| 摘要 |
<p>1460200 Linkwork; interconverting rotary and reciprocating motion; conveying rotary motion; valves GENERAL SIGNAL CORP 18 June 1974 [3 Aug 1973] 27018/74 Headings F2K F2Q and F2V In a Scotch yoke mechanism for a valve actuator in which a butterfly-valve shaft 26 is turned by a slotted crank arm 110 moved by a slipper block nut 130 on a rotatable, or axially reciprocable (Figs. 6 and 7, not shown), leadscrew rod 64 in a housing 62, the nut 130 has oppositely extending transverse projections 132, 134 supported by slipper members 98, 75 slidable on tracks 100, 74, in the housing 62, to absorb sideward thrust to minimize bowing and twisting in the yoke crank arm 110 and rod 64. Adjustable stop nuts 90 on the rod 64 limit overall axial movement of the rod 64 corresponding to the fully open and shut valve positions, a visual marking 102 on the nut slipper member 98 readily indicating such positions through a housing window 104.</p> |
