Patent 4142732 Issued on March 6, 1979. Estimated Expiration Date: August 23, 1997. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
Disclosed herein is an improved hand truck having stair climbing capabilities of the general type employing a pair of star-like plates journaled on a main axle and carrying a plurality of stub axles on the projecting legs of the plate with each axle carrying a wheel to facilitate ascending or descending stairs. The type of truck in question operates so that one of the wheels will be in contact with the lands of two adjacent steps at all times to avoid jarring and to facilitate movement. The improvement disclosed includes the provision of braking means which will prevent "free-wheeling" of the plate so as to effectively slow up movement of the truck particularly when descending. The brake is operated from the handle end of the truck and releasably engages the main axle to either permit or prevent "free-wheeling" of the star-like plates to thereby selectively inhibit movement of the truck.