GB350292A - - Google Patents

Abstract

350,292. Welding. BUDD MANUFACTURING CO., E. G., 2500, Hunting Park Avenue, Philadelphia, U.S.A.-(Assignees of Hanson, A. F. ; 2500, Hunting Park Avenue, Philadelphia, U.S.A.) July 14, 1930, No. 21287. Convention date, Aug. 8, 1929. [Class 83 (iv).] In a welding machine, particularly for flash - welding long seams in metal sheets, e.g. of the order of 100", dies of corresponding length are used, the ends of the movable die being connected by parallel movement mechanism so as to ensure uniform movement thereof. The sheets 12, 13, Fig. 2, are placed on the dies 10, which together with electromagnetic blocks 14, are carried by frames respectively mounted between and secured to fixed and movable pairs of pillars 21, 25, Fig. 1, the sheets being clamped by the parts 17, 18 of armatures 15 controlled by a hoisting mechanism operated by fluid-pressure motors 20. The pillars 25 are each secured to a beam 26 slidable in one of the pillars 21 and also in a support 28. The beams are operated to cause approach of the dies by a pair of hydraulic motors 39 provided with reciprocating cams 35 engaging followers 36 on bell cranks 32 connected by links 33 to the beams. The bell cranks are mounted on a common shaft 41 to form a parallel movement mechanism, so that the beams move in synchronism irrespective of the differential resistance due to varying mechanical and electrical conditions in the machine. The motors are synchronized so that the motor having the lower load helps out that having the higher load. For this purpose the pistons 43 are extended outwardly and are provided with a pair of racks 42 engaging pairs of pinions 43<1> on parallel shafts 44. The movable die is retracted by a pair of fluid-pressure motors 46, the supply of fluid to which is conveyed through check valves 48, which are opened during approach of the dies and are closed for retraction thereof. The fluid for operating the motors passes through small ports 49, Fig. 5, so that the movement of bell cranks lags behind the receding movement of the cams 35 under the action of the reverse movement of the motors 39, so as to release the cams of heavy pressure and permit the motors to retract them quickly to starting position. The motors 39, 46 are both governed from a valve 50 by a lever 51. Gauges 52, 53, Fig. 4, of different thickness are initially inserted between the sheets to position their edges divergently, so as to arrange them suitably for a perfect starting and continuation of the arc. These gauges are mounted on shafts 54 and are moved into position by handles 56 and returned by springs 57.