Tamper resistant container

Abstract

A vacuum formed, tamper resistant container resists deformation of the sides thereof that might otherwise permit access to contents of the container without removal of the lid. Downward protruding lid features reinforce the wall of the container base, and buttress features included in the rim of the base extend from a base flange diagonally downward and inward to the inner rim of a recessed shelf, thereby resisting downward rotation of the wall beneath the lid protruding features. In embodiments, attachment tabs surrounded by frangible boundaries are incorporated in the lid and attached to the base by living hinges, such that removal of the lid requires breaking of the frangible boundaries and detachment of the lid from the attachment tabs. Pucker elements associated with the attachment tabs can cause the attachment tabs to pivot away from the lid when the attachment tabs are detached from the lid.

We claim: 
     
         1 . A tamper resistant container, comprising:
 a base having a substantially horizontal bottom joined at a perimeter thereof to a lower edge of at least one substantially vertical base wall, an upper edge of the at least one base wall terminating in a substantially horizontal shelf extending outward from the upper edge of the at least one base wall and terminating in a substantially vertical, upwardly extending rim wall, said rim wall terminating in an outwardly extending, substantially horizontal base flange;   a lid surrounded by a substantially horizontal lid flange, the lid comprising a plurality of protruding lid features proximate and surrounded by the lid flange and extending downward from the lid flange, wherein the lid can be installed onto the base such that the lid flange rests on the base flange, and the protruding lid features extend downward along the rim wall of the base toward the shelf of the base; and   at least one buttress feature, each of the buttress features being a horizontal indentation in the shelf and rim wall of the base, the indentation being bounded by an upper buttress wall that extends obliquely from the top of the rim wall to the top of the base wall.   
     
     
         2 . The container of  claim 1 , wherein upon first installation of the lid on the base, the protruding lid features form a substantially airtight seal between the lid and the base. 
     
     
         3 . The container of  claim 1 , wherein the base comprises a plurality of sides, and wherein each of the sides of the base includes at least one of the buttress features. 
     
     
         4 . The container of  claim 1 , wherein the lid is attached to a hinge edge of the base flange by at least one living hinge. 
     
     
         5 . The container of  claim 4 , wherein the lid attachment to the base is frangible. 
     
     
         6 . The container of  claim 1 , further comprising at least one attachment tab attached by a living hinge to a hinge edge of the base flange, all of the attachment tabs being attached to the same hinge edge of the base flange, all of the attachment tabs being incorporated into the lid flange and being substantially co-planar with the lid flange, the attachment tabs being bounded by frangible tab boundaries that permit the attachment tabs to be broken free of the lid, whereupon the lid is freed from the base. 
     
     
         7 . The container of  claim 6 , wherein each of the attachment tabs is coordinate with a corresponding pucker element that is configured to apply a lifting force to the attachment tab, such that when the attachment tabs are broken free from the lid and the lid is subsequently re-installed on the base, the attachment tabs are caused by the pucker elements to extend upward out of the plane of the lid flange. 
     
     
         8 . The container of  claim 6 , further comprising a lid pull tab extending from the lid flange and a base pull tab extending from the base flange, the lid and base pull tabs being proximate each other but not fully overlapping when the lid is installed on the base, so that the lid and base pull tabs can be separately grasped and pulled apart from each other, thereby breaking the frangible tab boundaries of the attachment tabs and freeing the lid from the base. 
     
     
         9 . The container of  claim 6 , wherein gaps between the protruding lid features are provided in the regions of the attachment tabs so that the protruding lid features do not overlap the attachment tabs, and so that upon reattachment of the lid to the base, the container is ventilated due to openings in the lid resulting from the breaking free of the attachment tabs from the lid. 
     
     
         10 . The container of  claim 6 , wherein in the regions of the attachment tabs the protruding lid features are located inward of the attachment tabs, so that the protruding lid features do not overlap the attachment tabs, and so that upon reattachment of the lid to the base, the container is not ventilated due to openings in the lid resulting from the breaking free of the attachment tabs from the lid. 
     
     
         11 . The container of  claim 10 , wherein the protruding lid features are located inward from the attachment tabs and are substantially parallel with the hinge edge of the base flange. 
     
     
         12 . The container of  claim 10 , wherein the protruding lid features are proximate the hinge edge of the base flange in regions between the attachment tabs, and are offset inward from the hinge edge of the base flange in regions proximate the attachment tabs, such that the protruding lid features do not overlap the attachment tabs. 
     
     
         13 . The container of  claim 1 , wherein the lid flange is narrower than the base flange, such that the base flange extends horizontally outward further than the lid flange when the lid is installed on the base. 
     
     
         14 . A tamper evident container, comprising:
 a base having a substantially horizontal bottom joined at a perimeter thereof to a lower edge of at least one substantially vertical base wall, the base comprising a substantially horizontal base flange extending outwardly from an upper rim of the base;   a lid that can be installed onto the base such that a seal is formed between the lid and the base, the lid being surrounded by a lid flange; and   at least one attachment tab attached by a living hinge to a living hinge side of an upper edge of the base, all of the attachment tabs being attached to the same living hinge side of the upper edge of the base, all of the attachment tabs being incorporated into and substantially co-planar with the lid flange, and being bounded by frangible tab boundaries that permit the attachment tabs to be broken free of the lid, thereby freeing the lid from the base;   each of the attachment tabs being coordinate with a corresponding pucker element that is configured to apply a lifting force to the attachment tab, such that when the attachment tabs are broken free from the lid and the lid is subsequently re-installed on the base, the attachment tabs are caused by the pucker elements to extend upward away from the lid flange.   
     
     
         15 . The container of  claim 14 , wherein the at least one base wall includes a substantially horizontal shelf extending outward, the substantially horizontal shelf terminating in a substantially vertical, upwardly extending rim wall, said rim wall terminating in the outwardly extending, substantially horizontal base flange. 
     
     
         16 . The container of  claim 15 , wherein the lid comprises a plurality of protruding lid features that extend downward from the lid, wherein when the lid is installed on the base the protruding lid features extend downward along the rim wall of the base toward the substantially horizontal shelf of the base. 
     
     
         17 . The container of  claim 16 , wherein gaps between the protruding lid features are provided in the regions of the attachment tabs so that the protruding lid features do not overlap the attachment tabs, and so that upon reattachment of the lid to the base, the container is ventilated due to openings in the lid resulting from the breaking free of the attachment tabs from the lid. 
     
     
         18 . The container of  claim 16 , wherein in regions proximate the attachment tabs the protruding lid features are located inward of the attachment tabs, so that the protruding lid features do not overlap the attachment tabs, and so that upon reattachment of the lid to the base, the container is not ventilated due to openings in the lid resulting from the breaking free of the attachment tabs from the lid. 
     
     
         19 . The container of  claim 18 , wherein the protruding lid features are located inward from the attachment tabs and are substantially parallel with the hinge edge of the base flange. 
     
     
         20 . The container of  claim 18 , wherein the protruding lid features are proximate the hinge edge of the base flange in regions between the attachment tabs, and are offset inward from the hinge edge of the base flange in regions proximate the attachment tabs, such that the protruding lid features do not overlap the attachment tabs.