GB878816A - Power driven actuating mechanism for fluid control valves - Google Patents

Abstract

878,816. Valves. PHILADELPHIA GEAR CORPORATION. June 18, 1959 [Feb. 6, 1959; April 24, 1959], No. 20942/59. Class 135. A valve has a threaded stem P rising from the valve gate through a drive mechanism comprising a first housing 19 containing a rotatable drive nut 30 threaded on the stem and having limited axial movement therewith, a drive sleeve 12 axially supported by bearings 26, 27 around the nut for transmitting rotation from a power source to the nut, e.g. via worm 29 and pinion 11 on the sleeve, and splines between the sleeve and nut, a second housing 37 on the first having a top inward flange 40 forming a guide opening F and downward face 41, a non-rotatable axially movable thrust member having a bell part 47 with an upward face 50 and a neck part 49 passing through the opening F<SP>1</SP> and into which the stem enters, a spring around the neck and confined between the faces 50, 53, means for transmitting thrust upward from the nut to the thrust member and spring due to reaction when the valve closes or downward from spring to thrust member and nut due to reaction when the valve is fully opened, including an annular adapter 34 coupled to and extending up from the nut for axial and rotary movement therewith, thrust bearings 55-56 coupled between the adapter and bell part for axial movement therewith, and additional upper face means 53 coupled and movable with the neck and additional lower stationary face means 46 between which the spring is also confined. The spring is compressed between faces 50 and 41 as the nut moves up when the valve seats and between faces 53 and 46 as the nut moves down when the valve reaches its open position to prevent excessive pressure on the valve gate. An indicator 66 determines the thrust in the valve stem and a lubricant passage is formed at 60, 62, 65. U.S.A. Specification 2,878,687 is referred to.