GB411703A - Improvements in or relating to methods of and apparatus for welding and like operations - Google Patents

Abstract

411,703. Electrically-actuated valves. LINDE AIR PRODUCTS CO., 30, East 42nd Street, New York, U.S.A. July 24, 1933, No. 20794. Convention date, Aug. 24, 1932. Addition to 393,411. [Class 135.] In a process of progressively welding a seam or depositing metal on a surface by electric or gas welding or both, the heat applied to the progressively added metal rod or wire prior to welding, is varied proportionately to changes in radiant energy emitted by the added metal. The work W is traversed under a welding rod D and preheating and welding blowpipes B<1>, B by rolls F, driven by a variable speed motor M, the rheostat H in the field of which is controlled by worm gear 29 through a reversible motor K, itself controlled by switches 27, 28 operated by solenoids 21, 22, through a battery 19 and the pointer 16 of a milliameter, due to fluctuations of current in an amplifier A connected to a photo-electric cell C focused on the work in the welding region as described in the parent Specification. The welding rod is fed by rolls 30, 31 in synchronism with the work through a preheating blowpipe 37 by bevel gear 35, 34, 36 from the rolls F so that the quantity of metal supplied for a unit length of work remains constant. In order to keep the temperature of the added metal constant in spite of variations in the feed and thus to keep the temperature of the welding puddle constant, the gas and oxygen supply pipes 12, 13 contain byepasses 71, 72 provided with valves 73, 74 which are connected to the core 76 of a solenoid 75, which is energized in one or the other direction by a battery 77 through contacts 79, 80 co-operating with an arm 78 on. a coil 87 controlled by a photo-electric cell 84 through an amplifier 86. Hand operated valves 69, 70 are set so that the supplies of gas and oxygen correspond with the lowest welding speed. Further hand operated valves 89, 90 are provided with byepasses, and similar valves 91-94 are provided in the pipes 12<a>, 12b, 13<a>, 13b connected with the blowpipes B, B<1>. In a modification, automatically operated valves 102, 103 are controlled by speed gear 120-122, and worm gear 118, 117 from a reversible motor K<1>, which through switches 110, 111, solenoids 108, 109, battery 77, contacts 104, 105 and the arm 78 on the coil 87 of a milliameter, is controlled through an amplifier 86 by the photo - electric cell 84. Manually operated valves 100, 101 are also provided.