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. 13, 1988
Filed:
Nov. 03, 1987
Steven H Johnson, Dubuque, IA (US);
Deere & Company, Moline, IL (US);
Abstract
A large industrial earthmoving machine having a hydraulic propulsion system comprising at least two hydraulic motors which are powered from a source of hydraulic fluid to drive a common load. Each motor of the hydraulic propulsion system is provided with two compensating valve assemblies. Each compensating valve assembly is provided with a compensating spool and a shuttle spool to provide accurate control of the hydraulic motors. In each pair of compensating valve assemblies, there is a forward compensating valve assembly and a backward valve assembly respectively controlling forward and backward movement of the hydraulic motor. Between the both forward compensating valve assemblies and the respective hydraulic motors, the compensating valve assemblies are fluidically coupled to one another by a small hydraulic communication line that better equalizes hydraulic fluid flow to the motors and prevents domination of one forward compensating valve assembly over the other. Similarly, the backward compensating valve assemblies are provided with an identical small hydraulic communication line accomplishing the same results.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile