GB1336751A - Method and device for folding sheets such as drawings - Google Patents

Abstract

1336751 Folding sheet material OCE-VAN DER GRINTEN NV 23 April 1971 [24 April 1970] 11041/71 Heading B8R Apparatus for zig-zag folding of sheets such as drawings, the number and position of the folds being dependent on the length of the sheets and in a particular fold pattern according to standard Dutch or German practice, comprises folding mechanism including a leading edge detector D0 and a plurality of trailing edge detectors D1-D8 spaced along an infeed path. At the moment the leading edge reaches the detector D0, the highest numbered detector which is covered by the sheet indicates that the sheet has a length range defined by the distances from the detector DO to the said covered detector and the adjacent next higher and uncovered detector, while the time taken as the sheet is advanced before the trailing edge uncovers said covered detector is an indication of the residual length of sheet over and above the lower limit of the length range, and is measured by a counter counting pulses emitted by a pulse sender at a frequency proportional to the feed speed. The folding device may comprise feed rollers 7, 5 and a curved guide channel 6, a guide member 4 displaceable between two positions, and two reversible folding roller pairs 1, 2, whereby, the rollers being reversed as the member 4 is displaced, the sheet is successively forced between each pair of rollers 1, 2. The members 4 and rollers 1, 2 are controlled through an electronic circuit in response to the sensing of the sheet by the detectors D0-D8 and the counting of the pulses.