Box with an opening-resistant end

Abstract: A box with an opening-resistant end, comprising at least one foldable flap (14) positionable below the closed end, from said flap (14) there projecting two opposing hook-shaped teeth (19,20) inserted into apertures (16) provided in said end, to securely engage it and hinder its opening.

Description: This invention relates to a box with an end of high resistance to opening, and more particularly to a box with one or more closure bases or lids with which coupling teeth projecting from flaps lying below each lid interfere in order to substantially increase its resistance to opening. The patents US-A-4,890,789, EP-B-0318750 and DE-A-3826231 describe boxes provided with at least one base or lid with high resistance to opening. The lid for which high resistance to opening is required has a folded tab insertable into the box, to the side of one or more flaps projecting from certain main panels of the box and positioned below or within the lid under consideration (this structure is traditional to all boxes of this type), and is characterised in that in this tab there is provided a thin elongate slot into which (when the box is closed) there are inserted two hook-shaped or dovetail-shaped teeth projecting one from each of said flaps and arranged superposed one on the other within the closed box. When the lid is pulled to open it, it drags and raises said two teeth (which extend into said elongate slot in the lid tab) away from their rest position. As the teeth are rigid with the flaps, which are connected to the adjacent main panels of the box along folding lines inclined (generally perpendicular) to the folding line about which the lid can rotate, it follows that raising the two teeth (by the effect of the traction exerted on them by the lid which is to be opened) causes the two teeth to diverge and withdraw from each other within the slot in which they are inserted, to hence strongly hook on to the tab within which this slot is formed. The result is that the resistance to opening of the box lid is greatly increased by the retention action exerted on it by the teeth projecting from the flaps of the box. This does not prevent it being possible, using suitable care, to release the lid from the hook teeth of the flaps and hence open the box lid (or lids) and then reclose it (or them) without the previous opening being noticeable. The patents US-A-1,989,659 and US-A-3,578,154 describe boxes having at least one lid consisting of a closure panel from which there extends a tab separated from said panel by a folding line which is cut at its two ends to form two slots in which two flaps forming part of the box and folded below the closure panel become engaged (when the box is in its closed state). When an attempt is made to open the lid, said flaps retain the tab and oppose lid opening. However, if the box is slightly squeezed on its front and rear the flaps can be easily disengaged from the slots in the lid, which can then be opened and reclosed. US-A-5,207,374 and the corresponding EP-A-0 519 389 illustrate a box comprising a lid consisting of a closure panel from which there extends a foldable tab insertable into the box, in said tab there being provided two separate apertures extending from the folding line separating the tab from the adjacent closure panel, below which two separate non-superposable flaps projecting from two main lateral walls of the box become positioned (when the box is closed). From each flap there projects one (only one) hook-shaped tooth which is inserted into one of the two said apertures, to engage it and hence hinder the opening of the box lid. This construction however also suffers from the drawback that the base of the box can be opened fairly easily by deforming the closure panel firstly on one side and then on the other, so as to release firstly one and then the other hook-shaped tooth from the respective apertures. The main object of the present invention is to provide a box of the aforesaid type, in which the closure panel of the lid of the closed box is engaged in an extremely effective manner by hook-shaped teeth projecting from flaps positioned below said closure panel, so making it extremely difficult, if not almost impossible, to open said lid without damaging said teeth and that region of the lid which is engaged by them. A further object is to provide a box, the lid of which can be opened only after breaking or detaching at least one portion of the lid, hence making any fraudulent tampering of the box apparent. Such a box comprises: at least three adjacent main panels separated from each other by first folding lines formed in a punched sheet of flexible material; at least one closure panel for said box, said closure panel projecting from a first main panel and having a projecting tab, the closure panel being separated from said tab and from the adjacent main panel by second folding lines such that said tab is insertable into the box below at least one second main panel; at least two separate apertures formed by cuts provided in correspondence with the folding line between said tab and the respective closure panel, the first aperture being formed by a cut made at the end of said folding line and the second aperture being formed in the tab in proximity to the first aperture; at least one rotatable flap projecting from at least one third main panel, said flap being rotatable about a third folding line which separates it from said third panel and being positionable below the closure panel; coupling elements projecting from said flap and insertable into said apertures to retain said closure panel in its closed position; characterised in that said coupling elements consist of two hook-shaped teeth projecting from said flap and having their greatest width at their free end, the opposing sides of the two hook-shaped teeth and the intermediate flap edge between them defining a substantially dovetail-shaped free space with its maximum width at the edge of the flap, the free ends of the two hook-shaped teeth having a width less than that of the respective apertures through which they can extend and project to retain said tab with its respective closure panel in the closed position. The invention also relates to the punched sheet used for forming the aforesaid box. The structure and characteristics of the box will be more apparent from the description of some embodiments thereof given hereinafter by way of non-limiting example with reference to the accompanying drawings, in which: Figure 1 is a plan view of a punched cardboard sheet usable for forming a box: Figure 2 is a perspective view thereof with the box already assembled, but with its two ends open; Figure 3 shows a portion of the box with one of its ends closed, a part of the box having been omitted to clarify the cooperation between its various component parts; Figure 4 is analogous to Figure 3, but shows how the cooperating parts of the box engage each other on seeking to open its end; Figure 5 is a perspective view of the box with its end open and with one of its portions torn off by one of its end retention teeth; and Figures 6 and 7 are two partial plan views of two punched cardboard sheets usable to form boxes similar to those of Figures 1 to 5. The punched cardboard sheet shown in Figure 1 comprises four main panels 1, 2, 3, 4 and a fixing tab 5 which are separated from each other by first parallel folding lines 6, 7, 8, 9. From each of the two ends of the panel 4 there projects a closure panel 10 from which a tab 11 projects, each closure panel being separated from the adjacent main panel 4 and from the tab 11 by parallel second folding lines 12, 13 perpendicular to the lines 6-9. From both ends of both the main panels 1 and 3 there project flaps, all indicated by the reference numeral 14, which are separated from the respective main panels by third folding lines 15 parallel to the lines 12, 13. At the two ends of each folding line 13 there is a cut intended to form a first aperture 16 (described hereinafter), two further separate apertures 17 being formed by two substantially C-shaped separate cuts made in the panels 10 and in the tabs 11 straddling the folding line 13. In practice, each aperture 16 is separated from the adjacent aperture 17 by an appendix 18 which connects the panel 10 to the tab 11. Finally, it can be seen that two hook-shaped teeth 19, 20 project from the opposing sides of each pair of flaps 14 extending from the same side of the cardboard sheet (Figure 1) or of the box (Figures 2 to 5). The width of each tooth is a maximum at its free end, so that the opposing sides of the two teeth 19, 20 and between them the intermediate free edge of the flap 14 define a free space substantially of dovetail shape, as can be clearly seen in Figures 1, 2 and 5. It should also be noted that the width of the free ends of the teeth 19, 20 is slightly less than that of the respective apertures 17, 16, through which they can hence penetrate when the box is closed. The cardboard sheet shown in Figure 1 is firstly folded along the folding lines 6-9 and the tab 5 is glued to the interior of the panel 1. The tabs 11 are then folded about their folding lines 13 to hence free the apertures 16 and 17, as is clear from Figure 2. After folding the flaps 14 about their folding lines 15, each panel 10 is folded about the line 12 and the relative tab 11 is inserted into the box until the free ends of the teeth 19, 20 pass through the respective apertures 17, 16 to emerge from them (as shown-in Figure 3), from one end and the other of the appendix 18. At this point the end of the box is closed and is securely retained in this closed position by said teeth. In this respect if an attempt is made to open the end by gripping the panel 10 at its free ends and lifting it in the direction of the arrow A (Figure 4), the tab 11 drags the two teeth 19, 20 upwards (relative to said figure). As the flap 14 from which the two teeth project can rotate about the line 15, which is perpendicular to the line 12, the appendix 18 moves relative to the tooth 19, which engages the outside of the appendix (as can be clearly seen from Figure 4), to hence oppose the opening of the end of the box. If the panel 10 is increasingly pulled, the tooth 19 disengages from the appendix 18 and the end of the box can be opened, however the tooth 19 remains visibly damaged, as shown on the left side of Figure 5. The teeth 20 serve not only to increase the resistance to the lifting of the box end, but also help to give it a considerable rigidity and resistance to lateral deformation. Furthermore, if the box is deformed laterally, the teeth 20 interact with the respective appendices 18 to prevent the teeth 19 from leaving the respective apertures 17. In the box embodiment of Figures 1 to 5 a knurling, or preferential breaking line, 30, 31 is shown extending along the tab 11 and the adjacent panel 10 of each of the two ends of the box. When the box end is opened (after being initially closed), the teeth 19, 20 projecting from that flap 14 situated in correspondence with said knurling engage the respective appendix 18 to break the closure panel and the tab on the box end, along this knurling. In this manner, when the end is opened, the panel portion 10A and tab portion 11A remain engaged with the teeth 19, 20, as clearly shown to the right in Figure 5. In this manner it is made immediately and clearly apparent that the end has been opened after having been initially closed, so preventing any fraudulent tampering with the contents of the box. Figures 6 and 7 show two punched cardboard sheets which differ from those of the preceding figures merely by the different knurling, or preferential breaking lines, shown on them. In these figures the same reference numerals as already used in Figures 1 to 5 have been used for simplicity, with the exception of the knurling which is indicated by 40 in Figure 6 (for detaching the entire tab 11) and by 41 in Figure 7 (for detaching only the portion 11B of the tab, when the box is initially opened).

Claims: A box with an end with high resistance to opening, comprising: at least three adjacent main panels separated from each other by first folding lines formed in a punched sheet of flexible material; at least one closure panel for said box, said closure panel projecting from a first main panel and having a projecting tab, the closure panel being separated from said tab and from the adjacent main panel by second folding lines such that said tab is insertable into the box below at least one second main panel; at least two separate apertures formed by cuts provided in correspondence with the folding line between said tab and the respective closure panel, the first aperture being formed by a cut made at the end of said folding line and the second aperture being formed in the tab in proximity to the first aperture; at least one rotatable flap projecting from at least one third main panel, said flap being rotatable about a third folding line which separates it from said third panel and being positionable below the closure panel; coupling elements projecting from said flap and insertable into said apertures to retain said closure panel in its closed position; characterised in that said coupling elements consist of two hook-shaped teeth projecting from said flap and having their greatest width at their free end, the opposing sides of the two hook-shaped teeth and the intermediate flap edge between them defining a substantially dovetail-shaped free space with its maximum width at the edge of the flap, the free ends of the two hook-shaped teeth having a width less than that of the respective apertures through which they can extend and project to retain said tab with its respective closure panel in the closed position. A box as claimed in claim 1, characterised by comprising at least one preferential breaking line extending in proximity to said apertures, to cause breakage of a flap portion when the closure panel is opened. A sheet in the form of a single piece of punched material to form a box with at least one end of high opening resistance, in accordance with the characteristics resulting from claims 1 and 2.

Inventors: LO DUCA CARMELO, LO DUCA, CARMELO
Applicants: GI BI EFFE SRL, GI.BI.EFFE S.R.L.
Application year: 1995
Main classification: B65D5
IPC codes: B65D5