Seat-lift wheelchair

A retrofit kit for a wheelchair having a pair of side frame members, to convert same into a seat-lift wheelchair, said kit comprising:

• first and second mounting plates attachable to respective side frame members;
• first and second seat side support members pivotally connected to respective mounting plates;
• first and second springs connected between respective mounting plates and seat side support members for mechanically raising said seat and an occupant seated therein from a sitting position to an up-right position;
• seat-lift control means for controlling the rate of ascent and descent of said seat, and for stopping said seat between its sitting and up-right positions.

A seat-lift wheelchair, comprising:

• a pair of side frame members;
• a generally planar and generally vertical back connected between said frame members;
• a generally planar seat having first and second side support members pivotally connected to respective side frame members;
• first and second drive wheels rotatably connected to respective side frame members;
• first and second support wheels rotatably mounted on respective side frame members;
• and
• seat-lift means mounted with said frame members and with said seat for mechanically raising said seat and an occupant seated therein from a sitting position to an up-right position, said seat-lift means comprising
• first and second springs connected between respective side frame members and respective seat side support members;
• and
• manually controllable lift control means for controlling the rate of ascent and descent of said seat, and for stopping said seat between the sitting position and the up-right position, said lift control means comprising a closed-loop hydraulic system comprising first and second hydraulic cylinders mounted between respective side frame members and seat side support members, and liquid control means for manually controlling the rate of extension and retraction of said hydraulic cylinders, and for controlling the amount of extension of said hydraulic cylinders, said liquid control means comprising
• a liquid control valve in communication with said hydraulic cylinders for controlling and interrupting liquid flow through said hydraulic cylinders, and
• a liquid flow rate control valve in communication with said hydraulic cylinder for controlling the rate of liquid flow through said hydraulic cylinders.

A seat-lift wheelchair, comprising:

• a pair of side frame members;
• a generally planar and generally vertical back connected between said frame members;
• a generally planar seat having first and second side support members pivotally connected to respective side frame members;
• first and second drive wheels rotatably connected to respective side frame members;
• first and second support wheels rotatably mounted on respective side frame members;
• and
• seat-lift means mounted with said frame members and with said seat for mechanically raising said seat and an occupant seated therein from a sitting position to an up-right position, said seat-lift means comprising
• first and second coiled tension springs, each connected between a respective side frame member and seat side support member via a cam mechanism that permits gradual decrease of the torque applied to respective seat side support members as said seat is urged from its sitting position to its up-right position;
• and
• manually controllable lift control means for controlling the rate of ascent and descent of said seat, and for stopping said seat between the sitting position and the up-right position.

A retrofit kit for a wheelchair having a pair of side frame members, to convert same into a seat-lift wheelchair, said kit comprising:

• first and second mounting plates attachable to respective side frame members,
• first and second seat side support members pivotally connected to respective mounting plates,
• first and second springs connected between respective mounting plates and seat side support members,
• seat-lift controls means for controlling the rate of ascent of said seat, and for stopping said seat between its sitting and up-right positions, said lift control means comprising a closed-loop hydraulic system comprising first and second hydraulic cylinders mounted between respective mounting plates and seat side support members, and liquid control means for manually controlling the rate of extension and retraction of said hydraulic cylinders, and for controlling the amount of extension of said hydraulic cylinders, said liquid control means comprising
• a liquid control valve in communication with said hydraulic cylinders for controlling and interrupting liquid flow through said hydraulic cylinders;
• and
• a liquid flow rate control valve in communication with said hydraulic cylinder for controlling the rate of liquid flow through said hydraulic cylinders.

A retrofit kit for a wheelchair having a pair of side frame members, to convert same into a seat-lift wheelchair, said kit comprising:

• first and second mounting plates attachable to respective side frame members,
• first and second seat side support members pivotally connected to respective mounting plates,
• first and second coiled tension springs, each connected between a respective mounting plate and seat side support member via a cam mechanism that permits gradual decrease of the torque applied to respective seat side support members as said seat is urged from its sitting position to its up-right position,
• seat-lift controls means for controlling the rate of ascent of said seat, and for stopping said seat between its sitting and up-right positions.

A seat-lift wheelchair, comprising:

• a pair of side frame members;
• a generally planar and generally vertical back connected between said frame members;
• a generally planar seat having first and second side support members pivotally connected to respective side frame members;
• first and second drive wheels rotatably connected to respective side frame members;
• first and second support wheels rotatably mounted on respective side frame members;
• and
• seat-lift means mounted with said frame members and with said seat for mechanically raising said seat and an occupant seated therein from a sitting position to an up-right position, said seat-lift means comprising:
• first and second torsion axles mounted to respective seat side support members;
• and
• first and second torsion springs, each adjustably connected to a respective side frame member at one end thereof, and to a respective torsion axle at the other end thereof;
• and
• manually controllable lift control means for controlling the rate of ascent and descent of said seat, and for stopping said seat between the sitting position and the up-right position.

A seat-lift wheelchair, comprising:

• a pair of side frame members;
• a generally planar and generally vertical back connected between said frame members;
• a generally planar seat having first and second side support members pivotally connected to respective side frame members;
• first and second drive wheels rotatably connected to respective side frame members;
• first and second support wheels rotatably mounted on respective side frame members;
• seat-lift means mounted with said frame members and with said seat for mechanically raising said seat and an occupant seated therein from a sitting position to an up-right position, said seat-lift means comprising first and second coiled compression springs, each adjustably connected to a respective side frame member at one end thereof and to a respective seat side support member at the other end thereof;
• and
• manually controllable lift control means for controlling the rate of ascent and descent of said seat, and for stopping said seat between the sitting position and the up-right position.

A seat-lift wheelchair, comprising:

• a pair of side frame members;
• a generally planar and generally vertical back connected between said frame members;
• a generally planar seat having first and second side support members pivotally connected to respective side frame members;
• first and second drive wheels rotatably connected to respective side frame members;
• first and second support wheels rotatably mounted on respective side frame members;
• seat-lift means mounted with said frame members and with said seat for mechanically raising said seat and an occupant seated therein from a sitting position to an up-right position, said seat-lift means comprising first and second coiled tension springs, each connected between a respective side frame member and seat side support member via a cam mechanism that permits gradual decrease of the torque applied to respective seat side support members as said seat is urged from its sitting position to its up-right position;
• and
• manually controllable lift control means for controlling the rate of ascent and descent of said seat, and for stopping said seat between the sitting position and the up-right position.

A retrofit kit for a wheelchair having a pair of side frame members, to convert same into a seat-lift wheel chair said kit comprising:

• first and second mounting plates attachable to, respective side frame members;
• first and second seat side support members pivotally connected to respective mounting plates;
• first and second torsion axles mounted to respective seat side support members;
• first and second torsion springs, each adjustably connectable to respective side frame member at one end thereof and to a respective torsion axle at the other end thereof;
• and
• seat-lift control means for controlling the rate of ascent and descent of said seat, and for stopping said seat between a sitting position and an up-right position.

A retrofit kit for a wheelchair having a pair of side from members, to convert same into a seat-lift wheelchair, said kit comprising:

• first and second mounting plates attachable to respective side frame members;
• first and second seat side support members pivotally connected to respective mounting plates;
• first and second coiled compression springs, each adjustably connectable to a respective side frame member at one end thereof and to a respective seat side support member at the other end thereof;
• and
• seat-lift control means for controlling the rate of ascent and descent of said seat, and for stopping said seat between a sitting position and an up-right position.

A retrofit kit for a wheelchair having a pair of side frame members, to convert same into a seat-lift wheelchair, said kit comprising;

• first and second mounting plates attachable to respective side frame members;
• first and second seat side support members pivotally connected to respective mounting plates;
• first and second coiled tension springs, each connectable between a respective side frame member and seat side support member via a cam mechanism that permits gradual decrease of the torque applied to respective seat side support members as said seat is urged from a sitting position to an up-right position;
• and
• seat-lift control means for controlling the rate of ascent and descent of said seat, and for stopping said seat between the sitting position and the up-right position.