Patents by Inventor Carl F. Drake

Carl F. Drake has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5941547
    Abstract: A manually propelled wheelchair (10) powered by the chair occupant. Hand power levers (11,12) are pivoted on each side of the chair frame (15). Drive cables (25) connect each lever to a wheel pulley (20) which in turn acts through one-way clutches to propel the wheels (16, 17) during the power stroke as the lever pulls the drive cable. The clutches permit free wheeling of the chair except during the application of drive power. Recoil springs (46) rewind the cable on the pulley during the lever's return stroke. The point of cable attachment (19) to the lever is changed by rotating the lever handle (21) to change the ratio of lever movement to wheel movement. Moving the attachment point below the pivot point reverses the direction of the power and the return strokes. Directional control is obtained by differential application of power to the wheels and by selective wheel braking. For single hand operation, a single axle is used for both wheels.
    Type: Grant
    Filed: January 16, 1996
    Date of Patent: August 24, 1999
    Inventor: Carl F. Drake