Packaging machine and method

Abstract

A machine for packaging articles includes: a feed mechanism for feeding a film to a packaging station, where the film is used to wrap the articles, a conveying line for conveying the articles to the packaging station along a conveying path extending from a pickup zone, where the articles are picked up, to a release zone, where the articles are released, the conveying line including a plurality of pushing and transfer mechanisms configured to pick up the articles at the pickup zone and be driven independently. A control and drive unit drives each pushing and transfer mechanism in a portion of the conveying path according to a law of motion which is variable as a function of signals, for releasing the articles at the release zone in coordination with the packaging station, at a distance from each other and at a controlled speed.

1 . A machine for packaging articles comprising:
 feed means for feeding a film to a packaging station, where the film is used to wrap the articles,   a conveying line for conveying the articles to the packaging station along a conveying path extending from a pickup zone, where the articles are picked up, to a release zone, where the articles are released, the conveying line comprising at least two pushing and transfer means, being first means for pushing and transferring the articles and second means for pushing and transferring the articles, respectively, the first and second pushing and transfer means being configured to pick up the articles in turn at the pickup zone and being able to be driven independently, the machine comprising a control and drive unit connected:   to the film feed means for receiving a signal representing a speed of film feed,   to the pushing and transfer means for receiving a signal representing the positions in turn adopted by the pushing and transfer means,   and to the packaging station for receiving a phase signal,   the control and drive unit being programmed to drive each of the pushing and transfer means in at least one portion of the conveying path according to a law of motion which is variable as a function of the signals, for releasing the articles at the release zone in coordination with the packaging station, at a distance from each other and at a controlled speed, wherein:   each of the pushing and transfer means comprises a unit movable along a rail forming a closed loop to transfer the articles from the pickup zone to the release zone along the conveying path, the movable unit of each of the pushing and transfer means and the rail constituting, in combination, a linear motor able to be activated to allow movement of the unit along the conveying path; said rail being a single rail with which are associated the units of the pushing and transfer means.   
     
     
         2 . The machine according to  claim 1 , wherein the conveying line further comprises third means for pushing and transferring the articles, the first, second and third pushing and transfer means being able to be driven independently and configured to pick up the articles in turn at the pickup zone. 
     
     
         3 . The machine according to  claim 1 , wherein the conveying line is provided with a supporting surface for supporting the articles moving along the conveying path. 
     
     
         4 . The machine according to  claim 1 , wherein the supporting surface has an opening made in it which extends along the conveying path and which opening is engaged by the pushing and transfer means when they come into abutment with the articles along the conveying path to push them along the supporting surface. 
     
     
         5 . The machine according to  claim 1 , wherein the control and drive unit is programmed to drive each of the pushing and transfer means in at least one part of the portion of the conveying path according to an accelerated law of motion. 
     
     
         6 . The machine according to  claim 1 , comprising movement means, located upstream of the conveying line, for moving the articles and feeding them to the conveying line, and connected to the control and drive unit to be driven as a function of the film feed speed in such a way as to space out the articles moved by them. 
     
     
         7 . The machine according to  claim 1 , comprising detecting means for the articles, designed to allow an incoming article to be detected as it reaches the conveying line, and connected to the control and drive unit to generate a signal indicating the arrival of an article. 
     
     
         8 . A method for packaging articles comprising the steps of:
 feeding a film used for wrapping the articles at a packaging station;   picking up the articles at a pickup zone and transferring the articles to a packaging station along a conveying path extending from a pickup zone to a release zone, this picking up step being performed in turn by at least two pushing and transfer means, being first pushing and transfer means and second pushing and transfer means;   wherein the method comprises the following steps:   adjusting the relative speed of article transfer of the pushing and transfer means along at least one portion of the conveying path as a function of a signal representing the feeding speed of film, of a signal representing the positions adopted in turn by the pushing and transfer means and of a phase signal of the packaging station, for releasing the articles at the release zone in coordination with the packaging station, at a distance from each other and at a controlled speed.   
     
     
         9 . The method according to  claim 8 , wherein the speed adjusting step comprises setting the speed of the pushing and transfer means which are located along the conveying path in the proximity and downstream of the pickup zone to a value higher than the value of the speed of the pushing and transfer means which are located along the conveying path downstream of the pushing and transfer means, so as to reduce the relative distance between the pushing and transfer means along the portion of the conveying path. 
     
     
         10 . The method according to  claim 8 , further comprising the step of:
 detecting an incoming article when it reaches the pickup zone.   
     
     
         11 . The method according to  claim 10 , comprising, in order, the steps of:
 stopping the pushing and transfer means in standby position at the pickup zone;   setting the pushing and transfer means in motion to perform the pickup step as a function of detection of an incoming article when it reaches the pickup zone.   
     
     
         12 . The method according to  claim 8 , wherein the pickup step is performed by the first pushing and transfer means, by the second and by the third pushing and transfer means in turn.