GB1042271A - Gripping jaws for gripping sheet metal - Google Patents

Abstract

1,042,271. Stretch forming; drawing press. CYRIL BATH CO. June 13, 1963 [June 13, 1962], No. 23536/63. Headings B3E and B3Q. A stretch forming machine includes at least one gripping head having a pair of jaws to hold and stretch the sheet, the jaws having on respective gripping faces thereof respective sets of parallel gripping ridges, the lengths of which extend on one of the jaws in a direction which is oblique and to one side of the direction of tension applied to the gripped portion of the stock, and on the other of the jaws in a direction which is oblique to but extends to the other side of said direction of tension. Sheet S is stretched by means 11 over a former 5 and is then formed by a die 6, Fig. 1 (not shown). Each means 11 includes a gripping head 12 mounted on a carriage 13 running on rollers 16 and moved back by hydraulic pistons 22 rocking a link 17 connected to the carriage. The head 12 carries an upper jaw 30 and a lower jaw 31 opened and closed by a hydraulic piston 51 and rod 52 and wedge surfaces 36, 46 on the head. The gripping face of the upper jaw is formed with a series of parallel ridges or teeth 62, Fig. 12 (not shown), and that of the lower jaw with a series of parallel ridges or teeth 64. The ridges are inclined at an angle of 45 degrees to the direction of tension 63 with the ridges 62, 64 lying across one another. The ridges may be curvilinear. A side gripping head 70, Fig. 13 (not shown), has jaws 71, 72 with their ridges crossing.