Patent GB-709196-A (GB)
Title: Improvements in and relating to machines, for the manufacture of envelopes and flat bags
IPC: B31B70/00
Filed: 1950-05-03
Abstract: 709,196. Making envelopes or paper bags. PAHLITZSCH, W., [trading as PAHLITZSCH, B., [Firm of]]. May 3, 1950 [Oct. 1, 1948], No. 10854/50. Class 94 (2) In a machine for the alternative manufacture of envelopes and flat bags with internal slide seams, wherein a web of material fed from a roll is first printed upon and the side seams are cut therein and folded inwardly and gummed on their exposed upper surface, the forms of the bottom flap and closing flap being produced in severing the blanks in succession from the web, a change-over device is provided wherelby envelopes with gummed sealing flaps are carried around a drying device before delivery from the machine, or when bags with ungummed closing flaps are made, the bags are diverted to means for folding the flaps before delivery. A web 1 of paper or other material is fed from a roll 2 around guide rollers 5-7 and 24 to the first printing device 13, which prints upon the parts I / 13, Fig. 5, that will ultimately form the inside of the envelopes, and thence passes to a second device 22 and, if required, to a third similar device 23, where printing II/22 and III/23 is applied to the exteriors of the envelope blanks. From the printing devices the web passes around a guide roller 8 and tensioning roller 33, and between a pair of co-operating cutting-out rollers 26, 27, the latter roller being provided with cutting-sectors 28 for cutting out areas IV/28, Fig. 5, to provide folding seams at intervals on both edges of the web. Roller 27 is driven by a coaxial gear wheel 29 which is geared to the main machine shaft 50, while the counter roller 26, which is provided with two peripheral grooves to receive the cutters 28, is rotataibly supported on an arm 30 carried by a pivotal shaft 31. A toothed sector 32 secured on shaft 31 is engaged by an adjusting-pinion whereby the position of roller 26 can be adjusted for webs of different thickness. Waste cuttings are extracted through a pipe 37 connected to an exhausting-fan 36. From the cutting-rollers 26, 27 the web passes around a guide roller 39 to rollers 41, Fig. 2, which co-act with rubber-coated rollers 40 to produce preliminary seaming bends V/41, Fig. 5, for the folding seams in the longitudinal direction of the web. A subsequent tiltable guide roller 44 directs the web to a folder 42 and lower and upper guides 43, 43<SP>1</SP> which turn the seams down completely, as at VI/42, Fig. 5, the final folding and pressing being effected by rollers 45 cooperating with rollers 46 on spring-pulled bellcranks. The speed of the web to determine the length of the envelope blainks is controlled by an interchangeable gear wheel W removably 'mounted on an intermediate shaft 47 geared to the main shaft 50 and driving a feed-roller 51 through an intermediate gear wheel 53 mounted in a bearing in an adjustable member 54. The roller 51 also drives the printing-devices through associated gear trains. Adhesive VII/59 is applied to the inwardly folded seams while they are passing around the roller 51, the gumming roller being provided with segments 59 which cooperate with a gum-feeding roller 61 and are mounted on an eccentrically journalled cylinder so that the amount of gum taken up can be regulated. A transverse adjustment of the sectors 59 relative to their axis is also provided for operation on webs of various widths. The web is drawn forwardly between the roller 51 and a resiliently mounted roller 52, and passes beneath preliminary creasing-knives 66 extending axially along a roller 65 which co-operates with a lower roller 64 to produce a preliminary crease for the fold of the bottom flap of the envelope, as indicated at VIII/66, Fig. 5 ; at this stage the web is under tension by an ahead pair of feeding rollers 67, 68 rotating faster than the rearward feed rollers 51, 52. A fine adjustment of the position of the preliminary break is afforded by providing the roller 65 with a differential gear, and the relative positioning of the printing on the web and the fold for the bottom flap is examined in known manner by a testing-device comprising a lamp 69 associated with a photo-electric cell within am apertured cylinder 71. If a printed mark on the web does not register with the aperture in the cylinder an accelerating coupling is introduced temporarily until coincidence is restored. The web is next fed by the rollers 67, 68 to delivery rollers 74, 75 rotating at a speed which holds the web in tension while acted upon by a cutting-device mounted on a shaft 77 located between the aforesaid pairs of rollers. Cutting-device.-Alternatively operated cutting-devices are provided, comprising a form cutter 79 for operating on envelopes (as at IX/79-80, Fig. 5), or a cutting-off knife 80 for bags, there being :a stationary lower member 76 below the web at an adjustable inclination whereby a scissors-like cut related to the width of the web or its feeding-speed is produced. The form-cutting knife 79 consists of a relief-milled spiral-like surface resiliently held in a carrier on the shaft 77, there being pressure springs located between knife and carrier, and during the cutting action the speed of the knife 79 is accelerated to that of the web. For cutting off paper bags an adjustable upper knife 80 of known kind is mounted on the shaft 77. From the cutting-device the workpiece passes .between successive pairs of feed rollers, and before entering between one pair 85, 86 the bottom flap of the workpiece, lying in front in the feeding direction, is guided upwardly along its creasing line by a tiltable finger-like plate 87 co-operating with an upper guiding face 88, whereupon the crease in the bottom flap is engaged by a swinging folding-knife 89 and pressed between rollers 85, 86. The bottom flap is thus secured to the inwardly folded and previously adhesive-coated side seams (X/89, Fig. 5). Further pairs of rollers 90, 91 and 92, 93 advance the workpiece between a pair of rollers 94, 95 of which the upper roller 95 functions as a gumming roller by transferring gum from an adjustable gummer 97 to the closing flaps of envelopes fed thereto (XI/97, Fig. 5) or, when bags are being made and the gumming device is rendered inoperative, operating in conjunction with a deflecting device 142 to feed the bags to delivering and stacking apparatus. When the gumming device is operative automatic means is also operative in known manner to lower the roller 94 to avoid the application of gum thereto when there is .no envelope in the gumming position. An envelope leading the rollers 94, 95 with its closing flap opened and gummed passes between rollers 102, 103 on to endless transporting chains 119 operating' in synchronism with an intermittently rotating drum 106, Fig. 3 (not shown), carrying workpiece holders each of which receives an envelope from the chains 119. As shown in Fig. 4, the workpiece holders are supported on a series of hinge pins 112 which have their ends located within grooves N adjacent to the peripheries of a pair of disc-like frames 108 adjacent to and coaxial with a pair of inner wheels 106' forming part of the drum 106. Each workpiece holder comprises a rigid plate 110 secured in an articulated substantially U-shaped foot 109, with a resilent plate 111 riveted to the plate 110 at the end adjacent to the foot, the upwardly bent limb of one foot 109 being mounted on the same pivot pin 112 as the downwardly bent limb of the next but one foot 109, thereby providing an endless chain arrangement wherein the pins 112 are engaged and driven by a pinion 115, Fig. 2. With this arrangement adjacent workpiece holders are spaced apart at the receiving station so that an envelope can be inserted between them, the link chain being closed gradually and the adjacent holders pressed together during the circular travel. After carrying the envelopes around within the drying device the work holders gradually open (as shown in the lower part of Fig. 2), so that an envelope now lying freely on an upper plate 110 of a workpiece holder can be engaged by a dog on an endless chain 127 and pushed out, closing-flap foremost, to a cylinder 129 co-operating with a folding-knife cylinder 130. The closing flap is thus creased and then folded (XII/129-131, Fig. 5) by a rubber-coated roller 132 and finally guided to transporting worms 135 and deposited on assembly bays 138. A mechanical coupling K1, Fig. 2, is provided to enable the devices at the final folding station, and the drying apparatus, to continue functioning after the other parts of the machine have been halted. When the machine is required to produce bags with ungummed closing flaps, the deflecting bar 142, Fig. 2, is tilted upwardly so that the workpiece is diverted down betwsen rollers 94, 143 and 144-147 to flap-folding cylinders 129, 130 and delivered to the transporting worms 135.