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, 2003
Filed:
May. 02, 2001
Marty Pierce, North Royalton, OH (US);
Matthew John Plas, Elyria, OH (US);
Abstract
A control valve and feedback system has three operating states including a lifting state, a neutral state, and a lowering state. The feedback control system comprises a cylinder, a pump, a reservoir for holding working fluid, and a control valve. The control valve comprises a valve body having first and second ends with a bore defined therebetween. The valve body further comprises an inlet port, a return port, a first work port and a second work port. The inlet port, return port, and first and second work ports are defined in the valve body. The inlet port communicates with the bore and the pump. The return port is in fluid communication with the bore and the reservoir. The first work port is also in communication with the bore and the cylinder in the lifting state. The control valve is plumbed backwards so that the first work port and the second work port are in fluid communication in the lowering state. The valve also comprises a check valve disposed in the first work port. The first check valve is adapted to achieve the neutral state and being selectively adjustable to achieve said lowering state.