Charge forming device with adjustable valve limiter
AssigneeWalbro Corporation
InventorsYoshiaki Doyama, Teruhiko Tobinai
Life of this patent
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Abstract
A charge forming device may have a rotatable fuel adjustment valve received in a passage of a body of the device. A limiter cap may have a driving feature engageable with a drive feature on the valve and having a first position permitting rotation of the valve relative to the limiter cap and a second position permitting only lesser rotation of the valve than that of the first portion. The limiter cap may have a tamper restraint feature that retains the lesser range of rotation.
Claims16
A carburetor, comprising:
- a body having a fuel passage formed therein, and a first needle valve passage communicating with the fuel passage;
- a first needle valve received in the first needle valve passage for rotation about an axis, having a tip movable relative to a portion of the fuel passage to control the flow rate of fuel in the passage, a head having one or more drive features formed thereon, and a tool engaging feature by which the needle valve may be rotated;
- and
- a first limiter cap installed on the first needle valve, having at least one driving feature engageable with at least one drive feature on the first needle valve, having a first position permitting rotation of the first needle valve relative to the first limiter cap and a second position permitting a lesser range of rotation of the first needle valve than the first position, the first limiter cap having at least one tamper resistant feature that retains the lesser range of rotation after tampering.
The carburetor of claim 12 wherein the first and second limiter caps each have an anti-rotation surface which are adjacent to one another when the first and second limiter caps are inserted into their respective first positions.
A method of providing a carburetor to a second manufacturer, comprising the steps of:
- inserting a first needle valve in a carburetor body at a first manufacturer;
- inserting a first limiter cap to a first position on the first needle valve at the first manufacturer;
- and
- providing the carburetor assembly to a second manufacturer for the second manufacturer to calibrate the needle valve to adjust fuel flow in the carburetor and then move the first limiter cap to a second position on the first needle valve that restricts the adjustability of the first needle valve.
A limiter cap assembly for a carburetor having a cavity in which one or more adjustable valves are received, the assembly comprising:
- a plug adapted to be received within a cavity of the carburetor and having an opening and a cavity aligned with the opening;
- a clasp engageable with the plug and having at least one retention feature and an opening aligned with the opening of the plug;
- and
- a limiter cap received within the opening of the plug and engaged with the retention feature of the clasp so that removal of the limiter cap from the plug opening is prevented by engagement of the retention feature with the limiter cap and by engagement of the clasp with the plug.
Dependencies are inferred from the claim text.