DISPOSITIVO A REGOLAZIONE ELETTRONICA PER IL TAGLIO PROGRESSIVO IN FOGLIETTI DI UNA BOBINA DI NASTRO DIMATERIALE IN FOGLIO ANCHE STAMPATO

摘要

A device for feeding sheets of wrapping material from a roll formed of wrapping material web to a packaging machine which discontinuously operates at consecutive cycles. The device includes a transversal cutter provided with cutter blades for cutting single sheets of wrapping material from the web which has a new leading edge after each cut, and at least one intermittent motion feeding group for feeding the web to the cutter. A first independent electric stepping motor drives the feeding group and is controlled by a programmable electronic control circuit which controls the stepping motor to drive the feeding group in accordance with a predetermined sequence of motions in synchronism with the cycles the packaging machine, including momentarily driving the feeding group backwards to withdraw and detach the leading edge of the web from the cutter blades.