AN INTERLOCKING ARRANGEMENT

Abstract: There is provided an interlocking arrangement for coupling two pieces (10, 11) of paperboard. Projecting portions (17) on one piece (10) and openings on the other piece (11) act as guide means. Locking means comprising parallel sided flaps (20) hinged to said one piece (10) and tongues (24) on said other piece (11) are provided, said tongues (24) being pushed past the flaps (20). The free ends of the tongues (24) are bent back slightly and the flaps (20) engage below the bent back ends.

Description: An Interlocking Arrangement This invention relates to an arrangement for interlocking two pieces of sheet material, particularly but not necessarily made from paperboard. One particular but not exclusive use is in the packaging sleeves used to form a multipack of bottles. Such sleeves are typically wrapped around a number of bottles and the ends of the sleeve are interlocked at the base. However, bottles are generally made with relatively large tolerances which can result in sleeves being too loose or impossible to interlock. According to the present invention there is provided an interlocking arrangement for coupling two pieces of sheet material, the arrangement having guide means which enable the two pieces to be moved towards and away from each other, the guide means comprising at least one projecting portion on one piece and one or more associated openings in said second piece for receiving said one or more projecting portions, and locking means being provided comprising one or more hinged substantially parallel sided tongues formed in either said first or said second piece so as in use to extend towards the other piece and one or more associated substantially parallel sided flaps formed in said other piece and being hingedly connected to said other piece along an edge so as to be movable out of the plane of said other piece to leave one or more holes whereby in use the first and second pieces are brought together ^ so that said projecting portion or portions engage in said opening or openings, and the or each tongue is pushed into engagement with its associated flap which hinges to allow the rongue to pass through the hole, the tongue being pushed past the flap and the free end of the tongue opposite its hinge being bent back such that the flap snaps back to engage the tongue behind the bent back free end, the resilience of the tongue and flan causing interlocking. In preferred arrangements the or each tongue 5 and the opening or each opening are both provided on said second piece. Conveniently one projecting portion is provided having oppositely disposed, generally parallel side edges, the flap being at least partly located between said side edges or imaginary 10 extensions thereof and one opening is provided, the width of the opening being generally equal to the width of the projecting portion. According to a preferred arrangement the edge part of the second piece forward of the opening is ■ ] π hingedly connected to the remainder of the second piece. Ideally the opening is an enclosed opening within the second piece and also the opening is generally arcuate with the edge part being narrowest generally centrally of the opening. on Preferably the tongue forms its hinge generally between the widest points of the opening and further, the tongue is generally central of the opening and extends beyond the general arc of the opening. 25 In preferred arrangements the flap is generally rectangular and the width of the hole is generally the same as the tongue. Also the hinge of the flap may be generally perpendicular to the side edges of the projecting portion or to said imaginary Q extensions of said side edges. Preferably the flap has a nipple formation on its edge opposite the hinge. With a preferred application the two pieces are constituted by the two ends of a paperboard wrap for wrapping an article or'a number of ■3C articles. In use the article or articles may press on the free end of the projecting portion of the first piece and the edge part of the second piece. Preferably the wrapper is for a plurality of bottles and has further apertures for receiving the heels and tops of the bottles. Ideally two or more of said locking arrangements are provided on each wrapper. At the side edges of the wrapper the openings in the second piece may not be enclosed. An embodiment of the invention will now be described in more detail. The description makes reference to the accompanying diagrammatic drawings in which: Figure 1 shows in plan view the two ends of a paperboard sleeve according to the present invention, Figure 2 is a perspective view of part of the figure 1 arrangement being assembled, Figure 3 is a perspective view of the figure 2 arrangement in a later stage of assembly, Figure 4 is a perspective view of part of the figure 3 arrangement in a later stage of assembly, Figure 5 is a sectional view through a finished package showing two bottles in side view. Figure 6 is a plan view of the base of the sleeve showing the bottle positions in chain-dotted lines. Figures 1 to 6 show two ends 10, 11 of a blank 12 made from paperboard for forming a sleeve around a plurality, six in this case, bottles 13. The blank 12 has apertures 14 for receiving the heels of the bottles 13 and fold lines 15, 16 are provided to bend the blank 12 around the bottles 13. In addition the blank 12 will have six more apertures for receiving the crowns of the bottles. These are well known and are not, therefore, shown. Bottles are generally made to quite large tolerances, maybe 1.5-2 mm and it is therefore preferable to use a sleeve which is capable of accommodating these tolerances so that the resulting multipack package is always tight and secure. The two ends of a sleeve blank are generally connected in the base area either by utilising interlocking formations or adhesive. The present arrangement is one of the former systems. The end 10 is formed with projecting portions 0 17. The central two projecting portions have generally parallel side edges 18 which are also parallel to the inside side edges 19 of the end two projecting portions 17. Towards the free ends, the side edges 18, 19 are curved into the front edge 26. 5 Each projecting portion 17 also has a flap 20 located between its side walls. The flaps 20 have straight sides and are hingedly connected to the end 10 along line 21; - This hinge line may be a simple fold, score or cut. The flaps 20 are, therefore, able to pivot 0 out of the general plane of the end 10. The flaps have a nipple formation 20a opposite the hinge line 21. The end 11 is formed with arcuate cuts 22 which are linked by hinge lines 23 which again may be ~ J folds or scores. The width of the projecting portions 17 is generally equal to the distance between the ends of the arcuate cuts 22. A series of four tongues 24 are also provided. The two central tongues 24 bisect a pair of the arcuate cuts 22 and extend slightly beyond an imaginary joining of respective pairs of cuts 22. The front edge portion 25 can be hinged up slightly as is clearly shown in figure 2 about fold lines 23. To make the two ends 10, 11 interlock _ the front edge portion 25 of end 11 is bent up slightly as shown in figure 2. The two ends 10, 11 are then brought ' together so that the projecting portions 17 enter the openings formed in the end 11. The end projecting portions also engage openings in the end 5 11, but it will be apparent that these openings in end 11 are not enclosed as are the central two openings. The result of this stage is clearly shown in figure 3. The tongues 24 are now disposed generally below the flaps 20. Movement between the two ends 10, -JO 11 is also possible and the straight sides 18, 19 and the width of the openings ensure that the movement is in a single fixed direction that is towards and away from each other. The movement enables the sleeve to accommodate the bottle tolerances and there is a range 15 of movement of about 8 mm in this embodiment. When the blank 12 is being wrapped around the bottles 13 it is therefore possible for the blank to be positioned such that the blank tightly grips the bottles 13. When tightly engaged, the tongues 24 are 20 pushed up from below. The tongues 24 then cause the flaps 20 to pivot and the ends of the tongues 24 may be bent back by the position of the hinge lines 21. The tongues 24 will eventually push past the flaps 20 and the end of the tongue will remain bent back 25 slightly as shown by numeral 26 in figures 4 and 5. The resilience of the flaps 20 will cause the flaps 20 to snap back into engagement with the underside of the respective tongues 24. This results in firm interlocking of the ends 10, 11. The nipple 30 formations 20a may also be bent back somewhat by this contact. This provides a larger contact area between the flaps and the tongues thus improving rigidity. The bottles 13 themselves also act to make the structure rigid because they sit on the * ends of the --I- projecting portions 17 and on the front edge portion 25 of end 11. This is more clearly shown in figure 6. It will be appreciated that the curved corners at the front edges 26 of the projecting portions 17 assist in the smooth entry into the openings created by the arcuate slits 22. The arcuate nature of the slits 22 also smoothes the entry. When using the above interlocking system to fasten a sleeve it is best if there are at least two sets of interlocking tongues 24/flaps 20. More sets provide more rigidity. It will also be appreciated that the location of the interlocking means and the guide means could be separated. In other words the projecting portions 17 and guide slits 22 could be located independently of the tongue 24 and flap 20 formations. For example they could be provided alternately along the edges of the ends 10, 11. Also it is not necessary for the tongues 24 to be on the same side 11 as the slits 22. The system could also be used with other materials such as plastics and to wrap other articles such as cans. Also the bottle number and location shown is purely exemplary.

Claims: CLAIMS 1. An interlocking arrangement for coupling two pieces of sheet material, the arrangement having guide means which enable the two pieces to be moved towards and away from each other, the guide means comprising at least one projecting portion on one piece and one or more associated openings in said second piece for receiving said one or more projecting portions, and locking means being provided comprising one or more hinged substantially parallel sided tongues formed in either said first or said second piece so as in use to extend towards the other piece and one or more associated substantially parallel sided flaps formed in said other piece and being hingedly connected to said other piece along an edge so as to be movable out of the plane of said other piece to leave one or more holes whereby in use the first and second pieces are brought together so that said projecting portion or portions engage in said opening or openings, and the or each tongue is pushed into engagement with its associated flap which hinges to allow the tongue to pass through the hole, the tongue being pushed past the flap and the free end of the tongue opposite its hinge being bent back such that the flap snaps back to engage the tongue behind the bent back free end, the resilience of the tongue and flap causing interlocking. 2. An interlocking arrangement as claimed in claim 1 wherein the or each tongue and the opening or each opening are both provided on .-said second piece. 3. An interlocking arrangement as claimed in claim 1 or laim 2 wherein one projecting portion is provided having oppositely disposed, generally parallel side edges, the flap being at least partly located between said side edges or imaginary extensions thereof and one opening is provided, the width of the opening being generally equal to the width of the projecting portion. 0 4. An interlocking arrangement as claimed in claim 3 wherein the edge part of the second piece forward of the opening is hingedly connected to the remainder of the second piece. 5 5. An interlocking arrangement as claimed in claim 4 wherein the opening is an enclosed opening within the second piece and also the opening is generally arcuate with the edge par't being narrowest generally centrally of the opening. 0 6. An interlocking arrangement as claimed in claim 5 wherein the tongue forms its hinge generally between the widest points of the opening and further, the tongue is generally central of the - ? opening and extends beyond the general arc of the opening. An interlocking arrangement as claimed in claim 6 wherein the flap is generally rectangular and the 0 width of the hole is generally the same as the tongue. 8. An interlocking arrangement as claimed in claim 7 wherein the hinge of the flap is generally 5 perpendicular to the side edges of the projecting portion or to said imaginary extensions of said side edges. 9. An interlocking arrangement as claimed in claim 8 wherein the flap has a nipple formation on its edge opposite the hinge. 10. An interlocking arrangement as claimed in any one of claims 1 to 9 wherein the two pieces are constituted by the two ends of a paperboard wrap for wrapping an article or a number of articles. 11. An interlocking arrangement as claimed in claim 10 wherein in use the article or articles press on the free end of the projecting portion of the first piece and the edge part of the second piece. 12. An interlocking arrangement as claimed in any one of claims 1 to 11 wherein the wrapper is for a plurality of bottles and has further apertures for receiving the heels and tops of the bottles.

Inventors: NEGELEN EMANUEL, NEGELEN, EMANUEL
Applicants: NEGELEN EMANUEL, RIVERWOOD INT LTD, RIVERWOOD INTERNATIONAL LIMITED
Application year: 1993
Main classification: B65D71
IPC codes: B65D5, B65D71