GB855123A - Improvements in or relating to fluid flow control means - Google Patents

Abstract

855,123. Regulating fluid flow; valves. MANNING, MAXWELL & MOORE Inc. June 11, 1957, No. 18393/57. Class 135. A flow restrictor device comprises two relatively movable elements defining a chamber having at least one inlet and outlet between which is located a dam or barrier member which co-operates with a groove in one of the elements to define a restriction, the groove being of varying cross-section so that relative movement of the two elements varies the size of the restriction. In the first example, Fig. 15, a block 402 rests on a rigid base 400. A chamber 404 has an inlet 412 which communicates with an outlet 411a via a restriction 409a and the bore 410a of a ring member 413. The restriction 409a is formed by the top of the barrier member 413 and a longitudinal groove 406 in the member 402. A resilient 0-ring 414 urges the ring member 413 upwardly. The groove 406 may be of constant or varying width and depth with the base straight or curved to give a desired linear or non-linear response. In another example, Fig. 1, the rigid base 50 and the block 52 are of circular form, the block being rotatably mounted on the base by a shoulder screw S. Circular 0-rings 53, 54 define an annular chamber 55 having an inlet 56 and an outlet 57. The dam or barrier 60, Fig. 3, has a central core and is urged upwardly by a resilient 0-ring 59 to co-operate with a spiral groove 62 of increasing size on the underside of the knob or block 52 rotation of which varies the restriction formed by the groove and the dam member 60. The groove 62 ends in a rectangular recess so that maximum unrestricted flow may be obtained. A casing 64 containing a bellows 65a is secured to the base 50. The inlet 56 communicates with the interior of the casing and the outlet 57 with the bellows 65a. There may be provided two chambers 55, two spiral grooves, two inlets and two outlets and two barrier members. If the groove is of spiral form, Fig. 10, the barrier member 96 is guided by a rib 99. In a modification the groove of varying size is formed on a cylindrical plug 72a, Fig. 9, rotatable within a cylinder 70a. In another example, Fig. 4, the base 50a has three ports 56a, 56b, 57 communicating with the chamber 55. The ports 56a, 56b communicate with the chamber 55 through the central bore of barrier members 60a 60b which co-operate with separate oppositely tapering spiral grooves. If the ports 56a, 56b are used as inlets for fluids of different pressures the outlet pressure will vary in accordance with some of the restriction areas. In a modification of this embodiment the grooves are formed on a cylindrical plug member.