| 摘要 |
<p>Axial displacement between two components (10, 17) of a valve occurs as a result of relative rotation through the cooperation of helical ramps (29, 31). Preferably another pair of helical ramps (30, 38) is provided concentric with the first but angularly offset 180 DEG with the result that when the components (10, 17) are at maximum axial separation the residual contact between the ramps of each pair (shaded areas in Fig. 5e) will be on oposite sides of the axis x of rotation and prolongation, thus preventing tilting of the component (17) out of axial alignment with the component (10). In other constructions more than two pairs of ramps are employed. In the embodiment illustrated the ramp means of the invention replaces a screw-thread to provide adjustment of the loading of a valve spring and permits the use of more economical manufacturing and assembly techniques.</p> |
