| 摘要 |
1405606 Making poppet valves SOC D'ETUDES DE MACHINES THERMIQUES 7 Dec 1972 [10 Feb 1972] 56455/72 Heading B3A [Also in Divisions F1 and F2] A method of manufacturing a liquid cooled poppet valve (see Divisions F1 and F2) having a stem 1 and a screwed in valve head 4, comprises drilling two separate spaced-apart ducts in the stem, or extruding the two ducts, and thereafter twisting the stem to cuase the ducts to extend helically about the longitudinal axis of the stem. |
