GB895787A - A device for sealing the joints of split piston rings and similar packing elements - Google Patents

Abstract

895,787. Piston-rings. LE MOUILLOUR, J. March 25, 1959 [March 26, 1958], No. 10367/59. Class 122 (1). A device for sealing the joints of split or segmental piston rings 1 comprises a coverplate 9 which is arranged underneath the ring in a groove 2 formed in the piston 3, and has a part 9c bent elastically into the joint. As shown in Fig. 1, applied to a piston ring 1 having a single lap joint formed by tongues 5, 6, the cover-plate 9, of resilient metal, is provided with an end portion 9b which, when the ring is assembled in the groove, is pressed into contact with the inner surface of the ring to seal the gap 8 in the joint. A lug 9c also formed on the end portion is bent, on assembly, so as to enter the gap 7 and, by its resilience, seal the latter gap. The end 9d of the plate 9 is so formed as to press the portions 9b, 9c into firm sealing contact, this contact being additionally increased by a leaf-spring 11 lapping over the portions 9b, 9c. Both the plate 9 and spring 11 are located in the ring 1 by the engagement of lugs 9a, 11a with corresponding grooves 10, 12. In the embodiment shown in Fig. 3, the pistonring is split into four identical segments 13, 13, 14, 14 having lap joints forming gaps 15, 16. The gaps 15 are sealed by end lugs 17c formed on a pair of cover-plates 17, the gaps 16 being sealed by end portions 17b formed thereon; the sealing portions 17b, 17c are pressed into sealing contact by a spring 19 and additionally by springs 20 overlapping the end portions. The internal diameter of the segments 13 is greater than that of the segments 14 in order to facilitate the entry of the lugs 17c. In modifications, the width of the cover-plates is made to equal half that of the segments and the coverplates are formed with end lugs for engagement with top and bottom gaps in the lap joints, the pairs of diametrically-opposed segments being recessed on opposite sides to receive the plates; leaf-springs are provided to ensure the sealing engagement of the lugs. In further embodiments, the width of one pair of diametrically-opposed cover-plates is equal to half that of the segments and that of the other pair the full width, the former pair of segments being recessed accordingly (Fig. 8, not shown). In the embodiment shown in Fig. 11, the four segments 41, 43 are connected by mortice-andtenon type joints and the sealing end portions 45c of the cover-plates 45 are shaped accordingly to seal the joint gaps 47; these portions are pressed into sealing contact by springs 51, 52. In a modification of the latter construction, one diametrically-opposed pair of segments is of reduced internal diameter to receive its pair of cover-plates. In further constructions, the joints are formed by interengaging triangular or rectangular shaped tongues and the sealing end portions of the cover-plates are arranged to fit into slots formed in the joints.