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:
Apr. 07, 1992
Filed:
Apr. 12, 1991
Brian K Davis, Tempe, AZ (US);
Marshall U Hines, Scottsdale, AZ (US);
Larry K Ball, Chandler, AZ (US);
Stephan R Cronenberg, Mesa, AZ (US);
Allied-Signal Inc., Morris Township, Morris County, NJ (US);
Abstract
A flow modulator (48) for a butterfly valve (40) incorporates a first protrusion (64) on the high-pressure side (52) of the modulator and a second protrusion (66) on the low-pressure side (54). The second protrusion (66) is spaced from the leading edge (60) to define a surface portion (88) of the low-pressure side (54). In operation, the second protrusion (66) functions as a flow restrictor that increases pressure in a region (86) of the flow path (44) bordered in part by the second protrusion and the surface portion (88). This increase in pressure serves to minimize the net aerodynamically-induced closing torque exerted on the modulator (46). The height of the second protrusion and its distance from the leading edge are shown to be important design parameters. In addition, the use of a third protrusion (114) for reducing torque drop-off at high rotational angles is disclosed.