| 摘要 |
<p>An arrangement for converting rotary motion of a cam (9) on a camshaft (1) into periodic linear movement of a poppet valve (8) guided for linear movement by a guide (7). The valve has a bucket (5) acted upon by a valve spring (not shown) and provided with a tapered shoe (4) presenting a curved contact surface. A cam follower (3) is pivotally mounted on a pivot (2) defining a pivot axis parallel to the axis of rotation of the camshaft (11). The follower (3) is resiliently biased (CS) into contact with the cam (9) and shoe (4). The pivot (2) is angularly adjustable about a datum axis (D) parallel to the axis of rotation of the camshaft, so that the linear displacement of the valve (8) is variable in dependence upon the selected angular position of the pivot (2). In another arrangement embodying the invention the camshaft passes through a ring-shaped follower pivotally on an angularly adjustable pivot and the camshaft co-operates with an internal surface of the follower to effect displacement of the valve.</p> |
