BACKGROUND OF INVENTION In the cheese making industry cheese curd is vacuum transferred into cheese towers from their cheese making machine. The vacuum applied pulls the curds and whey down the tower compressing the curd into a firm block.

The whey is removed and the curd is formed into a block. A ram operated knife plate cuts the block to a predetermined height (generally equating to approximately 20 kg) and then a second ram pushes the cheese block out of the tower through a bag holding clamp into a bag. The bagged cheese block then travels down a conveyor, is check weighed, gusseted by hand and manually placed into a sealing machine to be vacuum sealed.

A single cheese tower has a throughput of approximately 1000 kg per hour. In New Zealand, most cheddarcheese factories have at least 10 cheese towers and process about 10 tonnes of cheese per hour. Thus, there are typically 500 blocks of 20 kg cheese passing out of the cheese towers for bagging every hour.

At present the cheese bags are placed onto the cheese tower bag holding clamps manually. Similarly, the filled bags are gusseted manually. A cheese factory processing 10 tonnes of cheese per hour will require at least five people to carry out the bag placing and gusseting operations. Such a

factory working on a 24-hour operation would require four rotating 1 2-hour shifts, equating to at least 20 people employed to place and gusset cheese bags.

Whilst the above description, and the examples used in this specification, relate to the automated packaging of cheese blocks, it will be appreciated that the method and apparatus of the present invention is not limited to cheese packaging but also extends to the automated packaging of other products in gusseted bags.

Thus, it is an object of the invention to provide a packaging method and apparatus which would reduce or overcome at least some of the above mentioned problems, or which at least provides the public with a useful alternative.

Other objects of the invention may become apparent from the following description which is given by way of example only.

SUMMARY OF INVENTION According to one aspect of the present invention there is provided bag opening apparatus adapted to feed and open a gusseted bag, the apparatus including: -two pairs of gripping means adapted, in use, to grip an edge of each gusset of a gusseted bag, -drive means adapted to feed gripped edges from a first position to a second position, -opening means adapted to adjust the gripped edges associated with each pair of gripping means from an adjacent configuration in which the edges are substantially parallel to one another, in the first

position, to a separated configuration in which the edges are spaced- apart, in the second position, -the drive means and opening means adapted to operate simultaneously to feed and open a gusseted bag.

According to a further aspect of the invention there is provided a method of automated feeding and opening of a gusseted bag, the method including the steps of: -gripping each edge of each gusset of a gusseted bag with two pairs of gripping means, -feeding the gripped edges from a first position to a second position, and -adjusting the gripped edges from an adjacent configuration in which the edges are substantially parallel to one another, in the first position, to a separated configuration in which the edges are spaced- apart, in the second position, and wherein the feeding and adjusting steps operate simultaneously.

According to a further aspect of the present invention there is provided a packaging method adapted to enable automated feeding and opening of a gusseted bag from a web or bag reel, said method including the steps of: -simultaneously feeding and opening a gusseted bag from a web or reel of bags, -holding the open end of the bag, and -separating the held bag from the web or reel of bags, by applying a force between the held open end of the bag and the web or reel of bags.

In a further preferred form, the method may further include the steps of: -loading product into the opened bag end, -gusseting the previously opened bag end, and -securing the gusseted configuration of the previously opened bag end.

Other aspects of the present invention may become apparent from the following description which is given by way of example only and with reference to the accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS Figure 1: shows a perspective view of the apparatus of the present invention in one embodiment; Figure 2: shows a perspective view of the feeding means of the apparatus of Figure 1 with the jaws in an open configuration; Figure 3: shows a perspective view of the feeding means of the apparatus of Figure 1 with the jaws in a closed configuration; Figure 4: shows a side view of the feeding means in the configuration of Figure2; Figure 5: shows a front view of the feeding apparatus with the jaws in an open configuration; Figure 6: shows a perspective view of the holding means of the apparatus of the present invention in one preferred form, with jaws in an open configuration;

Figure 7: shows a perspective view of the holding means of Figure 6 with the jaws in a closed configuration; Figure 8: shows a side view of the holding means in the configuration of Figure 6; Figure 9: shows a front view of the holding means in the configuration of Figure 6.

Figure 10: shows a perspective view of the apparatus of the invention in an alternative, preferred form; Figure 11 : shows a perspective view of the holding means of the invention, in an alternative, preferred form, and as included in the embodiment of Figure 10; Figure 12: shows a side view of the holding means of Figure 11; and Figure 13: shows a front view of the folding means of Figure 11.

DETAILEDDESCRIPTION OF INVENTION With reference to Figure 1, apparatus at the present invention in one preferred form includes feeding means 1 from which a bag can be automatically fed and opened, holding means 2 adapted to hold an open end of a bag and means for enabling separation of a held bag from a continuous web of bags. Details of the feeding means and separation means may be seen in Figures 2 to 5, whilst details of the holding means are shown in Figures 6 to 9.

With reference to Figures 2 to 5, a bag reel 3 of pre-gusseted film rests in a travelling support frame 4. Rollers 5 are provided to direct the web 6 to web feeding jaws 7. Each jaw 7 is substantially the width of the web 6 and

includes, on each side, a lip 8 (or gusset edge support) having a surface of ultra high molecular weight polyethelene, and a timing belt 9. These belts 9 on each side are driven by timing pulleys 10 on shafts 11 attached to a motor 12 driving cogged gears 19 on the pulley shafts. The belts 9 are tensioned so as to trap an edge of a gusset of the web between the belt 9 and the lip 8 to drive the web along a jaw. They may also have a soft rubber coating.

Pneumatically operated cylinders 13 are provided on each side of the jaws 7 to open and close the jaws.

At a front end 14 of the jaws 7 clamping means are provided. The clamping means comprises transverse members 16 at the front end 14 of each jaw preferably each member 16 having a rubber-type compound on the inner surface to facilitate a gripping clamp, and small pneumatic cylinders 17 associated with at least one of the jaws (in the example shown, the upper jaw). The cylinders 17 are adapted to force one transverse member onto the other to form a secure clamp on a web held between the closed jaws, in use.

Referring again to Figure 1, the whole of the feeding means 1 is adjustably mounted on a frame 20 with drive means (not shown) to enable vertical movement of the feeding means 1 on sub-frame 21 through linear bearings 22 or other alternative guidance system, as will be appreciated by persons skilled in the art. This enables the feeding means to be moved between a lower operating position (as in Figure 1) and an upper retracted position. It is movement between the lower operating position and the upper resting position that provides a separation force for separating a bag, along a perforation line, from the web 3, as described below.

It will be appreciated that other means of separating a bag from the reel may be used, and such means will be apparent to those skilled in the art. For example, separation may be achieved by a cutting operation or by the application of a separation force generated other than by movement of the

feeding means between an operating and a retracted position, for example by a separate breaker bar.

In operation, the feeding means 1 of the present invention is positioned in front of a cheese tower 23 and above a conveyor 24 which conveys bagged cheese blocks to sealing apparatus.

Details of the holding means 2 in one embodiment are shown in Figures 6 to 9. A pair of clamp jaws 30 are movable by pneumatic cylinders 31 between an open position (as seen in Figures 6,8 and 9) and a closed position (as seen in Figure 7). Each jaw 30 may comprise a stainless steel plate. Inner horizontal surfaces of the frame 38 of the holding means 2 has a rubber-type compound surface 39 attached. Thus, in the open position the outer surface 37 of the jaws 30 clamp the edges of an open bag against the rubber surfaces 39 of the frame 38, providing a secure grip.

The holding means 2 may also include means for forming and holding the gusset in a bag after the bag has been filled and prior to sealing. Thus, on each side of the holding means there may be a filleted gusset arm 32 positioned substantially centrally between the clamp jaws 30 in their open position, so that the gusset arms 32 are extendable between the jaws 30 in their closed position (see Figure 7). Drive mean 33 are provided to move the filleted gusset arms 32 from a retracted position, as in Figure 6, to a gusseting (extended) position, as in Figure 7.

Means may be provided for spot welding a closed bag end to hold the gusseted formation. Thus, spot weld cylinders 34 may be provided above and beneath the holding means. The cylinders 34 drive spot weld elements 35, which are positioned so as to provide spot welding of the gusset on each side of a closed bag. The clamp jaws 30 may include cut away portions 36 to accommodate the spot weld elements 35. It will be appreciated that there are a variety of different means by which adjacent edges of the bag may be spot

welded together. For example, lasers could be used for plastics materials, and other mechanical or adhesive means may be applicable with different types of bag material. It will also be appreciated that the sealing means may provide more extensive or complete sealing of a closed bag, to obviate the need for sealing at a separate site.

Whilst the apparatus has been described with particular reference to the use of a gusseted plastics film web, and in relation to the packaging of cheese, it should be appreciated that the apparatus may be adapted for use with pre- gusseted webs of other material. Moreover, the invention is not limited to the packaging of cheese, but may be equally applicable to the packaging of any product in a gusseted bag.

The method of operation of the apparatus of the present invention will now be described with reference to the drawings.

With the feeding means 1 in its lower operating position the web 6 is fed about rollers 5 to engage in the rear end 18 of the web feeding jaws 7.

Each of the four edges of the gusseted film engages between the lip 8 and timing belt 9 of one of the four jaws 7.

Operation of the motor 12 drives the web forward along the jaws. At the same time cylinders 13 open the web feeding jaws 7 so that the web 6 is simultaneously fed and opened. Although it will be appreciated that the web could first be fed along the jaws and then the jaws opened. The open ends of the feeding jaws 7 are aligned with the holding means 2 and an opened bag end is continuously fed into the holding means 2 so that the clamp jaws 30 can securely trap the edges of the open web against the rubber surfaces 39 of the holding means frame 38.

The web feeding jaws 7 are then closed and the entire feeding means 1 is raised, drawing out the web 6 from the reel 3 until a perforation in the web is located just in front of the transverse members 16 of the clamping means.

The pneumatic cylinders 17 then close the clamping means to securely engage the web 6 behind the perforation. Continuing movement of the feeding means to its upper retracted position provides the retraction force necessary to separate the web along the perforation, leaving the bag engaged by the holding means 2, and the feeding means 1 clear of further operations in bag filling.

Any known system may be employed to correlate the positioning of the clamping means with the location of perforations in the web, for example the use of sensing means and identification features applied to the web in manufacture (e. g. the use of photo eye sensors and eye marks on the web).

A cheese block is then ejected from the cheese tower into the bag through the open end held by the clamp jaws 30. The filleted gusset arms 32 then engage with the gusseted sides of the bag whilst the clamp jaws 30 are closed, so that the gussets are properly formed in closing the end of the bag.

The simultaneous action of the clamp jaws 30 closing and the filleted gusset arms 32 engaging reforms the gussets.

The spot weld elements 35 are then engaged to provide welds between the two gusset layers on the outside edges of the folded gussets. A bagged cheese block can then be conveyed away along the conveyor 24 for subsequent sealing.

An alternative and preferred embodiment of the apparatus of the invention is shown in Figures 10 to 13. In this embodiment the holding means 41 is movable up and down. Otherwise the components of the apparatus are essentially unchanged from those described above. In operation, however, a bag opened by the feeding means 42 is fed continuously onto the clamp jaws 30 of the holding means 41 from the first operation of the motor which drives

the bag along the feeding means 42. Once the open bag end is clamped securely on the holding means 41 the whole of the holding means 41 is lowered until it is (as previously described) aligned with the outlet.

Simultaneously the feeding means 42 is raised. These movements, then provide the separation force to separate the bag from the web.

The apparatus of the present invention thus automatically dispenses, opens and holds open bags for filling with block product. In addition, separated and filled bags are automatically gusseted and spot welded ready for subsequent processing. There is thus no need for manual positioning, gusseting and transfer of bags. In addition, the ability of the apparatus to use reel-fed gusseted bags reduces manufacturing costs associated with supplying pre-cut and boxed bags. Furthermore, each bag on a web of pre-gusseted bags may have been automatically barcoded, avoiding the need for separate barcoding or identification of individual bags during the packaging process.

It is anticipated that apparatus of the present invention may be retrofitted to existing cheese factory cheese towers (or other packaging equipment) as well as becoming integral features of new equipment.

Where in the foregoing description, reference has been made to specific components or integers of the invention having known equivalents then such equivalents are herein incorporated as if individually set forth.

Although this invention has been described by way of example and with reference to possible embodiments thereof, it is to be understood that modifications or improvements may be made thereto without departing from the scope or spirit of the invention.