CA1196563A - Apparatus for attaching cover and display attachments to multipacks of containers - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

A multipack comprises a plurality of containers such as cans tightly held in an array by a sheet plastics coupler which has apertures through which the tops of the containers protrude. The tops of the containers are pro-vided with end closures and said multipack includes a cover attachment formed from a blank of heat-sealable sheet material having a plane portion which covers these end closures, and a plurality of tabs integral with the plane portion which are folded downwardly and connected by heat sealing to the coupler at the outer periphery of the multi-pack. This configuration is easier to produce than known arrangements and is less likely to become damaged during storage and handling. The invention further provides an apparatus for the high speed attachment of said blanks to said couplers.

Description

APPARATUS FOR ATTACHING ~O~ER AND DISPLAY ATTACHMENTS
TO MULTIPACKS OF CONT~AINERS
This invention relates to apparatus for attaching cover and display attachments -to multipacks, that is to say, packages in which a plurality o~ articles are secured together for retailing as a single item. The invention has particular application t apparatus for attaching cover snd display attachments to multi-packs in which a plurality of cans, especially cans for carbona-ted beverages and having easy opening end closures at one end, are releasably secured together in an array by a sheet plastics coupler such as is marketed in the UK under the trade name Hi-Cone (Registered Trade Mark); the coupler has apertures through which end closures of the cans are made to project, the size of the apertures being such that the cans are then tightly held in position by tension in the coupler material.
Al-though they are cheap to manufacture and apply, sheet plastics couplers for can multipacks suffer from the dis-advantage -that they are difficult to print, and moreover do not provide any substantial area on which promo-tional matter or technical information (e.g. a bar coding) could be printed.
Furthermore, the can end closures under which the coupler is located are unpro-tected from dust and o-ther contamination;
therefore, particularly if they are of the easy-opening kind, these closures will of-ten require to be cleaned if the product in the cans is -to be dispensed hygenically.
It has already been proposed to provide a cover and display at-tachment for a container multipack having a sheet plastics co~lpler. The at-tachment is made of paperboard or . ., 3iS~3 like material and is in the form of a blank which is disposed to overlie the can end closures but separated from the double seams of the closures by edge portions of the coupler material formed around the container-receiving apertures in the coupler. I'he blank is wholly plane, being devoid of any folding or other deformation. It is attached to the coupler by heat sealing to the upper faces presented above the double seams by the above-mentioned edge portions of the coupler.
This arrangement, however, suffers from various shortcomings, both in the sealing of the attachment to the multipack and in the efficacy of the attachment in use.
Among these shortcomings are the following:-(a) The formation of the edge portions of the coupler may 15 require the coupler to be thermoformed rather than stamped. This will tend to increase manufacturing costs and reduce production rates.

(b) Because of the existence of the edge portions, the coupler no longer possesses continuous free edges which can 20 securely lodge beneath the double seams of the containers to hold the coupler firmly in position.

(c) En~agement of the coupler beneath the container double seams takec; place essentially along fold lines by which the ec1ye portions are carried Erom the remainder of the

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coupler; any attempt to use the cover and display attachment to carry the multipack will tend to unfold these fold lines and so release the containers prematurelyO

(d) It is dif~icult to provide the cover and display attachment with a satisfactory easy-open facility, for example tear lines in the board material, without introducing a tendency for th~ attachment to tear or otherwise become damaged during normal handling, transit etc. of the multipack~

10 (e) The cover and display attachment is closely coupled to the underlying containers via the coupler and is therefore unable to accommodate itself to any great extent to relative movement of the containers, for example when one container is tilted or lifted in relation to the others;
15 because of this lack of flexibility, the attachment can, in some circumstances, be inadvertently torn or detached from the coupler.

(f) Because the attachment is not folded or otherwise deformed, heat sealing is only practicable by heat 20 conduction through the attachment material; this is inherently slow, and liable to impose a substantial limitation on the throughput of an autornatic machine for assemblin~ the attachments on a succession of the multip~cks passing along a conveyor.

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6;3 It has been proposed in US Pa-tent Specifica-tion No.
3355013 to provide a cover sheet for a multipack with spaced flanges or tabs adapted to be folded down so as to overlie and to be heat-sealed to adjacent portions of the coupler.
The present invention seeks to substantially reduce or overcome at least some of the disadvan-tages mentioned above and in particular to provide an apparatus capable of attaching, reliably and at high speed7 a plurality of cover and display attachments in -the form of blanks to a succession of multipacks.
~ ccordingly,the present invention provides appara-tus for attaching blanks of a heat-sealable sheet material to multipacks each comprising a plurality of containers in an array and a sheet plastics coupler having apertures -through which end closures of the containers project and which are dimensioned so that the containers are tightly held by tension in the coupler material, each blank having a plane ;5~

portion by which it overlies and substantially covers the end closures of a said multipac~, and a plurality of tabs integrally joined to the plane portion along two opposed sides thereof and foldab:Le downwardly in relation to the plane portion to heat sealed connection with the coupler along opposed sides of the multipack~ the apparatus comprising conveyor means for transporting a succession of said multipacks along a generally horizontal path, a reservoir for a plurality of said blanks, applicator means 10 operating in timed relation to said conveyor means to place blanks individually upon said multipacks moving along said conveyor means with the tabs of said blanks disposed laterally in relation to the conveyor path and, along each side of the conveyor patht heating means for directing hot 15 gas onto said tabs and onto the lateral surfaces of said coupler whereby to render them heat-sealable together, folding means for folding the tabs downwardly adjacent said lateral surfaces of the coupler, and pressure means for holding the tabs against the coupler to heat seal the same 20 to one another.
Various aspects and features of the invention will become apparent from the following description of embodiments of the invention, given by way of example and with reference to the accompanying drawings. In the 25 drawings:-Figure l shows a first blank for forming a cover anddisplay attachment for a multipack formed of four easy-opening cans in two-by-two array~ and a sheet plastics coupler attaching the cans together;
Figure 2 shows the sheet plastics coupler of the multipack;
Figure 3 is a side elevation of the multipack showing a pair of cans with the coupler and the cover and display attachment in position.
Figure 4 shows a detail of the multipack of Figure 3;
Figure 5 shows a second blank for a cover and display 10 attachment for a two-by-two multipack;
~ igure 6 shows a third blank for a cover and display attach~ent for a two-by two multipack;
Figure 7 shows a blank corresponding to the blank of Figure l but adapted for a two-by-three multipack;
Figure 8 shows in side elevation an apparatus for automatically positioning and sealing the blanks of Figure l on two-by-two multipacks so as to orm covered multipacks as shown in Figure 3;
Figure 9 shows the apparatus of Figure 8 in plan view;
Figure lOA to lOE variously show different stageq in the operation of the apparatus to seal the blanks to the multipacks; and Figure ll is a plan view of a multipack when at the stage depicted in Fi~ure lOA~
Referring now to Figure 1, a blank of carton board sheet material is adapted to orm a cover and display attachment for a multipack having four conventional easy-opening cans arranged in two-by-two array and held releasably together by a sheet plastics coupler s~ch as is marketed in U~ under the trade name Hi-Cone (Registered Trade iiark). The blank is coated on its upper side with a 5 plastics coating of, for example, polyethylene or polypropylene to provide moisture and dust resistance. A
further plastics coating on the underside of the blank enables portions of the blank to be directly heat-sealed to the coupler as will later be described.
~'he coupler is shown in Figure 2 in the plane form in which it is initially applied to the cans. In known manner the coupler has four holes 13 through which the double seams of the easy-opening end closures of the cans are to project, the coupler material around the cans then engaging generally 15 edgewise, and with peripheral tension, beneath the double seams to hold the coupler releasably in position on the cans. Often the can bodies will be necked-in adjacent to the double seams; the coupler material around the margins of each hole 13 then substantially follows the neck contour.

In addition to the four can-receiving holes 13 previously mentioned, the coupler has a central finger aperture 14 to acilitate carrying by the user; in addition, in order to ~acilitate folding it has elongate creases and/or slits 15 formed along the bridges 16 joining the four 25lobes 17 in which the can-receiving holes 13 are formed.
Reverting again to ~igure 1, the blank has mutually perpendicular axes of symmetry XX and YY. It has four lobes 1 L~5~3 41 each disposed and dlmensioned to cover one of the cans, and an access aperture 42 disposed at its centreO The outer periphery of the blank ~etween each pair of adj~cent lobes 41 is, as shown, indented at 43 to assist the user to grasp the coupler between thumb and forefinger for carrying the multipack, Each lobe 41 carries a tab 44 integrally joined along a hinge formed by a crease or score line 45, the tabs 44 being arranged in two pairs of aligned tabs on which can 10 hereinafter be considered as side edges of the blank. In order to attach the blank to the multipack as a cover and display attachment, these tabs are downfolded through 90 and at their free ends are heat sealed directly to the coupler material below the double seams 9 of the cans, as 15 shown in Figure 3 where the heat seals are represented by the cross-hatched areas 46 and the attachment and coupler are generally and respectively denoted by the reference numerals 8 and 11. The detail of the heat-sealing is also shown to a greater scale in Figure 4. It will be understood 20 that the heat seals are formed between the plastics material of the coating on the underside of the blank and the plastics material of the coupler, these plastics materials being compatible with one another. Typically, the coating ~ material is polypropylene, and the coupler material is high ; 25 density polyethylene.
i After its attachment to the multipack the blank provides a cover for the cans 10 to the point of use, its lobes 41 then lying against (or closely adjacent to) the terminal top edges of the cans provided by the double seams 9 so as to cover the easy-open closures against any substantial ingress of dust or other contamination. In addition, the attachment as a whole provides a substantial and plane area of readily printable material on which may be printed promotional matter as well as technical information such, for example, as a bar coding; the printing may be multicolour if desired. The access aperture 42 provides 10 access to the finger aperture 14 (Figure 2) of the coupler so that the multipack can be carried by the user by grasping it between thumb and forefinger inserted through the aperture 14. However, with suitable thickness of the board material and its plastics ooatings, the attachment may be 15 given sufficient rigidity and tensile strength to enable it~
if necessary, to bear the weight of the multipack by itself~
In addition to its attachment along a hinge line 45, each tab 44 has a line of weakening 51 formed parallel to the hinge line as by creasing or scoring~ The purpose of 20 this line of weakening is to assist the tab to flex and so enable the attachment to accommodate readily to relative longitudinal movement of the cans of the multipack, in particular during carriage by the consumer. Two or more such lines of weakening 51 may be provided in parallel in 25each tab 44 if desired.
Figure 5 shows a second embodiment of the invention.
~he cover and display attachment of this embodiment has _g _ heat-sealable tabs 44 as in the previous ernbodiment, but its access aperture 42 and recesses 43 are closed by panels 146, 147 so that the attachment provides tamper-evidence and a continuous display area. The panels 146, 1~7 are each attached by 5 frangible bridges 4~ in interrupted cut lines L~9, and by hinge lines 50. The consumer may -therefore -tear or bend -the panels 146~ 147 out of the way -to allow finger access to the access aperture 42 and recesses 43.
Figure 6 shows an embodiment having two lobes L~1 each 10 dimensioned to cover the top of two cans 10 of a 2 x 2 multipack. The blank has a central access aperture 42, and two finger recesses 43~ Four tabs 44 are provided~ arranged in two pairs of aligned tabs each pair of which is carried by a lobe L~1. In a modification which adapts -the blank for 15 attachment by the apparatus of Figures 8 to 11, the two pairs of aligned tabs span the recesses 43 rather than being located one to each side of them, as shown.
The invention is not limited in application to attachments for multipacks having a 2 x 2 array as 20 particularly described above. It may be applied -to multipacks having only a single row of ar-ticles or having more than two pairs of articles. Figure 7 shows a blank for attachment to a multipack of cans arranged in 2 x 3 array.
The blank can be r~adily seen to be analogous in arrangemen-t 25 to -that of Figure 1, and is therefore not described. As before, -the blank is attached to -the u~derlying plastics coupler by direc-t hea-t-sealing of i-ts -tabs 4L~ The blanks of Figures 5 and 6 can likewise be readily adapted for a 2 x

3 multipack.
Reference is now made to Figures 8 to ll which illustrate the preferred apparatus and method by which the ~lank of Figure l is positioned on the multipack and sealed in position as a cover and display attachment 8. ~ith minor modification to the blank and/or to the apparatus, the apparatus can also be used for the cover and display attachments of Figures 5, 6 and 7.
Figures 8 and 9 show the apparatus respectively in diagrammatic side elevation and plan view. The apparatus has a frame 60 supported on legs 61. A belt conveyor 62 is supported by the frame to circulate between upstream and downstream rollers 63, 64, so that multipacks 65 of four 15 cans lO in two-by-two array can be placed on its horizontal upper run 66 and carried by the conveyor in the rightward direction as shown~ For that purpose downstream roller 64 is driven in the appropriate direction by an electric motor 67 acting through chain drives 69, 70 in series.
The multipacks 65 are placed manually or by machine on the left hand end of the conveyor 62 at a random or regular spacing. ~rom there they are carried into the nip of a pair of metering conveyors 72. These conveyors have chains 73 on which are carried dogs 74 having a regular spacing equal to 25 the length of one multipack 65.
The chains of the metering conveyors are trained around sprockets 75~ 76, 77 mounted for rotation on vertical a~es.

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The sprockets 75 at the downstream ends of the metering conveyors are driven by the motor 67 via a chain drive 68, mechanical clutch 140, chain drive 78 and gearbox 79~ so that the opposed inner runs of the metering conveyors move in the same direction as the conveyor 62 but at a slightly lower speed. rlultipacks passing between the metering conveyors are accordingly controlled by those conveyors to a predetermined speed at which they abut one another end-to-end whilst slipping slowly backwards in relation to the 10 conveyor 62. The metering conveyors accordingly form a metering station for the apparatus.
The clutch 140 is normally engaged so that the metering conveyors are driven to feed the multipacks one-by-one into the heat-sealing station which follows. However, if for any 15 reason the number of multipacks in and upstream of the meteriny station falls below a predetermined number, a switch (not shown) is automatically closed and the clutch 140 operates to stop the metering conveyors until the head of multipacks is restored whereupon the clutch is again 20 engaged. In this way lt is ensured that the multipacks are fed through the apparatus in the correct timed relation despite interruptions which may occur from time to time in the supply of multipacks to the conveyor 62.
An applicator device 80 is located above the multipack 25 path through the appara~us at the end of the metering station, It has a magazine 81 arranged to be manually loaded with a stack of blanks 82 of the cover and display 36S~3 attachments with their tabs 44 disposed at the sides of the blan~ (in relation to the multipack path.) The device 80 further comprises an applicator wheel 83 arranged for transferring the blanks in turn from the magazine to the multipacks passing beneath.
The applicator wheel 83 is rotatable about a horizontal, transverse axis. It is driven in an anticlockwise direction (Figure l) about this axis by means of the motor 67, and a chain drive 84. It has four take-off 10 a~ns 85 with sucker heads 86 carried at 90 intervals about its periphery and connectable to a vacuum source (not shown). The rotation of the applicator wheel i5 synchronised with the movement of the metering conveyors 72 so as accurately to present blanks 82 drawn from the front 15 Of the magazine 81 in turn onto the multipacks passing the downstream end of the metering conveyors. For this purpose the applicatQr device 80 includes valving (not shown) operable with rotation of the wheel 83 to ~onnect the take-off arms 85 in turn to the vacuum source as they approach 20 the magazine and to subsequently disconnect the arms from the vacuum source at the moment in time when they present the blank 82 drawn from the magazine properl~ to a multipack 65. Moreover, the magaæine has a spring-biassed retractable pusher plate 87 ~o engage resiliently behind the stack of 25 blanks 82, and a suitable stop ~not shown) at the front end of the maga~ine to hold the leading blank until it is drawn off by a take-oEf arm 85, l.L~&~5~;3 ~ fter control by the metering convevors 72 upto and under the applicator device 80, control of the multipacks passin~ along the conveyor 62 is taken over by two side conveyors 90 having chains 9l mounting dogs 92 (see also 5 F igure ll).
The side conveyors have their chains trained around sprockets 93, 94, 95 for circulation in a common horizonta1 plane which is located above the common horizontal plane of the metering con~eyors 72. The sprockets 95 of the side 10 conveyors 90 are coaxial with the drive sprockets 75 of the metering conveyors 72 beneath them, but are free to rotate. Circulating drive for the side conveyors is provided by motor 67 acting through the chain drive 69 and a gearbox ll3.
The dogs 92 of the side conveyors 90 have a pitch equal to, or slightly greater than the length of one multipack.
The metering and side conveyors are so synchronised that the dogs 92 engage between the cans lO of the individual multipacks, rather than between the multipacks themselves in 20 the manner of the dogs 74 o the metering conveyors. It will particularly be noted that the blanks 82 are placed on the multipacks by the applicator device 80 at a time when the metering conveyors still have control of the multipacks and the dogs 92 of the side conveyors are approaching, but 25 not fully engaged with, the multipacks. This allows sufficient freedom for the blanks to be placed in position whilst ensuring that very shortly afterwards the blanks are enyaged, located and held before they can be dislodged.

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Figure 11 in combination with Figure lOA shows clearly the arrangement of the dogs 92 and their engagement with the multipacks. It will be seen that the dogs nest snuyly in the recesses formed between the cans so as to achieve accurate lateral and longitudinal location of the multipack as the latter moves along the conveyor 62. They project upwardly beyond the cans so as by engaging the blank 82 at its side recesses 43 ~Figure 1) to locate the attachment accurately on the multipack for the tabs 44 to be bent down 10 and heat-sealed into position. Location in the longitudinal sense is achieved by cam action of the dogs engaging the sloping surfaces of the recesses 43. Cutaways 96 are formed along the top outside edge of the dogs 92 for the purpose now to become apparent.
After engagement by the dogs 92, the multipacks 65 are carried by the conveyor 62, under control by the side conveyors 90, through a heating station in which hot air issuing from elongate nozzles 101~ 102 fed from manifolds 103 (Figures 9, lOC~ is directed horizontally against, 20 respectively, the underside of the tabs 44 and the exterior surfaces of the coupler 9 along the sides of the multipack path. The hot air is generated by heat exchangers 150 (Figures 8, 9) with an associated blower (not shown) in the manner described in U.K. Patent 1071040 to which the readers 25 attention is directed. It is of sufficient temperature and is applied for a suEEicient length of time to cause plastics material of the tabs and of the coupler to fuse and so 5~3 enable a heat-seal bond to be subsequently formed between them as will later be seen.
As is apparent from Figure lOC, the hot air is applied to the tabs 44 when they are held in uplifted, vertically extended positions by bars 104 of which one extends along each side of the conveyor 6~ accommodated by the cutaways 96 in the dogs 92. Further bars 105 engage the upper surface of the blank so as to provide downward restraint for the blank at the elbows formed along the hinge lines 45.
The bars 104~ 105 are carried and cooled by rails 106, 107 fed with cooling water from a supply source (not shown). They are shaped so that as the multipack and blank move along them they progressively bend the tabs 44 of the blank up from their original horizontal positions of Figure 15 lGA , and through the inclined position shown in Figure lOB
to the vertical position of Figure lOCat which heating by the hot air takes place.
After the heating has been accomplished, further movement of the multipack and blank carries them past the 20 downs~ream end of the bars 104 so that oontinuations of the bars 105 can subsequently bend the tabs 44 progressively to a substantially downwardly extending position. Figure lOD
shows an intermediate position of the tabs 44 during this movement. For clarity the items 101 to 107 are omitted from 25 the left: hand side of each of Figures lOA to lOE.
It will therefore be understood that on leaving the bars 105 the blank has its tabs 44 inclined downwardly;

t;5 i3 moreover, the tabs and the opposed surfaces presented by the coupler 11 are still in a hot, heat-sealable condition.
Heat-sealing between the tabs and the coupler is achieved by endless pressure belts lln trained about pulleyc 111 and 11 at their upstream and downstream encls, and about idler pulleys 115.
The pressure belts are of circular cross~section and made of a single strand of a plastics material having substantial elasticity e.g. polypropylene. The pulleys 111 10 are mounted for rotation about aligned and transverse, horizontal axes, whereas the pulleys 112 are rotatable about vertical axes and drivable from the drive motor 67 via the gearbox 113 previously mentionedO The circulating speed of the pressure belts 110 is the same as that of the side 15 conveyors 90 so as not to exerte any force tending to tear the relatively fragile tabs 44 along their hinge lines 45.
For each pressure belt 110 the pulleys are arranged so that the lower run of the belt lies in the horizontal plane of the median line of the downfolded tabs 44. Larger idler 20 pulleys 114 biassed inwardly by springs 118 (see Figure 10~), further constrain an upstream portion 116 of the lower run to circulate against the tabs 44, so pressing them into heat-sealed relation with the coupler 11 and holding -them in that position until the heat-seal is permanently forrned.
~fter leaving the pressure belts 110 and, at the same time, the side conveyors 90, the rnultipacks, with their cover and display attachments 8 in position as shown, continue along the conveyor 62 for subs~quent dispatch and distribution.
The invention is not limited in application to multipacks of necked-in beverage cans having double-seamed easy-open end closures as particularly described. I-t may have application to multipacks of other types of container but joined7 as before, by a sheet plastics coupler engaged behind projections on the containers.
The cover and display attachment may be of plastics sheet material rather than plastics coated cartonboard (or 10 other paper-based material) as particularly described~

Claims (8)

1. Apparatus for attaching blanks of a heat-sealable sheet material to multipacks each comprising a plurality of containers in an array and a sheet plastics coupler having apertures through which end closures of the containers project and which are dimensioned so that the containers are tightly held by tension in the coupler material, each blank having a plane portion by which it overlies and substantially covers the end closures of a said multipack and a plurality of tabs integrally joined to the plane portion along two opposed sides thereof and foldable downwardly in relation to the plane portion to heat sealed connection with the coupler along opposed sides of the multipack the apparatus comprising conveyor means for transporting a succession of said multipacks along a generally horizontal path, a reservoir for a plurality of said blanks, applicator means operating in timed relation to said conveyor means to place blanks individually upon said multipacks moving along said conveyor means with the tabs of said blanks disposed laterally in relation to the conveyor path and, along each side of the conveyor path, heating means for directing hot gas onto said tabs and onto the laterial surfaces of said coupler whereby to render them heat-sealable together, folding means for folding the tabs downwardly adjacent said lateral surfaces of the coupler, and pressure means for holding the tabs against the coupler to heat seal the same together.

2. Apparatus according to claim 1, wherein the conveyor means comprises a bottom conveyor operating at a first speed and arranged to carry the multipacks through the apparatus between input and discharge ends, a metering side conveyor disposed immediately the ends of the bottom conveyor and operated at a second speed which is smaller than the first speed so as to hold a plurality of the multipacks in abutting relation and to feed them onwards at said second speed to said applicator means, and a locating side conveyor disposed to receive the multipacks with the blanks thereon from the metering side conveyor and arranged to carry them in succession through the heating means, folding means and pressure means.

3. Apparatus according to claim 2, wherein the metering side conveyor has dog members with a pitch equal to the multipack length and arranged to engage between the multipacks, the locating side conveyor having further dog members arranged to engage individual multipacks between adjacent containers thereof.

4. Apparatus according to claim 2, wherein the locating side conveyor is operated at said second speed so that the heating means, folding means and pressure means are effective upon multipacks in abutting relationship.

5. Apparatus according to claim 3, wherein the dog members of the locating side conveyor are arranged to engage the multipacks and the blanks thereon so as to locate the blanks in relation to the multipacks until the heat seals have been made.

6. Apparatus according to claim 1, further including an additional folding means arranged upstream of the heating means to fold the tabs into vertically uplifted positions, the heating means comprising upper and lower nozzles arranged to direct hot gas horizontally on to, respectively, said vertically uplifted tabs and said lateral surfaces of the coupler.

7. Apparatus according to claim 1, wherein said folding means comprises plough bars arranged to fold the tabs into vertically uplifted positions upstream of the heating means, to maintain the tabs in the uplifted positions during passage of the multipacks past the heating means, and, downstream of the heating means, to fold the tabs downwardly to substantially vertical positions at which the pressure means may be effective, the heating means comprising upper and lower nozzles arranged to direct hot gas horizontally on to, respectively, said vertically uplifted tabs and said lateral surfaces of the coupler.

8. Apparatus according to claim 1, wherein the pressure means comprises an endless belt arranged to circulate at the speed of the multipacks as they pass along the conveyor means, the belt being biassed inwardly and resiliently into engagement with the tabs.