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:
Aug. 07, 1984
Filed:
Oct. 23, 1981
Willy Holdenried, Friedrichshafen, DE;
Zahnradfabrik Friedrichshafen, A.G., Friedrichshafen, DE;
Abstract
A hydrostatic transmission between a prime mover and a load, e.g. for driving an automotive vehicle, especially an automotive vehicle requiring a high degree of maneuverability such as a fork lift truck, comprises a reversible-output variable displacement pump connected to a motor which, in turn, drives the load. The control element of the pump is operated by a hydraulic piston-and-cylinder arrangement biased into a neutral position between positions of forward and reverse operation of the pump and pressurization of the oppositely effective chambers in this arrangement is controlled by a pedal-operated 'inch' valve whose flow cross section progressively increases with pedal actuation and controls the return of the pressure medium to the reservoir. The valve is designed so that even when the prime mover operates at high speed, starting movements of the pedal provide sensitive movement of the vehicle.