Bi-directional anti-tip system for powered wheelchairs
AssigneePride Mobility Products Corporation
InventorsJames P. Mulhern, Michael J. Rozaieski
Life of this patent
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Abstract
A bi-directional anti-tip system for a wheelchair includes a pair of anti-tip system subassemblies actively lifting a leading anti-tip wheel when traveling in either forward or reverse directions. The anti-tip system subassemblies operate to couple a leading anti-tip wheel to the drive assembly such that pivot motion thereof effects vertical displacement of the leading anti-tip wheel and to decouple a trailing anti-tip wheel from the drive assembly to null pivot motion inputs therefrom. In one embodiment, rheonetic links actively couple and decouple the anti-tip system subassemblies. The system may also include compliant bearings or extensible links for inward displacement of the anti-tip wheel upon impact with a curb.
Claims17
A wheelchair comprising:
- a seat;
- a frame supporting the seat;
- a pair of drive wheels supporting and mobilizing the frame;
- a drive system capable of propelling the wheelchair forwardly and rearwardly, the drive system including a pair of drive assemblies pivotally mounted to the frame at a pivot axis, each said drive assembly applying input torque to one of the drive wheels;
- at least one bi-directional anti-tip system including a pair of anti-tip assemblies mounted to the frame and disposed on opposite sides of the drive pivot axis, each of the anti-tip assemblies including an anti-tip wheel, each anti-tip wheel alternately being a leading anti-tip wheel or a trailing anti-tip wheel depending on the direction in which the drive system is propelling the wheelchair, the bi-directional anti-tip system operative to (i) couple the leading anti-tip wheel to one of the drive assemblies such that a pivoting motion thereof effects vertical displacement of the leading anti-tip wheel, and to simultaneously (ii) decouple the trailing anti-tip wheel from the drive assembly to null pivot motion inputs therefrom, and
- a suspension assembly biasing the anti-tip wheels to a predetermined operating position.
A bi-directional anti-tip system for a power wheelchair having a frame, the wheelchair having a drive system capable of propelling the wheelchair forwardly and rearwardly, the drive system pivotably mounted to the frame, the bi-directional anti-tip system comprising:
- a pair of anti-tip assemblies mounted to the frame, each anti-tip assembly including an anti-tip wheel rotatably supported by a wheel mount, the anti-tip wheel of one of the anti-tip assemblies located forwardly of the frame and the anti-tip wheel of the other one of the anti-tip assemblies located rearwardly of the frame, each anti-tip wheel being a leading anti-tip wheel or a trailing anti-tip wheel depending on the direction in which the drive system is propelling the wheelchair, each anti-tip assembly including at least one link pivotably connected to the wheel mount and to the frame for elevating the anti-tip wheel from a normal wheel position;
- and
- an actuator assembly connected to each anti-tip assembly and to the drive system, the actuator assembly adapted to simultaneously (i) couple the leading anti-tip wheel to the drive system such that a pivoting motion thereof effects vertical displacement of the leading anti-tip wheel, and (ii) decouple the trailing anti-tip wheel from the drive system to null pivot motion inputs therefrom.
A wheelchair comprising:
- a frame;
- a drive system including a motor capable of propelling the wheelchair forwardly and rearwardly, the drive system mounted to the frame for pivot about a pivot axis in response to a torque generated by the motor, the drive system respectively pivoting in opposite first and second pivot directions from a neutral motor position during forward and rearward propulsion of the wheelchair;
- and
- a bi-directional anti-tip system having front and rear anti-tip assemblies each including a wheel rotatably supported by a wheel mount and a linkage including at least one link pivotably connected to the frame and to the wheel mount to elevate the wheel from a normal wheel position when the linkage is pivoted, the front and rear wheels respectively located forwardly and rearwardly of the frame,
- the anti-tip system also having a linkage actuator pivotably connected to each of the front and rear anti-tip assemblies and to the drive system, the anti-tip system adapted to couple the linkage actuator and the front linkage during pivot of the drive system in the first direction for pivot of the front linkage while simultaneously nulling pivot motion of the rear linkage, the anti-tip system further adapted to couple the linkage actuator and the rear linkage during pivot of the drive system in the second direction for pivot of the rear linkage while simultaneously nulling pivot motion of the front linkage.
Dependencies are inferred from the claim text.