GB2576192A

GB2576192A - Product wrapping machine

Info

Publication number: GB2576192A
Application number: GB1812913.0A
Authority: GB
Inventors: Alan Francis Mann David; Neville Wright Lee
Original assignee: A M PACKAGING Ltd
Current assignee: A M PACKAGING Ltd
Priority date: 2018-08-08
Filing date: 2018-08-08
Publication date: 2020-02-12
Anticipated expiration: 2038-08-08
Also published as: GB2576192B; GB201812913D0

Abstract

A conveyor 1 has an endless driven surface and another surface not parallel to the first where each surface is inclined at at least 20° from the horizontal. Ideally the lowest edges of the conveyors are adjacent so that they form a V shaped longitudinal channel. They feed a wrapping station 12 which can have a base coplanar with to the endless driven surface and upstanding side walls. Ideally the other surface is also an endless belt, and the belts are both angled at at least 30° from the horizontal and 90° from each other. The belts can move collations of products 9 along a straight horizontal path. There could be supply conveyors 5, 6 parallel to the belts, a robotic arm associated with each supply conveyor to transfer items from the supply conveyor and collate them with other products 9 on the belts.

Description

This invention relates to a product wrapping machine and in particular to a machine arranged to wrap a collation of packets or bags, especially of snack foods and the like.

Background to the Invention

Snack foods are typically packaged in small, lightweight, bags or packets and it is common to supply collations of the bags or packets contained in a larger bag. The packing of the collations into the larger bag, typically achieved by forming the larger bag from film around the collation, involves a difficult balance between, on the one hand, minimising the volume of the packed larger bag, and on the other hand, minimising compression of the bags or packets to avoid damaging the snack foods.

Additionally, there is a need for flexibility in selecting collation sizes, as different customers may require different pack sizes.

One way to meet these requirements is set out in GB2512135, which discloses a packaging machine in which collations of packets are guided upright between vertical conveyor belts into a bag-forming section. This requires the packets - deformable bags - to be carried upright with their side edges in contact with the conveyors, requiring additional supports between the collations, which limits flexibility in changing pack sizes, because the additional supports need to be reconfigured at each change. Additionally, because of this alignment of the bags, changes in the number of bags in a pack affect only the length of the pack; other bag orientations are not possible.

It has been proposed to use an angled conveyor to convey collations generally towards a wrapping station, with a product manipulator for lifting each collation off the conveyor and on to a horizontal feed conveyor for the wrapping station. This arrangement has the disadvantages that the lifting of the collations carries with it the risk of packets being dropped and that additional supports are still required on the conveyor carrying the collations into the wrapping station, as described above.

- 2 Summary of the Invention

According to the invention, there is provided a product wrapping machine comprising a collating conveyor for receiving product collations and conveying the collations into a wrapping station having a channel therethrough with a base surface and opposed side surfaces upstanding therefrom in which a wrapping film is shaped and sealed around the collation, the collating conveyor comprising first and second conveying surfaces, at least the first of which is an endless driven surface, the surfaces being mounted so that the angle between them at any given point along their conveying length is substantially constant and is less than 180°, each surface making an angle with the horizontal of at least 20° at any given point along its length, characterised in that the base surface of the wrapping station is aligned with the first surface of the collating conveyor.

Preferably, the first surface makes an angle of at least 30° to the horizontal. In one embodiment, for use with generally rectangular product bags, the angle between the first and second surfaces is 90°.

While it might be possible to configure the second surface as a passive conveying surface formed of a low-friction material so that the collations of packets or bags slide freely along it, it is preferred to make both surfaces driven conveying surfaces moving in synchrony.

While the collating conveyor will typically be arranged to extend with the axis of movement of the collations in a straight line, and with that line horizontal, it would be possible for the axis to be angled to the horizontal and for the conveyor to be curved along its length vertically and or horizontally.

The machine preferably comprises a plurality of product supply conveyors extending alongside the collating conveyor and at least one product manipulator to lift products from the supply conveyors and place them on to the collating conveyor to form the collations. More preferably, each supply conveyor has a respective product manipulator.

The product wrapping machine of the invention is capable of wrapping a wide variety of product collations, with products stacked in different orientations, thus enabling the overall pack size to be optimised for the number of bags/packets it contains. This in turn enables the number of packs in a given

-3volume to be maximised, reducing the costs of shipping, storage and display space, as well as reducing the packaging costs.

Brief Description of the Drawings

In the drawings, which illustrate an exemplary embodiment of the invention:

Figure 1 is a perspective view of a product wrapping machine according to the invention;

Figure 2 is an end-on perspective view of the machine;

Figure 3 is a perspective view of the wrapping station forming part of the wrapping machine;

Figure 4 is a perspective view of a product gripper;

Figure 5 is an enlarged side view of the gripper shown in Figure 4;

Figure 6 is a simplified end view of the machine showing one way in which the grippers can place products on the conveyor;

Figure 7 is a view corresponding to that of Figure 6, showing an alternative way in which the grippers can place products on the conveyor; and

Figure 8 is an end view of the wrapping station of the packaging machine.

Detailed Description of the Illustrated Embodiment

Referring first to Figures 1 and 2, the packaging machine comprises an elongate collating conveyor having a first, segmented, driven conveyor surface 1 mounted with its surface in a plane approximately 30° to the horizontal and with a second driven belt conveyor surface 2 mounted so as to extend along the segmented conveyor with its surface in a plane at 90° to the driven conveyor surface 1 and synchronised with the movement of the first driven conveyor surface 1. The collating conveyor 1,2 extend between pairs of horizontal belt supply conveyors 3, 4, 5 and 6 through an extended collating stage 7 comprising four successive bays 7a-7d, in each of which is mounted a respective robotic product manipulator 8a-8d, described hereinafter in more detail with reference to Figures 4 to 8. Product packets or bags 9 arrive on the four supply conveyors 3-6, which may, for example, represent four different snack flavours, the manipulators 8a-8d lifting packets from the conveyors and placing them on to

-4the collating conveyor in predetermined groups or collations each comprising a mixture of packets containing different flavoured snacks, for example.

It will be appreciated that where more snack flavours are to be included in a collation, it would be possible to increase the number of supply conveyors accordingly and possibly the number of bays in the collating stage 7. Equally, where fewer snack flavours are required to be combined in each collation, one or two supply conveyors could remain unused, or carry the same flavours as another of the conveyors 3-6.

The collating conveyor 1, 2 extends from the collating stage 7 into a wrapping station 10, in which packaging film 11 is drawn from supply reels 12 and guided to form a tube around the collations, being separated into discrete multi-pack bags by a welding and cutting section 13, as may be seen more clearly from Figure 3. The film 11 is guided upwardly from under the collating conveyor 1, 2 at the point where that conveyor ends so that the collations of packets or bags 9 are fed on to the film 11, which is deflected through 90° from its feed direction through a forming stage 14 where, as the collations are deposited on to the film, the sides of the film are directed upwardly and over the collation so that the opposed edges of the film can be brought together and sealed in a welding station 15. Because the collating conveyor is tilted relative to the horizontal, the elements of the wrapping station 10 are similarly tilted so that, as the collations arrive in the forming stage 14 they will be supported by the moving film 11 on two faces of the collation, ensuring that the collation remains intact during wrapping. The collations emerge from the forming stage 14 on to the first 16 of a pair of wrapping stage endless conveyor belts, which conveys the collation through the welding and cutting section 13, where welding and cutting jaws seal the film tube between the collations, closing the second end of the pack for the collation that has just passed through the section 13 and the first end of the next collation. The second 17 of the pair of wrapping stage endless conveyors then carries the completed multipacks forward to deliver them to a packing station (not shown).

Figures 4 and 5 illustrate the lower end of one of the product manipulators 8a-8d. A triangular mounting element 40 is carried by three pairs of paral

- 5lelogram arms 41, 42, 43, each pair being connected to the mounting element 40 by respective ball joints 44. A gripper 45 is connected to a rotatable shaft 46 mounted in a bearing 47 in the element 40, which is rotatable by a pair of drive rods 48 through a universal coupling 49. The lower end of the shaft 46 carries a pivot mount 50 with a pneumatic motor 51 to permit pivoting of the gripper 45 about an axis perpendicular to the axis of the shaft 46. The gripper 45 has a suction head 45a selectively connectable to a reduced pressure source so as to be able to grip and release a product. As an alternative to suction grippers, mechanical grippers could be used to lift and place the products.

Figure 6 illustrates the formation of a collation of packets 9 stacked transversely of the first conveying surface 1, permitting a collation of multiple stacks to be formed, as shown in Figure 3, for example, where the collations consist of four stacks of six packets or bags. Alternatively, the packets 9 may be stacked in a direction normal to the first conveying surface 1, as shown in Figure 7.

Figure 8 shows the wrapping station 10 in which wrapping film is formed into a tube around the collation of packets 9 and then cut and sealed between collations by means of the welding and cutting section 13 in which welding jaws are brought together to close and seal the tube between successive collations, with a cutting blade severing the welded section of the tube to complete the sealing of one multipack and the closure of the forward end of the next multipack moving forward through the packaging machine. The otherwise conventional wrapping station is mounted so that its conveyors 13 and 17 make the same angle with the horizontal as the first conveyor surface of the collating conveyor 1,2. This means that there is no requirement to transfer the collations from the oblique collating conveyor to feed into the wrapping station, while also ensuring that additional support is not required to hold the collations together during the formation of the film tube around them. In this way, the speed of the machine can be maximised and change-over from one multipack size to another can be effected rapidly and with minimum operator intervention.

Claims

1. A product wrapping machine comprising a collating conveyor for receiving product collations and conveying the collations into a wrapping station having a channel therethrough with a base surface and opposed side surfaces upstanding therefrom in which a wrapping film is shaped and sealed around the collation, the collating conveyor comprising first and second conveying surfaces, at least the first of which is an endless driven surface, the surfaces being mounted so that the angle between them at any given point along their conveying length is substantially constant and is less than 180°, each surface making an angle with the horizontal of at least 20° at any given point along its length, characterised in that the base surface of the wrapping station is aligned with the first surface of the collating conveyor.

2. A product wrapping machine according to Claim 1, wherein the first surface makes an angle of at least 30° with the horizontal.

3. A product wrapping machine according to Claim 1 or 2, wherein the contained angle between the surfaces is 90°.

4. A product wrapping machine according to Claim 1,2 or 3, wherein the second surface comprises an endless belt drive.

5. A product wrapping machine according to any preceding claim, wherein the collating conveyor is configured to move the collations in a straight line.

6. A product wrapping machine according to any preceding claim, wherein the collating conveyor is configured to move the collations in a horizontal direction.

7. A product wrapping machine according to any preceding claim, comprising a plurality of product supply conveyors extending alongside the collating conveyor and at least one product manipulator is provided to lift products from the supply conveyors and place them on to the collating conveyor to form the collations.

8. A product wrapping machine according to Claim 7, comprising a respective product manipulator for each of the plurality of supply conveyors.