Tab lock closure for a container

[0017]The invention will now be described with reference to the drawing figures, in which like reference numerals refer to like parts throughout. For purposes of clarity in illustrating the characteristics of the present invention, proportional relationships of the elements have not necessarily been maintained in the drawing figures.

[0018]The following detailed description of the invention references specific embodiments in which the invention can be practiced. The embodiments are intended to describe aspects of the invention in sufficient detail to enable those skilled in the art to practice the invention. Other embodiments can be utilized and changes can be made without departing from the scope of the present invention. The present invention is defined by the appended claims and the description is, therefore, not to be taken in a limiting sense and shall not limit the scope of equivalents to which such claims are entitled.

[0019]Referring to the figures, one embodiment of the present invention is directed to a carton or container 10 having an integral tab lock closure 12 adapted for retaining end flaps of the container 10 in a closed and releasably locked orientation. It will be appreciated that the tab lock closure 12 may be suitably implemented with containers and cartons configured, shaped and designed differently than the container 10 illustrated in the figures.

[0020]The container 10 may be constructed of paperboard, laminated paperboard, cardboard, polymers, thermoplastic materials, molded pulp fiber, laminated molded pulp fiber or any other suitable material now known or hereafter developed. The container 10 may be coated on its interior and/or exterior surfaces with a waterproof or water-resistant material such as polyethylene, polypropylene or polyester. The container 10 may also have designs, labels or other indicia printed or placed thereon.

[0021]As illustrated in the figures, the container 10 may include four primary panels including a front panel 14, rear panel 16, first side panel 18 and second side panel 20. The panels 14, 16, 18, and 20 may be foldably connected by score lines or panel fold lines 22, 24 and 26, as best shown in FIG. 5. A glue flap 28 may also be foldably connected to one of the panels by a score line or glue flap fold line 30, such as the rear panel 16 as shown in FIG. 5, according to one embodiment of the present invention. The glue flap 28 may be suitable for being adhesively joined to an adjacent panel when the container 10 is formed, such as the first side panel 18 as shown in FIG. 5. Several alternative embodiments are envisioned for the container 10. For example, rather than glue flap 28 and glue flap fold line 30, the panels 14, 16, 18, and 20 may be connected to one another through gusset panels that may be folded to form a box-like container. Several other methods for forming a container from a unitary blank are known to those skilled in the art.

[0022]Container 10 may include an end construction 31 at one or both ends of container 10. End construction 31 may include end flaps 32, 34, 36, and 38 connected to panels 14, 16, 18, and 20 as explained in greater detail below. The figures illustrate one embodiment where container 10 has identical end constructions 31 at both ends; however, in alternative embodiments, container 10 is designed with an end construction 31 at one end that is different from the end construction of the other end.

[0023]End construction 31 may be constructed in the following manner according to one embodiment of the present invention. An opposing pair of first and second minor end flaps 32 and 34 may be connected to the ends of first and second side panels 18 and 20, respectively, as best shown in FIG. 5. First and second minor flaps 32 and 34 can be connected to side panels 18 and 20 by score lines or end flap fold lines 40 and 42, respectively. Similarly, and opposing pair of first and second opposing major end flaps 36 and 38 may be connected to the ends of the front and rear panels 14 and 16, respectively, by score lines or end flap fold lines 44 and 46, respectively, as best shown in FIG. 5. First major end flap 36 includes a distal edge 52 and two opposing side edges 54 and 56. According to the embodiment shown in the figures, distal edge 52 is substantially parallel to end flap fold line 44 and opposing side edges 54 and 56 are substantially perpendicular to distal edge 52. However, distal edge 52 need not be parallel to end flap fold line 44, and opposing side edges 54 and 56 need not be perpendicular to distal edge 52. The distal edge 52 and opposing side edges 54 and 56 define the perimeter of the first major end flap 36 along with end flap fold line 44. Second major end flap 38 includes a distal edge 58 and two opposing side edges 60 and 62. Similar to first major end flap 36, distal edge 58 and opposing side edges 60 and 62 may be constructed with any number of different orientations and define the perimeter of second major end flap 38 along with end flap fold line 46.

[0024]Within end construction 31 may be the tab lock closure 12. Again, it will be understood that the tab lock closure 12 of the present invention can be implemented with containers and cartons of designs different from that shown in the example provided in the figures.

[0025]Tab lock closure 12 may be constructed from at least one tab 48 and at least one corresponding aperture 50. According to the embodiment shown in the figures, tab lock closure 12 includes one tab 48 and one aperture 50. However, in alternative embodiments, tab lock closure 12 can include two or more tabs 48 and two or more corresponding apertures 50. The tab 48 may be in the form of a tab, tongue ear, projection or other suitable locking element, while the aperture 50 may be in the form of an aperture, slot, slit, notch or other opening suitable for engagement by tab 48.

[0026]Tab 48 may be cut from first major end flap 36 such that first major end flap 36 includes a tab cut line 64 defining the tab 48, as best shown in FIG. 5. In one embodiment of the present invention, tab 48 is cut from first major end flap 36 and remains connected to front panel 14 by a score line or tab fold line 66. In an alternative embodiment, tab 48 is affixed to major end flap 36 and/or front panel 14 rather than being cut out of first major end flap 36. Tab fold line 66 and end flap fold line 44 may be located along a common axis, as best shown in FIG. 5. In such an embodiment, tab fold line 66 and flap fold line 44 are generally axially coextensive with one another such that both form part of a single fold line. In an alternative embodiment, tab fold line 66 may also be offset from end flap fold line 44. The tab cut line 64 may extend slightly past fold line 66 in order to create two tab extension cuts 72. The tab extension cuts 72 may extend slightly into panel 14 and take the form of a cut, slit, or notch. The tab extension cuts 72 facilitate operation of the tab lock closure 12 by allowing slight lateral movement of the tab 48 in a direction represented by arrow 76, as shown in FIG. 4 and further discussed below, when it is moved from a locked orientation to an unlocked orientation.

[0027]Tab 48 may include a distal end 70 on its end opposite tab fold line 66, as shown in FIG. 2. The distal end 70 may have a slightly bowed or rounded shape as shown in the figures. Alternatively, distal end 70 may be in the form of a straight edge. The distal end 70 may also include a protrusion or other projection in alternative embodiments of the present invention.

[0028]The second major end flap 38 includes the aperture 50 defined therethrough, corresponding to tab 48 as explained in greater detail below. Aperture 50 can include first and second opposing edges 73 and 74, wherein edge 74 may serve as a locking edge, as described herein. As explained above, aperture 50 may be in the form of a slot, slit, notch or other similar opening. The aperture 50 need only be wide enough to partially receive tab 48; however, aperture 50 may have a width wider than that of tab 48. A peripheral shape of the locking edge 74 may generally correspond to a peripheral shape of the distal edge 70 of tab 48 in order to better facilitate engagement between locking edge 74 and distal edge 70 when locking the tab closure 12.

[0029]As shown in FIG. 1, when end construction 31 of container 10 is being closed, the minor flaps 32 and 34 are first folded inwardly. However, in some embodiments of the present invention, container 10 in constructed without minor end flaps 32 and 34. As depicted in FIG. 2, the first major end flap 36 may be folded inwardly into a folded orientation over the minor end flaps 32 and 34. The tab 48 may remain in a generally upright and unlocked orientation when first major end flap 36 placed in the folded orientation. If tab 48 is cut from the first major end flap 36, a resulting tab void 68 with a void edge 69 is defined in the first major end flap 36. In an alternative embodiment, where tab 48 is attached to first major end flap 36 rather than cut out from first major end flap 36, an overlapping zone with an overlapping zone edge serves as an equivalent to the void 68 and the void edge 69.

[0030]As illustrated in FIG. 3, after the minor end flaps 32 and 34 and the first major end flap 36 are all placed in the folded orientation, the second major end flap 38 can then be folded inwardly into a folded orientation to a position overlying the first major end flap 36. After all of the end flaps 32, 34, 36, and 38 have been placed into the folded orientation, the end construction 31 of container 10 is in a closed orientation. In one embodiment, second major end flap 38 has a length from its end flap fold line 46 to its edge 58 that is substantially the same distance between front panel 14 and rear panel 16. In such an embodiment, second major end flap 38 substantially overlaps first major end flap 36 when both are folded inward into their respective folded orientations. As also illustrated in FIG. 3, the tab 48 may remain generally upright and in its unlocked orientation when second major end flap 38 is folded inward and over first major end flap 36.

[0031]As explained above, tab 48 can project from tab fold line 66 and has a distal end 70. As illustrated in FIG. 3, tab 48 has a length D1, which is the distance between the tab fold line 66 and distal end 70. The length of tab 48, or D1, corresponds to the length of the tab void 68, which is the distance between tab fold line 66 and void edge 69. When the second major end flap 38 is folded inwardly into the folded orientation, the aperture 50 defined therein generally overlies the void 68 defined in the first major end flap 36. The aperture 50 may be of any suitable size and shape, and in one embodiment, has a size and shape generally similar to that of the void 68 resulting from tab 48. As demonstrated in FIG. 3, aperture 50 may be positioned within second major end flap 38 such that a distance D2 is defined between the tab fold line 66 and aperture locking edge 74 when second major end flap 38 is placed into a folded orientation. Distance D2 may be slightly less than distance D1. As a result, the locking edge 74 of aperture 50 may slightly overlap the void edge 69 when both first major end flap 36 and second major end flap 38 are placed their folded orientations.

[0032]In order to place end construction 31 of the container 10 into a locked position, a user may fold or rotate the tab 48 from an unlocked orientation downward toward the aperture 50, as represented by arrow 82 in FIG. 3, and push the tab 48 through the aperture 50, as shown in FIG. 4, placing the tab 48 into the locked orientation and the end construction 31 into a locked position. The distal end 70 of the tab 48 becomes snappingly engaged or tucked underneath the locking edge 74 of the aperture 50. When the length D1 of the tab 48 is slightly greater than the distance D2 defined between the tab's fold line 66 and the aperture locking edge 74, engagement between the locking edge 74 and the tab's distal end 70 occurs. This engagement holds and locks the tab 48 underneath second major end flap 38 and locking edge 74. When the tab 48 is pushed into the aperture 50 to create a locking engagement, either one or both of the tab 48 and second major end panel 38 may become momentarily slightly bowed or deformed inwardly in order to allow the distal end 70 of the tab 48 to pass by the locking edge 74 of the aperture 50. Once the user releases pressure from the tab 48, the tab 48 and second major end panel 38 may return to their original shape such that the distal end 70 of the tab 48 is retained underneath the locking edge 74 of the aperture 50. In one embodiment, the tab 48 acts as a strap overlying at least a portion 84 of the second major end flap 38 to hold the flap 38 in a folded orientation. The second major end flap 38 in turn holds the first major end flap 36 in a folded orientation, which in turn holds the minor end flaps 32 and 34 in a folded orientation.

[0033]When a user desires to open the container 10, the user disengages the tab 48 from the aperture 50. To do this, the user may place the pad of a finger or thumb on the tab 48 and slide or deflect the tab 48 in a direction represented by arrow 76 (see FIG. 4), for example laterally outwardly, in order to disengage the tab's distal end 70 from the aperture's locking edge 74. As best depicted in FIG. 5, tab extension cuts 72 of the tab cut line 64 forming the tab 48 may extend beyond the tab's fold line 66 into the front panel 14 in order to facilitate the tab 48 being slid in the direction of arrow 76. Alternatively, the user may place a finger nail, or suitable alternative, under the tab 48 to deflect the tab 48 away from the second major end flap 38, as represented by arrow 78 (see FIG. 4), in order to disengage the tab's distal end 70 from the aperture's locking edge 74.

[0034]As shown in FIG. 5, the carton 10 can be constructed from a flat blank 80 of material that may be formed of paperboard or other suitable material as described above. A plurality of blanks 80 may be cut (e.g., die cut) from a larger sheet or roll of material. The tab cut line 64 and extension cuts 72 forming the tab 48 and the cut forming the aperture 50 may be simultaneous made at the time the blank 80 is cut from the sheet or roll of material.

[0035]From the foregoing, it will be seen that this invention is one well adapted to attain all the ends and objects hereinabove set forth together with other advantages which are obvious and which are inherent to the structure. It will be understood that certain features and sub combinations are of utility and may be employed without reference to other features and sub combinations. This is contemplated by and is within the scope of the claims. Since many possible embodiments of the invention may be made without departing from the scope thereof, it is also to be understood that all matters herein set forth or shown in the accompanying drawings are to be interpreted as illustrative and not limiting.

[0036]The constructions described above and illustrated in the drawings are presented by way of example only and are not intended to limit the concepts and principles of the present invention. Thus, there has been shown and described several embodiments of a novel invention. As is evident from the foregoing description, certain aspects of the present invention are not limited by the particular details of the examples illustrated herein, and it is therefore contemplated that other modifications and applications, or equivalents thereof, will occur to those skilled in the art. The terms “having” and “including” and similar terms as used in the foregoing specification are used in the sense of “optional” or “may include” and not as “required”. Many changes, modifications, variations and other uses and applications of the present construction will, however, become apparent to those skilled in the art after considering the specification and the accompanying drawings. All such changes, modifications, variations and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by the invention which is limited only by the claims which follow.