Bypass mode control for high pressure washing system
US5035580A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 14, 1989 |
| Grant date | Jul 30, 1991 |
| Priority date | — |
| Expiry date | Sep 14, 2009 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB08B2203/027
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A pressure washing system is disclosed which consists of a hydraulic pump driven by a variable speed internal combustion engine, a nozzle gun connected to the pump outlet, an unloader valve that senses the demand state of the nozzle gun for delivering water under pressure to the gun on demand, and for recirculating water to the pump inlet when the gun is in a non-demand position, and a throttle control device. The throttle control device senses pump outlet pressure and controls engine speed as a function of the demand/non-demand mode of the nozzle gun. Water is accordingly delivered at a high flow rate to the nozzle gun in the demand state, but recirculated at a much lower flow rate when the nozzle gun is in a demand state. The throttle control device also senses fluid pressure from the pump outlet to operate between engine starting and engine running modes. When hydraulic pressure is 0 or less than a predetermined threshold pressure, water is bypassed through a low-pressure hydraulic circuit to reduce the engine load during a manual start. After the engine has been started and the pump reaches the threshold pressure, the throttle control device operates to control the engine speed…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.