A method of and machine for the manufacture of envelopes with gummed sealing flaps

摘要

709,007. Making envelopes. WINKLER, R., and DUNNEBIER, K. Nov. 17, 1950 [Nov. 18, 1949], No. 28173/50. Class 94(2) In a continuous method of manufacturing envelopes from a roll of paper the web is first printed upon, the envelope blanks out from it and given their final outline, and the shaped blanks stepped beneath one another between cooperating belt pairs so as to leave exposed the gum-receiving edges of the sealing flaps, these edges either having been gummed by the " profile " gumming process before entering between the belt pairs, or receiving gum by " stepgumming ". while between the belts, after which the blanks are passed along a gum-drying path into a stepped pile from which they are pulled off individually and then straightened and folded to complete the envelope. The machine is preferably arranged for the alternative employment of either profile gumming or step gumming as described in Specification 509,677. The successive steps of the method are illustrated diagrammatically in Fig. 1, wherein a paper web 1 run off from a roll 2 is printed on both sides in one or more colours at A and J and single blanks of the required shape, e.g. square or parallelogram, are cut therefrom by a knife 27, Fig. 3. In the example the knife 27 is in the form of a helix of wide pitch secured on a roller 25 which cooperates with an upper roller 26 provided with a circumferential insert 28 of hard steel. Rollers 25, 26 and their driving gears may be replaced by larger or smaller rollers and gears according to the size of blank required. Complete severance of the blanks from the web is effected by tearing- rollers 29, 30 rotating at higher speed than rollers 25, 26. At this stage the direction of the line of feed is changed angularly as shown at V, Fig. 1, so that the rollers 29, 30 deliver the blanks to further feeding rollers 31, 32, Fig. 5, in the new direction of feed. The change of direction is facilitated by forming both the rollers 29, 30 as segmental rollers by recesses in their peripheral surfaces and, of the pair 31, 32, making only 32 segmental. Each roller of the pair 31, 32 and of a further pair 33, 34 has on its shaft a short roller portion and a longer portion. Rollers 35, 36, each provided with annular knives mounted adjustably thereon at both ends, cut off the tips 3 of the side flaps (one tip only is shown severed at V, Fig. 1), and the blank is then taken by a suction roller 47, Fig. 4, and an adjacent series of suction discs 49 to devices for cutting notches 4 (shown at VI, Fig. 1) at the fold angles. These cutting devices, at both forward and rearward sides and at both ends of the series of discs 49, comprise rollers 51, 53 each with a stamping knife 55 co-operating with counter-rollers 52, 54 carried by arms 58 which are pivoted at the bottom ends of vertical arms 57 hanging from a transverse shaft 56 supported between the side plates of the machine and aibove the discs 49. Compressed springs 59 bearing on the arms 58 press the rollers 52, 54 towards the rollers 51, 53. The blanks, now in their final shape, are fed by suction discs 63 and guide rollers 65, 66 between pairs of conveying belts 67, 68 which reduce the speed of advance of the blanks, so that a stepped pile VII, Fig. 1, is built up. The rollers 65, 66 push each blank beneath the preceding one, so that the edges of the sruccessive sealing flaps are spaced at a distance corresponding to the width of sealing gum desired. The belts 67, 68 are superposed upon an arched guide plate 77 and the blanks pass beneath a step-gumming device (not shown) which applies gum to the free sealing-edge flaps. Pairs of guiding belts 78, 79, Fig. 4, then take the blanks along a drying path at a speed greater than that of belts 67, 68, so that the distance between the stepped gummed edges is increased sufficient to prevent them sticking together. The belts 78, 79 are driven independently and, while the belts 78 operate throughout the full extent of the belt conveyer, the belts 79 are succeeded by a succession of other top belts which take over their function. The gummed edges of the flaps are dried by warm air from a perforated conduit 112 located beneath the belts 78, 79, and the blanks are carried around between the belts and, at a return pulley 110, Fig. 8, pass beneath upper belts 108 and rollers 114, after which they are grasped between an intermittently driven conveying belt 115 and rollers 116. The belt 115 operates at a speed that increases considerably the stepped distance between the blanks, which are next fed by rapidly rotating rollers 117, 118 towards a pair of rollers 119, 120, Fig. 7, but before a blank reaches the latter pair its reentrant fold angles 4 are engaged and temporarily halted by front and' rear pairs of straightening-fingers 7, Fig. 8, which ensure their correct positioning. Passing between the rollers 119, 120, with the bottom flap leading, the blank is creased transversely along lines 51, 61, Fig. 1, by a pair of blades 121 on adjustable segments on the rollers 120, which cam be set to provide the creases of the top and bottom flaps of blanks of various sizes. The blank then passes beneath a. pair of adjustable side rails and between flap lifting devices while in the path between the pair of rollers 119, 120 and a pair 122, 123, and, on passing forward, the side flaps are folded inwardly (X of Fig. 1) by a transversely movable pair of laying-over devices 127. This action is assisted by a pair of arms 128 which swing transversely above the path of the blank and help to overcome the air resistance met with in folding the flaps inrwardly. The folds are pressed between rollers 124, 125 which feed the blank to further feed rollers and thence beneath an adhesive-applying device comprising a pair of vanes 134 arranged to apply adhesive k to the leading edges of the fblded side flaps, as at XI, Fig. 1. Feed. rollers 136, 137 (the latter being shaped to avoid contact with the adhesive on the flaps) then advance the blank to means for folding the bottom flap 5 along the folding line 51 to stick it to the adhesive stripes k and comprising a striker 140 which swings intermittently upwards to bend the bottom flap up prior to it passing between a pair of rollers 138, 139 which effect the fold, this action being assisted by an oscillating folding-knife 141. An oscillating guiding plate 142 in the path of the blank next operates to deflect it upwardly so that the still unfolded closing flap 6 is leading when a swing- ing knife 143 operates to fold it along the line 61 prior to it passing between pressing-rollers 138, 144. The envelope, now folded, and with the bottom fold trailing, slides down over a plate 145 between the periphery of a pair of conveying wheels 146 and a pair of guiding rails 147 spaced slightly from the wheels. Each wheel 146, which rotates a third of a revolution for each envelope fed thereto, carries three conveying cams 148 spaced around its periphery, the cams on the respective wheels 146 co-operating to form three pairs which, in turn, push the envelope around until it is engaged by a member which presses it to the rear of a pair of depositing discs 150 arranged as a double-threaded conveying worm. The envelopes are thus fed in succession to form a horizontal pile 151 and pass on to a conveyer belt 153. Specification 509,617 also is referred to.