| 摘要 |
934,941. Making envelopes. DAVID CARLAW (ENGINEERS) Ltd. April 24, 1961 [April 29, 1960], No. 15056/60. Class 94(2). An envelope making machine of the rotary type for folding and sealing down the bottom flaps of envelopes and folding down the sealing flaps is characterized in that the section of the machine arranged to fold down the gummed sealing flap comprises a suction roller 83, a co-operating roller 82 which engages the back of the envelope, the peripheral surface of the co-operating roller being formed to avoid contact with the gummed tip of the envelope, and a folding roller 93 which engages the front of the envelope, the suction being so timed that the sealing flap 30, during its passage between the suction and folding rollers is first nipped and then held against an undercut surface 92 of the suction roller 83, so that the gummed tip does not contact the folding roller or the envelope body. Envelopes, having folded-in side flaps 42, are fed in between rollers 60, 61 where adhesive is applied to the side flaps 42 by the roller 60; the adhesive being supplied from a bath 64 via rollers 65 to the roller 60. The envelope is then conveyed by means of a suction roller 62 to the first folding section, where the bottom flap 24 is pressed into adhesion with the side flaps 42 between rollers 70, 63 the suction port 63A engaging the front of the envelope and conveying it through the nip. The envelope is then conveyed past a guide 71, and between pairs of rollers 73 to the second gumming section where adhesive is applied to the sealing flap by the roller 80. It is then conveyed by the co-operating roller 82 of arcuate section to the final folding section, where the trailing sealing flap is seized by suction ports 90 along the crease 46, and as the envelope is urged through the nip between rollers 83, 93, suction ports 91 on the undercut surface 92 of roller 83 hold the gummed edge 30A of the sealing flap away from the body of the envelope. The envelope is impelled by ribs 53 to a drying conveyer beneath, (not shown). In an alternative arrangement where it is desired to apply adhesive to the side flaps and sealing flap using a single roller to prevent the upper co-operating rollers contacting the gummed edge of the sealing flap during conveyance through the machine, these rollers are in one case, cut away to form a sector, and in another case formed with a groove in the periphery. In both arrangements, the speeds of the different rollers are arranged with respect to position and relative size to produce a constant conveyance speed through the machine. |
