Patent GB-715644-A (GB)
Title: Improvements in or relating to envelope manufacture
IPC: B31B19/00
Filed: 1952-02-19
Abstract: 715,644. Making envelopes. ROLLINSON, E. W. (United States Envelope Co.). Feb. 19, 1952. No. 4361/52. Class 94 (2) Envelope making apparatus comprises means for folding over the side flaps of successive blanks advancing in spaced relation, means for overtaking each so folded blank by the next following so folded blank to an extent such that edges of the folded-over side flaps of the one are slightly overlapped by the seal flap edge of the other, and means for producing at each such zone of overlap a single adhesive imprint common to both blanks thereof, whereby the seal flap on one is gummed fully to its edge, and the other receives adhesive for subsequent sticking of its bottom flap to its side flaps. As shown successive partly folded blanks B are fed forward by high speed rolls 10, 11, and 16, 17, the rolls 16, 17, consisting of pairs of narrow upper and lower rolls which engage only the outside edge of each blank. Spaced pairs of narrow upper and lower rolls 24, 25, continue the blank's movement at approximately half its former speed, the upper rolls 16 being cut away as at 23 to discontinue the high speed propulsion of a blank when it has come under the influence of the rolls 24, 25, and the upper rolls 24 being cut away at 33 to effect a smooth transition. In this way the leading edges 34. of each following blanks unfolded side flaps are slightly overlapped by the edges 35 of the preceeding blank's trailing seal flap as shown at 36. To avoid collision between the portions 37 and 38 of the blanks and to ensure that the latter passes under the former, the reduced portion 12 of the roll 11 is provided with a leaf spring 39 which lifts the portion 37 as it is being overtaken by the portion 38. Collision between the edges 34 and 35 is avoided by means of a curved spur 41 rotating with the shaft 18, which lifts the seal flap apex 37. The extended bottom and seal flaps are supported by a pair of horizontal longitudinally extending rails, Fig. 2 (not shown), and the side flaps are held down by pairs of plates 44 and 45 The blanks are kept in their path of travel by a series of guides 49. which co-operate with a pair of rails 48. Pairs of upper and lower rolls 53, 54, feed the overlapping blanks to the gumming station 52 at the reduced speed. where each successive zone of overlap 36 receives a single imprint of glue providing a portion 60 for the preceding blank's sealing flap and a portion 61 on the following blank's side flaps. The glue is applied by a contoured roller 62 on a shaft 64 which oo-operates with a roller 63 and a glue roll 71, the blanks travelling through the gumming station at the reduced speed. Pairs of narrow upper and lower rolls 75, 76, transfer the blanks to a table 73 where they are seized by high speed rolls comprising a lower roller 83 and a pair of upper spaced narrow rolls 34. The rollers 75 are cut away at 82 and the rollers 84 are cut away except for a portion of approximately 90 degrees extent, to enable the speeding up of the blanks to take place smoothly. The lower roller 83 rotates on a hollow stationary shaft 85 A transverse scoring blade 91 is carried between the rolls 84 and co-operates with a yieldable insert 92 on the roller 83 to give each blank the score line 93 defining the fold of the bottom flap. Just behind the score line 93 the blank is suctionally gripped by the roller 83 which is provid.ed with a slit 94 communicating periodically. through a port 95, with the interior of shaft 85. which is connected to a source of suction. In order to adjust the timing of the release and seizure of successive blanks by rollers 83 the shaft 85 carries a worm wheel 96 which meshes with a worm 97 on a vertical shaft provided with a handle, the shaft being locked in position by a locking screw 100. The bottom flap 3 of each blank arriving at the pressing roller 104 is deflected upwardly by a projection 101 on roller 83, and is prevented, by a guard 112 from making contact with the upper portion of roller 104. To keep the seal flap glue 60 from making contact with the shaft 86 a guard 103 is provided. Each blank's downward movement by roller 83 carries it, score-line foremost. between the rollers 83 and 104 whereupon the suctional grip of roller 83 is released, and the score line is converted into a fold for the bottom of the envelope. The contact surface of the roller 104 corresponds to and registers with the bottom flap 3 which is thereby pressed against the glue imprints 61 to complete each envelope's adhesive seam. A projection 110 on the roller 104 prevents the seal flap with its wet glue 60 from swinging toward the roller 104. At each end of the pressing roller narrow rollers 120 are provided and a member 114 guides each envelope between the roller portions 120 and a pair of discs 115, a travelling belt 118 delivering the envelopes to a drying chain (not shown). Specification 509,617 is referred to.