Patent GB-1201202-A (GB)
Title: Improvements in or relating to welding of tubular blanks
Inventor: POWELL IVOR JOHN
IPC: B23K9/025
Filed: 1967-05-16
Abstract: 1,201,202. Welding by pressure. WALTER SOMERS (MATERIALS HANDLING) Ltd. 5 Aug., 1968 [16 May, 1967], No. 22549/67. Heading B3R. An apparatus for feeding a tubular blank to a welding assembly comprises a flexible band for embracing the bight of the blank, the band being movably carried. A carriage 10, Figs. 1, 2, movable along horizontal rails 11, comprises a base 15 carrying guide members 19 on which the main portion 21 of the carriage is vertically movable. The vertical movement of the portion 21 is effected by a pneumatic cylinder 29 pivoted to the portion 21 and causing, through linkage, the rotation of shafts 35, 47 extending across the carriage and carrying at their ends levers which engage abutments 41, 51 carried by the base 15. A pair of identical arms 52 each comprising four plates 53, 54, 55, 56, with semi-circular recesses 71, spaced apart by tubular members 58, are pivoted about horizontal axes 59, each arm having a sprocket 60 driven by an electric motor 63 through gearing and a chain to rotate the arms from an inoperative position (in claim lines in Fig. 2) to an operative position (in full lines in Fig. 2). A flexible band 75 is entrained around rollers 74 mounted on the arms 52, the ends of the band 76 being connected to springs 77 anchored at 78 to the arms and on each arm three pneumatic jacks 79 are pivoted to operate eccentric clamping devices which clamp the band ends between sleeves 85 and channel members 72. Pneumatic jacks 91 operate tapered plug devices which lock the arms 52 in their operative positions and the springs 77 may be replaced by fluid pressure devices. The carriage described above is used with a welding machine 100, Fig. 5, having roller electrodes 101, 102, and a support assembly 103a. The support 103a comprises a column 104 carrying a rotatable head 106 with four supports each comprising curved members with a plate secured to one to provide a slot between the underside of the plate and the upper surface of the other. A series of rollers 124 are mounted between plates 123 secured to the upper surface of the plate and notches are provided in the plates 123 to receive one end of a sheet-metal blank, the other end being received in the slot. In operation, a tubular blank 126 is inserted by hand or automatically on support 107 so that the edge portions of the blank are overlapped and spaced vertically. The arms 52 of the carriage are opened to inoperative position with the carriage in position 110, Fig. 5, the support 107 is brought into a position adjacent the carriage and the arms 52 are moved to their operative closed positions when the band 75 embraces the blank and urges the ends of the blank into the notches and slots of the support. The band is clamped and the arms are locked in position. The carriage is then advanced towards the welding machine 100 moving the edges of the blank between the rollers 101, 102 which weld the edges together. When the whole of the blank is welded the carriage is in position 111 (Fig. 5), the portion 21 of the carriage is raised by operating cylinder 29 so that the upper part of the blank is above the rollers 124. The carriage is then moved to the right in Fig. 5 to thread the blank over the rollers 124, the band 75 is released, the arms 52 are moved to inoperative position and the support 106 is indexed to bring another blank to the carriage. The band may be of woven wire, reinforced canvas or fabric. The support may be arranged so that the blank edges are initially overlapped more at the end remote from the open end of the support.