GB721265A - Improvement in or relating to motor operated valves - Google Patents

Abstract

721,265. Controlling change-speed gear; friction clutches. PHILADELPHIA GEAR WORKS, Inc. Dec. 15, 1952. No. 31758/52. Class 80 (2). [Also in Groups XXIX and XXXVII] A valve unit having a valve 14, Fig. 1 and stem 15, 32, 33, operated by power drive means, e.g. the switch controlled electric motor 28, has a two-speed gear mechanism 23 in the drive means comprising a primary shaft 54, Fig. 4 a primary input pinion 60, fixed on the input end and a larger primary gear 61 rotatable on the output end of this shaft, a first clutch 62 on the primary shaft for connecting the larger gear to the shaft, a countershaft 57, a larger secondary gear 69 rotatable on this shaft and meshing with the primary input pinion, a secondary pinion 68 fixed on the output end of the countershaft and meshing with the larger primary gear, a second clutch 70 on the countershaft for connecting the larger secondary gear to the shaft, interconnecting means 78-80' for engaging one clutch while disengaging the other, power means, e.g. the solenoids S', S', moving armature A', A<SP>2</SP>, connected to an arm L for operating the interconnecting means, and control transmitting means, e.g. the electrical contacts 34, T', T', T' 'governed by the travel of the valve stem, for controlling the power means whereby the interconnecting means are maintained in highspeed position during the first portion of the valve closing movement and in low-speed position for the remainder of the closing movement. The casing 17 contains limit switches stopping the motor when the valve is fully open or closed. The valve may also be actuated manually by wheel 18. The high speed solenoid S' clutches the gear 69 to the countershaft while the low speed solenoid S' clutches the gear 61 to the primary shaft. The low speed solenoid S' may be replaced by a spring for clutching the gear 61, in which case the contact rail T<SP>3</SP> is unnecessary. For a rotary valve the contact 35 rotates over circular rails T<SP>2</SP>, T<SP>3</SP>. The clutch operating power means may be controlled by a clockwork or timing device. Each clutch comprises a collar 63 or 71 respectively rotating with the shaft 54 or 57 and shiftable by the fork 72 or 74 towards the gear 61 or 69 to depress a set of cam rollers on rockers which bear on a cam ring to compress clutch leaves.