GB2391835A - Formation of concertina shaped box - Google Patents

Abstract

An apparatus and method are disclosed in which a box blank is erected from a pre-form. Also disclosed is a method in which a sheet is folded and compressed to form a concertina shaped box. Apparatus for forming the concertina shaped box is discussed in detail.

Description

1 - CARTON

The present invention relates to cartons, or more 5 particularly to cartons made from paperboard, cardboard, plastic or other foldable sheet materials, and a method and apparatus for manufacturing a shaped part of or for such cartons.

Cartons are commonly used in the packaging of 10 consumer products, such as confectionery and cosmetics.

Often the cartons, or a part thereof, are shaped to provide the packaging with enhanced visual appeal and distinctiveness. The present invention seeks to provide a new method and apparatus for providing a shaped part 15 of or for a carton.

According to a first aspect of the present invention there is provided a method for producing a shaped carton or part therefor, the method comprising: providing a blank; erecting the blank to produce a pre 20 form; and forming said pre-form to bring it closer to a final shape.

According to a second aspect of the present invention there is provided an apparatus for producing a shaped carton or part therefor, the apparatus 25 comprising: means for supplying a blank; means for erecting the blank to produce a pre-form; and means for forming the pre-form to bring it closer to a final shape. Thus in accordance with the present invention, a 30 blank is first erected to produce a pre-form. In general, this will involve transforming a 2-dimensional blank into a 3-dimensional structure. The pre-form is then formed to cause it to more closely conform to a desired final shape. This final shape will generally 35 correspond to the shape of the carton, or part thereof, which the part is to define.

It has been found that by shaping a pre-form which

i À 2 has already been erected in this way, more complex shapes may be obtained than using conventional techniques, in which shaping is carried out as, or before, a blank is erected into a 3-dimensional form. In 5 this way, the present invention may also provide a more flexible process, as the erection and shaping of the pre-form take place in separate stages. For example, different shapes may easily be produced by making appropriate changes to the forming apparatus, and 10 without needing to modify the erection apparatus.

The shaped pre-form may be a carton, or may be combined with other parts in order to produce a carton.

For example, the shaped part may define a lid or base of a carton, or part of a lid or base.

15 The blank may be formed from any suitable material, but preferably is formed from cardboard, plastic or paperboard. The size and shape of the blank will depend upon the nature of the pre-form which it is to form.

Preferably the blank includes means to facilitate its 20 erection into a pre-form, such as fold lines, tabs and so on.

Preferably the blank is stored in a storage location, such as a magazine, and delivered from the storage station to an erection station for erection into 25 a pre-form.

The erection station may be of any suitable type capable of erecting a blank to produce a pre-form of the type required. However, generally the forming the pre-

form comprises transforming a blank from a 2-dimensional 30 form to a 3dimensional form. The most appropriate type of pre-form will depend upon the intended final shape of the pre-form, and the shape and form of the carton or part thereof which it is to define. For example, the pre-form may simply comprise a band, ring, box-like 35 frame or the like, for example for use in producing a shaped part which is to form the walls or rim of a carton. In a simple case, therefore, erecting the blank

- 3 - may thus simply involve transforming the blank from an open configuration to a closed configuration, e.g. by joining the ends of the blank to form a closed shape such as a ring. In a preferred embodiment, the pre-form 5 is a tray, most preferably a rectangular tray. Standard tray erecting machinery may be used for this purpose.

The pre-form may be transferred in any suitable manner from the erection station to the forming station, but preferably a conveyor is provided for the purpose.

10 Preferably means are provided for supplying the preforms to the forming station at a desired rate. Such means may include, for example, a gate provided upstream of the forming station, behind which pre-forms are held in a queue until being released to enter the forming 15 station at a desired rate.

Preferably, the preforms are supplied to the forming station in a stepwise manner. Preferably this is achieved by a reciprocating transfer mechanism.

The transfer mechanism preferably comprises a 20 reciprocating gripper mechanism which grips a preform at a first position and moves to a second position where it releases the preform and returns to its first position to grip a second preform. A plurality of such mechanisms could be provided such that a succession of 25 preforms may be progressively moved from the delivery means to the forming station.

Forming the pre-form will typically involve imparting a more complex shape to the whole or part of a pre-form. For example, shaping may be applied to only 30 selected sections e.g. sides, corners or surfaces of the pre-form. Preferably the pre-form is folded into a desired shape. Preferably the preform is provided with crease lines to facilitate such folding. In particularly 35 preferred embodiments, the fold lines are arranged such that the a pre-form can be folded into a corrugated configuration.

- 4 - In a particularly preferred embodiment a rectangular tray is provided with a plurality of folds which define a plurality of parallel ridges and grooves, so defining a plurality of corrugations, whereby the 5 tray can be collapsed and expanded in the manner of a concertina. Forming of the pre-form may be carried out in one or more stages. For example, separate forming steps may be used to shape different parts of the pre-form.

10 However, preferably forming is effected at a single forming station.

Preferably the pre-form is shaped using a form whose shape conforms to the desired shape of the formed product. In the preferred embodiment, the form 15 comprises a forming block around which the preform is deformed. Where a corrugated product is to be formed as discussed above, the block comprises a corrugated forming surface. In the case of a corrugated, 20 collapsible tray, the base and opposed sides of the forming block are corrugated.

This is in itself a novel way in which to form a corrugated product, so from a further aspect, the invention provides a method of forming a corrugated 25 product comprising deforming a creased blank into contact with a form having a series of corrugations formed on the surface thereof.

The pre-form may be caused to conform to the surface of the form in any suitable manner. Preferably, 30 however, shaping means are provided to press the pre-

form into contact with the form.

Preferably the pre-form is held on the form, which is preferably movable from a position for receiving a pre-form, e.g. from the transfer mechanism described 35 above to a forming position. The form may be rotatably or more preferably linearly movable.

Preferably the forming block is provided with means

for retaining the pre-form as it is moved into the forming position. In the case of a tray or the like, the form may locate within the tray and the retaining means be formed by one or more retractable members which 5 engage the tray, for example the ends of the tray.

The retaining means may be released as soon as the preform is brought into engagement with the form during forming. This is desirable and in many cases necessary as forming of the pre-form will generally result in a 10 reduction in its overall dimensions as it is caused to conform to the forming block.

Preferably the shaping means is movable by suitable drive means towards the form for urging the pre-form into engagement with the form.

15 The shaping means may be a unitary structure which moves as a body into engagement with the form. However, it has been found, particularly when forming corrugations, that deformation should occur progressively so as to prevent tearing of the preform.

20 When forming corrugations, therefore, shaping members such as shaping teeth should progressively engage the form to form the corrugations. The deformation may start in any suitable location and proceed from there progressively, in a ripple like 25 manner It could, for example start at one end of the form and work along the form in one direction, but preferably it starts in a middle region of the form and works outwardly therefrom in both directions.

Preferably the shaping members are moved in the 30 appropriate sequence by cam means associated with respective shaping members.

Preferably guide means is provided for guiding the shaping members towards the form. In a preferred embodiment, the shaping members are provided with 35 respective pins which ride within grooves as the shaping members move towards the form.

Preferably the shaping members are configured to

- 6 - move not only inwardly towards the form but also laterally in the direction of shortening of the preform.

This allows the shaping member" to engage the preform more precisely and assist in its shortening, further 5 reducing the risk of it tearing.

The shaped pre-form may be released from the form in any suitable manner. Preferably the shaped preform is stripped from the form as the form returns towards the position at which it picks up a new preform. For 10 example, the stripping means may be arranged to intercept the sides or the ends of the pre-form.

Preferably, therefore the stripping means comprise means which may deflect as the form passes through them in one direction and not the other, for example spring mounted 15 arms. Preferably the forming station further comprises ejection means for ejecting the shaped pre-form from the forming station. Preferably, the ejection means is arranged to receive a shaped pre-form as it is released 20 from the form. Most preferably the ejection means is arranged to feed the shaped pre-forms to outfeed means, such as a conveyor, for transferring the shaped pre forms away from the forming station for further processing. 25 The ejection means may be of any suitable form. For example, it may comprise a conveyor, but more preferably comprises a reciprocating table. Preferably the table is arranged above the forming station and is moved in synchronization with the form such that it catches the 30 shaped preform as it falls from the form and carries it to an out feed.

Preferably the formed pre-form undergoes a further finishing step to help to maintain the shape imparted to it in the forming stage. For example, the shaped pre 35 form may be combined with one or more other parts, to help to retain its shape. For example, where the formed pre-form is in the form of a ring, one or more end Ir _ _

- 7 - cap(s) may be provided. In one embodiment, the finishing step thus comprises joining the shaped pre from to one or more additional parts.

However, as mentioned above, shaping the pre-from 5 preferably involves forming a concertina-like tray. The Applicants have found if the folds are subsequently compressed, the tray will retain its shape more effectively. Preferably therefore the finishing step comprises compressing the shaped preform, or at least a 10 part thereof.

This is in itself a novel and inventive process, so from a further aspect, the invention provides a method of forming a concertina-like body from cardboard, paperboard, plastics or other foldable sheet material 15 comprising folding the sheet material to form a series of corrugations therein and then compressing the folded material in a direction perpendicular to the corrugations to collapse the corrugations.

Preferably the compression occurs at a separate 20 station with means being provided for transferring the formed pre-forms to a compression station. Such means typically may comprise a conveyor having a gate operable to allow entry of a pre-form to the compression station at a desired time.

25 The pre-form may be compressed in any suitable manner. Preferably preform is confined as the compression is carried out so as to limit its movement in directions other than the direction of compression.

For example, where the shaped pre-form is a tray having 30 corrugated base and sides, the compression may occur in a box-like chamber to allow confinement of the shaped sides and base.

The pre-forms may be provided to the compression chamber in any manner. In a particularly preferred 35 arrangement, the pre-form is pushed into the compression chamber using the compression member.

The compressed pre-form may be removed from the

- 8 - compression station as desired. Preferably the compression station comprises means for releasing the formed pre-form when it has been compressed to a predetermined extent. For example, a sensor may be 5 provided to determine when the compressed pre-form has attained a predetermined dimension in a given direction, thus triggering a gate to open. Preferably the pre-form is released in the direction of compression. In this way, the pre-form may eject itself from the compression 10 station as the compressing force is released. Preferably the end wall of the compression chamber comprises a gate through which the compressed preform is ejected.

The pre-form may then undergo any further processing as required to produce a finished carton. For 15 example, if the pre-form defines a shaped part for a carton, the it may be combined with other parts to form the carton.

Some preferred embodiments of the present invention will now be described by way of example only and by 20 reference to the accompanying drawings in which: Figure 1 shows a blank for use in forming a shaped tray in accordance with a first embodiment of the invention; Figure 2 is a side perspective view of a pre-form 25 erected from the blank of Figure 1 in accordance with the first embodiment of the invention; Figure 3 is a perspective view of the pre-form of Figure 2 after shaping in accordance with the present invention; 30 Figure 4 is a top plan view of the shaped tray shown in Figure 3; Figure 5 shows a blank for use in forming a shaped pre-form in accordance with a second embodiment of the invention; 35 Figure 6 shows the blank of Figure 5 erected to form a pre-form; Figure 7 shows a side perspective view of the pre \

- 9 - form of Figure 6 after shaping in accordance with the present invention; Figure 8 is a top plan view of an apparatus for forming a shaped tray in accordance with the first 5 embodiment of the invention; Figure 9 is a perspective view from the top and side of an infeed means in accordance with the present invention; Figure 10 is a top plan view of the infeed means of 10 Figure 9; Figure 11 is a cross-sectional view along the line 11-11 of Figure 9; Figure 12 is cross-sectional view along line 12-12 of Figure 10; 15 Figure 13 is a bottom plan view of the infeed means of Figure 9; Figure 14 is a cross-sectional view of the apparatus of Figure 8 along the line 14-14 in the forming station 72 with certain details omitted for 20 clarity; Figure 15 is a schematic cross-sectional view of the forming apparatus along the line 15-15 of Figure 8; Figures 16-19 are views showing certain aspects of the forming apparatus of the present invention in more 25 detail; Figure 20 is a top perspective view illustrating the ejection apparatus of the present invention; Figure 21 is a top plan view of the ejection apparatus shown in Figure 20; 30 Figure 22 is a cross-sectional view along the line 21-21 of Figure 21; Figures 23-25 are views illustrating certain aspects of the compression station in more detail; and Figures 26 a-d are schematic diagrams illustrating 35 the stages in the operation of the forming station of the present invention.

Figure 1 shows a blank 1 for producing a shaped

- 10 carton in accordance with a first embodiment of the present invention. The blank is intended to be erected to form a pre-form in the form of a rectangular open tray. The blank includes side portions 2,4, base portion 5 6 and end portions 8 for defining the corresponding parts of the erected tray. The blank also includes gluing tabs 10 for adhering to areas 12 of the end portions 8 during erection.

The blank is provided with two straight creases 14 10 extending in a longitudinal direction between the respective side portions 2, 4 and the base portion 6, and transverse creases 16 extending between the tabs lo and end portions 8 and the side and base portions 2,4,6 to allow the blank 1 to be erected into a tray.

15 The blank also comprises a plurality of transverse creases 18 along its length extending across the base and side portions (2,4,6) and two sawtooth creases 20 extending longitudinally of the blank 1 adjacent the creases 14. The creases 18, 20 facilitate the 20 subsequent shaping of the erected pre-form as will be described in more detail below.

Figure 2 shows the blank of Figure 1 erected to produce a tray pre-form 30. This can be performed on standard tray erecting machinery such as SKA machinery.

25 Figures 3 and 4 illustrate the pre-form 30 after it has been shaped in accordance with the present invention. The transverse creases 18 are folded alternately away from or towards the centre of the tray. The 30 creases 18 which extend into the plane of the page are denoted in dotted lines in Figures 3 and 4, while those extending out of the plane of the page are shown using solid lines. In this way, the sides 2,4 and base 6 of the tray are provided with a plurality of folds or 35 corrugations 44 defining alternate recesses 46 and grooves 42. The tray may be collapsed or expanded in the direction of the arrow A-A by moving the ends 8

towards or away from one another in a concertina-like fashion. Details of how the preform is shaped will be given further below.

5 Figure 5 shows a blank for producing a shaped part of a carton in accordance with a further embodiment of the present invention.

In this embodiment, the blank 50 is in the form of trapezoidal strip, with tabs 52 for use in erecting the 10 blank to produce a dished annular pre-form 60 as shown in Figure 6. The blank 50 is provided with precreases 64 for facilitating shaping of the pre-form.

Figure 7 shows the pre-form 60 after shaping in accordance with the present invention. The pre-form has 15 been provided with a plurality of creases 64. The creases represented in solid lines extend out of the plane of the page, while those shown in dotted lines extend into the plane of the page. In this way, two folds 62 are provided, extending towards the centre of 20 the pre-form. A shaped pre-form of this type may suitably be joined with other components such as an end cap or e.g. a lid to define a shaped container or carton. In an alternative embodiment (not shown) the pre-form could be a quadrilateral - i.e. a box-like 25 frame instead. The corners of the frame could then be folded. An apparatus for forming the shaped carton of the first embodiment shown in Figures 3 and 4 will now be described in more detail with reference to Figures 8-26.

30 As shown in Figure 8, the apparatus comprises an erection station 70, a forming station 72 and a compression station 74. The erection station 70 is a standard tray erecting machine and produces a tray preform as shown in Figure 2.

35 A conveyor 76 is provided for supplying erected pre-forms from the erection station 70 to the forming station 72. The conveyor 76 comprises a first part 78

- 12 and a second part which is split into two parallel conveyors 80,80'. Means 84 is provided for directing erected pre-forms moving along the conveyor portion 78 towards either conveyor 80 or 80'. In this way, the 5 erected pre-forms are divided into two streams for subsequent processing.

The directing means comprises a gate 86, and respective pushers 88, 88', the gate releasing alternate preforms 4 to pusher 88.

10 The apparatus provided downstream of this point for the processing of the two streams of pre-forms is identical, and will thus be described with reference to the first stream of pre-forms which moves along conveyor 80. The corresponding parts associated with the second 15 stream are represented using the same reference numerals as those used in respect of the first stream but with a prime. In-feed means 90 is provided in the shaded region between the end of the conveyor 80 and the forming 20 station 72 for controlling the rate at which pre-forms are supplied from the conveyor 80 to the forming station 72. A sensor 92 is provided upstream of the infeed means 90 and signals from the sensor can be used in a feedback circuit to control the rate of output of the 25 erection station 70 in response to the rate of build up of pre-forms at the end of conveyor 80 awaiting transfer to the in-feed means 90.

An outfeed conveyor 94 is provided to transfer shaped pre-forms from the forming station 72 to a 30 compression station 74. The compression station comprises a plunger 96 and a compression chamber 98. A sensor 100 is provided upstream of the compression station 74 to monitor the build up of shaped pre-forms on conveyor 94 awaiting compression. A collection bin 35 102 is provided for collecting shaped and finished pre-

forms as they are ejected from the compression chamber 98.

- 13 Figures 9-13 show the infeed means in more detail.

The infeed means comprises three pairs of jaws 110, 112 and 114 which are mounted on respective inner shafts 116 and outer shafts 117. The jaws 110, 112, 114 are 5 fixedly mounted to the shafts 116, 117 so as to be rotatable between a closed configuration as shown in Figure 9 and an open configuration by rotation of the shafts 116, 117. In Figure 12 one jaw of a pair of jaws i 110 is shown in the open configuration and the other 10 closed for the purposes of illustration, although normally both jaws in a pair will either be open or closed. The outer shafts 117, 117' are mounted to respective carriages 132, 132' by means of journals 134, 15 134'. The inner shafts 116, 116' are mounted to a single central carriage 131 by journals 135, 135'. The carriages 132', 131 and 132 are slidable in the direction of arrow D-D on rails 136', 137 and 136 from a first position closer to the forming station as shown in 20 Figures 9 and 12, to a second position closer to the conveyors 80, 80'. Rails 136, 136' and 137 are mounted to a base plate 140.

Apertures 154, 154' are provided in the base plate 140 and guide tongues 156, 156' are provided on either 25 side of the apertures 154, 154'. Support rails 142, 142' are also mounted to the base plate between the two sets of jaws 110, 112, 114 and llO', 112' and 114' for purposes to be described in more detail below.

As may be seen more clearly in Figure 13, the 30 carriages 132, 132' are linked to the central carriage 131 by means of members 146 and 148 respectively. A connecting rod 150 connects the central carriage 131 to a pin 153 of crank arm 152. Crank arm 152 is mounted on a fixed shaft 151. In this way, the carriages 132', 132 35 and 131 are moved together as a result of movement of the connecting rod 150 under the action of the crank arm 152. The crank arm 152 is also provided with a pin 512

- 14 for purposes to be described below.

The movement of the jaws 110, 112, 114 from the open to the closed position is controlled using three actuating cylinders. Two cylinder 118, 118' are mounted 5 on the carriages 132, 132' respectively. A third cylinder 119 is mounted on the central carriage 131.

The first and second actuating cylinders 118, 118' act on the outer shafts 117, 117' by means of actuating arms 124, 124'. The third actuating cylinder 119 acts on the 10 inner shafts 116, 116' simultaneously by means of an actuating arm 120.

The arm 120 is connected to the respective inner shafts 116, 116' by means of links 122, 122'. As may be seen more clearly in Figure 12, when arm 120 is in a 15 raised position, the links 122, 122' are in the inclined positions 122A, 122'A. When the arm 120 is lowered, the links 122, 122' are moved to a second horizontal position 122B, 122B'. Movement of the link 122 from position 122A to 122B causes the shaft to rotate 20 clockwise causing the inner jaws 110, 112, 114 to open.

Similarly, movement of link 122' from position 122A' to 122B' causes the shaft 116' to rotate anticlockwise, and the inner jaws 110', 112' and 114' to open. As the arm 120 lowers, the shafts 116, 116' rotate in the opposite 25 sense causing the jaws to close.

The outer cylinders 118, 118' are similarly linked to the shafts 117, 117' by means of links 126, 126' attached to arms 124, 124'. For the purposes of clarity, the arms 124, 124' and cylinders 118, 118' are 30 omitted from Figure 11, which shows only the raised and lowered positions of links 126, 126'. When the arms 124, 124' is in a lowered position, so are the links 126, 126'. As the arms 124, 124' are raised, the links 126, 126' are raised, causing the shaft 117' to rotate 35 clockwise and shaft 117 to rotate anticlockwise to close the jaws and collecting arm. Conversely, as the arms 124, 124' are lowered again, the links 126, 126' are

' - 15 lowered once more, causing the shaft 117 to rotate anticlockwise and shaft 117' to rotate clockwise to open the jaws.

The cylinders actuate in response to movement of 5 the carriages 132, 132', 131 e.g. using an appropriate switching arrangement. Thus as the carriages begin to move from the first to the second position, the cylinders are configured to open the jaws and connecting arms, and when the carriages begin to move from the 10 second to the first position, the jaws and connecting arm close.

Operation of the infeed means will now be described with reference to the left hand infeed means 90 of Figure 10. For the purposes of illustration, the 15 collector arm 130 is shown in both the first position 13OB closer to the end of the conveyor 80 and the second position 130A closer to the forming station 72, corresponding to the first and second positions of the carriage 132. When the carriage 132 is in the first 20 position, the pairs of jaws 110 are closed and located either side of the aperture 154 (position E in figure 10). The pairs of jaws 112 and 114 are respectively situated either side of positions D and C, and the collector arm at position 13OB.

25 As the carriage 132 slides to the second position closer to the conveyor 80, the jaws open. In the second position the collector arm 130 is located around the outer edge of a pre-form 180 at the end of the conveyor in position A. The jaws 110, 112 and 114 move 30 respectively to positions D, C and B. The carriages 132, 132' and 131 then return to the first position closer to the forming station, simultaneously closing the jaws 110, 112, 114. In this way, the pre-form 180 is moved from position A to position B by jaws 114.

35 The jaws then open and the carriage 132 moves to the second position once more. The pre-form 180 is left at the intermediate position B supported on the guide

l - 16 rails 142. The jaws close again, with the pair of jaws 114 closing around the pre-form 180 in location B. At the same time, the collector arm 130 closes around the next pre-form which has moved in to the place vacated by 5 the pre-form 180 at the end of conveyor 90.

The carriage 132 then returns to the first position thus transferring preform 180 to position C and a new pre-form to position B. Once again, the jaws open leaving the pre-forms supported on the guide rails 142, 10 and the carriage 132 returns to the first position. In the first position the jaws close once again, this time with the jaws 112 closing around preform 180 in position C, jaws 114 closing around the new pre-form in position B. while the collector arm 130 closes around 15 the next preform situated at the end of conveyor 80.

This process is repeated until pre-form 180 reaches position E in which it is supported above the aperture 154 by jaws 112, with the subsequent pre-forms held by jaws 112 and 114 in positions D and C. In this 20position, the preform is ready to be supplied to the forming station 72.

The forming station will now be described in some more detail with reference to Figures 14 and 15.

As can be seen in Figure 14, a forming block 210 is 25 mounted on a forming arm 200 supported on a beam 203.

The beam 203 is mounted for reciprocating vertical movement on rails 205 by journals 201 such that the forming block 210 may be raised and lowered in the direction of arrow F-F on a vertical axis which passes 30 through the centre of aperture 154 of the infeed mechanism. The arm 200 is thus reciprocal between a first raised position G in which the forming block 210 in located above the aperture 154 and a second shaping 35 position H in which the forming block 210 is located within a shaping area 220, as the beam 203 slides from position I to position J.

- 17 When a pre-form is held between jaws 110, it is thus in a position to be received by the forming block 210. A pair of spring mounted lever arms 222 are mounted 5 to the underside of base plate 140 of the infeed means 90. The arms 222 are rotatable about respective axis 224 downwardly from the position shown in Figure 14 through 90 to a vertical position to allow passing of the forming block 210 in a downward direction as it -

10 moves from G to H. However, they are not rotatable in an upward direction towards the base plate 140 for the position shown in Figure 14. The horizontal distance separating the arms when in this position is chosen -

appropriately so that the arms will engage a pre-form 15 mounted on the forming block 210 as it moves upwards -

from the forming location 220, but still allowing movement of the forming block 210, as described in more detail below. The arms are resiliently biased by spring means (not shown) to return to the horizontal position; 20 parallel to the base plate 140 as shown in Figure 15.

The relative positions of the parts of the forming station are shown more clearly in Figure 15. Here it may be seen that the infeed means is located at the highest level, followed by ejection means 226 (not shown in 25 Figure 14) with the shaping area 220 at the lower-most level. The arrow A represents the direction of input of pre-forms to the forming station 72 from the conveyor 80, and the arrow B indicates the direction of flow of shaped pre-forms out of the forming station 72 to output 30 conveyor 94.

Figures 16A and 16B illustrate the configuration of the forming block in more detail. The forming block 210 is generally in the shape of a rectangular block having corrugated sides 230, 232 and base 234. The 35 corrugations define projecting portions 237 and recessed portions 235. The block 210 has end plates 236, 238 which are extendable relative to the ends 239 and 241 of

- 18 the block 210. In Figure 16A, the plate 236 is shown in the retracted position while the plate 238 is in the extended position, while in Figure 16B, both plates 236 and 234 are in the extended position.

5 When the forming block is in the raised position G shown in Figure 14, the end panels 234, 236 will normally be retracted. The forming block 210 may then be moved downwardly on arm 200 to the level of the infeed means 90. In this position, the end plates 234, 10 236 are extended to receive a pre-form retained in the jaws 110. The jaws 110 will then open allowing the pre form mounted on the forming block 210 to continue downwards towards the position H in the forming area 220. 15 The forming area 220 will now be described in more detail with reference to Figure 17-19. The forming area 220 contains three sets of shaping means 240, 242 and 244 for shaping respectively the sides 2, 4 and base 6 of a pre-form held on the forming block 210 when in 20 position G. In this position, as shown in Figure 17, the forming block 210 is located between the two sets of shaping means 240, 242, and above shaping means 244. The construction of each of these parts of the shaping means is identical, and the details of shaping means 242 will 25 now be described in more detail by way of example.

Shaping means 242 comprises a set of shaping teeth 250 which may be seen more clearly in Figure 18. One shaping tooth 250 is associated with each of the recessed portions 235 of the side 232 of the forming 30 block 210. An upwardly extending pin 252 is provided attached to the top of each shaping tooth 250 and rides in a respective groove 254 provided in a guide plate 258. The grooves 254 are shaped so as to direct the shaping teeth 250 towards the centre of the forming 35 block 210. No guide means or pin is associated with the central tooth, which is allowed to ride straight forward into the recess provided at the centre of the side 232

of the forming block 210.

Each shaping tooth 250 is attached to a spring 260.

As shown in Figure 17, a set of cams 262 is provided mounted to an axis 264. The cams 262 act on the rear of 5 the teeth 250 to drive the shaping teeth 250 towards the shaped surface 232 of the forming block 210 against the force of return springs 260. The cams 262 are shaped and positioned such that the teeth 250 move forward at different times, as will be discussed further below.

10 As shown in Figure 19, the shaft 264 is linked to corresponding shafts 268 and 270 associated with the shaping means 244 and 240 whereby the cams associated with the shaping means for each of the sides and base of the forming block 210 are synchronized to act on the 15 associated springs and hence the shaping teeth for each of the sides and base at the same time.

After forming the corrugations in the preform, the shaped preform is stripped off the forming block 210 by the spring arms 222 as it moves upwardly. The shaped 20 preform is then moved out of the shaping section 200 by ejection means 226 shown in more detail in Figures 20 22. The ejection means comprises trays 300, 300' slidably mounted on inner and outer rails 304, 304 ' and 25 305, 305' respectively by means of outer carriages 306, 306 ' and a single inner carriage 307. The rails 304, 304' and 305, 305 ' are mounted to outer and inner supports 301, 301' and 303, 303'. The trays 300, 300' are therefore slidable towards and away from inclined 30 chutes 302, 302' fixed to the supports 301, 301' and 303, 3 03 '.

The inner carriage 307 is attached by a connecting rod 308 to one end 506 of a reciprocating arm 310 which is rotatable with a shaft 520. Reciprocation of the arm 35 308 will cause the carriage 307 and hence the trays 300, 300' to slide on the rails 304, 304', 305, 305' towards or away from the fixed chutes 302, 302 ' under the action

- 20 of connecting rod 308.

The compression station 74 will now be described in more detail with reference to Figures 23-25. An entry gate 400 is mounted to control movement of shaped pre 5 forms along the conveyor 94 into the compression station 74. The compression station comprises an end stop 95 provided at the end of conveyor 94. A plunger 98 corresponding in shape and size to the end 8 of the shaped pre-form is mounted by means of a carriage 422 on 10 a rail 420 which extends parallel to the end stop 95 across the conveyor 94 and into a compression chamber 402. In this way, the plunger 98 is slidable in the direction of arrow A-A into the compression chamber.

As shown in Figure 25, the compression chamber 15 comprises side walls 412 and 414, and a roof 416. A blind ended groove 418 is provided in the roof 416 to allow the carriage 422 to continue along the rail 420 into the compression chamber 98. The compression chamber also comprises an exit gate 406. The exit gate 20 406 is held in an rained position in which it prevents ejection of the pre-form during compression by a piston 408. When the carriage reaches the end of the groove 418, this is detected by a sensor 410 mounted to the end of the rail 420, the piston 408 retracts thereby opening 25 the gate 406 to open. The pre-form then ejects under its own resilience and is collected in collection bin 102. The interconnection of the various parts of the forming station 72 and its sequence of operation will 30 now be described in more detail with reference to Figures 26a-d.

Drive for the system is provided by a drive shaft 500 having a driving arm 498 mounted thereto. The drive arm 498 is connected to the shaft of a drive arm 310 by 35 links 501, 502 which are connected through a pin coupling 504. One end of the arm 501 is fixed at an angle of 90 relative to the shaft 520.

- 21 A link 505 connects the other end of the link arm 501 to the beam 203 of the forming arm 200, for reciprocating the beam along the rails 205.

The ejector arm 520 is connected to the shaft 151 5 of crank arm 152 of the infeed mechanism by a pin coupling 508, link arm 510, pin coupling 512 and link 513. A pin coupling 153 couples the crank arm 152 to the connecting rod 150 to the carriage 131 of the infeed means 90 for sliding the carriage 131 from the first to 10 the second position as previously described.

A pin coupling 506 links the drive arm 310 to the connecting arm 308 for movement of the tray 300 of the ejection means 226 towards and away from inclined chute 302. 15 Operation of the apparatus to produce a shaped pre form in the form of a corrugated tray in accordance with the first embodiment of the first invention will now be described. A blank 1 is first erected into a tray preform in 20 erection station 70. The erected pre-form 30 proceeds along conveyor 78 and is fed onto one or other of the conveyors 80, 80' by the pushers 88, 88'.

Pre-form 30 continues along conveyor 80 until it reaches the infeed means 90 which progressively moves 25 the preform through to the forming station 72 to position E (Figure 10) where it is held by the jaws 110 over the aperture 154, as previously described. The reciprocating movement of the carriages 131, 131', 132 is provided by the aforementioned linkage.

30 The preform may then be shaped in a sequence now described in more detail with reference to Figures 26 A D. As shown in Figure 26A, the drive arm 498 starts in the top dead centre position. In this position, the 35 forming arm 200 is in a raised position, the infeed means 90 is in the first position in which the jaws 110 hold the erected pre-form 30 over the aperture 154 in

- 22 the base plate 140 of the infeed means 90, and the ejection tray 300 is in a position adjacent the ejection chute 302. The end plates 236, 238 of the forming block 210 are in their retracted position.

5 The drive arm then rotates clockwise 90 to the position shown in Figure 26B. By virtue of the various linkages, this movement causes the forming arm 200 to move downwardly, and the arms 150, 308 to move to the left, to the positions shown in Figure 26B.

10 During the downward movement of the forming arm 200, the forming block 200 moves into the preform and its end plated 236, 238 extend to retain the preform.

At the same time the jaws 110 release to allow the preform to be pushed down by the arm 202.

15 The drive arm 498 then rotates through a further 90 to the bottom dead centre position shown in Figure 26C. This moves the forming arm 200 downwardly through the spring mounted arms 226 to the lower position where the forming block 210 is located between the three 20 shaping means 240, 242 and 244.

The ejection tray 300 moves further away from the inclined chute 302, while the infeed means 90 remains substantially in its second position.

When in the forming sation, the driving shafts 264, 25 270 and 268 rotate, causing the cams 262 to rotate. As described above, the came drive the teeth 250 forward towards the sides and base of the pre-form supported on the forming block 210 to form the corrugations. The movement of all three sets of teeth 2SO is synchronized.

30 The cams 260 are configured and arranged so that the central tooth 250 contacts the pre-form first, urging it towards the recessed portions 235 of forming block 210. The preform then folds along the creases 16, 18 to form a corrugation. The shaping continues with 35 the pair of teeth 250 arranged next outwardly towards the ends of the forming block and so on in an outward ripple-type effect. This method of forming allows the

. - 23 preform to contract longitudinally without tearing.

This is also facilitated by the guiding of the teeth 250 as previously discussed.

As the pre-form is shaped, the end panels 234, 236 5 of the forming block 210 retract to accommodate the pre-

forms new dimensions.

The shaped teeth 250 are moved out of engagement with the surface of the pre-form after shaping is completed under the action of springs 250.

10 Once shaping is completed, the drive shaft rotates clockwise towards the top dead centre position, through a stripping position as shown in Figure 26D.

During this movement, the forming arm 200 moves upwardly and the ejecting tray 300 moves back towards 15 the chute 302. When the forming arm 200 reaches the stripping position shown in Figure 24D, the bottom of the folds 44 of the pre-form held on the forming block 210 are engaged by the spring mounted arms 222. The arms 222 retain the pre-form as the forming arm 200 20 continues to move upwardly, causing the pre-form to drop onto the ejecting tray 300 as it moves across towards chute 302.

The infeed means 90 does not move significantly up to the stripping position shown in Figure 26D.

25 As the drive shaft continues to rotate towards its original position, the forming arm moves the forming block 210 up above the level of the infeed means 90, the infeed means 90 moves to the first position for presenting a new pre-form to the forming block, and the 30 ejecting tray 300 ejects the shaped pre-form in to the chute 302 and hence onto the conveyor 94 for onward movement towards the compression station 74.

This cycle is then repeated.

The shaped pre-form continues to the end of 35 conveyor 94 through gate 400 which is in the open position. On reaching the end of conveyor 94, the pre form engages the end stop 95. At this point, the

- 24 carriage 422 sides on rail 420 bring the plunger 96 into contact with the end face 8 of the pre-form and pushing it into the compression chamber 98. The end gate 406 of the compression chamber is in the raised position.

5 Plunger 96 continues moving into the compression chamber, with the carriage 422 riding in the groove 418, thereby concertinaing the shaped preform to more firmly define its folds.

On reaching the blind end of the groove 418, the 10 sensor 410 sends a signal to cause the end stop 408 to retract allowing the gate 406 to fall, and for infeed gate 400 to open allowing the next shaped pre-from to move into the compression station 74. The shaped and finished pre-form ejects itself from the compression 15 chamber as the folds 44 expand, and falls into the collection basket 102. The gate 406 is then closed once more. The finished pre-form may then be processed as desired to convert it into a finished carton. For 20 example, a lid could be added to retain the pre-shaped pre-form in its contracted condition.

Operation of the apparatus to provide a shaped pre-

form in accordance with the second embodiment of the invention, as shown in Figures 5-7, is identical to that 25 described in respect of the first, although with suitable modifications to the forming block. However, the pre-form of Figure 7 does not undergo the compression step, and instead proceeds directly from conveyor 94 to a further location in which an end cap is 30 attached to the shaped pre-form to help retain its shape. The resulting carton may be used as it is, or combined with e.g. a lid to form a box depending upon the characteristic desired of the final carton.

Claims (1)

1. as Claims:

   5 1. A method for producing a shaped carton or part therefor, the method comprising: providing a blank; erecting the blank to produce a pre-form; and forming said pre-form to bring it closer to a final shape.

   10 2. The method of claim 1, wherein the blank includes means to facilitate its erection into a pre-form.

   3. The method of claim 1 or 2, further comprising storing the blank in a storage location and delivering 15 the blank from the storage station to an erection station for erection into said pre-form.

   4. The method of any preceding claim wherein the step of erecting the preform comprises transforming the 20 blank from a 2-dimensional form to a 3dimensional form.

   5. The method of any preceding claim further comprising supplying the preforms to a forming station in a stepwise manner.

   6. The method of any preceding claim wherein forming the pre-form to bring it closer to said final shape comprises folding the pre-form.

   30 7. The method of claim 6 further comprising providing the pre-form with crease lines to facilitate its folding. 8. The method of claim 7, wherein the fold lines are 35 arranged such that the pre-form can be folded into a corrugated configuration.

   - 2 9. The method of any preceding claim further comprising using a form to bring the pre-form closer to said final shape.

   5 lo. The method of claim 9, wherein the step of forming the pre-form comprises using shaping means to urge the pre-form into engagement with the form thereby deforming the pre-form.

   10 11. The method of claim 10 further comprising deforming the pre-form starting in a middle region of the form and working outwardly therefrom in both directions.

   12. The method of any of claims 9 to 11, further 15 comprising stripping the formed pre-form from the form after said deformation.

   13. The method of any preceding claim further comprising the step of finishing the pre-form to help to 20 maintain the shape imparted to it in the forming stage.

   14. The method of claim 13 wherein the finishing step comprises joining the shaped pre-form to one or more additional parts.

   15. The method of claim 13 or 14 wherein the finishing step comprises compressing at least a part of the shaped pre-form. 30 16. A method of forming a concertina-like body from cardboard, paperboard, plastics or other foldable sheet material comprising folding the sheet material to form a series of corrugations therein and then compressing the folded material in a direction perpendicular to the 35 corrugations to collapse the corrugations.

   17. The method of claim 15 or 16 further comprising

   - 1 confining the pre-form as compression is carried out so as to limit its movement in directions other than the direction of compression, 5 18. An apparatus for producing a shaped carton or part therefor, the apparatus comprising: means for supplying a blank; means for erecting the blank to produce a pre-

   form; and means for forming the pre-form to bring it closer to a final shape.

   19. The apparatus of claim 18, wherein the blank includes means to facilitate its erection into a pre-

   form. 15 20. The apparatus of claim 18 or 19, further comprising a storage location for storing the blank and an erection station for erecting the pre-form.

   21. The apparatus of any of claims 18-20, further 20 comprising means for transferring the pre-form from the erection station to a forming station.

   22. The apparatus of any of claims 18 to 21, further comprising transfer means for supplying the pre-forms to 25 a forming station at a desired rate.

   23. The apparatus of claim 22 wherein said transfer means comprises a reciprocating transfer mechanism for supplying pre-forms to the forming station in a stepwise 30 manner.

   24. The apparatus of claim 22 or 23 wherein the transfer means comprises a reciprocating gripper mechanism which grips a pre-form at a first position and 35 moves to a second position where it releases the pre-

   form and returns to its first position to grip a second pre-form.

   - a-, 25. The apparatus of any of claims 18 to 24 wherein the pre-form is provided with crease lines to facilitate its folding. 5 26. The apparatus of claim 25 wherein the fold lines are arranged such that the pre-form can be folded into a corrugated configuration.

   27. The apparatus of any of claims 18 to 26 wherein lo maid means for forming the pre-form comprises a form.

   28. The apparatus of claim 27 wherein the form comprises a forming block having a corrugated forming surface. 29. The apparatus of claim 27 or 28 further comprising shaping means for urging the pre-form into engagement with the form.

   20 30. The apparatus of claim 29 wherein the shaping means is movable by drive means towards the form.

   31. The apparatus of claim 30 wherein the shaping means comprises shaping members arranged for progressively 25 moving towards the form.

   32. The apparatus of claim 31 wherein said movement starts in a middle region of the form and works outwardly therefrom in both directions.

   33. The apparatus of claim 31 or 32 wherein the shaping members are moved in an appropriate sequence by cam means associated with respective shaping members.

   35 34. The apparatus of any of claims 30 to 33 wherein guide means is provided for guiding the shaping members towards the form.

   ot- 35. The apparatus of any of claims 31 to 34 wherein the shaping members are provided with respective pins which ride within grooves as the shaping members move towards the form.

   36. The apparatus of any of claims 31 to 35 wherein the shaping members are configured to move inwardly towards the form and laterally in the direction of shortening of the pre-form.

   37. The apparatus of any of claims 27 to 36 wherein the form is movable from a position for receiving a pre-form to a forming position.

   15 38. The apparatus of claim 37 wherein the form is linearly movable.

   39. The apparatus of claims 37 to 38 wherein the forming block is provided with means for retaining the 20 pre-form as it is moved into the forming position.

   40. The apparatus of any of claims 37 to 39 further comprising means for stripping the shaped pre-form from the form as the form returns towards the receiving 25 position.

   41. The apparatus of claim 40 wherein the stripping means comprise means which deflect to allow passage of the pre-form retained on the form in a first direction 30 but not in an opposite direction.

   42. The apparatus of any of claims 27 to 41 wherein the forming station further comprises ejection means for ejecting the shaped pre-form from the forming station.

   43. The apparatus of claim 42 wherein the ejection means is arranged to receive a shaped pre-form as it is

   - 3D released from the form.

   44. The apparatus of claim 42 or 43 wherein the ejection means is arranged to feed the shaped pre-forms 5 to outfeed means.

   45. The apparatus of any of claims 42 to 44 wherein the ejection means comprises a reciprocating table.

   lo 46. The apparatus of claim 45 wherein the table is arranged above the forming station and is moved in synchronization with the form for catching shaped pre-

   form as it is released from the form and carrying it to out feed means.

   47. The apparatus of any of claims 27 to 46 further comprising means for compressing at least a part of the shaped pre-form.

   20 48. The apparatus of claim 47 further comprising means for confining the pre-form as the compression is carried out so as to limit its movement in directions other than the direction of compression.

   25 49. The apparatus of claim 48 wherein the pre-form is pushed into a compression chamber using a compression member. 50. The apparatus of any of claims 47 or 49 wherein the 30 compression station comprises means for releasing the formed pre-form when it has been compressed to a predetermined extent.

   51. The apparatus of claim 50 wherein the end wall of 35 the compression chamber comprises a gate through which the compressed pre-form is ejected.

   _ 31 52. The method or apparatus of any preceding claim wherein the preform is a tray.