| 摘要 |
893,863. Making envelopes. DOETSCH, W. May 5, 1958 [June 13, 1957], No. 14218/58. Class 94(2). A method of producing envelopes having gummed closure flaps wherein envelope blanks are stacked with the closure flap of each blank relatively staggered by-an amount equal to the width of the edge portion thereof to receive adhesive with the flaps of the blanks on each side, is characterized in that the exposed edge portions of the closure flaps are smoothed and heated by a plate, and adhesive applied to the exposed edge portions, each individual blank being removed and the flaps forming the back of the envelope being folded over and secured together to produce the finished envelope. As shown, envelope blanks 1 are successively separated from a pile by a suction roller 3 and guided towards a belt 5 by air nozzles 4. The blank is fed forward a distance corresponding to the depth of the closure flap to be gummed, on reaching the belt 5 by a roller 11 carried by a rocking lever; after feeding the rollers are lifted until the next blank arrives. Thus, the blanks are fed in staggered relationship between the belt 5 and a belt 14. A heated plate 15 heats and smooths the edge portions of the closing flaps. Adhesive is deposited on the flap edges by a roller 18. Discs 19 and rollers 20 feed the blanks under belts 22, the peripheral speeds of the discs 19 and belts 22 being higher than the belts 5 and 14 in order to reduce the overlap of the blanks. Cold air is supplied through a channel 30 to cool the heated closing flaps and dry the adhesive thereon. A conveyer band 34 co-operating with rollers 35 seize the blanks in turn and due to their speed further reduce their overlap, such that a trailing edge is uncovered. A suction roller 36 grips the closure flap trailing the leading blank and raises this flap such that fingers 39 on rollers 38 convey it to rollers 40, 41. The roller 40 has transverse scoring knives 42, 43 which score the blank to facilitate subsequent folding of the top and bottom closure flaps. Folding blades 48 are spaced apart a distance corresponding to the longitudinal fold lines of the side flaps. Air nozzles 51 raise the side flaps outside the blades 48, these being folded inwards by belts 53 passing around rollers 45, 46, and 47. A roller 58 deposits adhesive on the leading edges of the side flaps. The bottom flap is then folded by a folding roller 54 having suction openings 55 which grip the folded and glued blank behind the bottom fold line, the bottom flap being held raised by air jets 56 until the bottom flap folding line passes into the nip between the roller 54 and a shaft 57. The closure flap is then folded by a buckle folder having plates 64 and rollers 62, 63, and 66. Completed envelopes are delivered between a conveyer belt 71 and disc 72 against stops 74 on a delivery table 75. |
