Tamper resistant adjustment valve for a charge forming device

Abstract

In at least some implementations, a valve for a charge forming device, includes a needle having a first end and a second end, and a valve body. The valve body has an axis extending between a first end and a second end, and a cavity open to the second end and in which part of the needle is received with the second end of the needle extending out of the second end of the valve body. The valve body also has a projection extending axially from the first end of the valve body to a free end of the projection, and the valve body has at least one drive surface axially spaced from the free end, the drive surface extends axially and radially.

1 . A valve for a charge forming device, comprising:
 a needle having a first end and a second end;   a valve body having an axis extending between a first end and a second end, a cavity open to the second end and in which part of the needle is received with the second end of the needle extending out of the second end of the valve body; and   a projection extending axially from the first end of the valve body, wherein the valve body has at least one void defining at least one drive surface radially spaced from the axis, the drive surface extends axially and radially.   
     
     
         2 . The valve of  claim 1  wherein the projection is defined by the needle and the first end of the needle defines a free end of the projection. 
     
     
         3 . The valve of  claim 1  wherein the projection is coaxial with the valve body. 
     
     
         4 . The valve of  claim 1  wherein the at least one drive surface includes at least two drive surfaces that are defined on opposite sides of the void. 
     
     
         5 . The valve of  claim 4  wherein the void is a slot formed in the first end of the valve body. 
     
     
         6 . The valve of  claim 5  wherein the slot intersects the cavity in which the needle is received. 
     
     
         7 . The valve of  claim 5  wherein the slide defines opposed drive surfaces that are spaced apart a distance greater than the diameter of the needle. 
     
     
         8 . The valve of  claim 4  wherein the void is formed in the first end of the valve body and the void extends axially into the valve body, and the void opens radially outwardly through a periphery of the valve body. 
     
     
         9 . The valve of  claim 8  wherein the void does not intersect the cavity in which the needle is received. 
     
     
         10 . The valve of  claim 1  wherein the cavity extends through the first end of the valve body. 
     
     
         11 . The valve of  claim 8  wherein the void is in the shape of a portion of a cylinder. 
     
     
         12 . The valve of  claim 1  wherein the void has an axially facing entrance adapted to receive part of a tool used to rotate the valve. 
     
     
         13 . The valve of  claim 1  wherein the valve body includes an exteriorly threaded portion and the void is formed in a non-threaded portion extending between the second end and the threaded portion. 
     
     
         14 . The valve of  claim 4  wherein the void is formed in the first end of the valve body and the void extends axially into the valve body, and the void does not open radially outwardly through a periphery of the valve body. 
     
     
         15 . A tool for rotating a valve that has a projection extending axially beyond a drive surface to be engaged by the tool, the tool comprising:
 a body including a shank having an axis, one or more driving surfaces and a cavity formed in the shank, the cavity extending axially into an end of the shank and adapted to receive at least part of the projection, and the one or more driving surfaces extending axially beyond the end of the shank and cavity, and the one or more driving surfaces being radially spaced from the cavity and arranged to engage a surface of a valve upon rotation of the tool.   
     
     
         16 . The tool of  claim 15  wherein the one or more driving surfaces is defined by a projection radially spaced from the cavity. 
     
     
         17 . The tool of  claim 15  wherein the axis intersects the cavity and the one or more driving surfaces are radially spaced from the axis. 
     
     
         18 . The tool of  claim 15  wherein the one or more driving surfaces are located radially outboard of an exterior surface of the shank. 
     
     
         19 . The tool of  claim 15  wherein the tool includes a working end at one end of the shank, and the working end is radially larger than the shank, and the cavity is formed in the working end of the tool. 
     
     
         20 . The tool of  claim 15  wherein the one or more driving surfaces are defined by two fingers that extend axially from the shank and are located on opposite sides of the cavity, a distance between the two fingers being equal to the diameter of the cavity.