Packaging container, packaging method and packing apparatus using same

Abstract

For providing a packaging container which permits easy separation of a film from the container, as well as a packaging method and a packing apparatus using the packaging container, the packaging container is constituted by a container for accommodating an article to be packaged, the container having a peripheral fitting edge and an upper opening, and a cover member formed by a film for covering the opening of the container, end portions of the film being converged to form a solid edge portion for fitting with the fitting edge of the container.

What is claimed is:  
     
         1 . A packaging container, comprising: 
 a container for accommodating an article to be packaged, the container having a peripheral fitting edge and an upper opening; and    a cover member formed by a film for covering the opening of the container, end portions of the film being converged to form a solid edge portion for fitting with the fitting edge of the container.    
     
     
         2 . A packaging container according to  claim 1 , wherein the fitting edge of the container is formed so as to project laterally outwards.  
     
     
         3 . A packaging container according to  claim 1 , wherein the opening of the container is formed in a shape which expands upwards of the container, and the edge of the container opening is formed as the fitting edge.  
     
     
         4 . A packaging container according to  claim 1 , wherein the film is a stretch film.  
     
     
         5 . A packaging method, comprising the steps of: 
 covering an opening of a container for accommodating an article to be packaged is covered with a film of a size which permits the film to overhang sideways from the opening of the container; and    converging the overhanging portions of the film overhanging sideways from the container opening to form a solid edge portion of a high rigidity for fitting with a fitting edge formed on the container side.    
     
     
         6 . A packaging method, comprising the steps of: 
 stretching a central portion of a film for covering an opening of a container which accommodates an article to be packaged outwards of the film so as to afford a film size overhanging sideways from the opening of the container;    covering the opening of the container with the stretched film; and    converging overhanging portions of the film overhanging from the container opening to form a solid edge portion for fitting with a fitting edge formed on the container side, the solid edge portion having a higher rigidity than the rigidity of the film.    
     
     
         7 . A packaging method according to  claim 6 , wherein the central portion of the film is stretched outwards of the film and in directions perpendicular to sides of the container.  
     
     
         8 . A packaging method according to  claim 6  or  7 , wherein a central portion of the film is allowed to stretch outwards of the film by straight movement of film grippers that grasps the film.  
     
     
         9 . A packaging method according to  claim 6  or  7 , wherein a central portion of the film is allowed to stretch outwards of the film by rotating movement of film grippers that grasps the film.  
     
     
         10 . A packaging method according to  claim 6  or  7 , wherein a central portion of the film is allowed to stretch outwards of the film by the steps including: 
 grasping the film by film grippers;  
 sinking a plurality of fingers that is capable of spreading; and  
 spreading the fingers so as to stretch outwards of the film.  
 
     
     
         11 . A packaging method according to claims  5 ,  6 ,  7 ,  8 ,  9  or  10 , wherein end portions of the film are allowed to converge by heating to form the solid edge portion.  
     
     
         12 . A packing apparatus, comprising: 
 a controller for controlling each portion so as to allow execution of certain operation;    a film grippers, controlled by the controller, for grasping a film afforded a film size overhanging sideways from the opening of the container which accommodates an article to be packaged, the film grippers positioning the film above the container opening;    a mechanism, controlled by the controller, for moving the film grasped by the film grippers to the container opening relatively so as to cover the container opening with the film; and    a mechanism, controlled by the controller, for converging the overhanging portions of the film overhanging sideways from the container opening to form a solid edge portion of a high rigidity for fitting with a fitting edge formed on the container side.    
     
     
         13 . A packaging apparatus according to claims  12 , wherein the film grippers grasp four corners of the film and stretch the film outwards of the film.  
     
     
         14 . A packaging apparatus according to claims  13 , further comprising a film pulling mechanism, controlled by the controller, that grasps each sides between the corners of the film and stretch the film outwards of the film.  
     
     
         15 . A packaging apparatus according to claims  12 , further comprising a plurality of fingers, controlled by the controller, that is capable of spreading and spread so as to stretch outwards of the film.  
     
     
         16 . A packaging apparatus according to claims  12 ,  13 ,  14  or  15 , wherein the mechanism for converging the film converges by heating the edge of the film to form the solid edge portion.  
     
     
         17 . A packaging apparatus according to claims  12 ,  13 ,  14 ,  15  or  16 , further comprising a film unit for cutting the film so as to afford a film size overhanging sideways from the opening of the container.