AU619248B2 - A method of and an apparatus for isolating flat parts - Google Patents

Description

I

FORM 10 6?1 21SPOSON FERGUSON COMMONWEALTH OF AUSTRALIA PATENTS ACT 1952 COMPLETE SPECIFICATION

(ORIGINAL)

FOR OFFICE USE: Class Int. Class Complete Specification Lodged: Accepted: Published: Priority: Related Art: oooooo o 0 0 0 o 0 o oooo o QQ 0 0 0 0 0 0 o 0 00 o o o o 000 o aa 0 aC 6 6 t Name of Applicant: Address of Applicant: Address for Service: Tetra Pak Finance Trading S.A.

70, Ave. Ramuz CH-1009 Pully

SWITZERLAND

Spruson Ferguson, Patent Attorneys, Level 33 St Martins Tower, 31 Market Street, Sydney, New South Wales, 2000, Australia ti 06 1

O

4 0 Complete Specification for the invention entitled: A Method of and an Apparatus for Isolating Flat P arts The following statement is a full description of this invention, including the best method of performing it known to me/us L _-L-LZI Abstract A method of and an apparatus for isolating flat parts The invention describes a method of singling-out or separating paper blanks for the manufacture of packings, and in which the flat parts are superposed in a stack So that singling-out takes place reliably even with automated feeding of the stack it is according to the invention proposed that the stack of paper blanks lying substantially horizontally, be supported at oppositely disposed edges (21, 22) and that the bottom blank be pushed on one side horizontally and sufficiently beyonu the first support on one side to lose support and to hang down in freely supported manner after which it is then also pushed in the opposite direction by the first support and dropped down.

o 0 0 o 0 0 00 0 0 oo 0 0 e 00 SBR:KRS133P A method of and an apparatus for isolating flat parts The invention relates to a method of and also to an apparatus for isolating or singling-out flat parts, particularly blanks consisting of paper, cardboard or the like for the manufacture of packagings, and in which the flat parts are superposed in a stack.

Although the invention generally relates to the separation of one to five, eg three flat parts and to the singling-out of the flat parts, the invention hereinafter will for better understanding and for ease of illustration, be described with reference to blanks which consist of paper, 1cardboard or such like and which are intended for the manufacture of liquids packagings.

It is known to produce liquids packagings from a carrier material, eg paper, cardboard or such like, coated on both sides with a synthetic plastics material. Where these packings are concerned, a longitudinal sealing seam is used to form a sleeve from a flat blank and, while the sleeve is lying flat so that as far as this state it may also be regarded as a "blank", it is fed to a forming station where the sleeve is folded up into its final condition and fed to a machine having at least one shaping wheel in which on the one hand a lid of synthetic plastics or carrier material is injection moulded into position, the packing which is thus closed at one end is filled and afterwards the packing is sealed at the opposite end by folding, after which the filled packing is carried away and Spacked in an outer container.

Various folding devices and magazines have been proposed for such packing producing machines. For example, it has already been suggested to produce the packings from a continuous web in that the paper web unwound from a roll is separated, blank for blank, the blanks then being shaped into sleeves, folded up and then fed to the mandrel of the shaping wheel.

Since disposable packings for liquids, e.g. milk, juices, and S consisting of paper are enjoying increasing popularity in the market so that ever increasing quantities of this type of packing are being offered in the market place, manufacturing machines must be provided which can offer relatively high output levels. In this respect, it has been demonstrated to be advantageous for the paper sleeves to be grouped together in a stack in one magazine and fed to the packing producing machine in stack form.

If, then, blanks (eg in the form of flat sleeves) are supplied SBR:KRS133P -3stackwise to a packing machine, then singling-out may be problematical.

It is well known that paper is a yielding material, even when it is coated with synthetic plastics material. If, then, the blanks are stacked on top of one another and are stored for several months before being handled in the packing machine, i.e. before being singled-out and folded up, then it has been shown that the individual flat parts the blanks) stick to one another and their reciprocal adhesive friction makes singling-out considerably more difficult.

Therefore, the invention is based on the problem of providing a method of and an apparatus for singling-out flat parts, by means of which such flat parts, particularly paper blanks, can be reliably detached from a stack even when the stack feed is automated.

According to the invention, this problem is for the method resolved in that the stack of flat parts rests substantially horizontally and is supported at oppositely disposed edges, the very bottom part being 0 displaced on one side horizontally and sufficiently beyond the first o o S00 support on one side for it to lose its support so that it is hanging down in freely supported manner after which it is then also pushed away in the o opposite direction by the first support and drops down. In contrast to prior art singling-out methods, in which flat parts travel tickets) S are pulled from the bottom of the stack by friction belts or friction rollers, the invention envisages a pushing or sliding movement by which the edge of the flat part is engaged without any action of force (friction) but so to speak in form-locking fashion via an abutment, and is then displaced 0 substantially horizontally. This displacement very reliably ensures movement of the flat part which then no longer remains clinging to the underside of a stack if the adhesive friction due to prolonged storage is for example greater than the friction force between the underside of the flat part and the top of the friction belt. In this way, flat parts can be reliably isolated from a stack.

If, now, the height of the stack of flat parts is quite considerable GO so that for example a large number of parts are accommodated in one magazine which is then kept in store, it can happen that the weight of the parts which rest on the bottommost flat part gives rise to such a considerable adhesive friction that it is no longer reliably guaranteed that only one single part one single paper blank) is gripped and loosened during the horizontal pushing movement. Instead, two or even three flat parts may well be sticking to one another and be jointly gripped and pushed aside so that they are all separated from the stack.

SBR:KRS133P -4- Also this problem can according to the invention be resolved if in the case of an advantageous further development of the method, the flat parts separated from a first, e.g. upper stack are then fed to a downstream second stack, e.g. underneath, and are then isolated from this latter. In the first or upper stack or during the said separation process, there is so to speak a preliminary singling-out, although the word "singling-out" may be inappropriate if in the disadvantageous manner described hereinabove; the weight of the very high stack cannot prevent two, three or even four flat parts clinging rigidly to one another and being jointly separated from the stack. This problem is overcome by the method according to the invention, as a result of this so-called preliminary singling-out or separation in the first or so-called upper station. The weight of the flat parts or of the stack plays a considerable part both in the case of the method and also in the case of the apparatus according to the invention, which is why we speak of "top and "bottom". At the same time, there is no need for the disposition of one stack above the other or of one processing 4 0 Oo station above the other to be exactly in a vertical direction (plumb).

With any disposition "above one another" within the meaning of the invention, however, there is a substantial vertical component. Even with an inclined stack of flat parts, one can still properly speak of top and S bottom.

By the preliminary singling-out or separation of the flat parts from the upper stack, therefore, a loosening of the flat parts from one another and thus an overcoming or cancellation of the adhesive friction between adjacent parts is achieved. This process will advantageously be sufficient ,00" for the majority of steps in the procedure so that the flat parts in the second downstream or bottom stack can be reliably pushed out singly from their support. Furthermore, with this two-stage method and with this embodiment of the invention, there is the further advantage that the bottom stack can preferably be allowed to grow just to a height of 20 to 30 flat parts, in other words allowing a separation of further parts from the first S, top stack only when the bottom stack is no higher than the desired maximum height.

According to the invention, it is furthermore advantageous if at least two superposed stacks of flat parts, lying substantially horizontal, are supported at opposite edges, that at least one bottommost part of the upper stack is pushed on one side horizontally and sufficiently beyond the first support on one side that it loses the support and is hanging down in freely supported fashion whereupon it can also be pushed in the opposite SBR:KRS133P direction by the first support and fall down onto the bottom stack from which in the same way the bottommost part is detached.

Whereas previously the two-stage method of singling-out articles according to the invention can also be carried out with other equipment, it is hereinabove described as being preferable to use the pushing or sliding movement described at the outset, wherein the edge of a flat part for example abuts a pusher and is in this way pushed back and forth horizontally in order to be detached from the stack. By the combination of both measures, namely the reciprocating pushing via the form-locking abutment on the one hand and the two-stage separation of the flat parts on the other, the problem posed at the beginning is resolved in a particularly satisfactory manner, the problem being namely that of reliably singling-out flat parts even when they are supplied in the form of very high and very heavy stacks so that the great weight means that the bottom flat parts, if they consist of deformable material, are held by considerable adhesive friction.

SoAccording to the invention, it is also expedient if the height of the S stack of the parts to be singled-out is sensed and when it reaches a S minimum height a further stack is supplied. This measure serves to promote rationalisation in the production of packings if, namely, machines are built in which only stacks of blanks are adjusted and completed packings are discharged after being filled. In fact with rationalised automatic machinery, a considerable stack height is desirable, because then the loading times are shortened.

This sensing of the stack height can take place in various per se known ways. With the single-stage method according to the invention, after one stack has been consumed, a new and complete stack can likewise be supplied, as with the two-stage method in which the supply of a complete new stack takes place of course into the top position. In this respect, it will be appreciated that the sensor for the stack height transmits a signal S to a control means which undertakes the supply of the further new stack.

According to the invention, it has furthermore been found to be advantageous if the stack of flat parts is moved on a substantially horizontal path for separation and/or singling-out in a position which is inclined in respect of the vertical. After discharging the stacks of flat parts, for example into the magazine of a buffer feeder means, it has been found to be ideal to achieve a loosening up of the flat parts from one another within a stack in that the stack is caused to change shape as it is inclined to the vertical. It may be particularly expedient for the stack SBR:KRS133P -6to be tilted in two directions out of the vertical, directions which are substantially at a right angle to each other. The adhesive friction between the individual parts within the stack is most easily overcome in this way. By way of illustration, there will now follow a description of an example in which the upper flat parts of a stack are displaced by the tilting described here, viewed in the direction of movement of the feeder means, for instance through 150 in respect of the direction of movement and through a similarly great or different angle in the plane at right angles to the direction of movement. If in a stack, from the bottom upwards, whichever happens to be the upper part is displaced in the direction of feed rearwardly and also to one side, then the described tilting action is achieved, the stack then geometrically assuming the form of a parallelepiped in the shape of a prism, the basic surfaces of which are parallelograms. Therefore, if the stack is standing exactly in the vertical, then it can be geometrically described as a block and if it is tilted within the meaning of the invention, then it assumes the form of a S prism with parallelograms as its basic surfaces.

*The invention also describes an apparatus for singling-out flat a parts, particularly blanks consisting of paper, cardboard or the like, and intended for the manufacture of packings, and in which the flat parts are superposed in a stack. Where the apparatus is concerned, the problem according to the invention is resolved in that at the bottom end of any two housing walls spaced apart by the same amount as the width of the flat parts, there is a supporting projection above which each housing wall S comprises a gap to accommodate in each case a substantially horizontally movably driven ejector and in that between the supporting projections which are situated opposite each other in pairs there is a free space. Where the manufacture of liquids packings is concerned, one can imagine the block-shaped packing, and in the case of the currently available milk Kpackings, the packing will have its longitudinal direction extending in the vertical. Prior to filling and straightening up the relevant packing S blank, however, its longitudinal axis is thereby established and also the longitudinal sealing seam of the sleeve is disposed parrallel therewith, the said sleeve likewise being understood as being a flat part within the meaning of the invention. The longitudinal axis of the sleeve is also understood as being the length of the sleeve or of the blank or of the flat part and consequently the width of the flat part is that which is measured transversely thereto. In the case of the apparatus according to the invention, the housing walls are spaced apart by a distance corresponding SBR:KRS133P

A

to the width of the flat parts which are to be detached and they have short or with other embodiments also relatively long gaps in the vicinity of the supporting projections. Through the gaps can be pushed correspondingly small ejectors, substantially in a plane at right angles to the housing walls and in particular parrallel with the plane formed by two oppositely disposed supporting projections of one pair and which is substantially horizontal. It will be appreciated that with such a construction an ejector is able to push a flat part which is to be detached from one supporting projection down and into the oppositely disposed gap so that the part, once it has left the supporting projection, loses its support and hangs down in freely supported manner, being clamped only by the oppositely disposed gap.

Advantageously, the invention is further developed in that two pairs of oppositely disposed supporting projections are disposed above each other being spaced apart by the distance of a stack of parts, together with whichever happens to be the adjacently disposed pair of oppositely disposed o 0 S ejectors. While hereinabove the measures of developing the sliding or o 00 pushing device are described as having the gaps alongside the supporting projections, the superposition of two pairs of projections makes it in turn possible to carry out the two-stage version of the method according to the invention whereby in the first generally upper station the separation of at least one flat part takes place, while in the second and bottom station separation of only one single part takes place, but from the underside of the relevant stack. Consequently, the upper stack may comprise up to 300 0000 S blanks all situated one above another, and the upper pair of supporting projections may comprise adjacently disposed ejectors which are larger and/or coarser. In fact, where the separation of flat parts in the first S, procedural step from the upper stack is concerned, it is not so important whether a single flat part or two or even up to four parts is or are simultaneously separated from the upper stack. Where this "preliminary 00 04 S singling-out" is concerned, it is for practical purposes just a preliminary ,0 *o stage in which the flat parts are loosened up from one another to cancel out the adhesive friction. On the other hand, there ought not to be more than 30 blanks superposed one on another in the singling-out station which is underneath, in order not to create a weight which in turn excessively increases adhesive friction which impedes singling-out. Therefore, also the gaps disposed alongside the bottom supporting projections are made of smaller height and the corresponding ejectors are smaller and finer. The bottom ejectors therefore grip only one single flat part at its edge, SBR:KRS133P -8certainly not gripping two parts at the same time.

According to the invention, it is also expedient if there is at a distance from the pair of oppositely disposed supporting blanks a photoelectric cell which is connected via a control means electrically to the motor of a stack feeder means having substantially horizontally movable transport magazines.This control and reationalising of the overall machine or also of the singling-out of flat parts of any other type is successful both with a single station having only one stack of flat parts and only one pair of supporting projections but can be equally well used with two superposed stations or stacks. In this case, the photoelectric cell is so disposed that the previously described heights of stacks are nut exceeded, ie the height of 30 parts in the bottom stack. On the other hand, this or some other photoelectric cell may also ensure that as the foremost stack is used up, feeding of the next stack is guaranteed.

Furthermore, according to the invention and in the case of another embodiment the stack feeding means may comprise a pair of flat link chains rotatable about shafts, the shafts being inclined by preferably 100 to 0 0 in respect of the vertical in a first direction, a row of pusher rods being mounted by equally long support arms on the flat link chains, the ea pusher rods being inclined in respect of the vertical plane at right angles to the first direction of inclination of the shafts plus a further 100 to 200. Mention has already been made hereinabove of the prismatic shape with a parallelogram base surface for the formation of the particular stack. By the aforementioned measures of the inclined flat link chains on the one hand and the pusher rods on the other, the stacks can be moved in S just this form on the otherwise substantially horizontally extending conveyer path.

The use of the singling-out device is particularly versatile if according to the invention there is under the bottommost pair of oppositely disposed supporting projections, spaced apart therefrom, a fixed basket shaped like part of a cylindrical shell, to accommodate the very bottom part which has been detached from the stack. In fact, it is then possible by means of a distributor in the case of a paper sleeve always to be moving one sleeve to one side into a folding station and shortly afterwards, during the return movement of the distributor, to move the next detached sleeve in the other direction into a second folding station; a movement which like the swinging of the distributor, brings about movement of detached sleeves into two stations one shortly after the other.

Further advantages, features and possible applications of the present invention will emerge from the ensuing description of preferred examples SBR:KRS133P 9of embodiment in conjunction with the accompanying drawings, in which: Fig. 1 is a perspective view of the diagram of the overall device for automatic feeding to a front top stack, separation of sleeve-like blanks therefrom, to be passed to a bottom stack, and onwards conveyance of the sleeves detached from the bottom stack, by means of a distributor not shown, arcurately to one and shortly afterwards to the other oppositely disposed folding station of a packing producing machine, Fig. 2 is a view of the stack feeding means with flat link chain and driving motor viewed along the line II-II in Fig. 3, Fig. 3 is a plan view of the stack feeding means looking from the top downwards in Fig. 2 and Figs. 4 to 6 diagrammatically show the singling-out device in the direction of feed of blanks in various positions during separation or singling-out.

Fig. 1 diagramatically shows in the overall view on the left the stack feeding means generally designated 1 and also shown in Figs. 2 and 3 in two different views but not designated in those illustrations by the reference numeral 1; and in the direction of feed (arrow 2) of the stacks 3, 3' of blanks 4 in Fig. 1 there is the singling-out or separating station on the right, with the diagrammatically shown bottom detached blank 4 and, shown in broken lines, its arcuate path 5 to the folding station in which the blank 4 (flat part) is shown as opened up into the sleeve shape.

It is intended firstly to explain the stack feeding means 1. Fig. 1 shows the three adjacently disposed parrallel support rails 6, of which only two are shown in Figs. 2 and 3. In this way, a substantially horizontal plane is established which is actually shown as lying in the horizontal, while at right angles to this imaginary plane, the top of the support rails 6, on which the stacks 3 are pushed in the direction 2, are disposed the shafts 7 of the pair of flat link chains 8, 8' which, as seen t C 0 in the direction shown in Fig. 1, are inclined rearwardly in 15 In other words, the shafts 7 are inclined rearwardly in a plane out of the vertical at the top, in the region of the upper flat link chain 8, and in respect of the bottom flat link chain 8' which lies at right angles to the actual horizontal plane and also at right angles to the direction of feed 2. Thus, also, the imaginary plane connecting the two strands of the chains 8, 8' in the direction of view in Fig. 1 are inclined rearwardly at the top. On account of the small amount of inclination, it is not readily visible to the naked eye in respect of the stacks 3. Connecting links 9 SBR:KRS133P connect push rods 10 to flat link chains 8, 8' which apart from the manner described above have their top ends 11 inclined rearwardly not only in the direction of view of Fig. 1 but also inclined to the left. This second leftwards inclination therefore means the enclosing of an angle of about between the longitudinal axis of the particular push rod 10 with a vertical which is at right angles to the direction of feed 2. In this way, the stacks 3 take the form of prisms which base surfaces resembling parallelograms, because when they are flat the sleeves 4 are rectangular.

Broken lines show the longitudinal sealing seam 12 of the relevant sleeve 4.

Not shown in Fig. 1 but visible in Figs. 2 and 3 are the spine support rods 13 which are likewise mounted on the flat link chains 8 and 8' and of which the top ends, in the direction of view, are inclined rearwardly by 150 in the paper plane. The bottom right hand part of Fig.

3 shows the two L-shaped planes passing through the spine support rods 13 and the push rod 10 which constitute the magazine for the relevant stack 00 3. Fig. 2 shows a view in opposition to the direction of feed 2 showing a 00 stack 3 of blanks 4 which lie on the right against the spine support rods 13 while on the left they are guided by a low guide plate 14. Fig. 3 shows S* the stack feeding device empty, with no stack. The left-hand one of the shafts 7 (in Fig. 3) is the drive shaft by which the sprockets 15, 15' are driven by means of the geared motor 16. It will be understood that with a corresponding control of the geared motor 16, the individual stacks 3 of 0000 blanks 4 (flat parts, sleeves) can be intermittently transported in the S direction of feed 2 forwards by the length of a stack 3.

0 Singling-out or separating station o In Fig. 1, "forwards" is shown on the right hand side in the direction of feed 2, ie the push rod identified by reference numeral 10 on the right moves along the right hand sprocket in a semi-circle out of the path in the direction of feed 2 so that the right hand stack 3, in Fig. 1 the third stack from the left, can be pushed by the support rail 6 down into the housing of the singling-out station and forwards, the singling-out station being shown in detail in Figs. 4 to 6. The front stack is thereby moved towards the front support rail 17 by the push rod 10 moving out of the conveyer path 2, the front support rail 17 not being shown in Figs. 4 to 6 but being shown as stationary in Fig. 1. Between the first "top" stack 3 of blanks 4 and the second "bottom" stack 3' of blanks there is a free space 18 which is shown in the right proportion to the stacks in Figs.

4 to 6 while Fig. 1 shows it only diagrammatically as a small step. The view in Figs. 4 to 6 must be regarded as in the direction of feed indicated SBR:KRSI33P -IIp- ll-.l by the arrow 2. The left hand housing wall 19 is longer than the right hand housing wall 20 because also the wall 19 must be imagined as being inclined to the left at the top by 150 in respect of the vertical line located in the paper plane in Figs. 4 to 6. In the diagrammatic view in Figs. 4 to 6, the individual blanks 4 are disposed exactly parallel alongside one another and substantially at a right angle to the two housing walls 19, 20. In fact, however, there may be a small gap on the left on the right wall 20 between the wall 20 and the stack 3, the gap being wedge-shaped, because in particular the upper stack 3 is disposed in a position in which it is inclined in two directions.

Whichever is the right hand edge of a blank 4 is designated 21 while the respective left hand edge is designated 22. Whichever happens to be the bottom blank in the stack 3,3' rests on supporting projections 23, 23' for the upper stack 3, 3' rests on supporting projections 23, 23' for the 0 I0 0 upper stack 3 and 24 to 24' for the bottom stack The housing walls 000 20 are spaced apart from each other by the distance of the width B in contrast to the length L. Beside the upper supporting projections 23, 23' there is in each case a gap 25, 25' while alongside the bottom supporting projections 24, 24' there is in each case a gap 26, 26'. Correspondingly e high ejectors 27, 27' are so disposed that they can slide through the gaps 25' in the direction indicated by the horizontal double-headed arrow 28. These ejectors 27, 27' are coarser and thicker than the ejectors 29, 29' which are likewise movable and which are disposed alongside the bottom S supporting projections 24, 24'. Each ejector 27, 27', 29, 29' is adapted for movement via bearing plates 30 in the direction of the double-headed S arrow 28 exactly parallel through the appropriate gap. The drive is shown S diagrammatically in Fig. 6, in that a plate 30' is extended on each side in other words two plates both of which are connected by a rod 31 being adapted to be moved in the direction of the double-headed arrow 28 via the piston rod 32 of an air cylinder 33. As this happens, the plates rotate about pivot points 34.

At a distance from each pair of oppositely disposed supporting projections 23, 23' and 24, 24' in the view shown in Figs. 4 to 6, between these two pairs of supporting projections there is a photoelectric cell with receiver 36 which is electrically connected to the geared motor 16 of the stack feeding means 1 via a control means not shown.

In operation, the singling-out device according to the invention operates in such a way that Fig. 4 can be taken as the starting point for the description. There is both a bottom stack 3' of blanks 4 and also, at SBR:KRSI33P -12a distance therefrom, a top stack 3, supported at the edges 22, 21 of the relevant bottom sleeve 4 on the supporting projections 24,24' for the bottom stack 3' and 23, 23' for the top stack 3. It is assumed that according to Fig. 4 the bottom stack 3' has a height of 30 blanks 4. The ejectors 29, 29' are coupled to one another. They start to perform about the pivot point 34 a movement in the direction of the arrow 28 leftwards, so that the right hand edge 21 of the bottom blank 4 is gripped and pushed free leftwards from the right hand supporting projection 24'. As this happens, the left hand edge 22 of the blank 4 moves into the gap 26 which is cleared by withdrawal of the left hand ejector 29. This displacement in the direction of the arrow 28, leftwards, takes place in the direction of one side, namely the left hand side, until the blank 4 has lost the support of the right hand supporting projection 24' and is now, as shown in Fig. hanging down in a freely supported manner while on the left hand side it is held clamped on the left hand side in the gap 26.

Now the direction of movement of the ejectors 29, 29' is reversed so that it is to the right in the direction of the double-headed arrow 28, rightwards away from the first support or left hand supporting projection 24, so that the situation in Fig. 6 is established and the blank 4 is detached. This interplay continues between the positions in Figs. 4, 5 and 6 until the bottom stack 3' consists for instance of just three to four blanks. The photoelectric cell 35 shown only diagrammatically in Figs. 4 to 6 senses this situation in respect of the bottom stack 3' and gives a S signal to the control of the upper ejectors 27, 27' which now work to fill the bottom stack 3' in the same way as has just been described in connection with the ejectors 29, 29', until the bottom stack 3' has again reached its maximum height of about 30 blanks 4.

The difference between the activity and the action of the upper ejectors 27, 27' at the bottom end of the top stack 3 in respect of the bottom singling-out station of the stack 3' lies in that, as also shown diagrammatically in Figs. 4 to 6, the ejectors are of thicker and coarser construction and possible separate two or even four blanks 4 from the top stack 3 simultaneously.

Fig. 5 illustrates this situation with the example of two blanks 4.

Fig. 5 shows in the upper portion how the right hand ejector 27' has just filled the right hand top gap 24', pushing two blanks 4 simultaneously into the top left hand gap 25, because this of course is opened up by the withdrawal of the ejector 27. Now the two blanks 4 are hanging down in freely supported manner, being retained clamped only on the left hand side SBR:KRS133P -13i by the supporting projection 23 or the gap 25 disposed alongside it. If, then, in the transition to the condition in Fig. 6, the left hand ejector 27 is pushed forwards and rightwards through the gap 25 in the direction of the doubleheaded arrow 28, the last support of the two bottom blanks 4 is removed and they fall freely through the space 18 and down onto the bottom stack This action can be repeated until the photoelectric cell adjusts the displacement drive of the upper ejectors 27, 27' because the height of the bottom stack 3' has been reached.

If, then, the top stack 3 is emptied down to about two or five blanks, then a further photoelectric cell, not shown, senses this situation and gives a signal to a control means which switches on the geared motor 16 which then moves the push rods 10 forwards and to the right by the length of a stack magazine 36 and in the direction of the arrow 2 in Fig. 1. This new stack then drops down onto the top stack 3 of Fig. 4 so that the 00" feeding and topping up process is completed.

0o o° oFurther nrocessing and transport of the separated bottom sleeve 4 0 according to Fig. 1 then takes place lengthwise of the path 5 shown by 0.0o broken lines, into a folding station where according to Fig. 1, top right, the sleeve is shown diagrammatically in the folded state.

0 0 o000 Six sheets of drawings 0 0 000 0 o 0, 0 0 0 0 0 09 o 1 4 03 0 0o SBR:KRS133P -14-

Claims (9)

1. Apparatus comprising: a pair of opposed walls adapted for location therebetween of a plurality of flat blanks of paper, cardboard or like material for the manufacture of packaging; first means adapted to support a first, lower stack of said blanks with the lowermost of said blanks in said first stack being disposed substantially horizontally between respective bases of said opposed walls; second means adapted to support a second, higher stack of said blanks at a location between said opposed walls above and removed from the uppermost blank in said first stack of blanks; first ejector means adapted firstly to force said lowermost blank in said first stack of blanks in a first direction away from its contact with said first support means and one of said walls so that said lowermost blank is thereafter supported by said first support means in :o:o:contact only with the other of said walls, said ejector means being further adapted secondly to force said lowermost blank out of contact with said other of said walls so that said lowermost blank is free to fall from said first stack; and o 0 i second ejector means adapted in respect of said second stack of blanks to remove blanks from the bottom of said second stack of blanks to replenish the first stack of blanks as the lowermost and successive blanks in said first set of blanks fall therefrom.

2. Apparatus as defined in claim 1 wherein said second ejector aa means is adapted firstly to force the lowermost blank in said second 0 stack of blanks in a first direction away from its contact with said second support means and one of said walls so that said lowermost blank of said second stack is thereafter supported by said second support means in contact only with the other of said walls, said second ejector means being further adapted secondly to force said lowermost blank of said second stack out of contact with said other of said walls so that said lowermost blank of said second stack thereby is able to fall to a location on top of said first stack of blanks to at least partially replenish said first stack.

3. Apparatus as defined in claim 2 wherein said second ejector means is adapted to simultaneously remove from said second stack said lowermost blank of said second stack together with one or more of the blanks of said second disposed adjacent said lowermost sheet. -15 (C-o ao RL/4p. ~bpla RLF/1453h 6'7 SBR:KPS133P

4. Apparatus as defined in any one of claims 1 to 3 further comprising a photoelectric cell means adapted to determine when a sufficient number of blanks have been removed from said first stack and to activate said second ejector means to thereby replenish said first stack. Apparatus as defined In any one of the preceding claims further comprising conveyor means adapted to support thereon a plurality of further stacks of blanks and to transport to a location in replacement of said second stack of blanks one of said further stacks of blanks to replace said second stack of blanks when the blanks of said second stack have all been used to replenish said first stack of blanks.

6. Apparatus as defined in claim 5 further comprising a second photoelectric cell means adapted to discern when said second stack requires replacement and to activate said conveyor to transport a said further stack of blanks to a location in replacement of said second stack of blanks.

7. Apparatus as defined in claim 5 or claim 6 wherein said conveyor means comprises a plurality of support rails on which said further stacks of blanks are disposed with the plane of blanks inclined to the horizontal.

8. Apparatus as defined in claim 7 wherein the plane of said blanks is inclined at about 150 to the horizontal. S9. Apparatus as defined in claim 7 or claim 8 further comprising a plurality of spine support rods against which said stacks of blanks may rest, said support rods being disposed vertically relative to the plane Sof the surfaces of said support rails. A method of isolating flat blanks of paper, cardboard or like material from a stack of said blanks, said method comprising the steps of: providing a pair of opposed walls; locating and supporting between said pair of opposed walls a first and a second stack of said blanks, said first stack being disposed lower than said second stack and supported therefrom; firstly forcing the lowermost blank in said first stack of blanks in a first direction away from its support with one of said opposed walls so that said lowermost blank is thereafter supported only in contact with the other of said walls; secondly forcing said lowermost blank out of its support with the /0 other of said walls so that said lowermost blank is free to fall from -16-RLF/1453h RLF/1453h r*rlu-ir*~*-~E mmrrr;ir;~ i ;1 r I said first stack; and removing blanks from the bottom of said second stack of blanks to replenish the first stack of blanks as the lowermost and successive blanks in said first set of blanks fall therefrom.

11. Apparatus substantially as described herein with reference to the accompanying drawings.

12. A method of isolating blanks substantially as described herein with reference to the accompanying drawings. DATED this EIGHTEENTH day of SEPTEMBER 1991 Tetra Pak Finance Trading S.A. 00 Patent Attorneys for the Applicant :SPRUSON FERGUSON 0 0o 0 o -17- RLF/1453h 0 0 4^\ t o ^s:oRL/o53 o