| 摘要 |
A needle valve (10) having improved accuracy and wear characteristics is disclosed in which the valve stem (40) is subjected to a constant force to prevent backlash throughout its entire movement with respect to the valve seat (26). In addition, the needle (64) contained within the valve stem (40) has a tapered end which moves within the cylindrical bore in the valve seat (26) to control fluid passing through the valve and such needle (64) is affixed to the valve stem (40) only at its other end remote from its tapered end (66). The needle (64) thus floats for a substantial portion of its length and its tapered end is relatively flexible and free of movement. The needle (64) is, however, angled with respect to its valve seat (26) such that the needle (64) physically makes contact with the internal surface of the valve seat (26) and maintains that contact throughout its lateral movement within the valve seat (26). |
