GB781125A - Piston sealing device - Google Patents

Abstract

781,125. Piston packing. GOETZEWERKE F. GOETZE AKT.-GES. July 21, 1955 [July 30, 1954], No. 21165/55. Class 122 (1). In a piston-packing arrangement comprising a resilient support ring 6 engaged in a peripheral groove 4a in the piston 4 and surrounded by a sealing ring 5 urged outwardly into contact with the cylinder wall by both the support ring and the pressure of the sealed gas acting on its inner surface, the sealing ring has a radial thickness less than that of the support ring and extends axially beyond the support ring. Circumferential grooves on the sealing ring 5 are engaged by corresponding ribs on the support ring 6 and gas leakage past the support ring is prevented by a packing ring 7. In a modification, Fig. 1 (not shown), the sealing ring is of L-section and its radial arm is supported in a groove in the support ring. In another modification, Fig. 3, the sealing ring 8 has three grooves in its inner surface engaged by the support rings 9 and tapers towards its free end. In a further modification, Fig. 6, the sealing ring 21 is engaged by two support rings 22, 23 housed in separate grooves in the piston, the groove nearer the gas pressure space being constructed so that gas can pass around the ring 22 to the inner surface of the sealing ring and the other support ring 23 being sealed in its groove by thin steel packing discs 13. The sealing ring may be coated with chromium on its sliding surface. The support ring and, preferably, also the sealing ring, are split rings.