GB888379A - Diaphragm pumps and motors - Google Patents

Abstract

888,379. Diaphragm pistons; engine valve gear. NATIONAL RESEARCH DEVELOPMENT CORPORATION. June 17, 1960 [May 7, 1959; June 18, 1959; Sept. 30, 1959; Jan. 25, 1960], Nos. 15669/59, 20955/59, 33148/59 and 2558/60. Classes 122 (1) and 122 (2). [Also in Groups XXVIII and XXIX] The diaphragm 1, Fig. 1a, of a vapouroperated diaphram motor is shaped at least in part in the form of two isosceles triangles having a common base or having their bases separated by a rectangle, Fig. lb, of flexible impervious material, e.g. rubber, and the figure so formed has its edges clamped by frames 2 and is bisected longitudinally by rigid spine members 3, 12, 13 connected to the diaphram material articulated to each other at adjacent ends 17, 18, 19 to allow of relative longitudinal movement and pivoted at 15, 16 to the frames 2; the triangular portions of the diaphragm being rendered transversely inextensible, e.g. by securing textile strips across the rubber sheeting; the rectangular portion being rendered inextensible in both the transverse and longitudinal directions and a surplus of rubber sheeting being provided within the boundary of the frames 2 to allow movement of the diaphragm out of the plane containing the clamped edges. The splines are secured to the rubber sheeting by a rubber rib 4, Fig. 2e, associated with a rubber tube 5 on either side thereof and which serves to press the diaphragm in its extreme position against the lowermost part of the motor chamber wall 6. Control of supply and exhaust of vapour to and from chambers A, B, Fig. 6, into which the motor casing is divided by the diaphragm 1 is effected by valves 37 . . . 40, Fig. 7, mounted on a common stem 51 which is positioned by a cam 52 engaging a groove 53 in a valve stem control device 36. As shown, valves 37, 39 are open, whereby vapour admitted at 32 traverses a duct 34 leading to chamber B and chamber A is exhausted past valve 39 into a duct 50. At the end of the stroke the valve stem is moved so as to close valves 37 39 and open valves 38, 40, resulting in a return stroke. For maximum efficiency, vapour is cut-off from the working chamber before the end of each stroke by closing a normally open solenoid valve 33 in the supply duct 32. To this end coil 45 of valve 33 is in series with a coil 47 into which passes a magnetic rod 48 carried by the reciprocating rod 11.