Abstract: For fabricating a compression piston ring, two identical split-ring members are formed, each having parallel planar side faces and a cylindrical outer edge face. For each ring member, circumferentially overlapping fingers are formed at the adjoining ends, one being an outer finger and one being an inner finger; and these fingers are provided with radially contiguous cylindrical faces, concentric with the outer edge face. The confronting side faces of the two ring members are preferably provided with a lap finish. The rings are assembled in side-by-side contiguous relation, with the outer finger ends thereof overlapping to some extent; and these overlapping ends are joined by means of at least one silver solder joint which is located adjacent to the outer fingers, so that these outer fingers are protected by the adjacent ring member.

Abstract: A ring assembly includes two side-by-side flat ring members of uniform rectangular cross-section each being split, with the confronting split ends having radially overlapping fingers to define a circumferentially sealing joint. The ring members are dimensioned to be received in a common piston groove with the ring members being non-rotatably coupled so that the joint of one member will always be rotationally spaced from the joint of the other to define an axial seal for the ring assembly. A non-rotational coupling is provided by an integral tab formed in one member and projecting transversely therefrom and received in a mating transverse recess in the other member, with the recess having a larger dimension than the tab to permit sliding movement of the ring members relative to each other within the groove. Two forms of tabs include a partially sheared and bent tab and a partially displaced shear plug.

Abstract: A unitary spiral ring structure is fabricated from side-by-side split ring members with one end of one ring joined in overlapping relation to one end of the other ring by means of a silver soldered or other fused metal joint. The mating ends of each ring member are interlocking with the free ends being radially confined by the respective joined ends. An auxiliary expansion ring improves the sealing of the spiral ring.