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. 11, 1999
Filed:
Jan. 09, 1997
Herb Hoenisch, Waukesha, WI (US);
Robert D Kern, Waukesha, WI (US);
Gerald C Ruehlow, Oconomowoc, WI (US);
Wes Sodemann, Dousman, WI (US);
Fred Yang, Wauwatosa, WI (US);
Generac Portable Products, LLC, Jefferson, WI (US);
Abstract
A pressure washer is powered by a prime mover, e.g., an electric motor or an internal combustion engine, and has a flow control valve. The valve has a housing containing a piston assembly and the assembly has a mechanism coupled to it for controlling prime mover power. The piston assembly includes a first piston sealing against the housing and dividing the housing interior into two chambers. Such first piston is spring-biased to a first position during periods when no output flow is being demanded from the washer. The assembly also has a second piston spring-biased to seal against the first piston during periods of no flow. When flow is demanded by opening the nozzle, the pressure in the second chamber diminishes. And when the difference between the pressure in the second chamber and that in the first chamber exceeds a predetermined value, the assembly shifts to a second position, causing the mechanism to actuate the prime mover.