Abstract: Disclosed herein is a compound joint in which a lower section and an upper section are mated along a common contact plane. Means for positively interlocking the sections are provided in each section. A depressed area on the surface of each of the sections is oriented along the common contact plane, such that when the sections are interlocked, the depressed areas form an enclosed tube. A spreader tube comprising a metal that undergoes cold work hardening during expansion can be positioned within the enclosed tube, whereby the expansion of the spreader tube within the enclosed tube to a volume larger than the volume of the enclosed tube causes said interlocked sections to be permanently jointed.

Abstract: Disclosed herein is a compound joint in which a lower section and an upper section are mated along a common contact plane. Means for positively interlocking the sections are provided in each section. A depressed area on the surface of each of the sections is oriented along the common contact plane, such that when the sections are interlocked, the depressed areas form an enclosed tube. A spreader tube can be positioned within the enclosed tube, whereby the expansion of the spreader tube within the enclosed tube to a volume larger than the volume of the enclosed tube causes said interlocked sections to be permanently joined.

Abstract: A method and apparatus for producing a pipe connection are disclosed. The apparatus includes an inner pipe formed on the pipe to be joined which has a widened end part. An outer pipe in the pipe connector is dimensioned to receive the inner pipe and has an undercut formed therein to receive the widened end part. A sleeve is mounted inside the inner pipe with a close tolerance so as to be substantially free from play. The sleeve has a widened wedge-shaped portion which engages the inner pipe internally. As a result, the inner pipe is retained between the undercuts and the wedge-shaped portion of the sleeve.

Abstract: A method and apparatus for producing a pipe connection are disclosed. The apparatus includes an inner pipe formed on the pipe to be joined which has a widened end part. An outer pipe in the pipe connector is dimensioned to receive the inner pipe and has an undercut formed therein to receive the widened end part. A sleeve is mounted inside the inner pipe with a close tolerance so as to be substantially free from play. The sleeve has a widened wedge-shaped portion which engages the inner pipe internally. As a result, the inner pipe is retained between the undercuts and the wedge-shaped portion of the sleeve.