Patient-operated wheelchair

Claim 2

A patient-operated wheel chair comprising a base structure including a pair of spaced, parallel, longitudinally extending lower support members, a pair of spaced, parallel upright support members rising from each of said lower support members and rigidly retained in spaced parallel relation, a seat assembly comprising a substantially rectangular frame having spaced, parallel side members and end members, a rigid support structure secured to each said side member of said seat frame and depending therefrom in spaced, parallel relation on the outer side, respectively, of each of said upright supporting members, guiding assemblies secured to each of said rigid support members on the inner sides thereof and coacting with an associated upright support member, the latter serving as tracks for said seat assembly, an actuator interposed between said base structure and said seat frame to effect vertical movement of the latter along said upright supporting members, a backrest assembly pivotally mounted on the rear portion of said seat assembly, a leg support assembly pivotally mounted on the front portion of said seat assembly, a pair of spaced, parallel main wheels rotatably mounted, respectively, on opposite sides of said base structure, and a pair of spaced, parallel caster wheels mounted, respectively, on opposite sides of said base structure and longitudinally spaced from said main wheels.

Claim 3

The combination set forth in claim 1 in which an additional upright support member rises from each of said lower support members between the associated pair of upright support members, the additional support members being transversely aligned, each of said additional support members rotatably mounting an associated main wheel.

Claim 4

The combination set forth in claim 1 in which an armrest is mounted on each of said side members, independent actuator means associated respectively with said backrest assembly and said leg support assembly to effect movement thereof, a fluid reservoir and a pump carried by said chair, control valve means mounted on one of said armrests, said control valve means, said fluid reservoir and said pump being connected in circuit with said actuators, whereby upon setting of an associated valve and actuation of said pump a desired actuator can be energized.

Claim 5

The combination set forth in claim 3 in which each of said rigid support structures comprises a plate depending from the associated side member, said pump is manually operated having a control Handle, said fluid reservoir and said pump being mounted on one of said sideplates, said pump handle being positioned outwardly of an associated armrest adjacent the control valve means mounted thereon.

Claim 6

The combination set forth in claim 1 in which each of said guiding assemblies comprises two pairs of vertically aligned rollers, each of said pairs of rollers straddling an associated support member.

Claim 7

The combination set forth in claim 5 in which each of said upright support members is a length of rigid tubing, each roller having an annular groove in its periphery of configuration conforming to the curvature of the upright support member and positioned closely adjacent thereto whereby said seat frame will move vertically with substantially no longitudinal or transverse play.

Claim 8

The combination set forth in claim 5 in which each of said guiding assemblies comprises a substantially U-shaped bracket having a crosspiece and a pair of parallel legs each having an outwardly extending flange at the end thereof, means securing said flanges to said rigid supporting member adjacent the lower end thereof, two pairs of vertically aligned stud shafts extending between said rigid supporting member and the crosspiece of each of said brackets, each of said stud shafts carrying an associated roller.

Claim 9

The combination set forth in claim 1 in which a support member extends transversely between said lower support members of said base structure, a support member extends transversely between the side members of said seat frame vertically aligned with said first transverse support member and said actuator extends between said transverse support members and is secured at each end thereto respectively to effect vertical movement of said seat assembly.

Claim 10

The combination set forth in claim 8 in which the actuator for said seat assembly comprises a cylinder having a piston rod slidably mounted therein, said cylinder being connected to one of said transverse support members and said piston rod being connected to the other of said transverse support members.

Claim 11

The combination set forth in claim 8 in which the actuator for said seat assembly comprises an elongated casing secured at one end to one of said support members and a screw member rotatably mounted in said casing, a motor rigidly secured to the other transverse support member and operatively connected to said screw to rotate the latter.

Claim 12

A patient-operated wheelchair comprising a base structure, a seat assembly secured to said base structure, a backrest assembly pivotally mounted on the rear portion of said seat assembly, a leg support assembly pivotally mounted on the front portion of said seat assembly, said back and leg assemblies being shiftable into coplanar alignment with said seat assembly, a pair of spaced, parallel main wheels rotatably mounted, respectively, on opposed sides of said base structure, a first pair of spaced, parallel caster wheels mounted, respectively, on opposite sides of said base structure forwardly spaced from said main wheels, a second pair of spaced, parallel caster wheels mounted, respectively on opposite sides of said base structure and spaced rearwardly of said main wheels, the lowermost peripheries of said second pair of caster wheels being located in a common plane above the plane tangent to the lowermost peripheries of said main wheels and said first pair of caster wheels, whereby said chair will be supported selectively on said main and first pair of caster wheels when the center of gravity is forward of the axes of said main wheels, and on said main wheels and said second pair of caster wheels when the center of gravity is rearward of said axes, said backrest assembly comprises a pair of upstanding support members, trunnion means pivotally mounting each of said support members to the rear end of said seat assembly, means rigidly retaining each of said support members in spaced parallel relation, a pair of pivot mounts rigidly secured to said seat assembly and extending rearwardly of said tRunnion means, said mounts being operatively associated respectively with said trunnion means, and a pair of elongated actuating members, each being pivotally secured at one end to an associated pivot mount and at its other end to an associated backrest support member at a point thereon vertically spaced from the pivotal mount whereby upon energization of said actuating members, said backrest may be moved between vertical and horizontal position.

Claim 13

A patient-operated wheelchair comprising a base structure, a seat assembly secured to said base structure, a backrest assembly pivotally mounted on the rear portion of said seat assembly, a leg support assembly pivotally mounted on the front portion of said seat assembly, said back and leg assemblies being shiftable into coplanar alignment with said seat assembly, a pair of spaced, parallel main wheels rotatably mounted, respectively, on opposed sides of said base structure, a first pair of spaced, parallel caster wheels mounted, respectively, on opposite sides of said base structure forwardly spaced from said main wheels, a second pair of spaced, parallel caster wheels mounted, respectively on opposite sides of said base structure and spaced rearwardly of said main wheels, the lowermost peripheries of said second pair of caster wheels being located in a common plane above the plane tangent to the lowermost peripheries of said main wheels and said first pair of caster wheels, whereby said chair will be supported selectively on said main and first pair of caster wheels when the center of gravity is forward of the axes of said main wheels, and on said main wheels and said second pair of caster wheels when the center of gravity is rearward of said axes, said backrest assembly comprises a pair of upstanding support members, trunnion means pivotally mounting each of said support members to the rear end of said seat assembly, means rigidly retaining each of said support members in spaced parallel relation, a pair of pivot mounts rigidly secured to said seat assembly and extending rearwardly of said tRunnion means, said mounts being operatively associated respectively with said trunnion means, and a pair of elongated actuating members, each being pivotally secured at one end to an associated pivot mount and at its other end to an associated backrest support member at a point thereon vertically spaced from the pivotal mount whereby upon energization of said actuating members, said backrest may be moved between vertical and horizontal position.