This invention relates to a carton packaging machine which is operable to cause progressive erection of carton forming blanks, to permit loading of the partly erected blanks with products, to complete the formation of each carton and to close the latter with the product located therein and to discharge each closed carton from the machine.

The invention is particularly concerned with a machine for use in forming carton sleeves, such machines being known as "sleeving machines". In machines of this type, a stack of blanks is supplied to the machine, and the blanks are fed singularly to the machine and then undergo progressive erection, loading with product, final formation into sleeve form, and then discharge of the sleeve product.

Existing designs of sleeving machines wrap the blank around the product by drawing the blank downwardly onto the top of the product and by folding sides of the blank downwardly so as to lie alongside the product, and then by folding the lower margins of the side of the blank under the product, followed by sealed closure. This manipulation of the blank is somewhat complicated and it is a particularly difficult part of the operation to ensure that the blank is folded under the product and then secured by adhesive in a satisfactory manner.

The pnesent invention is concerned with a carton packaging machine of a general type which is disclosed in more detail in International Publication No W088/04259 and to which reference is directed. The carton packaging machine disclosed therein is operable to cause progressive erection of carton sleeves from a supply of blanks, to permit loading of partly erected blanks with product, to complete the formation of a sleeve around each product and to close the latter with the product located therein and to

discharge the loaded sleeve from the machine, in which the machine comprises: an endless conveyor moveable progressively through a blank-supply station, an erection station, a product loading station, a folding station and a discharge station; a magazine arranged at the blank-supply station for holding a stack of blanks; a suction device arranged to cooperate with the magazine and to operate in timed sequence with the operation of the conveyor in order to engage and to draw blanks individually in turn, in flat form, into the path of travel of the conveyor for engagement thereby; a shaping device arranged at the erection station and engageable by each blank in order to form the blank into a U-shape having a base and a pair of side flaps extending upwardly from the base, each U-shaped blank being then advanced by the conveyor to the loading station at which product can be loaded onto the base; and a folding device arranged at the folding station above the conveyor and engageable with the upper portion of the side flaps, as each loaded blank is advanced to the folding station so as to fold side flaps inwardly into overlapping relation in order to complete the formation of the carton sleeve.

This carton packaging machine therefore enables the product to be loaded downwardly. This permits the product to be located in desired positions readily especially when loading takes place by hand.

The formation of the carton sleeve is thus completed by inwardly folding the side flaps over the top of the product, and this operation is much more readily carried out in a satisfactory and repeatable manner, than by the known technique of underside closure.

The present invention is concerned with the carton packaging machine of the general type referred to above, and which forms the subject of International Publication

V088/04259, but seeks to improve this carton packaging machine in a number of respects, as will become apparent from the subsequent detailed description of the preferred embodimentof the invention herein.

In particular, the carton packaging machine of the invention has been developed primarily though not exclusively, with a view to providing improved loading of cartons derived from blanks which are provided with circular apertures into which plastic pots, such as yoghurt pots can be suspended, and in which the blank is erected into a U-shape and then the side flaps are folded inwardly consecutively so as to overlie the tops of the product containers.

The carton packaging machine of the invention may also provide improved loading of cartons formed from blanks which form a solid base to the cartons. Containers of any shape may be loaded onto the base of the container before the blank is folded to form a complete carton.

Food manufacturers who use carton sleeves to package their products naturally wish to use the smallest amount of cardboard material, consistent with providing safe retention of the products in the packaging, and also with providing packaging which can be readily handled and stacked. However, by providing food products such as yoghurts, which are freely suspended in the manner set out above, with the side flaps inwardly folded so as to overlie the tops of the product containers, this provides a somewhat "floppy" packaging, with the load of the products being born by the base of each blank.

The first aspect of the invention seeks to provide an improved carton packaging machine which is able to handle in an automatic manner blanks which can be readily folded into the required shape, and which provides a secure containment of the products in the packaging.

According to a first aspect of the invention, there is provided a carton packaging machine which is operable to

cause progressive erection of carton sleeves from a supply of blanks, each blank comprises a base and a pair of side flaps which can be folded inwardly so as to overlie the base when loaded with product and in which the machine comprises: an endless conveyor moveable progressively through: a blank-supply station; a first product-loading station; an erection and folding station; and a discharge station; a magazine arranged at the blank-supply station for holding a stack of blanks, and for delivering the blanks individually in turn in flat form into the path of travel of the conveyor for engagement by flights carried by the conveyor; an automatic loading device arranged to guide at least one lane of product toward the conveyor and to load each blank with respective product as the blank is advanced by the conveyor through the loading station; a folding device arranged at the folding station and engageable by each blank in order to form the blank into a U-shape with the base thereof extending substantially horizontally, and the pair of side flaps extending upwardly therefrom and to fold the side flaps inwardly into overlapping relation in order to complete the formation of the carton sleeve.

The automatic loading device is therefore able to load each blank with the product automatically, and with the loading station being arranged at any convenient position along the length of the conveyor. Preferably the loading device has a first guide which extends transversly towards the conveyor, and preferably perpendicularly thereof, and which runs into a second guide which guides the product into movement in a direction generally parallel to the conveyor, whereby the product can then fall under gravity off the end of the second guide and onto ^' the base of each underlying blank as it is conveyed through the loading

station.

Conveniently, the loading device has a first guide which extends transversely toward the conveyor, and which runs into a second guide which guides the product into movement in a direction generally parallel to the conveyor and further comprising ramp means located on the conveyor and positioned substantially below the second guide. The blank thus engages with the product before the product has fallen off the end of the second guide.

Conveniently, each blank comprises a base having at least a pair of circular apertures to receive product to be suspended therein, and the automatic loading is arranged to guide two separate lanes of product towards respective products.

In a preferred mode of use, carton blanks are supplied with at least two pairs of apertures, in which case the machine is provided with a further loading station arranged downstream of the first mentioned loading station, and having its own loading device. The first loading station can therefore fill the first pair of blank apertures with product (which may be the same product eg. the same flavour yoghurt, or two different flavours) and then the second loading station can fill the second pair of blank apertures with further products, which can be different from each other and/or different from the product(s) loaded at the first station if desired.

This provides a flexible arrangement which will be of advantage to food manufacturers, as there will be four supply lanes which can be loaded with any required products eg to provide four yoghurt pots of the same flavour in each carton sleeve, or any desired combinations of flavour in a single carton sleeve.

Preferably the or each loading device includes a pair of rotary indexing devices which are capable of advancing the products individually from each of the lanes from the first guide to the second guide, and conveniently each

indexing device takes the form of a so called "star wheel" which is a rotary device having a plurality of circumferentially spaced sockets or pockets each shaped to be able to receive and to advance the product. The shape of the pockets will of course be determined by the shape of the product which is supplied. Very generally the product will be circular in cross sections, being of cylindrical or frusto-conical form.

According to a second aspect of the invention there is provided a carton-packaging machine which is operable to cause progressive erection of carton sleeves from a supply of blanks, each blank comprising a base and a pair of side flaps which can be folded inwardly so as to overlie the base when loaded with product, and in which the machine comprises: an endless conveyor moveable progressively through: a blank-supply station; a product loading station at which products can be loaded onto respective bases and an erection; and folding station; and a discharge station; a magazine arranged at the blank-supply station for holding a stack of blanks, and for delivering the blanks indivdually in turn in flat form, into the path of travel of the conveyor for engagement by flights carried by the conveyor; a folding device arranged at the folding station and engageable by each blank in order to form the blank into a U-shape with the base thereof extending substantially horizontally and a pair of side flaps extending upwardly therefrom and to fold the side flaps inwardly into overlapping relation in order to complete the formation of the carton sleeve; an elongate support extending along the length of the conveyor and arranged to engage the underside of a mid- region of the base of each blank during advancing movement of the blank from the blank supply station to the discharge station.

By providing the elongate support, the blanks can be supported reliably throughout the process at the various stations of the machine and particularly when the product is loaded into the base when the entire weight of the product is borne by the base of the blank.

Conveniently, the machine is a "two-lane" machine, in which each lane of product can be arranged on a respective side of the elongate support. Further support for the blank during its travel through the various stations of the machine may be provided by means of generally horizontal rails extending alongside and above the upper run of the endless conveyor.

The second aspect of the invention may be used in a machine having the automatic loading device of the first aspect of the invention, or with other types of loading devices, or with machines in which the loading is carried out by hand.

A machine according to the second aspect of the invention may be used with blanks which are provided with circular apertures into which pots can be suspended or with blanks used to form cartons having a solid base.

According to a third aspect of the invention there is provided a carton-packaging machine which is operable to cause progressive erection of carton sleeves from a supply of blanks, each blank comprising a base and a pair of side flaps which can be folded inwardly so as to overlie the base when loaded with product, and in which the machine comprises: an endless conveyor moveable progressively through: a blank-supply station; a product-loading station at which products can be loaded onto respective bases; and an erection and folding station; and a discharge station; a magazine arranged at the blank-supply station for holding a stack of blanks, and for delivering the blanks individually in turn, in flat form, into the path of travel of the conveyor for engagement by flights carried by the

conveyor ; a folding device arranged at the folding station and engageable by each blank in order to form the blank into a U-shape with the base thereof extending blank into a U- shape with the base thereof extending substantially horizontally and the pair of side flaps extending upwardly therefrom and to fold the side flaps inwardly into overlapping relation in order to complete the formation of the carton sleeve; and an overhead guide arranged at the folding station upstream of the folding device, said guide being engageable with the tops of the product to locate the products introduced onto the bases, to locate the products securely in position prior to operation of the folding device.

The guide may comprise a guide plate which extends downwardly and then rearwardly with respect to the direction of travel of the conveyor, so as to engage firmly with tops of the product containers. This can ensure that any improperly loaded product at the loading station, can be automatically located securely in position prior to operation of the folding device.

A safety interlock device may be provided which will cause automatic interuption in the operation of the machine, and particularly the incremental advance of the conveyor in the event of an improperly loaded product container being carried through to engagement with the folding device.

Usually, one of the side flaps is a short side flap and the other is a longer side flap which is capable of overlying the short side flap and also the entire base. A jet of hot melt adhesive may be applied to the upper side of the inwardly folded first flap and the subsequently folded longer flap is then pressed downwardly into adhesive engagement with the first folded short flap.

To further improve the rigidity of the sleeve formed from the blank, additional means may be provided for

securing the longer flap downwardly onto the base. This may involve the use of additional adhesive applied to the upper surface of the base, or alternatively a mechanical interlock may be provided.

Conveniently the mechanical interlock may be provided by punching a locking flap downwardly from the long overlapping sideflap and through a preformed locking recessing base.

The conveyance of the loaded and folded cartons may be caused by means of variable speed endless driving belts which are pressed downwardly into engagement with the upper surfaces of the cartons. This arrangement may operate at a greater speed than that of the conveyor, so that loaded product can be rapidly discharged from the machine, thereby avoiding any risk of "bunching" of cartons taking place at entry to and during transit through, the folding station. The endless belts may be pressed downwardly by elongate rods, and the speed of the belts may be varied to suit requirements, by providing a V-belt and a variable pulley engageable therewith.

The third aspect of the invention may be incorporated into a machine having the automatic loading device of the first aspect of the invention, or into one having the elongate support of the second aspect of the invention. It may also be incorporated into a machine incorporating both the automatic loading device of the first aspect of the invention and the elongate support of the second aspect of the invention.

A machine according to the third aspect of the invention may be used with blanks which are provided with circular apertures into which pots can be suspended, or with blanks used to form cartons having a solid base.

In a machine according to the invention, the erection station may be operable to partially erect the cartons before the product is loaded into them. Alternatively, the erection station may be operable to erect the cartons after

the product is loaded onto them.

Preferably, the machine further comprises sensing means positioned down stream of the loading station. The sensing means are positioned such that the absence of one or more products may be detected, as well as the absence of the blank. If the sensing means detect such the absence, of a product they will cause the endless conveyor to stop in order that the missing product may be replaced.

An embodiment of the invention will now be described by way of example only with reference to the accompanying drawings in which; figure 1 is a schematic plan view of the embodiment of a carton packaging machine according to the invention; figure 2 is a detailed plan view, to an enlarged scale, of the operating components of an automatic product loading device used at one or a pair of product loading stations arranged along the length of the conveyor sshown in figure 1. figure 3 is a detailed side view, to an enlarged scale, showing the means by which product is fed and then guided to fall under gravity into apertured blanks as they are advanced by the conveyor through each loading station; figure 3a is a schematic side view showing an alternative arrangement, by which product is located in the blanks prior to falling off the second guide; figure 4 is a cross-section on line II-II of figure 1 showing the elongate support member; figure-5 shows a side view of a loaded blank before transit through the erection station: and figure 6 is a plan view of a portion of the machine of figure 1 illustrating the position of the sensors.

Referring to the figure 1, a schematic plan view of an embodiment of a carton-packaging machine according to the invention is shown and is designated generally by the reference 10. A blank-supply station 11 is arranged at the upstream .end of the machine, and includes the magazine 12

(not show in detail) which can hold a stack of blanks and permit supply of blanks individually in turn in flat form into the path of travel from the blank supply station 11 and through a product loading station 15, an erection station, a folding station and a discharge station, all of which can be of conventional form, and which are shown schematically by reference 16. By way of example only, the erection and folding mechanism may be as disclosed in more detail in UK Patent application number 8909783.6 filed on 28 April 1989 in the name of Bonar Cooke Carton Limited.

In the illustrated arrangement, each blank 17 has first and second pairs of apertures 18 and 19 into which food product, such as yoghurt containers can be loaded so as to be suspended therefrom. The apertures are arranged in the base 20 of the blank 17, and short side flap 21 and longer side flap 22 extend away from the base 20. As shown in figure 1, blank 17 is discharged in flat form onto the conveyer 14 by the magazine 12, and in this form it is advanced through loading station 15 so as to receive in its apertures product from a two lane automatic loading device provided at the loading station 15.

At the loading station 15, the automatic loading device is able to load the first pair of apertures 18 with product, and downstream of this first loading station 15, there is a further loading station 23 which is able to supply automatically two further lanes of product which are fed towards the conveyor perpendicularly thereof, and then guided along the length of the conveyor, finally to fall under gravity into the second pair of apertures 19.

The loading stations 15 and 23 are generally of similar construction, and the constructional components thereof are shown in more detail in figures 2 and 3. As can be seen from the drawings, each loading station comprises an automatic loading device having a first guide 24 which guides product 25 along two lanes 26 which are side by side in a direction perpendicular to the general

direction of the conveyor 14 and then the first guide 24 merges or runs into a second guide 27 which guides the product 25 via a curved portion 28 to move generally along the length of the conveyor, whereby the product can then fall under gravity off the free end 29 of a rectiliniar portion 27a of the second guide 27 and into the awaiting apertures of each blank. In respect of the loading station 15, the products 25 are received by the first pair of apertures 18, whereas the automatic loading device at the second loading station 23 is able to guide two lanes of product into the second pair of apertures 19.

After issue from the second loading station 20, each blank 17 has four products 25 received in its base apertures, and the blank is still in flat form. In this form the conveyor 14 then conveys the loaded blanks towards the station 16, at which the side flaps 21 and 22 of the blanks are erected into a substantially vertical position, and then the upper edges of the side flaps are engaged and guided inwardly into overlapping relation and sealed closed in any convenient manner.

The two loading stations 15 and 23 can enable each blank to be loaded with any desired combinations of product, such as a single flavour of yoghurt or different flavours, to meet the requirements of the food manufacturer. Different product runs can therefore readily be accommodated merely by change of supply of the products to the four supply lanes of the two loading devices. The product will preferably move under gravity along the first guide 24, and the rectilinear portions 27a of the second guide 27. However, to feed the products from the first guide 24 to the second guide 27, preferably power driven feeding devices are provided, as will now be described with reference to figure 2.

Each lane 26 has associated therewith a rotary indexing device 31 which is able to engage and to advance the products 25 individually along the curve portion 28 and

on to the rectilinear portion 27a of the second guide 27 and these products are advanced in timed sequence with the movement of the conveyor 14 so that the products fall under gravity off the end of the second guide 27 into the apertures 18 or 19 at the stations 15 and 23. Each indexing device 31 has a plurality of circumferentially spaced pockets 32 in which the products 25 are received, and effectively the devices 31 comprise so called "star wheels" .

Figure 3 shows in side view the portion 27a of the second guide 27, and suitable trip mechanisms will be arranged to ensure that product 25 can fall off the end and into the awaiting apertures at the correct time. Also, though not shown trip mechanisms may be arranged at or near the exit ends of the lanes 26, so that product can be advanced to the indexing devices 31 each time a fresh blank is advanced through the loading stations.

Referring to figure 4, an alternative arrangement of the second guide and the conveyor 14, is shown wherein the product 25 does not fall off the second guide until it has engaged in the blank 7. The end portion 29 of the second guide 27 holds the product in a position such that it is generally perpendicular to the conveyor 14. On the conveyor, are positioned three ramps (only one of which is shown). As the blank 17 moves along the conveyor 17 it is raised up by the ramps 35. The product 25 is thus engaged in the blank 17 before it falls off the second guide 29.

Once t-he blanks have been loaded they progress along the endless conveyor 14. During the movement of the blanks through the various stations of the machine, a mid-region 40 of the base 16 of each blank is supported by an elongate support 41 which extends longitudinally of the upper run of the conveyor and just out of engagement with the conveying surface of the conveyor. The flights 13 are shaped as shown in figure 4, so as not to engage the support 41 during movement of the conveyor. The support provided by

the elongate support 41 provides rigidity to the base of each blank during transit through the various stations of the machine, and this is particularly useful during the loading of the base with food product which is suspended therefrom. Additional support for the base of each blank is provided by longitudinally extending side rails (not shown) arranged above the upper run of the conveyor 14, and this may be somewhat similar to the rail support provided in the carton packaging machine disclosed in international publication number V088/04259.

To provide improved location of any improperly located food product, an overhead guide 50 is arranged downstream of the loading station as shown in figure 5, and applies gentle downward pressure onto the upper ends of the food containers. The guide may be hinged along its upper end 50a, and may thus may act as a safety device, causing the conveyor 14 to stop when the guide 50 is moved. Prior to the blanks arriving underneath the guide 50, the blanks pass beneath sensors 60. As shown in figure 6, there are 5 sensors 60. Four of the sensors 60 are each positioned so that they may sense the presence of a respective food product, and the fifth senser 60 is positioned so that it may sense the presence of the blank. In the event of one or more of the sensors 60 detecting the absence of a food product, the conveyor 14 will stop. The problem may then be solved before the process is continued. If however, neither food product, nor blank is present, the conveyor 14 will continue. After the blanks have passed beneath the guide 50, each blank with product located is advanced to a folding device (not shown in detail), and which may take the form of conventional "ploughs" , which apply consecutively inward folding of the short flap 21 and then the longer flap 22, but with the application of hot metal adhesive onto the upper side of short flap 21 immediately prior to application of longer flap 22 which is then adhesiyely pressed downwardly thereon.

For certain uses, this will provide an acceptable form of packaging for this food product, although if additional rigidity is required for the assembled sleeve form of each blank (base plus overlapping side flap 21 and side flap 22), additional adhesive may be applied on the base 16.

Alternatively, a mechanical interlock may be provided, by punching downwardly a locking tab out of the side flap 19 and through a preformed locking recess in the base (20) .