IMPROVEMENTS IN DUAL STAGE VALVE

摘要

1,261,059. Valves. GENERAL ELECTRIC CO. 5 Sept., 1969 [12 Sept., 1968], No. 44002/69. Heading F2V. In a valve through which fluid flow can take place at two different and basic flow rates, the valve outlet 11 is comprised of two members 14 and 18 which are in mutual screw-threaded engagement, in combination afford a single outlet port 22, and which have their other ends projecting into the interior of a flow chamber 4 having an inlet (8, Fig. 1, not shown). The projecting innermost ends of members 14 and 18 constitute seats for a compound closure member comprised of two relatively movable and concentric closure members 39 and 44 respectively, with a projection 40 on member 39 being attached, through a lost-motion spring coupling, to a compensating bi-metallic strip 35, the other end of which is coupled to a controlling bimetallic strip 33 having disposed there around an insulating sheet 51 and a heating coil 50. In operation, and in the absence of current in coil 50, closure members 39, 44 engage their respective seats with any fluctuations in ambient temperature being compensated for by strip 35, this latter bi-metallic strip flexing oppositely to the direction of flexing of strip portion 34 of bimetallic strip 33. Upon applying a current to coil 50, bi-metallic strip 33 flexes and so compresses spring 42 until closure member 39 is forced to detach from its seat, such detachment permitting a limited flow from chamber 4 and through port 23 to outlet 22. Further flexing of strip 33 results in a ledge 46 on member 39 engaging a projection 45 of the inner valve member 44 and hence raising it from its seat with the result that additional flow can then take place through the seat and on to port 22, the amount of additional flow being dependent upon the disposition of member 44 in relation to its seat and hence upon the degree of flexing of strip 33.