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:
Sep. 03, 1991
Filed:
Aug. 31, 1990
Fred A Topham, Kingston, Ontario, CA;
Joseph A Toth, Unionville, Ontario, CA;
Michael F Wilson, Toronto, Ontario, CA;
Other;
Abstract
A valve is provided preferably having a moulded plastic valve plug with a plurality of preferably arcuate grooves circumferentially spaced in the forward surface of the plug. The arcuate grooves distribute fluid flowing between the plug and valve seat substantially equally about the periphery of the valve plug. Fluid is also directed by the grooves to flow between a sealing surface of the plug and the valve seat in an outward radial direction substantially parallel to the valve seat. The resulting fluid flow reduces cavitation, valve stem chatter, noise and vibrations as well as reducing erosiion of the valve seat. An inner portion of the plug is made of a relatively high tensile strength material having a low thermal expansion rate whereas an outer portion of the plug including the plug sealing surface is made of a material having a relatively low surface hardness. The result is that the inner portion having the arcuate grooves remains relatively dimensionally stable whereas the outer portion resiliently seals upon the valve seat. A method of moulding the inner and outer portions of the plastic valve plug upon the valve stem is also provided.