Apparatus and method for applying endless bands to cartons

Abstract: Apparatus and Method for applying an endless band (B) to a carton so that the band encircles the carton with a join (J) of the band disposed in a preselected orientation, comprises gripping means (20, 28, 32) for holding the band and conveying the band along a feed path in such a way that the join is maintained in a controlled orientation and means (34) to alter the configuration of the band so that it is better adapted for application to the carton and to apply the band to the carton.

Description: This invention relates to a machine and method of applying an endless band to an article, in particular a carton, such that the band encircles the article and provides a handle means by which the article can be carried. The invention is particularly, although not exclusively, useful in conjunction with a carton of the type described in EP-A-O 244 047 or GB-A-9120561.6 and apparatus according to the invention may be installed in a packaging system so that it receives endless bands from a machine described in EP-A-0 042 277. It has been found that endless bands applied to cartons of the type in our aforesaid EP-A-O 244 047 and GB-A-9120561.6 to provide a carrying strap can be vulnerable to breakage if the join which connects together opposite ends of a strip of e.g. plastics material to form the band is broken. This can most readily occur if the join in the band is disposed along that part of the band which is intended to be grasped, where the band may be subject to twisting and other treatment leading to the join being put into shear. Likewise the join is susceptible to breakage if it is disposed at a corner of a package where shear forces tending to tear apart the overlapping material of the join is more likely to occur. It has been found that the incidence of breakage can be significantly reduced if the join of such a band is disposed at a location where shear forces on the join are less likely to occur. This is the case when the join is positioned along a carton side wall intermediate the ends of the carton. To this end, the invention seeks to avoid the random application of such endless bands to e.g. cartons but applies such bands so that the position of the end join is controlled and predictable. It is envisaged that the invention may have applicability in situations other than those in which the endless band is required to provide a carrying handle but in which shear forces acting so as to diminish the integrity of the join in the band are present. One aspect of the present invention provides an apparatus for applying to an article an endless band so that the band encircles the article said band being of the type formed by securing a strip of material into a loop and thereby creating a join, the apparatus comprising means to hold the band in a particular orientation, means to convey the band along a feed path in such a way that said join is maintained in controlled orientation, means to apply the band so that it is adapted for engagement about the midriff of the article. According to a feature of this aspect of the invention means may be provided to shrink fit the band in order to secure it about the article. Preferably, said conveying means comprise an endless series of lugs which alter the configuration of the band during conveyance. Another aspect of the invention provides a method of applying an endless band to an article so that the band encircles the article, said band being of the type formed by securing a strip of material into a loop and thereby creating a join said method comprising the steps of conveying said band along a feed path in such a way that said join is maintained in a controlled orientation, applying the band to said article. According to a feature of this aspect of the invention said band, may be applied to the article as a loose fit, temporarily supported about the midriff of said article and thereafter shrink fitted in place to provide said secure fit. Preferably, the configuration of the band is altered during conveyance so that it is better adapted for application to said article. According to another feature of this aspect of the invention, the band may be orientated such that said join is at a leading part of the band during conveyance. According to yet another feature of this aspect of the invention a strip of plastics material may be first formed into a loop and the plastics material then moulded to itself to create said join. According to a still further feature of this aspect of the invention, said article may be a beverage multipack carton and where a continuous succession of said bands may be applied to respective ones of a continuous succession of cartons. Yet another aspect of the invention provides an article fitted with a band applied thereto according to any of the five immediately preceding paragraphs. An embodiment of the invention will now be described, by way of example, with reference to the accompanying drawings, in which:- Figure 1 is a schematic perspective view of apparatus according to the invention; Figures 1a and 1b are details of lugs employed in the apparatus; Figure 2 is a perspective view of a carton having a band applied thereto; and Figure 3 is a side view of apparatus according to the invention. Referring to the drawings, an endless band is formed from a flat elongate strip of plastics material on loop forming equipment such as is described in EP 0 0422 77. In this known process, the endless band is formed by a welding operation in which the two opposite ends of the plastics strip are welded together in overlapping relationship whilst being held in a pair of rotatable vice jaws 10. Thus, a join J is formed in the band B. The band is formed from a pre-stretched plastics strap material and later shrink fitted to the carton by blasts of hot air. It is conceivable that the band is formed from a stretchable material which is stretched in order to be fitted to the carton and, once in place around the carton's girth, released, so that the band will retract and provide a suitably tight fit on the carton. Of course, the band should be formed from appropriate materials in order that either of these fitment techniques can be practised. In this embodiment of the invention, after the band has been formed it is ejected from the loop forming equipment and is deposited onto a conveyor assembly 12 with the notional main axis of the band substantially horizontal and the join J uppermost as shown. Conveyor assembly 12 comprises endless lug chain 14 entrained about upstream and downstream sprockets 16, 18, respectively, and which carries a number of spaced lugs 20 which are upstanding along the upper reach of the chain 14. Likewise, a parallel endless lug chain 22 is entrained about upstream and downstream sprockets 24, 26, respectively and carries a like number of spaced lugs 28 which also are upstanding along the upper reach of the chain 22. A central endless chain set 30 is disposed intermediate the parallel lug chains and also carries a plurality of lugs 32 at locations which are displaced downstream relative to the locations of the lugs of lug chains 14 and 22. Central chain 30 is entrained about upstream and downstream sprockets 34 and 36 respectively. Sprockets 16, 24 and 34 are coaxial as are sprockets 18, 26 and 36. When the band B is ejected from the vice jaws 10 a pair of lugs 20, 28, on lug chains 14, 22, arrive together to receive the band which is then conveyed along the feed path by the conveyor assembly 30. The relative distance between the lug pair 20, 28 and central lug 32, as measured in the direction of movement X, is then reduced so that as the band is carried along the upper reach of the chain assembly it is held pinched between lug pair 20, 28 and the central lug 32. These lugs are all moved into a upstanding position. The band is thus firmly held in the vicinity of the lugs and is moved into a more horizontal plane so that the main axis of the band is reorientated to be substantially vertical. Thus joint J is located in a preselected position, in this case the joint is put into a leading position in the direction of travel of the band. The relative shift between lug pair 20, 28 and central lug 32 can be affected in a number of ways. For example, by one possibility is a speed differential between the outer chain sets and the central chain set. However it is preferred that the central lug incorporates a follower 'tail' which cooperates with a cam (not shown) to rotate the lug backwards relative to the flow direction and by an amount sufficient to accomplish the pinching or clamping function in conjunction with lug pair 20 and 28 whereby a strip of the band is held between the outer lug pair and the central lug with the join J disposed adjacent the central lug 32. As the band is conveyed downstream of the equipment it is engaged by an overhead lug chain assembly 38. Assembly 38 comprises endless chain 40 entrained about an upstream sprocket 42 and a downstream sprocket 43. Chain 40 carries a plurality of lugs 45 which extend downwardly in the lower reach of the assembly 38 towards the lower lug chain assembly 12. Assembly 38 further includes endless chain 44 entrained about an upstream sprocket 46 and a downstream sprocket 47. Chain 44 carries a plurality of lugs 48. Lug chain assembly 38 is constructed so that the chains 40, 44 and the lugs 45, 48 move through divergent paths before continuing along parallel paths. Thus the lugs 45 and 48 of endless chains 40 and 44 enter the band when it is held in a substantially horizontal position at locations remote from the group of lugs 20, 32, 28 from the lower lug chain assemblies. As the upper lugs 45, 48 move through the divergent paths the configuration of the band is made more ovate as it is stretched transversely of the path of movement X until such time as it is able to be conveyed solely by the lugs of the upper lug chain assembly. During the time in which the upper lug chain assembly assumes responsibility for the conveyance of the band, the chains 40, 44 move through parallel paths. The apparatus and hence the feed path X is generally orientated in a downwardly inclined manner towards the flow path F of the stream of cartons so that the band can be engaged by the leading face of the carton initially and, as the carton moves on from this initial engagement position, the band is caused loosely to encircle the carton. In due course, and as best seen in Figure 3 the transversely stretched band is applied to a carton or other article moving in a path of movement below the upper lug chain assembly 38 so that the join J which is disposed approximately midway between the extremities of the band can be positioned along the side wall of a carton. When the band is first applied to the carton, it is a loose fit about the girth of the carton and therefore support means (not shown), such as parallel plates, disposed alongside the path of movement of the carton are provided to give temporary support to the band at about the midriff of the carton. The band is then shrink-fitted in position so that it is a tight fit about the carton by being subjected to blasts of hot air by which stage the support means no longer are necessary.

Claims: Apparatus for applying to an article an endless band so that the band encircles the article said band being of the type formed by securing a strip of material into a loop and thereby creating a join, the apparatus comprising, means to hold the band in a particular orientation, means to convey the band along a feed path in such a way that said join is maintained in a controlled orientation, means to apply the band so that it is adapted for engagement about the midriff of the article. Apparatus according to claim 1 wherein means are provided to shrink fit the band in order to secure it about the article. Apparatus according to claim 1 or claim 2 wherein said conveying means comprise an endless series of lugs which alter the configuration of the band during conveyance. Apparatus according to any of claims 1,2 or 3 further comprises means to hold the band in a controlled orientation during and immediately after formation of the band from a loop, which holding means releases the band as it is conveyed by the conveying means. A method of applying an endless band to an article so that the band encircles the article, said band being of the type formed by securing a strip of material into a loop and thereby creating a join, said method comprising the steps of conveying said band along a feed path in such a way that said join is maintained in a controlled orientation, applying the band to said article. A method according to claim 5 wherein said band is applied to the article as a loose fit, temporarily supported about the midriff of said article and thereafter shrink fitted in place to provide said secure fit. A method according to claim 5 or claim 6 wherein the configuration of the band is altered during conveyance so that it is better adapted for application to said article. A method according to any of claims 5 to 7 wherein the band is orientated such that said join is at a leading part of the band during conveyance. A method according to any of claims 5 to 8 further comprising the step of forming a strip of plastics material into a loop and welding the plastics material to itself to create said join. A method according to any of claims 5 to 9 wherein said article is a beverage multipack carton and wherein a continuous succession of said bands is applied to respective ones of a continuous succession of cartons. An article fitted with a band applied thereto according to any of claims 5 to 10.

Inventors: LEBRAS PHILIPPE, LEBRAS, PHILIPPE
Applicants: MEAD CORP, THE MEAD CORPORATION
Application year: 1992
Main classification: B65B61
IPC codes: B65B61