Patent GB-1390264-A (GB)
Title: Methods of and apparatus for protecting sheet material
IPC: B65B23/20
Filed: 1972-09-08
Abstract: 1390264 Protecting sheet material NIPPON STEEL CORP 8 Sept 1972 [29 Oct 1971 6 Dec 1971] 41881/72 Heading B8C In a method of providing pieces of sheet material such as steel, aluminium, or glass, each with a protective layer, for example, of paper, or plastics, a continuous sheet, made for example of steel, is sheared at 4, into individual sheets 2 which are passed successively to an inspection conveyer 5, a switching conveyer 6, where rejected sheets are fed to an upper conveyer over a roll 26 and a guide 27 to a conveyer 29 which sends the sheets to a stacker 8, pinch feed rollers 11, 11<SP>1</SP> on a frame 12, advancing, in sequence with the sheets 2, lengths of, for example paper sheet corresponding to the length and speed of each sheet 2 as measured by the device 30. As the leading edge of a sheet 2 is sensed by the detector 30 a clutch 12, Fig. 4, driven by the drive pulley of the conveyer 6, is engaged, and a brake 13 is released to drive the pinch roll 11 which cooperates with the associated spring-loaded roll 11<SP>1</SP>, and advance the paper sheet, unrolled from a relatively small-diameter supply roll (9<SP>1</SP>), Fig. 5A, or 5B, not shown, under back-tension, at the same rate as the advance of the sheet 2 toward the guide 27. The clutch 12 is disengaged and the brake 13 is reapplied when the trailing edge of the sheet 2 passes the detector 30 and the leading end of the paper projects, at the location of the guide 27, by a small amount, across the path of travel of the sheet 2. Simultaneously, a cutter ram 21, is operated to actuate by means of a toggle mechanism 20, a cutter blade 19 to cut off a length of paper which is slightly longer than the sheet 2. The distance from the cutter 7 to the guide 27 is less than the distance from the latter to the detectors 30. As the sheet 2 advances the projecting end of the paper is folded back against the upper face of the sheet 2 by a roller above the conveyor roll 28 the latter guiding the remainder of the paper sheet against the lower face of the sheet 2 as it is advanced to a vacuum conveyer 7 which deposits it upon a stacker 8, Fig. 2, If speeds of paper supply are required above 75 metres per minute a larger backtensioned roll (9), with an initial starting mechanism (43-45, 47), is employed in combination with a paper looping device which is located between the roll 9 and the feed rollers 11, 11, Fig. 6, not shown. The paper after leaving the supply roll 9 passes over an inlet roll 23, a guide plate 24, between the pinch rollers 11, 11<SP>1</SP>, and into a guide 25 supplied with air from a tube 33. In a further modification Figs. 9-11, not shown, the paper guide (114), is made of bendable material; alternatively it may be pivoted, and spring-loaded. The ram (120) for the cutter blade (107) may act directly upon the latter, and the toggle mechanism may be replaced by other suitable mechanism. In another modification, Figs. 14, 15, the roller 209<SP>1</SP>, which folds the edge of the paper over the upper edge of the sheet, has a reduced central portion b so that the folded end portion has the shape shown in Fig. 15, and so that it is unfolded by the next following sheet as the sheets are stacked . Alternatively, gas may be directed at the folded-back portion to unfold it.