Tamper-evident tab thermoformed packaging

Abstract

A package having a lid seated on a base where the edge of the seated lid is generally inaccessible due to contours in the base, and where the edge is made accessible by a tamper-evident tab arrangement. The base includes a tamper-evident tab and a fixed tab disposed on a flange extending about the base. The tamper-evident tab is joined to the base on opposite ends by a breakable land and a permanent land. The tamper-evident tab is movable by breaking the tamper-evident tab free from the base on one end by breaking the breakable land and bending the tamper-evident tab out of the way about the permanent land to provide access to the peripheral edge of the lid. The tamper-evident tab may include an extension adjacent to the breakable land and the fixed tab may include an extension adjacent to the tamper-evident tab extension opposite the breakable land.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows: 
     
         1 . A thermoformed package comprising:
 a thermoformed lid having a shoulder and a peripheral edge extending outwardly from said shoulder;   a thermoformed base having a bottom, a sidewall extending generally upwardly from said bottom and a flange extending outwardly from said sidewall around a periphery of said base, said sidewall including an annular shoulder extending at least partially around said base, said base shoulder configured to interlock with said lid shoulder when said lid is installed on said base;   said flange including an annual upwardly extending rail, said rail having dimensions only slightly greater than those of said peripheral edge of said lid, whereby said rail impedes access to said peripheral edge of said lid when said lid is installed on said base;   said flange including a fixed tab and a tamper-evident tab, said tamper-evident tab including a portion of said rail and underlying a significant portion of said peripheral edge of said lid when said lid is installed on said base, said tamper-evident tab joined to said flange at a first radial end by a first land and a second radial end by a second land, said tamper-evident tab including an extension adjacent to a first radial end, said fixed tab including an extension disposed adjacent said first radial end opposite said first land, said tamper-evident tab being selectively movable from a closed position to an open position by manually gripping said fixed tab extension and said tamper-evident tab extension and then breaking said first land and bending said tamper-evident tab out of alignment with said flange about said second land without breaking said second land such that said tamper-evident tab remains connected to said flange, movement of said tamper-evident tab into said open position exposing a portion of said peripheral edge of said lid, whereby said peripheral edge of said lid can be gripped by a user and used to lift said lid from said base.   
     
     
         2 . The thermoformed package of  claim 1  wherein said annular shoulder and said peripheral edge are generally circular and generally concentric, whereby said lid can be installed on said base in any rotational position. 
     
     
         3 . The thermoformed package of  claim 1  wherein said peripheral edge includes a generally planar portion, said tamper-evident tab include a generally planar portion underlying said planar portion of said lid, whereby movement of said tamper-evident tab to said open position exposed said planar portion of said lid. 
     
     
         4 . The thermoformed package of  claim 1  wherein said tamper evident tab has an inward edge unconnected to said flange. 
     
     
         5 . The thermoformed package of  claim 1  wherein said base and said lid are generally rectangular, said tamper-evident tab being disposed in a first corner of said base. 
     
     
         6 . The thermoformed package of  claim 5  wherein said sidewall includes a first corner having an angled wall segment, said tamper-evident tab extending outwardly from said angled wall segment. 
     
     
         7 . The thermoformed package of  claim 6  wherein said fixed tab extends outwardly from said angled wall segment adjacent to said tamper-evident tab. 
     
     
         8 . The thermoformed package of  claim 1  wherein said sidewall include four primary wall segments extending in a generally rectangular arrangement and an additional corner wall segment extending between an adjacent two of said primary wall segments in a first corner of said base, said corner wall segment including a portion of said annular shoulder, said tamper-evident tab and said fixed tab extending outwardly from said corner wall segment. 
     
     
         9 . The thermoformed package of  claim 8  wherein each of said primary wall segments is generally convex with an outermost extent of each primary wall segment being outwardly offset from opposed ends of said primary wall segment by a first distance, said tamper-evident tab extension and said fixed tab extension extending beyond said outermost extents of said primary wall segments adjacent to said corner wall segment by a distance that is approximately twice said first distance, whereby said tamper-evident tab and said fixed tab can extend beyond said outermost extents while allowing a plurality of the thermoformed packages to be arranged in an array without interference from said tamper-evident tab or said fixed tab. 
     
     
         10 . A thermoformed package comprising:
 a base defining an opening, said base including a flange extending around said opening, said flange including:
 an annular upwardly extending rail, 
 a tamper-evident tab movable from a closed position to an open position, said tamper-evident tab including a portion of said rail and extending inwardly a substantial distance from said rail, said tamper-evident tab joined to said flange at a first radial end by a first land and a second radial end by a second land, said tamper-evident tab including an extension adjacent to said first radial end, and 
 a fixed tab disposed adjacent to said tamper-evident tab, said fixed tab including an extension disposed adjacent said first radial end opposite said first land; and 
   a lid releasably fitted to said base over said opening, said lid terminating in a peripheral edge adjacent to an inward side of said rail, whereby said rail impedes access to said peripheral edge when said lid is installed on said base;   wherein said tamper-evident tab is selectively movable from a closed position to an open position by manually gripping said fixed tab extension and said tamper-evident tab extension and then breaking said first land and bending said tamper-evident tab out of alignment with said flange about said second land without breaking said second land such that said tamper-evident tab remains connected to said flange, movement of said tamper-evident tab into said open position exposing a portion of said peripheral edge of said lid, whereby said peripheral edge of said lid can be gripped by a user and used to lift said lid from said base.   
     
     
         11 . The thermoformed package of  claim 10  wherein said lid includes an annular shoulder configured to interlock with a corresponding annular shoulder in said base, and said peripheral edge and said annular shoulder are generally circular and generally concentric, whereby said lid can be installed on said base in any rotational position. 
     
     
         12 . The thermoformed package of  claim 10  wherein said peripheral edge includes a generally planar portion, said tamper-evident tab include a generally planar portion underlying said planar portion of said lid, whereby movement of said tamper-evident tab to said open position exposed said planar portion of said lid. 
     
     
         13 . The thermoformed package of  claim 12  wherein said tamper evident tab has an inward edge unconnected to said flange. 
     
     
         14 . The thermoformed package of  claim 10  wherein said base and said lid are generally rectangular, said tamper-evident tab being disposed in a first corner of said base. 
     
     
         15 . The thermoformed package of  claim 14  wherein said base includes a sidewall, said sidewall including a first corner having an angled wall segment, said tamper-evident tab extending outwardly from said angled wall segment. 
     
     
         16 . The thermoformed package of  claim 15  wherein said fixed tab extends outwardly from said angled wall segment adjacent to said tamper-evident tab. 
     
     
         17 . The thermoformed package of  claim 10  wherein said base includes a sidewall, said sidewall including four primary wall segments extending in a generally rectangular arrangement and an additional corner wall segment extending between an adjacent two of said primary wall segments in a first corner of said base, said corner wall segment including a portion of said annular shoulder, said tamper-evident tab and said fixed tab extending outwardly from said corner wall segment. 
     
     
         18 . The thermoformed package of  claim 17  wherein each of said primary wall segments is generally convex with an outermost extent of each primary wall segment being outwardly offset from opposed ends of said primary wall segment by a first distance, said tamper-evident tab extension and said fixed tab extension extending beyond said outermost extents of said primary wall segments adjacent to said corner wall segment by a distance that is approximately twice said first distance, whereby said tamper-evident tab and said fixed tab can extend beyond said outermost extents while allowing a plurality of the thermoformed packages to be arranged in an array without interference from said tamper-evident tab or said fixed tab. 
     
     
         19 . A tamper-evident food package comprising:
 top and bottom parts capable of being selectively interlocked to close the package, said top and bottom parts shaped to cooperatively define an article-receiving space when interlocked, said bottom part including a circumferential flange with a rim extending around said flange adjacent to an outer edge of said flange, said top part including a peripheral edge terminating inwardly of said rim, whereby access to said peripheral edge is impeded by said rim;   said flange including a tamper-evident tab movable between a closed position and an open position, said tamper-evident having a first radial end joined to said flange by a breakable land and a second radial end joined to said flange by a permanent land, said tamper-evident tab having an extension extending outwardly from said tamper-evident tab adjacent to said breakable land and remote from said permanent land, said tamper evident tab including a portion of said rim, whereby movement of said tamper-evident tab moves said portion of said rim away from said top part to expose a portion of said peripheral edge;   said flange further including a fixed tab disposed adjacent to said breakable land opposite said tamper-evident tab, said fixed tab including an extension extending outwardly from said flange, whereby a user can remove said top part from said bottom part by gripping said fixed tab with one hand, gripping said tamper-evident tab extension with the other hand and applying force in such a way as to first break said breakable land and second bend said tamper-evident tab away from its closed position about said permanent land without breaking said permanent land such that said tamper-evident tab remains connected to said flange.