Tamper resistant carburetor needle valve adjustment limiter
US5707561A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 18, 1996 |
| Grant date | Jan 13, 1998 |
| Priority date | — |
| Expiry date | Jul 18, 2016 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/7062
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A limiter of the extent of adjustment of a fuel metering needle valve of a carburetor for an internal combustion engine. The limiter has a housing with a passage in which the head end of the needle valve is received and a cap received in the passage on the head end of the valve for rotation in unison with the valve. An arm carried by the body of the cap is engagable with a stop in the passage to limit to less than one complete revolution the extent to which the cap and needle valve can be rotated by an end user to adjust the needle valve. To provide a tamper-resistant limiter, the head of the cap is received in a bore of the housing passage with either only a slight clearance between them or an interference fit which also inhibits rotation of the valve by vibration of the operating engine on which the carburetor and limiter are utilized. Preferably, a non-circular recess in the head of the cap is constructed to receive the blade of a tool, such as a screw driver, to facilitate manually rotating the cap and the needle valve in unison within the limits provided by the arm and stop to permit only limited adjustment of the needle valve by an end user.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.