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:
Apr. 26, 1977
Filed:
Dec. 30, 1975
Stanley W Crull, Ames, IA (US);
Sundstrand Corporation, Rockford, IL (US);
Abstract
A synchronous control system for a pair of hydrostatic transmissions and more particularly a drive for a vehicle using a pair of hydrostatic transmissions with each driving a propulsion member and a straight tracking control therefor, with the system having a pair of pressure-responsive displacement controls, associated one with each transmission and pressure lines connected thereto for providing a control pressure signal which is applied to a displacement control. A rotary valve with a pair of relatively rotatable valve members connected one to each of the two transmissions for rotation proportional to the output speed of the transmissions and connected into said pressure lines and having port means which have their relation varied, dependent upon a displacement in the position of one valve member with respect to the other to connect a pressure line to a sump and thereby modify the control pressure in said last-mentioned pressure line, to result in modifying the speed of one transmission and bring the two transmissions back to synchronized speed.