Patent Publication Number: US-2020297560-A1

Title: Wheelchair with actuator controlled tilting

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This is a non-provisional application based upon U.S. provisional patent application Ser. No. 62/821,670, entitled “WHEELCHAIR WITH ACTUATOR CONTROLLED TILTING”, filed Mar. 21, 2019, which is incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to wheelchairs, and, more particularly, to adjustable tilt wheelchairs. 
     2. Description of the Related Art 
     Wheelchairs are well-known devices that are used to transport people who have difficulty walking on their own. A typical wheelchair includes a seat that is supported by a chassis with two or more wheels. Many wheelchairs have adjustable back supports to allow adjustment of the seated position of the wheelchair occupant. In many instances, adjustment of the back support is difficult because the occupant is currently seated in the wheelchair. 
     What is needed in the art is a wheelchair with an adjustable back support that can be easily adjusted. 
     SUMMARY OF THE INVENTION 
     The present invention provides a wheelchair with a tilt actuator that can adjust a tilt angle of the wheelchair while allowing collapse of the wheelchair. 
     In some exemplary embodiments provided according to the present invention, a wheelchair includes: a chassis configured to collapse in a width direction of the wheelchair; at least one wheel carried by the chassis; a seat assembly including a seat and a back support carried by the chassis, the back support defining a tilt angle relative to the seat and being pivotable to adjust the tilt angle; and a tilt assembly carried by the chassis and including at least one tilt actuator coupled to the back support, the at least one tilt actuator being configured to pivot the back support and adjust the tilt angle. The chassis is collapsible in the width direction while carrying the at least one actuator to reduce a width of the wheelchair. 
     In some exemplary embodiments, a method of collapsing a wheelchair is provided. The method includes: unlocking a pair of chassis halves from each other, the chassis halves together forming a chassis, the chassis carrying a back support, a seat, and at least one tilt actuator coupled to the back support and configured to adjust a tilt angle of the back support relative to the seat; and moving the chassis halves together in a width direction to reduce a width of the wheelchair without disconnecting the at least one tilt actuator from the back support. 
     One possible advantage that may be realized by exemplary embodiments disclosed herein is that the wheelchair can be collapsed without significant disassembly, providing a convenient way to store and/or transport the wheelchair when it is unoccupied. 
     Another possible advantage that may be realized by exemplary embodiments disclosed herein is that the tilt actuator can be controlled by a controller to precisely and reliably pivot the back support to one or more defined positions. 
     Yet another possible advantage that may be realized by exemplary embodiments disclosed herein is that the back support can be pivoted to a wide variety of positions to, for example, position a wheelchair occupant for transfer out of the wheelchair or position a wheelchair occupant to an accessible position for medical care. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of exemplary embodiments of the invention taken in conjunction with the accompanying drawings, wherein: 
         FIG. 1  is a partially exploded perspective view of an exemplary embodiment of a wheelchair, provided in accordance with the present invention; 
         FIG. 2  is a rear view of the wheelchair of  FIG. 1 ; 
         FIG. 3  is a rear perspective view of the wheelchair of  FIGS. 1-2 ; 
         FIG. 4  is a side view of the wheelchair of  FIGS. 1-3  with a back support of the wheelchair at a first tilt angle; 
         FIG. 5  is a side view of the wheelchair of  FIGS. 1-4  after the back support has pivoted to a second tilt angle; 
         FIG. 6  is a side view of the wheelchair of  FIGS. 1-5  after the back support has pivoted to a third tilt angle; 
         FIG. 7  is a rear view of the wheelchair of  FIGS. 1-6  after the wheelchair has been collapsed in a width direction; 
         FIG. 8  is a top view of the wheelchair of  FIGS. 1-7  after the back support of the wheelchair has been collapsed; 
         FIG. 9  is a top view of the wheelchair of  FIGS. 1-8  after the back support and chassis have been collapsed in the width direction to reduce an overall width of the wheelchair; and 
         FIG. 10  is a flow chart illustrating an exemplary embodiment of a method of collapsing a wheelchair, provided in accordance with the present invention. 
     
    
    
     Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate embodiments of the invention and such exemplifications are not to be construed as limiting the scope of the invention in any manner. 
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the drawings, and more particularly to  FIG. 1 , an exemplary embodiment of a wheelchair  100  provided according to the present disclosure is illustrated. The wheelchair  100  generally includes a chassis  110 , a seat assembly  120  carried by the chassis  110 , and a tilt mechanism  130  carried by chassis  110  and coupled to the seat assembly  120 . 
     The chassis  110  carries the various components of the wheelchair  100 . The chassis  110  may include multiple frame members, such as a side frame and a cross frame. A pair of front wheels  18  may be mounted to the chassis  110  on a front axle  17  by a bearing  16  and connect to the chassis  110  via a fork  19 . The front wheels  18  may be, for example, casters that can pivot about a stem of the fork  19 , with bearings  21  being provided to promote smooth pivoting. A fork stem lock  22  may be associated with the stem of the fork  19  to lock the wheels  18  in position, when desired. 
     A pair of rear wheels  15  can be mounted to the chassis  110  by rear axle bolts  12 , which can have an axle cap  12   a , and an associated rear axle bearing  13 . In some embodiments, the rear wheels  15  have a larger diameter than the front wheels  18 . The rear wheels  15  can include a rim with a handrim attached to the rim by one or more spacers  11 . An anti-tipping mechanism  14  may also be associated with one or both of the rear wheels  15  to reduce the risk of the wheelchair  100  tipping during use. A wheel lock  23  may be coupled to one or both of the rear wheels  15  to lock movement of the wheels  15 , when desired. 
     The seat assembly  120  may include an optional headrest pillow  1 , which may be a neck support pad, at a top that is coupled to a headrest  2 . The headrest pillow  1  and headrest  2  may support a neck and head of an occupant using the wheelchair  100 . A back support  3 , which may include upholstery and also be referred to as a “backrest,” is coupled to the headrest  2  and is pivotably coupled to the chassis  110 . A seat  24 , which may also include upholstery, is coupled to the chassis  110 . Upholstery screws  25  may be used to hold the upholstery against the back support  3  and the seat  24 . A pair of arm rests  26 , which may include pads  26   a , are coupled to the chassis  110 , with the arm rests  26  disposed on opposite sides of the seat  24 . The arm rests  26  can be mounted on a slide tube  30  with an arm release button  29  that allows the arm rests  26  to slide off the chassis  110  and be removed from the wheelchair  100  during, for example, transportation or storage of the wheelchair  100 . A pair of removable leg rests  20  can also be mounted to the chassis  110  to provide rests for an occupant&#39;s legs and feet during use. A spreader bar  8  and one or more associated spreader bar knobs  7  for locking the spreader bar  8  may be mounted to a rear of the back support  3 . 
     Referring still to  FIG. 1 , and referring also to  FIGS. 2-3 , it can be seen that the tilt mechanism  130  couples to the back support  3  to tilt the back support  3  with respect to the seat  24 . To tilt the back support  3 , the tilt mechanism  130  includes one or more tilt actuators, illustrated as a pair of tilt actuators  10 , that are mounted to the back support  3  by respective actuator mounts  9  and fasteners  9   a . The back support  3  may include a pair of back bars  36  that are each pivotably coupled to the chassis  110 , with each of the actuator mounts  9  and tilt actuators  10  mounting to a respective back bar  36  of the back support  3 . The back bars  36  may be coupled to each other by the spreader bar  8 , which can prevent collapse of the back support  3  by keeping the back bars  36  spread apart. In some embodiments, the tilt actuators  10  are electrically powered actuators, illustrated as being powered by an electrically coupled battery  33 , but it should be appreciated that the tilt actuators  10  can be any suitable type of actuators, such as pneumatic or hydraulic cylinders. The tilt actuators  10  can also be mounted to pivot brackets that are rigidly mounted to the chassis  110 . The battery  33  may be mounted to the chassis  110  by a battery tray mount  32  that is partially supported by a battery strap  31 . In some embodiments, the battery  33  is a rechargeable battery, with the wheelchair  100  also including a battery charger  35  for recharging the battery  33  and, if needed, a battery adapter  34  to allow the battery charger  35  to connect to a wall outlet. 
     To control tilting of the back support  3 , a tilt controller  6  is provided that is electrically coupled to the tilt actuators  10 . The tilt controller  6  may be electrically coupled to the tilt actuators  10  by, for example, a wire  5  that is at least partially held within a wire loom  4 . The tilt controller  6  may be a two-way switch that allows a user to tilt the back support  3  backwards and forwards by pressing respective buttons on the tilt controller  6 . Pressing the forward button, for example, may cause the tilt actuators  10  to each extend a respective actuator rod  38  to force the back support  3  forward so the back support  3  is more upright, i.e., closer to forming a 90° tilt angle with the seat  24 . Pressing a backward button, in contrast, can cause the tilt actuators  10  to retract the actuator rods  38  and force the back support  3  rearward so the back support  3  is less upright, i.e., closer to forming a 180° tilt angle with the seat  24 . Thus, an occupant in the wheelchair  100  can conveniently control tilting of the back support  3  to a desired tilt utilizing the tilt controller  6  without requiring assistance from a care provider to manually adjust the back support  3 . In some embodiments, the actuator mounts  9  act as mechanical stops to prevent excessive retraction of the actuator rods  38 ; in such embodiments, the actuator mounts  9  contact the body of the tilt actuators  10  when the actuator rods  38  are fully retracted. 
     In some embodiments, the tilt controller  6  is mounted to, or adjacent to, one of the arm rests  26  for easy accessibility by an occupant in the wheelchair  100 . The tilt controller  6  can be mounted to either arm rest  26 , depending on the needs of the normal rider of the wheelchair  100 . For example, if the normal rider of the wheelchair  100  has limited dexterity in their right hand, the tilt controller  6  can be mounted to the left arm rest  26  so the occupant can control the tilt of the wheelchair  100  using their left hand. In some embodiments, both arm rests  26  are equipped with a respective tilt controller  6  so an occupant can use either hand to adjust the tilt of the wheelchair  100 . Such configurations may be useful in, for example, hospital settings where the wheelchair  100  is likely to be used by many different riders throughout its service life. The tilt controller  6  can also be placed at other locations on the wheelchair  100 , such as one of the leg rests  20 , depending on the occupant&#39;s physical capabilities. The wheelchair  100  may include a controller mount on each arm rest  26  and/or other locations on the wheelchair  100  that couples to the tilt controller  6  and holds the tilt controller  6  in the mounting location, allowing the tilt controller  6  to be placed in a variety of different locations of the wheelchair  100 . 
     The tilt controller  6  may include at least one activation switch, such as a joystick and/or buttons, that can be used to control tilting of the back support  3 . When a user activates the activation switch, the tilt controller  6  can output control signals to the tilt actuator(s)  10  that cause the tilt actuator(s)  10  to pivot the back support  3  and adjust the tilt angle. The activation switch(es) included in the tilt controller  6  may be adjusted, as needed, for use by a wheelchair occupant. For example, a tilt controller including a joystick may be desired by a user who has limited dexterity and is unable to reliably press buttons. It should thus be appreciated that the tilt controller  6  can be configured in many different ways to control the tilt actuator(s)  10  and adjust the tilt angle of the back support  3 . 
     Referring now to  FIGS. 4-6 , the wheelchair  100  is illustrated in various positions with different degrees of tilt. As illustrated in  FIG. 4 , the wheelchair  100  is in an upright position with the back support  3  oriented at a first tilt angle that is nearly perpendicular with the seat  24 . When the tilt controller  6  is activated to tilt the back support  3  rearwardly, as illustrated in  FIG. 5 , the tilt actuators  10  can retract their respective actuator rods  38  to pull the back support  3  rearwardly and cause rearward tilt of the back support  3  to a second tilt angle that is greater than the first tilt angle illustrated in  FIG. 4 . The tilt actuators  10  may also be pivotably mounted to their respective pivot brackets and pivot during tilting of the back support  3 . Further tilting of the back support  3  to a third tilt angle, which is illustrated in  FIG. 6 , can be achieved by further retraction of the actuator rods  38  of the tilt actuators  10 . To return the back support  3  to a more upright position, the tilt controller  6  can be activated to cause extension of the actuator rods  3  of the tilt actuators  10 , as can be appreciated from  FIGS. 4-6 . The back support  3  may be pivotable across a range of tilt angles between 90° and 180°, with the tilt actuators  10  being configured to pivot the back support  3  across the entire range of tilt angles. In some embodiments, the tilt actuators  10  are configured so extension of the actuator rods  38  causes the back support  3  to tilt backward and retraction of the actuator rods  38  causes the back support  3  to tilt forward. It should thus be appreciated that the tilt actuators  10  may be configured in a variety of ways to pivot the back support  3  across the range of tilt angles. 
     In some embodiments, the tilt controller  6  includes a memory  37  that allows the tilt controller  6  to be programmable. For example, the tilt controller  6  may be configured to store one or more defined tilt angles in the memory  37 . The defined tilt angle(s) may be programmed into the memory  37  by a user and/or by the manufacturer to allow for easy, reproducible adjustment of the back support  3  to various positions. Exemplary tilt angles may be, but are not limited to, the first tilt angle illustrated in  FIG. 4  and/or a tilt angle of 180° where the back support  3  is generally in-plane with the seat  24 . When a user recalls the defined tilt angle(s) using the tilt controller  6 , which may be done in a variety of known ways, the tilt controller  6  outputs one or more control signals to the tilt actuators  10  to pivot the back support  3  to the stored defined tilt angle that is selected. The tilt controller  6  may be configured to determine a current tilt angle of the back support  3  relative to the seat  24  based on a variety of measurements, including but not limited to an extension of the actuator rod(s)  38  of the tilt actuator(s)  10  and/or a direct measurement of the tilt angle of the back support  3 . In this respect, the tilt controller  6  may be electrically coupled to one or more sensors  39  that output measurement signals to the tilt controller  6  that correspond to a respective measurement. It should thus be appreciated that the tilt controller  6  can be configured in a variety of ways to make it easier for an occupant and/or a healthcare professional to reliably adjust the tilt angle of the back support  3  to a number of defined tilt angles. 
     From the foregoing, it should be appreciated that the wheelchair  100  provided in accordance with the present disclose allows an occupant, or other user, to conveniently and easily adjust a tilt angle of the wheelchair  100  using the tilt controller  6  and tilt actuator(s)  10 . Control of the tilt actuator(s)  10  by the tilt controller  6  allows an occupant or other user to adjust the tilt angle of the wheelchair  100  without having to, for example, pivotably unlock the back support  3  from the chassis  110  and manually tilt the back support  3  before pivotably re-locking the back support  3 . Further, the tilt angle can be gradually adjusted by the tilt controller  6  and tilt actuator(s)  10  to find a position of the back support  3  that is comfortable for the occupant and/or conducive for medical help to move the occupant. Since the tilt controller  6  can be easily operated by an occupant without assistance, an occupant can independently adjust the tilt of the wheelchair  100  to improve their comfort whenever it is desired. Thus, the wheelchair  100  provided according to the present disclosure allows easy and convenient adjustment of the tilt angle of the wheelchair  100 . 
     Referring now to  FIGS. 7-9 , the wheelchair  100  is illustrated in a collapsed position where the wheelchair  100  has been collapsed in a width direction W, defined as a direction that is parallel to an axis extending through a rotational center of the wheels  15  or  18 . The wheelchair  100  may be placed in the collapsed position to, for example, transport and/or store the wheelchair  100 . To collapse the wheelchair  100  in the width direction W, a collapse mechanism  700  can be coupled to chassis bars  40 A,  40 B of the chassis  110 . The collapse mechanism  700  can include a pair of collapse bars  701 A,  701 B that are pivotably coupled together at a pivot  702 , which may be a pivot pin or any other type of element that pivotably couples the collapse bars  701 A,  701 B together. 
     A pivot lock  703 , illustrated as a screw, may be tightened or loosened to lock or unlock, respectively, the collapse bars  701 A,  701 B from each other. When the collapse bars  701 A,  701 B are unlocked, the collapse bars  701 A,  701 B can be pivoted together about the pivot  702  to collapse the wheelchair  100  in the width direction W, as can be seen in  FIG. 7 . The spreader bar  8  is also unlocked by loosening the spreader bar knob(s)  7 , which allows the spreader bar  8  to drop and the back support  3  to collapse in the width direction W by pulling up on the seat  24  to collapse the back bars  36  toward each other in the width direction W. In this respect, the chassis  110  can be formed as two chassis halves  111 A,  111 B that are movably connected together by the collapse mechanism  700  and by the back bars  36  via the spreader bar  8  such that the wheelchair  100  can be collapsed in the width direction W. While both chassis halves  111 A,  111 B are illustrated and described as being movable, it should be appreciated that, in some embodiments, only one of the chassis halves  111 A,  111 B is movable; in such an embodiment, the chassis  110  is collapsible in the width direction W by moving the movable chassis half toward the other chassis half. Further, while the chassis halves  111 A,  111 B are described as both being moved in the width direction W, it should be appreciated that each of the chassis halves  111 A,  111 B is movable in the width direction W independently of the other chassis half  111 B,  111 A by pivoting only one of the collapse bars  701 A,  701 B about the pivot  702 . 
     As can be appreciated from  FIG. 7 , the mounting of the tilt actuators  10  to the back support  3  does not interfere with collapse of the wheelchair  100 . Each of the tilt actuators  10  may be coupled to a respective one of the back bars  36  and chassis halves  111 A,  111 B, as illustrated, so the tilt actuators  10  do not need to be removed to collapse the chassis  110 , and thus the wheelchair  100 , in the width direction W, i.e., the chassis  110  is collapsible in the width direction W while carrying the tilt actuators  10 . Thus, the tilt mechanism  130  allows controlled tilting of the wheelchair  100  by the tilt actuators  10  while still allowing the wheelchair  100  to easily and conveniently collapse for storage and/or transportation. 
     While some known wheelchairs include an actuator to tilt the back support, such wheelchairs are large and bulky. This makes transportation and storage of the wheelchairs difficult for many users and/or their healthcare providers. Particularly, known wheelchairs with actuators to tilt the back support are unable to collapse in the width direction, which makes it difficult to place the wheelchair in a transport vehicle, such as a car. The wheelchair  100  provided according to the present invention, on the other hand, has a chassis  110  that is collapsible in the width direction W while the tilt actuator(s)  10  is carried by the chassis  110 . The chassis  110  being collapsible allows the width of the wheelchair  100  to be considerably reduced, making it easier to transport and/or store the wheelchair  100 . Further, it is relatively easy to collapse the wheelchair  100  because the tilt actuator(s)  10  does not need to be removed in order to collapse the chassis  110 . In this respect, the wheelchair  100  provided according to the present invention is easy to transport and can be transported in common passenger vehicles, such as in the trunk. 
     Referring now to  FIG. 10 , an exemplary embodiment of a method  1000  of collapsing a wheelchair  100  provided according to the present invention is illustrated. The method  1000  includes unlocking  1001  a pair of chassis halves  111 A,  111 B, which together form a chassis  110 , from each other. The chassis  110  carries a back support  3 , a seat  24 , and at least one tilt actuator  10  coupled to the back support  3  and configured to adjust a tilt angle of the back support  3  relative to the seat  24 . Unlocking  1001  the chassis halves  111 A,  111 B from each other may include, for example, loosening a pivot lock  703  of a collapse mechanism  700  including a pair of collapse bars  701 A,  701 B that are pivotably coupled together and couple the chassis halves  111 A,  111 B together at a pivot  702 . The chassis halves  111 A,  111 B are moved  1002  together in a width direction W to reduce a width of the wheelchair  100  without disconnecting the at least one tilt actuator  10  from the back support  3 , as previously described. In some embodiments, the method  1000  further includes unlocking  1003  a spreader bar  8  that couples together two back bars  36  on opposite sides of the back support  3 . After the wheelchair  100  is collapsed, the wheelchair  100  can be expanded to its normal operating width by the reverse actions, i.e., moving the chassis halves  111 A,  111 B away from each other in the width direction W and locking the chassis halves  111 A,  111 B together. 
     While this invention has been described with respect to at least one embodiment, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.