THE DELIVERY OF ARTICLES TO CONTAINERS

FIELD OF THE INVENTION The present invention relates to the delivery of articles, such as liners or absorbent pads, to containers such as trays.

BACKGROUND

In the packaging industry, the transfer of articles to containers is desirably done quickly to save both time and money. While the transfer of articles can be done manually, it is known that mechanical apparatus are quicker and more efficient. Some mechanical apparatus use a vacuum to transfer articles by means of suction to a suitably positioned container.

One apparatus that uses a vacuum to transfer articles has a vacuum applied to a plurality of suction caps. Each suction cap contacts the top surface of an article to collect and transfer it to a container. The article is suspended in the air for some distance before it is deposited into the container. The dispensing speeds of these apparatus are relatively low. Furthermore, in order to dispense the article into a container, the vacuum is separately interrupted, e.g. by a complex valving arrangement, to cause the article to drop off the suction cap.

SUMMARY OF THE INVENTION

In a first aspect, the invention provides a method of delivering an article to a container using an article transferrer, the method comprising the steps of: applying a vacuum to the article transferrer to induce a suction at the surface of the article transferrer; collecting an article when the article transferrer is in an article collection position by allowing said suction to suck the article to the surface of the article transferrer;

supporting the collected article from below during at least a part of the transfer of the article transferrer from the article collection position to an article delivery position; and delivering the article from the article transferrer via a delivery chute to the container when the article transferrer is in the article delivery position by at least partly interrupting the suction between the article transferrer and the article by allowing the delivery chute to pass therebetween.

In a second aspect there is provided an apparatus for delivering an article to a container, the apparatus including: an article transferrer rotatable between an article collection position and an article delivery position, the article transferrer being capable of having a vacuum applied thereto in order to induce a suction at the surface of the article transferrer to thereby collect an article when in the article collection position and the article transferrer being adapted to support the collected article from below during at least a part of the transfer of the article to the article delivery position; and a delivery chute for receiving the article from the article transferrer and delivering the article to the container; wherein, when the article transferrer is in the article delivery position, the delivery chute acts to at least partly physically interrupt suction between the article transferrer and the article by passing therebetween.

The presence of the delivery chute alleviates the need for the suction at the surface of the article transferrer to be separately interrupted e.g. by a valve arrangement. However, separate means for interrupting the vacuum at the surface may be provided in addition to instead of the delivery chute. Physically supporting the article on the article transferrer can improve the reliability of the apparatus.

In one embodiment, the article transferrer is a drum capable of rotating between at least the article collection position and the article delivery position. In another embodiment, the article transferrer is a drum rotatable through 360 degrees.

One or more apertures can be provided in the circumferential peripheral surface of the article transferrer. Suction can be induced at the, or each aperture, by evacuating a space inside the article transferrer. Alternatively, the vacuum is delivered by means of a passageway through the article transferrer. In one embodiment, the vacuum is delivered to the article transferrer along an axial support for the article transferrer. The axial support can be a stainless steel rod.

According to a third aspect of the invention there is provided an apparatus for transferring articles including: a rotatable article transferrer having axial end walls and a support surface extending between the axial end walls, the support surface having one or more apertures therein and one of the axial end walls having a passage to the one or more apertures for supplying a vacuum to the one or more apertures; a fixed end plate engaging with the said one of the axial end walls and adapted to have a vacuum applied thereto for supply via a plenum to said passage, the vacuum being supplied to the passage or interrupted according to the relative angular orientation of the article transferrer and the end plate.

The plenum may be formed on the end plate or on the said one of the axial end walls. When the latter is the case, the plenum will rotate with the article transferrer. In one embodiment, the vacuum is interrupted to the passage to coincide with the delivery chute passing between the article transferrer and the article.

In one embodiment, there is one aperture set arranged in one portion of the article transferrer surface so that, at any one time, only one pad is being collected/transferred or delivered. It is an option, however, that there is a second set of aperture(s) in another portion of the article transferrer surface to allow for a second article to be picked up while the first article is being transferred or delivered.

In one embodiment, the article delivered by the apparatus to a container is an absorbent pad. The absorbent pad may be the type used in the food packing industry to line containers such as trays prior to the insertion of food products such as meat or fish. These types of absorbent pads are used to keep food products fresh while in transportation or storage.

The apparatus can further include an article supply for supplying articles to the article transferrer when in the article collection position. The article supply can be a stacker for articles arranged adjacent to the article transferrer. The articles can be collected from the supply sequentially as required. Optionally, an article supply guide can be provided to prevent unwanted movement of the articles in the supply. The article supply guide may act to ensure only one article, such as the lower-most article, in the supply is collected at a time by the article transferrer.

The container may be passed to a delivery end of the delivery chute by a conveyor such as a conveyor belt. It is desirable that the time at which the article is delivered from the apparatus is controlled so as to be the same as the time at which a container is passing or is positioned at the end of the delivery chute. In order to control this timing a means can be provided for coordinating the conveying of the container to the delivery end of the delivery chute and the delivery of the article into the container. In one embodiment, the means includes a photo-electric eye for detecting the position of the container on the conveyor.

The invention also encompasses a tray to which an absorbent pad has been delivered by the apparatus according to the second or third aspects of the invention or by the method of the first aspect of the invention. Optionally, the apparatus is retrofitted to existing packaging equipment.

BRIEF DESCRIPTION OF THE FIGURES

Preferred embodiments of the invention will now be described with reference to the following drawings, which are intended to be exemplary only, and in which:

FIGURE 1 is a perspective view of the apparatus according to a preferred embodiment of the present invention;

FIGURES 2A to 2D are cross-sectional schematics of the apparatus of Figure 1 showing the steps involved in the collection, transfer and delivery of an article to a container;

FIGURE 3 is a perspective view of an article transferrer that can be used in the apparatus of the present invention;

FIGURE 4 is a perspective view of an embodiment of an end plate that can be used with the article transferrer of Figure 3; and

FIGURE 5 illustrates the apparatus of Figure 1 as part of packaging equipment.

DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

In Figure 1, apparatus 10 includes an article transferrer 12 disposed between an article supply 14 and a delivery chute 18. When in use, article transferrer 12 collects an article from supply 14 and transfers the article to delivery chute 18 down which the article is delivered to a container 22.

The articles in article supply 14 are stacked in supply chute 16. In Figure 1, the articles are shown as thin absorbent pads of the type used in the meat packing industry to line the bottom of a meat tray before meat is inserted into the tray for sale. One type of absorbent pad that is used to line trays is 110mm x 165mm and made from woven polyester and a laminate. However, it should be understood that the articles could be of any shape and could be made from any material provided they are capable of being collected, transferred and delivered to containers by the apparatus and method described below.

While article supply chute 16 is shown disposed at an angle with respect to article transferrer 12, the supply could arranged in any position, including vertically, provided the articles are capable of being collected from the supply by the transferrer, sequentially. In

one embodiment, although not a preferred embodiment, the articles are collected one by one rather than from a stack.

In Figure 1, article transferrer 12 is a drum having axial end walls and a support surface extending between the axial end walls. Article transferrer 12 is rotatable about an axis in the direction of the arrow shown. The inside of drum 12 is machined out so that a space or passage is formed in the drum (i.e. not solid). A vacuum is generated in the space by means of a vacuum pump (not shown). In one embodiment, a 1.5 hp vacuum pump is used to generate an 80 mbar vacuum which is piped via a flexible hose (not shown) to the drum via an in-line filter and a hollow drum axle 17. The axle 17 may be formed of stainless steel. There is at least one aperture 20 in or on the circumferential periphery of the drum and the vacuum applied to the drum is capable of inducing suction at the aperture(s) in the surface of drum 12.

The time and speed of the rotation of drum 12 is controllable. In one embodiment, the drum is controlled by a variable speed drive, such as an electrical motor and a gearbox. It is an option that only the outer periphery of the drum is rotatable while the centre portion of the drum remains fixed. It is also an option that the drum is not rotatable through 360 degrees. Thus it might only be rotatable between the pad supply 14 and the delivery chute 18.

The drum can be made from any material provided it is rotatable and is capable of having a vacuum applied thereto. When used in the food industry, the drum can be made from food grade acetyl. If desired, the drum may have surface undulations provided these do not adversely affect its use as an article transferrer as described.

It should be understood that while a drum is the preferred article transferrer, other elements capable of supporting and transferring articles are within the scope of the invention. For example, the article transferrer might have a hemi-spherical cross-section with a movable surface portion which acts in substantially the same way as the drum described below.

In Figure 1, two apertures or slots 20 are shown on the circumferential peripheral surface of drum 12 (the support surface). Figure 2A shows that when apertures 20 are positioned to contact an absorbent pad at the base of supply 14, the pad is collected by being attracted to (or sucked to) the surface of drum 12 by the suction at the surface induced by the vacuum.

While two apertures are shown in Figure 1 , any number of apertures could be provided on the support surface of the drum provided the suction induced at the surface is sufficient to collect an absorbent pad from supply 14. Optionally, there is a plurality of small apertures adjacent to one another rather than a slot. In one embodiment, the apertures are only arranged in one portion of the drum surface so that, at any one time, only one pad is being collected/transferred or delivered. It is an option, however, that there is a second set of aperture(s) in another portion of the drum surface (for example, on the opposite side of the drum and screened from view in Figure 1). If more than one set of apertures is provided, a first pad may be collected by one set of apertures while, for example, a second pad is transferred by another set of apertures at the same time.

The width, length, and number of apertures in the drum surface can be chosen with regard to the material type and size of the pad or other article being collected, transferred and delivered. When the articles are absorbent pads of 1 1 Omm x 165mm and non woven polyester and a laminate (as above) there are two slots in the drum surface preferably, of 6mm x 40mm.

In the packaging industry, often the pad-type for delivery changes during a packaging shift. For example, 100 of a first type of absorbent pad might be delivered to a first tray type, followed by 100 of a second type of absorbent pad being delivered to a second tray type. It is an option that the drum-part of the apparatus is inter-changeable to allow a first drum having a first aperture set to be used with a first type of absorbent pads and a second drum having a second, different aperture set to be used when delivering the second type of absorbent pads. Drum 12 might have quick-connect fittings (not shown) to allow for the change of a drum during a packaging shift.

As drum 12 rotates, the pad held to the support surface by suction moves with the drum (Figure 2B). Since the pad is supported by the drum from below or underneath during at least a part of its transfer, the suction required to hold it in place may be less than if the pad were held from the top and suspended. In one embodiment, the width of drum 12 is larger than the pad being transferred and delivered, to increase the surface area of the pad that is supported during transfer.

It is an option that the apparatus having an article supply further includes an article supply guide 23 on the article supply to ensure that the pad(s) are guided to the drum. The article supply guide can also be used to ensure that pad(s) adjacent to the pad collected are not able to inadvertently move from supply chute 16 as the lower-most pad is collected by the drum. In one embodiment, the article supply guide is a brush having bristles stiff-enough to prevent unwanted movement of the pads in the supply. However, any means of preventing unwanted movement of the pads could be provided e.g. a plastic barrier disposed so as to allow one pad to be collected and to prevent others from moving. In some instances, (depending upon the nature of the articles delivered) article supply guide 23 may not be needed, for example, if there is a low likelihood that the articles in the supply chute will move inadvertently.

Once collected from the article supply, when the drum is in the article collection position, the pad is rotated with drum 12 to an article delivery position. When in this position, delivery chute 18 passes between the pad and the drum thereby at least partly physically interrupting suction holding the pad to the surface of the drum (Figure 2C). As the suction connection is broken, the pad is released from the drum and slides down the inclined delivery chute 18. The pad is delivered to container 22 from a delivery end of chute 18.

In one embodiment, suction at the drum surface is not interrupted except by the delivery chute. In another embodiment, drum 12 has an end plate assembly through which the vacuum is delivered to a vacuum passage in the drum from the drum axle 17. The end

plate assembly is arranged in such a way that it at least partly blocks vacuum flow to the apertures in the drum as the drum rotates.

Figure 3 is a side view of drum 12 connected to axle 17 and Figure 4 is a view of end plate assembly 11. End plate assembly 11 is mounted on the drum axle 17 and engages an end wall of the drum shown in Figure 3. End plate assembly 11 is fixed rotationally, that is the axle 17 and drum 12 rotate relative to it. The end plate has an arcuate plenum portion 111 and a part-annular vacuum groove 112. As seen in Figure 4, plenum portion 111 is effectively an extension of vacuum groove 112 that completes the annulus and extends radially outwards of the line of groove 112.

When the vacuum pump is operating, a permanent vacuum is created in plenum 11 1 and groove 112 via one or more openings in the end wall of drum 12 shown in Figure 3 as an annular array of openings 13. The vacuum induced in the plenum and groove of the end plate can be further delivered to the aperture(s) 20, by means of a vacuum passage 15 in the end wall of the drum. The end plate is configured so that the vacuum can only pass to the apertures via passage 15 when the vacuum passage is aligned with the plenum 111. Seals 113a and 113b define the ends of plenum 111. By way of example as the drum rotates (clockwise) over seal 113a, vacuum passage 15 passes into alignment with the plenum and suction at the apertures is introduced. As the drum continues its rotation, vacuum passage 15 passes over seal 113b and out of alignment with the plenum, thereby causing the vacuum at the apertures to be interrupted or cease. Effectively, the vacuum is supplied to the passage or interrupted according to the relative angular orientation of the article transferrer and end plate. The vacuum delivered to the apertures is initially blocked or interrupted to coincide with the drum apertures being in the article delivery position adjacent the delivery chute 18. This combination with the delivery chute vacuum interruption allows improved pad dispensing at a higher speed without turning the vacuum pump on and off.

Once the pad is delivered to container 22 (Figure 2D), the padded container 22a moves away from the apparatus and a new, empty container is moved into position. Drum 12

(now having no pad attached) moves from the delivery position back to article collection position, i.e. to the article supply 14 in order to collect another pad. This process is repeated as many times as desired to fill a number of containers. In order to collect another pad, the drum might continue on its path of rotation from the delivery position back to supply 14 (thereby completing one full 360 degree revolution as shown in Figure 2D) or the drum might retrace a partial rotation back to the supply.

Container 22 is a tray having dimensions complementary to the absorbent pad delivered to it. An example of a tray which could be used with the apparatus is 165mm and 225mm and a depth of between 30 to 80 mm. It should be understood that the container type will alter depending upon the article delivered. For example, if the article is a food item, a box with a lid might be the preferred container.

In one embodiment, the trays supplied to the apparatus 10 are passed to the apparatus from a stacked tray supply which is destacked or denested by a denester apparatus 30. The trays 22, once denested, are passed along a conveyor 24. In one embodiment, the conveyor is a conveyor belt made from 316 stainless steel and having a food grade Interlox belt.

The time at which pads are delivered from apparatus 10 is controlled so as to be in time with an approaching tray. This gives some flexibility in the process so that pads do not pile up on the conveyor if there are no trays in position (for example when the supply of trays is being restocked). The flow of the trays need not be interrupted by any part of the process and the apparatus may work according to the tray delivery speed. Accordingly, the system may not need to be stopped as frequently as with prior art arrangements.

In order to deliver a pad in time with an approaching tray, there is provided a means for coordinating the conveying of the container to the delivery end of the delivery chute and the delivery of the article to the container. This may include a photo-electric eye for detecting the position of the container on the conveyor, e.g. the photo-electric eye (not shown) can detect when a tray is approaching the end of chute 18 along conveyor 24. The pad is held by the drum just above the delivery chute 18 and, as tray 22 moves into

position, the mechanisms which control the rotation of the drum cause the drum to rotate to the delivery position. In the delivery position, the suction connection between the pad and the drum is broken and the pad is delivered to the passing tray via the delivery chute 18. The rotation of the drum may be increased to dispense the pad and decreased when picking up a pad.

Figure 5 shows apparatus 10 in combination with a denester apparatus 30. The packaging equipment 40 has a small foot-print (e.g. 625 mm width, 2000 mm length). When in use, an operator places a stack of rigid trays 22 into denester 30 and a stack of absorbent pads into pad supply chute 16 before pressing the "Start" button. The denester automatically denests trays onto the transfer conveyor 24 via scroll denesters 26. The trays 22 are conveyed in the direction of the arrows shown in Figure 3 to apparatus 10. As each tray passes beneath the end of delivery chute 18, a pad is delivered to the tray. Padded trays are conveyor away from apparatus 10 and might continue on other conveyors (not shown) to be filled with a product such as meat.

When the number of trays in denester 30 is low, the equipment stops automatically and pads cease to be delivered from apparatus 10. Once a new supply of trays is manually loaded the equipment restarts automatically.

The present apparatus may have fewer moving parts; a greater surface area in contact with the pads; and a delivery speed approximately 30 % greater (up to 60 pads per minute (ppm)) compared with prior arrangements. Furthermore, the apparatus minimises labour requirements since it requires low maintenance and is easy to use. The apparatus can be retro-fitted to an existing piece of equipment if desired.

Those skilled in the art will appreciate that the invention described herein is susceptible to variations and modifications other than those specifically described. It is to be understood that the invention includes all such variations and modifications which fall within its spirit and scope.

Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

The reference to any prior art in this specification is not, and should not be taken as, an acknowledgment or any form of suggestion that that prior art forms part of the common general knowledge.