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US 10,738,741 B2Granted
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.
Claims15
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, wherein the first needle valve has a plurality of serrations which define the at least one drive feature of the first needle valve and the first limiter cap has a plurality of serrations which define the at least one drive feature of the first limiter cap, and wherein at least one serration on the first limiter cap is not aligned with a space between two adjacent serrations on the first needle valve when the first limiter cap is advanced axially onto the first needle valve from the first position to the second position and the at least one serration on the first limiter cap is deformed upon installation of the first limiter cap on the first needle valve.
1 more element
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, wherein the at least one tamper resistant feature includes one or more flexible fingers that define a cavity, the flexible fingers being defined in part by voids between adjacent flexible fingers with the voids extending through the first limiter cap, and wherein the voids permit the flexible fingers to move relative to each other so that the volume of the cavity decreases when the first limiter cap is advanced axially onto the first needle valve from the first position to the second position inhibiting access to the first needle valve.
1 more element
Dependencies are inferred from the claim text.