Packaging machine

Abstract

In a packaging machine, a pair of shutter members holds a tubular film therebetween and shake the tubular film. Articles on an upstream side of the shutter members within the tubular film therefore aggregate toward the side of the shutter members while the vibration of the shutter members causes the gaps between the packaged articles to be filled. Since the packaged articles aggregate by inertia due to the vibration, fragmentation thereof is less likely than in a case in which the packaged articles are compressed by direct contact. Merely by the movement of rollers on a waved surface of a shutter cam, the shutter members are shaken in accordance with the waved surface.

1 . A packaging machine that drops articles into a packaging material formed in a tubular shape and seals the packaging material making a bag with the articles packaged therein, said packaging machine comprising:
 a pair of sealing jaws that selectively hold the packaging material therebetween in a direction intersecting a conveyance direction of the packaging material and that selectively seal the packaging material; and   a pair of shutters that selectively hold the packaging material therebetween in a direction intersecting the conveyance direction and temporarily impeding advancement of the packaged articles, the shutters operating in synchronization with operation of the sealing jaws such that the shutters hold the packaging material prior to holding and sealing by the sealing jaws; wherein   upon the shutters holding the packaging material therebetween, the shutters advance a first distance in the conveyance direction, and further advance a second distance in the conveyance direction while shaking the packaging material in the state in which the packaging material is held therebetween.   
     
     
         2 . The packaging machine according to  claim 1 , further comprising
 a cam that contacts and guides a portion of the shutters such that the shutters move in accordance with a predetermined path defined by surface contours of the cam.   
     
     
         3 . The packaging machine according to  claim 2 , wherein
 the cam includes a flat surface section and an undulated surface section that contact the portion of the shutters thereby defining the predetermined path along the conveyance direction.   
     
     
         4 . The packaging machine according to  claim 1 , wherein
 said shutters are coil springs.   
     
     
         5 . The packaging machine according to  claim 2 , wherein
 the portions of the shutters that contact the cam are rollers.   
     
     
         6 . The packaging machine according to  claim 1 , wherein
 the sealing jaws seal the packaging material while the shutters are advancing the first distance.