Patent GB-541406-A (GB)
Title: Improvements in and relating to methods of and apparatus for corrugating metal tubing
IPC: B21D15/10
Filed: 1940-04-18
Abstract: 541,406. Corrugating tubes. CHICAGO METAL HOSE CORPORATION. April 18, 1940, No. 7045. Convention date, Oct. 23, 1939. [Classes 83 (ii) and 83 (iv)] In corrugating plain metal tubing, particularly for flexible bellows tube, each corrugation is formed separately in two steps by first displacing radially, by pressure exerted uniformly circumferentially of the tube, a substantially annular section of the tube to form the beginning of the corrugation and immediately thereafter and prior to axial shifting of the tube continuing the formation of the corrugation by relative axial movement towards each other of the sides of the radially displaced section, after which the tube is moved axially through a predetermined distance and the process repeated. The tube 60 is held by a pair of grooved jaws 11, 12 closed by levers 43 operated by cams on a shaft connected by spur and bevel gear to the driving shaft 17. The rear grooved edge of the jaws cooperates with the front grooved edge of a die 13 to form the corrugation. The die 13 is reciprocated through toggles 27, 28, links 26 adjustable on slotted arms 24, and cams 22 on a shaft 21 connected by spur gear to the main shaft. The die co-operates also with an inner member 14 which comprises a metal sleeve 57, a rubber sleeve 71, a metal washer 72, a rubber washer 73 and a second metal washer 74 all loosely mounted on a control shaft 15 and held thereon by a washer 75 and nut 76. The sleeve 57 is operated by a lever 54 through a cam 52 on a shaft 51 geared to the shaft 36, and the shaft 15 is operated by a lever 58 from a cam 53 on the shaft 51. The die 13 contains a rubber sleeve 69 which co-operates with the sleeve 71 to feed the tube forwards. When the tube is held by the jaws 11, 12, Fig. 11, the die 13 and member 14 are moved forwards together. The sleeve 57 moves forward relatively to the shaft 15 and the sleeve 71 is expanded so as to push the rear of the tube forwards and the sleeve 73 is expanded so as to initiate the formation of a corrugation 81. Then the shaft 15 is moved forward so that the sleeves 71, 73 are released from the tube and the corrugation is completed by movement of the die 13, Fig. 13, the parts 14, 15 moving forward at the same time. The parts 14, 15 are then retracted and the die 13 then retracted. The jaws 11, 12 are then opened and the shaft 15 is then urged lightly against the parts 14R to compress the sleeve 71 but not the sleeve 73 which is of harder material. The parts 13, 14 are then moved forward simultaneously to feed the whole tube forwards one corrugation. If desired the shaft 15 may be held stationary so that the rubber sleeve 73 may be operative throughout the corrugating operation. The corrugations may be reduced in pitch and deepened by rollers 100, Fig. 18, formed with flanges of progressively decreasing pitch and increasing height. These rollers are carried by radially movable slides in a head 97, Fig. 16, rotated by a belt 99 from the shaft 39. The other ends of the slides are provided with conical rollers 103 and the radial movement is effected by a cone 104 connected to a lever 106 operated by a cam 108 on a shaft driven from an extension of the shaft 36. The roller head may be put out of action by a clutch preventing operation of the cam 108. The tube may consist of thin walled stainless steel and may have a non-corrugated cylindrical end section and the corrugations may either be continuous or separated by non-corrugated sections.