Stackable food container with lid

Claim 1

A package comprising a tray and a cover, said tray being formed of a resin and having a bottom, vertically extending sidewalls joined together at corners and having an open upper end, and a horizontally extending sealing surface adjacent the open upper end of said sidewalls, vertically extending flutes on the exterior of said sidewalls to increase structural stability, said flutes extending outwardly of the sidewall, one of said flutes at each vertically extending corner extends from one sidewall to the other, an outwardly extending flange on the sidewalls adjacent said open upper end, said flange comprising said sealing surface, a transparent sealing sheet extending across said upper end of said tray and sealingly bonded to said flange after goods have been placed in said tray to thereby seal said gods in air-tight relationship within said tray, an outwardly projecting shelf formed only at each corner, each said shelf being located intermediate the sidewall flange and the tray bottom, each said shelf extending a distance outwardly whereby it will engage the surface of a flange corresponding to said flange if inserted into an identically shaped tray to thereby space apart the bottoms of such trays, said cover being integrally formed with said flange and including a generally planar surface which is about the same size and configuration as said bottom of said tray, a mating lip on said cover extending around and transverse to the planar surface, at least part of said mating lip circumscribing a cross-sectional area parallel to said planar surface which is greater than the cross--sectional area circumscribed by said flange n a plane parallel to said open upper end, means forming a hinge between said cover and said flange, said cover having an upper surface configured to receive a surface corresponding to the lower surface of said tray bottom and hold it in general vertical alignment in a stack of covered trays, the lip including an outwardly extending shoulder at its periphery to hold the cover in a stable configuration and minimize bowing of the cover intermediate the corners of the tray, locking beads formed in said lip being configured to snap into place below said flange on said sidewalls and thereby pull said planar surface of said lid downward into contact with said sealing sheet in a locked position, said planar surface depressing said sealing sheet about 0.03 inches below the surface of said flange and into engagement with the goods in said tray.