Heat-insulating container

Abstract

A heat-insulating food container includes an injection-molded container body having a bottom wall, a circumferential wall integrally connected to a periphery of the bottom wall and upwardly extending therefrom for defining an inner space and an upper open end, and vertical ribs vertically extending along the circumferential wall. The circumferential wall includes circumferential wall parts respectively having different diameters and arranged in such a manner as to form the circumferential wall with the diameter thereof decreasing in a stepwise manner as it advances downwardly, thereby forming corresponding stepped portions on an exterior surface and an interior surface thereof.

What is claimed is:  
     
         1 . A heat-insulating food container comprising an injection-molded container body having a bottom wall, a circumferential wall integrally coupled to a periphery of the bottom wall and upwardly extending therefrom for defining an inner space and an upper open end, and vertical ribs vertically extending along said circumferential wall, said circumferential wall including circumferential wall parts respectively having different diameters and arranged in series in such a manner as to form said circumferential wall with the diameter thereof decreasing in a stepwise manner as it advances downwardly, thereby forming corresponding stepped portions on an exterior surface and an interior surface thereof.  
     
     
         2 . A heat-insulating food container according to    claim 1    further comprising a downwardly-facing subsidiary rib extending along the circumferential wall in the circumferential direction thereof with a predetermined clearance with respect to said circumferential wall.  
     
     
         3 . A heat-insulating food container according to    claim 1    further comprising a plurality of downwardly-facing subsidiary rib s each respectively extending along the circumferential wall in the circumferential direction thereof at a different height with a predetermined clearance with respect to said circumferential wall.  
     
     
         4 . A heat-insulating food container comprising an injection-molded container body having a bottom wall, a circumferential wall integrally coupled to a periphery of the bottom wall and upwardly extending therefrom for defining an inner space and an upper open end, vertical ribs vertically extending along said circumferential wall, and at least one downwardly-facing subsidiary rib extending along said circumferential wall in a circumferential direction thereof to have a double layered annular portion with a predetermined clearance between the circumferential wall and said at least one downwardly-facing subsidiary rib, and each portion of said at least one downwardly-facing subsidiary rib between adjacent ones of said vertical ribs having laterally opposite edges being coupled to said adjacent ones of said vertical ribs.  
     
     
         5 . A heat-insulating food container comprising an injection-molded container body having a bottom wall, a circumferential wall integrally coupled to a periphery of the bottom wall and upwardly extending therefrom for defining an inner space and an upper open end, vertical ribs vertically extending along said circumferential wall, a flange formed around said upper open end of the container body, said container body having an annular stepped portion near the upper open end of the interior surface, said stepped portion serving as an indication line for indicating a suitable limit of hot water or the like poured into the container body, and a reinforcing means formed on said circumferential wall below said indication line and above a middle portion between the bottom wall and the open end for reinforcing said container body by providing a stepped portion on said circumferential wall.  
     
     
         6 . A heat-insulating food container according to    claim 5   , wherein said circumferential wall is formed in a stepwise manner to have a stepped portion serving as said reinforcing means.  
     
     
         7 . A heat-insulating food container according to    claim 5   , wherein said circumferential wall includes an upper circumferential wall part and a lower circumferential wall part, both of which are coupled together in a stepwise manner via an annular coupling part having a horizontal surface, a downwardly-facing subsidiary rib extending along a lower periphery of said upper circumferential wall part with a predetermined clearance with respect to the lower circumferential wall part, and with laterally opposite edges of each portion of said downwardly-facing subsidiary rib between adjacent ones of said vertical ribs being coupled to said adjacent ones of the vertical ribs, wherein said coupling part and said subsidiary strip together constitute said reinforcing means.  
     
     
         8 . A heat-insulating food container according to    claim 5   , wherein said reinforcing means positioned at a height of up to 50 to 70% from the bottom wall to the upper open end.  
     
     
         9 . A heat-insulating food container comprising an injection-molded container body having a bottom wall, a circumferential wall integrally coupled to a periphery of the bottom wall and upwardly extending therefrom for defining an inner space and an upper open end, and vertical ribs vertically extending along said circumferential wall, wherein the width (T) of a base part of each vertical rib and the thickness (t) of the circumferential wall are formed based upon the relationship of t≦T≦4t.  
     
     
         10 . A heat-insulating food container according to    claim 9   , wherein said injection-molded container body is made of a polypropylene resin having a melt index (MI) of 50 to 100, and has a wall thickness (t) of 0.2 mm to 0.6 mm.