Stair-climbing wheel chairs

Claim 1

AN OCCUPANT PROPELLED AND CONTROLLED OBSTRUCTIONCLIMBING WHEEL CHAIR COMPRISING A PAIR OF SIDE FRAMES SUSTAINED IN SPACED RELATIONSHIP BY LATERAL STRUCTURE, SAID STRUCTURE FORMING A CHAIR COMPRISING A SEAT, A BACK AND A FOOT REST, A DRIVE WHEEL ROTATIVELY MOUNTED IN FIXED POSITION ON EACH SIDE FRAME AT THE FRONT OR FOOT REST END OF SAID CHAIR, A SWIVEL WHEEL POSITIONED TO THE REAR OF EACH DRIVE WHEEL AND PIVOTLY MOUNTED TO THE RESPECTIVE SIDE FRAME, EACH SWIVEL BEING DISPOSED TO BE PIVOTED OUT OF NORMAL POSITION TO FACILITATE OBSTRUCTION CLIMBING, MEANS DISPOSED TO BE OPERATED BY THE OCCUPANT OF THE CHAIR TO EFFECT AND CONTROL THE PIVOTING OF THE SWIVEL WHEELS, A TRACTION BELT DEVICE COMPRISING A FRAME CARRYING A PLURALITY OF ROTATABLE MEMBERS IN SPACED RELATIONSHIP WITH AN ENDLESS BELT OPERATING THEREOVER PIVOTLY MOUNTED IN FIXED POSITION IN EACH SIDE FRAME BY A LATERAL EXTENSION OF THE REAR ROTATABLE MEMBER EXTENDING INTO THE FRAME STRUCTURE AT THE REAR THEREOF, EACH TRACTION DEVICE FRAME STRUCTURE EXTENDING UNDER SAID CHAIR AND THE FORWARD END OF EACH BEING CONNECTED TO OPERATING MEANS ATTACHED TO EACH SIDE FRAME, RESPECTIVELY, SAID MEANS BEING DISPOSED TO BE OPERATED BY THE OCCUPANT OF THE CHAIR TO RAISE THE FORWARD END OF THE RESPECTIVE TRACTION DEVICE OUT OF CONTACT WITH SURFACES ON WHICH THE SAID WHEELS WOULD NORMALLY OPERATE AND TO LOWER THE SAID END OF THE DEVICES TO CONTACT SAID SURFACES AND THEREBY EFFECT RAISING THE FRONT OF THE CHAIR TO RAISE THE DRIVE WHEELS OUT OF CONTACT WITH SURFACES AS SET FORTH, INDEPENDENT DRIVE MEANS CONNECTING EACH DRIVE WHEEL WITH EACH TRACTION DEVICE, RESPECTIVELY, MEANS TO ENGAGE AND DISENGAGE EACH SAID DRIVE MEANS, MEANS TO CHECK THE MOVEMENT OF EACH TRACTION BELT IN BOTH DIRECTIONS WHENEVER THE RESPECTIVE DRIVE WHEEL IS AT REST, SAID MEANS BEING SUCH AS TO EFFECT MOVEMENT OF THE BELTS IN ACCORDANCE WITH ANY ROTATION OF THE RESPECTIVE DRIVE WHEELS THAT MAY BE EFFECTED BY THE OCCUPANT OF THE CHAIR.