GB749402A - Improvements relating to sheet metal stretching machines - Google Patents

Abstract

749,402. Stretching; straightening. BIGWOOD & SON, Ltd., J. Dec. 7, 1954 [Dec. 7, 1953], No. 34012/53. Class 83 (4). A machine for stretching metal sheets having two opposed sheet-gripping devices relatively movable to stretch the sheet has mounted in front of the opening of the jaws of each gripping device a pair of rollers adapted to advance the sheet to insert its edge between the jaws. Two gripping devices 10, on wheeled carriages 11, grip the opposite edges of a sheet of metal 14 and on movement of one gripping device away from the other, by hydraulically operated means, the sheet 14 is stretched therebetween. To insert the edges of the sheet between jaws 12 of each gripping device, prior to stretching, the edge is inserted between upper and lower rollers 15, 16 mounted in front of the jaw opening of the gripping device, the lower roller 16 having been suitably adjusted vertically in accordance with the thickness of the sheet. Hydraulic units 19, the rods 22 of which are connected by a pin 23 to a beam 20 extending the length of the rollers, are then actuated to move the beam 20 downwards, thus moving the upper roller 15, which is journalled in the ends of the beam and is backed by bearings 21 along its length, down onto the sheet 14. The roller 15 is then rotated, through gearing 26, 27 by a handle 29 or by power means, to feed the sheet edge to the jaws 12 which then move to grip the edge and the hydraulic pressure on the roller 15 is released. The roller 15 may be rockable about a horizontal axis to adjust itself to unevenness of the sheet across its width. Specification 614,186 is referred to.