GB791046A - Improvements in and relating to a machine for helically winding metal sheets or plates in particular for producing tubes - Google Patents

Abstract

791,046. Coiling helically jointed tubes; welding by pressure. COMPAGNIE DE PONTA-MOUSSON. March 1, 1956 [March 7, 1955; June 21, 1955; Feb. 6, 1956], No. 6434/56. Classes 83 (2) and 83 (4). A machine of the anvil and punch type for producing tubular objects, such as pipes, by helically winding metal sheet or plate is characterized in that the punch simultaneously effects the feeding and the bending of the sheet. Metal sheet t is guided by roller means G to a polished cylindrical anvil 5, extending from a block 5a and cut away at 5b, on to which it is bent and helically around which it is simultaneously fed by a concave faced punch 6 reciprocating along an axis Y-Y offset from the anvil axis. The punch 6 is guided by a roller slide 20 and is carried by a double-acting hydraulic piston 7,' the supply of fluid to which is controlled by a cock 11 the key of which is secured to a plate 16 oscillated by a link 18 from a motor 19. The tangential component of the bending force feeds the sheet around the anvil 5 to pass between the bottom face of the anvil and a polished die 4. The thus-coiled tube T is guided by rollers 22, rotatable about axes perpendicular to the tube axis, in a ring 21 itself rotatable on balls 23 in a fixed frame 24. The frame 24 carries an electrode 25 for welding the helical seam. In a modification, Fig. 5, the anvil 5, which is of part cylindrical shape, lies above a punch 34 carried on a plate 35 reciprocated by a crank-plate 42. To join two sheets end to end for coiling, the inner weld bead on the upper face of the sheet may be effected at the input side of the machine and the outer weld bead at the output side of the machine. In another modification, Figs. 9, 12 and 13, the guide ring 21 is dispensed with and the tube is spot welded as it is formed. An electrode 46 spring-mounted on the output end of the punch 6 co-operates with an electrode 52 in the anvil 5. The electrodes 46, 52 are connected to the secondary winding 51 of a transformer Tr, to the primary winding 55 of which current is supplied on closing a switch 57 operated by a relay 58 upon the closing of a further switch 60, 61. The switch 60, 61 is closed by a boss 62 on the oscillated plate 16 so that a weld is effected at the end of each stroke of the punch 6 towards the anvil 5. The guide ring 21 may be rotated by a motor. The axis Y-Y of the punch 6 may be oriented in any direction. The punch 6 may be actuated by several rams.