Patent GB-1141112-A (GB)
Title: Apparatus and method of joining together two strips of material
Inventor: WHEELER DONALD JAMES
IPC: B23K9/025
Filed: 1967-02-06
Abstract: 1,141,112. Seaming non-metallic sheet material. GUILD METAL JOINING EQUIPMENT CO. 6 Feb., 1967 [3 March, 1966], No. 5538/67. Heading B5K. [Also in Division B3] Apparatus for joining the ends of two strips of material comprises a frame, means carried by the frame for clamping two strips in a shearing position, a carriage, means mounting the carriage for transverse movement across the strips, a support member pivotally mounted on the carriage, a pair of shear knives attached to one end of the support, strip joining means attached to the other end of the support member and means for pivoting the support member to bring the shear knives into strip pass height and automatically retract the strip joining means and vice versa. A strip of plastics is advanced by drive rolls 92 and the strip is stopped at a predetermined distance from its end whereupon an exit clamp assembly 76 is actuated to secure it. A new strip B is fed into the apparatus by a feed roll assembly 94 and when the length of scrap to be cut therefrom is determined it is stopped and secured by an entry clamp assembly 75. Initially an upper feed roll 95 is at strip pass height with an intermediate roll 98 in contact therewith. With strips A, B clamped, upper and lower shears 10, 11 are positioned at strip pass height and shear assembly carriages travel across the strips, the scrap therefrom being deposited in a scrap cart 55. The shears are then retracted by pivoting arms 40 so as to move planish rolls 70, 71 into position. The clamp assembly 75 is indexed to provide the required gap or butt joint between the strips A, B and a weld back-up bar 107 is swung into position. The bar 107 acts as a lower electrode during welding, which is performed by actuating a carriage 61 carrying a torch 60. Alternatively the bar 107 may be replaced by a copper wheel or an additional torch could be mounted on a lower carriage. As the torch 60 is returned it is followed by the rolls 70, 71 which smooth out the joint. The clamp assemblies 75, 76 are opened, the assembly 75 is indexed to its original position and the rolls 70, 71 are retracted to bring the knives 10, 11 at strip pass height. The roll 98 is lowered to free the strip B in the assembly 93 and to engage a strip C in co-operation with a lower roll 95. The strip C is raised to strip pass height as soon as the trailing end of strip B clears the assembly 93. In an alternative apparatus (110), Fig. 7 (not shown), bell crank arms (130), (131) support slitter shear blades (132), (133) at one end and copper mash seam electrode wheels (134), (135) at the other end. The exit clamp assembly (150) is preferably mounted for horizontal indexing and the entry clamp assembly (149) has provision for vertical movement to facilitate overlapping of the strip ends, Fig. 8 (not shown). In a further construction of the apparatus a pair of rotary knives 163 are mounted at one end of a pair of pivoted arms 162 and a welding torch 170 is mounted at the other. The strips are held in clamps (173), 174 and their ends are trimmed by the knives 163 in co-operation with stationary shear knives (175), (176), Fig. 10 (not shown), as a carriage 160 is traversed. After shearing, the knives 162 are raised and the torch 170 lowered and as the carriage 160 is returned the strip ends are welded together. A weld back up bar 179 presses the strip ends against the clamps during the welding operation and a cutting tool 187 removes the weld bead. Alternatively the weld may be smoothed by a milling or multi-cutting tool or by planishing rolls. In all forms of the apparatus the strips may be joined by rolls which form a mechanical joint rather than a weld joint.