Patent GB-1157873-A (GB)
Title: Improvements in or relating to Method and Apparatus for Joining Tubular Metal Elements
Inventor: SILVERMAN DANIEL
IPC: B21D39/04
Filed: 1966-07-19
Abstract: 1,157,873. Jointing by tube expanding; stamping. D. SILVERMAN, and H. M. LANG. 19 July, 1966, No. 32473/66. Headings B3J and B3Q. [Also in Division F2] A method of joining concentric, overlapping metal tube-ends 10, 11, Fig. 1, e.g. of round, square, triangular or oval cross-section, comprises encircling the ends with a restraining anvil or ring 16 and detonating an explosive 17 in the inner tube, a substantially incompressible transmission medium 19 being used to transmit the explosive force. A circumferential or segmental ridge or depression 15 is provided in the ring 16, against which the ends are forced by medium 19 (e.g. a jell, rubber, plastics, grease, wax. or a liquid or jell in a plastics capsule) which supports the explosive 17. After the joining operation, the ring 16 is removed. Two pipe ends may be joined to opposite ends of a collar in separate operations or simultaneously, Fig. 5. The hinged, external die 45 has at least one recess 46 at each end. In another form, Fig. 3 (not shown), at least two depressions are formed in the die (27), and at least one carrier (30, 30a) is used for the explosive. The ring 92, Fig. 9, may remain on the joint, and rings of other forms (Figs. 10-13) may be used. In another form, Fig. 4, a stop-flange 74 is formed within the collar 62, and the explosive assembly is contained in a plastics capsule 78. Compressible material 70-72, such as paper, compressed or cemented saw-dust or plastic foam, may be used on each side of the charges 66, 67. A locating recess (74c, Fig. 7) for the capsule may be formed in the flange (74a) so that the collar and capsule can be transported as a unit. A layer of incompressible, deformable material 110, Fig. 8, e.g. rubber or a plastics, may be placed between the tube-ends 100, 101. If a swivel joint is required an intermediate layer of wax or grease may be used which can be removed by heat or solvent after the joint has been formed. Intermediate 0-rings (Figs. 15 and 16) may be used, or an intermediate ring of rectangular section, or a wire helix (Fig. 18), or small particles of various shapes (Fig. 17). The tube-ends may be located against a porous ring (218, Fig. 19) and at least one metal ring (233, 234, Fig. 20) may restrain the joint. Metal tubes 240, 242, Fig. 21, with plastics liners 241, 243 may be joined with a collar 250 having a plastics lining 249 and restrained by a spring 251 which may be spot-welded at 252, 253 to the collar. In a similar construction (Fig. 23) the collar (213) is provided with an internal locating shoulder (259) for the tube ends, the shoulder being a part of the collar or a separate metal or plastics ring. The coupling collar may be restrained by internal circumferential beads (277a, 277b, Fig. 29) on a ring co-extensive with the coupling collar (268). Alternatively, a restraining helix (279, Fig. 31) may be spotwelded to the collar, or adjacent end-turns of the helix may be spot-welded together. A plastics or metal tube (289, Fig. 25) may carry the restraining rings (290, 291). The coupling collar 297, Fig. 26, may be inserted inside the tube-ends 295, 296. This construction may be used for lined tubes (Fig. 27), when a sealing sleeve (308) is placed between the tube-ends and the collar. A restraining helix (311, Fig. 22) may be carried by a thin-walled metal or other tube 310. A further restraining means, Fig. 30, comprises fibres 319 of metal, plastics or glass supported on a metal or plastics tube 289 and/or surrounded by a plastics body. The restraining means may be made of metal, plastics, glass fibres or glass fibre impregnated plastics, and may be split into more than two parts if removable.