GB696545A - Improvements in flexible diaphragms - Google Patents

Abstract

696,545. Valve closure members. SAUNDERS VALVE CO., Ltd. Jan. 24, 1951 [Feb. 3, 1950; June 29, 1950], Nos. 2878/50 and 16278/50. Class 135 A flexible diaphragm of rubber &c. and suitable for use in a diaphragm valve has a facing of a material more inert chemically than natural or synthetic rubber &c. and formed with an integral projection or projections by which it is mechanically interlocked with the diaphragm. The facing may be of a polymerized halogen-substituted ethylene such as polymerized tetra-fluoroethylene. In Fig. 1 the facing 4 has integral lugs 5 which receive metal pins 6, whilst in another arrangement laces integral with the facing are knotted together after passing through holes in the diaphragm. Fig. 4 illustrates a method of attachment consisting in clamping under a metal cap 10 the ends of lugs 9 which are apertured for the passage of a stud 3 moulded into the diaphragm. The stud serves for the attachment of actuating means for the diaphragm as in Specification 434,665. As shown in Fig. 6, the facing has laces 11 or lugs 12 which are passed through a lower layer 1a and a reinforcement of the diaphragm and are then tied or bent over after which an upper layer 1b is applied and the whole subsequently cured. Fig. 7 illustrates the use of dovetail or T-section lugs which are embedded in the diaphragm before it is cured. Alternatively, the facing may have an upstanding cylindrical lug which is embedded in a central boss of the diaphragm before curing. In this case, holes are formed in the lug and become filled by the material of the diaphragm during curing. Another method consists in embedding in a central boss on the diaphragm a boss integral with the facing and then curing. A stud is embedded in the boss of the facing. Fig. 12 illustrates the use of a facing consisting initially of two parallel discs interconnected by an integral boss 19 of small diameter and cut from solid bar. One of the discs, 4, serves as the facing proper whilst the other is cut to form radial fingers, alternate ones, 23, of which have holes which are passed over a stud 3 whilst the others, 22, extend radially within the material of the diaphragm. A rubberized fabric reinforcing piece 26a passed over the stud has radial arms 26b which pass through holes 24 in the fingers 22. Other holes 24 are formed in the fingers 22 and 23 into which the material of the diaphragm flows during curing. Specifications 585,607; 657,324 and 685,935 also are referred to.