Apparatus for making, handling, and filling pouches

Abstract

A conveyor for a pouch-filling machine has an endless track with a working stretch and a return stretch extending from a downstream end of the working stretch to an upstream end of the working stretch. A plurality of carriages each carrying at least one permanent magnet and a clamp ride on the track for movement through the stations on the working stretch and for movement from the downstream end of the working stretch along the return stretch back to the upstream end of the working stretch. An array of electromagnets on the track only along the working stretch and an electronic controller connected to the electromagnets together constitute a frequency-controlled linear direct drive that advances the carriages downstream through the working stretch while varying the travel speeds of at least half of the carriages in the working stretch. A mechanical or frequency-driven conveyor is provided in the return stretch.

We claim: 
     
         1 . In a machine having a production path provided with an upstream intake where individual pouches are made from a weldable film or individual premade pouches are loaded in and oriented with mouths of the pouches directed upward, a filling station downstream therefrom where contents are inserted into the open pouches through the upwardly open mouths of the pouches, and a sealing station downstream therefrom where the open mouths of the pouches are closed, a transport system comprising:
 an endless track having a working stretch extending along the path and a return stretch extending from a downstream end of the working stretch to an upstream end of the working stretch;   a plurality of carriages each carrying at least one permanent magnet and a clamp, the carriages riding on the track for movement through the stations on the working stretch and for movement from the downstream end of the working stretch along the return stretch back to the upstream end of the working stretch;   an array of electromagnets on the track only along the working stretch;   an electronic controller connected to the electromagnets to advance the carriages downstream through the working stretch while varying the travel speeds of at least half of the carriages in the working stretch so as to pucker and depucker pouches held in the clamps of the carriages; and   a mechanical or frequency-driven conveyor for displacing the carriages along the return stretch from the downstream end of the path to the upstream end of the path at a generally constant speed.   
     
     
         2 . The transport system defined in  claim 1  wherein the return stretch includes arcuate upstream and downstream turnaround regions at the upstream and downstream ends of the working stretch and a straight region extending generally parallel to the working stretch between the turnaround regions. 
     
     
         3 . The transport system defined in  claim 2  wherein the simple conveyor includes respective upstream and downstream wheels at the turnaround regions. 
     
     
         4 . The transport system defined in  claim 2  wherein each of the turnaround regions has a respective arcuate array of electromagnets connected to the controller, the mechanical conveyor extending only along the straight stretch. 
     
     
         5 . The transport system defined in  claim 1  wherein the simple conveyor displaces the carriages along the return stretch at a higher average speed than an average speed at which the carriages are moved by the controller in the working stretch 
     
     
         6 . The transport system defined in  claim 1  wherein the machine further has downstream of the intake station and upstream of the filling station:
 a puckering station where individual pouches made from a weldable film are opened for filling, and downstream therefrom 
 a depuckering station downstream where the upwardly directed mouth of the puckered pouch is opened.