GB1052740A - - Google Patents

Abstract

1,052,740. Valves; screw and nut gearing. GROVE VALVE & REGULATOR CO. Sept. 1, 1965, No. 37401/65. Headings F2Q and F2V. In a valve actuator for rotating a plug, ball or butterfly valve closure through 90 degrees, the actuator mechanism is housed within a welded housing formed by a base-plate 11 and side plates 12 a-f on which a cover plate 14 is bolted and comprises a rotatable connector 18, surrounding and keyed to the valve stem 53, provided with a radially extending pair of parallel yoke arms 18b and 18c between which is slidably mounted, via force transmitting arms 26b, 26c, a slide member 26 which is slidable along a guide rod 44, mounted between housing side plates 12a, 12c (Fig. 1, not shown), by engagement with a screw 29 rotated by a wheel or crank and extending parallel to the guide rod 44 and also mounted, via bearings 31, in side plates 12a, 12c. Reciprocation of slide member 26 along screw 29 and guide rod 44 causes rotation of the connector 18 between limits determined by 'adjustable stops 48 (Fig. 1, not shown) which abut one of the yokes 18 and the valve position is indicated by a pointer 58, on the exterior of the housing, which is attached to the connector 18. The effect of forces transverse to the screw 29 and guide rod 44, which are developed during actuation, is minimized by a clearance between rod 44 and the hole 46, wherein it engages in the slide member 26, which permits bending of the rod 44 and by the formation of the thread between the screw 29 and member 26 with a root dimension R (Fig. 3, not shown), greater than the crown dimension C. The screw 29 may be rotated manually or electrically or, in an alternative embodiment (Fig. 4, not shown), by a pair of double-acting piston motors 61 mounted on the plates 12a, 12c and with the rods 76 attached to the slide 26 for reciprocation thereof in place of screw 29. Screws 38 secure the actuator driving assembly 37 from within the actuator housing to facilitate removal thereof without dismantling.