Patent GB-426811-A (GB)
Title: Improvements in or relating to envelope making machines
IPC: B31B23/00
Filed: 1933-10-25
Abstract: 426,811. Making envelopes. BROOKS, H. C., 129, Fairlands Avenue, Thornton Heath, Surrey. Oct. 25, 1933, No. 29595. [Class 94 (ii)] Envelopes in continuous sequence are made by cutting from a continuous web of paper a series of blanks connected together by portions forming the top and bottom flaps of contiguous envelopes, gumming and folding the blanks longitudinally to form a series of connected flat tubes, gumming and drying the connecting portions, damping that part of each gummed connecting portion which forms the bottom flap of an envelope, or alternatively damping one end of the flat tube, and severing the connecting portions and folding over the end flaps so formed so that one flap adheres to the end of the tube and the other forms the sealing flap. A web 3 of paper is fed into the machine, being depressed by an oscillating frame 4<c>, and thence after moving past a guide bar 5 and rollers 6, 7 to shears 8, which cut out portions from the longitudinal edges of the web to form connected blanks, it has applied to it, on its under side, a longitudinal streak of gum a, Fig. 9, by a wheel 15 to form the longitudinal seam. The side flaps are folded over at 9 and pressed together, and the series of connected flat tubes is fed forwardly by a reciprocating device 27 to a gummer 34, 40 which gums the connecting portions of the flat tubes and wipes the same. The series is next led through a drier, which may be a separate unit for drying the gum on the connecting portions, and then to a further feed device 59 including a member which engages the envelope flaps and ensures corrent feeding to the guillotine 57 which severs the connecting strips of material. The series of connected tubes before severing, pass beneath a damping device 69 in which a moistened roller contacts with the gummed bottom-forming flap, or the lower part of the tubular body of the envelope. The feed device 59 may be assisted by a suction-feed device. From the guillotine the cut-off blanks are fed to a folding box where the bottom and closing flaps are folded over on to the body of the envelope and thence the formed envelopes are fed by belts to a collecting box. Web cutting.-The web, supported at 14, 14<a>, is cut at A and B (Fig. 9) by pairs of rotary shears 11, carried by transversely adjustable shafts 10, which coact with stationary shears 12. During the cutting operation the web is held upon the shears 12 by weighted pivoted clamping members 12a which are raised periodically by cams 12d. The pairs of shears 11, 12 are also adjustable for various lengths of envelopes. Seam gumming.-After the edges of the web have been cut to form a series of connected blanks, a longitudinal streak of gum a (Fig. 9) is applied by an adjustable wheel 15 to the under edge of the web, the wheel 15 rotating in the direction of the web and being held resiliently there against, or alternatively, it may be raised and lowered by cam action. Side-flap folding.-The side flaps are next folded over by adjustable hinged flaps 18, C (Fig. 9), one flap being provided with a presser bar which presses the seam, while a further presser bar 18<a> is reciprocated alternately with the web feed again to press the seam. Feeding.-The series of connected flat tubes, so formed, is fed forwardly by an adjustable device comprising a reciprocating convergent housing 27, 27<a> (Fig. 4a), in which are situated rollers 26, movable into or out of the housing. On being moved into the housing the paper is gripped and fed forwardly, while the rollers move idly when reciprocated in the reverse direction. Bottom and sealing - flap gumming.-The connecting portions of the paper tubes are gummed by a paddle 35, movable in a bath 34 fed from a reservoir 34<a>. The bath and reservoir are carried by pivoted links &c., moved by cam-action, to have a reciprocating motion on a lever 50 and a pivoting motion about a shaft 53 to effect contact of the paddle with the underside of the moving paper. After a strip of gum has been applied to the connecting portion, the bath is given a further upward movement and an edge 36 thereof, of rubber, felt, &c., spreads the same and wipes off any surplus which returns to the bath. The paddle is operated by the contact of an arm 38 attached thereto, with a plate 39, and an adjustable support 40, at about 45‹, behind the paper, takes the pressure thereof. Drying.-The connected flat tubes are then dried in a baffled chamber, supplied with hot air, the course being arranged helically around a set of freely mounted rollers 110 while, to return the material to the same line of travel, it is preferably led also around a second set of oppositely disposed rollers 110<a>. The first and last rollers are preferably synchronously driven to assist in the feed. Further feeding.-After drying, the series of connected flat envelope tubes, is fed farther by a reciprocating frame carrying a hinged plate 63 which contacts with the rear edge of each flat tube to feed, but rides freely on the return stroke. Rollers 65, carried by a spring-pressed rod 64 and engaging in a convergent housing 66, 67, operate to grip the paper during the feeding movement. Flap damping.-A roller 71, mounted on a reciprocating carriage 72, takes moisture from a trough 69 and, moving transversely of the paper on runways 71a, 74, damps that portion of the connecting piece which will be the bottom closing flap of the envelope. The series is then fed by rotary suction means 80 to a guillotine 57. Envelope severing.-The partially damped connecting portion is then severed by a vertically reciprocating guillotine 57, coacting with a stationary blade, which shapes the bottom and sealing flaps of contiguous envelopes. End-flap folding.-Adjacent the guillotine is a folding box, where the end flaps of the blanks are folded over by cam-operated articulated plates 91, 92, on to adjacent clamps 89, 90. A vertically reciprocating member lifts the folded blank, on release by the clamps, to a conveyer belt whereby it is fed to the grip of belts 99, 102, the end flaps being tucked therebetween by blades 100, 101 so to press the folded flaps and deliver the completed envelope to a collecting box.