Patent GB-1228979-A (GB)
Inventor: PIGNAL EDMOND
IPC: B23K9/032
Filed: 1968-10-22
Abstract: 1,228,979. Making finned tubes; welding by fusion; coiling. SOC. DES FABRICATIONS BIRAGHI-ENTREPOSE. 22 Oct., 1968 [23 Oct., 1967], No. 49953/68. Headings B3A, B3E and B3R. Apparatus for manufacturing gilled or finned tubes comprises means for supporting and rotating the tube 5, means for guiding and applying around the tube the edge of a strip unwound from a spool, a support to hold a welding torch or electrode and means for displacing relative to the tube and parallel to the axis of the tube the strip guide means and the torch or electrode support, the tube being connected to one pole of the welding current source while the other pole is connected to the electrode torch, and in which means for guiding the strip comprises a vertical angularly adjustable platen secured to a carriage 2 of the machine said platen carrying at least one vertically adjustable grooved pressure roller for engaging the top edge of the strip, two horizontal guide rollers for engaging the upper and lower edges of the strip and two vertical guide rollers for engaging the two faces of the strip. The carriage 2 supports tables 2a, 2b the table 2a carrying a guide system for the strip 8 and table 2b the support for the welding torch. The strip unwound from a spool 9 is carried by a guide 231 to an assembly 11 carrying the guide rollers and then to an assembly 10 carrying pressure rollers with which a welding head 12 is associated. An assembly 13 comprising adjustable rollers 106 (Fig. 14) supports the tube at the points where the strip engages the tube. The welding head comprises a refractory electrode 76 or a plasma arc torch which causes simultaneous fusion of the edge of the strip and the formation of a groove in the tube surface and the pressure rollers apply the strip against the tube to form the weld. The assembly 10 carrying the pressure rollers comprises a vertical platen 14 mounted on a plate 15 pivotally mounted on the table 2b (Fig. 4). The two-part pressure rollers 41a are mounted in a carrier 30 vertically adjustable by means of a screw-threaded rod 48 rotated by a handle 51. A graduated scale ensures accurate readjustment of the pressure rollers. The assembly 11 carrying the guide rollers comprises a plate 52 carrying an adjustable roller 56 (Fig. 6, not shown) and a plate 70a carrying a guide roller 74. Adjustable vertical rollers 92 (Fig. 13) engage each face of the strip 8 to maintain the strip perpendicular to the tube. The welding head assembly 12 (Fig. 18) comprises a vertical platen 122 mounted on the table 2b of the carriage 2. The torch-carrying assembly 121 is secured to a plate 154 mounted on horizontal rods 145 the plate being movable horizontally by means of a knurled knob 148 rotating a screw-threaded rod 147. The plate 154 is also mounted for vertical adjustment by means of screw-threaded rod 128 (Figs. 18 and 19). A sleeve 165 mounted on the plate 154 rotatably carries a member 166 provided with a handle 167 and a rod 168 which is screwed into a sleeve 169 having a tubular attachment 170 for a torch holder which can be longitudinally adjusted by means of a rack and pinion in a casing 174 operated by knurled knob 175. Graduations on a collar on the torch holder enable the torch to be accurately inclined to the axis of the tube. Contactors comprising pairs of contacts operate warning lights should the welding torch be displaced from its vertical or horizontal setting and the electrical circuits of the welding torch and the motors causing rotatation of the tube, displacement of the carriage and passage of the strip are also broken to stop the machine.