초록 ▼

Means for reconfiguring a wheelchair are disclosed wherein a user or an occupant of the wheelchair is enabled to repeatably alternate the wheelchair between an original load-bearing configuration and a modified load-bearing configuration by engaging and disengaging a ground-contacting adaptive imple

Means for reconfiguring a wheelchair are disclosed wherein a user or an occupant of the wheelchair is enabled to repeatably alternate the wheelchair between an original load-bearing configuration and a modified load-bearing configuration by engaging and disengaging a ground-contacting adaptive implement operatively connected to a load transitioning mechanism, said load transitioning mechanism adapted for connection to a forward portion of the wheelchair. Embodiments according to the present invention enable an occupant of the wheelchair to alternate the wheelchair, through a cyclic operation sequence, between the original configuration and the modified configuration by toggling of a manipulable switch and subsequent momentary reclining of the wheelchair. The user willfully effectuates a change in the angular disposition of the ground-contacting adaptive implement relative to the wheelchair about a substantially horizontal joint axis wherein in the modified configuration a deployed angular orientation is maintained under load-bearing conditions during travel of the wheelchair in all directions. Embodiments of the present invention enable wheelchair reconfiguration with simplicity of operation while ensuring rigid attachment of a ground-contacting adaptive implement to the wheelchair to confer special functionalities to the wheelchair while preserving comfort and safety for the user while the wheelchair is in the modified load-bearing configuration.

대표청구항 ▼

1. A load transitioning mechanism for alternating a wheelchair between an original load-bearing configuration and a modified load-bearing configuration, the wheelchair comprising a frame having a front portion, the wheelchair further comprising a pair of symmetrically-opposing rear wheels and a pair

1. A load transitioning mechanism for alternating a wheelchair between an original load-bearing configuration and a modified load-bearing configuration, the wheelchair comprising a frame having a front portion, the wheelchair further comprising a pair of symmetrically-opposing rear wheels and a pair of symmetrically-opposing front caster wheels, the load transitioning mechanism comprising: I. An overrunning clutch having a joint axis, the overrunning clutch comprising a first bearing surface, a second bearing surface, and a movable bearing, the first bearing surface unified with a fixed joint body, the second bearing surface unified with a movable joint body, the second bearing surface capable of rotating relative to the first bearing surface about the joint axis, the fixed joint body adapted to be immovably affixed to the front portion of the frame of the wheelchair, the movable joint body adapted for affixing a ground-contacting implement, the movable joint body capable of rotating relative to the fixed joint body in a first direction about the joint axis, the movable bearing adapted to transmit torque between the first and second bearing surfaces about the joint axis;II. a force sustainment subassembly comprising a manipulable biasing switch and a forward-force sustaining spring, the force sustainment subassembly adapted to be toggled between: a.) a first biasing state, wherein the forward-force sustaining spring is deflected in a forward direction by the manipulable biasing switch to apply a forward sustaining force to the movable bearing to pre-load the movable bearing to enable movement of the movable bearing into a position of load-bearing torque transmission between the first and second bearing surfaces, and b.) a second biasing state wherein the forward-force sustaining spring is relaxed by the manipulable biasing switch to remove the forward sustaining force from the movable bearing to enable the movable bearing to move out of the position of load-bearing torque transmission between the first and second bearing surfaces;wherein the load transitioning mechanism enables a user to alternate the wheelchair between the original load-bearing configuration and the modified load-bearing configuration upon manipulating the manipulable biasing switch and subsequently reclining the wheelchair, wherein while the wheelchair is in the original load-bearing configuration, a forward portion of a load carried by the wheelchair is supported by the pair of symmetrically-opposing front caster wheels, and wherein while the wheelchair is in the modified load-bearing configuration, the forward portion of the load carried by the wheelchair is substantially supported by the ground-contacting implement affixed to the movable joint body. 2. The load transitioning mechanism of claim 1, adapted for attachment and deployment of a wheel having an axis of rotation, wherein, while the wheelchair is in the modified load-bearing configuration, the ground-contacting implement moves in concert with movements of the wheelchair. 3. The load transitioning mechanism of claim 1, adapted for attachment and deployment of a caster wheel assembly, said caster wheel assembly comprising a pivotable portion having a vertical pivot axis wherein, while the wheelchair is in the modified load-bearing configuration, the pivotable portion of the caster wheel assembly pivots about the vertical pivot axis in response to changes in the direction of the wheelchair enacted by the user. 4. The load transitioning mechanism of claim 1, the manipulable biasing switch comprising a lever and a control knob configured for receiving a manual force applied by the user and for transferring said manual force to effectuate a state alternation of the force sustainment subassembly. 5. The load transitioning mechanism of claim 4, the forward-force sustaining spring being operatively integrated with the lever of the manipulable biasing switch. 6. The load transitioning mechanism of claim 5, capable of retaining the lever in a first discrete rotational orientation about the joint axis, wherein applying manual force against the control knob to dispose the lever in the first discrete rotational orientation deflects the spring to impart the forward sustaining force to the movable bearing. 7. The load transitioning mechanism of claim 6, the forward-force sustaining spring being further capable of deflection in a second, opposing direction wherein manually forcing the control knob to dispose the lever in a second discrete rotational orientation deflects the spring to impart a reverse sustaining force to the movable bearing. 8. The load transitioning mechanism of claim 4, further comprising a reverse-force sustaining spring, the manipulable biasing switch being operatively interposed between the forward-force sustaining spring and the reverse-force sustaining spring, wherein, while the forward-force sustaining spring is deflected in the first direction by the manipulable biasing switch, the forward-force sustaining spring applies a sustaining force to the movable bearing in the first direction, and wherein while the reverse-force sustaining spring is deflected in the second, opposing direction by the manipulable biasing switch, the reverse-force sustaining spring applies a sustaining force to the movable bearing in the second, opposing direction. 9. The load transitioning mechanism of claim 8, the manipulable biasing switch adapted to be maintained in the first discrete orientation while the force sustainment subassembly is in the first biasing state, the manipulable biasing switch further adapted to be maintained in the second discrete orientation while the force sustainment subassembly is in the second biasing state. 10. The load transitioning mechanism of claim 9, wherein a net sustaining force applied against the movable bearing by the forward-force sustaining spring and the reverse-force sustaining spring urges the movable bearing either into or out of the position of load-bearing torque transmission between the first and second bearing surfaces. 11. The load transitioning mechanism of claim 1, wherein, while the wheelchair is in the modified load-bearing configuration, upon user manipulation of the control knob to effectuate a state alternation of the force sustainment subassembly to enable movement of movable bearing out of the position of load-bearing torque transmission between the first and second bearing surfaces, frictional forces between the movable bearing and at least one of the first and the second bearing surfaces maintain the movable bearing in the position of load-bearing torque transmission until the user reclines the wheelchair to engender relative rotation between the movable joint body and the fixed joint body of the overrunning clutch to remove frictional forces upon the movable bearing. 12. The load transitioning mechanism of claim 1, further including a travel-limiting element and a limit stop which, upon contact thereof, restrict downward rotation of the ground-contacting implement affixed to the movable joint body of the overrunning clutch, wherein, during transitioning the wheelchair to the modified load-bearing configuration, the ground-contacting implement assumes a predetermined angular orientation relative to the frame of the wheelchair. 13. The load transitioning mechanism of claim 1, wherein while the wheelchair is in the original load-bearing configuration with the load transitioning mechanism and the ground-contacting implement operatively connected to the frame of the wheelchair, manipulation of the manipulable biasing switch to place the force sustainment subassembly in the first biasing state, followed by backward reclining of the wheelchair results in: Downward rotation of the ground contacting implement about the joint axis passing through the load transitioning mechanism;A position shifting of the forward caster wheels to an elevation substantially above the ground surface;Load-bearing contact of the ground-contacting implement with the ground surface;Transmission of torque between the first and second bearing surfaces about the joint axis by the movable bearing; andSharing of the wheelchair load by the rear drive wheels and the ground-contacting implement, with the wheelchair maintained in a reclined position;and wherein, while the ground-contacting implement is engaged with the ground and sharing the load supported by the wheelchair with the rear drive wheels, manipulation of the manipulable biasing switch to place the force sustainment subassembly in the second biasing state followed by backward reclining of the wheelchair and subsequent return of the wheelchair to a forward position results in:Upward rotation of the ground contacting implement about the joint axis passing through the load transitioning mechanism;Release of load-bearing contact of the ground-contacting implement from the ground surface;Reengagement of the forward caster wheels with the ground surface;Release from torque transmission between the first and second bearing surfaces about the joint axis by the movable bearing; andSharing of the wheelchair load by the rear drive wheels and the forward caster wheels, with the wheelchair maintained in an upright, unreclined position. 14. The load transitioning mechanism of claim 1, adapted for mounting onto either the first side or the second side of the frame of the wheelchair, the load transitioning mechanism further adapted to couple with an auxiliary caster assembly which is separable from the load transitioning mechanism, wherein the load transitioning mechanism remains affixed to the frame of the wheelchair while the user decouples the auxiliary caster wheel assembly from the load transitioning mechanism. 15. The load transitioning mechanism of claim 1, adapted for mounting onto either the first side or the second side of the frame of the wheelchair, the load transitioning mechanism connected to an auxiliary caster wheel assembly, wherein the load transitioning mechanism and the auxiliary caster wheel assembly separate from the frame of the wheelchair upon the user decoupling the load transitioning mechanism from the wheelchair. 16. The load transitioning mechanism of claim 1, adapted for mounting onto both the first side and the second side of the frame of the wheelchair, the load transitioning mechanism connected to an auxiliary caster wheel assembly, wherein the load transitioning mechanism and the auxiliary caster wheel assembly separate from the frame of the wheelchair upon the user decoupling the load transitioning mechanism from the wheelchair. 17. An alternatable reconfiguration apparatus for a wheelchair for enabling releasable attachment and reversible deployment of a ground-contacting implement by a user of the wheelchair, the wheelchair comprising a frame having a front portion, the wheelchair further comprising a pair of symmetrically-opposing rear wheels and a pair of symmetrically-opposing front caster wheels, the apparatus comprising a load transitioning mechanism for alternating the wheelchair between an original load-bearing configuration and a modified load-bearing configuration, said load transitioning mechanism comprising an overrunning clutch having at least one movable bearing, said load transitioning mechanism further comprising a force-sustainment subassembly adapted to move the movable bearing into and out of a position of load-bearing torque transmission to enable alternation between said original load-bearing configuration and said modified load-bearing configuration, the apparatus further comprising a caster wheel assembly, said caster wheel assembly comprising a wheel having a rotation axis, said caster wheel assembly further comprising a pivotable portion having a vertical pivot axis; wherein, while the wheelchair is in the original load-bearing configuration, a forward portion of a load carried by the wheelchair is supported by the pair of symmetrically-opposing front caster wheels, and while the wheelchair is in the modified load-bearing configuration, the forward portion of the load carried by the wheelchair is substantially supported by the ground-contacting implement, and while the wheelchair is in the modified load-bearing configuration, the wheel rotates about the rotation axis in concert with movements of the wheelchair, the pivotable portion of the caster wheel assembly being capable of pivoting about the vertical pivot axis in response to changes in the direction of the wheelchair enacted by the user. 18. The alternatable reconfiguration apparatus for a wheelchair of claim 17, adapted to enable releasable attachment and deployment of a first ground-contacting implement relative to a first side of the frame of the wheelchair and releasable attachment and deployment of a second ground-contacting implement relative to a second side of the frame of the wheelchair. 19. A convertible wheelchair system comprising: a frame having a front region adapted for releasable attachment of a wheel implement;a pair of symmetrically-opposing rear wheels and a pair of symmetrically-opposing front caster wheels, said front caster wheels adapted for supporting a forward portion of a load supported by the frame while the convertible wheelchair system is in an original load-bearing configuration;a wheel implement comprising a wheel having an axis of rotation, the wheel adapted for ground contact, the wheel implement further adapted for supporting the forward portion of the load supported by the frame while the convertible wheelchair system is in a modified load-bearing configuration; anda load transitioning mechanism for alternating the convertible wheelchair system between the original load-bearing configuration and the modified load-bearing configuration, the load transitioning mechanism comprising an overrunning clutch having at least one movable bearing, said load transitioning mechanism further comprising a force-sustainment subassembly adapted to move the movable bearing into and out of a position of load-bearing torque transmission to enable alternation of the convertible wheelchair system between the original load-bearing configuration and the modified load-bearing configuration;wherein the convertible wheelchair system enables reversible deployment of the wheel implement to the modified load-bearing configuration by a seated occupant of the convertible wheelchair system. 20. The convertible wheelchair system of claim 19, adapted to enable reversible deployment of a first wheel implement relative to a first side of the frame of the wheelchair and reversible deployment of a second wheel implement relative to a second side of the frame of the wheelchair.