US 5,211,414 A · Wheelchair

Abstract

A lightweight, optionally foldable wheelchair which allows the user maximum control over both travel direction and seat position. The wheelchair is driven manually by an arrangement of drive gears, which are actuated by a drive gear selector and operated by rotating a pair of opposed handwheels, one of which is contacted by each of the occupant's hands. One of four or more different gears may be selected, including a "Forward Only" and a "Reverse Only" gear, which allow travel only in the direction selected. A dual function shift lever supports the drive gear selector and may be activated to disengage the drive gears and engage a seat positioning gear. When the seat positioning gear is engaged, rotation of the handwheels by the wheelchair occupant will activate a seat raising mechanism which moves the seat from a horizontal sitting position to a substantially vertical position toward the rear of the wheelchair. The leg rests and foot rests fold and are engaged by the wheelchair frame so that they are guided away from the front of the chair, thus enabling the occupant to assume a standing position without changing the center of gravity of the chair.

Claims46

Dependent claims

A lightweight, foldable manually driven wheelchair including:

(a) travel wheel means for propelling the wheelchair along a desired travel path;
(b) manually activated drive gear means for controlling the direction of travel along the travel path;
(c) manually actuated body positioning means for moving the position of the wheelchair occupant between sitting and standing positions without changing the center of gravity of the wheelchair;
(d) shift control means shiftable between a first position in which said drive gear means can be activated and a second position in which said body positioning means can be actuated for allowing the wheelchair occupant to control selectively the direction of travel or body position of the wheelchair;
(e) dual function handwheel means for operation by the wheelchair occupant to drive said drive gear means when said drive gear means is activated and to move said body positioning means when said body positioning means is actuated;
and
(f) foldable frame means for supporting said travel wheel means, said drive gear means, said body positioning means, said shift control means and said handwheel means in operational relationship.

4 more elements

A manually driven wheelchair including a travel gear drive system, a seat, leg support means for supporting the legs and feet of the wheelchair occupant and dual drive gear actuating and seat positioning means for controlling the travel of the wheelchair and for changing the position of the seat from a first position in which the wheelchair occupant is supported by the seat in a sitting position to a second position in which the wheelchair occupant is supported by the seat in a standing position without changing the center of gravity of the wheelchair, wherein the dual drive gear actuating and seat positioning means includes shift lever means for disengaging the travel gear drive system and engaging a seat positioning gear means for causing a front portion of the seat to pivot downwardly away from the occupant's body and the leg support means to be retracted backwardly away from the occupant's legs while simultaneously raising a back portion of the seat to a convenient height to support the occupants's buttocks while the occupant is in a standing position.

A manually driven wheelchair including handwheel means for manually driving the wheelchair, a seat with a front seat section pivotally connected to a back seat section, leg support means for supporting the legs and feet of the wheelchair occupant and manual seat positioning means for changing the position of the seat from a first position in which the wheelchair occupant is supported by the seat in a fully seated position to a second position in which the wheelchair occupant is supported by the seat in a standing position without changing the center of gravity, wherein the seat positioning means is manually actuated to cause said front seat section to pivot downwardly and away from the occupant's body and the leg support means to be retracted backwardly away from the occupant's legs while simultaneously raising said back seat section to a convenient height to support the occupant's buttocks while the occupant is in a standing position.

A wheelchair comprising:

(a) a travel surface contacting wheel mounted for rotation in a forward and a reverse direction;
(b) direction control gear means mounted for operative association with said travel surface contacting wheel, said direction control gear means operating in a normal operational mode to permit said surface contacting wheel to rotate in both the forward and reverse directions and in a restrictive operational mode to restrict the rotation of said surface contacting wheel in at least one direction;
said direction control gear means including a central toothed ratchet gear mounted to rotate with said travel surface contacting wheel and including a first row of teeth directed in a first direction and a second row of teeth directed in a second opposite direction, a pair of pivoted pawls mounted to engage the teeth of said toothed ratchet gear, one of said pawls being biased into engagement with said first row of teeth to prevent rotation of said ratchet gear in a clockwise direction and the other of said pawls being biased into engagement with said second row of ratchet teeth to prevent rotation of the ratchet gear in a counterclockwise direction,
(c) mode selector means operable by a wheelchair occupant to select the desired operational mode;
(d) selection transmission means connected between said direction control gear means and said mode selector means and operative to control said direction control gear means in response to the operational mode selection made by said mode selector means, and
(e) cam means operatively connected to said selection transmission means for moving one or both of said pawls out of engagement with said ratchet gear teeth in response to selections made by said mode selector means, said cam means including spaced cams and a rotatable selector plate means supporting said spaced cams, which is connected to said selection transmission means, said cams operating in response to the rotation of said selector plate means to selectively engage and remove one or both of said pivoted pawls out of engagement with said ratchet teeth, both of said pivoted pawls being left in engagement with said ratchet teeth in at least one rotational position of said selector plate means.

3 more elements

A directional control system for a wheelchair to be operatively associated with at least one of the wheels of the wheelchair and controllable by the wheelchair occupant to selectively control and restrict the travel of the wheelchair, wherein said directional control system includes:

(a) mode selector means for selecting at least four different operational modes, said modes comprising a Forward Only mode, wherein said wheelchair can be driven only in a forward travel direction;
a Reverse Only mode, wherein said wheelchair can be driven only in a reverse travel direction;
a Drive mode, wherein said wheelchair can be driven in a forward direction but is not prevented from moving in a reverse direction;
and a Park mode, wherein said wheelchair is prevented from traveling in both a forward and a reverse direction;
(b) directional control gear means adapted to be operatively geared to said at least one wheel for controlling the rotation of said wheel;
and
(c) mode selection transmission means for transmitting the selected operational mode to the directional control gear means, said directional control gear means including a toothed ratchet gear mountable for rotation with said wheelchair wheel, a pair of pivoted pawls spring biased and mountable to engage the teeth of said ratchet gear, spaced cam means operative to move said pawls out of engagement with said teeth in response to operational modes selection made by said mode selection transmission means, and rotatable selector plate means connected to said mode selection transmission means for rotation thereby, said cam means being mounted on said selector plate means, the selector plate means being mountable to position said cam means for selective engagement with said pivoted pawls.

4 more elements

A wheelchair for transporting an occupant

a structural frame;
wheelchair support wheels mounted for rotation on said frame;
seat means including an occupant supporting seat, said occupant supporting seat being articulated and including a rear section and a front section pivoted to said rear section,
mounting means associated with said frame and said seat means for mounting said seat means on said frame, said seat means including drive means mounted to drive said occupant supporting seat for movement relative to said frame between a lowermost position relative to said wheels and an uppermost position spaced above said lowermost position, said drive means including a drive mechanism for operation by said wheelchair occupant to control said drive means, said front section of said occupant supporting seat extending outwardly in a plane of said rear section in the lowermost position of said occupant supporting seat, the front section of said occupant supporting said pivoting downwardly from said rear section as said occupant supporting seat moves from the lowermost to the uppermost position;
wherein said seat means operates to move an occupant of said wheelchair between a sitting position in said lowermost position of said occupant supporting seat and a standing position in said uppermost position of said occupant supporting seat, and said seat means includes foldable leg support means movable between an extended position for supporting an occupant in a sitting position and a retracted position to facilitate support of an occupant in a standing position.

2 more elements

Dependencies are inferred from the claim text.

Wheelchair

Life of this patent

Wheelchair

Life of this patent

Abstract

Claims46