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:
Aug. 02, 1994
Filed:
Mar. 02, 1993
Werner Hormann, Illertissen, DE;
Manfred Blum, Weissenhorn, DE;
Hydromatik GmbH, Elchingen, DE;
Abstract
The invention relates to a power control device for two variable displacement pumps, each with an adjusting device which can be acted upon by adjusting pressure, a power control valve associated therewith, which is acted upon by a first control pressure corresponding with the operating pressure of the variable displacement pump to be adjusted against a pressure difference in the direction of the control position, in which the adjusting pressure loading is controlled in the direction of reduced displacement of the variable displacement pumps along a hyperbolic control curve, whereby the pressure difference results from a spring-arrangement backpressure counteracting the first control pressure and a second control pressure corresponding with the operating pressure of the other variable displacement pump and with increase of the same drops from a maximum value to a minimum value. In order to set the latter value with the device, it is provided in accordance with the invention that the spring arrangement comprises a first and a second pressure spring, the first pressure spring is set to a force corresponding with the minimum value (.DELTA.p.sub.min) and the second pressure spring is set to a force corresponding with the difference (.DELTA.p.sub.max -.DELTA.p.sub.min) between maximum value (.DELTA.p.sub.max) and minimum value (.DELTA.p.sub.min) of the pressure difference, and the first pressure spring with its setting force and the second pressure spring with a force decreasing with increasing second control pressure act upon the power control valve.