GB2218079A

GB2218079A - Packaging

Info

Publication number: GB2218079A
Application number: GB8909718A
Authority: GB
Inventors: Peter Frank Kershaw; Edward Roger Costello
Original assignee: MCLENNON J L Ltd
Current assignee: MCLENNON J L Ltd
Priority date: 1988-04-27
Filing date: 1989-04-27
Publication date: 1989-11-08
Anticipated expiration: 2009-04-27
Also published as: GB8909718D0; GB2218079B; GB8809938D0

Abstract

A method of and apparatus for packaging food, beverage or other commodity in a container having an interior volume comprises, providing an insert I, having a passage therein to communicate the interior volume of the insert with the exterior thereof and disposed within the container, with a predetermined atmosphere therein, comprising the steps of introducing the insert into the container with the insert containing an atmosphere of an initial composition, changing the atmosphere in the container and thereby changing the atmosphere in the insert. <IMAGE>

Description

Title: "Method of and an apparatus for packaging" Deseription of Invention This invention relates to a method of, and an apparatus for packaging food, beverages or other commodities in a container.

According to one aspect of the present invention we provide a method of packaging food, beverage or other commodity in a container having an interior volume comprising, providing a insert, having a passage therein to communicate the interior volume of the insert with the exterior thereof and disposed within the container, with a predetermined atmosphere therein, comprising the steps of introducing the insert into the container with the insert containing an atmosphere of an initial composition, changing the atmosphere in the container and thereby changing the atmosphere in the insert.

The atmosphere may be changed by subjecting the interior volume of the container to a sequence of pressure changes to change the atmosphere therein.

The sequence of pressure changes may comprise evacuating an initial atmospheric gas from the interior volume of the container and then introducing a further gas of a different composition into the interior volume.

The exterior of the container may be subjected to a similar sequence of pressure changes.

The container may be disposed within an enclosure with the interior volume of the container in communication with the enclosure and the enclosure may be subjected to said sequence of pressure changes.

The initial atmospheric gas may be evacuated by subjecting the interior volume to a pressure below ambient atmospheric pressure and preferably a vacuum of at least 10" of mercury and preferably at least 20" of mercury and more preferably in the range 20" to 30" of mercury.

The further gas of a different composition may be introduced into the interior to provide a pressure above ambient atmospheric pressure.

The sequence may comprise performing in at least one further evacuation of the interior volume, the or each further evacuation being followed by introduction of a further gas of a different composition from the initial atmospheric gas.

Where further gas is introduced into the interior volume more than once the further gas may be of the same composition at each introduction.

The pressure above atmospheric pressure at which the further gas is introduced at the or each introduction may be at least 20 psi or may be up to 30 psi or may be lower than 20 psi or higher than 30 psi if desired.

After introducing the further gas for the or the last time the interior volume may be connected to ambient atmosphere.

After said sequence of pressure changes the interior volume of the container may be connected to a port through which a commodity to be stored may be introduced into the interior volume.

The exterior of the container may at this stage be subject to a different pressure, such as ambient atmospheric pressure or, preferably a pressure above ambient pressure, than is the interior volume. Where the container is disposed within the enclosure the enclosure may be connected to ambient atmosphere and the interior of the container may be isolated from the interior of the enclosure and in sealing engagement with said port.

A gas of desired composition and pressure may be introduced ibto the container, prior to introduction of said commodity into the interior volume through said port, therein to provide a counter pressure in the container to facilitate maintenance of container shape and hence sealing engagement with the port.

The counter pressure may be released in a predetermined manner after filling has been completed.

Alternatively a commodity to be stored may be introduced into the interior volume before subjecting the interior volume to the sequence of pressure changes to change the atmosphere therein.

In either case after performance of the sequence of pressure changes the container may be transferred to a sealing station whereat the interior volume is sealed from communication with the exterior of the container.

The initial atmosphere may comprise ambient atmosphere and the further gas may comprise nitrogen which is preferably as pure as commercially available. If desired any other desired gas or mixture of gas ma" be provided.

The insert may be placed in a container which has a neck, wherein the insert is of greater longitudinally extent than the cross-section of the neck, by holding the insert in a first orientation whilst causing relative movement between the insert and the container to introduce the insert into the container through the neck and subsequently moving the insert into a second, different, orientation relative to the first orientation to place the insert in a desired orientation in the container.

In the second orientation the insert may engage the wall of the container to retain the insert in said desired orientation in the container.

The neck may be circular in cross-section and the insert may be elongate having a greater longitudinal extent than transverse extent and in the first orientation the insert may be tilted about an tranversely extending axis so as to present a projected longitudinally extent in the direction of introduction which is less than the cross-section of the neck.

According to another aspect of the invention we provide an apparatus for packaging food, beverage or other commodity in a container having an interior volume comprising, providing an insert, having a passage therein to communcate the interior volume of the insert with the exterior thereof and disposed within the container, with a predetermined atmosphere therein, comprising means for introducing the insert into the container with the insert containing an atmosphere of an initial composition and means for changing the atmosphere in the container and thereby changing the atmosphere in the insert.

The means for changing the atmosphere in the container comprise means for subjecting the interior volume of the container to a sequence of pressure changes to change the atmosphere therein.

The apparatus may be provided with means to evacuate an initial atmospheric gas from the internai volume and means to introduce a further gas of a different composition into the interior volume.

Means may be provided to subject the exterior of the container to a similar sequence of pressure changes.

Said means may comprise an enclosure within which the- container may be disposed, with the interior volume of the container in communication with the enclosure and means to subject the enclosure to said sequence of pressure changes.

Said means to evacuate initial atmospheric gas from the interior volume may comprise vacuum generating means which may be capable of generating a vacuum of at least 10" of mercury and preferably at least 20" of mercury and more preferably in the range of 20-30" of mercury.

Said means to introduce further gas of a different composition may be capable of introducing the gas to provide a pressure therein above ambient atmospheric pressure.

The apparatus may comprise a port connectable in communication with the interior of the container through which a commodity to be stored may be introduced into the interior volume.

The apparatus may comprise means to permit of a different pressure to be applied to the exterior of the container than is applied to the interior volume during said introduction of the commodity.

Where the apparatus comprises an enclosure in which the container may be disposed means may be provided to connect the enclosure to ambient atmosphere and to isolate the interior of the container from the interior of the enclosure and connect the interior volume in sealing engagement with to said port.

Means may be provided to introduce a gas of desired composition and pressure into the interior volume, for example through said port, prior to introducing said commodity to provide a counter pressure within the interior volume.

Alternatively means may be provided to introduce a commodity to be stored into the interior volume before operating said means to subject the interior volume to said sequence of pressure changes to change the atmosphere therein.

In either case after operating said means to perform said sequence of pressure changes transfer means may be provided to transfer the container to a sealing station whereat the interior volume is sealed from communication with the exterior of the container.

The apparatus may comprise a container support, which defines a base part of said enclosure, movable into engagement with a chamber member which defines the remainder of said enclosure so that movement of the container support into sealing engagement with the chamber disposes the container into the enclosure.

The container support may be arrestable in a first position in which the enclosure parts are sealing engaged and in which the interior volume of the container is in communication with the interior of the enclosure so that said sequence of pressure changes may be performed.

The container support may then be moved to a further position in which the container is moved into sealing engagement with the said port to isolate the interior volume from the interior of the enclosure.

A displacing member may be disposed within the container, when the container is in position to have said commodity introduced therein, so that when the container is removed from the enclosure and the displacing member is removed from the interior thereof the level of commodity in the interior volume falls below that which it occupied whilst within the enclosure with the displacing member therein.

Means may be provided to hold the enclosure member in engagement with the container support member during the performance of said sequence of pressure changes. Said means may comprise a stop to prevent movement of the base wall of. the container, the stop projecting downwardlY from said port.

An apparatus may place an insert in the container, which has a neck, wherein the insert has a longitudinally extent which is greater than the crosssection of the neck, the apparatus comprising a holding means to hold the insert in a first orientation; means to cause :relative movement between the holder and a support Jar the container so as, in use, to introduce the insert into the container through the neck, and means to cause said holding means to move the insert into a second, different, orientation relative to the first orientation.

The holding means may be mounted for movement about an axis transverse to the direction of said relative movement.

The holding means may comprise a vacuum head to apply a vacuum to the insert to retain the insert in engagement with the head.

The holding means may be pivoted about said axis bv a mechanical linkage which extends outwardly of the container, in use, for engagement by an operating member.

The container mav be filled by means of a liquid feed head comprising a valve seat member having a plurality of feed passages formed in a monolithic portion thereof.

The feed passages may be disposed in a skirt part of the seat member which extends uninteruptedly around at least part of an arc of a circle and the feed passages being disposed around said circle.

Preferably the skirt part extends around a complete circle and is generally annular in cross-section taken normal to the centre of said circle.

The skirt part may be generally fusto-conical having a larger diameter towards the discharge end of the feed passages.

Each feed passage may have a longitudinal axis which lies in a conical surface centered on said circle.

Each feed passage may be inclined in said conical surface relative to a diametric plane thereof containing the axis of the conical surface.

The conical surface may have an included angle of appropriate 210 and the feed passages may be inclined to said diametric plan at an angle of approximately 10 The head may comprise a valve member movable relative to the seat member to control discharge of liquid through the feed passages.

An example of the invention will now be described with reference to the accompanying drawings wherein: FIGURE I is a plan view of an apparatus embodying the invention; FIGURE 2 is a cross-section, to an enlarged scale through part of a workstation of the apparatus shown in Figure I and showing a container seat; FIGURE 3 is a further cross-section similar to that of Figure 2 of a different part of the workstation and showing an enclosure member; FIGURE 4 is a cross-section on the line 4-4 of Figure 3; FIGURE 5 is a further cross-sectional view similar to that of Figure 2 of a further part of the workstation and showing a filling head; FIGURE 6 is a fragmentry section to an enlarged section through the parts shown in Figure 5; FIGURE 6a is an underneath plan view of the part shown in Figure oe;; FIGURE 6b is a side elevation of the filling head shown in FIGURES 3 to 5; FIGURE 7 a further cross-section similar to that of Figure 2 of a still further part of the workstation and showing an operating ram.

FIGURE 8 is a diagrammatic plan view of a insert workstation for use with the apparatus of Figures I to 7; FIGURE 9 is a cross-section, to an enlarged scale, showing part of the workstation of Figure 8; FIGURE 10 is a cross-section on the line 10-10 of Figure ?; and FIGURE II is a cross-section on the line Il-Il of Figure 10.

Referring now Figure 1, a work platform 10 is mounted to be driven by a suitable electric motor and drive means 11 in an anti-clockwise direction as shown in Figure I. The platform 10 is provided with a plurality of workstations 12 at equally spaced position around its circumference. In this application there are 40 workstations, only one of which is shown.

Also extending around the table 10 adjacent its circumference are three tubular manifolds l3a-l3c connected by pipes l4a-l4c respectively to each workstation 12 as hereinafter to be described. Each manifold, I 3a- I 3c is connected by a generally radially extending conduit lSa-l5c respectively to an associated rotary joint 16a-16e so that an appropriate feed to each manifold I 3a- I 3c is communicated from the appropriate static supply means hereinafter to be described.

Referring now to Figure 2, each workstation 12 comprises a container support comprising a container seat member 20 having a replacable wear pad 21 and semi-circular upstanding wall 22 which together cooperate to support and locate a container C at the workstation. The seat member 2O is, in the present example, slidably mounted on a boss 22a with a coil compression spring 23 acting therebetween. A roller 24 is rotatably mounted, by means of eccentric arrangement 25, on the seat member 20 and the surface 26 of the roller 24 is adapted to engage a guide surface 27 of a container feed means F (Figure 1) so that the wear plate 21 is correctly aligned with the feed means F as a result of downward depression of the seat member 20 by the roller 24 against the bias of the spring 23.The boss 22a is carried on a piston rod 28 of a two-stage pneumatic ram 29 fixed to the table 10. The ram 29 has bolted thereto a lug 30 from which.a pillar 31 projects upwardly and is received in a sliding bearing member 32 connected to the seat member 20 so as to prevent rotation of the seat member 20 relative to the housing of the ram 29 which is fixed to the table 10.

An enclosure base part 35 is slidably mounted on the exterior of the seat member 20 under the influence of a coil compression spring 36 which normallybiases the member 35 upwardly. Upward movement is limited by engagement with a shoulder provided at 37.

Referring now to Figure 3 mounted on the table 10 above the container seat member 20 is a filling head 40 having a Plurality of liquid filling nozzles 41. The filling head 40 carries a chamber member 42 the lower end of which is adapted for sealing engagement with a sealing washer 38 provided on the base part 35 described hereinbefore. To facilitate this the lower end surface 43 of the chamber member 42 is angled to provide a sharp edge 44 for sealing engagement with the washer 38.

The chamber member 42, as best shown in Figure 4 is provided with four poppet valves V1, V2, at an upper position and N2, Ex, at a lower position.

The valve VI is connected to manifold 13a, the valve V2 to manifold 13b and the valve N2 to manifold 31 c whilst valve Ex is connected to atmosphere via a filter. All the valves operated in a similar manner to the valve Vl and V2 shown in Figure 4. The valve VI comprises a valve member 46 urged by a coil compression spring 47 against a seat 48 to prevent communication between a passage 49a and a passage 49b.An operating rod 50 of a smaller diameter than the passage 49a extends longitudinally of the passage 49a to a tappet member 51 provided with sealing rings 51a and engaged by a rocker arm 52 pivoted to the member 42 by a pivot rod 53 and carrying a roller 54 for engagement with a cam which encircles the work table 10 and of an appropriate configuration to open and close the valve Vl at the desired angular position as hereinafter to be described.

The valve V2 and the other valves operate in an exactly analogous manner and will not be described further.

The passage 49a of the valve Vl and the corresponding passages of the other valves intersect a chamber 55 which communicates via apertures 56 with the interior of the chamber member 42.

Referring now to Figure 5, the filling head 40 comprises a bonnet 60 which is carried by the table and has connected thereto, by cap screws ól, a valve seat 62 which has a monolithic frustoconical skirt part 63 in which are provided a plurality, in the present example 16, of feed passages 64 which provide the nozzles 41. The passages 64 lie in a conical surface having a semi-angle of 210 to the vertical as shown at A in Figure 6 and are inclined a in the conical surface at an angle of 15 to a line formed by the intersection of the conical surface with an axial diametric plane thereof, as shown at B in Figure 6. If desired a different number of passages and different angles to those described above may be provided.Mounted within the bonnet 60 is a valve member 65 having a resilient seal 66 thereon which is movable thereby into and out of sealing engagement with a valve seat surface 67 and thus to control flow of liquid through the passages 64. The valve member 65 is carried on a tube 68 which carries a bearing member 6 slidably mounted in a tubular extension 70 of the valve bonnet.60. Adjacent its lower end the tube 68 is fixed to the valve member 65 and has an extension part 71 which is slidably received in a bore 72 in the valve seat member 62. A coil compression spring 73 acts between the bearing member 69 and a shoulder 74 provided within the tubular extension 70 to provide a lifting bias to the tube 68 and hence to the valve member 65.

At its upper end the tube 68 carries a valve 75 which comprises a valve member 76 having a cylindrical skirt 77 which surrounds the tube 68 and guides the valve member 76 for sliding movement thereon. A coil compression spring 78 acts between a shoulder 79 at the lower end of the skirt 77 and a circlip 80 provided on the tube 68. On the opposite side of the valve member 76 is an operating stem 8 1 having a head 82 and a fork member F receives the stem 81 between the times thereof and can engage the valve member member 76 so as to urge the valve 76 against the end of the tube 68 to close the valve.The fork member can be operated by engagement with a cam surrounding the table at an appropriate position within the cycle of rotation of the station to permit the spring 78 lift the valve member 76 out of sealing engagement with the tube ó8.

The tube 68 and extension 70 of the bonnet are provided within a reservoir 5 of liquid to be fed into the container C with the liquid level being as indicated by the line L-L so that the upper end of the tube 68 is above the liquid level. The reservoir is closed to atmosphere and in the present example is filled with commercially pure nitrogen at a pressure of about 27 psi. Slots 70a are provided in the extension 70 to permit of liquid to pass therethrough.

A passage 82 extends from each passage 64 to an annular recess 84 which is connected by a passage 85 to an annular recess 84a which is connected by a passage 85a to a valve 86 to which nitrogen is fed via an inlet 86a and which is operated by engagement with a cam at an appropriate position in the cycle of rotation.

Mounted within the part 63 of the valve seat member is a check valve housing 57 which carries a seal member 88 with which a ball closure- member 89 is moved into engagement as a result of the ball 89 floating when the liquid level in the container rises so that the ball floats therein.

Referring now to Figure 7, the pneumatic ram 29 comprises a cylinder 90 having a primary piston 91 in sliding and sealing engagement therewith.

The primary piston 91 is connected to the piston rod 18 and mounted within the cylinder 90 for sliding and sealing engagement therewith is a secondary piston 92. An air entry port, not shown, is provided to permit air to act on the underside of the piston 9 1 to move the piston 91 and hence the rod 18 upwardly and a further port 93 is provided for exit of air from above the piston 9 1 during lift. Of course, the supply of air is reversed when it is desired to lower the piston 91. A further port 94 is provided to supply air-to act on the upperside of the piston 92. A valve block 95 is provided at the lower end of the cylinder 90 to a control flow of air through the above described ports by virtue of engagement of operating members 96 with a cam around the periphery of the table 10.

Containers C, which in the present example are deep drawn aluminium cans of the type conventionally used today for beer and soft drinks, are fed frorn a supply to the table 10 by the feed means F which comprises a conveyor 100 to a feed star wheel 101 using a scroll worm to appropriately pitch the containers. The star wheel 101 rotates in a clockwise direction and so feeds cans to the periphery of the table 10 in the same direction as the table is rotating. The wheel 101 is geared to the rotation of the table 10 so that a container C is delivered to a seat member 20 as each workstation passes the wheel 101.

Disposed within each container C is a hollow insert I made as an assembly of plastics mouldings and having a relatively small opening therein of the order of 0.0010-0.015 inch diameter and a volume of about 20 cc.

In use, the ram 29 is operated so that the primary piston 91 thereof is at its lowermost position whereby the associated seat member 20 is also in the lowermost position shown in Figure 2. The wheel 24 carried on the seat member 20 can engage surface 27 to ensure that the weqr pad 21 is correctly aligned with the feed path of the containers. In practice, it has been found that such an arrangement is not necessary and therefore, if desired, the wheel 24 and associated movable mounting of the seat member 20 can be omitted and the seat member 20 fixed rigidly relative to the piston rod 28.

After a can has been fed onto the seat member 2cl), the can is carried in a circular path by the rotation of the table 10. As the table rotates the operating members qó on the lower end of the ram 29 are cnus.ed by the associated cam to feed air to act on the underside of the piston 91 to lift the piston rod 18 and hence the seat member 20 and the can carried thereon until the upper end of the piston 91 engages the underside of the piston 92 where movement of the piston 91 is arrested. The position of the piston 92 is determined by the pressure of air, acting on the upperside of the piston 92, fed through the port 94 under the control of the associated valve in the valve block 95.This upward movement of the valve seat is such as to move the base member 35 into sealing engagement with the lower end 43 of the chamber 42.

As a result, the chamber member 42 and the seat member 20 cooperate to form an enclosure E within which the can is disposed. In this condition the upper end of the can is spaced downwardly a short distance e.g. 7 mm from a container seal member S provided on the feed head 40. Thus the interior IC of the container C is in communication with the interior lE of the enclosure F.

The stop member 59 engages the upper surface of the insert I to hold the container against the seat member 20 during subsequent operations now to be described. The seat member 20 and member 35 together provide a base part of the enclose U and the spring bias of the member 35 permits of sealing engagement of the enclosure Darts 42 and 20 whilst permitting further upward movement of the seat member 20.

After thus disposing the container within the enclosure E continued rotation of the table 10 causes the cam follower roller associated with the valve Vl to engage a portion of the cam which causes the valve Vl to be opened and thus connect the interior of the enclosure to a two-stage vacuum pump which evacuates the initial atmosphere within the container and enclosure i.e. ambient atmosphere at ambient pressure, and produces a vacuum of approximately 27" of mercury. If desired the vacuum may be higher or lower, for example down to 20" Hg. The system-is arranged to achieve- this vacuum in a time of n.4 seconds.Continued rotation of the table then causes the valve Vl to close and the valve N2 to open to feed commercially pure nitrogen into the interior of the enclosure E and hence into the interior of the container C to provide a pressure therein of 27 psi. If desired however the pressure may be higher or lower than this for example between 23 psi and 30 psi. The svstem is arranged so that after initiation of nitrogen feed the desired pressure is achieved in 0.2 seconds.

Continued rotation causes the valve N2 to close and the valve V2 to open to connect the interior of the enclosure to a three-stage vaccum pump to evacuate the nitrogen from the interior of the enclosure and hence from the container and produce a vacuum of approximately 27" of mercury in 0.4 seconds.

Thereafter valve V2 is closed and the valve N2 is again opened to again charge nitrogen into the enclosure and hence into the interior of the container to create the same pressure as before in 0.2 seconds. If desired, of course, nitrogen may be charged to attain a different pressure at this stage.

Thereofter the valve V2 is opened and the valve N2 is closed and the vacuum pumps again evacuate nitrogen from the interior to produce a vacuum of the same extent as the previously again in 0.4 seconds. If desired a vacuum of different extent may be created at this stage.

The valve V2 is then closed and the valve N2 again opened and the interior of the enclosure and the container charged with nitrogen again up to the same or a different pressure in 0.2 seconds.

The valve N2 is then closed and the valve Ex opened and at the same time the second stage of lift of the ram 29 is initiated by permitting air to exit through the port 94 so that the piston 91 and the piston 92 can move upwardly and move the container C into sealing engagement with the container seal S.This condition is shown in Figure 4.In addition the valve 75 is opened to permit nitrogen under pressure from the reservoir w to pass through the tube 68 and hence enter the container (z. The sequence is such that the container is brought into initial engagement with the seal S before the pressure in the enclosure E and hence within the container C, has fallen to atmospheric pressure and the valve 75 is opened to apply counter pressure within the container so that as the container is brought fully into sealing engagement with the seal S the full counter pressure is established and the exhaust valve Ex is closed and the nitrogen valve N2 is opened to apply a pressure, below the counter pressure, to the exterior of the, container.The pressure above the reservoir R is, in the present example 27 psi and hence the counter pressure within the container C is also 27 psi. The pressure externally of the container within the interior IE of the enclosure E is arranged to be somewhat less than the counter pressure, for example 22 psi. The counter pressure helps prevent the can deforming whilst it is pressed against the seal S because the cans used are relatively fragile and reauire the presence of a counter pressure to prevent the neck of the can collapsing out of sealing engagement with the seal S. The pressure on the exterior of the container avoids any significant barrel shaped deformation of the container due to the counter pressure. In addition the apparatus operates more quietly when the container is lowered out of engagement with the seal S as hereinafter to be described.

Because of the relatively high vacuum and rapid extraction of the initial atmosphere and the further atmosphere of nitrogen by the vacuum pumps through the valves VI and V2 there is a tendency for the can to be lifted out of engagement with the seat member 20 hence the provision of the stop 59.

When the counter pressure in the container interior IC equals the pressure of the liquid in the reservoir R the pressure difference acting on the valve member 60 is solely that arising from the weight of the liquid in the reservoir. This force is less than the force applied by the spring 73 and so the spring 73 lifts the valve member 60 out of sealing engagement to permit liquid to flow through the passages 64 into the container. When the liquid level in the container has risen so that the ball 89 floats, egress of nitrogen through the tube ó8 is prevented so that the pressure in the head space above the liquid increases and so creates a back pressure which prevents further flow of liquid.In practice the ball 89 may not remain in sealing engagement with the seal member 88 so that although the main flow of liquid is checked a residual amount of liquid continues to enter the container. The level to which the liquid thus rises depends upon the time interval between initial operation of the check valve and closure of the valve 75 as a result of table 10 continuing to rotate to cause the cam acting on the fork to close the valve 75 and to move the tube 68 downwardly to mechanically move the valve member 60 to close the passages 64.

Because of the volume of the skirt part 63 containing the passages 64, although the level of the liquid may rise to closely adjacent the top of the container whilst the container is in sealing engagement with the seal head, the majority of the volume is occupied by the skirt part 63 and fherefore relatively little extra liquid enters the can even though the level may rise significantly above the level of the bottom of the skirt part 63 which is the level at which the check valve is intended to operate.

Accordingly, when the container is lowered to remove the skirt part 63 the level of liquid will fall and thus relatively accurate control of liquid level is achieved.

Continued rotation of the table 10 causes the pneumatic ram to lower the can C out of engagement with the seal S. In addition, the cam acting on the valve 86 causes this to be actuated to feed nitrogen under pressure into the passages 64 to force the beer retained in the passages 64 out of the passages and into the can.

The differential pressure acting on the valve member 60 then comprises ambient atmospheric pressure acting on the underside thereof and the pressure in the reservoir R plus the weight of the liquid on the upper side thereof so that the valve member ó0 remains in sealing engagement with the valve seat when the fork member is moved upwardly during the next cycle to open the valve 75 to apply the counter-pressure.

Alternatively, if desired the valve 86 can be connected to atmosphere and, if desired, instead of being connected to the passages 64, may be connected through a separate passage 82a, shown in dotted line in Figure 2, to a space 83 within the frusto conical part 63 of the valve seat member 62.

In this case the cam acts on the valve 86 to connect the space 83 to atmosphere before the can is lowered. After such operation of the valve 86 the differential pressure acting on the valve ó0 is as described above and the valve member o'0 remains in sealing engagement with the valve seat as described above.

Continued rotation of the table 10 causes the cam acting on the members 96 of the ram 29 to cause the piston rod thereof to be moved downwardly further to lower the seat member 20 to remove the container C from within the enclosure E and then the thus filled container is removed from the seat member 20 in conventional manner and is then fed along a conveyor 102 to a sealing station where a cap is sealed onto the top of the container in a conventional seaming operation.

If desired a dose of liquid nitrogen may be introduced into the liquid in the container prior to sealing the can. As the liquid nitrogen changes to the gaseous state it drives out any ambient atmosphere which may have entered the top of the can after snifting and also provides a pressure above atmospheric pressure within the can during the closing operation thus helping to rigidify the can during this operation and maintain a pressure above ambient atmospheric pressure within the can.

The above described sequence of gas exchange where there are three introductions of nitrogen with intervening vacuum extractions ensures that the atmosphere within the insert is substantially wholly nitrogen. It has been found that with the relatively small diameter of opening a lesser number of exchanges does not ensure a substantially complete atmosphere of nitrogen within the insert.

When the container is filled with liquid, the liquid can enter the insert through the small opening and where the container is sedled under pressure, for example, as a result of introducing a dose of liquid nitrogen as described hereinbefore, the resultant pressure within the can is also, of course, exerted within the insert and the liquid in the insert can contain the gas in solution and may be saturated or supersaturated therewith.

In this example the opening is on the underside of the insert and hence only part of the insert becomes filled with liquid, the remainder being occupied by nitrogen trapped therein above the liquid. The opening can be disposed at other positions such as in the side wall or on the top of the insert.

The position of the opening governs the amount of trapped nitrogen.

Subsequently, when a user opens the can the pressure is released and this causes liquid and/or nitrogen to escape through the small opening which agitates the liquid in the main body of the container, for example, to aid nucledtion and growth of bubbles and/or to cause mixing or frothing depending upon the contents of the container. The insert may be made of any suitable material and have a volume considerably less than that of the container, for example, 10 - 20cc for a 500cc container. The opening mav be of any desired shape, but in this example is circular and of about 0.5 to I .Omm diameter, but may have a size lying in the range 0. I to 3mm diameter.

Where the opening is not circular it may have the same cross-sectional area as the above mentioned circular openings.

The size of the skirt part 63 is such that it acts as a displacing member of appropriate volume to ensure that there is a relatively large head space above the liquid in the container after the container has been moved out of filling relationship with the filling head and this head space can be used to accommodate any froth created on opening of the container- without causing the froth to spill out of the container.

If desired a separate displacing member may be Drovided carried on the end of a conventional check valve housing 57 such as that shown in dotted line at 58 in Figure 3.

Although in this example there has been described one extraction of ambient atmosphere followed by three introductions of nitrogen with two intervening vacuum extractions a different sequence may be performed depending on the internal volume of the insert and the size of the opening or openings. For example there may be a single vacuum extraction of ambient atmosphere and a single introduction of nitrogen. Alternatively there may be a greater number of gas exchanges. If desired a different gas may be introduced at different stages if, for example, it is found that a particular gas is useful at an intermediate stage, for example, to perform a cleaning or similar operation on the interior of the container in any particular application. The pressures and time as mentioned hereinbefore may be varied as desired.

In a modification, not illustrated, for example where a commodity to be packed is a dry commodity such as peanuts the container may be filled to a desired extent with the commodity prior to performing the sequence of gas exchanges. A suitable insert being disposed within the container before or after packaging the commodity. In one such modification the container is filled with the commodity at a position remote from the table 10 and the filled container is fed to the table 10 where the containers are positioned within the enclosures E as described hereinbefore and the gas exchange operation is then performed. Of course the liquid filling operation is omitted.

Then the containers are fed to a sealing station. The containers may be provided with a closure such as a screw-threaded lid which may not be fully tightened so that the gas exchange can take place then the containers may be sealed by tightening the lid. Alternatively another form of sealing means may be provided. If desired means may be provided to permit the sealing operation to be carried out within a desired protected atmosphere which may be of the same atmosphere as that provided within the container. For example instead of providing a liquid filling head in the enclosure a sealing means may be provided within the enclosure.

In a further modification, applicable where the container is sufficienly strong, the above described cycle of gas exchange or any of the modified versions of gas exchange described hereinbefore may be applied directly to the interior of the container without applying the same pressure to the exterior of the container. In one such modification, the apparatus is as described as hereinbefore with reference to the Figures except that the filling head is modified to provide at least one further conduit which is connectable to the valves V I, V2, N2, Ex described hereinbefore so that communication is established directly with the interior IC of the container C and the sequence of gas exchange performed whilst the exterior of the container is subjected to a different pressure, for example, ambient atmospheric pressure. In this case the enclosure is not necessary.

Alternatively, if desired, the exterior of the container may be subjected to a pressure which differs from that in the interior of the container but which is determined to, for example, maintain the shape of the container in a desired configuration. For example, the exterior of the container may be subjected to a pressure below atmospheric pressure of the same or similar vacuum to that created in the interior of the container to prevent inward deformation of the container on application to vaccum to the interior thereof. This vacuum may be continued to be applied when gas such as nitrogen is introduced under pressure to the interior of the container since a thin wall container of the sort typically used for beer or other drinks is capable of withstanding relatively high internal pressures.In this modification the apparatus would be as described hereinbefore but the container would be moved initially into sealing engagement with the seal S and the enclosure would be independently connected to a source of vacuum or such other pressure/vacuum it is desired to apply to the exterior of the container at any particular stage in the pressure cycle applied to the interior valve.

Further alternatively, if desired, the container may be moved directly into engagement with the seal S and the desired sequence of gas exchange with the interior valve performed through the filling head whilst the exterior of the container is subjected to the same sequence of pressure changes by appropriate passages leading from the enclosure interior and controlled by the valves described hereinbefore.The inserts may be placed within the containers C using the apparatus shown in Figures 8 to 11 to which reference is now made.

An insert placing apparatus comprises a work table 110 rotatable about a central axis Ill by a suitable drive means 112. The table 110 has a plurality, in the present example 30, of workstations each having a container seat 113, each of which is adapted to receive and support a container such as a beer or soft drinks can C of essentially cylindrical configuration fed from a source of supply by a conveyor 114 onto a feed star wheel 115 via a scroll worm 116 to space the cans appropriately for engagement by the star feed wheel 115. In the present example the table 110 is rotated clockwise and the star feed wheel anti-clockwise so that the cans are moving in the same direction as the seats 113 as they are moved into engagement therewith.

Inserts I to be introduced into each can are fed to the table 110 by a conveyor 118 and are engaged by an insertion head 12n shown in Figure 9 associated with container seat at each workstation. Each head 120 comprises a support bar 121 which carries an inner bar 122 with a tubular neck 123 of an upper support 124 therebetween. Extending upwardly within the neck 123 and inner bar 122 is a tube 125 connected at its upper end by a flexible tube 126 to a source of vacuum and connected by a flexible tube 27 at its lower end to a vacuum head 28 hereinafter to be described. The upper support 24 has connected thereto a generally cylindrical spacer block 129 at the lower end of which is carried a mounting plate 130. Bolts 131 connect the mounting plate 130, spacer block 129 and upper support 124 together.

Side plates 132 are connected by screws 133 to the mounting plate 130 and corry at their lower ends bearing members 134 having a blind bore 135 in which is rotatably received cylindrical projections 136 of a pivot block 137 which carries the vacuum head 128.

The pivot block 137 has a pair of upstanding arms 138 which carry a pivot pin 139 which is received in slots 140 formed in a first pair of arms 141 of a bell crank lever 142 mounted for rotation between the side plates 132 by means of a pivot pin 143. The other pair of arms 144 of the bell crank lever 142 have slots 145 within which is received a pivot pin 146 at the lower end of an operating rod 147. The operating rod 147 is arranged to slide in a bore 148 formed in the spacer block 129 and the upper end of the rod ;47 is adpated to be engaged by an oDerating roller 149 An end cap 150 is provided at the lower end of the spacer block 122 to enclose the lever 152 and, so for as possible, the pivot block 136.

The support bar 121 is connected by clamp nuts 1 5 1 to the piston of a pneumatic ram assembly R, adapted to move the head assembly vertically up and down as hereinafter to be described.

In use, as an insert I is fed along the conveyor 118 it is at a level, relative to the seats 11 3 for the containers, so as to be spaced above the level of the top of a container, The hereinbefore described ram assembly R is operated to lower the vacuum head, with the head in the orientation as shown in Figure 9, into engagement with an insert I fed along the conveyor 118. A valve is operated to apply vacuum to the head 128 to pick up the insert. The roller 149 is then moved upwardly by a cam to permit the rod 47 to move upwardly and the lever 142 to pivot clockwise and thus to cause the pivot block 136 to pivot antiziockwise to tilt the insert at an angle of, for example 550, to the initial position.During this tilting operation the table 10 has moved the workstation from the position at which an insert is picked up from a conveyor 118 to a position at which a can is positioned on the associated seat 113 and then the ram assembly R is operated to move the head downwardly so as to lower the insert into the can.

As shown in Figure-9 the neck of the can is of smaller diameter than the remainder of the can and the tilting of the insert, which insert is of greater longitudinal extent and smaller transverse extent, that the crosssection of the neck of the can permits passage of the insert through the neck of the can.

When the insert is adjacent the base of the can the roller 149 is moved downwardly to cause the lever 142 to rotate in an anti-clockwise direction and the pivot block 136 in a clockwise direction to move the insert to the position shown in Figure 9 in which the longitudinally opposite ends of the insert are in interference engagement with the interior wall of the container.

The vacuum holding the insert to the head 128 is then released and replaced by a pressure above atmospheric pressure, which tends to hold the insert, and hence the can on the associated seat 1 13, whilst the ram assembly R is actuated to withdraw the head from within the can and the head is repositioned at the level ready for engagement with another insert I on the next rotation of-the table.

The container with insert therein then passes to an unloading star wheel 160 where the cans C are removed from the seats 11 3 and fed along an exit conveyor 161.

The exit conveyor 161 leads to a supply conveyor to supply containers to the feed means F of the'apparatus described hereinbefore with reference to Figures I to 7.

The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, or a class or group df substances or compositions, as appropriate, may, separately or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims

CLAIMS:

I. A method of packaging food, beverage or other commodity in a container having an interior volume comprising, providing a insert, having a passage therein to communicate the interior volume of the insert with the exterior thereof and disposed within the container, with a predetermined atmosphere therein, comprising the steps of introducing the insert into the container with the insert containing an atmosphere of an initial composition, changing the atmosphere In the container and thereby changing the atmosphere in the insert.
2. A method according to Claim I wherein the atmosphere is changed by subjecting the interior volume of the container to a sequence of pressure changes to change the atmosphere therein.
3. A method according to Claim 2 wherein the sequence of pressure changes comprises evacuating an initial atmospheric gas from the interior volume of the container and then introducing a further gas of a different composition into the interior volume.
4. A method according to Claim 3 wherein the exterior of the container is subjected to a similar sequence of pressure changes.
5. A method according to Claim 4 wherein the container is disposed within an enclosure with the interior volume of the container in communication with the enclosure and the enclosure is subjected to said sequence of pressure changes.
6. A method according to any one of Claims 3 to 5 wherein the initial atmospheric gas is evacuated by subjecting the interior volume to a pressure below ambient atmospheric pressure and preferablv a vacuum of at least 10" of mercury.
7. A method according to Claim 6 wherein the interior volume is subjected to a vacuum of at least 10" of mercury.
8. A method according to any one of Claims 3 to 7 wherein the further gas of a different composition is introduced into the interior to provide a pressure above ambient atmospheric pressure.
9. A method according to any one of Claims 3 to 8 wherein the sequence comprises performing at least one further evacuation of the interior volume, the or each further evacuation being followed by introduction of a further gas of a different composition from the initial atmospheric gas.
10. A method according to Claim 9 wherein the further gas is introduced into the interior volume more than once and the further gas is of the same composition at each introduction.
1!. A method according to any one of Claims 8 to 10 wherein the pressure above atmospheric pressure at which the further gas is introduced at the or each introduction is at least 20 psi.
12. A method according to any one of Claims 3 to II wherein after introducing the further gas for the or the last time the interior volume is connected to ambient atmosphere.
13. A method according to any one of the preceding claims wherein after said sequence of pressure changes the interior volume of the container is connected to a port through which a commodity to be stored is introduced into the interior volume.
14. A method according to Claim 13 wherein the exterior of the container at this stage is subject to a different pressure than is the interior volume.
15. A method according to Claim 13 or Claim 14 when dependent on Claim 4 wherein the enclosure is connected to a pressure above ambient pressure and the interior of the container is isolated from the interior of the enclosure and in sealing engagement with said port.
16. A method according to any one of Claims 13 to 15 wherein gas of desired composition and pressure is introduced into the container, prior to introduction of said commodity into the interior volume through said port, to provide a counter pressure in the container to facilitate maintenance of container shape and hence sealing engagement with the port.
17. A method according to Claim 16 wherein the counter pressure is released in a predetermined manner after filling his been completed.
18. A method according to any one of Claims I to 12 wherein a commodity to be stored is introduced into~ the interior volume before subjecting the interior volume to the sequence of pressure changes to change the atmosphere therein.
19. A method according to any one of the preceding claims wherein after performance of the sequence of pressure changes the container is transferred to a sealing station whereat the interior volume is sealed from communication with the exterior of the container.
20. A method according to Claim 3 or anv one of Claims 4 to 19 when dependent on Claim 3 wherein the initial atmosphere comprises ambient atmosphere and the further gas comprises nitrogen.
21. A method according to any one of the preceding claims wherein the insert is placed in a container which has a neck, and wherein the insert is of greater longitudinally extent than the cross-section of the neck, by holding the insert in a first orientation whilst causing relative movement between the insert and the container to introduce the insert into the container through the neck and subsequently moving the insert into a second, different, orientation relative to the first orientation to place the insert in a desired orientation in the container.
22. A method according to Claim 21 wherein in the second orientation the insert engages the wall of the container to retain the insert in said desired orientation in the container.
23. A method according to Claim 21 or Claim 22 wherein the neck is circular in cross-section and the insert is elongate having a greater longitudinal extent than transverse extent and in the first orientation the insert is tilted about an tranversely extending axis so as to present a projected longitudinally extent in the direction of introduction which is less than the cross-section of the neck.
24. A method substantially as hereinbefore described with reference to the accompanying drawings.
25. An apparatus for packaging food, beverage or other commodity in a container having an interior volume comprising, providing an insert, having a passage therein to communcate the interior volume of the insert with the exterior thereof and disposed within the container, with a predetermined atmosphere therein, comprising means for introducing the insert into the container with the insert containing an atmosphere of an initial composition and means for changing the atmosphere in the container and thereby changing the atmosphere in the insert.
26. An apparatus according to Claim 25 wherein the means for changing the atmosphere in the container comprises means for subjecting the interior volume of the container to a sequence of pressure changes to change the atmosphere therein.
27. An apparatus according to Claim 26 wherein the apparatus is provided with means to evacuate an initial atmospheric gas from the internal volume and means to introduce a further gas of a different composition into the interior volume.
28. An apparatus according to Claim 27 wherein means are provided to subject the exterior of the container to a similar sequence of pressure changes.
2q. An apparatus according to Claim 28 wherein said means comprise an enclosure within which the container is disposed, with the interior volume of the container in communication with the enclosure and means to subject the enclosure to said sequence of pressure changes.
30. An apparatus according to Claim 29 wherein said means to evacuate initial atmospheric gas from the interior volume comprises vacuum generating means.
31. An apparatus according to Claim 30 wherein said means is capable of generating a vacuum of at least 10" of mercury.
32. An apparatus according to any one of Claims 27 to 31 wherein said means to introduce further gas of a different composition is capable of introducing the gas to provide a pressure therein above ambient atmospheric pressure.
33. An apparatus according to any one of the preceding claims wherein the apparatus comprises a port connectable in communication with the interior of the container through which a commodity to be stored is introduced into the interior volume.
34. An apparatus according to Claim 33 wherein the apparatus comprises means to permit of a different pressure to be applied to the exterior of the container than is applied to the interior volume during said introduction of the commodity.
35. An apparatus according to Claim 33 or Claim 34 when dependent on Claim 29 wherein means are provided to connect the enclosure to a pressure above ambient pressure and to isolate the interior of the container from the interior of the enclosure and connect the interior volume in sealing engagement with said port.
36. An apparatus according to any one of Claims 33 to 35 wherein means are provided to introduce a gas of desired composition and pressure into the interior volume prior to introducing said commodity to provide a counter pressure within the interior volume.
37. An apparatus according to any one of Claims 25 to 32 wherein means are provided to introduce a commodity to be stored into the interior volume before operating said means to subject the interior volume to said sequence of pressure changes to change the atmosphere therein.
38. An apparatus according to any one of Claims 25 to 37 wherein after operating said means to perform said sequence of pressure changes transfer means are provided to transfer the container to a sealing station whereat the interior volume is sealed from communication with the exterior of the container.
39. An apparatus according to Claim 29 or any one of Claims 30 to 38 when dependent on Claim 29 wherein the apparatus comprises a container support, which defines a base part of said enclosure, movable into engagement with a chamber member which defines the remainder of said enclosure so that movement of the container support into sealing engagement with the chamber disposes the container into the enclosure.
40. An apparatus according to Claim 39 wherein the container support is arrestable in a first position in which the enclosure parts are sealing engaged and in which the interior volume of the container is in communication with the interior of the enclosure so that said sequence of pressure changes may be performed.
41. An apparatus according to Claim 40 when dependent directly or indirectly on Claim 33 wherein the container support is then moved to a further position in which the container is moved into sealing engagement with the said port to isolate the interior volume from the interior of the enclosure.
42. An apparatus according to any one of Claims 39 to 41 wherein means are provided to hold the enclosure member in engagement with the container support member during the performance of said sequence of pressure changes.
43. An apparatus according to Claim 42 wherein said means comprises-a stop to prevent movement of the base wall of the container, the stop projecting downwardly from said port.
44. An apparatus according to Claim 29 or any one of Claims 30 to 43 when dependent on Claim 29 wherein a displacing member is disposed within the container, when the container is in position to have said commodity introduced therein, so that when the container is removed from the enclosure and the displacing member is removed from the interior thereof the level of commodity in the interior volume falls below that which it occupied whilst within the enclosure with the displacing member therein.
45. An apparatus according to any one of Claims 25 to 43 wherein an apparatus places the insert in the container, which has a neck, and wherein the insert has a longitudinally extent which is greater thdn the cross-section of the neck, the apparatus comprising a holding means to hold the insert in a first orientation, means to cause relative movement between the holder and a support for the container so as, in use, to introduce the insert into the container through the neck, and means to cause said holding means to move the insert into a second, different, orientation relative to the first orientation.
46. An apparatus according to Claim 45 wherein the holding means comprises a vacuum head to apply a vacuum to the insert to retain the insert in engagement with the head.
47. An apparatus according to Claim 45 or Claim 46 wherein the holding means is mounted for movement about an axis transverse to the direction of said relative movement.
48. An apparatus according to Claim 47 wherein the holding means is pivotable about said axis by a mechanical linkage which extends outwardly of the container, in use, for engagement by an operating member.
49. An apparatus according to any one of Claims 25 to 48 wherein the container is filled by means of a liquid feed head comprising a valve seat member having a plurality of feed passages formed in a monolithic portion thereof.
50. An apparatus according to Claim 4 wherein the feed passages are disposed in a skirt portion of the seat member which extends uninteruptedly around at least part of an arc of a circle and the feed passages being disposed around said circle.
51. An apparatus according to Claim 50 wherein the skirt part extends around a complete circle and is generally annular in a cross-section taken normal to the centre of said circle.
52. An apparatus according to Claim 51 wherein the skirt part is generally frusto-coniccl having a larger diameter towards the discharge end of the feed passages.
53. An apparatus according to Claim 52 wherein each feed passage has a longitudinal axis which lies in a conical surface containing said circle.
54. An apparatus according to Claim 53 wherein the longitudinal axis of each feed passage is inclined in said conical surface relative to a diametric plane thereof containing the axis of the conical surface.
55. An apparatus according to Claim 54 wherein the conical surface has an included angle of approximately 210 and the feed passages are inclined to said diametric plane at an angle of approximately 150.
56. An apparatus according to any one of the preceding claims wherein the head comprises a valve member movable relative to the seal memher to control the change of commodity through the feed passages.
57. An apparatus substantially as hereinbefore described with reference to the accompanying drawings.
58. Any novel feature or novel combination of features disclosed herein and/or shown in the accompanying drawings.