Patent GB-855182-A (GB)
Title: Improvements in or relating to a method and a machine for the production of envelopes
IPC: B31B160/10
Filed: 1957-12-12
Abstract: 855,182. Making envelopes. WINKLER, R., and DUNNEBIER, K. Dec. 12, 1957 [Feb. 4, 1957], No. 38616/57. Class 94(2). A method of producing envelopes comprises feeding preshaped envelope blanks to a rollertype creasing, folding, and gumming machine in closely overlapped formation with the bottom flaps to the fore in the direction of travel of the blanks through the machine, reducing the overlap of the blanks to such an extent as to enable the creasing of the bottom flaps to take place on a part of each blank which is not overlapped by a preceding or a succeeding blank, and whilst maintaining overlap of the blanks folding over the bottom flaps and uniting them to the folded down side flaps. As shown, envelope blanks 1, Fig. 1, with gummed closing flaps la are advanced in overlapping relationship. The blanks are drawn apart by rollers 2, 3, Fig. 5a, such that the successive spaces of the closing flaps are spaced a distance substantially equal to the sum of the maximum height of a finished envelope plus the height of the closing flap. Registering discs 4, 4<SP>1</SP> having pins 7, 7<SP>1</SP> feed the blanks between pairs of upper and lower guides such as 5, 6. Creasing rollers 8, 8<SP>1</SP> and 9, 91 then crease the side wings 1b, Fig. 1, while rollers 10, 11, Fig. 5a, crease the bottom flaps 1c, Fig. 1. The blanks are then successively re-arranged, such that the bottom flaps are positioned above the closing flaps by first spacing the blanks apart by passage past a segmental feed roller 15, Fig. 5b, while advancing the previous blank at a higher speed by. a segmental roller 16. Cams 19, 19<SP>1</SP>, Fig. 5b, rotatable with the roller 15 actuate leaf springs 18, 18<SP>1</SP> to press the closing flap 1a of a blank into contact with a plate 20 having a curved rear end, thus enabling the succeeding blank to be fed on top of the blank so held. Folding strips 24, 24<SP>1</SP>, then fold the side flaps inwards, the flaps being pressed downwards by a roller 25. The side flaps then receive a line 12, Fig. 1, of gum from a device 26, 26<SP>1</SP>, Fig. 5c, in known manner. The bottom flap is then folded on to the side flaps by folding cylinders 27, 29 and 30. The bottom flap is held by suction to the cylinder 27 and fed into a pocket 28 whereupon the suction cylinder 29 folds the blanks at the rear of their bottom flaps with the cylinder 30. Rollers 31, 32 feed the blanks forwards between leaf springs 39, 39<SP>1</SP> and a plate 40 which enable the front edge of the succeeding envelope to slide over the closing flap of the preceding envelope, the springs 39, 39<SP>1</SP> being rocked by cams 38, 38<SP>1</SP>. Roller 37, carrying abutments 37, 37<SP>1</SP> and driven at reduced speed, re-position the blanks after their passage through rollers 33, 34 which crease the closing flaps. The roller 34 is adjustable towards the roller 37 by means of racks 36, 36<SP>1</SP> and pinion 35. The closing flaps are then folded in similar manner to bottom flaps by folding cylinders 41, 43 and 45 and a folding pocket 44, the body of the envelope being fed into the pocket 44 by the suction cylinder 43 and then fed out by the cylinders 41, 43 with the edge of the folded down closing flap foremost. In a modification, Fig. 2 (not shown) the closing flaps are folded singly instead of in overlapped relationship. In a further modification, Fig. 3, (not shown), the blanks are supplied with their closing flaps ungummed and fed forwards with their bottom flaps overlying the closing flaps, the closing flaps being gummed after folding and gumming the bottom flaps; the closing flaps may be folded singly-or while the blanks are overlapped.