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:
Sep. 20, 1977
Filed:
Nov. 17, 1976
Kenneth F Golan, Pekin, IL (US);
James E Winzeler, East Peoria, IL (US);
Caterpillar Tractor Co., Peoria, IL (US);
Abstract
A control for a hydraulically operated winch or the like having a hydraulically disengaged brake, a multi-speed, hydraulically controlled transmission, and a drum to be driven or braked. The control system includes means whereby the transmission is placed in neutral, automatically, whenever the brake is to be disengaged to lower a load and a control valve including a spool with small and large slots along with a drum-driven metering pump controls fast and slow lowering speeds. Emergency free fall of the load is accomplished in the valve by bypassing the small metering slot. An arrangement of an accumulator and check valves allow hydraulic disengagement of the brake even if the engine is dead and there is provided a recirculating hydraulic circuit to conserve oil in such an instance so that the accumulator volume can be minimized. A system is included whereby the accumulator may be discharged, when the prime mover is inoperative to allow the operator of the winch to leave the location with the load suspended with the knowledge that the load cannot be lowered either intentionally or accidentally.