Vacuum operated valve arrangement
US4193383A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 27, 1978 |
| Grant date | Mar 18, 1980 |
| Priority date | — |
| Expiry date | Jul 27, 1998 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02M25/0854
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
In an evaporative control system for reducing emission of fuel vapors from an engine fuel system there is provided a vacuum operated valve arrangement having a two-position valve which is spring biased to open to permit venting of fuel vapor from a carburetor fuel bowl to a carbon canister when the engine is not running and is responsive to engine vacuum only above a predetermined negative pressure to close to prevent such venting when the engine is running, and a check valve and bleed valve arrangement which is operable to trap engine vacuum at the two-position valve at a vacuum at or above the predetermined negative pressure whenever the engine vacuum drops below such pressure to thereby maintain the two-position valve in its closed position preventing fuel vapor venting during engine running at low engine vacuum and operating to release the trapped engine vacuum at the two-position valve to thereby permit the valve to open to permit fuel vapor venting when the engine is not running.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.