WO2008084263A1

WO2008084263A1 - Product handling

Info

Publication number: WO2008084263A1
Application number: PCT/GB2008/050024
Authority: WO
Inventors: Michael Webb
Original assignee: Quin Systems Ltd
Current assignee: Quin Systems Ltd
Priority date: 2007-01-12
Filing date: 2008-01-11
Publication date: 2008-07-17
Anticipated expiration: 2009-07-12
Also published as: GB2445556B; GB0700631D0; GB2445556A

Abstract

A product input station (2) has an input point (21). A track (5) follows a square path and connects input station (2) with a product output station (3). Two pairs of carriages (41 and 42) travel along track (5). Carriages (41) move in unison independently of carriages (42), which also move in unison. Input conveyor (22) delivers soft-pack products (6) sequentially to input point (21), where they are deposited upon carriage (41), which indexes whilst carriages (42) are stationary. At output station (3), a simple robot (31) grips a previously shingled group of products (6) from carriage (42)and places them into a packing case (71). The groups of products (6) are rapidly and efficiently turned through a right angle, between input station (2) and output station (3).

Description

PRODUCT HANDLING

The present invention relates to product handling and is concerned particularly, although not exclusively, with handling products in the form of soft packs or bags that are formed into groups.

There is a requirement for soft, flow-wrapped packs or bags to be accurately positioned, oriented and even shingled (slightly overlapped) together, prior to being picked and placed into a transport case. However, this type of pack is typically irregular in shape and centre of gravity and cannot easily be guided by simple mechanical guides. A general rule is not to touch the pack if at all possible, except by its driven medium. Any reorientation should only take place while the pack is static and completely held relative to the manipulator.

By orienting the direction of a supply of bags perpendicular to a pick-up conveyor, the pack direction can be changed for shingling and, by indexing the pick-up conveyor, the packs can be shingled. This is a simple method to use, but it does dictate that a downstream pick-and-place line has to be perpendicular to an upstream supply of packs from a wrapping machine.

Usually, a buffer is incorporated into an in-feed line such that a pick- and-place head (gripper) has time to pick up a group of packs whilst incoming packs are still being accumulated. This can be achieved in a number of ways - for example, by using two or three separate indexing belts or a 'race-track' system.

However, if a group of shingled packs needs to be rotated as a group, this typically has to be done by rotating a pick-up head whilst placing the packs into a case. The problem with rotating a pick-up head (typically part of a robot) is that the machinery for achieving this becomes both heavier and more complicated. There is an increasing requirement to pick and place packs into cases at much faster speeds, which is not helped by making the robot / gripper heavier. Also the pick-and-place head then requires connecting cables which, over prolonged use, can wear and cause problems

Preferred embodiments of the present invention aim to provide product handling apparatuses and methods that may be generally improved in the foregoing respects.

According to one aspect of the present invention, there is provided a product handling apparatus comprising:

a. a product input station having a product input point;

b. a product output station;

c. a track connecting said stations;

d. a plurality of carriages, each arranged to receive products at the product input point of the input station and to travel along the track to the output station; and

e. control means arranged to control the movement of the carriages along the track:

wherein:

f. the track forms a closed loop; and

g. the control means is arranged to provide relative indexing movement between a carriage and said product input point, when the carriage is at the product input station. Said product input station may comprise an input conveyor having an end at said product input point.

Preferably, said product output station comprises a pick-and-place robot arranged to pick products from a carriage at the product output station and place the picked products at a packing station.

Preferably, said pick-and-place robot is arranged to transport picked products without re-orienting the products relative to the robot.

An apparatus as above may further comprise transport means arranged to transport packing cases to and from said packing station; wherein said robot is arranged to place the picked products in said packing cases.

Said track may comprise a rail with which said carriages engage.

An apparatus as above may further comprise at least one drive belt or chain which follows said track and which engages said carriages.

At least two said drive belts or chains may be provided, each arranged to engage different ones of said carriages.

Preferably, said track describes a path which, in plan view, is polygonal.

Preferably, said track describes a path which, in plan view, is rectangular.

Said carriages may be arranged to co-operate with the track to follow the orientation of the track. An apparatus as above may further comprise guide means with which said carriages are arranged to co-operate to determine their orientation independently of the orientation of the track.

An apparatus as above may further comprise selection means whereby one or more of said carriages may have their orientation determined selectively, either by co-operation with the track or by co-operation with said guide means.

Preferably, each of said carriages is formed with a side portion that restrains products from radially outward movement when the carriage follows a turn on the track.

Each of said carriages may be formed with a recess arranged to receive said products.

Preferably, each of said carriages is provided with a high-friction surface arranged to receive said products.

Preferably, said carriages are arranged in at least two groups, the carriages of each group being capable of motion along said track, independently of the or each other group.

Preferably, said track is arranged in a rectangle and said input and output stations are arranged at respective sides of the rectangle that are orthogonal to one another.

An apparatus as above may comprise a plurality of said input stations.

An apparatus as above may comprise a plurality of said output stations. In another aspect, the invention provides a method of handling products, comprising the steps of:

a. delivering products to carriages at a product input point of a product input station; and

b. controlling movement of the carriages to cause them to travel along a track from the product input station to a product output station:

wherein:

c. the track forms a closed loop; and

d. relative indexing movement is provided between a carriage and said product input point, when the carriage is at the product input station.

Such a method may be carried out by means of an apparatus according to any of the preceding aspects of the invention.

Said products may comprise soft packs or bags.

Said packs or bags may be irregular in shape and/or centre of gravity.

A method as above may include the step of overlapping successive products as they are delivered to the carriages, thereby to form shingled groups of the products.

In the context of this specification, "track" means a path which carriages are constrained to follow. It may comprise a rail with which carriages engage, or any other suitable means. - S -

For a better understanding of the invention, and to show how embodiments of the same may be carried into effect, reference will now be made, by way of example, to the accompanying diagrammatic drawing, in which:

Figure 1 shows a product handling apparatus in plan view;

Figure 2 is a part cross-sectional view of one example of a carriage; and

Figure 3 is a part cross-sectional view of another example of a carriage.

The illustrated product handling system 1 comprises a product input station 2 having a product input point 21. A track 5 follows a generally square path with rounded corners, and connects the input station 2 with a product output station 3. Two pairs of carriages 41 and 42 are arranged to travel along the track 5. A first pair of carriages 41 is arranged to move in unison independently of the second pair of carriages 42, which are also arranged to move in unison. In an alternative arrangement, every carriage 41, 42 may move independently of the other carriages.

The track 5 may comprise any suitable means. For example, it may comprise a monorail, with wheels on the carriages 41, 42 engaging opposite sides of the rail. The monorail / wheels system then bears most of the lateral forces that arise. The carriages 41, 42 may be driven by chains or toothed belts that run below the track 5 and carry engagement means that extend upwardly and engage the carriages 41, 42. In the illustrated system 1, two such chains or belts may be provided one above the other - each chain or belt engaging a respective, different pair of carriages 41 or 42. Toothed pulleys for the chains or belts may be provided at the four corners of the track 5 and a respective servo motor may be provided to drive each chain or belt. Conveniently, a respective such servo motor may be provided at each of two corners of the track 5. Such chains or belts could serve in themselves as the track 5, although the provision of a monorail or alternative guide means may have the advantage of avoiding undue stresses in the chains or belts.

An input conveyor 22 delivers products 6 sequentially to the product input point 21, where they are deposited upon one of the carriages 41, 42. Figure 1 shows products 6 being deposited upon one of the first pair of carriages 41.

In this example, the products 6 are soft flow-wrapped packs or bags, which are typically of irregular shape and centre of gravity. As each successive product 6 is deposited upon the carriage 41, the carriage 41 is indexed to the left by a small distance, such that the next successive product 6 to arrive overlaps the previous product 6. The result is a group of packs 6 that overlap one another - that is to say, "shingled".

At the output station 3, a simple pick-and-place robot 31 is arranged to grip a shingled group of products 6 from the carriage 42 that is presently at the output station 3 and to move them to a packing station 7, where they are placed into a packing case 71. A packing case transporter 72 is arranged to transport packing cases 71 to and from the packing station 7.

A controller 8 controls overall operation of the product handling system

1 and, in particular, movement of the carriages 41, 42 on the track 5 and operation of the input conveyor 22, the robot 31 and the packing case transporter 72. In use, products 6 are assembled into shingled groups, as described above, on a carriage 41, 42 waiting at the input station 2. When a group is complete, all four carriages 41 , 42 are moved rapidly to the next station along the track. Upon completing this motion, the next carriage 41 , 42 to occupy the input station 2 begins to receive the next group of products 6, whilst the previously assembled group of product 6 is removed from the carriage 41, 42 that now occupies the output station. This type of motion may be referred to as a "race track" system.

In the illustrated example, after a carriage 41, 42 has left the output station 3, it occupies a first idle station 12 and then a second idle station 13, before re-entering the input station 2.

The carriages (41 as illustrated) that occupy the input station 2 and the first idle station 12 are indexed together to form a shingled group on the active carriage 41 at the input station 2, as described above. During this indexing movement, the other pair of carriages 42 that occupy the output station 3 and the second idle station 13 remains stationary.

At this time, the robot 31 places a gripper head 32 above the shingled group of products 6 in the active carriage 42, picks up the product group, rotates it until the head 32 is above the waiting packing case 71, and then places the shingled group into the packing case 71. Positioning of the product groups in the packing case 71 can be achieved by suitable control of the robot 31 and/or the packing case transporter 72. After placing a product group into the packing case 71, the robot 31 is rotated to its position with the gripper head 32 above the carriage 42, ready for the next carriage to come along. It will be appreciated that, in this way, successive products 6 may readily be formed into shingled groups and packed efficiently into packing cases 71. In particular, the illustrated system 1 lends itself well to high-speed use.

A particular feature of the illustrated system 1 is that the groups of products 6 are rapidly and efficiently turned through a right angle, prior to being picked up by the robot 31. Thus, the robot 31 can be of very simple and light construction, with no requirement for the gripper head 32 to rotate a product group that is held by the robot 31, as the robot itself rotates. Although the illustrated robot 31 is arranged for rotational movement, an alternative robot may be arranged for linear motion or any other desired motion.

As illustrated, the carriages 41, 42 follow the orientation of the track 5 as they travel along it. Thus, as noted above, the product groups in the carriages 41, 42 rotate through 90 degrees from one station to the next. In an alternative arrangement, the carriages 41, 42 may remain in fixed orientations, irrespective of the orientation of the track 5. For example, to achieve this, each carriage may have a lug 43 which engages a groove 51 formed in a baseplate 52 upon which the track 5 is mounted. It may be appreciated that the locus of the groove 51 may determine the orientation of the respective carriage 42, which may therefore remain in a fixed orientation, or may describe any desired sequence of orientations. Any suitable interengagement means may be provided between the carriages 41, 42 and either track 5 or baseplate 52 — for example, interengaging lugs and grooves as mentioned above, cams and cam tracks, etc.

Means may be provided for selectively changing the orientation of a carriage 41 , 42, between following the track 5 or fixed or other orientation. For example, the illustrated lug 43 may be moved between two positions in which it engages either with the baseplate 52 or the track 5. In another example, turning a carriage 41, 42 through 180 degrees may afford a selection between the carriage following either the track 5 or an alternative locus.

Preferably, the carriages 41, 42 have at least one side to restrict radial outward movement of the products 6 as a carriage travels around a corner. In Figure 2, a carriage 41, 42 is shown with two lateral side walls 44. In an alternative configuration as shown in Figure 3, a carriage 41, 42 has a trough or depression 45 to receive the products 6. Preferably, the upper surface 46 of the trough 45 is provided with a coating of a material having a high coefficient of friction, thereby to inhibit movement of the products 6 when in the carriage.

As noted above, movement of the carriages 41, 42 along the track 5 is controlled by the controller 8. Advantageously, the controller 8 may control the velocity and acceleration profiles of the carriages 41, 42 such that, as they travel around the corners of the track 5, radially outward forces and impulses are minimised.

The illustrated system 1 achieves the desirable object of avoiding contact between the products 6 and any component with which they describe relative motion, as the products 6 are moved from the input point 21 to the output station 3.

In the illustrated system 1, the output station 3 is the next station along the track from the input station 2. Thus, as mentioned above, the products 6 are rotated through 90 degrees when being transported from the input station 2 to the output station 3. However, if desired, the output station 3 may be disposed at the location of the first idle station 12. Thus, the products 6 would be in a similar though inverted orientation to that at the input station 2. This may suit an output line of a different orientation, a different type of pick-and-place robot 31, etc. Equally, the output station could be placed at the location of the second idle station 13.

The idle stations 12, 13 may be replaced by additional active input and output stations, similar to the input station 2 and the output station 3. Thus, productivity may be doubled.

We have found that a substantially square locus for the track 5 affords particularly efficient operation, with the track 5 and associated components occupying a small floor plan. However, it is possible to have a greater or lesser number of sides to the track, if desired. Also, although the illustrated track 5 has a generally rectangular configuration, it could alternatively follow a generally circular or ovoid locus, especially if the orientation of the carriages 41, 42 were controlled via the baseplate 52 or alternative means.

At the input station 2, operation of the input conveyor 22 may be controlled to provide a sequence of products 6 at regular intervals, to which indexing of the receiving carriage 41, 42 is synchronised. Alternatively, the products 6 may arrive on the conveyor 22 at irregular intervals and arrival at the input position 21 may trigger indexing of the waiting carriage 41, 42. Since the carriages 41 , 42 are arranged to move along the track 5, the simplest way to provide indexing with respect to the input point 21 is to move the carriages 41, 42 along the track in small increments. However, it is possible for the carriages 41, 42 to remain stationary at the input station 2 and for the delivery end of the conveyor 22 to be moved in small increments to provide the relative indexing motion.

In this specification, the verb "comprise" has its normal dictionary meaning, to denote non-exclusive inclusion. That is, use of the word "comprise" (or any of its derivatives) to include one feature or more, does not exclude the possibility of also including further features.

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings), may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

1. A product handling apparatus comprising:

a. a product input station having a product input point;

b. a product output station;

c. a track connecting said stations;

wherein:

f. the track forms a closed loop; and

g. the control means is arranged to provide relative indexing movement between a carriage and said product input point, when the carriage is at the product input station.

2. An apparatus according to claim 1, wherein said product input station comprises an input conveyor having an end at said product input point.

3. An apparatus according to claim 1 or 2, wherein said product output station comprises a pick-and-place robot arranged to pick products from a carriage at the product output station and place the picked products at a packing station.

4. An apparatus according to claim 3, wherein said pick-and-place robot is arranged to transport picked products without re-orienting the products relative to the robot.

5. An apparatus according to claim 3 or 4, further comprising transport means arranged to transport packing cases to and from said packing station; wherein said robot is arranged to place the picked products in said packing cases.

6. An apparatus according to any of the preceding claims, wherein said track comprises a rail with which said carriages engage.

7. An apparatus according to any of the preceding claims, further comprising at least one drive belt or chain which follows said track and which engages said carriages.

8. An apparatus according to claim 7, wherein at least two said drive belts or chains are provided, each arranged to engage different ones of said carriages.

9. An apparatus according to any of the preceding claims, wherein said track describes a path which, in plan view, is polygonal.

10. An apparatus according to any of the preceding claims, wherein said track describes a path which, in plan view, is rectangular.

11. An apparatus according to any of the preceding claims, wherein said carriages are arranged to co-operate with the track to follow the orientation of the track.

12. An apparatus according to any of the preceding claims, further comprising guide means with which said carriages are arranged to co-operate to determine their orientation independently of the orientation of the track.

13. An apparatus according to both of claims 11 and 12, further comprising selection means whereby one or more of said carriages may have their orientation determined selectively, either by co-operation with the track or by cooperation with said guide means.

14. An apparatus according to any of the preceding claims, wherein each of said carriages is formed with a side portion that restrains products from radially outward movement when the carriage follows a turn on the track.

15. An apparatus according to any of the preceding claims, wherein each of said carriages is formed with a recess arranged to receive said products.

16. An apparatus according to any of the preceding claims, wherein each of said carriages is provided with a high-friction surface arranged to receive said products.

17. An apparatus according to any of the preceding claims, wherein said carriages are arranged in at least two groups, the carriages of each group being capable of motion along said track, independently of the or each other group.

18. An apparatus according to any of the preceding claims, wherein said track is arranged in a rectangle and said input and output stations are arranged at respective sides of the rectangle that are orthogonal to one another.

19. An apparatus according to any of the preceding claims, comprising a plurality of said input stations.

20. An apparatus according to any of the preceding claims, comprising a plurality of said output stations.

21. A product handling apparatus substantially as hereinbefore described with reference to the accompanying drawing.

22. A method of handling products, comprising the steps of:

wherein:

c. the track forms a closed loop; and

23. A method according to claim 22, when carried out by means of an apparatus according to any of claims 1 to 21.

24. A method according to claim 22 or 23, wherein said products comprise soft packs or bags.

25. A method according to claim 24, wherein said packs or bags are irregular in shape and/or centre of gravity.

26. A method according to any of claims 22 to 25, including the step of overlapping successive products as they are delivered to the carriages, thereby to form shingled groups of the products.

27. A method of handling products, the method being substantially as hereinbefore described with reference to the accompanying drawing.