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:
Jul. 08, 1986
Filed:
Dec. 24, 1984
Ronald B Walters, Wembley, GB;
John A Hammond, Hayling Island, GB;
Vickers, Incorporated, Troy, MI (US);
Abstract
A hydraulic system in which a pilot operated hydraulic four-way main valve (11) controls the direction and rate of fluid flow to a hydraulic load (13), includes a flow sensor (15) which is capable of operating bidirectionally and may therefore be located in one of the service lines (25, 26) from the main valve (11) to the load (13). The main components of the flow sensor are a variable or fixed aperture flow sensing orifice (52, 53), and a pressure transducer (18) to which the pressure differential developed across the orifice is applied and which converts the pressure differential into an electric negative feedback signal. This electric feedback signal is compared in an electronic circuit (17) with a demand signal, and a corresponding command signal sets the pilot valve (12) which controls the main valve (11). The pressure transducer (18) in the described embodiment is a cantilever beam pressure transducer (36), acted on by the inner ends of a pair of diameter-matched sliding pins (34, 35), across the outer ends of which the pressure differential is applied.