GB276664A - Improvements in or relating to electric arc and resistance welding apparatus - Google Patents

Abstract

276,664. British Thomson-Houston Co., Ltd., (Assignees of Chapman, V. J.). Aug. 30, 1926, [Convention date]. Fluid-pressure presses.-A pressure member for clamping the work in an automatic arc welding machine or for applying pressure to the electrodes of a resistance line welding machine is prevented, by movement of a brace for connecting the two abutments between which it acts, from being actuated until the brace is in operative position. The welding head 11 of an arc welding machine for welding the longitudinal seams of tanks is traversed by a motor on a track 7 over a pair of beams 5 mounted on frame members 1, 2 and carrying jaws 15 against which the work is pressed by a backing member 12 forced upwards by plungers 13 operated by distensible hose 14 supported on a beam 6 which is fixed at 16 to the frame. The other end of the beam is supported during operation by a latch bolt 17 which. is pivoted on a shaft 27 provided with a link 23 controlled by a spring 26 to hold the bolt both in its open and closed positions. The link is connected by links 24, 25 to a valve 22. Fluid pressure is supplied to the hose through a valve 18 and also communicates with the valve 22 through a by-pass 21. When the bolt is open the fluid is by-passed through the valve and so the pressure member 12 is rendered inoperative, but when the bolt is closed after insertion of the work the valve 22 is closed thereby and the fluid passes into the hose. A similar bolt 59, Fig. 3, together with links 60, 58, 57 and valves 56, 54, is used to control the pressure which passes through theflexible hose 52 to the upper roll electrode 36 of a resistance welding machine. The electrodes 36 are mounted on wheeled carriages traversed on the arms 31, 32 so as to weld work such as a tank 34 secured by lamps 35 to the arm 32. The carriages are connected by arms 47, 48 to the carriage of a motor 37, which through gearing 39 - - 42 is traversed along a fixed rack 38. Specification 275,197, [Class 39 (iii), Heating by electricity], is referred to. The Specification as open to inspection under Sect. 91 (3) (a) states that the invention is applicable to devices for applying pressure other than welding machines. This subject-matter does not appear in the Specification as accepted.