| 摘要 |
1,132,648. Flattening, straightening and stretching metal sheets &c. SANDVIKENS JERNVERKS A.B. 4 March, 1966 [6 March, 1965], No. 9556/66. Heading B3E. Metal sheets are straightened by stretching whilst restraining movement normal to the surface of the sheet to prevent buckling. The sheet 10 is gripped by self-tightening stretching heads 13, 14 comprising jaws having eccentric projections (16, Fig. 3) and stretched by force exerted on the head 14 by an hydraulic piston and cylinder 27. Movement normal to the surface of the sheet is restrained by slabs 11, 30, the upper slab 30 of which may lie directly on the sheet 10 or may be spaced from it by screws (35), Fig. 2 (not shown). An arrangement for lifting the upper slab 30 clear of the machine (Fig. 2) comprises an hydraulic ram (34) which lifts the slab 30 through a pivoted arm (33). The slabs may each be formed in a single piece or may be formed by assembling short slabs to the requisite length for the sheet to be stretched. The slabs may have plane surfaces to form flat sheets or may have curved surfaces to stretch materials with a curved cross-section. In another embodiment (Figs. 4 and 5) the slabs are replaced by a trellis formed of girders 36 and beams 37. In another embodiment (Fig. 6) the sheet is restrained by a plurality of rollers (50, 51) and the sheet is stretched by clamping it to two rollers (54, 55) one of which is rotatable to tension the sheet. |
