Patent GB-676631-A (GB)
Title: Improvements in or relating to the manufacture of folded envelopes from blanks
IPC: B31B19/00
Filed: 1949-05-17
Abstract: 676,631. Making envelopes. BAYLES, S., and TUCKER, J. S. May 17, 1950 [May 17, 1949], No. 13096/49. Class 94(ii) In a machine for making laterally folded blanks into envelopes, side marginal portions of one part of each blank are turned downwardly for movement along slots or gaps formed between the opposite edges of a feed table for the blank and forming elements adjacent thereto, each forming- element having a curved surface which engages a marginal portion of the blank as it traverses the slot or gap and folds it under so that it can be secured to the other part of the blank to form the envelope. Envelope blanks entering the machine in the direction of the arrow A, Fig. 1, are received between a pair of knurled rollers 17 mounted one above the other on shafts 16, the respective shafts being mounted between pairs of end bearings which are adjustable vertically within slots in the side plates 1, 2 by means of adjusting screws 23 acting on compression springs. The parts of the rollers which engage the blanks project within slotted portions 25 of the adjacent edges of the parts 14 of a feed table formed by two such parts spaced longitudinally. The blanks are advanced to a pair of creasing rollers 26, 27 which are adjustable along a shaft 28 and co-operate with a pair of rollers 30, 31, Fig. 41, mounted below them, the upper pair being provided with annular grooves 36, 37 respectively to receive peripheral lips 38, 39 on the lower pair.- Adjustment of the distance between the lips is obtained by sliding the rollers 30, 31 upon guide rods 34, 35 which are mounted in an intermediate collar 33 on a shaft 32 and extend into holes bored in the rollers. These rollers form a folding-crease or score along the lines b at which the marginal portions c of the blanks are subsequently folded; the bearing supports for the shafts of these and other rollers between which the blank is fed are similar to those of the shafts 16. From the creasing- rollers the blank passes between a pair of rollers of which the upper roller is a composite one provided with inwardly bevelled end flanges 45, 46 mounted on' cylinders 43, 44 that can be adjusted axially along a supporting shaft 41, either inwardly or outwardly relative to an intermediate cylinder 40 mounted on the shaft. The flanges 45, 46 act to turn the side flaps c of the blank downwardly through an angle of 90 degrees about the folding creases b and guide them into gaps or slots 52, 53 provided between the outside edges of the folding table 14 and forming-elements 54, 55. Forming- element 54 is shown in perspective in Fig. 7, and comprises a part substantially rectangular in cross-section adjacent to the roller flange 45, and curving outwardly at 56 towards its rear portion which has a stepped enlargement 57. The successive positions of the leading-edge of a blank are indicated in broken lines at d, e, and f, which show the side flap: - (1) at rightangles to the body of the blank; (2) at the commencement of the turn at surface 56; and (3) completely turned under the upper part of the blank. The blank is provided with gummed stripes g along the side flaps c prior to entering the apparatus, and the gummed portion is turned towards the underside of the table by the folding device. To avoid the gum sticking to the table , the edges of the latter are cut away at 58, leaving only a guiding finger 59 to maintain the fold at the marginal edge while the blank enters between a pressing roller 60 and a co-operating lower roller. Further pressing is effected by two pairs of rollers 63, 64.