GB519441A - Improvements in or relating to packing devices for pistons and the like - Google Patents

Abstract

519,441. Piston packing. AUTOMOTIVE PRODUCTS CO., Ltd., and CLENCH, E. C. S. Sept. 22, 1938, Nos. 27696/38 and 12416/39. [Class 122 (i)] A piston or like packing comprising a packing ring composed of a plurality of thin frustoconical rings 17, of metal or vulcanized fibre, capable of sliding upon one another and extending from the inside to the outside curved surfaces of the packing ring is constructed' so that the rings are supported by a frustoconical abutment 20, which preferably has a cone angle greater than that of the rings so that the rings can readily be pressed against the sliding surface of the piston or cylinder by fluid pressure. The rings are formed as superimposed separate rings, or of a helix of thin strip material with frusto-conical turns, and washers may be arranged between the rings. In Fig. 1 the rings are held to a piston 11 by means of a screwed sleeve 16 the lower edge of which is chamfered to suit the obliquity of the layers 18 of a wound helix or phosphor bronze, or tempered steel. In Fig. 2 the packing ring 17 is formed of number of washers of sheet vulcanized fibre formed with a central plane portion 27 and outer frusto conical parts 28 which are pressed into contact with the cylinder by a spring-pressed collar 34. The washers 28 are clamped between collars 25, 26 the collar 25 being formed with an abutment 20. In a modification of the device shown in Fig. 2 the ring 17 is arranged to act inwardly against a sliding plunger rod, and in a further modification, Fig. 5,-the rings 17 are shaped to provide a seal at both their inside and outside curved surfaces with a piston rod 9 and a cylinder 10. The piston head 11 is formed with an annular groove 45 somewhat U-shaped in cross-section and a clamping-member 47 of similar shape is operated by a nut 13 to hold the rings in place.