Apparatus to replace a feed reel for feeding a covering film, to lay and cut a segment of film, and relative method

Method to automatically replace a feed reel for feeding a film with a replacement reel in an apparatus comprising a work plane, a store for the reels, laying means having first gripping means, cutting means having second gripping means and an unwinding assembly associated with each of said reels and comprising guide means, third gripping means and tensioning means, comprising the following steps:

• a step wherein said guide means pick up the end of the film from the feed reel and the tensioning means are driven in order to tension the segment of film between them and the second gripping means of the cutting means;
• a step wherein said third gripping means of the unwinding assembly are closed on said segment of film, the second gripping means of the cutting means are opened and the cutting means are distanced from the feed reel in order to free themselves from interference with said film;
• a step wherein the tensioning means are driven in order to recover the strip of film protruding from the guide means;
• a step wherein the store for the reels is driven in order to arrange said replacement reel in an operating position wherein said replacement reel has its end already in a suitable position for the start of the cycle;
• a step wherein said guide means are made to advance towards said cutting means, and the cutting means are brought near to said replacement reel until the relative second gripping means are located to grip on the film, after which said second gripping means are closed on the film;
• a step wherein said guide means release said film, said third gripping means of the unwinding assembly are opened and said tensioning means are activated, the cutting means are distanced from said replacement reel for a defined distance, said guide means retreat and said laying means and said cutting means are taken to the position to start a cycle to lay and cut said film.

Method to lay and cut a film fed from a reel in an apparatus comprising laying means having first gripping means, cutting means having second gripping means and an unwinding assembly associated with each of said reels and comprising guide means, third gripping means and tensioning means, comprising the steps of:

• a step wherein said laying means and said cutting means are displaced towards the reel to a zero position which determines the zeroing of the device that measures the length of the segment of film to be unwound;
• a step wherein the first gripping means of the laying means close in order to retain the end of said film;
• a step wherein the laying means are distanced from the reel in order to unwind the film until the portion between the cutting means and the laying means reaches the desired length;
• a step wherein said film is pressed against said work plane, the gripping means of the cutting means are closed on the film and cutting elements present on said cutting means are driven;
• a step wherein, once the film has-been cut, the laying means and the cutting means are distanced from the cut portion of film;
• a step wherein the gripping means of the laying means open and the laying means and the cutting means are positioned in proximity with said reel in order to allow the cut portion of film to be discharged.