Flow control valve for a pressure washer
US5902094A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 9, 1997 |
| Grant date | May 11, 1999 |
| Priority date | — |
| Expiry date | Jan 9, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/7937
- WIPO fieldChemical engineering
- WIPO sectorChemistry
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.