| 摘要 |
1. A method of making continuous mailing or similar closed envelope forms with inserts consisting of uniting a lower continuous web (11, 111) and an upper continuous web (12, 112) by sealing along their longitudinal edges and along transverse bands overlapping corresponding weakening lines (11a, 12a) with a constant spacing E1 and intended for separating the continuous forms into single envelopes, this sealing being achieved in particular by pressure in a station having at its entrance at least one pair of entrainment rolls (13, 113) between which the two above mentioned webs are engaged, moved towards said entrance at the same speed V1 equal to the tangential speed of the entrainment rolls, along separate paths, characterised in that it consists of guiding and entraining at least one intermediate web (10, 110) with a width less than that of the lower web (11, 111) and the upper web (12, 112) and provided with weakening lines (10a) having a constant spacing E2 less than E1 towards the entrainment rolls (13, 113) at the entrance to the sealing station at a speed V2 less than V1 along respective paths, all this being done such that V2 /V1 = E2 /E1 , and of dividing said intermediate web (10, 110) along each of its weakening lines (10a) at the moment when they pass into a dividing station located upstream of the sealing station, and lastly, successively bringing each of the sections of the intermediate web (10, 110) in question thus formed into engagement with the entrainment rolls (13, 113) at the entrance of the sealing station between the lower web (11, 111) and the upper web (12, 112) mentioned above at an average speed substantially equal to V1 . |
