Stair-climbing hand truck
AssigneeUltra Lift Corporation
InventorsErcel W. McPeak, Theodore Felzer, Frederick J. Rodgers
Life of this patent
Estimating the term…
Abstract
A hand truck for powered raising and lower of an extremely heavy load comprises first and second frame members constructed of aluminum and mounted for relative longitudinal reciprocating movement. One of the members has a lip attached thereto for positioning the load thereon. The frame members are coupled by means for actuating the relative longitudinal movement. The actuation means is powered by a selectively engageable electric motor. Overload release clutch means is interposed between the motor and the actuation means to decouple the motor and actuation means whenever the load exceeds a predetermined amount.
Claims4
A hand truck for powered raising and lowering of a heavy load comprising:
- first and second aluminum frame members formed in a unitary construction of extruded aluminum and mounted for relative longitudinal reciprocating movement between two stop points, said first member having a lip attached thereto for positioning a load thereon;
- actuation means coupled to said frame members for actuating relative longitudinal movement thereof, said actuation means being powered by a selectively engageable electric motor;
- overload release clutch means coupling said motor and said actuation means for raising and lowering a load positioned by said lift on said frame members, said overload release clutch means decoupling said motor and said actuation means whenever said load exceeds a predetermined amount of at least about 1000 pounds and also whenever said frame members reach said stop points;
- and
- said an audible warning sound whenever said load exceeds said predetermined amount and whenever said frame members reach said stop points.
Dependencies are inferred from the claim text.