| 摘要 |
1,201,872. Linkwork. FORD MOTOR CO. Ltd. 10 July, 1968 [13 July, 1967], No. 32884/68. Heading F2K. [Also in Division F1] A mechanism for converting rotational motion of a cam 14a into reciprocating motion of a reciprocating member, e.g. an I.C. engine inlet or exhaust valve 8, through a rocker arm 17 includes a fulcrum lever 18 positioned by an eccentric 28. Changes in the angular position of the lever 18 as determined by the eccentric 28 vary the timing of valve operation and also valve lift. During valve operation the point of contact 19 between the lever and rocker arm surfaces 22 and 24 moves to the left from a position on the line of intersection 23 of the lever pivot axis and the valve stem axis with the valve closed. The surfaces 22 and 24 are contoured to provide the desired valve operating characteristics. The eccentric shaft 26 may be rotated manually or by a servomotor responsive to engine speed or manifold vacuum. The valve (8<SP>1</SP>), Fig. 5 (not shown), may be actuated by an overhead cam-shaft (14<SP>1</SP>) contacting the rocker (17<SP>1</SP>) directly. The valve (8<SP>11</SP>), Fig. 6 (not shown), in a cylinder block (9<SP>1</SP>) may be actuated by the rocker arm (17<SP>11</SP>) through a tappet (15<SP>1</SP>). An hydraulic clearance adjusting device may provide the pivot for the lever 18. |
