GB864659A - Improvements in solenoid-operated fluid-flow control valves - Google Patents

Abstract

864,659. Valves. HOSKINS, S. W. July 10, 1957, No. 21903/57. Class 135. Between the walls 3A, Fig. 1, of a valve casing 2 and an inner-tube assembly 3 is disposed a solenoid coil, not shown, whilst coaxially disposed in the assembly is a brass inlet 1 and a soft-iron outlet 9, the inlet 1 having a skirt 11 to the lower end of which is threaded a soft-iron polepiece 14 that co-operates with an armature 13 capable of a small axial movement in a chamber 12 in the skirt 11; the armature has a pilot valve 17 adjustably mounted therein, the valve 17 embodying a conical tip 17A with opposed flats which coacts with a pad 16 of elastically deformable plastic material to control a passage 26 through the polepiece. Slidable over polepiece 14 and skirt 11 is a brass main-valve closure 8 that co-operates with a seat 10 on the outlet 9. With the solenoid de-energized a spring 28 in a chamber 21 of the closure 8 urges the latter on to its seat 10 so fluid entering the inlet 1 passes through an annular space 7 between the assembly 3 and the closure 8 and enters chamber 21 via an orifice 22 from whence it flows by axial passages 20 to the chamber 12 between the polepiece and armature, and since a spring 13A unseats the valve 17 the fluid in chamber 12 escapes through passage 26 to the outlet 9. A pressure difference is in consequence created between the opposing faces of the closure 8 and the latter opens when the inlet pressure in the space 7 below the closure attains a given value. Upon energizing the solenoid the armature 13 is attracted to the polepiece 14 and seats the valve 17 thereby closing passage 26 whereby the difference between the static pressure in the chamber 21 and the dynamic pressure acting beneath the closure 8 in the space 7 seats the closure 8 with the aid of the spring 28. In a modification, the main valve seat 75, Fig. 2, is formed at the inlet, the valve 76 cooperating therewith and being guided in the inner tube assembly 74 by fins 78; slidable in the valve 76 is the armature 81 that has the pilot valve 86 secured therein, which armature coacts with the polepiece 92A that is part of the outlet 92. The pilot valve 86, which controls flow through passages 84, 88, 101 and chambers 79A and 89, has its seat 100 in the polepiece 92A. The main flow to the outlet 96 takes place through the annular space 83. Specification 864,454 is referred to.