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. 27, 1977
Filed:
Feb. 24, 1977
William D McMillan, Joliet, IL (US);
Caterpillar Tractor Co., Peoria, IL (US);
Abstract
A hydraulic system for controlling the displacement of a plurality of variable displacement pumps driven by a single prime mover including a source of pilot fluid under pressure including a fixed displacement pump adapted to be driven by the prime mover proportional to the speed thereof, a double-piloted, underspeed valve having an inlet and an outlet, the outlet being adapted to be connected to the variable displacement pumps for controlling displacement thereof, a conduit connecting one of the pilots to the source, an additional conduit, including a flow restricting device, connecting the other of the pilots to the source, and a summing valve having ports adapted to be connected to respective ones of the pumps, a port connected to the second conduit and a port connected to the inlet of the underspeed valve.