Tamper evident locking folded box

Abstract

A tamper resistant latching mechanism is provided with an insert tab and wings on a first section used in conjunction with a slot and release panel on an opposite hingedly connected section.

Claims

1. A container made of a foldable substrate, and said container being of the type having; a bottom rectangular panel foldably connected to lower edges of a rear wall, opposed sidewalls, and a front wall to form a tray defining a storage area within; a top having a rear edge hingedly connected to a top edge of the rear wall of the tray; the top having a top panel with a front edge with a crease line connecting to a front flap section, said crease line having an intermediate section of a cut line defining an opening proximate the path of the crease line; perforations extending inward from the front edge of the top panel at either end of the cut line; a fold line connecting ends of the inward extending perforations, said cut line, perforations, and fold line defining a release panel; the front wall of the tray having a top edge with a crease line connecting to a lower portion of a latch leg; a latch tab attached along an upper portion of the latch leg, said latch tab having a width defined by one or more crease lines less than the length of the cut line along the front edge of the top panel; a wing element attached to a side of the latch tab at a crease line and foldable against the latch tab; wherein the top is a clamshell crown.

2. The container of claim 1 wherein the latch tab has a width defined by a crease along each side, and a wing element attached along each side.

3. The container of claim 1 wherein the wing element attached to the latch tab at a crease line has an opposite crease line defining a second foldably connected wing element.

4. The container of claim 1 wherein gussets connect the ends of the opposed sidewalls to the rear wall and the front wall of the tray.

5. The container of claim 1 wherein the substrate is paperboard.

6. The container of claim 1 wherein the length of the perforations extending downward on the front wall exceeds the length of the latch tab extending from the front edge of the top.

7. A container made of a foldable substrate, and said container being of the type having; a bottom rectangular panel foldably connected to lower edges of a rear wall, opposed sidewalls, and a front wall to form a tray defining a storage area within; a top having a rear edge hingedly connected to a top edge of the rear wall of the tray; the top having a top panel with a side edge with a crease line connecting to a side flap section, said crease line having an intermediate section of a cut line defining an opening proximate the path of the crease line; perforations extending inward from the side edge of the top panel at either end of the cut line; a fold line connecting ends of the inward extending perforations, said cut line, perforations, and fold line defining a release panel; a sidewall of the tray having a top edge with a crease line connecting to a lower portion of a latch leg; a latch tab attached along an upper portion of the latch leg, said latch tab having a width defined by one or more crease lines less than the length of the cut line along the side edge of the top panel; a wing element attached to a side of the latch tab at a crease line and foldable against the latch tab.

8. The container of claim 7 wherein the latch tab has a width defined by a crease along each side, and a wing element attached along each side.

9. The container of claim 7 wherein the wing element attached to the latch tab at a crease line has an opposite crease line defining a second foldably connected wing element.

10. The container of claim 7 wherein gussets connect the ends of the opposed sidewalls to the rear wall and the front wall of the tray.

11. The container of claim 7 wherein the substrate is paperboard.

12. The container of claim 7 wherein the length of the perforations extending downward on the front wall exceeds the length of the latch tab extending from the front edge of the top.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1A is a top plan view of an exemplary unitary blank for a clamshell container prior to folding encompassing the invention;

(2) FIG. 1B is a perspective side view of a clamshell formed from the unitary blank of FIG. 1A;

(3) FIG. 2 is a perspective view of the clamshell container of FIG. 1B with the top or crown portion raised;

(4) FIG. 3 is a perspective view of the clamshell container of FIG. 2 in its closed position, prior to utilizing the latching mechanism;

(5) FIG. 4A is an exterior perspective view of the latching mechanism of the clamshell in FIGS. 1 through 3 in isolation;

(6) FIG. 4B is an exterior perspective view of the latching mechanism showing folding of the latching wings;

(7) FIG. 4C is an exterior perspective view of the latching mechanism with the wings in a folded position;

(8) FIG. 4D is an exterior perspective view of the latching mechanism after it has been inserted into a top edge slot to latch the folding box;

(9) FIG. 4E is an interior perspective view of the latching mechanism showing the wings in partially unfolded state;

(10) FIG. 4F is an interior perspective view of the container showing the wings of the latching tab further unfolded;

(11) FIG. 5A is an isolation exterior perspective view of an alternative latching mechanism with only a single wing to each side of the latching tab;

(12) FIG. 5B is an exterior perspective view of the alternative latching mechanism of FIG. 5A with partially folded wings;

(13) FIG. 5C is an exterior perspective view of the latching mechanism of FIG. 5A with wings folded against the latch tab;

(14) FIG. 5D is an exterior perspective view of the latching mechanism of FIG. 5A with latch tab and folded wings inserted into a top edge slot;

(15) FIG. 6 is a perspective view of a clamshell folding box with the alternative latching tab design of FIG. 5A;

(16) FIG. 7A is a unitary blank for an alternative gusseted food container with a flat top and a latching mechanism according to the disclosure of FIG. 5A;

(17) FIG. 7B is a perspective view of a container formed from the blank of FIG. 7A in its latched configuration.

DETAILED DESCRIPTION OF THE INVENTION

(18) Referring to FIGS. 1 through 4, one embodiment of the invention is depicted in use on a clamshell container 10 that is illustrated in the form of a unitary blank 10a in FIG. 1A and assembled in FIG. 1B as clamshell 10b and closed clamshell 10c in FIG. 3. Most commonly, the unitary blank is made of paperboard and may have various coatings depending upon the particular end use to which it is directed. For instance, interior coatings may increase resistance to heat or liquid contents, and exterior coatings may facilitate printing graphics on the container. Other foldable substrate materials may also be suitable to particular end uses.

(19) In the blank 10a of FIG. 1A, it can be seen that the clamshell has a base portion to the right of crease line 33 and a crown portion to the left of crease line 33. The base portion has a central rectangular bottom panel 19 defined by crease lines 28a-28d. Crease lines 28a and 28c define the connection of rectangular bottom 19 with ridged side panels 12a, 12b. Crease line 28b defines the fold between rectangular bottom 19 and back panel 21b. Crease line 28d defines the folding connection between rectangular bottom 19 and front panel 14. The ends of crease lines 28b, 28d are angled at about 10 degrees to properly shape the triangular corner sections 23a-d. On the ridged side panels 12a, 12b, crease lines 21a, 21b allow the ridged edges to flex. Dashed crease lines 26a-d cooperate with the ends of crease lines 28b, 28d to allow triangular panels 23a-d to be folded. Preferably, these triangular panels are folded inward to create interior gussets. In this fashion, triangular panels 23a and 23c can be adhesively joined to ridged sidewall 12a and triangular panels 23b, 23d can be adhesively joined to ridged sidewall 12b.

(20) The front panel 14 has a top crease 30 that allows movement of the latch leg panel 15 that carries latching tab 16. Latching tab 16 has crease lines 31a, 31b separating foldable first wing sections 17a, 17b. Secondary creases 32a, 32b foldably separate first wing sections 17a, 17b from second wing sections 18a, 18b. Cut lines 29 between latch leg panel 15 and wing sections 17,18 allow wing sections to only be attached at crease lines 31,32.

(21) The crown of the clamshell is constructed in a similar fashion with rectangular top panel 20 separated from side panels 11a, 11b by side folds or crease lines 27a, 27c. Top panel 20 is separated from back panel 21a by crease line 27d and separated from front panel 13 by crease line 27b. Front panel 13 extends from crease line 27b to an opposite distal edge 13b. Crease lines 27b, 27d angle outward at about 10 degrees at their end portions to define the desired shape of triangular sections 22a-d. An added feature of top panel 20 is the release panel 24, which may also be referred to as a tear tab. Release panel 24 is defined by a fold line 36 where it is securely but foldably attached to rectangular top 20. At the opposite side of release panel 24 is cut line 37 that defines a slot 41 (shown in FIG. 4C) along the fold line 27b between front panel 13 and top panel 20. Perforation lines 34, 35 along the sides of release panel 24 allow for the release panel to be pulled open and folded along crease 36 at the rear of panel 24 when it is desired to unlatch the container.

(22) Triangular panels 22a-22d are also used to form the crown with triangular sections 22b, 22d folded along crease lines 25b, 25d inward to be adhesively attached to side panel 11b, and triangular panels 22a, 22c folded inward along crease lines 25a, 25c to be attached to side panel 11a. The structure of the assembled clamshell blank 10b with triangular panels attached to sidewalls is shown in FIG. 1B. It can be seen that the sidewalls 11, 12 and front walls 13, 14 and rear walls 21a, 21b are folded at angles so that they extend outward from the rectangular top and bottom panels 19, 20 at angles of approximately 100 degrees rather than extending vertically at 90 degrees. This outwardly expanding of both the tray and crown openings allows assembled clamshell boxes to be nested in the form of space saving stacks prior to use.

(23) FIG. 1C shows the clamshell box 10b of FIG. 1B with the crown portion, including top panel 20, folded upward. FIG. 3 shows the clamshell 10c in its fully closed but still unlatched configuration. It can be seen in FIG. 3 that the ridged sidewalls 12a, 12b have folded interior crown sidewalls 11a, 11b with the creases 21a, 21b facilitating the bending of the upper ridged portions inward corresponding to the inward taper of sidewalls 11a, 11b as those sidewalls near the top panel 20.

(24) It will also be understood that latch leg 15 is foldable along crease line 30 so that the attached central latch tab 16 can be moved toward and away from the rectangular top 20 as needed for latching. It can also be seen that the front wall 13 of crown portion of the clamshell fits so that its distal edge 13a is interior of the front wall 14 of the clamshell base. The result is a closed container with overlapping sidewalls 11, 12 and overlapping front walls 14, 13.

(25) To operate the latching mechanism, the latch leg 15 is folded slightly away from the rectangular top panel 20 thereby providing space or clearance to assemble the latching tab. Latching tab consists of the insert tab 16 and one or more wings. In the illustrated embodiment of FIG. 4A, it can be seen at latching tab 16 has immediately adjacent wings 17a, 17b that fold along creases 31a, 31b on either side. Second wing segments 18a, 18b fold with respect to the first adjacent wing segments 17a, 17b along crease lines 32a, 32b. In an optimized configuration, the fold lines are manipulated so that secondary panels 18 and adjacent panels 17 form a Z shape (or mirrored Z-shape) with respect to the insert tab 16, as reflected in FIG. 4B. The wing panels are then compressed against the insert tab 16 as shown in FIG. 4C, so that effectively there is only a single insert tab shape that has no greater width than the insert tab 16 but may have additional thickness due to the additional layers of material from one or more folded wing elements, such as first and second segments 17a, 17b and 18a, 18b.

(26) Turning then in particular to the release panel 24 shown in FIG. 4C, it can be seen that the cut line 37 at the front of release panel 24, and folding front panel 13 respective to top panel 20 creates a slot 41. The release panel or tear tab 24 is further defined by perforated sides 34, 35 and rear fold line 36. In operation, the insert tab 16 and associated wing elements are folded and inserted into slot 25 by pivoting latch leg 15 along crease line 30 into a forward position toward the top 20. As shown in FIG. 4E, once the insert tab 16 is interior of the slot 25, the wing sections 17, 18 begin to unfold and expand and form a locking or latching mechanism that prevents the front panel of the tray portion from disengaging from the front panel of the crown portion of the clamshell. The result is a simply latched clamshell container. However, the operation of release panel 24 creates a novel tamper resistant and reusable latching mechanism.

(27) It can be seen from FIGS. 4E and 4F that the wing segments 17, 18 are not able to be withdrawn through the slot 41 that was created along cut line 37, since the wing segments cannot be accessed to be refolded and pressed against the latch tab 16 on the interior side of the assembled and latched container. This presents two possible avenues for opening the latched container, one by brute force and one by finesse.

(28) The brute force method is to simply pull the front panel 14, and possibly latch leg 15 away from the crown portion. This action will tear the wings 17, 18 from the sides of insert tab 16, typically along crease lines 31a, 31b and depositing those paperboard wing elements into the food within the container. While this will accomplish the objective of demonstrating tampering with the clamshell container, it is also apparent that the latching mechanism is destroyed by this action and the food container will no longer remain latched. Accordingly, if the food container held a twelve slice cake and only four slices were consumed when the container was first opened, the end user is left with a less than optimal receptacle for the remaining eight slices of cake.

(29) The second, and preferred, alternative for opening the latched food container is to utilize release panel 24 to expose the latch tab 16. To open the container in this fashion, the front of panel 24 (which may have a protruding lip) is lifted upward from the rectangular top 20. The release panel 24 will pivot from its rear edge along fold line 36 and tearing perforations 34, 35 defining the sides of the release panel 24. When the release panel 24 is folded upward to a nearly vertical position, the inserted latch tab 16 and its associated wing elements 17,18 can be accessed and removed through the larger rectangular opening that has been created. When this alternative is used, it is apparent that the packaging has been opened because the perforated sides 34, 35 of the release panel 24 have been torn. Even with perforated sides 34,35 being torn, however, the latching mechanism of latch tab 16 and its wing elements remains effective and the container can be reclosed by the consumer if, for instance, the food contents within are not completely consumed.

(30) To provide optimal access to the latch tab 16, it is desirable that the length of perforations 34, 35 be slightly greater than the length of latch tab 16. This allows for a size of opening under the release tab 24 to permit latch tab 16 to be grasped and removed in a fashion that minimizes the likelihood of damaging the attachment of the wing elements 17,18.

(31) A simplified latch construction is illustrated in FIGS. 5A-5D. In this example, the latch tab 38 has single wing elements 39a, 39b extending to either side and separated by fold lines 40a, 40b. The wing elements 39 are separated from the latch leg 15 for insert tab 38, by cut lines 29. In use, wing elements 39a, 39b are folded inward as shown in FIG. 5B and compressed against latch tab 38 which is in turn folded along crease 26 and inserted into slot 41. The use of single wing elements 39 simplifies the assembly of the folded latch tab 38 with its associated wing elements, reducing the dexterity needed to prepare the latched container.

(32) A wing configuration of FIGS. 5A-D is illustrated on a clamshell container 10d in FIG. 6. The need for only two fold lines 40a, 40b simplifies the preparation of both the unitary blank and the actual use of the latching mechanism. In fact, a working latch tab 38 can be made with only a single wing element extending to one side.

(33) It can also be appreciated that a latching mechanism according to this invention, can be utilized in other container configurations such as box shown in FIGS. 7A, 7B. This box has a flat top panel 120 with the insert tab 138 formed as a forward extension of the top panel 120. This structure uses the fold line 127 that allows the entire top panel 120 to pivot from its rear edge into open and closed positions, to also act as the latch leg and allow for insertion of the latch tab 138 into the slot created along cut line 137. It can be seen that such a box may contain gussets formed by adhering triangular panels 122a, 123a together, preferably in an inward directed fashion, although exterior gussets are also possible. Side panels 112a, 112b of the rectangular bottom 119 can be folded inward along creases 128as, 128b to create sidewalls and then inward facing cover side flaps 148a, 148b folded inward along creases 147a, 147b will cover a substantial portion of the storage space within the container. Additional cover is provided by front wall flap 149, that may be folded inward along crease 115 forming the distal edge front panel 114. The illustrated crease 115 also contains cut line 137 that creates the slot ultimately used by insert tab 138 from the folded top 120 as reflected in the assembled configuration of FIG. 7B.

(34) From these examples, it can be seen that the latch tab can be suitably mounted to the front of either a lower tray section or an upper top or crown section of a box. Latch tabs may also be mounted at the tops of side walls to engage with slots along the top side edges of top or crown sections. A single container may have more than one latch according to the invention, for instance, two latches spaced apart along a front of the container, or a latch on each of the left and right sides of the container. The release panel or tear tab should be located either at a top of the container or at the top of a front or side wall of the container, as if perforations for the tear tab were along a bottom or wall bottom, it would engender leakage from the container.

(35) Numerous alterations of the structure and techniques herein disclosed will suggest themselves to those skilled in the art. However, it is to be understood that the present disclosure relates to the preferred embodiment of the invention which is for purposes of illustration only and not to be construed as a limitation of the invention. All such modifications which do not depart from the spirit of the invention are intended to be included within the scope of the appended claims.