Method for recharging a bundling machine using a plastic film and bundling machine carrying out said method

Abstract

Methods for recharging a machine which is used to pack groups of products with the aid of a plastic film wherein the film of a distributor reel is unwound, the film of a full reel is subsequently engaged into an injection device in such a way that said reel becomes a distributor reel in turn, then the empty distributor reel is replaced with a new full reel. While a reel is being distributed, the full reel is placed in the machine and the free end of the film connected to the full reel is maintained in a waiting position; when it is detected that the end of the film of the distributor reel has reached a predetermined position, the advance of the film of said reel is halted and the free end of the film connected to the full reel is driven in such a way that it becomes a distributor reel; while the full reel is being distributed, the empty distributor reel is replaced by a new full reel and the free end of the beginning of the film connected to said new reel is maintained, whereupon the previously mentioned cycle is resumed with a new reel when the final extremity of the film of the full reel which is being distributed reaches a predetermined position in the machine.

1 . An apparatus that packages products with a plastic film, the apparatus comprising: 
 means for storing a first spool;    injection and cutting means, which is fed with film from the first spool;    means for storing a second spool; and    two arrangements for alternatively distributing the film from one spool and from the other to the injection and cutting means,    wherein the two arrangements comprise drive and hold means for detecting that the end of the film on the first spool has reached a predetermined position in the injection and cutting means, for stopping an advance of the film from the first spool into the injection and cutting means so as to leave a remaining part of the film from the first spool, wherein the remaining part of film from the first spool includes the end of the film from the first spool, and for causing the free end of the film connected to the second spool to be drawn into said injection and cutting means, so that said second spool becomes a distributor, and such that the film from the first spool is not fastened to the film from the second spool, and while said second spool is in the process of distribution, said drive and hold means replaces the first spool that was emptied with a new full spool and fuses a leading end of film from the new full spool to a trailing end of the remaining part of the film from the first spool and maintains, at the entrance of the injection and cutting means, a free end of the remaining part of film connected to said new full spool, and utilizes film from the new full spool when the end of the film from the second spool, in the process of distribution, reaches a predetermined position in the injection and cutting means.    
   
   
       2 . The apparatus according to  claim 1 , wherein the arrangements are identical.  
   
   
       3 . The apparatus according to  claim 1 , wherein the injection and cutting means are comprised of a single injection and cutting device having at its entrance injection rollers for injection of the film, and the drive and hold means are comprised of a first and second drive and hold devices different from each other arranged upstream from the injection rollers, wherein if the first drive and hold device stops the advance of the film from the first spool, the first drive and hold means is configured to reverse the movement of the film in said first drive and hold means so as to release the free starting end of the first film, it is held with the first drive and hold device, and the free end of the second film is then drawn between the injection rollers with the second drive and hold device.  
   
   
       4 . The apparatus according to  claim 3 , wherein each of the first and second drive and hold devices is comprised of two holding rollers for maintaining contact with each other, between which a film is placed, and the rollers either drive the film toward the injection rollers to allow it to be picked up by them, or hold the film immobilized, or allow the film to pay out when it should be driven by the injection rollers.  
   
   
       5 . The apparatus according to  claim 4 , further comprising: 
 motorized units, wherein the holding rollers are connected to the motorized units, and the motorized units are designed to be turned on to drive the film toward the injection rollers in order for it to be picked up by them, and to be stopped to hold the film immobilized.    
   
   
       6 . The apparatus according to  claim 5 , wherein the motorized units are designed to be turned on when the film should be driven by the injection rollers, so that the film is driven by the holding rollers at the same speed as the injection rollers.  
   
   
       7 . The apparatus according to  claim 5 , wherein the holding rollers are self-disengaging with respect to the motorized units, and are disengaged when the film is driven by the injection rollers, so that the film travels freely between the holding rollers.  
   
   
       8 . The apparatus according to  claim 5 , wherein at least one of the holding rollers of each drive and hold device is provided with a flat surface parallel to the axis of rotation of the roller, and the motorized units are designed to place the flat surface facing the other roller of each of the drive and hold devices when the film should be driven by the injection rollers, so that the film runs freely in the gap that then appears between the two rollers, and the injection rollers and the holding rollers of each of the drive and hold devices are arranged so that the length of the portion of film that could be taken between the injection rollers and the holding rollers is less than the perimeter of the cylindrical portion of each roller provided with a flat surface.  
   
   
       9 . The apparatus according to  claim 1 , wherein the injection and cutting means are comprised of two different injection and cutting devices each of which receives the film from a spool, and each of which has, at its entrance, drive rollers; for driving the film, and the drive and hold means are comprised of the drive rollers situated at the entrance of the injection and cutting means, and the drive and hold means is designed so that the advance of the film from a spool in process of distribution into an injection and cutting device among the two different injection and cutting devices is stopped by stopping the rotation of its drive rollers at the entrance, and the starting end on standby in the other injection and cutting device is driven by placing its drive rollers in rotation.  
   
   
       10 . The apparatus according to  claim 9 , further comprising: 
 means for accompanying the film in process of distribution leaving from one or the other of the two different injection and cutting devices toward a packaging zone of the apparatus where the packaging of the products is performed.    
   
   
       11 . The apparatus according to  claim 10 , wherein the means for accompanying the film in process of distribution comprises at least a transport belt placed, in the direction of advance of the film, downstream from the different injection and cutting devices, each of which include cutting units.  
   
   
       12 . The apparatus according to  claim 11 , wherein the transport belt is placed in such a way as to accompany the film up to the packaging zone.  
   
   
       13 . The apparatus according to  claim 11 , wherein the transport belt is placed in such a way as to accompany the film up to a movable guide device, in order to grip the film at its exit from the transport belt and run it along an appropriate path to package the group of products.