Container

Abstract

The container can be locked into a stack of containers. A container cover locks onto the top of a container base to define a sealed area for storage. Additionally, the bottom of a second container base can be locked onto the top of the cover of a first container. In this fashion, when closed containers are stacked, they form a locked stack that is more structurally rigid and therefore less precarious than a traditional, non-locked container stack. When not in use, the bases can be formed into a nested stack, and their covers can be locked together to form a locked cover stack. The locked cover stack can be locked to either the top or bottom of the nested base stack to form a rigid stack. In some embodiments, a cover can be turned upside down and its bottom face locked onto the bottom face of a base.

1 . A first cover for a container, the first cover comprising:
 a first closure portion;   a first engagement portion; and   a central region,   wherein the first closure portion is sealingly engageable with a second closure portion of a base so that when the first and second closure portions are engaged with each other, the first cover and the base define a substantially sealed storage area, wherein the first engagement portion is engageable with a second engagement portion of the base,   the first closure portion comprises locking rings, the locking ring of the first closure portion comprising an inner wall, a retention bead, and an outer wall, and wherein the locking rings include an upper shoulder and a lower shoulder, and each shoulder includes an inner surface and an outer surface;   wherein the respective outer walls of two or more first covers are lockingly engageable to one another in a lid stack,   wherein the outer surface of the upper shoulder of a lower first cover fits inside of, and engages with, the inner surface of the lower shoulder of an upper adjacent first cover, and   wherein the central regions of two or more first covers are engageable with one another in a lid stack and the central regions have sidewalls having at least one protrusion wherein a protrusion of one first cover is engageable with a protrusion of another first cover.   
   
   
       2 . The first cover of  claim 1  wherein the first cover comprises thermoformed plastic. 
   
   
       3 . The first cover of  claim 1  wherein the first engagement portion comprises a cutback. 
   
   
       4 . The first cover of  claim 1  wherein the first engagement portion comprises a rib, and wherein the rib is engageable with a detent groove in the second engagement portion of the base. 
   
   
       5 . The first cover of  claim 1  wherein the first engagement portion comprises a detent groove, and wherein the detent groove is engageable with a rib in the second engagement portion of the base. 
   
   
       6 . The first cover of  claim 1  wherein the first cover comprises a gripping tab. 
   
   
       7 . A first cover for a container, the first cover comprising:
 a first closure portion,   a first engagement portion, and   a central region,   wherein the first closure portion is sealingly engageable with a second closure portion of a base so that when the first and second closure portions are engaged with each other, the first cover and the base define a substantially sealed storage area, wherein the first engagement portion is engageable with a second engagement portion of the base,   the first closure portion comprises locking rings, the locking ring of the first closure portion comprising an inner wall, a retention bead, and an outer wall, and wherein the locking rings include an upper shoulder and a lower shoulder, and each shoulder includes an inner surface and an outer surface,   wherein the respective outer walls of two or more first covers are engageable to one another in a lid stack, and   wherein the outer surface of the upper shoulder of a lower first cover fits inside of, and engages with, the inner surface of the lower shoulder of an upper adjacent first cover, and   wherein the central regions of two or more first covers are engageable with one another in a lid stack and the central regions have sidewalls having at least one protrusion wherein a protrusion of one first cover is engageable with a protrusion of another first cover.   
   
   
       8 . The first cover of  claim 7  wherein the first cover comprises thermoformed plastic. 
   
   
       9 . The first cover of  claim 7  wherein the first engagement portion comprises a cutback. 
   
   
       10 . The first cover of  claim 7  wherein the first engagement portion comprises a rib, and wherein the rib is engageable with a detent groove in the second engagement portion of the base. 
   
   
       11 . The first cover of  claim 7  wherein the first engagement portion comprises a detent groove, and wherein the detent groove is engageable with a rib in the second engagement portion of the base. 
   
   
       12 . The first cover of  claim 7  wherein the first cover comprises a gripping tab. 
   
   
       13 . A first cover for a container, the first cover comprising:
 a first closure portion;   a first engagement portion; and   a central region;   wherein the first closure portion is sealingly engageable with a second closure portion of a base so that when the first and second closure portions are engaged with each other, the first cover and the base define a substantially sealed storage area, wherein the first engagement portion is engageable with a second engagement portion of the base,   the first closure portion comprises locking rings, the locking ring of the first closure portion comprising an inner wall, a retention bead, and an outer wall,   wherein the respective outer walls of two or more first covers are engageable to one another in a lid stack,   wherein the outer surface of the upper shoulder of a lower first cover fits inside of, and engages with, the inner surface of the lower shoulder of an upper adjacent first cover, and   wherein the central regions of two or more first covers are engageable with one another in a lid stack and the central regions have sidewalls having at least one protrusion wherein a protrusion of one first cover is engageable with a protrusion of another first cover.   
   
   
       14 . The first cover of  claim 13  wherein the first cover comprises thermoformed plastic. 
   
   
       15 . The first cover of  claim 13  wherein the first engagement portion comprises a cutback. 
   
   
       16 . The first cover of  claim 13  wherein the first engagement portion comprises a rib, and wherein the rib is engageable with a detent groove in the second engagement portion of the base. 
   
   
       17 . The first cover of  claim 13  wherein the first engagement portion comprises a detent groove, and wherein the detent groove is engageable with a rib in the second engagement portion of the base. 
   
   
       18 . The first cover of  claim 13  wherein the first cover comprises a gripping tab.