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:
Dec. 21, 1993
Filed:
Jan. 11, 1993
Jeffrey C Hansell, Ames, IA (US);
Sauer Inc., Ames, IA (US);
Abstract
An automotive control system for hydrostatic pumps includes a hydraulic circuit with an automotive orifice located upstream of the main hydrostatic loop with replenishing check valves and downstream of the fill pump. The location of the automotive orifice upstream of the check valves isolates system leakage from affecting flow to the automotive orifice. A hydrostatic unit displacement control valve has a drain side connected to the hydraulic circuit downstream of the fill pump and in parallel with the automotive orifice, and has a supply side connected downstream of the automotive control orifice. The input logic of the control valve is reversed to compensate for the greater pressure available to the drain side of the control valve as compared to the supply side. Reversing the input logic of the control valve provides servo control pressures without the need to isolate the control supply from the hydrostatic loop supply.