Carburetor arrangement for changing the ratio of the air/fuel mixture in handheld motor-driven apparatus
US4787356A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 26, 1987 |
| Grant date | Nov 29, 1988 |
| Priority date | — |
| Expiry date | Jun 26, 2007 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S261/68
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A carburetor arrangement changes the ratio of air and fuel in the air/fuel mixture for an internal combustion engine of a handheld motor-driven apparatus such as a chain saw, hedge trimmer or the like. The carburetor arrangement includes a membrane carburetor with a regulating membrane by means of which a valve needle is lifted from a valve seat against the force of a spring. The valve needle and valve seat conjointly define a valve for admitting fuel into a chamber of the carburetor. A positioning member is mounted with respect to the regulating membrane and is actuable in dependence upon the rotational speed of the engine. The actuation occurs such that the valve needle is additionally displaced a further incremental amount in response to a predetermined rotational speed of the engine thereby enriching the air/fuel mixture by an additional amount.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.