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:
Feb. 19, 1980
Filed:
Jan. 13, 1978
Applicant:
Inventor:
Karlmann Hamma, Tettnang, DE;
Assignee:
Zahnradfabrik Friedrichshafen AG, Friedrichshafen, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
F16H / ;
U.S. Cl.
CPC ...
60444 ; 60488 ; 60494 ;
Abstract
A hydrostatic transmission having a variable displacement pump whose control element varies the transmission ratio and output direction of the transmission is controlled by a hydraulic servomechanism including a direction-reversing valve and a cylinder connected to this valve. A direction selector acts upon the valve and a mechanical or hydraulic locking mechanism is provided to prevent shifting of the valve until the control element of the pump has been restored to its neutral position before direction change.