Patent Publication Number: US-2022236760-A1

Title: Joystick with Adjustable Operating Force for Electrical Wheelchair Devices

Description:
BACKGROUND 
     Technical Field 
     The example and non-limiting embodiments disclosed herein relate generally to electrically-powered wheelchairs and, more particularly, to joysticks for controlling electrically-powered wheelchairs. 
     Brief Description of Prior Developments 
     Powered personal mobility vehicles, such as electrically-powered wheelchairs having self-contained power sources that provide drive power to wheels and steering actuators, may include various user interface systems to control the drive power and motive subsystems of the vehicles. These user interface systems allow a user to interact with the vehicle through an input device to execute start, stop, and steer functions. 
     Users with varying degrees of disability may desire the input device to be in the form of a joystick or similar type of hand control. For users of electric wheelchairs, it is desirable to have the option of adapting the operating force of the joystick to their ability. To adapt the operating force of the joystick in a current wheelchair, a spring that is provided with the joystick may need to be replaced, with the replacement spring being selected to match the user&#39;s hand mobility/strength. However, a suitable replacement spring that corresponds to the user&#39;s ability is often not included with the joystick. If it is included, the replacement of one spring for another is often not something that the user can easily do. This generally leads to original equipment manufacturers and dealers having to stock and supply different springs so that a joystick can be altered by a qualified technician at the request of the user. Accordingly, there is a need to provide joysticks and other wheelchair controls with improved and easily-interchangeable hand control mechanisms that can be configured by the user. 
     SUMMARY 
     The following summary is merely intended to be exemplary. The summary is not intended to limit the scope of the claims. 
     In accordance with one aspect, an example joystick for an electrically-powered wheelchair comprises: a shaft pivotally mounted in a base and configured to control a movement of the electrically-powered wheelchair; a reset sleeve positioned over a lower portion of the shaft proximate the base; a compression spring positioned over the shaft with one end of the compression spring compressed against or fixed to an upper portion of the shaft and an opposing end of the compression spring compressed against the reset sleeve; and a flexible clip positioned over the shaft at the opposing end of the compression spring and between the compression spring and the reset sleeve, the flexible clip being removably positioned on the shaft so as to compress the compression spring between the flexible clip and a point at which the compression spring is compressed against or fixed to the upper portion of the shaft. A compression or a relaxation of the compression spring alters an operational force used to move the shaft relative to the base. 
     In accordance with another aspect, a joystick for an electrically-powered wheelchair comprises: a shaft pivotally mounted in a base and configured to control a movement of the electrically-powered wheelchair; a collar threadedly received on an upper portion of the shaft; a reset sleeve positioned over a lower portion of the shaft proximate the base; and a compression spring positioned over the shaft with one end of the compression spring at the collar and an opposing end of the compression spring compressed against the reset sleeve. The collar is movable on the shaft to either compress the compression spring between the collar and the reset sleeve or to relax the compression spring between the collar and the reset sleeve. A compression or a relaxation of the compression spring alters an operational force used to move the shaft relative to the base. 
     In accordance with another aspect, a joystick for an electrically-powered wheelchair comprises: a shaft pivotally mounted in a base and configured to control a movement of the electrically-powered wheelchair; a collar threadedly received on an upper portion of the shaft; a reset sleeve positioned over a lower portion of the shaft proximate the base; a compression spring positioned over the shaft with one end of the compression spring coupled to or compressed against the collar and an opposing end of the compression spring compressed against the reset sleeve; and an actuator associated with the collar to rotate the collar. The collar is movable on the shaft to either compress the compression spring between the collar and the reset sleeve or to relax the compression spring between the collar and the reset sleeve. A compression or a relaxation of the compression spring alters an operational force used to move the shaft relative to the base. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing aspects and other features are explained in the following description, taken in connection with the accompanying drawings, wherein: 
         FIG. 1A  is a perspective view of a joystick for an electrically-powered wheelchair; 
         FIG. 1B  is a perspective cutaway view of the joystick of  FIG. 1A ; 
         FIGS. 1C-1E  are side cutaway views of the joystick of  FIG. 1A ; 
         FIG. 2A  is a perspective view of one exemplary embodiment of a joystick with a gaiter ( 18 ) removed; 
         FIGS. 2B-2D  are side cutaway views of the joystick of  FIG. 2A ; 
         FIG. 3  is a perspective view of a C-clip for the joystick of  FIGS. 2A-2D ; 
         FIGS. 4A-4C  are side cutaway views of another example embodiment of a joystick employing a nut/threaded shaft combination for compression and expansion of a spring; and 
         FIG. 5  is a side cutaway view of another example embodiment of a joystick employing an electrical actuator for compression and expansion of a spring. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     Although the invention will be described with reference to the example embodiments shown in the drawings, it should be understood that the invention can be embodied in many alternate forms. In addition, any suitable size, shape, or type of elements or materials could be used. 
     Referring to  FIGS. 1A-1E , one example of a joystick for use as an input device for an electrically-powered wheelchair is shown generally at  10  and is hereinafter referred to as “joystick  10 .” 
     The joystick  10  comprises a knob  12  located on an upper end of a shaft (shown at  20  in  FIGS. 1B-1E ) that is operably coupled to and pivotal on a base  14 . A lower end of the shaft  20  is mounted in the base  14  and is configured as a ball  13 . The ball  13  includes a magnet  15  that produces a magnetic field that may be detected by one or more sensors. The sensor(s) may be Hall sensors, which may be part of the joystick  10  or mounted below the magnet  15  on a printed circuit board. Changes detected in the magnetic field by the sensor(s) are used to impart operable functions (such as steering) to the wheelchair. 
     As shown in  FIGS. 1B-1E , a reset sleeve  16  is positioned on and freely moves over the shaft  20 . The reset sleeve  16 , in conjunction with a spring  28 , operates to move the joystick  10  back into a center position ( FIG. 10 ) if no operating force is applied to the joystick  10 . 
     As shown in  FIGS. 1C-1E , a curved edge  17  in the base  14  engages a lower surface of the reset sleeve  16  to move the reset sleeve  16  along the shaft  20  when the joystick  10  is moved from the center position. The spring  28 , which is a compression spring, is coupled to or abutted against a collar  24  on the upper end of the shaft  14 . In the center position ( FIG. 10 ), the spring  28  presses on the reset sleeve  16  with force f 1 , and the spring  28  is at a maximum height h 1 . When the joystick  10  is moved from the center position by an operational force applied by a user ( FIG. 1D ), the spring  28  urges the reset sleeve  16  back into the base  14  with a greater force f 2  and compression of the spring  28  to a lesser height h 2 , thus urging the joystick  10  to return to the center position ( FIG. 10 ). As the joystick  10  is moved even more, as in  FIG. 1E , the force f 3  is increased and the height is reduced even further to h 3  in an effort to move the joystick  10  back to the center position. As the load on the spring  28  increases (f 1  to f 3 ), the operating force required by the user to move the joystick  10  away from the center position will correspondingly increase. 
     A flexible gaiter  18 , as shown in  FIGS. 1A and 1B , is positioned over the shaft  20  with an upper end of the gaiter  18  coupled to the lower end of the knob  12  or to the shaft  20  under the knob  12  and a lower end of the gaiter  18  coupled to the base  14 . In operation of the joystick  10 , the pivotal movement of the shaft  20  relative to the base  14  in a selected direction is made to energize an electrical circuit (via magnet/sensor arrangement), thereby corresponding to a movement or other operation (such as stopping) of the wheelchair. 
     Referring to  FIGS. 2A-2D , one example embodiment of a joystick for use as an input device for an electrically-powered wheelchair is shown generally at  110  and is hereinafter referred to as “joystick  110 .” Although the description herein refers to the use of the joystick  110  with an electrically-powered wheelchair (or simply wheelchair), it should be understood that the joystick  110  may be used with any other type of powered personal mobility vehicle. The joystick  110  is shown with the knob and the gaiter removed. The joystick  110  is similar to joystick  10  and has a reset sleeve  116  on a shaft  120  mounted in a base  114  with an upper section of the shaft  120  including a collar  124  integrally formed with or attached to the shaft  120 . A spring  128  in the form of a compression spring may be coupled to or abutted against the collar  124  and positioned over a lower end of the shaft  120  to urge the reset sleeve  116  into the base  114 . In some embodiments, the collar  124  may not be present, and the spring  128  may be coupled to an upper part of the shaft  120  using any suitable means. 
     A C-clip  130  or clip  130  is positioned over the shaft  120  and between a lower end of the spring  128  and the reset sleeve  16 . Positioning the clip  130  over the shaft  120  and between a free-moving end of the spring  128  and the reset sleeve  16  causes the spring  128  to be compressed more than if the clip  130  was not in place. As with  FIGS. 1A-1E , compression of the spring  128  increases the operational force required by the user to move the shaft  120  in any direction, which in turn requires that a specific amount of operational force be exerted by the user for movement of the joystick  110 . Multiple clips  130  may be positioned on the shaft  120  to further compress the spring  128  to require greater operational force for movement of the joystick  110 . Although the joystick  110  is shown with the spring  128  being coupled to the shaft  120  at an upper end and the clip  130  removably positioned at the lower end of the spring  128 , it should be understood that the spring  128  may be coupled to a lower end of the shaft  120  and the clip  130  positioned at the upper end. As with joystick  10 , as the joystick  110  is moved from a center position ( FIGS. 2A and 2B ) and to a pivoted position ( FIG. 2C ), the force required to move the joystick  110  increases. As the joystick  110  is pivoted further ( FIG. 2D ), the force is further increased. 
     If the user wants to make the joystick  110  easier to pivot or otherwise maneuver, the clip  130  can be removed. Removal of the clip  130  from the shaft  20  accordingly causes the spring  128  to relax and expand and be less compressed, thereby causing the joystick  110  to be movable with a decreased amount of operational force (for example, as a result of a decrease in the user&#39;s strength/mobility) as compared to the configuration in which the clip  130  is used. 
     Referring now to  FIG. 3 , the clip  130  is of an open ring-type of structure and approximates a “C” shape. The clip  130  is fabricated from a material that allows the ends of the clip  130  that define the open portion to sufficiently flex to allow the clip  130  to “snap” over or otherwise be received on the shaft  120 . Materials from which the clip  130  may be fabricated include, but are not limited to, plastics (such as thermoplastics or thermosets), steels (such as stainless steel), shape memory metals, and the like. 
     The foregoing embodiment provides several advantages over current joystick-type control devices. First, use of or removal of the clip(s)  130  is simple as compared to replacement of the spring. The clip  130  as supplied with the wheelchair can be removed by the user without resorting to service calls to the manufacturer or dealer. Second, only one spring  128  is used, thus removing the need to supply additional springs with the wheelchair and avoiding having to store the additional springs. Third, the clip  130  allows for easily scalable operating forces on the joystick  110  in that multiple clips  130  can be used and the operational force used to maneuver the joystick  110  changed as needed (for example, as the user&#39;s ability to operate the joystick  110  changes). 
     Referring to  FIGS. 4A-4C , another example embodiment of a joystick is shown generally at  210 . Instead of a clip  130  as shown in  FIGS. 2A-2D , joystick  210  utilizes a nut/thread combination with a shaft to either compress or allow expansion (relaxation) of the spring. In particular, with the knob and gaiter removed, a lower end of a shaft  220  is pivotally mounted in a base  214  (similar to  FIGS. 2A-2E ) such that the shaft  220  extends upward. A reset sleeve  216  is positioned on a lower section of the shaft  220 . 
     An upper section of the shaft  220  is threaded, and a nut or collar  224  having a corresponding thread is received on the threaded section of the shaft  220 . A spring  228  in the form of a compression spring is positioned over the shaft  220  and between a downward-facing surface of the collar  224  and an upper-facing surface of the reset sleeve  216 . The adjustability of the force used to move the joystick  210  is derived from rotation of the collar  224  such that the collar  224  translates along the length of the shaft  220  either compressing the spring  228  or allowing the spring  228  to expand. Compression or expansion of the spring  228 , as with compression or expansion of the spring  128 , allows the operational force needed to pivot the joystick  210  to be adjustable based on the user&#39;s strength. 
     Referring to  FIG. 5 , another example embodiment of a joystick is shown generally at  410 . Joystick  410  may employ a combination of a threaded collar  424  on a shaft  420  having a threaded upper section such that movement of the collar  424  along the shaft  420  either compresses or allows expansion of a spring  428  similar to joysticks  110  and  210 , but the collar  424  may be rotatable on the shaft  420  using an actuator  50  operably coupled to the collar  424  and configured to cause the rotation of the collar  424  on the shaft  420 . The actuator  50  may be electric and configured to cause movement of a roller  51  (or any other suitable apparatus) that rotates the collar  424 . The actuator  50  may cause controlled movement of the roller  51  via a controller  52  comprising a processor  54  having an associated memory  56  and suitable software. Any suitable user interface  60  (such as a graphical user interface on a control panel on the wheelchair or on a smartphone) may be associated with the actuator  50  and/or controller  52  to allow a user to control the compression and expansion of the spring  428 . Joystick  410  is not limited to the use of a collar/threaded shaft combination as shown, however, as any suitable mechanism capable of being actuated using the controller  52  may be incorporated and used to compress and expand the spring  428 . As with previous embodiments, compression or expansion of the spring  428 , which in this embodiment is controlled via the controller  52 , allows the operational force needed to pivot the joystick  410  to be adjustable based on the user&#39;s strength. 
     One example embodiment of a joystick for an electrically-powered wheelchair comprises: a shaft pivotally mounted in a base and configured to control a movement of the electrically-powered wheelchair; a reset sleeve positioned over a lower portion of the shaft proximate the base; a compression spring positioned over the shaft with one end of the compression spring compressed against or fixed to an upper portion of the shaft and an opposing end of the compression spring compressed against the reset sleeve; and a flexible clip positioned over the shaft at the opposing end of the compression spring and between the compression spring and the reset sleeve, the flexible clip being removably positioned on the shaft so as to compress the compression spring between the flexible clip and a point at which the compression spring is compressed against or fixed to the upper portion of the shaft. A compression or a relaxation of the compression spring alters an operational force used to move the shaft relative to the base. 
     The joystick may further comprise a flexible gaiter positioned between an upper end of the shaft and the base. The joystick may further comprise a knob positioned at the upper end of the flexible gaiter. The flexible clip may be configured in the shape of a C such that ends of the flexible clip flex to allow the flexible clip to engage the shaft. The flexible clip may comprise a plastic, stainless steel, or a shape memory metal. The one end of the compression spring may be coupled to a collar on the shaft. 
     Another example embodiment of a joystick for an electrically-powered wheelchair comprises: a shaft pivotally mounted in a base and configured to control a movement of the electrically-powered wheelchair; a collar threadedly received on an upper portion of the shaft; a reset sleeve positioned over a lower portion of the shaft proximate the base; and a compression spring positioned over the shaft with one end of the compression spring at the collar and an opposing end of the compression spring compressed against the reset sleeve. The collar is movable on the shaft to either compress the compression spring between the collar and the reset sleeve or to relax the compression spring between the collar and the reset sleeve. A compression or a relaxation of the compression spring alters an operational force used to move the shaft relative to the base. 
     The one end of the compression spring may be coupled to the collar and the opposing end of the compression spring may be loosely positioned over the lower portion of the shaft against the reset sleeve. The one end of the compression spring may be compressed against the collar and the opposing end of the compression spring may be loosely positioned over the lower portion of the shaft against the reset sleeve. The shaft may comprise a ball pivotally coupled to the base. The joystick may further comprise a flexible gaiter positioned between an upper end of the shaft and the base. 
     Another example embodiment of a joystick for an electrically-powered wheelchair comprises: a shaft pivotally mounted in a base and configured to control a movement of the electrically-powered wheelchair; a collar threadedly received on an upper portion of the shaft; a reset sleeve positioned over a lower portion of the shaft proximate the base; a compression spring positioned over the shaft with one end of the compression spring coupled to or compressed against the collar and an opposing end of the compression spring compressed against the reset sleeve; and an actuator associated with the collar to rotate the collar. The collar is movable on the shaft to either compress the compression spring between the collar and the reset sleeve or to relax the compression spring between the collar and the reset sleeve. A compression or a relaxation of the compression spring alters an operational force used to move the shaft relative to the base. 
     The actuator may be electric and may be configured to cause a rotation of the collar to move the collar over the threads of the shaft. The actuator may comprise a processor having an associated memory and software, the operation of which may control a movement of the collar over the threads of the shaft. The joystick may further comprise a user interface through which the actuator can be controlled by a user. 
     It should be understood that the foregoing description is only illustrative. Various alternatives and modifications can be devised by those skilled in the art. For example, features recited in the various dependent claims could be combined with each other in any suitable combination(s). In addition, features from different embodiments described above could be selectively combined into a new embodiment. Accordingly, the description is intended to embrace all such alternatives, modifications, and variances which fall within the scope of the appended claims.