elements ( 9 ) is mounted to the wheel rim ( 5 ), and further wherein at least one of the at least two connecting elements comprises a signal generator ( 10 ); wherein at least one of the at least two connecting elements ( 9 ) comprises an elastically deformable force element, and further wherein the signal generator is configured to detect elastic deformation of the force element along the longitudinal axis of the connecting element, and to generate a travel signal corresponding to the degree of deformation of the force elements; wherein the travel signal is transmitted to a control unit ( 15 ), and further wherein the control unit ( 15 ) activates the electrical drive means ( 3 ) so as to selectively rotate the at least one drive wheel ( 4 ).
9 . The wheelchair according to claim 8 , wherein each of the connecting elements ( 9 ) are articulatedly connected to (i) the wheel rim ( 5 ) by means of a first pivot bearing ( 11 ), and (ii) to the push rim ( 8 ) by means of a second pivot bearing ( 12 ).
10 . The wheelchair according to claim 9 , wherein at least one of the first pivot bearing ( 11 ) and the second pivot bearing ( 12 ) comprises a roller bearing.
11 . A method for controlling an auxiliary drive for a wheelchair comprising: providing a wheelchair ( 1 ) comprising: at least one drive wheel ( 4 ), wherein the at least one drive wheel ( 4 ) comprises a wheel rim ( 5 ); an electrical drive means ( 3 ) connected to the at least one drive wheel ( 4 ) and configured to selectively rotate the at least one drive wheel ( 4 ) in response to a travel signal; at least one elastically deformable and push rim ( 8 ) mounted to the wheel rim ( 5 ) by at least two connecting elements ( 9 ) distributed about the circumference of the at least one drive wheel; wherein each of the at least two connecting elements ( 9 ) comprises a longitudinal axis extending between the location at which each of the at least two connecting elements ( 9 ) is mounted to the at least one push rim ( 8 ) and the location at which each of the at least two connecting elements ( 9 ) is mounted to the wheel rim ( 5 ), and further wherein at least one of the at least two connecting elements comprises a signal generator ( 10 ); wherein each of the at least two connecting elements ( 9 ) is configured to pivot about at least one pivot bearing upon the deformation of the at least one push rim ( 8 ) resulting from the application of force to the at least one push rim ( 8 ) in a direction generally perpendicular to the longitudinal axis of the at least two connecting elements; wherein the signal generator ( 10 ) is configured to generate a travel signal corresponding to the elastic deformation of the at least one push rim where the at least one push rim is mounted to the at least two connecting elements ( 9 ); transmitting the travel signals generated by the signal generator ( 10 ) to a control unit ( 15 ) to control the electrical drive means ( 3 ); and activating the electrical drive means ( 3 ) by the control unit ( 15 ), whereby to rotate the at least one drive wheel ( 4 ).
12 . The method according to claim 11 , wherein the the wheel rim ( 5 ) is deformable, and further wherein deformation of the wheel rim ( 5 ) applies force to the plurality of connecting elements ( 9 ).
13 . The method according to claim 12 , wherein a deflection, in the same direction, of the plurality of connecting elements ( 9 ) is converted by the control unit ( 15 ) into a travel signal in the rotational direction of the deflection.
14 . The method according to claim 13 , wherein the travel signal corresponds to the degree of deflection of the connecting element ( 9 ).
15 . The method according to claim 13 , wherein a deflection, in an opposite direction, of the plurality of connecting elements ( 9 ) is converted by the control unit ( 15 ) into a control signal.
16 . A method for controlling an auxiliary drive for a wheelchair, the method comprising: providing a wheelchair ( 1 ) comprising: at least one drive wheel ( 4 ), wherein the at least one drive wheel comprises a wheel rim ( 5 ); an electrical drive means ( 3 ) connected to the at least one drive wheel ( 4 ) and configured to selectively rotate the at least one drive wheel ( 4 ) in response to a travel signal; at least one elastically deformable push rim ( 8 ) mounted to the wheel rim ( 5 ) by at least two connecting elements ( 9 ) distributed about the circumference of the wheel rim ( 5 ); wherein each of the at least two connecting elements ( 9 ) comprises a longitudinal axis extending between the location at which each of the at least two connecting elements ( 9 ) is mounted to the at least one push rim ( 8 ) and the location at which each of the at least two connecting elements ( 9 ) is mounted to the wheel rim ( 5 ), and further wherein at least one of the at least two connecting elements comprises a signal generator ( 10 ); wherein at least one of the at least two connecting elements ( 9 ) comprises an elastically deformable force element, and further wherein the signal generator is configured to detect elastic deformation of the force element along the longitudinal axis of the connecting element, and to generate a travel signal corresponding to the degree of deformation of the force element; transmitting the travel signals generated by the signal generator ( 10 ) to a control unit ( 15 ) to control the electrical drive means ( 3 ) and activating the electrical drive means ( 3 ) by the control unit ( 15 ), whereby to rotate the at least one drive wheel ( 4 ).

Description

REFERENCE TO PENDING PRIOR PATENT APPLICATION This patent application claims benefit of German Patent Application No. 10 2022 124 524.1, filed Sep. 23, 2022, which patent application is hereby incorporated herein by reference. FIELD OF THE INVENTION The present invention relates to a muscle-powered wheelchair with an auxiliary drive, comprising two drive wheels with wheel rims and electrical drive means, a push rim being associated with each of the wheel rims by means of at least two connecting elements that are distributed over the circumference of the drive wheels, and to a method for controlling an auxiliary drive for same. BACKGROUND OF THE INVENTION Such a wheelchair is previously known from the disclosure of DE 198 48 530 C1. This wheelchair is based on a concentric push rim bearing, situated at the wheel circumference, and a sensor element with spring pretensioning that holds the sensor in a neutral position. When a user pushes the push rim forward, for example, the push rim moves in relation to the wheel rim, while the suspension of the push rim detects the associated direction. The connecting element goes into an inclined position, thereby triggering a switch that initiates a drive of the wheelchair for forward travel. Other systems have a support of the push rim in the center of the wheel, i.e., in the hub motor. One design is described in DE 697 19 432 T2. The push rim is fastened at the inside to a rotatable disk by means of three spoke-like struts. This rotatable disk is elastically supported on the hub body via springs. Further prior art is already known from DE 20 2016 100 975 U1 and EP 0 995 415 A2. A first problem of previously known designs is that for the force-related deflection of the push rim, spring pretensioning of the push rim bearing must initially be overcome before a measuring signal is generated, which results in a travel signal at the drive. This spring pretensioning may be fairly high, depending on the design. Most approaches use a less precise bearing of the push rim, since this bearing must withstand all typical loads on a wheelchair. In particular radial and axial shocks and impacts on the push rim may occur, for example when traveling against an obstacle or when the wheel, removed from the wheelchair, falls off during loading into an automobile. This robustness is usually recovered using a bearing which is designed for such a load and which is correspondingly tight. In turn, resetting and centering such a tight bearing may be achieved only with appropriately great spring pretensioning. A second problem results for the case that spring pretensioning that is greater on one side preferentially pretensions the push rim more intensely in a first direction than in a second direction. As a result, equal forces that are introduced by the user may result in travel signals of different intensities, depending on whether they are generated in the first rotational direction or in the second rotational direction. This may have undesirable effects for use of the wheelchair, in particular when the wheelchair has two identical wheels that may be mounted on the left side or also on the right side of the wheelchair, and these wheels are mounted on the wheelchair with different pretensioning on the left side than on the right side. Thus, merely becoming acclimated to this error is not possible. A third problem is the deflection of the push rim against a hard stop. After the spring pretensioning is overcome, a brief deflection in the active sensor field occurs, which is usually followed by a hard stop of the push rim at the maximum deflection. This results in an undefined haptic sensation for the wheelchair rider, which leads to uncertainty and makes it difficult to generate an appropriately metered signal generation. Some of the previously known approaches have attempted to eliminate this by use of so-called flexible mechanisms. A flexible mechanism is a mechanism that achieves a transfer of force and movement by elastic body deformation. This mechanism gains all or part of the movement from mutual flexibility of its members, and not just from the movement of rigid body joints. Such a mechanism, which combines multiple parallel spring elements to form a flexible mechanism, is known form EP 2 277 487 Bl. These spring elements are mounted at the circumference of the wheel rim of the wheelchair wheel in various designs, and are thus intended to bring about a rotational movement, and at the same time a concentric movement, of the push rim. However, the problem here is that each of these flexible mechanisms acts as an individual spring. Thus, the introduced force is not redirected into a concentric movement, but instead, is only diverted to the next flexible element due to the overall flexibility of the wheelchair wheel and the push rim. From there, the force is distributed over the entire system and results in deformation of the system, and results less in the targeted concentric deflection of th