EP2697136A1

EP2697136A1 - Panel interlocking arrangement

Info

Publication number: EP2697136A1
Application number: EP12714195.0A
Authority: EP
Inventors: George Papasotiriou
Original assignee: Meadwestvaco Packaging Systems LLC
Current assignee: WestRock Packaging Systems LLC
Priority date: 2011-04-15
Filing date: 2012-04-07
Publication date: 2014-02-19
Also published as: CA2833263A1; ZA201308536B; JP2014514219A; TW201302561A; KR20130140878A; MX2013011999A; RU2013150789A; BR112013026604A2; WO2012141986A1; CN103648924A; AU2012243041A1

Abstract

A panel interlocking arrangement secures together a first panel (146) and second panel (148) in an overlapping relationship. The arrangement includes a female locking tab (F) formed in the first panel and a male locking tab (M) formed in the second panel. The female locking tab is displaceable to define a first opening (O) in the first panel for receiving both the male and female locking tabs. The female locking tab includes a neck section (220) by which the female locking tab is connected to the first panel, and a head section (222. 224) foldably connected to the neck section by a fold line (228). The male locking tab is displaceable to define a second opening in the second panel for receiving the female locking tab.

Description

PANEL INTERLOCKING ARRANGEMENT

FIELD OF THE INVENTION

The present invention relates generally to cartons or cartons, and specifically, to a panel interlocking arrangement for ensuring a rigid connection between panels secured together in an overlapping arrangement.

BACKGROUND

Wrap-around cartons and hand-pack top loaded cartons are known, and have been long used as efficient, attractive, and convenient secondary packaging for holding, storing, and carrying multiple articles. For example, such cartons and cartons are useful for grouping and carrying multiple beverage containers while exposing the beverage containers for visibility and economy of material use. Wrap-around cartons and top-loaded cartons are typically top gripping, that is, they can be lifted from above using a handle component. The carton or carton will frequently include interlocking assemblies that mechanically lock overlapping panels together, as the lower wall of the carton typically must bear the weight of the contents without reinforcement. Accordingly, the panels of the carton must be securely and reliably locked together to prevent separation of the overlapping panels of the bottom wall, or undesirable shifting of the container group as the carton or carton is being carried.

Many panel interlocking arrangements have been implemented in the art, although most fail to thoroughly restrict relative motion between the overlapping panels. In fact, some arrangements successfully limit movement of the panels away from one another along a notional plane defined between the overlapping panels, but fail to rigidly restrict movement of the panels toward one another along the notional plane or away from one another in a direction normal to the notional plane, and also fail to prevent lateral motion between the panels. SUMMARY OF THE INVENTION

The shortcomings of the prior art are addressed by the various aspects of the present invention, which provides a panel interlocking arrangement in which two panels are secured together in an overlapping arrangement. The panel interlocking

arrangement provides a very rigid connection between the two panels, in that it restrains the two panels from moving away from each other along a notional plane defined between the overlapped panels, it restrains the panels from moving toward each other along the notional plane, it restrains the panels from moving laterally with respect to one another, and it restrains the panels from moving away from each other in a direction that is normal to the notional plane defined between the panels.

Specifically, the invention in one aspect provides a panel interlocking

arrangement that comprises a pair of first and second panels disposed in an

overlapping relationship and a pair of male and female locking tabs that cooperate with one another to secure the first and second panels together in the overlapping

relationship. The female locking tab is struck from the first panel and is foldably connected at its proximal end edge to the first panel such that a first opening is defined in the first panel when the female locking tab is folded out of a plane of the first panel. The female locking tab includes a neck section and a head section hingedly connected to the neck section by a fold line. The neck section extends between the fold line and the proximal end edge of the female locking tab whereas the head section extends between the fold line and a distal end edge of the female locking tab. The male locking tab is struck from the second panel and is foldably connected at its proximal end edge to the second panel such that a second opening is defined in the second panel when the male locking tab is folded out of a plane of the second panel. The proximal end edge of the male locking tab is disposed substantially parallel to a free edge of the second panel with the second opening interposed therebetween. The first and second panels are arranged such that the first and second openings are in substantial alignment and such that part of the second panel along its free edge is disposed between the first opening and the neck section of the female locking tab. The male locking tab is folded out of the plane of the second panel and received in the first opening of the first panel to take a folded position. The female locking tab is folded along the fold line such that the head section of the female locking tab is received in the first and second openings and is disposed at a retaining position where the head section is in a mutually bracing engagement with the male locking tab to retain the male and female locking tabs in the folded and retaining positions respectively.

In a preferred embodiment, the distal end edges of the male and female locking tabs may be disposed over one side of the first panel. In another preferred embodiment, the free edge of the second panel may be disposed in abutment on the female locking tab such that the free edge of the second panel is in substantial alignment with the proximal end edge of the female locking tab.

In another preferred embodiment, the part of the second panel along the free edge of the second panel may include a portion between the second opening and the free edge of the second panel.

In still another preferred embodiment, the first opening of the first panel may have an inner end to which the proximal end edge of the female locking tab is foldably connected, and the male locking tab in the folded position may be in engagement with an outer end of the first opening opposite to the inner end of the first opening.

In a further preferred embodiment, the second opening of the second panel may have an inner end to which the proximal end edge of the male locking tab is foldably connected, and the head section of the female locking tab in the retaining position may be in engagement with an outer end of the second opening opposite to the inner end of the second opening.

In a further preferred embodiment, the head section of the female locking tab in the retaining position may brace against the male locking tab. In such an embodiment, the male locking tab may lean against the distal end edge of the head section of the female locking tab.

In a further preferred embodiment, the male locking tab in the folded position may brace against the head section of the female locking tab. In such an embodiment, the head section of the female locking tab may lean against the distal end edge of the male locking tab.

In another preferred embodiment, at least one of the male and female locking tabs may include a shoulder section that is substantially wider than the remainder of the at least one of the male and female locking tab.

In a further preferred embodiment, one of the male and female locking tabs may include an extension tab projecting from the distal end edge of the one of the male and female locking tabs, and the other of the male and female locking tabs may be provided with complementary cutout for receiving the extension tab.

The invention in a second aspect provides a blank for forming a panel interlocking arrangement. The blank comprises a pair of first and second panels that are to be disposed in an overlapping relationship when the arrangement is formed; and a pair of male and female locking tabs for cooperation with one another to secure the first and second panels together in the overlapping relationship. The female locking tab is struck from the first panel and is foldably connected at its proximal end edge to the first panel such that a first opening for receiving both the male and female locking tabs is defined in the first panel when the female locking tab is folded out of a plane of the first panel. The female locking tab includes a neck section and a head section hingedly connected to the neck section by a fold line. The neck section extends between the fold line and the proximal end edge of the female locking tab whereas the head section extends between the fold line and the distal end edge of the female locking tab. The male locking tab is struck from the second panel and is foldably connected at its proximal end edge to the second panel such that a second opening for receiving the female locking tab is defined in the second panel when the male locking tab is folded out of a plane of the second panel. The proximal end edge of the male locking tab is disposed substantially parallel to a free edge of the second panel with the second opening interposed therebetween.

The invention in a third aspect provides a carton that includes the

aforementioned panel interlocking arrangement.

The foregoing has broadly outlined some of the aspects and features of the present invention, which should be construed to be merely illustrative of various potential applications of the invention. Other beneficial results can be obtained by applying the disclosed information in a different manner or by modifying the disclosed embodiments. Accordingly, other aspects and a more comprehensive understanding of the invention may be obtained by referring to the detailed description of the exemplary embodiments taken in conjunction with the accompanying drawings, in addition to the scope of the invention defined by the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of an exemplary blank for forming a carton that includes the panel-interlocking arrangement of the present invention.

FIG.2 is an enlarged view of the components of the panel-interlocking

arrangement. FIG.3 is a perspective view of the exemplary carton formed from the blank of

FIG. 1.

FIGs.4-14 are enlarged partial views showing an exemplary method for operating the panel-interlocking arrangement. FIG. 15 is an enlarged partial view of the panel-interlocking arrangement in operative condition.

FIG. 16 is a bottom view of the carton of FIG. 2, with two pairs of male and female locking tabs in accordance with the present invention securing together the bottom panels of the carton.

FIGs. 17-21 are enlarged partial views showing another exemplary method for operating the panel-interlocking arrangement.

FIGs. 22-31 are partial perspective views showing the folding of bottom panels of the carton of FIG. 2, to illustrate yet another exemplary method for operating the panel- interlocking arrangement.

DETAILED DESCRIPTION

As required, detailed embodiments of the present invention are disclosed herein. It must be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms, and combinations thereof. As used herein, the word "exemplary" is used expansively to refer to

embodiments that serve as illustrations, specimens, models, or patterns. The figures are not necessarily to scale and some features may be exaggerated or minimized to show details of particular components. In other instances, well-known components, systems, materials, or methods have not been described in detail in order to avoid obscuring the present invention. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention.

Referring now to the drawings, wherein like numerals indicate like elements throughout the several views, the drawings illustrate certain of the various aspects of exemplary embodiments of a carton. In the embodiments detailed herein, the term carton refers, for the non-limiting purpose of illustrating the various features of the invention, to a container for engaging, carrying, and dispensing articles, such as clear plastic bottles. However, it is contemplated that the teachings of the invention can be applied to various containers, which may or may not be tapered and/or cylindrical.

Other exemplary articles include metallic or glass bottles, aluminum cans, bowling pins, candles, and the like.

For purposes of teaching the various aspects of the present invention, and not of limitation, the panel interlocking arrangement L will be described in the context of an exemplary top-loaded carton style package for multiple cylindrical cans or bottles. The male locking tab M and female locking tab F (best shown in FIG. 2) of each panel interlocking arrangement L (best shown in FIG. 16) is defined in a blank 10, which may be made from a single sheet of suitable substrate in which a number of hingedly connected panels are defined. The inside surface of the blank 10 is shown in FIG. 1.

With reference to FIG. 1, the exemplary blank 10 includes a series of panels that will define the perimeter of the carton 20, including an end flap 100, a first side panel 102 and a second side panel 104, a first end panel 106 and a second end panel 108. The upper edges of these perimeter panels define the top edge 110 of the carrying compartment of the carton 20. The lower edges of these perimeter panels define the bottom edge 112 of the carrying compartment o the carton 20.

The end flap 100 is hingedly connected along fold line 114 to the first side panel 102, the first side panel 102 is hingedly connected along fold line 116 to the first end panel 106, the first end panel 106 is hingedly connected along fold line 118 to the second side panel 104, the second side panel 104 is hingedly connected along fold line 120 to the second end panel 108. The carton 20 (FIG. 3) includes a composite handle panel H, which is formed from a number of other panels defined in the blank 10. Specifically, the blank 10 includes a center panel 122 with finger-hold apertures A, a handle reinforcing panel 124 with complementary finger-hold apertures A, and a divider panel 126 that may also include one or more finger-hold apertures A. The center panel 112 is hingedly connected along fold line 128 to the handle reinforcing panel 124, and also is hingedly connected along fold line 130 to the end flap 100. The center panel 122 is hingedly connected along fold line 132 at its bottom edge to the divider panel 126. An edge flap 134 is hingedly connected along fold line 136 to the center panel 122, and is used to secure the center panel 122 to an end panel 106 when the carton 20 is erected, as will be described in more detail below.

A number of divider strips are hinged connected to and at least partially struck from the center panel 122 and the divider panel 126. Specifically, a first divider strip 138 and a second divider strip 140 are hingedly connected to the center panel 122 along respective fold lines 139 and 141, each divider strip 138 and 140 being spaced equally apart from one another and from the fold lines 136 and 130 that define the side edges of the center panel 122. The first divider strip 138 extends from the fold line 139 toward the second divider strip 140 and extends across the fold line 141 that connects the second divider strip 140 to the center panel 122, thereby defining a tab T at its distal edge. The second divider strip 140 extends from the fold line 141 toward the end flap 100 and extends onto the end flap 100 by crossing the fold line 130, thereby defining tab T at its distal edge. The blank 10 also includes a third divider strip 142 hingedly connected along fold line 143 to the divider panel 126, and a fourth divider strip 144 hingedly connected along fold line 145 to the divider panel 126. A tab T is defined at the distal edge of the third divider strip 142. The fourth divider strip 144 extends from the fold line 145 and toward the third divider strip 142 and extends across the fold line 143 to connects the third divider strip 144 to the divider panel 126, thereby defining a tab T.

The blank 10 include a first bottom panel 146 and a second bottom panel 148 that are hingedly connected along respective fold lines 150 and 152 that extend along the bottom edge 112 of the carton 20. The first bottom panel 146 and the second bottom panel 148 are configured to be secured together in an overlapping fashion using two panel interlocking arrangement Ls in accordance with the present invention. The female locking tabs F of two panel interlocking arrangements L are formed in the first bottom panel 146 proximate the free edge 154, and the complementary male locking tabs M of the two panel interlocking arrangements L are formed in the second bottom panel 148 proximate the free edge 156. Those skilled in the art will readily appreciate that any number of panel interlocking arrangements L may be desirable, depending for example upon the characteristics of the substrate from which the carton 20 is formed, the characteristics of the articles that are to be carried, and the structural design of the carton 20. The carton 20 shown in FIG. 3 is designed to carry articles such cans or bottles in a 2x3 configuration and the panel interlocking arrangements L may secure the bottom panels 146, 148 together alone or in combination with adhesive, so the number and placement of panel interlocking arrangements L is a design choice selected accordingly. As will be described in more detail, the placement of the panel interlocking arrangements L may be selected to cooperate with the placement of the articles and divider strips in the carton 20 to prevent failure of the panel interlocking arrangements L.

Referring now to FIG. 2, the locking tabs F, M of the panel interlocking

arrangements L are now described in greater detail. More specifically, the male locking tab M defines a complementary opening in the second bottom panel 148 when displaced from the notional plane of the second bottom panel 148. The male locking tab M is segmented to include a neck section 202, a shoulder section 204 and a tongue 206, although certain of the segments are substantially continuous to one another, and certain other segments are hingedly connected along fold lines, or are simply foldable with respect to one another without being joined by distinct fold lines. In the

embodiment shown, the neck section 202 is a partially separated section continuous to the second bottom panel 148, and is hingedly connected to the shoulder section 204 along fold line 208, which is interrupted by a substantially semi-circular first arcuate severance line (or cut line) 210 that is centered along and extends across the fold line 208 and onto the shoulder section 204. In some embodiments of the invention, the neck section 202 may be omitted so that the shoulder section 204 is connected to the second bottom panel 148 directly or with a fold line therebetween. The shoulder section 204 is substantially wider than the neck section 202, having convexly rounded "wings" defining the contours of its side edges. The tongue 206 defines the distal end of the male locking tab M, and is substantially narrower than the shoulder section 204, but may have approximately the same width as the neck section 202. Accordingly, the width W1 of the shoulder section 204 is greater than the width W2 of the neck section 202 and the width W3 of the tongue 206. The width W2 of the neck section 202 may be substantially equivalent to the width W3 of the tongue 206. The tongue 206 includes a substantially semi-circular second convex retention tab 212 formed along the distal end edge 214 of the male locking tab M.

The female locking tab F defines a complementary opening in the first bottom panel 146. The female locking tab F is also segmented to include a neck section 220, a shoulder section 222 with curved side edges, and a bracing section 224, although certain of the segments are substantially continuous to one another, and certain other segments are hingedly connected along fold lines, or are simply foldable with respect to one another without being joined by distinctly defined and/or pre-scored fold lines. In the embodiment shown, the neck section 220 is hingedly connected to the first bottom panel 146 along a fold line 226, and is hingedly connected to the shoulder section 222 along a fold line 228. The fold line 228 is interrupted by a substantially semi-circular convex retention tab 230 that is centered along the fold line 228, and extends onto the shoulder section 222. The shoulder section 222 is continuous with the bracing section 224 that defines the distal end edge of the female locking tab F. The bracing section 224 includes a substantially semi-circular concave cutout 231 along the distal end edge 236 of the female locking tab F, the concave cutout 231 defining a corresponding substantially semi-circular convex retention tab 232 in the first bottom panel 146. The bracing section 224 and the shoulder section 222 will sometimes referred to collectively as a "head section". The bracing section 224 defines the distal end of the female locking tab F, and is substantially narrower than the shoulder section 222, but may have approximately the same width as the neck section 220. Accordingly, the width W4 of the shoulder section 222 is greater than the width W5 of the neck section 220 and the width W6 of the bracing section 224. The width W5 of the neck section 220 may be substantially equivalent to the width W6 of the bracing section 224. The bracing section 224 includes a substantially semi-circular second concave cut-out 231 formed along the distal end edge 236 of the female locking tab F.

Those skilled in the art will recognize that the convex retention tabs 210, 212, 232 and concave cut-outs 231 are substantially semi-circular, but that alternate shapes may function in the same manner. Similarly, the wing-like curved sides of the shoulder sections 204, 222 may have alternate contours consistent with the teachings of the invention.

To erect the carton 20, an exemplary method for folding the blank 10 is as follows, although that the folding operations shown and described may be exaggerated of purposes of teaching. The inside surface of the divider panel 126 is folded into face contacting relation to the inside surface of the center panel 122, and may be secured in that arrangement using a suitable adhesive. The handle reinforcing panel 124 is folded along the fold line 128 to place its inside surface in face contacting relation to the outside surface of the divider panel 126 and to a still exposed portion of the inside surface of the central panel 122. The central panel 122 and the handle reinforcing panel 124 may be secured in place using a suitable adhesive. In any case, application of adhesive to the surfaces of the divider strips 138, 140, 142, 144 is preferably avoided so that they can be deployed. By securing the central panel 122 to the handle reinforcing panel 124 with the divider panel 126 partially disposed therebetween, a composite handle panel H is formed. The finger-hold apertures A in each of these panels are placed in substantial alignment to form two openings in the handle panel H for ease of carrying the carton 20. Those skilled in the art will readily appreciate that there may be only a single opening in the handle panel H or more than two openings may be included. Alternately, other carrying means may be employed, including but not limited to, external straps, T-bars, fold-over sections, and the like. Continuing with the exemplary method for erecting the carton 20, once the handle panel is formed, the outer perimeter P (FIG. 16) of the carton 20 is constructed. The blank 10 is folded out of the plane of FIG. 1 along the fold lines 114, 116, 118, 120 such that the end flap 100, first side panel 102, first end panel 106, second side panel 104, and second end panel 108 are substantially at right angles with respect to one another, with a portion of the inside surface of the second end panel 108 being in face contacting relation to the outside surface of the end flap 100. In this fashion, the first side panel 102, first end panel 106, second side panel 104, and second end panel 108 define the outer perimeter, top edge 110 and bottom edge 112 of the carton 20, and the outer perimeter P is secured by affixing the end flap 100 to the inside surface of the second end panel 108. The composite handle panel H is hingedly connected to the end flap 100 and is now disposed inside of the outer perimeter P of the carton 20. The free side edge of the composite handle panel H is secured proximate to the center of the first end panel 106 using the edge flap 136. Thusly, the composite handle panel H bisects the interior of the carton 20, extending between the respective centers of the first end panel 106 and the second end panel 108, and spaced apart from the first side panel 102 and the second side panel 104. Either before or after securing the first bottom panel 146 to the second bottom panel 148 using the panel interlocking arrangements L of the present invention, the divider strips 138, 140 are folded toward the second side panel 104 and secured using the tabs T at their distal ends, and the divider strips 142, 144 are folded toward the first side panel 102 and secured using the tabs T at their distal ends. Before securing the first side panel 102 and the second side panel 104 and the divider strips 138, 140, 142, 144, the carton 20 can be flattened for storage or shipping, for example, to another facility for final erection and loading with articles.

Finally, bottom of the carton 20 is formed by securing the first bottom panel 146 to the second bottom panel 148 in an overlapping arrangement, as shown in FIG. 16. The first bottom panel 146 is folded upward along fold line 150 to a right angle with respect to the first side panel 102, and the second bottom panel 148 is folded upward along fold line 152 to a right angle with respect to the second side panel 104, thereby bringing them substantially into the same horizontal plane, as shown in FIG. 4, with their respective free edges 154, 156 proximate one another.

The overlapping arrangement of the first bottom panel 146 to the second bottom panel 148 is secured using the panel interlocking arrangements L of the present invention, as is demonstrated in the series of partial perspective and side views in FIGs. 4-15. For simplicity of teaching, each view in this series shows various stages of engagement of the components of one of the panel interlocking arrangements L that secure the bottom of the carton 20, and may exaggerate the relative positions of the first bottom panel 146 and the second bottom panel 148 or their respective components. FIGs. 4, 5, 8, 9, 11 and 13 are partial perspective views from a hypothetical vantage point inside of the carton 20, FIG. 15 is a partial perspective view from a hypothetical vantage point outside of the carton 20, and FIGs. 6, 7, 10, 12 and 14 are partial side views.

Referring now to FIG. 4, male locking tab and female locking tab F are initially coplanar with the first bottom panel 146 and the second bottom panel 148. The female locking tab F is then folded outwardly along the fold line 226 that is located at the proximal end edge of the female locking tab F, as shown in FIG. 5 in which a first opening O is revealed for receiving the male locking tab M. The first opening O extends from the fold line 226 to an outer end 238. The elevation of the first bottom panel 146 is slightly higher than that of the second bottom panel 148, as shown in FIG. 6, and the free edge 156 of the second bottom panel 148 is brought into abutting contact with the neck section 220 at the base (and near the proximal end edge) of the female locking tab F and into substantial alignment with the fold line 226, as shown in FIGs. 7 and 8. In FIG. 8 the male locking tab M and a part of the second bottom panel 148 (the part extending between the male locking tab M and the free edge 156) are visible through the opening O, as they are still coplanar and in face contacting relation to the outside surface of the first bottom panel 146, and the fold line 208 is substantially aligned with the outer end 238 of the first opening O, proximate the free edge 154 of the first bottom panel 146. With reference to FIGs. 9 and 10, the shoulder section 204 of the male locking tab is folded inwardly along the fold line 208, bringing the shoulder section 204 and tongue 206 through the first opening O. The outer end 238 of the first opening O is narrower than the shoulder section 204, so the wing-like convexly curved side edges of the shoulder section 204 are thereby lodged against the edges of the first opening O. As the shoulder section 204 of the male locking tab M is folded out of the plane of the second bottom panel 148, a second opening (shown in FIG. 9 as being substantially vertically aligned with the first opening O) is revealed in the second bottom panel 148 while the semi-circular convex retention tab 232 in the first bottom panel 146 overlies and is in substantial alignment with the arcuate severance line 210. The semi- circular convex retention tab 232 and the protrusion defined by the arcuate severance line 210 engage the cavity 240 that is defined in the male locking tab M when it is folded upward through the opening O.

Referring now to FIG. 12, the female locking tab F is folded along fold line 226 under the free edge 156 of the second bottom panel 148. By this means, the neck section 220 of the female locking tab F is brought into face contacting relationship with the lower or outside surface of the aforementioned visible "part" of the second bottom panel 148 such that the part of the second bottom panel 148 is interposed between the first opening O and the neck section 220 of the female locking tab F. Then, as shown in FIGs. 13 and 14, the head section 222, 224 of the female locking tab F is folded upward along the fold line 228 about the outer end 214 of the second opening in the second bottom panel 148. By this means, the head section 222, 224 of the female locking tab F is inserted into and thereby received in both the first and second openings such that the respective distal end edges 214, 236 of the male and female locking tabs M, F are disposed over the upper or inside surface of the first bottom panel 146. This condition is best shown in FIGs. 13 and 14 in which the male locking tab M is illustrated as being in its folded position whereas the female locking tab F is illustrated in its retaining position. When the male and female locking tabs M, F are folded and retaining positions respectively, the male and female locking tabs M, F are in their mutually bracing position in which they prevent each other from being folded back to their respective initial positions where they lie in the respective planes of the second and first bottom panels 148, 146 respectively. When in the mutually bracing position, the head section 222, 224 of the female locking tab F may brace against male locking tab M so that the male locking tab M leans against the distal end edge 236 of the female locking tab F. In an alternative mutually bracing position, the male locking tab M may brace against the head section 222, 224 of the female locking tab F so that the head section 222, 224 of the female locking tab F leans against the distal end edge 214 of the male locking tab M. In the embodiment illustrated in FIGs. 13 and 14, however, the male and female locking tabs M, F are in another alternative bracing engagement in which the concave cut-out 231 in the distal end edge 236 of the female locking tab F is brought into engagement with the convex locking tab 212 protruding from the distal end edge 214 of the male locking tab M. FIG. 15 is a view from a hypothetical vantage point below the underside of the carton 20, showing the male locking tab M and the female locking tab F so engaged. In this state, the panel interlocking arrangement L is fully engaged.

It should be noted that the female locking tab F need not be folded into the 90 degree position shown in FIGs. 9 and 10. FIGs. 17 illustrate an alternative method in which the female locking tab F is pushed out of the plane of the first bottom panel 146 just enough to allow the free edge 156 of the second bottom panel 148 to slide over the female locking tab F and under the free edge 154 of the first bottom panel 146 to bring the male locking tab M into registry of the opening O. Then, in a single motion, both the female locking tab F and the male locking tab M can be forced up through the opening O, such as by a single punching action on automatic packaging equipment. Referring particularly to FIGs. 19-21 , the punching action is illustrated by applying a force

(illustrated by an arrow) beneath the female locking tab F that drives it up and through the opening O, where the female locking tab F impacts the male locking tab M, which yields itself to the female locking tab F and is thrust upward as shown in FIG. 20. Once the female locking tab F is fully extended, the concave cut-out 231 in the distal end edge 236 of the female locking tab F is brought upward to engage the convex locking tab 212 along the distal end edge 214 of the male locking tab M, as shown in FIG. 21. Another exemplary method is illustrated as a series of steps as shown in the partial perspective views of FIGs. 22-31. When implementing the folding operations described above in connection with the carton 20, the first bottom panel 146 and second bottom panel 148 will likely be disposed initially as shown in FIG. 22, extending downward from the first side panel 102 and the second side panel 104, respectively (neither side panel is shown in FIGs. 22-31 ). In FIG. 23, automatic packaging equipment, such as a punch or folding wheel, folds the female locking tab F out of the plane of the first bottom panel 146, thereby defining the opening O. Then, in FIG. 24, the first bottom panel 146 is folded upward toward the interior of the carton 20 (not shown). As or after the first bottom panel 146 moves into the substantially horizontal position shown in FIG. 25, the second bottom panel 148 is folded upward as shown in FIG. 26 to underlie the first bottom panel 146 in a face contacting arrangement, as shown in FIG. 27, and with the male locking tab M in registry with the opening O. From here, the method proceeds as shown in FIGs. 19-21 , as the female locking tab F is folded upward to underlie the male locking tab M. Returning to FIGs. 28 and 29, as a force is applied beneath the female locking tab F, it drives the male locking tab M through the opening O, thereby bringing the tongue 206 and shoulder section 204 of the male locking tab M through the opening O. In FIGs. 29 and 30, the male locking tab continues to be forced upward through the opening O until the female locking tab F has also been driven through. As described above, the female locking tab F and male locking tab M may brace one another and engage one another along the cut-out 232 and the convex retention tab 212.

The present invention has been illustrated in relation to particular embodiments that are intended in all respects to be illustrative rather than restrictive. Those skilled in the art will recognize that the present invention is capable of many modifications and variations without departing from the scope of the invention. For example, as used herein, directional references such as top, base, bottom, end, side, inner, outer, upper, middle, lower, front, and rear do not limit the respective walls of the carton to such orientation, but merely serve to distinguish these walls from one another. Any reference to hinged connection should not be construed as necessarily referring to a junction including a single hinge only; indeed, it is envisaged that hinged connection can be formed from one or more potentially disparate means for hingedly connecting materials.

The above-described embodiments are merely exemplary illustrations of implementations set forth for a clear understanding of the principles of the invention. Variations, modifications, and combinations may be made to the above-described embodiments without departing from the scope of the claims. All such variations, modifications, and combinations are included herein by the scope of this disclosure and the following claims.

Claims

1. A panel interlocking arrangement comprising:

a pair of first and second panels disposed in an overlapping relationship; and

a pair of male and female locking tabs cooperating with one another to secure the first and second panels together in the overlapping relationship,

wherein the female locking tab is struck from the first panel and is foldably connected at a proximal end edge thereof to the first panel such that a first opening is defined in the first panel when the female locking tab is folded out of a plane of the first panel, the female locking tab including a neck section and a head section hingedly connected to the neck section by a fold line, the neck section extending between the fold line and the proximal end edge of the female locking tab, the head section extending between the fold line and a distal end edge of the female locking tab,

wherein the male locking tab is struck from the second panel and is foldably connected at a proximal end edge thereof to the second panel such that a second opening is defined in the second panel when the male locking tab is folded out of a plane of the second panel, the proximal end edge of the male locking tab being disposed substantially parallel to a free edge of the second panel with the second opening interposed therebetween,

wherein the first and second panel are arranged such that the first and second openings are in substantial alignment and such that part of the second panel along the free edge of the second panel is disposed between the first opening and the neck section of the female locking tab,

wherein the male locking tab is folded out of the plane of the second panel and received in the first opening of the first panel to take a folded position, and wherein the female locking tab is folded along the fold line such that the head section of the female locking tab is received in the first and second openings and is disposed at a retaining position where the head section is in a mutually bracing engagement with the male locking tab to retain the male and female locking tabs in the folded and retaining positions respectively.

2. The panel interlocking arrangement of claim 1 , wherein the distal end edge of the female locking tab is opposed to the proximal end edge thereof, the male locking tab has a distal end edge opposed to the proximal end edge of the male locking tab, and the distal end edges of the male and female locking tabs are disposed over one side of the first panel.

3. The panel interlocking arrangement of claim 1 , wherein the free edge of the second panel is disposed in abutment on the female locking tab such that the free edge of the second panel is in substantial alignment with the proximal end edge of the female locking tab.

4. The panel interlocking arrangement of claim 1 , wherein the part of the second panel along the free edge of the second panel comprises a portion between the second opening and the free edge of the second panel.

5. The panel interlocking arrangement of claim 1 , wherein the first opening of the first panel has an inner end to which the proximal end edge of the female locking tab is foldably connected, and wherein the male locking tab in the folded position is in engagement with an outer end of the first opening opposite to the inner end of the first opening.

6. The panel interlocking arrangement of claim 1 , wherein the second opening of the second panel has an inner end to which the proximal end edge of the male locking tab is foldably connected, and wherein the head section of the female locking tab in the retaining position is in engagement with an outer end of the second opening opposite to the inner end of the second opening.

7. The panel interlocking arrangement of claim 2, wherein the head section of the female locking tab in the retaining position braces against the male locking tab.

8. The panel interlocking arrangement of claim 7, wherein the male locking tab leans against the distal end edge of the head section of the female locking tab.

9. The panel interlocking arrangement of claim 2, wherein the male locking tab in the folded position braces against the head section of the female locking tab.

10. The panel interlocking arrangement of claim 9, wherein the head section of the female locking tab leans against the distal end edge of the male locking tab.

11. The panel interlocking arrangement of claim 1 , wherein at least one of the male and female locking tabs comprises a shoulder section that is substantially wider than the remainder of the at least one of the male and female locking tab.

12. The panel interlocking arrangement of claim 2, wherein one of the male and female locking tabs comprises an extension tab projecting from the distal end edge of the one of the male and female locking tabs, and the other of the male and female locking tabs is provided with complementary cutout for receiving the extension tab.

13. A blank for forming a pane! interlocking arrangement, the blank comprising:

a pair of first and second panels that are to be disposed in an overlapping relationship when the arrangement is formed; and

a pair of male and female locking tabs for cooperation with one another to secure the first and second panels together in the overlapping relationship,

wherein the female locking tab is struck from the first panel and is foldaWy connected at a proximal end edge thereof to the first panel such that a first opening for receiving both the male and female locking tabs is defined in the first panel when the female locking tab is folded out of a plane of the first panel, the female locking tab including a neck section and a head section hingedly connected to the neck section by a fold line, the neck section extending between the fold line and the proximal end edge of the female locking tab, the head section extending between the fold line and a distal end edge of the female locking tab, and

wherein the male locking tab is struck from the second panel and is foldably connected at a proximal end edge thereof to the second panel such that a second opening for receiving the female locking tab is defined in the second panel when the male locking tab is folded out of a plane of the second panel, the proximal end edge of the male locking tab being disposed substantially parallel to a free edge of the second panel with the second opening interposed therebetween.

14. The panel interlocking arrangement of claim 13, wherein at least one of the male and female locking tabs comprises a shoulder section that is substantially wider than the remainder of the at least one of the male and female locking tab.

15. The panel interlocking arrangement of claim 13, wherein one of the male and female locking tabs comprises an extension tab projecting from a distal end edge of the one of the male and female locking tabs, and the other of the male and female locking tabs is provided with complementary cutout for receiving the extension tab.

16. A carton comprising:

a pair of first and second panels disposed in an overlapping relationship; and

17. The carton of claim 16, wherein the distal end edge of the female locking tab is opposed to the proximal end edge thereof, the male locking tab has a distal end edge opposed to the proximal end edge of the male locking tab, and the distal end edges of the male and female locking tabs are disposed over one side of the first panel.

18. The carton of claim 16, wherein the free edge of the second panel is disposed in abutment on the female locking tab such that the free edge of the second panel is in substantial alignment with the proximal end edge of the female locking tab.

19. The carton of claim 16, wherein the first opening of the first panel has an inner end to which the proximal end edge of the female locking tab is foldably connected, and wherein the male locking tab in the folded position is in engagement with an outer end of the first opening opposite to the inner end of the first opening.

20. The carton of claim 16, wherein the second opening of the second panel has an inner end to which the proximal end edge of the male locking tab is foldably connected, and wherein the head section of the female locking tab in the retaining position is in engagement with an outer end of the second opening opposite to the inner end of the second opening.