IMPROVEMENTS IN AND RELATING TO PACKAGING APPARATUS

FIELD OF THE INVENTION

The present invention relates to packaging apparatus, film supply apparatus for packaging apparatus, tray advancing apparatus for packaging apparatus, packaging methods and kits of parts for packaging apparatus.

BACKGROUND TO THE INVENTION

Known packaging apparatus which can be used to seal film to trays is provided with a film supply from which a film sheet can be drawn into a sealing station. In the sealing station the film is sealed to a tray and the part sealed to the tray is cut from the remainder of the sheet. The remnants of the film sheet are then drawn out of the sealing station using a rewind apparatus. The rewind apparatus also draws more film from the film supply into the sealing station in preparation for the next sealing process .

So that the rewind apparatus can draw fresh film into the sealing station some part of the film sheet must be left intact after the part sealed to the tray is cut from it. To ensure that film can be drawn through the sealing station it is therefore typical for the film sheet to be dimensioned to be wider than the tray to which it is to be sealed. This leaves a connection between the film on the rewind apparatus and the film on the film supply.

To minimise the risk of the film snapping, which prevents fresh film from being drawn into the sealing station and

requires the sealing process to be halted for the film to be reset, it is typical to use a significant excess of film. However, the use of excess film is inefficient in terms of film wastage and the alternative of using minimal excess film but having to reset the packaging apparatus when the film snaps is also inefficient and undesirable.

Accordingly, it is an aim of a preferred embodiment of the present invention to address problems associated with known packaging apparatus whether identified herein or otherwise .

SUMMARY OF INVENTION

According to a first aspect of the present invention, there is provided a packaging apparatus for sealing film to a tray, the packaging apparatus comprising: a film supply means for holding a supply of film; a sealing means for sealing film to a tray; and a tray advancing means for moving a tray; wherein, in use, the sealing means is arranged to seal film to a tray and the tray advancing means is arranged to move said tray with the film sealed thereto such that movement of said tray draws film from the film supply means.

Suitably, the apparatus comprises a sealing station comprising sealing means. Suitably, the sealing station further comprises cutting means for cutting the film.

Suitably, the apparatus comprises a sealing station having sealing means for sealing film to a plurality of trays and cutting means for cutting film between adjacent trays.

Suitably, the sealing station is arranged to seal film to a plurality of trays and then cut the film between the trays without moving the trays between the sealing and cutting steps.

Suitably, the apparatus comprises a sealing station comprising sealing means and cutting means wherein, in use, the sealing means is arranged to seal film to a plurality of trays and the cutting means is arranged to cut the film between adjacent trays and leave film trailing from the most upstream sealed tray back to the film supply means and the tray advancing means is arranged to move the trays such that movement of the most upstream sealed tray draws film from the film supply means. Suitably, the sealing means is arranged to seal film to a plurality of trays to form sealed containers.

Suitably, the tray advancing means is arranged to advance a plurality of trays. Suitably, the tray advancing means is arranged to advance trays in groups.

Suitably the tray advancing means is arranged to advance trays in groups and is arranged to group trays such that a tray which is the trailing tray of a group in one cycle of operation of the apparatus becomes the lead tray of the next group in the next cycle of operation of the apparatus .

Suitably the tray advancing means is arranged to advance trays in groups and is arranged such that the tray which is moved to draw film from the film supply means (drawing tray) is the lead tray of a group. Suitably, the

advancing means is arranged to advance unsealed trays at the same time as it draws film from the film supply means. Suitably, as the drawing tray is advanced it causes film to be pulled over unsealed trays in the group which it leads .

Suitably, the tray which is moved to draw film from the film supply means (drawing tray) is the trailing tray of a group of sealed trays and the lead tray of a group in which the remaining trays are unsealed. Suitably, during the advancing operation the group of sealed trays is moved apart from the drawing tray and the group of unsealed trays is moved towards the drawing tray.

Suitably, the tray advancing means comprises a tray advancing apparatus arranged to collect trays from a conveyor. Suitably, the tray advancing means comprises a tray advancing apparatus arranged to deliver trays to a conveyor. Suitably, the packaging apparatus comprises first and second conveyors interposed by a tray advancing apparatus .

Suitably, the tray advancing means comprises a tray advancing apparatus comprising a tray advancing member, preferably two tray advancing members, for engaging a tray having film trailing there from back to a film supply means and moving said tray to draw film from said film supply means .

Suitably, the tray advancing apparatus comprises two tray advancing members for engaging either side of a tray.

The tray advancing apparatus suitably includes one or preferably two advancing members and a tray support surface which is arranged to support a tray as it is moved by the advancing member or members. The tray support surface suitably interposes first and second conveyors. Suitably, the advancing member or members are arranged to slide the tray over the support surface.

Suitably, the film supply means comprises a film supply apparatus. Suitably, the film supply means comprises a film source comprising a supply of film from which film can be drawn.

The film source may be any suitable film source including a film reel comprising a roll of film rotatable about a spindle. Suitably, the film comprises materials such as Polyester (PET) , Nylon (OPA) , Polypropylene (OPP) .

The film may typically have a thickness of between 14 - 100 micron, although other thicknesses may be used. The film may have a thickness of 20 micron or less, for example 15 micron or less, for example 14 micron.

Suitably, the tray comprises a metal or plastics tray. The tray may be manufactured from materials such as Polypropylene (PP) , Crystallised polyester terephthalate (C-PET) , Amorphous polyester terephthalate (A-PET) , Polyvinyl chloride (PVC), High impact polystyrene (HIPS), High density polyethylene (HDPE) and Aluminium foil.

Suitably, the film has a width substantially corresponding to the width of the trays to be sealed.

Suitably, the film supply means comprises a film feeder arranged to hold a temporary store of film downstream of the film source. Suitably, the film supply means comprises a film feeder arranged to draw film from a film source to create a temporary store of film.

Suitably, the apparatus is arranged such that film is fed towards the sealing means from a film feeder rather than directly from the film source. Suitably, the film feeder draws a predetermined amount of film from the film source. Suitably, film is drawn from the film source and/or the film feeder by moving a tray to which film is sealed.

Suitably, the film feeder comprises a body to which a feeder arm is mounted such that it can cause film to be drawn from a film source. Suitably, the feeder comprises a first and a second body member to which one or two, preferably two, feeder arms are pivotally mounted such that they can cause film to be drawn from a film source. Suitably, the or each feeder arm is moveable between an open and a closed position. Suitably, in use, the or each feeder arm is moved from the open position to the closed position as film is drawn from the film feeder by moving a tray. Suitably, in use, when the or each feeder arm is moved from the closed position to the open position, film is drawn from the film source to be temporarily stored in the feeder. Suitably, the or each arm is biased towards the open position. The or each arm may be biased towards the open position by gravity. A counter balance may be provided to reduce the bias to control tensioning in the film and restrict any over or under tensioning. The apparatus may comprise a main counter balance mounted to the arm or arms on one side of a pivot to partially

counter the weight of the arm(s) and guides on the other side of the pivot and an adjustable counterbalance for making fine adjustments to the biasing of the arm(s) .

Suitably, the film feeder comprises a plurality of guides. Suitably one or more of the guides comprises a roller, for example each guide may comprise a roller. Suitably, film lying between the film source and the sealing station is arranged to pass around said guides. Suitably, the guides are arranged along the film feeder to provide a temporary storage means for film drawn from the film source.

Suitably, the feeder body carries a plurality of guides. Suitably, a plurality of guides are arranged to extend between the first body member and the second body member.

Suitably, a feeder arm carries a plurality of guides. Suitably, the film feeder comprises first and second arms and a plurality of guides are arranged to extend between the first and second arms.

Suitably, guides are arranged along the feeder body and arm in an alternating pattern. In use the feeder arm or arms can be positioned in a closed position with the feeder arm guides lying close to the feeder body guides with the film passing around the guides in a zig-zag pattern. The feeder arm or arms may then be moved to an open position in which the feeder arm guides lie further from the feeder body guides such that film is drawn around the guides in an enlarged zig-zag pattern.

Suitably, the film supply means comprises a pickup roller for selectively drawing film from the film source.

Suitably, the film supply means further comprises a nip- roller which works together with the pickup roller to draw film from the film source. Suitably, the pickup roller and suitably also the nip roller are positioned between the film source and the film feeder. Suitably, the pickup roller comprises a motor to rotate the roller to draw film from the film source. Suitably, the operation of the pickup roller and suitably also the nip roller are controlled by the position of a feeder arm.

Suitably, in use, if a feeder arm is in the open position, the motor is switched off. Suitably, in use, the pick up roller is switched on as a feeder arm is moved from an open position.

Suitably, in use, the motor is switched on or off when a feeder arm reaches a predetermined position. Suitably, the motor is switched on when a feeder arm moves from an open position. Suitably the motor remains on as the arm moves to a closed position but if the arm reaches a fully closed position the motor is stopped. This may allow the motor to be stopped automatically if there is a film jam which has caused the arm to move to a fully closed position .

Suitably, the film supply means comprises a film stopper for selectively holding the film at a point between the film feeder and the sealing station. Suitably, the film supply means comprises a film stopper for stopping film downstream of the stopper from being moved by movement of the feeder arm. This may prevent a tray to which film extending from the film supply means is sealed experiencing a force tending to pull it upstream when the

feeder arm is moved. This may allow the tray advancing means to disengage the tray during a sealing operation. Suitably, the film stopper comprises an aperture through which film passes and which can be selectively opened and closed. Suitably, the film stopper comprises a stopper guide and a stopper plate and the aperture is a slit between the stopper guide and the stopper plate. Suitably, the stopper plate is moveable relative to the stopper guide to selectively open and close the aperture. Suitably, the stopper guide comprises a roller.

Suitably, in use, if the aperture is open, film can be drawn from the film feeder by moving the tray. Suitably, the apparatus is arranged such that when the feeder arm is moving from the open position towards the closed position, the aperture is open. Suitably, the apparatus is arranged such that when the feeder arm is moving from the closed position towards the open position, the aperture is closed. Suitably, the aperture is only closed when the advancing means reaches an advanced position. Suitably, when the advancing means reaches an advanced position it triggers the stopper to be closed.

The apparatus may comprise a film guider for aligning film with a tray. The film supply means may comprise said film guider. The film guider may ensure the edges of the film align with the edges of the tray. The film guider may cause the film to contact the top of the tray.

Suitably, the tray advancing means comprises a tray advancing apparatus. Suitably, the tray advancing means comprises a tray advancing member, preferably two members, for engaging and moving a tray. Suitably, the tray

advancing means comprises two tray advancing members for engaging either side of a tray. The or each advancing member suitably comprises an advancing arm. Suitably, the tray advancing means comprises a first and a second tray advancing arm. Suitably, the tray advancing arms are moveable to move a tray and draw film from the film supply means. Suitably, the advancing arms are aligned with one another and arranged to move in tandem with one another.

Suitably, the tray advancing means comprises a driving means to which the tray advancing member or members are connected. Suitably, the driving means comprises a drive motor for moving the tray advancing member or members. Suitably, the driving means comprises a track for guiding the movement of the tray advancing member or members. Suitably, the drive motor and the track are configured to move and guide first and second tray advancing arms.

Suitably, the tray advancing means is arranged to define a bay in which a tray can be accommodated so as to be moved by the tray advancing means. Suitably, the tray advancing means is arranged to define a plurality of bays in which trays can be accommodated so as to be moved by the tray advancing means. Suitably, the tray advancing means comprises an elongate bay which is elongate in comparison to bays upstream and downstream of said elongate bay. Suitably, said elongate bay comprises a central bay. Suitably, the tray advancing means comprises an equal number of bays upstream and downstream of the central bay. Suitably, the apparatus is arranged such that, in use, a tray having film extending from the film supply means sealed thereto is located in the elongate bay. Suitably, the bays are defined by the tray advancing arm or arms.

Suitably, each one of the tray advancing arms comprises a stem from which fingers extend. Suitably, the fingers are arranged to selectively engage with a tray. Suitably, the tray advancing arms are positioned so that the fingers on the first and second tray advancing arms extend towards each other.

Suitably, a bay is formed between adjacent fingers for accommodating a tray. Suitably, the arms have several fingers arranged down their length to form a number of bays each for accommodating a tray.

Suitably, the advancing arm or arms are arranged to advance several trays and have a plurality of bays. Suitably, the bay arranged to accommodate a lead tray, in use, is elongated in comparison to the other bays.

Suitably, the advancing arms comprise equally spaced fingers to form equal sized bays with the exception of a central bay which may be elongate. Suitably, the trailing finger on each advancing arm is shorter than the remaining fingers and may comprise a tapered section. This construction of trailing finger may minimise the risk of the fingers damaging a tray.

Suitably, the sealing means comprises a sealing apparatus. The sealing apparatus may comprise heating means .

Suitably, the sealing means is arranged to simultaneously seal film to a plurality of trays. Suitably, the sealing means comprises a press having a plurality of press parts

each arranged to engage a tray. Suitably, the sealing means comprises heated press parts. Suitably, the sealing means comprises a plurality of press parts and an unheated press part with the most downstream press part being unheated and the remaining parts being heated.

In use, a film may be sealed to a tray by a heated press part when it is a trailing tray and after it is sealed and advanced to become a lead tray the tray may be engaged by the unheated press part whilst film is sealed to trailing trays by the heated press parts. This press arrangement may hold the lead tray in position to ensure the film trailing from the lead tray is correctly positioned over trailing trays whilst avoiding wasting energy reheating the seal on the lead tray.

Suitably, the sealing means comprises an upper press section positioned, in use, above the trays and film and a lower press section comprising a tray locator positioned, in use, below the trays. The tray locator is suitably arranged to move upwards such that the trays pass into apertures defined by the locator with their rims supported so that the trays can then be raised towards the upper press section and the film can be pressed between the trays and the upper press section.

The apparatus may be arranged to seal film to trays of varying sizes. The advancing members and press sections may be removable so that different parts may be used with different size trays.

The sealing means may further comprise a cutting apparatus. The packaging apparatus may comprise sealing

and cutting apparatus which may be provided at a sealing station .

Suitably, the packaging apparatus comprises a sealing station for sealing the film to trays and cutting the film between trays .

Suitably, the tray advancing means moves a tray to the sealing station for film to be sealed to said tray and through the sealing station to draw film from the film supply means .

The packaging apparatus may be such that with a new supply of film it is necessary to perform a set up step after which the apparatus may operate on a repetitive automated cycle. The set up step may comprise an operator drawing film such that it extends through the sealing means and then operating the packaging apparatus to position a tray under the sealing means with film laid over the tray and sealing film to the tray such that film extends back from the tray to the film supply means. The tray from which film extends back may then act as a drawing tray to draw film from the film supply means when it is moved.

The set up step may comprise an operator drawing film such that it extends through the sealing means and then operating the packaging apparatus to position a group of trays under the sealing means with film laid over the trays and sealing film to the trays such that film extends back from the trailing tray of the group to the film supply means. Suitably, the trailing tray may then be grouped with a trailing group of trays such that it becomes the lead tray of that group.

Suitably the tray advancing means is arranged to move a lead tray along with at least one trailing tray through the sealing station. The film drawn into the sealing station by the lead tray may be laid over the or each trailing tray and sealed thereto. Suitably, the sealing station comprises a cutting means for cutting the film between the trays but which is arranged to leave the film uncut behind the trailing edge of the last trailing tray. Suitably a cutting means is provided between each press part. Suitably, the advancing means is arranged such that it then repositions itself such that the last trailing tray becomes the lead tray of the next cycle of operation. The advancing means is suitably arranged such that when it moves the new lead tray along with at least one new trailing tray through the sealing station it moves the former lead tray and the trays between that former lead tray and the new tray from the sealing station.

Suitably, the tray advancing means moves in a cyclical repetitive motion and uses a first and subsequent lead trays to advance film from the film supply means.

Suitably, the apparatus is arranged to perform an end sequence once the last of the trays to be sealed has passed to the sealing means. Suitably, the end sequence is such that trays in the sealing station are sealed and then advanced such that all trays are removed from the sealing station and the film extending from the film supply means is no longer connected to any of the trays.

The end sequence may vary depending on how many trays are in the last group to enter the sealing station but a

suitable sequence for any situation may comprise a three cycle sequence as follows: (i) the advancing means moves to its advanced position bringing a last group of trays into the sealing station and then disengages them after which the sealing means performs a sealing and cutting operation; (ii) the advancing means returns to reengage the trays and moves to its advanced position carrying some (or all) trays from the sealing station and then disengages the trays after which the sealing means performs a sealing and cutting operation; (iii) the advancing means returns to reengage the remaining tray (if one remains) and moves to its advanced position carrying the tray (if present) from the sealing station and then disengages the tray (if present) but in this cycle the sealing means does not perform a sealing and cutting operation .

Suitably, the packaging apparatus comprises a first endless conveyor to move a tray towards the sealing means. Suitably, the packaging apparatus comprises a second endless conveyor to move a tray away from the sealing means. Suitably, the trays are moved from the first endless conveyor and deposited onto the second endless conveyor by the tray advancing means .

Suitably, the apparatus comprises continuously moving first and/or second conveyors. Suitably, the apparatus comprises a gate to control travel of trays along the first conveyor. The gate may ensure trays can only pass a certain point when the advancing means is ready to collect them. The gate may thus hold trays back such that they ride over the conveyor as it moves. The gate may also ensure trays can only pass a certain point once enough

trays are in place to be collected by the advancing means. Opening and closing of the gate may be controlled by the position of the advancing means and/or a sensor which detects trays as they pass on the conveyor.

The packaging apparatus may comprise an optional rewind roller. This may allow the apparatus to draw film with a rewind roller in substantially the same manner as known apparatus as an alternative to drawing it by movement of a tray.

The packaging apparatus may comprise any feature as described in relation to a preferred embodiment of the invention under the heading "detailed description of the invention".

According to a second aspect of the present invention, there is provided a film supply apparatus for use with a packaging apparatus, wherein the film supply apparatus comprises a film feeder which comprises means for forming a temporary store of film from a film supply such that film can be supplied to a sealing means of the packaging apparatus from said temporary store.

Suitably, the film supply apparatus is arranged such that film can be supplied to a sealing station of the packaging apparatus from said temporary store.

Suitably, the film feeder comprises a film feeder as described in relation to the first aspect.

Suitably the film supply apparatus comprises any feature as described in relation to the film supply apparatus and/or film supply means of the first aspect.

Suitably the packaging machine comprises any feature as described in relation to the first aspect.

According to a third aspect of the present invention there is provided a tray advancing apparatus for a packaging apparatus, wherein the tray advancing apparatus comprises a tray advancing member for engaging a tray having film trailing there from back to a film supply means and moving said tray to draw film from said film supply means.

Suitably, the tray advancing apparatus comprises two tray advancing members for engaging either side of a tray.

Suitably, the tray advancing apparatus comprises a tray advancing apparatus as described in relation to the first aspect.

Suitably the tray advancing apparatus comprises any feature as described in relation to the tray advancing means of the first aspect.

Suitably the packaging machine comprises any feature as described in relation to the first aspect.

According to a fourth aspect of the present invention, there is provided a method of packaging using a packaging apparatus the method comprising the steps of:

sealing a film sheet to a tray with sealing means such that film extends back from the tray to a film supply means; and subsequently moving the tray with tray advancing means so as to cause film to be drawn from the film supply means.

Suitably, the method comprises locating further trays such that film drawn from the film supply means when the advancing means moves the tray can then be sealed to those further trays.

Suitably, the method comprises sealing a film sheet to a plurality of trays. Suitably, the method comprises sealing a film sheet to trays, preferably to groups of trays, in repetitive cycles.

The method may comprise an initial set up step when a new film supply is used. The set up step may comprise an operator drawing film such that it extends through the sealing means and then operating the packaging apparatus to position a tray under the sealing means with film laid over the tray positioned at the sealing means. The film may then be sealed to the tray such that film at the film supply means is connected to the tray by the film sheet. After this set up step film at the film supply means may remain connected by the film sheet to at least one tray so a further set up step will only be required if the method is stopped.

The set up step may comprise an operator drawing film such that it extends through the sealing means and then operating the packaging apparatus to position a group of trays under the sealing means with film laid over the

trays. The film may then be sealed to the trays such that film extends back from the trailing tray of the group to the film supply means. Suitably, the trailing tray may then be grouped with a trailing group of trays such that it becomes the lead tray of that group.

Suitably, the method comprises simultaneously sealing a film sheet to a group of trays. Suitably, the method comprises the additional step of cutting the film between trays. Suitably, the method comprises leaving film connected to the most upstream of the sealed trays such that the film extends back to the film supply means. Accordingly, each time the method is repeated film may be left attached to a tray such that subsequent advancement of the tray can cause more film to be drawn from the film supply means .

The method may be repeated until no film is left and/or until the desired number of trays have been sealed.

The method may comprise an end sequence once the final trays to be sealed have passed to the sealing means.

Suitably, the trays in the sealing station are sealed and then advanced such that all trays are removed from the sealing station and the film extending from the film supply means is no longer connected to any of the trays.

The end sequence may vary depending on how many trays are in the last group to enter the sealing station but a suitable sequence for any situation may comprise a three cycle sequence as follows: (i) the advancing means moves to its advanced position bringing a last group of trays

into sealing station and then disengages them after which the sealing means performs a sealing and cutting operation; (ii) the advancing means returns to reengage the trays and moves to its advanced position carrying some (or all) trays from the sealing station and then disengages the trays after which the sealing means performs a sealing and cutting operation; (iii) the advancing means returns to reengage the remaining tray (if one remains) and moves to its advanced position carrying the tray (if present) from the sealing station and then disengages the tray (if present) but in this cycle the sealing means does not perform a sealing and cutting operation .

Suitably, the method comprises sealing the film to a tray and cutting the film at a sealing station.

Suitably, the method comprises feeding a tray to the tray advancing means with a conveyor. Suitably, the method comprises taking a tray from the tray advancing means with a conveyor .

Suitably, the method comprises a method of producing a packaged product and comprises locating an object or material in a tray and then applying film to the tray and sealing film to the tray to form a sealed container.

Suitably, the method is performed with a packaging apparatus according to the first aspect.

The method may comprise any feature as described in relation to the first aspect.

According to a fifth aspect of the present invention there is provided a kit of parts for a packaging apparatus according to the first aspect, said kit comprising advancing members for removable attachment to a packaging apparatus so as to serve as advancing means of that apparatus .

Suitably, the kit further comprises press sections for removable attachment to a packaging apparatus so as to serve as sealing means of that apparatus.

The kit of parts may comprise any feature as described in relation to the first aspect.

According to a sixth aspect of the present invention there is provided a packaging apparatus arranged, in use, to draw film having a thickness of 20 micron or less from a film supply and to seal said film to trays.

Suitably, the apparatus is arranged to draw film having a thickness of 15 micron or less, for example 14 micron, from a film supply.

The apparatus may comprise any feature as described in relation to the first aspect.

BRIEF DESCRIPTION OF THE DRAWINGS

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 drawings in which:

Figure 1 shows a side view of a packaging apparatus of an embodiment of the present invention;

Figure 2 shows an opposed side view of a film supply means of the packaging apparatus of Figure 1 ;

Figure 3 shows a plan view of the film supply means of Figure 2 ;

Figure 4 shows a plan view of the tray advancing means of the packaging apparatus of Figure 1 ;

Figures 5A-5J show steps of the operation of the tray advancing means of the packaging apparatus of Figure 1;

Figure 6 is a perspective view of the film supply means;

Figure 7 is a side view of the sealing means;

Figure 8 is a plan view of a moveable (lower) press section of the sealing means; and

Figure 9 is an underside view of a fixed (upper) press section of the sealing means.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Figure 1 shows a packaging apparatus 1 of a preferred embodiment of the present invention.

The packaging apparatus 1 comprises a support bench 2, and support frame 3, a film supply means 4, a tray advancing means 5, a sealing means 6 provided at a sealing station

6A, a first endless conveyor 7 and a second endless conveyor 8. The components of the packaging apparatus 1 are arranged to work cooperatively to seal film to a tray 100.

The film supply means 4 comprises a film source having a supply of film from which film can be drawn and fed to the sealing means 6 at the sealing station 6A. To draw film from the film source the film supply means 4 further comprises a film feeder 4A which is discussed in more detail later.

The tray advancing means 5 is arranged to advance trays from the first endless conveyor 7 to the sealing station 6A, and then from the sealing station 6A and onto the second endless conveyor 8. At the sealing station 6A film is sealed to trays and cut.

The apparatus is arranged to transport trays into and out of the sealing station 6A in a repetitive process. The sealing station 6A is arranged to seal the film to trays and to cut the film between trays but to leave the upstream film attached to the trailing edge of a trailing tray. The film on the film supply means is thus connected to the trailing tray by the film extending there between.

The tray advancing means then advances the trailing tray such that film is drawn from the film supply means.

In the illustrated method of operation a plurality of trays are sealed each time the process is repeated. Thus, the tray advancing means advances several trays at a time. With this arrangement the tray which was the trailing tray in a first cycle of the method becomes the lead tray in

the subsequent cycle. The film is then cut behind the trailing edge of that tray once it becomes the new lead tray but after the film has been sealed to a new trailing tray and so the process may be repeated.

The first time the apparatus is operated with a new film source it is necessary to set up the machine by sealing the film to a tray which can then be moved to draw film from the film supply means. Subsequent to that however the film may continue to be drawn into the sealing station by the repetitive process outlined above until the film source runs out. In the example illustrated by Figures 5A-J film is sealed to a group of trays in the setup step and it is the trailing tray of that group to which film is sealed which is then moved to draw film from the film supply means. In an alternative embodiment, not illustrated, the set up step may comprise sealing film to just one tray rather than to a group of trays.

The construction of the apparatus will now be described in greater detail. The sealing station 6A comprises a moveable section 61 (lower press section) and a fixed section 60 (upper press section) . The moveable section 61 is moveable to vary the distance between a top surface 611 of the moveable section and a bottom surface 601 of the fixed section 60. In a retracted position, the moveable section 61 is arranged to be spaced apart from the fixed section 60. In an engaged position, the moveable section 61 is arranged to lie closer to the fixed section 60 such that the bottom surface 601 can engage with the film which is to be sealed to trays.

The top surface 611 of the moveable section 61 comprises a series of tray locaters 612 to assist alignment of the trays with the sealing means. The locaters 612 each bound an aperture formed in the moveable section 61 which is arranged to receive the base of a tray as the moveable section is raised so that each locater 612 engages the underside of a tray rim. As best shown by Figure 8 the apertures receive a supporting surface 5A of the advancing means when the moveable section 61 is in its lowered (retracted) position such that trays can be slid through the sealing station by the advancing arms 50, 51.

The sealing station 6A comprises sealing means 6 comprising heating apparatus 64, and a cutting apparatus 65 to seal film to a tray and cut the film to produce separate sealed containers. The heating apparatus 64 and cutting apparatus 65 both form part of the fixed section 60.

A press mechanism is provided to move the moveable section 61 between the retracted and engaged positions. In the engaged position the moveable (lower press) section 61 and fixed (upper press) section 60 cooperate to apply a predetermined pressure to the film and the top surface of the trays. The press fixed section 60 comprises a sprung plate 602 and individual presses (press parts) 603 moveable relative to the plate 602 and shaped to correspond with the tops of the trays so as to apply an individual amount of pressure to each of the trays. The individual presses operate together with the fixed and moveable sections 60, 61 but the individual presses are independently sprung to impart individual pressure on each tray .

The heating apparatus 64 is provided to heat the film to form a seal between the film and a top surface of the trays. The heating apparatus 64 comprises heating members to independently heat the film applied to each tray. The heating members are shaped to correspond to the seal flange of the tray, so that only film in contact with the seal flange is heated during the sealing operation. In the illustrated embodiment the seal flange comprises the tray edge but in alternative embodiments trays may have multiple cavities and the seal flange may further comprise an upper edge of a wall interposing cavities. The individual press 603A at the lead of the sealing means is unheated in the illustrated embodiment. Thus, in use, that individual press is arranged to engage a tray which has already been sealed in an earlier cycle of operation.

The type of seal formed between the film and the trays is determined by the type of film used, the pressure, the temperature of the heating apparatus, and the time that the press and heating apparatus are in contact with the film and the tray. Types of seal include a weld seal, a cold peel seal and a cold weld/hot peel seal.

The cutting apparatus 65 is provided to cut the film between the trays. The cutting apparatus 65 comprises cutting members 651 to cut the film at edges of the trays that touch or are adjacent other tray edges. For example, in the illustrated embodiment the packaging apparatus 1 is configured to process four trays at a time so the cutting apparatus 65 comprises three cutting members 651 to cut the film between the edges of the trays.

Film is supplied to the sealing means 6 at the sealing station 6A from the film supply means 4. Figures 1, 2 and 3 show the film supply means 4 which comprises a feeder 4A comprising a first body member 40, a second body member 41, feeder arms 440, 441, and a plurality of feeder guides 45, as well as a film reel 42, a pickup roller 43, a stopper 46 and a film guider 47.

The reel 42 comprises a roll of film 421 supported on a spindle 422. The film 421 is dimensioned to have a width corresponding to the width of the trays to be sealed. The use of film of a width corresponding to that of the trays may substantially reduce the amount of film required by the packaging apparatus 1 and so may decrease the amount of film wasted in comparison with prior art packaging apparatus .

The process of taking film 421 from the reel 42 involves drawing film 421 from the reel 42 so as to create a store of film on the feeder guides 45. Movement of a tray to which the film is sealed can then draw film from the temporary store into the sealing station 6A. Temporarily storing film in this manner may minimise the risk of film snapping or snagging which might otherwise occur if film was pulled directly from the reel 42.

Film is drawn onto the feeder guides 45 by movement of first and second feeder arms 440, 441. The feeder arms move together and are pivotally connected to the first and second body members 40, 41 at a pivot 442. The arms 440, 441 are moveable between open and closed positions. The feeder 4A is biased towards the open position by gravity and comprises a main counterbalance 443 and a fine

adjustment counterbalance 443A so as to control the level of bias. The bias of the feeder arms 440, 441 towards an open position allows film to be drawn onto the feeder guides 45. The counterbalances 443, 443A prevent the biasing means exerting too much force on the film and so may control the tension in the film.

The feeder guides 45 are arranged on the body members 40, 41 and the feeder arms 440, 441 and extend between the first and second body members 40, 41 and between first arm 440 and second arm 441. The feeder guides 45 are positioned alternately on the body members 40, 41 and arms 441, 442 to form a zig-zag pattern.

In use, the feeder arms 440, 441 pivot from a closed position to an open position. A sheet of film lying between the two sets of feeder guides 45 is thus pulled around the feeder guides 45 and drawn from the reel 42. This forms a zig-zag of film between the guides which provides a compact temporary store of film. In an alternative embodiment (not shown) the feeder guides 45 are further provided with rollers to improve the travel of film around them.

The feeder guides 45, body member 40, 41 and the feeder arms 440, 441 work cooperatively to advance film 421 from the reel 42 and communicate the film 421 to the sealing means 6. To aid the advancement of film from the reel 42, a pickup roller 43 is provided. The pickup roller 43 extends between the first and second body members 40, 41 and is arranged adjacent the reel 42. The pickup roller 43 engages with a nip roller 433 which together provide the drive required to advance the film from reel 42. The

pickup roller 43 comprises a pickup roller motor 431 attached to the first body member 40. The pickup roller motor 431 is configured to rotate the pickup roller 43 and is turned on and off using a switch 432. The switch is controlled by the movement of the feeder arms 440, 441. For example, when the feeder arm reaches a position in which it has drawn a predetermined amount of film from the reel the pickup roller motor 431 is switched off.

To ensure that film is not drawn back onto the feeder guides 45 from the sealing means 6 a stopper 46 is provided. The stopper 46 is arranged to be opened and closed to allow film 421 to be selectively drawn from the reel 42 into the temporary store or drawn from the temporary store to the sealing means 6. The stopper 46 comprises a stopper guide 461 and a stopper plate 462 extending parallel to the feeder guides 45 to provide an aperture through which the film can pass. The stopper plate 462 is moveable relative to the stopper guide 461 to open and close said aperture. In use, the stopper is switched to a closed position when the advancing means have advanced and kept in the closed position whilst the trays are sealed.

In use, when film is desired to be drawn from the feeder 4A the stopper 46 is open and so the pulling force causes the feeder guides 45 on the arms to be pulled towards those on the body moving the arm to a closed position. Once sufficient film is drawn from the feeder the stopper is closed to prevent film and trays attached thereto from being pulled back from the sealing means 6 when the advancing means 5 disengages the trays. The arm is then moved back to its open position by the bias exerted

thereon which causes film to be drawn onto the feeder guides 45 from the reel 42. Subsequently the stopper 46 is opened to allow film to be drawn to the sealing means 6 and so on.

Film is guided from the stopper 46 into the sealing means using a film guider 47. The film guider 47 is provided to align the film with the tops of the trays. The film guider 47 is a roller extending in a direction that is perpendicular to the first conveyor 7 direction of travel and is arranged adjacent to an entry into the sealing station 6A. The film guider 47 is used to ensure that the film is flush with tops of the trays so that the seal is correctly formed between the film and the trays. In an alternative embodiment (not shown) the film guider 47 is further provided with a roller to improve the travel of film around it.

Trays and film are advanced to the sealing means 6 at the sealing station 6A by the operation of the tray advancing means 5. Figures 1, 4 and 5 show the tray advancing means 5 having advancing members comprising first and second advancing arms 50, 51 to advance trays into and out of the sealing station 6A. The tray advancing means 5 also comprises first and second connecting plates 52 to connect each one of the advancing arms 50, 51 to an arm driving mechanism 53.

The advancing means 5 further includes a tray support surface 5A located between the conveyors 7 and 8 and which is arranged to support trays as they are moved by the advancing arms 50, 51. The tray support surface 5A

comprises islands fitting between apertures in the moveable part 61 of the sealing station 6A.

The trays are moved into and out of the sealing station 6A in groups by the first and second advancing arms 50, 51. The advancing arms 50, 51 are moved by the arm driving mechanism 53, which comprises a drive belt 541, track 54, track connectors 55, arm guiders 56, and a motor 57.

The motor 57 via the drive belt 541 moves the advancing arms 50, 51 backwards and forwards along the track 54 to advance the trays into and out of the sealing station 6A. The motion of the first arm is mirrored by the second arm. The motion of the arms is parallel to the support bench 2 and displacement between the arms and the support bench 2 is kept substantially constant throughout the arms movement. The track 54 is provided to guide the motion of each one of the arms 50, 51 in an elliptical, a rectangular, or any suitably shaped motion, to advance the trays.

Figure 4 shows the tray advancing means 5 having a first advancing arm 50 which is mirrored by the second advancing arm 51. Each one of the advancing arms 50, 51 comprises a plurality of fingers 501, 511 to engage with and move trays into and out of the sealing means 6.

The plurality of fingers 501, 511 extend from a stem 502, 512 perpendicularly with respect to the connection plate 52. In use, the fingers are selectively engaged with the trays to advance them into the sealing station 6A. To engage the trays, the arms are located relative to one another such that the distance between the ends of the

fingers on the first and second arms 50, 51 is less than the width of the trays to be advanced. To disengage the fingers from the trays, the arms are located so that the distance between the ends of the fingers is greater than the width of the trays .

The fingers 501, 511 are positioned adjacent each other to form bays 58, 59 between the fingers. When the arms are engaged with the trays, the trays fit into the bays 58, 59 and can be moved as the arms 50, 51 move. The first and second advancing arms 50, 51 are arranged to provide an equal number of bays 58 either side of the connection plate 52.

Adjacent to the connection plate 52, at a central point on the stem 502, 512, there is a greater spacing between fingers such that an elongated bay 59 is provided. The elongated bay 59 helps the arms 50, 51 to be repositioned and reengaged with the trays such that the trailing tray of one cycle becomes the lead tray of the next cycle. The elongated bay 59 may allow movement of a tray backwards relative to other trays moved by the advancing means. This feature may allow the trays to be positioned such that they are correctly aligned at the sealing means.

In one embodiment (not shown) tray guides are provided to receive the rim of the lead tray in order to minimise the risk of the lead tray being pulled from the elongated bay as it is moved by the arms. These tray guides extend from each one of a first and a second trailing finger 593, 594 towards a first and a second leading finger 591, 592, respectively .

Each one of the arms comprises a short finger 503, 513 at its trailing end. Each one of the short fingers 503, 513 is arranged as described for the other fingers but has a reduced length. Each one of the short fingers has a section that tapers towards an end of the arm 50, 51. The tapered section reduces the risk of a finger piercing a tray as they are engaged with the trays .

The operation of the packaging apparatus will now be described in more detail with reference to the movement of the tray advancing means 5 as shown by Figure 5.

When the apparatus is first operated with a new supply of film it is necessary to perform a set up stage. The arms are located so as to be disengaged from the trays located on the first endless conveyor 7. Film is drawn from the film supply means 4 by an operator and is positioned through the sealing station 6A extending onto the second endless conveyor 8. Trays 98, 99 and 100 are positioned on the first endless conveyor 7, as shown in Figure 5A. The arms are brought towards one another as shown in Figure 5B such that a first group of trays 98, 99, 100 which are on the first endless conveyor 7 are arranged within each one of the bays 58 lying upstream of the elongated bay 59. The advancing arms 50, 51 are then moved from their position in Figure 5B to an advanced position as shown in Figure 5C.

The advancing arms move to disengage the trays as shown in Figure 5D and then move to the position shown in Figure 5E . The film is then aligned by the operator over the trays 98, 99, 100. The film is then sealed to the trays 98, 99, 100, as shown in Figure 5E, such that the film

extends from the tray 100 back to the film supply means 4. The tray 100 is thus set up as the first tray for drawing film from the film supply means 4. The tray 100 is subsequently grouped with trailing trays such that it is set up as the lead tray for a cycle of operation as described below.

The conveyor 7 positions further trays behind the lead tray 100 while the arms remain in the position of Figure 5E as shown by Figure 5F . The apparatus is then ready to begin a first stage of a cyclical operation.

During a first stage of operation, the arms are brought towards one another to the position shown by Figure 5G (first position) The tray 100 is positioned within the elongated bay 59 such that it is the lead tray of a group of trays 100, 101, 102, 103. The trailing trays 101, 102, 103 which are on conveyor 7 are each arranged within one of the bays 58 lying upstream of the elongated bay 59.

Trays 98 and 99 are positioned within bays 58 downstream of lead tray 100 and so tray 100 is not at the lead of all the trays engaged by the advancing means. However, it is convenient to consider it as the lead tray in relation to the group of unsealed trays located in bays 58 upstream of it.

As shown by Figure 5H, in the first stage the lead tray 100 is adjacent the leading fingers 591, 592 forming the elongated bay 59 and not the trailing fingers 593, 594. This arrangement may allow the arms to move the lead tray 100 in a manner which results in reduced strain being applied to the film than would otherwise be the case.

Also, arranging the lead tray in this position allows it to be secured by the tray guides (not shown) of the advancing arms as they advance during the second stage of operation .

In the second stage of operation, the advancing arms 50, 51 are moved from their first position of Figure 5G to a second advanced position as shown by Figure 5H. In doing this they move the trays 100, 101, 102, 103 and the lead tray 100 is repositioned to the trailing end of the elongate bay 59. Trays 98, 99 are moved to the second endless conveyor 8, such that they can be taken for further processing.

In the first position the arms are arranged so that each of the connection plates 52 is adjacent to an edge of the first endless conveyor 7. In the second position the arms are arranged so that each of the connection plates 52 is arranged to be adjacent to the edge of the second endless conveyor 8.

During the set up and first and second stages, the stopper 46 is opened to allow film to be drawn from the film supply means 4 to the sealing means 6.

During the second stage the lead tray 100 is connected to the film extending from the film supply means 4. In other words the film is continuous between the reel and the lead tray 100 so film is caused to be drawn from the film supply means 4 into the sealing station 6A as the lead tray 100 is moved by the advancing arms 50, 51 moving from the first to the second positions.

The withdrawal of film from the feeder 4A of the film supply means 4 during the second phase causes the feeder arms 440, 441 to move to their closed position.

Also during the second phase, the next batch of unsealed trays 104, 105, 106 are moved by the first endless conveyor 7 towards the sealing means 6.

In a third stage of operation, the sealing station 6A seals the film applied to the trays 101, 102, 103, and then cuts the film between the trays 100, 101, 102, 103. This disconnects the first lead tray 100 from the film extending from the film supply means. However, as no cut is made behind the trailing tray 103 that tray is left connected to the film extending from the film supply means. In the subsequent stage of operation that trailing tray 103 becomes the new lead tray and the method may be continuously repeated in this manner.

During the third stage, as the film is being sealed and cut at the sealing station 6A, the advancing arms 50, 51 are moved from their second position to a third and then fourth position (Figures 51 and 5J) . Figure 51 shows the third position in which the arms 50, 51 disengage the trays while each of the connection plates 52 is adjacent to the edge of the second endless conveyor 8 as was the case for the second position of the arms. Figure 5J shows the fourth position in which the advancing arms 50, 51 are spaced apart so as to be disengaged from the trays while each one of the connection plates 52 is adjacent to an edge of the first endless conveyor 7 as was the case for the first position of the arms 50, 51. This fourth

position is also the same as the position of the arms shown in Figure 5F .

Also during the third stage, the stopper 46 is closed and the motor 431 is turned on, to enable a predetermined amount of film to be drawn onto the feeder 4A.

In the fourth stage of operation (not shown) , which corresponds generally to the first, the advancing arms 50, 51 are moved to their first position and commence a second cycle. This time as film is attached to the trailing edge of a tray there is no need to first set the apparatus as there was before the first cycle.

As the conveyor 7 has brought three further trays 104, 105, 106 up behind the tray 103 the arms engage these such that tray 103 is now located in the elongate bay 59 and becomes the new lead tray.

In the fifth stage of operation (not shown) , which corresponds generally to the second, the advancing arms 50, 51 are moved to their second position. As well as advancing tray 103 through the sealing station and trays 104, 105 and 106 into the sealing station this moves the trays 100, 101, 102 in front of the new lead tray 103 onto the second endless conveyor 8 such that they can be taken for further processing.

The sixth stage of operation (not shown) corresponds generally to the third and the advancing arms 50, 51 are moved to third and then fourth positions. Meanwhile the film is sealed to the trays and cut such that the trailing edge of tray 106 remains connected to the film extending

from the film supply. This completes the second cycle and following this the method of stages four five and six can be repeated in subsequent cycles.

As the film only needs to be set up during the set up stage performed before the repetitive cycles begin the only film wasted by the packaging process may be the film used to set up the first trays 98, 99, 100 to be sealed.

A small quantity of film may also be wasted at the end of the process.

To end the process when film is left on the supply roller after the last trays to be sealed have entered the sealing station 6A an operator can instruct the apparatus to perform an end sequence step.

In a preferred embodiment the end sequence step comprises the following operations: (i) the advancing means 5 moves to its advanced position bringing a last group of trays into the sealing station and then disengages them after which the sealing means 6 performs a sealing and cutting operation; (ii) the advancing means 5 returns to reengage the trays and moves to its advanced position carrying some (or all) trays from the sealing station and then disengages the trays after which the sealing means 6 performs a sealing and cutting operation; (iii) the advancing means 5 returns to reengage the remaining tray (if one remains) and moves to its advanced position carrying the tray (if present) from the sealing station and then disengages the tray (if present) but in this cycle the sealing means 6 does not perform a sealing and cutting operation.

The active components of the packaging apparatus 1 are arranged and supported by a support bench 2 and a support frame 3. The support bench 2 comprises a planar support surface 20 upon which the support frame 3 and other components are arranged. The support bench 2 also comprises adjustable legs 21 which allow the support bench

2 to be levelled during installation. This may ensure that the components of the packaging apparatus 1 are correctly aligned for the purpose of sealing film.

The support frame 3 extends perpendicularly upwards from the support surface 20. The support frame 3 comprises first and second conveyor supports 30, 31, a plurality of support legs 36, a plurality of cross beams 37, a plurality of support beams 38 and plurality of support plates 39. The support frame 3 is arranged on the support surface 20 and is configured to support the active components of the packaging apparatus 1.

To ensure the trays are correctly guided to and from the sealing station conveyor guides (only second conveyor guides 81 shown) are provided to keep the trays central on the conveyor .

Preferred embodiments of the packaging apparatus 1 of the present invention may provide many benefits over known packaging apparatus. A key benefit may be the reduction of wasted film. The skilled person will also appreciate that other benefits in terms of efficiency and throughput may also be generated.

Although a few preferred embodiments have been shown and described, it will be appreciated by those skilled in the art that various changes and modifications might be made without departing from the scope of the invention, as defined in the appended claims.

Attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

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.