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:
May. 26, 1998
Filed:
Nov. 28, 1995
Dallas W Simonette, Andover, MN (US);
GP Companies, Inc., Mendota Heights, MN (US);
Abstract
An unloader valve for a high pressure pumping system is disclosed. The unloader valve diverts fluid back to the pump inlet when the discharge line is blocked, and directs flow to the pump outlet when the line is unblocked. The unloader valve includes a valve body with a central cavity, a bypass check valve which also functions as a pressure relief valve, a shuttle positioned in the central cavity and a discharge check valve. A spring in the bypass check valve holds the bypass check valve closed while the system is in the spray mode. The discharge check valve closes when the line is blocked, and the line pressure is trapped between the discharge check valve and the spray gun. When the gun is reactivated, the pressure trapped behind the discharge check valve moves the shuttle forward, which opens the bypass valve.