Packaging machine for block bottom bags

Abstract

A rotary packaging machine ( 10 ) that receives tubular bag material and moves the tubular bag material in a direction ( 11 ). Product is delivered to the interior of the tubular bag material with the bag material then being sealed and cut to form bags of the product. The machine ( 10 ) has a jaw carriage ( 14 ) that is reciprocated while the jaws ( 29 ) are rotated.

1 . A packaging machine to form bags, containing a product, from tubular bag material into which the product is delivered, the tubular bag material being moved relative to the machine in a predetermined direction, said machine including:
 a base;   a jaw carriage supported on the base for reciprocating movement generally parallel to said direction;   a pair of jaws mounted on the carriage and moved in unison to engage the tubular bag material to transversely seal the tubular bag material to form bags;   a pair of generally parallel shafts, each shaft being operatively associated with a respective one of the jaws to drive the jaws, the shafts having longitudinally axes that extend generally transverse of said direction;   a jaw drive assembly operatively associated with the shafts to drive the shafts through repeated revolutions in opposite angular directions so that the jaws engage the tubular bag material;   a carriage drive assembly operatively associated with the carriage to cause said reciprocating movement; and   a controller operatively associated with the drive assemblies to coordinate the assemblies.   
     
     
         2 . The machine of  claim 1 , further including a pair of cooperating stripper bars, each stripper bar being operatively associated with a respective one of the jaws to move therewith to strip the tubular bag material. 
     
     
         3 . The machine of  claim 1 , further including a pair of tube closer bars, each of the closer bars being operatively associated with a respective one of the jaws to engage the tubular bag material to close the tubular bag material. 
     
     
         4 . The machine of  claim 1 , wherein said jaw drive assembly is mounted on said carriage. 
     
     
         5 . The machine of  claim 1 , wherein said carriage drive assembly is a linear motor at least partly mounted on said base and at least partly mounted on said carriage, so that said carriage when reciprocated moves along a generally linear path. 
     
     
         6 . The machine of  claim 1 , wherein each jaw is attached to its respective shaft by a jaw support. 
     
     
         7 . The machine of  claim 6 , wherein each jaw support includes at least one arm extending generally radially relative to its respective shaft. 
     
     
         8 . The machine of  claim 6 , wherein each jaw is fixed relative to its respective support. 
     
     
         9 . The machine of  claim 6 , wherein each jaw is attached to its respective shaft by a support, with each jaw being mounted on its respective support for angular movement relative thereto about an axis generally transverse of said direction. 
     
     
         10 . The machine of  claim 9 , wherein the jaws are attached by guides so that the jaws move in unison in opposite directions while facing each other. 
     
     
         11 . The machine of  claim 1 , wherein the jaws are mounted on their respective supports for movement relative thereto in a radial direction. 
     
     
         12 . The machine of  claim 1 , wherein said carriage includes a pair of generally parallel walls between which said shafts extend, and an end wall adjacent said base and including portion of said linear motor.