Method for severing rings from a coil

Abstract

A helical coil comprising a plurality of turns of bar stock is mounted on an expanding mandrel which is operated by a hydraulic cylinder or the like to expand the internal circumference of the coil against the resilient resistance thereof. A severing device is then employed to form a cut across the turns of the coil so as to sever each turn as a separate ring having a gap therein corresponding in width to the thickness of the severing device. The expanding mandrel is then released so as to allow the rings to spring back to their original circumference. In this way, the gap in each ring is closed. Each ring may then be flattened to remove the helical pitch so that the ring will be in a single plane with the severed ends of the ring aligned. The severed ends may be welded or otherwise joined. The disclosed machine preferably employs a rotary abrasive disc for forming the cut across the turns of the coil. The width of the cut corresponds to the thickness of the abrasive disc. The amount by which the coil is expanded preferably corresponds to the thickness of the abrasive disc so as to compensate for the width of the cut produced by the abrasive disc. The continuing abrasive action of the sides of the disc, as the cut progresses across the turns of the coil, prevents the disc from being pinched by the turns of the coil.

Dependencies are inferred from the claim text.