Patent GB-686309-A (GB)
Title: Improvements in or relating to machines for the manufacture of envelopes, paper bags and like articles
IPC: B31B70/00
Filed: 1949-07-05
Abstract: 686,309. Making envelopes, paper bags, &c. PAHLITZSCH,. W., (trading as BRUNO PAHLITZSCH). July 5, 1949 [May 14, 1949], No. 17789/49. Class 94(ii)  In a machine for the production of envelopes, flat paper bags and the like, wherein the folding and glueing of the side and bottom flaps of previously prepared blanks drawn from a stack takes place after the completion of any necessary printing, window-securing, or lining, the side flaps are folded whilst the blanks are being carried in the direction. of their greatetst length, with the two side flaps pointing forwardly and to the rear respectively, after which the bottom flap is folded with the aid of rollers which simultaneously initiate movement of the envelope in a direction at 90 degrees to its previous path. A blank, drawn by suction in known manner from the bottom of a stack 1, is fed through rollers associated with printing rollers 3, 4 for internal and external printing respectively and, after passing beneath a segment 5 which gums the open bottom flap B enters a folding pocket 6, Fig. 1, provided with a stop 7. Rollers 8, 9 then fold the side flap S<SP>1</SP> that is pointing rearwardly, and feed the blank into an adjacent pocket 10 provided with a stop 11, whereupon the forwardly pointing side flap S is folded, and the envelope is progressed towards a stop 13 associated with a folding knife 14 and rollers 15, 16 whereby the gummed bottom flap is folded and secured. At this stage the direction of movement of the envelope is changed by 90 degrees and it is fed forwardly between rollers 16, 30, Fig. 2 (not shown), in the direction of arrow b, with the folded bottom flap B towards the front and the loose closing flap C at the rear. A gumming device 17 next operates to gum the closing flap, and the single envelopes are carried to a stop 18 where they are gripped by the arms 19 of a forwarding device 20, their direction of movement is again changed by 90 degrees, and they are carried through a hot air channel, in the direction of arrow c, parallel with, but opposite to, their initial passage through the machine. The forwarding device 20 comprises a chain-conveyer with gripping members 19 fixed at intervals along it and holding the envelopes in an upright position with their gummed closing flap open and projecting sideways into the hot air channel. The return path of the drying circuit, indicated by arrow d, is substantially in the opposite direction to the forward path, and terminates at rollers 21, 22, Fig. 1, where the grippers are opened, the envelope being next carried to a stop 23 at which the closing flap is folded by a folding-knife 24 cooperating with rollers 25, 26. The direction of travel of the finished envelope is again changed by 90 degrees in the direction of arrow f leading to a delivery device 27. In the event that an envelope without a gummed sealing flap is required a removable stop 29, Fig. 2 (not shown) is inserted to block the path to the gumming device 17 and form the stop of a folder pocket associated with a pair of folding rollers 30, 31 which facilitate its diversion and exit in a downward direction to a delivering device 32.