Stair climbing wheel chair

Claim 1

A WHEEL CHAIR COMPRISING IN COMBINATION, (A) A PAIR OF WHEELS ROTATABLY AND RETRACTABLY MOUNTED ON THE CHAIR FOR SUPPORTING THE SAME WHEN TRAVELING ON SUBSTANTIALLY LEVEL GROUND, (B) FRONT AND REAR RESTS ON SAID CHAIR FOR SUPPORTING SAID CHAIR IN A SUBSTANTIALLY NORMAL POSITION ON A WALKING SURFACE, SUCH AS STAIRS, WHEN SAID WHEELS ARE RETRACTED, (C) A PAIR OF FRONT LEGS PIVOTALLY MOUNTED ADJACENT THE FRONT OF SAID CHAIR, (D) A PAIR OF REAR LEGS PIVOTALLY MOUNTED ADJACENT THE REAR OF SAID CHAIR, (E) EACH OF SAID LEGS BEING MOUNTED TO SWING FORE-ANDAFT OF THE CHAIR AND BEING EXTENDIBLE LENGTHWISE FOR ENGAGEMENT OF ITS FREE END WITH SAID WALKING SURFACE, (F) DRIVE MEANS CONNECTED BETWEEN SAID CHAIR AND AT LEAST ONE OF SAID LEGS FOR PIVOTING THE SAME, (G) POWER MEANS FOR EXTENDING SAID LEGS AND FOR ACTUATING SAID DRIVE MEANS SUCH THAT SAID CHAIR CAN BE RAISED OFF SAID FRONT AND REAR RESTS AND MOVED FORWARD OR BACK, AND (H) MEANS FOR CONTROLLING SAID POWER MEANS SUCH THAT THE OCCUPANT OF THE CHAIR CAN SEQUENTIALLY RAISE THE CHAIR ON SAID LEGS, MOVE IT FORWARD OR BACK WHILE SUPPORTED ON SAID LEGS, AND LOWER THE CHAIR ONTO SAID RESTS.