BACKGROUND OF THE INVENTION
Food is often placed in a transparent plastic container that includes a base with a large volume cavity that holds the food and with a lid that closes the cavity. Buyers want to be assured that, after the food was placed in the container as by a clerk at the food store, that the container has not been opened. There is a possibility that another customer has secretly opened the container to taste a bit of the food before closing it (and possibly leaving germs). Potential customers want to be assured that this has not happened.
Most lids have a periphery that is constant throughout the entire 360° periphery of the lid, and with the entire lid lying on top of a portion of the base, rather than inside the base. A container that could be easily closed by a clerk at a store after he/she loaded food into the base cavity, which automatically latched the lid closed so it required a customer to tear an exposed portion of the container to open the lid, and which formed a seal between the base and lid without the lid having to move down into the base cavity, would be of value.
SUMMARY OF THE INVENTION
In accordance with one embodiment of the present invention, a container is provided of the type that includes a sheet plastic base and lid which prevents the lid from opening the first time unless a barrier is broken, wherein the lid periphery has a simple outer lid rim part extending along almost its entire periphery and wherein the lid seals to the base without requiring the lid to be inserted into the base cavity. The base has a raised base outer rib extending along almost the entire base periphery and has a flat base seal wall inward of the base outer rib. The lid has a lid rim part with a radially (with respect to the container axis) outer rim part that lies flat against the flat base seal wall and with an outer edge that lies substantially against the base outer rib. As a result, the base outer rib prevents a person from grasping the lid rim part to lift the lid. However, there are two gaps in the base outer rib, with means in the gaps for moving a tab that includes a limited length of the base outer rib. When the tab is moved out of the way, a person can grasp the lid rim part and lift the lid.
To seal the base to the lid, the base is provided with an upstanding projection lying radially inside the base outer rib, and the lid is provided with a downwardly-opening groove that receives the projection and seals to it. The projection has primarily vertical inner and outer walls and the groove has inner and outer walls that receive the projection. The inner and outer walls of the projection and groove are closer together at the bottom than at the top, to provide a seal and to resist opening of the container.
The novel features of the invention are set forth with particularity in the appended claims. The invention will be best understood from the following description when read in conjunction with the accompanying drawings.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded isometric view of a container of the invention, with the lid spaced over the base.
FIG. 2 is an isometric view of the container of FIG. 1 with the lid fully closed on the base.
FIG. 3 is a plan view of the container of FIG. 2.
FIG. 4 is a sectional view taken on line A-A of FIG. 3.
FIG. 5 is an enlarged view of area B-B of FIG. 4.
FIG. 6 is a plan view of only the base of FIG. 1.
FIG. 7 is a plan view of area C-C of FIG. 6.
FIG. 8 is a plan view of an area of a variation of the invention of FIG. 1 wherein one gap line is a hinge rather than a tear line.
FIG. 9 is a partial isometric view of the container of FIG. 7 wherein the tab has been moved out the way but the lid has not yet been opened.
FIG. 10 is a view similar to that of FIG. 9 but with the lid having been raised.
FIG. 11 is an exploded isometric view of a container of a different shape (round periphery).
FIG. 12 is an isometric view of the closed container of FIG. 11.
FIG. 13 is a plan view of the container of FIG. 12.
FIG. 14 is a sectional view taken on line D-D of FIG. 13.
FIG. 15 is an enlarged view of area E-E of FIG. 14.
FIG. 16 is a partial isometric view of the base of a container that is a variation of FIG. 11, wherein the separation line is a wide slot and the gap lines at opposite sides of the tab are tear lines.
FIG. 17 is an isometric view of the base of a container of another variation of FIG. 11, wherein the separation line is a tear line.
FIG. 18 is a partial isometric view of an opened container of another embodiment of the invention wherein a lid latch enters a base slot when the container is closed.
FIG. 19 is an isometric view of the region shown in FIG. 18, but with the container closed.
FIG. 20 is a sectional view taken on line E-E of FIG. 19.
FIG. 21 is a partial isometric view of the base of a container similar to that of FIG. 8, but with the base support wall having dimples to rigidize it.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a container 10 that includes base and lid elements comprising a base 12 and a cover or lid 14, that are centered on a vertical axis 16. The base has a cavity 20 with primarily vertical side walls 22 and a bottom wall 24. The base also has a base rim portion 30 that overhangs the side walls (i.e. the rim portion extends radially further from the axis than adjacent upper ends of the side walls 22). It can be seen that the base rim portion has a raised base outer rib 32 that extends around at least three-quarters, or 2700, of the axis and that forms an upward projection part. The base rim portion 30 also has a raised base inner rib 34 that forms an upward projection, and the base rim portion also has a horizontal base support wall 36 that lies radially between the inner and outer ribs 34, 32.
The lid 14 has a center portion 40 that lies over most of the cavity when the container is closed, and has a lid rim portion 42 that lies radially outward of the center portion. The lid rim portion forms a lid groove rib 44 that forms a downward opening groove 46. The lid rim portion 42 also has a lid outer rim part 50 with an outer edge 52, and that lies on the base support wall 36 when the container is closed.
FIG. 2 shows the closed container, and shows an access region 60 where there are two gaps 62, 63 in the base outer rib 32 and a move-away tab 64 that spans most of the access region. The tab subtends an angle H of about 20° to 30°. To open the container a person must raise the lid rim part 50 by first lifting the lid outer edge 52. A base outer rib part 62 on the tab blocks access to the lid outer edge 52. The tab 64 is connected to the rest of the base rim portion 36 by a pair of gap lines 70, 72 that lie in the gaps at either end of the tab. The base has a separation line 74 that lies radially inward of the base outer rib. A customer who buys the food package can open it by tearing one end of the tab along a tear line such as 70, so the tab can be moved out of the way. Then, the customer can grasp the lid rim part 52 to lift the lid and open the base cavity.
FIGS. 4 and 5 show the closed container at the tab 64, showing the lid rim portion which includes the lid groove 46, the lid rim part 50 which extends beyond the base side walls 22 and the lid rim outer edge 52. FIG. 5 shows that the base outer rib part 62 has a radially inner wall 80 with an overhang 82 that makes the inner surface of the inner wall vertically undercut. That is, when an attempt is made to lift the lid outer edge 52, such lifting is impeded by the overhang 82. As a result, it requires more force to lift the lid to deflect the lid rim part 50 so it can clear the overhang 82, and a person must have a firm grasp of the lid rim to do so. The separation line 74 at the radially inner end of tab 64 is a narrow line of a radial width that is preferably no more than one millimeter, to prevent a person from pushing up the lid rim part 50 by projecting a narrow instrument through the slit of the separation line. The overhang 82 also prevents a person from inserting a fingernail along the inner wall to bend up the lid outer edge 52. It can be seen that the separation line 74 is spaced a plurality of millimeters radially inward of the lid outer edge 52, to facilitate grasping the lid when the tab is moved out of the way.
FIG. 5 shows that the upper surface 38 of the base support wall 36 is flat, and that the bottom surface 51 of the lid rim part 50 is also flat and extends parallel to and adjacent to the surface 38 (as viewed radially or circumferentially). This makes it difficult for a person to lift the lid rim part 50 until the tab is moved to move the base support wall 36 downward and leave the bottom of lid rim part 50 exposed. A lid groove wall 92 is joined by a resilient curve 85 to the lid rim part 50 and presses the lid rim part 50 firmly against the base support wall 36.
FIG. 5 shows that the downwardly-opening lid groove 46 is formed by radially inner and outer groove walls 90, 92 and a top wall 94. The upward projection formed by the base inner rib 34 also has radially inner and outer rib walls 100,102 and a top wall 104. When the base inner rib is pushed upward into the groove, the radially inner and outer walls of the base rib and lid groove tightly engage one another to form a seal. The seal resists the passage of fluids such as air that would reduce the freshness of the food. The radially inner and outer walls of the base inner rib and of the lid groove, converge downwardly at an angle G of a plurality of degrees but less than 60°, with a preferred angle being about 20°. The angling from the vertical results in the opposite side walls of a part such as the base rib walls 100, 102, converging in a downward direction. This convergence at an angle of a plurality of degrees facilitates the lid groove walls pressing firmly against the base inner rib walls, and also provides resistance to opening the lid. The seal between the base and lid occurs at the top of the lid and above the food-holding cavity 20, rather than at a location within the food-holding cavity 20, so the sealed surfaces are unlikely to be contaminated by the food if the cavity has been overfilled.
FIG. 7 shows that both gap lines 70, 72 are designed to be easily torn, by providing a plurality of elongated slits 110 and shorter connections 112 and by providing lead-ins 114. It is also possible to provide a scored line that facilitates tearing. It is necessary to tear only one of the two tear lines 70, 72 to pivot the tab out of the way about the other tear line. FIG. 8 shows a modified tab 120 which is connected at the gaps at its opposite ends by one tear line 122 and by one pivot line that forms a hinge 124 that cannot be easily torn. FIGS. 9 and 10 show how a tear line 122 can be torn and the tab 120 can be pivoted out of the way so a person can grasp the lid rim part 50 to pull up the lid with a sufficient upward force (e.g. 2 pounds) to open the lid.
FIG. 1 shows that the center portion 40 of the top of the lid which lies over the cavity 20, has an upward projection 130 and that the bottom wall 24 of the base has a recess 132 in its bottom. This allows a plurality of closed containers to be stacked one on another, without requiring a plurality of projections and recesses to be aligned.
FIG. 11 shows a container 140 comprising a base 142 and lid 144 that have round peripheries centered on a container axis 146. The base forms a move-away tab 150 with gap lines 152, 154 at its opposite ends, and with a wide slot 160 that separates the tab from base portions that lie radially inward of the tab. FIG. 15 shows that the slot has a radial width of about 3 millimeters. The advantage of a wider slot is that the slot can be cut more reliably than a thin slot. However, as mentioned earlier, a wider slot allows someone to try to push up the lid by a projection pushed up through the slot. It is also possible to form the separation line as a tear line (FIG. 17) that can be easily torn, so a projection cannot be readily inserted up through the separation line.
The lids of FIGS. 1-17 can be closed at any orientation of the lid about the container axis (or at any of four orientations for the largely rectangular container of FIG. 1), with respect to the base. This facilitates closing of the containers.
FIG. 18 shows a portion of a container 170 with a base 172 and lid 174, wherein the base has a move-away tab 176 of different design. The tab has a base outer rib portion 180 with a slot 182 in its radially inner wall 184. The slot 182 receives a largely radially-outwardly projecting latch 186 of the lid rim part 190. When the lid is being closed, the latch is resiliently bent by the base inner wall 184 until the latch snaps into the slot 182. FIG. 19 shows the lid fully closed on the base, with the latch 186 received in the slot. FIG. 20 is a sectional view showing the latch 186 in the slot 182. The latch extends so far radially outward into the slot 182, that even if the latch is pushed upward and radially inward as to 186A, it is very difficult to move the latch up past the slot top edge 190. The tab can be moved out of the way to enable lifting the latch, by tearing one of the gap lines 192,194 (FIG. 18) so the fact that the container was opened is obvious. A narrow separation slit 196 is shown. Of course, one end of the move-away tab can have a hinge instead of a tear line that also serves as a hinge, and the separation line can have a tear line or a wide slot instead of a narrow slot.
FIG. 21 shows a base 200 similar to the one in FIG. 8, but with the base support wall 36 having dimples 202. The dimples do not lie inward of the tab 120, and the dimples are covered by the lid when the container is closed. The dimples increase the rigidity of the base support wall.
The base and lid can be made from one of two pieces of sheeting, of a variety of materials. These include Oriented Polystyrene (OPS), Talc-Filled Polypropylene (TEPP), High Impact Polystyrene (HIPS), Polypropylene (PP), Polythylene Terepthalate (PET), Amorphous PET (APET), Crystallized Polyethylene (CPET), polyacid (PLA), Polystyrene, Styrene Block Copolymer blends as well as Biodegradable and Compostable Fiber materials. The sheet thickness is preferably 0.01 to 0.07 inch thick.
Thus, the invention provides a container wherein the lid can be easily closed on the base, and thereafter the container resists initial opening of the lid until a move-away tab is torn and moved out of the way so a lid rim part can be grasped to lift the lid. The base has a base outer rib with a vertically undercut inner wall that resists lid lift-up. There are gaps at circumferentially opposite ends of the tab, with gap lines in the gaps and with at least one of the gap lines being a tear line that can be torn. The base also has an upward projection formed by a radially inner rib, that fits into a groove in the lid to form a seal between them, with the seal lying above the food-holding cavity. In one type of container the lid has a lid rim portion of uniform shape around its entire periphery, and the lid can be installed in a plurality of positions turned about the container axis from one another. In another container, the lid has a projection at at least one location that fits into a slot in the radially inner wall of the tab.
Although particular embodiments of the invention have been described and illustrated herein, it is recognized that modifications and variations may readily occur to those skilled in the art, and consequently, it is intended that the claims be interpreted to cover such modifications and equivalents.