GB966747A - Improvements in or relating to machines for working sheet metal - Google Patents

Abstract

966,747. Stamping; angular bending; shearing. COOKSON SHEET METAL DEVELOPMENTS Ltd. April 20, 1961 [May 19, 1960], No. 17768/60. Headings B3E, B3Q and B3W. A sheet metal working machine having co-operating press tools to receive an end portion of a ribbed metal sheet and adapted to deform and shape that end of the sheet to close the ends of the ribs and leave a flat margin at the ends of the -ribs has means for bending the flat margin to form a laterally extending flange at the edge of the sheet and means for trimming the free edge of the margin. The machine is provided with a horizontal table 24 and a ram plate 27 carried by the rams of two vertical hydraulic cylinders 28 and 30 is reciprocable between frames 14 and 16. A first wiper plate 42 is slidably mounted in guides 38 and 40 and actuated by an hydraulic cylinder 44. On the table 24 two side guides 46 and 48 slidably accommodate a second wiper member 50 actuated by an hydraulic cylinder 52. Sliding cams 54 movable with the member 50 raise or lower the slidable backing plate 56 under the front edge of the bed plate 32. A guillotine knife 58 is provided on the top edge of the second wiper member which co-operates with the top edge 60 of the plate 56. Three male tools 62 are mounted on the bed plate 32 and corresponding female tools 64 are mounted on the ram plate 27. The tools co-operate to deform and shape the end portions of the ribs 76 of the roofing sheet 72 to close the ends 78 and leave a flat portion 82 which is first bent downwardly and then inwardly, Fig. 5. In Fig. 8 the tools are shown closed over rib 76 with the cams 54 holding the backing plate 56 in its operative position in recess 94. The wiper plate 42 is actuated to bend down the flange 82 after which the second wiper plate 50 is moved forward and the top edge 100 of the plate bends the flange 82 around the support piece 95, Fig. 9. Before bending the flange the knife 58 and bit 60 trim off the surplus and ragged edge of the flange. Roofing sheets having trapezoidal ribs, Fig. 11, are shaped to close the ends of the ribs by means of a machine according to the invention. In this embodiment the slanting sides 108 of each rib are folded inwardly under the top portion 110 so forming pleats 113. Instead of the hooked flange 116 a downwardly directed flange 118 may be formed. A pleat controlling device 140 is mounted on a bridge plate 142 secured to the machine table 24. The device comprises a spring-loaded swingable arm 148 to which is attached a support 150 having two downwardly directed prongs 152, Fig. 15. During the rib closing operation the prongs 152 inwardly press sides 108 of the rib 106 to kink them as at 160 to ensure that the edges of the rib start to make uniform folds to form the pleats 113.