Patent ID: 7022057

Claim:
A device for manufacturing packaging bags, comprising: a first transport roller to pull a first film from a first feed roller, whereby the first film has first marks at a constant first interval (a), a second transport roller independent of said first transport roller to pull a second film from a second feed roller, whereby the second film has second marks at a constant second interval (a′), a first servomotor that is connected with the first transport roller and with a first angle-of-rotation sensor, a second servomotor that is connected with the second transport roller and with a second angle-of-rotation sensor, a first sensor that is located upstream of and next to the first transport roller and scans the first marks, a second sensor that is located upstream of and next to the second transport roller and scans the second marks, a control device which is connected with the first servomotor, the second servomotor, the first sensor, the second sensor, the first angle-of-rotation sensor and the second angle-of-rotation sensor, and which controls the first servomotor and the second servomotor so that a first mark and a second mark, having passed said first and second transport roller, come to coincide and at least one first buffer for at least one of said first and second film, the at least one first buffer being located downstream of said first and second transport roller, and wherein the device comprises: a first idle mechanism and a second idle mechanism that together form a narrow feed gap for the two films, said first and second idle mechanisms being located downstream of the first and second transport roller respectively and wherein the at least one first buffer is located downstream of said first and second idle mechanism.