| 摘要 |
<p>The system employs jacks (18,28) acting on radius arms (15,25) to drive the rotatable spherical obturators (11) of a double valve fitting (10,20) for large water dia. pipes. The fitting may be used in the hydroelectric field, and combines two such drive mechanisms to obviate massive offset jack re-action blocks. Two obturators may be sited at relatively close centres on the pipe axis, each being mounted on stub axles (12,13,22,23) located by journal bearings incorporated in the housing walls. The axes about which the obturators rotate are parallel and the axles, pass through the housing wall to provide for the connections of the jacks and the radius arms. Diagonally opposed stub axles (22,12) may secure the fixed but rotatable ends of the respective jacks (28'18), and the jack remote ends of the arms (15,25) may be keyed to the two remaining stub axles (13,23).</p> |
