Ring manufacture, productive of line contact seal

Claim 1

Apparatus for lapping, on a confronting surface, an interposed split ring which is to be localizedly side lapped at only an inner periphery thereof adapted to project into contact with said confronting surface, the ring being one which, when in a collapsed state conforming to a cylinder bore size for which nominally designed, becomes closed or substantially so at the split in the ring, said ring having a relaxed state in which the split opens up to impart to the ring its larger, free-spring diameter, said apparatus comprising: a ring fixture having an open mouth for receiving the ring, said mouth being cylinder-bore-shaped of a smaller diameter than the free-spring diameter of the ring; a lapping surface confronting said mouth in spaced apart relation to the ring fixture; said mouth being of a size and shape equivalent to said cylinder bore to insure retention of the received ring precisely in collapsed state at all times, for holding the ring relative to the lapping surface so that said ring side forms at all times a slight angle to said surface whereby to provide the ring side with a lapped narrow sealing band at said locally contacting inner periphery; the cylinder bore-shaped open mouth of the ring fixture characterized by a ring-engaging bottom therein deep enough so that, when the ring is bottomed in the mouth, the mouth can engage and hold the ring by the latter''s outer periphery in a properly radially collapsed state, and shallow enough therein that the projecting inner periphery of the ring will constitute freely and solely the protruding structure establishing the requiring lapping contact; and means fOr causing relative movement between the fixture and confronting lapping surface in at least one direction of lap the confronting lapping surface being convex-spherical.