Patent GB-337329-A (GB)
Title: Roller folding machine for the manufacture of bulked or loosely folded envelopes
IPC: B31B150/00
Filed: 1930-02-26
Abstract: 337,329. Winkler, A., and Dunnebier, M. July 5, 1929, [Convention date]. Envelopes, making. - In a cylinder machine for making " bulked " or looselv folded envelopes, the creasing knives are formed with blunt rounded edges, and the cylinders, discs and rollers which effect the conveyance, folding and sticking are in part cut away or of conical form, in part composed of separate parts which are longitudinally displaceable on their shafts, and in part are capable of being raised or lowered to avoid sharp pressure on the folds, provision also being made for regulating the looseness of the folds. Blanks drawn by rollers 1, 2, Fig. 1, and straightened by fingers 3, 4 receive blunt creases when engaged by blunt knives 7 mounted on separate sectors of a roller 6, the sectors being adjustable to and from each other for different sizes of envelopes. Swinging lifters 12 bend up the side flaps over folding rails 14, adjustable for width, as the blank approaches rollers 10, 11 adapted to feed it to folders 19 by which the folding is completed. By altering the cross section of the rails 14, the looseness of the folds may be adjusted. The folds thus made have to pass through the machine without being pressed, and to allow for this, the roller 18 of the next pair of feeding rollers comprises short central rollers 22, Fig. 3, and adjustable rollers 23, the operative portions of which are made conical, and the next roller 20 is recessed to accommodate the folds. Gum is applied to the side flaps in known manner by sectors 25. Rollers 33, 34 now feed the gummed blank to the device for folding over the bottom flap, the roller 34 being grooved to correspond to the gummed portions and comprising a fixed central and adjustable side portions to avoid pressing the folds. When the central and side rollers are contiguous, their total width is less than the distance between the side flap folds of the smallest blank to be operated on. A tucker 42 tucks the bottom flap between rollers 40, 41 which fold it over and stick it down. The roller 40 comprises a central portion 45 and adjustable side portions 46, Fig. 7, having their surfaces formed with interesting grooves to avoid squeezing out the gum, and outer rollers 47 between which is mounted a presser bar 49, the bar being arranged to co-operate with a recess 44 in the lower roller 41 to prevent sharp pressure on the bottom fold. One side of the recess is inclined to permit adjustment of the pressure. Throughout the operation, steady pressure is exerted on the folded parts by a rubber covered portion 51 in the middle of the central roller 45. In known manner, a pivoted plate 52 guides the partly formed envelope upwards and then downwards with its unfolded flap foremost preparatory to a blade 54 tucking the flap between rollers 53, 41 which fold it over, the roller 53 being recessed to prevent undue pressure on the folds. An inclined plate 58 guides the envelope to a pair of conveyer discs 59 having stops 62 which push the envelope along a curved guide 61, guide rollers 60 between the plate 58 and guide 61 being raised for the passage of the closure flap fold by a lever 70 and cam 73. An extension 75 of the lever 70 engages an adjustable stop 77 which prevents the roller from falling into recesses 74 formed in the discs 59 and adapted to receive the rear fold of the envelopes. A flier 64 places the envelope against a pair of delivery discs 65 which pass it on to a conveyer 63.