(under subclass 48) Subject matter wherein a tool couple joins together the margins of a piece of work that has been deformed into a helical coil having adjacent side margins, whereby the product formed is a conduit or pipe having a helical joint.
(1) Note. Usually the helical coil is deflected by structure which, per se, is found in subclasses 135+ (which see) and an additional deformation is imposed on the work (either before, during, or after coiling) to change the cross-sectional shape thereof so that the adjacent margins will associate intimately to form a helical seam. The illustrations below (in the Figure accompanying this note) exemplify only a few of the various forms of seam disclosed in the art. [figure]
