GB1323213A - Method and apparatus for folding sheets - Google Patents

Abstract

1323213 Folding fabrics R L SJOSTROM 19 April 1971 [24 Feb 1970] 23187/71 Heading D1S In a method of folding, a sheet is advanced in a planar configuration, with one edge leading, along a path extending past a first pair of folding rollers until the nip line thereof and an intended fold line in the sheet are in register. The sheet is injected into the nip by air jet or blades to be drawn therethrough to effect a fold the line of which then defines a leading edge of further advancement beyond a second pair of folding rollers which, in similar manner (but by withdrawing the oncefolded sheet in the opposite direction) makes another fold. A compact, simple and readily transportable machine for folding washed and dried, "non-iron" bed and like sheets of finite dimensions may comprise a feeding unit and a receiving platform at a lower level and on the same side of the machine so that an operator loads and unloads the machine from the same position in preparation for manual or automatic cross-folding and/or normal usage. In the operation of the machine shown, Fig. 1, a sheet supplied to a pivotable feeding unit 22 by placing it on endless feeding belts 34 is gripped by means of pressure belts 42 and advanced over a loading bed 28. The leading edge drapes, Fig. 2, and advances downwardly past a folding unit 24 in front of folding rollers 112, 114, 120, 122. Air from a tube 130 injects the (arrested) sheet into nip line 128 to enable the rollers to make the first longitudinal fold which becomes a leading edge draping and advancing beyond the folding rollers on the opposite side thereof. Air from tube 140 injects the folded sheet onto nip line 138 whereby a second fold is formed and the quarter-folded sheet is ejected along a chute 144 to a loading platform. The advance and appropriate arrests of the sheet and the injection of compressed air are controlled by push-button and sheet-edge sensitive, trip feeler or filament actuated, adjustably and/or predeterminedly spaced (according to sheet size) microswitches which in turn actuate, for example, pneumatic valves. As shown in Fig. 8, a cross-folder 186 substituted for platform 26, delivers the fully cross-folded sheet laterally to a receiving station 188. In order to make the cross-folds, the folded sheet is advanced along a bed 190, its midportion is injected downwardly, by air pipe 214 (or a knife 216) through a slot 208 and into the nip line (212) of cross-fold rolls (210) which form a fold as they advance the sheet downwardly along a deflector 228 into belts 220 for transfer to a second cross-folding unit comprising a blade 244 and then a further cross-folding unit (250) whence the sheet is delivered to a table 252.