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:
Jan. 29, 1985
Filed:
Dec. 03, 1982
Martin J Fisher, Milton Keynes, GB;
Roger A Heron, Stagsden, GB;
Martin L Hughes, Newport Pagnell, GB;
National Research Development Corporation, London, GB;
Abstract
A device for determining the level of particulate contamination in a hydraulic system. Between the inlet and outlet of the device the fluid passes through the narrow clearance between a piston and a surrounding bore. As the clearance becomes obstructed by contaminant, pressure rises in a chamber upstream of the piston. Rise of this pressure above a certain level is detected by a detector which both triggers a counter and operates a solenoid to withdraw the piston and release trapped contaminant, after which the piston returns and another cycle of contaminant build-up begins. The frequency of the release of the piston indicates the degree of contamination of the fluid. Instead of pressure build-up, parameters related to fluid flow may be used to trigger the counter and the release of contaminants from clearance, and means may be provided to meter individual, fixed-volume charges from the general body of fluid and discharge them through a clearance. The clearance may as an alternative be arranged to be cleared by back flushing.