AN ADJUSTER AND A PACKAGING MACHINE COMPRISING SAID ADJUSTER

The present invention relates to an adjuster and to a packaging machine. The adjuster may be for helping to position a top sealing mechanism for a container, but may instead be used for positioning other devices in the packaging machine as well. The invention is applicable to packaging machines and adjusters and positioning mechanisms of various differing constructions and modes of operation.

In a form-fill-seal packaging machine, flat container sleeves to be turned into gable-top cartons are opened and are positioned as open- ended sleeves on a multi-armed mandrel. The bottom of the container is closed and sealed. The container is then stripped from the mandrel into a horizontal endless chain conveyor when it reaches a rotary index position adjacent the conveyor. The container passes to a top pre-breaker station, and if the form-fill-seal packaging machine is also an aseptic machine, then on into a fogging station where a sterilizing agent is sprayed onto the inside surface of the container.

A drying station removes residual sterilizing agent from the container. The container then continues through the machine into a filling station where the container is filled. The container is passed on to a top closing unit where top closing panels are folded inwards, and thence to a top sealing station.

In the top sealing operation, a filled carton, with an open top end, is indexed into the top sealing station. The top flaps of the carton are folded inward to form a gable shaped top, and the two fins are sealed to each other, with heat and/or adhesive, thereby to seal the carton. This operation is typically performed by what is often referred to as a top sealing mechanism having one or more fixed or movable jaws that engage and manipulate the top flaps to seal the carton as described.

During the various operations of the packaging machine, the various mechanical devices used in the machine should be aligned properly with the cartons being moved from one station to the next as the

various operations are performed. Misalignment can occur in various circumstances - for example, chain stretch of the conveyor chain, skewing of the carton carriers, or during initial setup of the machine. Therefore, it is desirable that the various devices used in the packaging machine be adjustable to accommodate various positions and/or orientations of the series of cartons moving through the machine. For example, the top sealing mechanism should be properly aligned with the cartons as the cartons are moved to the top sealing station. Alignment between the top sealing mechanism and the cartons is more feasible if the top sealing mechanism is adjustable.

To this end, it is known to provide a positioning mechanism for correctly positioning any unit located along the conveyor chain, such as the top sealing mechanism. The positioning mechanism includes several adjusters that include threaded adjusting screws. Upon rotation of one or more of the adjusting screws, the top sealing mechanism, or a portion thereof, is movable in a direction parallel to, or perpendicular to, or oblique to, the path of movement of the containers through the top sealing station. The adjusters include a plurality of fixed and moving parts, made typically from stainless steel. If the machine has a c.i.p. (clean-in-place) system, the cleaning fluid may tend to cause seizing-up of screw actions of the stainless steel adjusters, which can be counteracted by an anti-seizing compound. Furthermore, micro-organisms, such as bacteria, which have penetrated into interfaces of the adjusters are difficult for the cleaning fluid to access.

The adjusters typically have various moving parts, and must provide the ability to adjust the position of a mechanism, e.g. a top sealing mechanism, without affecting the cleanliness of particularly an internal environment of the packaging machine, namely a machine having a clean, ultra clean, or aseptic environment. For the purposes of this Patent Application, "clean", "ultra-clean" and "aseptic" internal environments have the following meanings which are based upon shelf lives of products such

as milk and fruit juice and which we believe to be generally understood within the liquid food packaging industry:

"clean" means a shelf life of up to two weeks in the cold chain.

Parts of the packaging machine such as filler nozzles and top sealing mechanism can be unprotected, although they are often in a protective chamber, more for safety reasons than for hygiene.

"ultra-clean" means a shelf life of up to three to six weeks in the cold chain. Parts such as filler nozzles and top sealing mechanism are in a protective chamber for hygiene reasons. The levels of decontamination of the containers before filling and of sterility of air fed to the protective chamber are relatively low.

"aseptic" means a shelf life of up to one year in ambient temperature. Again, parts such as filler nozzles and top sealing mechanism are in a protective chamber for hygiene reasons. The levels of decontamination of the containers before filling and of sterility of air fed to the protective chamber are very high.

It is therefore desirable to provide an adjuster which will not inhibit the cleanliness of the machine in which it is used.

According to one aspect of the present invention, there is provided an adjuster, comprising: a first portion arranged to be fastened to a first structure; a second portion arranged to be fastened to a second structure; a third portion connected to the first and second portions and manually adjustable to change the position of said first portion relative to said second portion such that, as the position of said first portion is changed relative to said second portion, the position of said first structure is changed relative to the position of said second structure; and a sealing arrangement providing a sealing function among said first portion, said second portion, and said third portion.

According to another aspect of the present invention, there is provided a form-fill-seal packaging machine of a desired level of hygiene which is at least

clean, a mechanism for use in relation to a container, and a positioning assembly for said mechanism, said assembly comprising an adjuster which serves to adjust the position of said mechanism in a predetermined sense and which comprises:- a first portion arranged to be fastened to a first structure; a second portion arranged to be fastened to a second structure; a third portion connected to the first and second portions and adjustable to change the position of said first portion relative to said second portion such that, as the position of said first portion is changed relative to said second portion, the position of said first structure is changed relative to the position of said second structure; and a sealing arrangement providing a sealing function among said first portion, said second portion, and said third portion.

Owing to the invention, it is possible to provide an adjuster wherein the risk of leakage of flowable substance outwards and/or penetration inwards by micro-organisms is minimised.

In order that the invention may be clearly and completely disclosed, reference will now be made, by way of example, to the accompanying drawings, wherein:

Figure 1 is a schematic view of a top sealing mechanism for a packaging machine which includes a sealed adjuster;

Figure 2 is a cut-away side elevation taken along the line 2-2 of Figure 1 of the top sealing mechanism;

Figure 3 is a rear elevation of the top sealing mechanism; Figure 4 is a vertical axial section through one of a number of adjusters used in the sealed adjuster;

Figure 5 is a partially exploded perspective view of the adjuster of Figure 4;

Figure 6 is an exploded axial sectional elevation of the adjuster of Figure 4;

Figure 7 is an enlarged axial sectional view of seals among a collar, an adjusting screw and a block of the adjuster of Figure 4;

Figure 8 is an enlarged axial sectional view of a sealing device between a base and a third portion of the adjuster of Figure 4; and

Figure 9 is a side elevation of a form-fill-seal packaging machine including a top sealing station incorporating the top sealing mechanism.

Referring to the drawings, a top sealing station is shown generally at 10, having sealed adjusters 12 similar to each other for changing the position of the top sealing station 10. The top sealing station 10 is used for top-sealing of a container 16. The container 16 is a gable-top carton, which is commonly used for storing consumable fluids, such as juice or milk. The station 10 is in a protected atmosphere chamber of a clean, ultra-clean, or aseptic, form-fill-seal packaging machine.

The top sealing station 10 includes a top sealing mechanism, generally shown at 18, for sealing together the top closure sealing sub- panels 20 of top closure panels 14 of the container 16. This top sealing mechanism 18 may be of a known type. It is desirable that the position of the top sealing mechanism 18 be adjustable to ensure that the top sealing process is correctly carried out - that the sealing sub-panels 20 of the container 16 are properly aligned, for example, when sealed to each other.

To this end, at least a portion of the top sealing station 10 is supported on a positioning assembly 22 that includes at least one adjuster 12. In this embodiment, however, there are three adjusters 12, a first adjuster 24, a second adjuster 26, and a third adjuster 28. The positioning assembly 22 is supported on a machine structure, which may be a part of the frame or another structure of the machine 102 shown in Figure 9. In this embodiment, the positioning assembly 22 is located behind a panel 104 of the machine 102. The first sealed adjuster 24, the function of which will be described later, is secured to the machine structure. The containers 16 are indexed along the machine structure into a position at

the top sealing mechanism 18, where the top sealing process is completed.

The positioning assembly 22 includes generally a first structure or base 30 and a second structure or slider 32. The base 30 is movably connected to the machine structure through the first sealed adjuster 24. The slider 32 is supported on the base 30 for sliding movement relative to the base 30. The slider 32 also supports other components of the top sealing station 10 as shown in Figures 1 to 3, including the top sealing mechanism 18.

In adjustment of the positioning assembly 22, as described below, the slider 32 is movable in one of two directions along the base 30, in a plane parallel to the base 30. The base 30 is also movable in one of two directions along the machine structure, in a plane parallel to the machine structure. Additionally, the direction in which the slider 32 moves relative to the base 30 is perpendicular to the direction in which the base 30 moves relative to the machine structure. This allows the slider 32 to be moved in any direction in a horizontal plane relative to the machine structure. As a result, the top sealing mechanism 18 that the slider 32 supports is also movable in any direction in the plane in relation to the machine structure.

The second and third adjusters 26,28 are similar or identical to each other, and are substantially similar to the first adjuster 24. Each adjuster 24,26 or 28 includes a first portion 34, a second portion 36, and a third portion 38 that is adjustable to set the position of the first portion 34 relative to the second portion 36. The first adjuster 24 is used to set the position of the base 30 relative to the machine structure, and the second and third adjusters 26 and 28 are used to set the position of the slider 32 relative to the base 30.

The second portions 36 of all three adjusters 24,26 and 28 are identical to each other, as are the third portions 38. However, the first portion 34 of the first adjuster 34 is different from the first portion 34 of the

second and third adjusters 26 and 28. Each adjuster 24,26 or 28 includes a block 40; however, the block 40 of the first portion 34 of the first adjuster 24 is fixed to the machine structure by two bolts 42 which extend through apertures 44 which are formed through two outer support portions 46. The remaining parts of the first portion 34 and other components of the first adjuster 24 are identical to the components of the second and third adjusters 26 and 28.

Each block 40 has a tubular portion 48 with a central bore 50. the tubular portion 48 of the first adjuster 24 extends towards the base 30, and the tubular portions 48 of the second and third adjusters 26 and 28 extend towards the slider 32. Separated from the bore 50 by an internal wall 52 of the block 40 is a small chamber 54 of the block 40. The wall 52 forms a shoulder 56 at the inner end of the chamber 54. The outer end of the chamber 54 is open in a direction facing away from the slider 32.

The second portion 36 of each of the adjusters 12 includes a sleeve 58. As shown in Figure 4, the sleeve 58 of the first adjuster 24 is fixed to the base 30 by a bolt 60 received .in a chambered end portion 62 of the sleeve 58. The base 30 has a corresponding shouldered aperture 64, and the bolt 60 is a shoulder bolt 60 which extends into the corresponding shouldered aperture 64. Additionally, the sleeve 58 of each of the second and third adjusters 26 and 28 is fixed to the slider 32 by the same type of bolt 60 which extends through a shouldered aperture (similar to the shoulder aperture 64) formed as part of the slider 32. A tubular portion 66 of the sleeve 58 extends from the end portion 62 in a direction toward the block 40. The tubular portion 66 includes internal screw-threading 68. The outer diameter 70 of the tubular portion 66 is selected so that it can fit within the bore 50 of the tubular extension 48 of the block 40.

The third portion 38 of each adjuster 12 includes an adjusting screw 72. The adjusting screw 72 is received in and supported on the block 40. The adjusting screw 72 has a radially enlarged flange 74 that is received in the chamber 54 of the block 40, with two washers 76. A collar 78, held

to the block 40 by four bolts 80, retains the flange 74 of the adjusting screw 72 in the chamber 54. The adjusting screw 72 is thus supported on the block 40 for rotation relative to the block 40, but is prevented from axial movement relative to the block 40.

The adjusting screw 72 has an externally threaded end portion 82 extending toward the slider 32 (or the base 30, depending on where the adjuster 24,26 or 28 is used), within the bore 50 of the tubular portion 48 of the block 40. The end portion 82 of the adjusting screw 72 is received in the internally threaded portion 68 of the sleeve 58. As a result, rotation of the adjusting screw 72 causes relative axial movement between the adjusting screw 72 and the sleeve 58. In the case of the first adjuster 24, because the adjusting screw 72 is axially fixed to the machine structure and the sleeve 58 is axially fixed to the base 30, rotation of the adjusting screw 72 causes relative axial movement between the machine structure and the base 30. An anti-seize compound is applied to the external screw-threading of the end portion 82. It might also be applied to the flange 74 and the washers 76. With regard to the second and third adjusters 26 and 28, rotation of the adjusting screws 72 causes relative axial movement between the base 30 and the slider 32 because the adjusting screws 72 are axially fixed to the base 30, and the sleeve 58 is fixed to the slider 32.

In the specific positioning assembly 22 illustrated in the drawings, the three adjusters 24,26 and 28 are operable separately or together to provide planar movement of the slider 32 along the plane of the base 30, and the base 30 along the machine structure. Adjustment of the first adjuster 24 moves the base 30 in a direction shown by arrow 84. Adjustment of the second and third adjusters 26 and 28 moves the slider 32 in a direction shown by arrow 86. Adjustment of only one of the second and third adjusters 26 and 28 on either side can produce pivoting movement of the slider 32 on the base 30. As a result, the three adjusters 24,26 and 28 are operable separately or together to provide planar

movement of the slider 32 over the plane of the base 30, and the base 30 along the plane of the machine structure.

A plurality of seals is provided on each adjuster 24,26,28. The seals help to prevent air and foreign matter from entering into internal chambers and passages of the adjuster 24,26 or 28. Also, the seals help to prevent dirt from accumulating at the joints between the moving parts of the adjuster 24,26 or 28. As a result, the seals help to keep the adjuster 24,26 or 28 clean, as is desirable in a clean, ultra-clean, or aseptic environment. Further, the top sealing station 10 is typically used in a machine 102 having a clean, ultra-clean, or aseptic environment, as shown in Figure 9. However, the top sealing station 10 may also be used as part of a machine having less than a clean environment. The seals provide the ability to clean the adjusters 24,26 and 28 by washing, for example, with a c.i.p. internal spray system of the machine 102 without sprayed fluid getting inside the adjusters 24,26 and 28.

The seals of each adjuster 24,26 or 28 include a first seal 88, which in this embodiment is a wiper seal 88, mounted on the collar 78 and sealing the moving joint between the collar 78 and the shaft of the adjusting screw 72, closing the open end of the chamber 54. The wiper seal 88 serves to deter egress into the protective chamber of any anti- seize compound applied to the flange 74 and the washers 76 and to deter ingress from the chamber of micro-organisms to between the collar 78 and the shaft of the screw 72.

The seals of each adjuster 24,26 or 28 include a second seal 90, which is also a wiper seal, mounted on the tubular portion 48 of the block 40, and sealing the moving joint between the block 40 and the sleeve 58, closing the open end of the tubular portion 48 and receiving the sleeve 58. The second seal 90 serves to deter egress into the protective chamber of anti-seize compound applied to the screw-threading of the screw 72 and to deter ingress from the chamber of micro-organisms to between the tubular portions 48 and 66.

The seals of each adjuster 24,26 or 28 include a third seal 92, which is an O-ring seal, mounted on the collar 78 and sealing the fixed joint between the collar 78 and the block 40. The seal 92 serves to deter ingress from the protective chamber of micro-organisms to the chamber 54 via the interface between the block 34 and the collar 78.

The seals on each adjuster 24,26 or 28 include two additional O- ring seals 94 which are part of a sealing device 96. The device 96 also includes a spacer 98 which has circumferential grooves 100 for receiving the O-ring seals 94. Each groove 100 has a lip 102 which helps to retain the seals 94 in the grooves 100. The device 96 is interposed between the base 30 and the end portion 62, to deter accumulation of foreign matter, as well as ingress of micro-organisms, at the fixed joint between those two parts. When the bolt 60 is tightened, the end portion 62 and the base 30 (or slider 32, depending on which adjuster 24,26 or 28 is being used) will be pressed against the spacer 98, compressing the O-ring seals 94 in the grooves 100. This will cause the O-ring seals 94 to deform, and bulge out of the grooves 100. This will reduce the probability of foreign matter settling in the grooves 100, either between the O-ring seals 94 and the lips 102, between the O-ring seals 94 and the end portion 62, or between the O-ring seals 94 and the slider 32 (or base 30 when referring to the first adjuster 24).

The structure and mounting of the O-ring 92 are shown in more detail in Figure 7. The O-ring 92 is captured initially in a groove 104 in the collar 78. The collar 78 has an outer lip 106 that projects part-way toward the mating surface of the block 40 and that helps to retain the O-ring 92 in the groove 104.

When the collar 78 is clamped down tight against the block 40, lip 106 does not engage the mating surface. The dimensions of the O-ring 92 are selected so that a portion of the O-ring 92 bulges out of the groove 104 in the space between the lip 106 and the mating surface. Again, the possibility of foreign matter, for example micro-organisms, migrating into

the groove and being retained there, either between the O-ring 92 and the lip 106, or between the O-ring 92 and the mating surface, is lessened. Therefore, each adjuster 24,26 or 28 is maintained in a cleaner state.

The sealing device 96 is used not only between the slider 32 and each sleeve 58 of the adjusters 26 and 28 but also between other parts of the adjusters 24,26 and 28 as well. Two sealing devices 96 are used between the first adjuster 24 and the machine structure, as shown in Figures 1 to 5. The bolts 42 extend through the sealing devices 96, and the devices 96 are located between the outer support portions 46 and the machine structure.

There are two more sealing devices 96 used between the second and third adjusters 26 and 28 and the base 30. The second and third adjusters 26 and 28 also have bolts (not shown), similar to the bolts 60, which extend through the bottom of the base 30 and through the sealing devices 96 up into the blocks 40 of the second and third adjusters 26 and 28. The second and third adjusters 26 and 28 are thereby secured to the base 30.

The positioning assembly 22 also includes a set of positioning bolts 110. The positioning bolts 110 extend through the base 30, and can optionally each have a washer 112. The positioning bolts 110 are received into corresponding slots (not shown) in the machine structure and guide the movement of the base 30 along the machine structure.

There are also additional washers 114 and 116 which can be used for the bolts 42 and the bolts 80. These washers may be in the form of seals to deter ingress of micro-organisms to between the bolts 42 and the top surfaces of the portions 46 and to between the collar 78 and the bolts 80.