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. 31, 1995
Filed:
Jan. 28, 1994
Gordon M Smith, Brookshire, TX (US);
Johnston Pump/General Valve, Inc., Brookshire, TX (US);
Abstract
Fluid pressure changes are imposed on selected interior surfaces of a plug passageway of a plug valve to create torque. In one embodiment perturbations are provided in selected flow surfaces of the valve plug to create turbulent boundary layer flow along such surfaces which generates a beneficial stabilizing torque tending to reduce or eliminate holding forces conventionally provided by mechanical parts such as detent mechanisms. In another embodiment, pilot holds between interior and exterior plug surfaces are used to alter the fluid pressure at diagonally opposite locations relative to the plug rotation axis to produce the stabilizing torque.