Patent GB-843242-A (GB)
Title: Improvements in or relating to electric resistance welding operations
Inventor: HUGHES WILLIAM J
IPC: B23K11/30
Filed: 1958-05-05
Abstract: 843,242. Making aneroid capsules; welding by pressure. BENDIX AVIATION CORPORATION. May 5, 1958, No. 14316/58. Classes 83 (2) and 83 (4). In a machine for resistance welding articles, e.g. aneroid capsules, in a vacuum or non- oxidizing atmosphere having two electrodes, one electrode supports the work, each electrode is mounted in a framework forming part of a welding chamber and one electrode is movable relatively to the other. In an embodiment the machine comprises a base 10 in which is mounted a vertically reciprocable shaft 11 carrying at its upper end a support, formed by a plate 16 and a ring 17, for a lower dish-shaped electrode 35. The electrode support is sealed to an upstanding ring 19 on the frame by a flexible annular sheet 21 so that a chamber 32 to which pressure air may be admitted from a pipe 34 is formed beneath the support. The ring 19 forms part of the wall of the welding chamber 15. The shaft 11 is normally urged downwardly by springs 29 acting between the frame and a collar 26 on the shaft and cooling water is supplied to the plate 16 by pipes 40, 41 and passages 38, 39 in the shaft. The upper part of the wall of the welding chamber is formed by a ring 51 secured to the lower end of a member 50 forming the upper electrode support. A block 57 is rotatably mounted in the member 50 and carries a non-rotatable shaft 59 at an angle to the block axis. The shaft carries a head 64 which is sealed by a flexible sheet 77 to the ring 51 to complete the top of the chamber 15 and the upper dish-shaped electrode 72 is carried in a holder 65 in the head 64. The holder is cooled by water supplied by a pipe 70 and passages 68 in the shaft 59 and a spring-pressed pin 73 is provided in the head 64 to engage the article to be welded. To prevent rotation of the head 64 a rotatable crank arm 80 in the member 50 engages a socket in the head and a gear-wheel 55 on the block 57 is rotated by a motor unit 81 so that the shaft 59 is moved in a cone-shaped path. The secondary of a welding transformer is coupled to a sleeve 43 on the shaft 11 and to a sleeve 90 on the shaft 59. The upper electrode support &c. has lugs 93, 94 slidable on upright guide rods 91, 92 and the support is attached for vertical movement to the rod of an airpressure piston in a cylinder. In operation a pair of shaped aneroid diaphragms are placed on the lower electrode with their flanges in contact. The operator closes switches so that automatically air is supplied to the top of the piston to move the upper support down thus closing the ring 51 on to the sealing ring 79 in the ring 19 to close the chamber 15, air is exhausted from the chamber 15, current is supplied to the motor 81 to rotate the block 57, water is supplied to the electrode holders, air is supplied to the chamber 32 to raise the diaphragms into contact with the upper electrode which " walks " around the flanges, and welding current is supplied to the electrodes so that a seam weld is effected on the flanges of the exhausted aneroid capsule. Then after a timed period the welding current is cut off, the work is lowered, the drive motor 81 stops, the evacuation of the chamber 15 ceases and the upper support &c. is raised. After evacuation of the chamber 15 an inert gas may be supplied thereto.