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:
Mar. 18, 2008
Filed:
Apr. 15, 2005
Steven R. Pride, Ii, Schoolcraft, MI (US);
Charles J. Bowden, Battle Creek, MI (US);
Steven R. Pride, II, Schoolcraft, MI (US);
Charles J. Bowden, Battle Creek, MI (US);
Fema Corporation of Michigan, Portage, MI (US);
Abstract
A proportional pressure control valve which includes an electric first stage pilot having a single outlet port configured to provide a variable pressurized hydraulic fluid to the outlet port and at a pressure that is proportional to an electric input signal and which is variable between first and second values and further includes a second stage hydraulic valve which has a spool reciprocally moveable in a bore between first and second positions indicative of a full ON and a full OFF condition. A fluid isolation chamber is oriented in the bore and in a region between a control port and a tank port in the fluid pathway therebetween. The interior wall of the bore and the first and second diameter regions on the spool are configured to always provide a controlled volume fluid flow rate between the control port and the fluid isolation chamber.