GB815971A - Improvements in or relating to a seal between a sliding rod or piston and cylinder - Google Patents

Abstract

815,971. Piston packings. REGIE NATIONALE DES USINES RENAULT. Nov. 22, 1955 [April 26, 1955; June 23, 1955], No. 33476/55. Class 122 (1). [Also in Group XXIX] A seal between a sliding rod or piston and a cylinder containing fluid under pressure comprises a packing ring having an annular body 16, Fig. 5, which is placed under tension in a groove 17 in the rod or piston so that it ensures fluid-tightness along several spaced surfaces of contact with the groove and is of such outer diameter that it forms a guide bearing between the rod or piston and cylinder, and a tapering lip 18 which is connected with the body by a portion 31 thinner than the adjacent part of the lip and applied under tension against the inner wall of the cylinder. Instead of being of circular cross-section as shown in Fig. 5, the annular body may be of substantially square or rectangular cross-section, in which case it may engage against ribs 32, 34, 33 formed on the bottom and one side face of the groove as shown in Fig. 6 and one of its end faces may be recessed to co-operate with the rib 34. The reduced neck portion between the annular body and lip is provided by forming a groove 31 on either the inner or outer face of the ring. In the construction shown in Fig. 3, the packing ring opposes the passage of fluid from the chamber 21 to the chamber 22 as the piston enters the chamber but peripheral grooves 24 in the ring permit it to act as a valve and allow fluid to pass from the chamber 22 to the chamber 21. Two packing rings of the kind shown in Fig. 3 may be arranged in opposed and spaced relation on a single piston (Fig. 4, not shown).