The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 28, 1978
Filed:
Dec. 30, 1975
Harvey E Schmidt, Chicago Heights, IL (US);
Luke F Henry, Homewood, IL (US);
Howard G Murphy, Greendale, WI (US);
Thomas P Gilmore, Wauwatosa, WI (US);
Allis-Chalmers Corporation, Milwaukee, WI (US);
Abstract
A chopper motor-controller for regulating a lift truck traction motor incorporates means for detecting faults which may cause the truck to run out of control, such as the high speed bypass contacts which shunt the semiconductor power switch being welded closed, and for disabling the controller in response thereto and also has time delay means for preventing a directional contactor from closing in on a fault before the fault detecting means can operate to disable the controller. The disclosed controller may alternatively be connected to require the operator to relax the accelerator foot pedal when starting or changing direction or to permit change of direction while the foot pedal is depressed.