GB2079260A

GB2079260A - Separating Wafer Leaves, Rice- paper Leaves and the Like from a Magazine

Info

Publication number: GB2079260A
Application number: GB8118831A
Authority: GB
Original assignee: Hebenstreit GmbH
Current assignee: Hebenstreit GmbH
Priority date: 1980-06-28
Filing date: 1981-06-18
Publication date: 1982-01-20
Also published as: DE3024602A1; AT376546B; GB2079260B; ATA141181A

Abstract

In a device for removing wafer leaves, rice-paper leaves or the like from a magazine comprising a stacker shaft 2, the bottom leaf 1 is removed by frictional withdrawal by a conveyor 5. An additional force of attraction is applied to the leaf by a vacuum box 11 having a perforated top, the conveyor having perforations 8 which can be selectively blocked by slide 15. The length and width of the effective area of attraction can be varied. <IMAGE>

Description

SPECIFICATION Improvements in or Relating to Methods and Devices for Removing Wafer Leaves, Rice Paper Leaves and the Like From a Magazine This invention relates to methods and devices for removing wafer leaves, rice-paper leaves or the like from a magazine.

In the art of producing confectionery containing leaf-shaped wafer material or the like products, there exist two preferred possibilities of removing the freshly baked wafer leaves, which are delivered, for example, by an automatic wafer baking machine, from a magazine comprising a stacker shaft that receives them and of feeding them to the units which process them further.On the one hand, this is effected in a conventional manner in that the respective lowest wafer leaf contained in the stacker shaft is withdrawn by means of a belt conveyor from this shaft in a positive manner, in that prongs, members, bulges, knobs or the like parts, which are fitted to the conveyor belt, engage behind it and, gripping through appropriate slots provided in the stacker shaft bottom, if the stacker shaft is downwardly sealed by a solid bottom, in the direction of withdrawal, push the respective wafer leaf that is to be withdrawn in front of them. As experience has shown, this entails the risk, which virtually cannot be eliminated, that the positive engagement of these drivers in the rear edge of the wafer leaf to be withdrawn causes the same to be damaged, in that wafer leaf material zones of greater or lesser size are crushed, crumble or break off.Apart from the fact that this not only impairs the quality of the later completed wafer end product and usually causes a loss that is not inconsiderable in the output rate of a total production line for such a wafer end product, in that these edge zones have later to be separated as useless waste, it has turned out to be particularly disadvantageous that with this known method of removing wafer leaves from a magazine impairments in the operation of withdrawing the wafer leaves from the magazine usually come about already in the withdrawal area due to the wafer material parts which have unavoidably crumbled or broken away from the wafer leaf complex, thus making necessary servicing intervals in relatively rapid succession, without taking into account the even considerably weightier disadvantage which, as experience has shown, usually comes about due to the fact that wafer leaves having such frayed or missing places of the described kind usually give rise, during the course of their further processing, for example while they are coated with a suitable filling consisting of cream, nougat, chocolate, jam or the like, to the production plant being contaminated in the respective further processing zone, such as the filling application station, whereby not only the external aesthetic appearance of the completed wafer end product is considerably impaired and the quality thereof is thus reduced to the extent of being useless but there are also usually caused down-times which become necessary because the plant has from time to time to be freed from such filling compound contamination.And, as experience has shown, the effect of this trouble is the most unfavourable, as regards operating costs, the more often such servicing has to be carried out because each servicing usually necessitates a shutdown of the entire production plant with all the upstream and/or downstream units.

In order to avoid these known disadvantages to the largest possible extent, one has already taken the step of withdrawing the wafer leaves in a generic method frictionally from the stacker shaft of the magazine, in that the respective lowest wafer leaf in the stacker shaft is driven by frictional grip by means of a belt conveyor, which has an appropriate belt roughness, and is withdrawn from this shaft. However, an adequate frictional grip between the underside of the wafer leaf to be withdrawn and the conveyor belt surface coming into operative contact therewith is the pre-condition for a satisfactory functioning of this known method.But, as is known, the quality of this frictional grip is not least a function of the supporting force normal to a belt conveyor with which the wafer leaf to be withdrawn rests on the belt conveyor, in other words of the effective weight of the wafer leaf contents in the stacker shaft of the magazine. This weight or, accordingly, the number of wafer leaves present in the stacker shaft therefore has to be as high as possible in this known method of frictional withdrawal of wafer leaves from the magazine.

But it is precisely this high weight which is necessary for a good driving effect on the lowest wafer leaf in the stacker shaft of the magazine and which rests on this leaf that results in another essential disadvantage. For frequently wafer leaves provided with a so-called fine cart6 have to be handled, that is to say wafer leaves which have on at least one of their surfaces projections which are curved over a large area and are delicate and not infrequently also have a height above the base level of the wafer leaf surface that is not inconsiderable. However, precisely such a fine cart6 is particularly sensitive to the application of force in the direction of the wafer leaf plane, such as is indispensable for the frictional leaf drive.As experience has shown, virtually unavoidable mechanical demage is caused to this fine cart8, which usually considerably reduces the quality of the completed wafer end product, for example a multi-layer wafer block provided with one or several filling layers. For this reason, one has, in practical operation, always given preference in such cases to the method of positive withdrawal from the stacker shaft of a magazine of such wafer leaves provided with fine cart6 and has accepted the other disadvantages described at the beginning.

Not infrequently rice-paper leaves are used as parts of, for example, confectionery end products, for example for macaroon biscuits or the like. An even more important difficulty of quite a different nature has to be overcome here. For, as is known, it is a characteristic of rice-paper leaves to adhere closely to one another with their surfaces, for which reason such rice-paper leaves have hitherto proved to be virtually unsuitable for machine handling in conjunction with the stacking and removal from a magazine. If one hitherto wanted to use such rice-paper leaves for further processing by machine, for example by applying small heaps or blobs of macaroon compound or the like, then the respective rice-paper leaves had until now to be placed by hand or through a turnstile on the belt conveyor or the like delivering them to the further processing station.In both cases of such loading of these rice-paper leaves, namely by hand or, for example, by means of a turnstile or rotary fan or the like, experience has shown that the risk of the mechanically highly sensitive leaf material breaking or being chipped cannot be ruled out. A true withdrawal of such highly fragile leaf material from a magazine by machine and, if required, even by automatic control with a jerk-free transfer thereof to an onward transportation unit while avoiding mechanical stresses transversely to the leaf material plane has so far been impossible.

However, for a fully automatically working plant for handling and further processing rice-paper material into the finished end product, which plant furthermore operates with extreme operational reliability and, bound up therewith, requires very little maintenance, which has not been considered possible until now, such a possibility of stacking or buffering such material in a magazine and of withdrawing the same therefrom by frictional grip alone, and this in its own leaf material plane, would be highly desirable.

According to one aspect of the invention there is provided a method for removing wafer leaves, ricepaper leaves or the like from a magazine comprising a stacker shaft, for receiving one or more wafer leaves or the like, by frictional withdrawal of the bottom wafer leaf or the like from the stacker shaft in the leaf plane, in which an additional force of attraction in the direction of a withdrawal element is applied to the respective wafer leaf or the like to be withdrawn from the stacker shaft, at least during the withdrawal thereof from the stacker shaft.

According to another aspect of the invention there is provided a device for removing wafer leaves, rice-paper leaves or the like from a magazine comprising a stacker shaft, for containing one or more wafer leaves or the like, by the frictional withdrawal of the bottom leaf or the like from the stacker shaft by means of a withdrawal element which imparts to this leaf or the like a movement in its plane comprising a force intensification unit which supports the force application of the withdrawal element for the withdrawal of the bottom leaf or the like.

In an expedient further development of the method according to the invention, provision may be made for the wafer leaves or the like to be held fixed relative to the movement of the withdrawal element, at least during the withdrawal thereof from the stacker shaft. It is preferable if the wafer leaves or the like are held fixed relative to the withdrawal element.Although it is not absolutely necessary for the basic function of the invention, it is most expedient for operational reasons if the additional force of attraction in the direction of the withdrawal element or the force for fixing the wafer leaves or the like relative to or on the withdrawal element is still maintained when the rear edge of the wafer leaf or the like has left the stacker shaft since, for the solution of a subordinate problem not mentioned so far, this subordinate inventive conception advantageously simultaneously furthermore causes the wafer leaves or the like withdrawn from the stacker shaft to be withdrawn in a position that is exactly aligned by the wall of the shaft without any change to them, and to be moved on, at least for a distance that is not inconsiderable after their rear edge has come clear of the stacker shaft, and to be fed in an unchanged fixedly held position via the same withdrawal element or possibly a different element to the next further processing station. For by this means it is possible to bring about further advantages which may be relevant both constructionally and procedurally and which are capable of forming the basis for further economies with respect to investment and operating costs.

Devicewise, the force intensification unit may be designed, in an expedient further development of the invention, as a fixing unit for fixing the wafer leaves or the like relative to the movement of the withdrawal element at least during the withdrawal thereof from the stacker shaft.

Expediently, the force intensification unit may be designed as a fixing unit for fixing the wafer leaves or the like on the withdrawal element itself.

In this connection, it is particularly expedient if there can be applied by the force intensification unit to the respective wafer leaf or the like to be withdrawn an additional force of attraction, which is directed so as to be normal to the lower surface thereof, in the direction of the withdrawal element. If the force intensification unit is of an appropriate design, this force of attraction can still be exerted on the withdrawn wafer leaf or the like when the rear edge thereof has already come clear of the stacker shaft, that is to say when the entire wafer leaf or the like has left the stacker shaft.

Depending on the nature of the surface 4 condition of the wafer leaves or the like to be withdrawn, the surface measurements and/or the existing roughness thereof in combination with the corresponding flexibility of the withdrawal element, the additional force of attraction in the direction of the withdrawal element or the force for fixing the wafer leaves or the like relative to or on the withdrawal element can be put into effect over at least a portion of the lower surface of the wafer leaf or the like to be withdrawn, for which purpose there is then provided devicewise, in an expedient further development of the invention, that the additional force of attraction will be applicable to at least a portion of the lower surface of the wafer leaf or the like to be withdrawn.However, in other cases, it may be preferable if the additional force of attraction in the direction of the withdrawal element or the force for fixing the wafer leaves or the like relative to or on the withdrawal element is put into effect over the entire lower surface of the wafer leaf or the like to be withdrawn. For this purpose, the additional force of attraction can then be applied, according to an alternative configuration, to the entire lower surface of the wafer leaf or the like to be withdrawn by the force intensification unit.

Both for constructional reasons and under the aspect of a particularly simple conduction of the method according to the invention, an inventive further development is preferable according to which the additional force of attraction in the direction of the withdrawal element or the force for fixing the wafer leaves or the like relative to or on the withdrawal element is applied to these leaves by vacuum action. For this purpose, a subordinate inventive conception, which further develops the device according to the invention in this respect, provides for the additional force of attraction to be applied by the force intensification unit to the wafer leaf or the like to be withdrawn by vacuum action.For not only can such vacuum action be produced with a relatively low expenditure of energy and therefore at a low cost in a sufficiently effective manner, but the appropriate suction air is also virtually without exception available to an adequate extent in appropriate production enterprises so that it can be utilised without an impairment of its other functions.An additional advantage is furthermore provided in that such a constructional form of the invention is virtually self-cleaning, in other words the operating time between two maintenance periods, which may be necessary, can be increased to a true maximum, unless shutdowns of the device according to the invention for the purpose of servicing the same on the ground of eliminating crumbs or broken particles of wafer leaf material or the like become altogether unnecessary, in that the suction air, which is required for maintaining the vacuum action to be employed, automatically ensures the removal of crumbs or smaller particles of the leaf material which has been withdrawn from the stacker shaft if an appropriate separating unit is provided in the suction line connection to the vacuum pump.

In a particularly trouble-free construction, which therefore requires little maintenance and is consequently economic, both for constructional reasons and for reasons of the operational conduction of the process, the wafer leaves or the like are withdrawn from the stacker shaft by means of a belt conveyor, during which process there is exerted on them on additional adhesive force or fixing force that is normal to the conveyor belt, in that the withdrawal element is designed as a belt conveyor which is provided beneath the stacker shaft and can be brought into operative contact with the lowest wafer leaf or the like contained therein and in that an additional adhesive force or guiding force that is normal to the conveyor belt can be applied to this wafer leaf or the like by the force intensification unit.In an expedient further development, the withdrawal element may be designed as a multi-belt conveyor, the additional adhesive force or fixing force being applicable by the force intensification unit to the lowest wafer leaf or the like which is located in the stacker shaft and is to be brought into operative contact with the conveyor belts through vacuum action that is effective between the conveyor belts, so that the wafer leaves or the like are withdrawn from the stacker shaft by means of this multi-belt conveyor and the additional adhesive force or fixing force is applied to the wafer leaves or the like by vacuum action that is effective between the conveyor belts of the multi-belt conveyor.Alternatively, provision may be made, on the other hand, for the withdrawal element to be designed as a multi-belt conveyor or as a wide-belt conveyor, the additional adhesive force or fixing force being applicable by the force intensification unit to the lowest wafer leaf or the like which is located in the stacker shaft and is to be brought into operative contact with the conveyor belts or the conveyor belt through vacuum action that is effective through the conveyor belts or conveyor belt, so that the wafer leaves or the like are withdrawn from the stacker shaft by means of this multi-belt conveyor or wide-belt conveyor and the additional adhesive force or fixing force is applied to the wafer leaves or the like by vacuum action that is effective through the conveyor belts or conveyor belt.

Expediently the wafer leaves or the like can be withdrawn from the stacker shaft at a distance from one another, thus allowing, depending on the subsequent processing operation, procedural simplifications and possibilities for an increase in time of the throughput rate of wafer leaves or the like or a correspondingly compact construction of the production line comprising the device according to the invention, in that a proportion of a wafer leaf singling operation, which may become necessary, is advanced to the process of withdrawing the same from the stacker shaft of the magazine.On the other hand, on account of other procedural parameters, it may be desirable, for example during the delivery of the wafer leaves or the like to a filling application unit, wherein they are coated with a filling compound in the form of cream, nougat, chocolate, jam or the like by the contact method or by the film application method or even by the combined contact/film application method, that the wafer leaves or the like are withdrawn from the stacker shaft in continuous succession, one abutting the other.According to an expedient further development of the method according to the invention, this, too, is possible with the advantage that the extension of the conveyor system of the production line comprising the device according to the invention can be kept extremely short between the magazine or the stacker shaft thereof and the filling application unit and that valuable constructional space can thus be saved.

A particularly reliable driving effect comes about if, according to an inventive further development of the device, the force intensification unit has an effective force intensification zone which extends from the withdrawal end, in other words the downstream stacker end, at least over a portion of the length, measured in the direction of withdrawal, of the wafer leaves or the like to be withdrawn, opposite to the direction of withdrawal. In many cases, it will be expedient if the force intensification zone opposite to the direction of withdrawal equals at least a full total length of a wafer leaf or the like in the direction of withdrawal.For then a maximum of fixation of the wafer leaf or the like to be withdrawn from the stacker shaft comes into action on the withdrawal element precisely when the additional holding or fixing force is applied by vacuum action, particularly if this element is constructed as a belt conveyor of the described kind. For the rest, it is well possible that the effective force intensification zone opposite to the direction of withdrawal is longer than the total length of a wafer leaf or the like measured in the direction of withdrawal. By a suitable dimensioning of the flow resistance characteristics in the part of the effective force intensification zone that is not covered by a wafer leaf to be withdrawn and is located upstream thereof it is in most cases possible to effect an adequate adaptation in co-ordination with the associated vacuum values.On the other hand, it may well prove to be expedient if, in an expedient further development, the effective force intensification zone can be set in its length, preferably even automatically. Provision may also be made for the effective force intensification zone to be adjustable in its width.

For the rest, it is preferable in most applications if the force intensification unit has an effective force intensificatoin zone which extends in the direction of withdrawal from the withdrawal end of the stacker shaft at least over a portion of the length, measured in the direction of withdrawal, of the wafer leaves or the like to be withdrawn.By this means, it is advantageously ensured that the wafer leaves or the like which are being withdrawn are still held fixed on the withdrawal element, at least over their total length, also during that part of this operation in which an adhesive action is actually only still provided in their tail zone, the length of the effective force intensification zone in the direction of withdrawal being preferably so dimensioned that the respective wafer leaf or the like withdrawn is transported further held fixed in the direction of withdrawal over more than its total length, which can even be carried so far that this fixing is maintained until the respective wafer leaf or the like is transferred to the further processing plant part of the production line comprising the device according to the invention.

An inventive further development of a device according to the invention, according to which the force intensification unit has a suction plate which is provided beneath the stacker shaft bottom, which is preferably open over the entire surface, and through which there can be maintained an air flow from its end that is close to the stacker shaft bottom to its end that is remote from the stacker shaft bottom, is particularly suitable for the purpose of supplementarily equipping existing generic devices operating with a frictional withdrawal of the wafer leaves or the like from the stacker shaft of the magazine. In an expedient further development of this subordinate inventive conception, there may be maintainable at the suction plate end that is remote from the stacker shaft a vacuum with respect to its end that is close to the stacker shaft.Furthermore, it may be expedient to form the suction plate from airpermeable material, for example from suitably stiffened felt, or from a wire netting or plastics material lattice-work, for example in the form of a plastics material injection moulding, the end thereof that is close to the stacker shaft bottom then being coverable with a felt or mat layer.

However, on the other hand, in an alternative constructional form, the suction plate may have air passage ports which connect its end that is remote from the stacker shaft bottom to its end that it close to the stacker shaft bottom. These air passage ports may be open without any baffle plates or flow restrictors or the like if their dimensions are such that the effective force intensification zone is formed by a suction zone of the suction plate with a flow resistance so as to maintain a pressure gradient between the end that is close to the stacker shaft bottom and the end that is remote from the stacker shaft bottom.

However, on the other hand, the air passage ports of the suction plate may have baffle plates or other suitable flow restrictors, so as to maintain the appropriate vacuum at an adequate level at the end that is remote from the stacker shaft bottom. In the interests of avoiding any unnecessary air passage flow through the suction plate, and bound up therewith a corresponding reduction of the suction pump output to be allowed for, this may go so far that the air passage ports in the suction plate are each sealed by an automatically closing valve which will only open on account of the weight that is operative from the end thereof that is close to the stacker shaft. Such seals for the air passage ports of the suction plate may be formed, for example, by spring-loaded balls which engage, with a cap-like part, through the air passage ports and project beyond the level of the suction plate surface that is close to the stacker shaft bottom.

According to an extending subrodinate inventive conception, for a device according to the invention wherein a vacuum acts on the respective wafer leaf or the like to be withdrawn through the conveyor belt or conveyor belts of the withdrawal element, which is designed as a belt conveyor, each conveyor belt may advantageously have, over a zone that is aligned transversely to the direction of withdrawal with the air passage ports in the suction plate, a continuous succession of air passage ports which are provided at intervals which, compared to the spacing of the air passage ports in the suction plate, are different, preferably shorter, in the direction of withdrawal.In this way, the additional expenditure for a soft or elastic design of the suction plate surface, which in most cases is not required as regards the surface configuration of the wafer leaves or the like to be withdrawn, becomes unnecessary. However, it is always ensured that a constantly active adhesive force or holding or fixing force respectively acts without interruption on the wafer leaf or the like to be withdrawn, in that, due to the measure of this 'subordinate inventive conception, provision is made for specific conveyor belt air passage ports to overlap specific suction plate air passage ports, during the course of the onward movement in the direction of withdrawal of the conveyor belt or belts provided with the air passage ports, for a certain period of time so that the vacuum which is active at the suction plate end that is remote from the stacker shaft bottom acts through these overlapping ports on the underside of the wafer leaf or the like to be withdrawn.

Furthermore, it is expedient if, for changing the effective length of the suction zone, there is provided at the suction plate end that is remote from the stacker shaft bottom a slide which seals the suction zone of the suction plate from the passage of air over an adjustable length and is operable in the direction of withdrawal.According to another refinement of the inventive conception aiming at a universality of applications for the device according to the invention through purposeful adjustment possibilities for the effective suction zone of the suction plate, there may be provided for changing the effective width of the suction zone at the suction plate end that is remote from the stacker shaft bottom, along at least one edge strip zone of the suction plate, preferably along both edge strip zones thereof, respectively one slide which seals this one edge strip zone or these two edge strip zones over an adjustable width from the passage of air and is operable transversely to the direction of withdrawal.In a construction with two slides for the variable width sealing of both edge strip zones of the suction zone, both slides may expediently be operable simultaneously in opposite directions.

Due to these measures, which aim at setting the effective suction plate suction zone in length or width, the subordinate partial problem of allowing the device according to the invention to be easily, quickly and conveniently adapted to different sizes of wafer leaves or the like to be withdrawn, is solved with means which are extremely simple both constructionally and operationally and which are accordingly altogether economic, in that the previous stacker shaft of the magazine is quite simply exchanged for a stacker shaft that corresponds to the changed dimensions of the leaves and in that the appropriate lengthwise and/or widthwise adaptation of the effective suction zone of the suction plate of the force intensification unit is effected in an appropriate co-ordinated manner. It is evident that it is possible to bring about considerable change-over time savings here.

It is precisely in view of the extreme fragility of specific leaf materials to be handled, on account of, for example, extremely large surface dimensions and/or a particularly thin material thickness and/or a markedly short or fragile consistency, such as, in particular, large-size ricepaper leaves or the like, that it may be highly valuable, specifically in a constructional form of the invention wherein the withdrawal element for the wafer leaves or the like is designed as a belt conveyor, if it can be ensured that any risk of deflections of any kind of the wafer leaves or the like, resulting from the vacuum action exerted on the lower surface of the wafer leaf or the like to be withdrawn, is reliably avoided.According to another subordinate inventive conception, the invention provides in such a construction of the device according to the invention for the suction plate to be designed for this purpose as a supporting plate for the belt conveyor conveyor belt or conveyor belts sliding over it. By this means, an exact spaced association of the conveyor belt surface coming into operative contact with the lower surface of the wafer leaf or the like to be withdrawn from the stacker shaft is brought about in an advantageous manner and is maintained over the entire lower surface of the wafer leaf or the like to be withdrawn. Even if the suction draught acting on the lower surface of the wafer leaf or the like to be withdrawn is extremely strong, this prevents any deflections or distortions thereof, which might give rise to the leaf being damaged.

According to another inventive further development, a design of the device according to the invention that is particularly simple and therefore also particularly economic with respect to production technique comes about in that the suction plate is formed by a flat upper part of a vacuum tank. By this means, practically the upper zone of such a vacuum tank, which is considered to be highly expedient in any event for an effective functioning of the invention in a continuous operation, is utilised for defining a straight reception plane for the wafer leaf or the like to be withdrawn from the stacker shaft, and it is furthermore reliably ensured that, still within the zone of the stacker shaft, the lowest wafer leaf or the like contained therein and to be withdrawn therefrom is so pulled down by the vacuum action to this reference plane, which practically serves as a standard level, even if warpings or distortions of its material are present, that it can neatly pass through the stacker shaft outlet opening at the withdrawal direction end, even if in an uninfluenced condition its configuration is not quite plane in the stacker shaft, and that damage to such wafer leaves or the like is reliably avoided even if for any reason, which has its origin, for example, in the baking zone or the delivery path to the stacker shaft, these have a shape and design which would normally destine them to be waste.

By this means, it is in turn possible to bring about not only an increase that is not inconsiderable in the economy of the entire production process for the finished end product by avoiding any unnecessary waste but also a particularly exact adaptation of the units or plant parts of a production line which are provided downstream of the device according to the invention to the output of the respective automatic baking machine or to the feeder conveyor unit which is provided downstream thereof, to the magazine.

This, in turn, has an advantageous cost-lowering effect. For further increasing the universality of the applications of the device according to the invention, it is expedient if, in a further development of the invention, the force intensification unit can be adjusted or positioned in its height with respect to the stacker shaft bottom. For in this way it is with very simple means possible to bring about quickly and conveniently any necessary adaptation to different leaf materials to be withdrawn, particularly with respect to the thickness and/or the carve' height thereof.Particularly if, in this preferred constructional form of the invention, the force intensification unit is furthermore mobile as a whole, there come about many possibilities for using a single such device according to the invention as supplementary equipment to existing and running production plants, particularly with respect to the individual adaptation thereof to leaf materials which vary from time to time, such as, for example, wafer leaves, rice-paper leaves or the like whose thickness of material differs.For the rest, this may, if necessary, go so far that such a constructional form of the invention is automatically adaptable from leaf to leaf to varying designs of leaf material to be withdrawn from the stacker shaft by an appropriate control unit, in that, on the one hand, the material thickness of the respective wafer leaf or the like to be withdrawn is sensed by suitable known sensors and in that an appropriate slaving drive for the height adjustment of the force intensification unit or the suction plate thereof is actuated via a nominal/actual value comparator.

Hereinafter, the invention will be explained in more detail, purely by way of example, with reference to a preferred exemplified embodiment which is diagrammatically shown in the drawings, in which: Fig. 1 shows a longitudinal section through a device according to the invention in the direction of delivery or withdrawal for wafer leaves, rice paper leaves or the like to be withdrawn from a magazine, and Fig. 2 shows a top view of the device shown in Fig. 1 in the direction of the arrow A.

A stacker shaft of a magazine, which has not been designated in detail, for wafer leaves 1, ricepaper leaves or the like is designated 2. In the exemplified embodiment shown, the entire area of the bottom of the stacker shaft 2 is open. The wafer leaves 1 contained in the stacker shaft 2 lie with their underside on the free surface of the upper run 5a of the conveyor belt 5 of a belt conveyor, which is designed as a wide-belt conveyor and is designated 3 as a whole, or on the upper runs of several conveyor belts 6, which are provided in parallel, if the belt conveyor is designed as a multi-belt conveyor.The conveyor belt 5 or the conveyor belts 6 pass over two deflection pulleys 4, of which that which is not driven is depicted in the exemplified embodiment shown, while, in order to illustrate that the belt conveyor 3 need not only serve as a mere withdrawal conveyor for the device according to the invention but may also fulfil a more farreaching delivery function, for the withdrawn wafer leaves 1 or the like to downstream units or plant parts of the production line which includes the device according to the invention, it is shown downstream of the stacker shaft 2 with a broken upper run 5a and a likewise broken lower run 5b.

To this extent, the construction is a conventional one of a generic device.

As can be seen in Fig. 2, the belt conveyor 3 may have a different constructional form. In the upper half of Fig. 2, there is shown a conveyor belt 5 which is shown only in half its width in the representation but does extend downwards in the same way beyond the dash-dotted centre line.

This is thus a wide-belt conveyor. This conveyor belt 5 has, - as shown over an effective width d, of which only one half d/2 is depicted, several rows of air passage ports 8 which are provided at a hole division tin the direction of withdrawal F.

In the lower half of Fig. 2, there is depicted a different constructional form of the device according to the invention, wherein the belt conveyor 3 is designed as a multi-belt conveyor comprising three conveyor belts 6, of which in Fig. 2 one is depicted right at the bottom and one half of a central conveyor belt 6 is depicted along the dash-dotted centre line. These conveyor belts run in parallel at a distance a from one another.

They, too, have - as shown - air passage ports 8 which are provided over an effective width zone e in one row or - as in the exemplified embodiment shown - in several rows at regular intervals tin the direction of withdrawal F.

Beneath the upper run 5a of the belt conveyor 3, as shown in Fig. 1, a force intensification unit, which is designated 10 as a whole, is so arranged that it is located, on the one hand, beneath the bottom zone of the stacker shaft 2, the possibility of it extending upstream thereof to some extent also being given, and, on the other hand, some distance downstream of the withdrawal end 9 of the stacker shaft 2. This force intensification unit 10 comprises a vacuum tank 11 which is connected through an intake connection 14 and an onward conduction line, which is not shown, to a suction pump which is also not shown and by means of which a vacuum with respect to the atmospheric pressure is maintained in the interior of the vacuum tank 11.The upper zone of the vacuum tank 11 is designed as a flat suction plate 12 which, in the exemplified embodiment shown, engages, with a zone that is impermeable to air, beneath the stacker shaft 2 bottom zone part that is located upstream and over its remaining zone has air passage ports 13 which - as shown are provided at a division T, which is larger than the hole division t of the air passage ports 8 in the conveyor belt 5 (wide-belt conveyor) or 6 (multibelt conveyor), in the withdrawal direction, in an orientation transversely to the direction of delivery F which is such that the arrangement centres of the rows of air passage ports 13 in the suction plate 1 2 of the force intensification unit 10 and the lines of the location of movement of the associated air passage ports 8 in the respective conveyor belt 5 or 6 of the belt conveyor 3 overlap. The maximum width of the effective suction zone of the suction plate 12 equals, in the exemplified embodiment shown in the upper half of Fig. 2, the width of the total arrangement of the air passage ports 8 in the conveyor belt 5 of the wide-belt conveyor 3. In the exemplified embodiment shown in the lower half of Fig. 2, there are provided two possibilities which are graphically shown in the same manner, as can be seen in Fig. 2.For, on the one hand, provision may be made for the suction plate 12 of the force intensification unit 10 to have an arrangement of air passage ports 13 only in the zone a, over which there do not run any conveyor belts 6 of the multi-belt conveyor 3. These conveyor belts 6 than do not have to be provided with any air passage ports 8, for the adhesive force for fixing the wafer leaves 1 or the like to be withdrawn from the stacker shaft 2 then only acts in the zones a which are not covered by the conveyor belts 6 or beneath which the conveyor belts 6 do not engage. But, on the other hand, only the zones of the suction plate 12 over which conveyor belts 6 of the multi-belt conveyor 3 run may instead be equipped with air passage ports 13 in the same way as has been explained relative to the afore-described exemplified embodiment in which a wide-belt conveyor is used.This variant, too, is shown in the lower half of Fig. 2. And, finally, there may be used a combination of these two constructional forms of the invention using a multi-belt conveyor, preferably whenever a force intensification unit 10 with a suction plate 1 2 is provided, which has been conceived for use with a wide-belt conveyor but which is to be used for any reason, as may be the case, for example, if the size of the wafer leaves 1 or the like to be withdrawn from the stacker shaft 2 is changed.

As stated, the suction plate 12 has, in the bottom zone of the stacker shaft 2, a length which determines the length c of the effective force intensification zone of the force intensification unit 10 and which is smaller than the length / of the wafer leaves 1 or the like to be withdrawn from the stacker shaft 2. This may be favourable for specific constructional forms of the goods to be withdrawn from the stacker shaft 2, depending on the surface extension, material thickness, consistency and, in particular, the extent of distortion thereof.If, for example, the latter is particularly large, it may be necessary to exert a straightening action on the entire lower surface of the lowest wafer leaf 1 or the like to be withdrawn from the stacker shaft 2 or at least on the largest portion thereof, so as to enable this wafer leaf 1 or the like to pass through the withdrawal opening 7 of the stacker shaft 2. In such a case, the shown air-impermeable upstream suction plate 1 2 zone is then dispensed with or this plate is provided so much farther upstream that the effective length c of its suction zone equals totally or at least for the major part the length I of the wafer leaves 1 or the like to be withdrawn in the direction of withdrawal F.

Downstream of the withdrawal end 9 or the withdrawal opening 7 of the stacker shaft 2, the suction plate 1 2 also has an effective suction zone, and the force intensification unit 10 thus has an effective intensification zone, whose length b is advantageously at least as large as the length / of the wafer leaves 1 or the like withdrawn from the stacker shaft 2 in the direction of withdrawal. However, the length b of this effective force intensification or suction zone may advantageously be larger, and even considerably larger, than this single length /.

In order also to allow the effective length c to be adapted during the operation of the device according to the invention to the respective requirements determined, in particular, by the characteristics of the wafer leaves 1 or the like to be withdrawn from the stacker shaft 2, there may be provided -- as is merely diagrammatically indicated in Figs. 1 and 2 - a facility of adjustment for this effective zone c, for example in the form of a slide 1 5 which is actuatable via an actuating means, of which only a portion of a connecting arm 1 6 is shown, in the direction of the double arrow S and which is so arranged beneath the suction plate 1 2 of the force intensification unit 10 that the air passage ports 13 thereof are covered over the full length c or else only over a partial length thereof and are thus blocked to a greater or lesser extent for the passage of air from the end that is close to the stacker shaft bottom into the interior of the vacuum tank 11.

As is shown merely diagrammatically, the effective width of the suction plate 1 2 may also be adjustable. For this purpose, a variation facility may be provided in one or both edge strip zones extending along its side wall in that - as is shown in dash-dotted lines in Fig. 2 only for the purpose of illustration of way of example provision is made for one or several slides 17 which are movable in the direction of the suction plate centre or in the opposite direction according to the double arrow R. In Fig. 2, there is indicated only in the upper half thereof such a slide 1 7, of which a closing position is shown in another dash-dotted line 17'.Of course, a corresponding slide 17 may advantageously be provided, so as to be symmetrical about the central line, also in the lower half shown in Fig. 2 as a facility of setting the effective width of the suction zone of the suction plate 12. For reasons of clarity, these width setting slides 1 7 are not shown in Fig. 1.

The same applies in Fig. 2 to the driving mechanism for these slides 1 7. This mechanism may, however, advantageously be so designed that both slides, which engage beneath opposite edge strip zones of the suction plate 12, are simultaneously operable in opposite directions, which can be brought about, for example, by a mechanical drive design in which a quadrant construction is used. However, for the rest, these width setting means 17 operate in the same way as has been described hereinbefore in respect of the length setting means 15, 1 6 for the effective length c of the suction zone of the suction plate 12.

Without considering details which are known 'per se' to one skilled in the art, the double arrow H in Fig. 1 furthermore symbolises that for a further adaptation of the device according to the invention to different thickness dimensions of the wafer leaves 1 or the like to be withdrawn from the stacker shaft 2 the entire force intensification unit 10 or the vacuum tank 11 thereof together with the suction plate 12 or - if this plate is designed independently of the vacuum tank 11 - only this plate can be adjustable in height with respect to the bottom of the stacker shaft 2 and can be positioned with respect to this latter.In this connection, the belt conveyor 3 should be provided in a vertical position which is such that its upper run 5a is situated at a maximum setting distance from the bottom of the stacker shaft 2 when the suction plate 12 in in its lowest setting position. By raising the suction plate 12, it is then possible to reduce its distance from the stacker shaft bottom, the belt conveyor 3 upper run, which slides over its surface that is close to the stacker shaft bottom, following this positioning movement since the belt conveyor 3 idler pulley, which is provided anyway, follows this deflection and ensures the presence of a sufficient conveyor belt length.

In Figs. 1 and 2, there is shown an operating position of the setting means 1 5, 1 6 for the effective length c of the force intensification unit 10 wherein this latter is virtually switched off.

However, if the slide 1 5 is retracted by a suitable dimension opposite to the direction of withdrawal F, preferably to such an extent that the entire airpermeable length c of the suction plate 12 becomes active, with the belt conveyor 3 incidentally running, the wafer leaves 1 or the like contained in the stacker shaft 2 are removed therefrom continuously, in that always the lowest one thereof is over its entire surface or at least the greater part thereof pulled down onto the upper run 5a of the conveyor belt 5 by the force of attraction or fixing which is active through the suction plate 12 and the upper run 5a of the conveyor belt 5 (or the conveyor belts 6).As regards the driving effect exerted on the leaf, the friction contact between the wafer leaf 1 or the like and the conveyor belt 5 or conveyor belts 6 is virtually only of subordinate importance since the additional force of attraction applied by the force intensification unit 10 holds the wafer leaf 1 or the like fixed on the upper run 5a so that this leaf can easily pass through the slot-shaped outlet opening in the stacker shaft 2, regardless of any previous buckling or distortion phenomena, and is transported further on the upper run 5a, while being held fixed, in an orientation that is defined by the position of the stacker shaft 2 relative to the belt conveyor 3, until it leaves the effective length b of the suction plate 1 2 suction zone that is located downstream of the stacker shaft 2.Due to the fact that the frictional driving of the leaf is virtually no longer of any importance, it is no longer necessary that the contact-pressure weight acting on the wafer leaf 1 or the like to be withdrawn should be kept at a corresponding level. Accordingly, there is also no longer any need for providing a substantial stacking height of the wafer leaves 1 or the like contained in the stacker shaft 2. On the contrary, this height can be reduced to a minimum, which may even go so far that only a single wafer leaf or the like needs to be contained in the stacker shaft 2 without impairing the withdrawal effect exerted on the wafer leaf 1 or the like to be withdrawn from the stacker shaft 2. By this means, the fine cart6 elevations of the wafer leaves 1 or the like, which have been only diagrammatically indicated in Fig.

1, are treated mechanically in a very careful manner and any damage thereto, involving the disadvantageous consequences described at the beginning, is effectively avoided.

For the rest, it has surprisingly turned out that, particularly if the possibilities of using the height positioning of the suction plate 1 2 in the direction of the double arrow H with respect to the stacker shaft bottom are utilised, it is possible to control the difficulties arising during the handling of ricepaper material which were hitherto considered to be insurmountable, in that there is rendered possible, on the one hand, a large-surface fixing on the withdrawal element of the lowest ricepaper leaf to be withdrawn from the stacker shaft 2 and, on the other hand, a very fine setting by the appropriate dimensioning of the clear outlet height of the outlet slot 7 of the stacker shaft 2 by ' means of the appropriate positioning of the suction plate 1 2 with respect to the stacker shaft bottom. By this means, a rice-paper material handling that is impact-free and avoids mechanical stresses which are normal to the surface becomes possible, there being additionally opened up many possibilities for a suitable automation thereof.

Wafer leaves may be formed by extrusion and subsequent expansion.

With this embodiment there is provided with particularly simple and also low-cost means a possibility of storing or buffering in a magazine virtual!y without any risk even highly fragile wafer leaves, rice-paper leaves or the like, even if the dimensions thereof are mechanically extremely unfavourable, as may be the case, for example, if the surface size of the leaf material is particularly large and/or if the material thickness is particularly thin and/or if the consistency of the leaf material is very brittle or short, and of frictionally removing them from this magazine when necessary, even if this leaf material, be it wafer or rice-paper leaf material or the like, has a so-called fine cart6 on at least one of its surfaces, without any risk of the leaf material as such or the fine cart' thereof being damaged, there being furthermore reliably ensured, on the one hand, that the length of operation between two maintenance periods, which are necessary under the aspect of cleaning the withdrawal elements for these wafer leaves, rice-paper leaves or the like and, in particular, the downstream further processing units of a production plant, which includes the magazine containing the wafer leaves, rice-paper leaves or the like, not only by the removal of crumbs and/or broken scraps of such leaf material but, in particular, also by the removal of any contamination caused by filling compound or the like and only caused by such missing places in the delivered leaf material, is extremely long or that shutdowns for this reason become completely unnecessary, thus increasing the economy of the entire production process in a manner which has so far not been considered possible, also with respect to avoiding any impairment of the operation of downstream units or parts of the plant, and, on the other hand, that a constant high quality of the finished baked goods is reliably ensured, particularly with respect to the maintenance of the external appearance thereof, even if a highly sensitive fine carve' is provided on the leaf material surfaces, and that, for the rest, there is rendered possible for the first time the automatic handling of rice-paper material as such with a control or regulation of the withdrawal thereof from the magazine, as required, free from damage due to mechanical stresses exerted thereon transversely to the surface thereof and/or due to handling or transfer jerks.

It is possible not only to handle automatically rice-paper material virtually without any risk in the desired manner, even if the leaf dimensions are extremely large, but also effectively to avoid mechanical damage to leaf material provided with fine cart6 on one or both of its surfaces, in that, despite maintaining the frictional withdrawal thereof from the stacker shaft of a magazine with its noted advantages, there is rendered possible a substantial reduction in the bearing weight of the leaf material on the withdrawal element, even down to the net weight of a single wafer leaf or the like, whereby the mechanical stress exerted on the surface carve' thereof is kept down to a minimum, as is easy to see.

It is evident that the invention is not confined to the exemplified embodiments shown and explained, but that to one skilled in the art many possibilities are open of adapting it, by means of a different combination of its features or the exchange thereof for means of identical effect, to the respective constructional factors, particularly with respect to the addition thereof to existing devices of a generic kind and/or, in particular, with respect to the operational requirements of the individual case, without thereby leaving the scope of the invention.

Claims

1. A method for removing wafer leaves, ricepaper leaves or the like from a magazine comprising a stacker shaft, for receiving one or more wafer leaves or the like, by frictional withdrawal of the bottom wafer leaf or the like from the stacker shaft in the leaf plane, in which an additional force of attraction in the direction of a withdrawal element is applied to the respective wafer leaf or the like to be withdrawn from the stacker shaft, at least during the withdrawal thereof from the stacker shaft.

2. A method as claimed in Claim 1, in which the wafer leaves or the like are held fixed, at least during the withdrawal thereof from the stacker shaft, relative to the movement of the withdrawal element.

3. A method as claimed in Claim 1 or Claim 2, in which the wafer leaves or the like are held fixed on the withdrawal element, at least during the withdrawal thereof from the stacker shaft.

4. A method as claimed in any one of the preceding Claims, in which the additional force of attraction in the direction of the withdrawal element or the force for fixing the wafer leaves or the like relative to or on the withdrawal element is still maintained when the rear edge of the wafer leaf or the like has left the stacker shaft.

5. A method as claimed in any one of the preceding Claims, in which the additional force of attraction in the direction of the withdrawal element or the force for fixing the wafer leaves or the like relative to or on the withdrawal element is applied to these by vacuum action.

6. A method as claimed in any one of the preceding Claims, in which the additional force of attraction in the direction of the withdrawal element or the force for fixing the wafer leaves or the like relative to or on the withdrawal element is put into effect over at least a portion of the lower surface of the wafer leaf or the like to be withdrawn.

7. A method as claimed in Claim 6, in which the additional force of attraction in the direction of the withdrawal element or the force for fixing the wafer leaves or the like relative to or on the withdrawal element is put into effect over the entire lower surface of the wafer leaf or the like to be withdrawn.

8. A method as claimed in any one of the preceding Claims, in which the wafer leaves or the like are withdrawn from the stacker shaft by means of a belt conveyor, and, during this process, there is exerted on them an additional adhesive force or fixing force that is normal to the conveyor belt.

9. A method as claimed in Claim 8, in which the wafer leaves or the like are withdrawn from the stacker shaft by means of a multi-belt conveyor, and the additional adhesive force or fixing force is applied to the wafer leaves or the like by vacuum action that is effective between the conveyor belts of the multi-belt conveyor.

10. A method as claimed in Claim 8, in which the wafer leaves or the like are withdrawn from the stacker shaft by means of a multi-belt conveyor or by means of a wide-belt conveyor, and the additional adhesive force or fixing force is applied to the wafer leaves or the like by vacuum action which is effective through the conveyor belts or conveyor belt.

11. A method as claimed in any one of the preceding Claims, in which the wafer leaves or the like are withdrawn from the stacker shaft at a distance from one another.

12. A method as claimed in any one of Claims 1 to 10, in which the wafer leaves or the like are withdrawn from the stacker shaft in continuous succession while they are in abutting contact with one another.

13. A device for removing wafer leaves, ricepaper leaves or the like from a magazine comprising a stacker shaft, for containing one or more wafer leaves or the like by the frictional withdrawal of the bottom leaf or the like from the stacker shaft by means of a withdrawal element which imparts to this leaf or the like a movement in its plane comprising a force intensification unit which supports the force application of the withdrawal element for the withdrawal of the bottom leaf or the like.

14. A device as claimed in Claim 13, in which the force intensification unit comprises a fixing unit for fixing the leaves or the like relative to the movement of the withdrawal element, at least during the withdrawal thereof from the stacker shaft.

1 5. A device as claimed in Claim 13 or Claim 14, in which the force intensification unit comprises a fixing unit for fixing the leaves or the like on the withdrawal element, at least during the withdrawal thereof from the stacker shaft.

1 6. A device as claimed in any one of Claims 13 to 15, in which there is applicable by the force intensification unit to the leaf or the like to be withdrawn an additional force of attraction, which is directed so as to be normal to the lower surface thereof, in the direction of the withdrawal element.

17. A device as claimed in any one of Claims 13 to 16, in which there is applicable by the force intensification unit the additional force of attraction to at least a portion of the lower surface of the leaf or the like to be withdrawn.

18. A device as claimed in Claim 17, in which there is applicable by the force intensification unit the additional force of attraction to the entire lower surface of the leaf or the like to be withdrawn.

19. A device as claimed in any one of Claims 13 to 18, in which there is applicable by the force intensification unit by vacuum action the additional force of attraction to the leaf or the like to be withdrawn.

20. A device as claimed in any one of Claims 13 to 19, in which the withdrawal element comprises a belt conveyor which is arranged beneath the stacker shaft and can be brought into operative contact with the bottom leaf or the like contained therein, and in which there is applicable by the force intensification unit to this leaf or the like, an additional adhesive force or fixing force that is normal to the conveyor belt.

21. A device as claimed in Claim 20, in which the withdrawal element comprises a multi-belt conveyor, and in which there is applicable by the force intensification unit to the bottom leaf or the like, which is located in the stacker shaft and can be brought into operative contact with the conveyor belts thereof, the additional adhesive force or fixing force by vacuum action that is effective between the conveyor belts.

22. A device as claimed in Claim 20, in which the withdrawal element comprises a multi-belt conveyor or a wide-beit conveyor, and in which there is applicable by the force intensification unit to the bottom leaf or the like, which is located in the stacker shaft and can be brought into operative contact with the conveyor belts or the conveyor belt thereof, the additional adhesive force or fixing force by vacuum action which is effective through the conveyor belts or the conveyor belt.

23. A device as claimed in any one of Claims 1 3 to 22, in which the force intensification unit has an effective force intensification zone which extends opposite to the direction of withdrawal from a withdrawal end of the stacker shaft at least over a portion of the length, measured in the direction of withdrawal, of the leaves or the like.

24. A device as claimed in any one of Claims 1 2 to 23, in which the force intensification unit has an effective force intensification zone which extends in a direction of withdrawal from a withdrawal end of the stacker shaft at least over a portion of the length, measured in the direction of withdrawal, of the leaves or the like to be withdrawn.

25. A device as claimed in Claim 23 or Claim 24, in which the effective force intensification zone is adjustable in length.

26. A device as claimed in any one of Claims 23 to 25, in which the effective force intensification zone is adjustable in width.

27. A device as claimed in any one of Claims 13 to 26, in which the force intensification unit has a suction plate which is provided beneath the stacker shaft bottom, and through which in air flow is maintainable from its end that is close to the stacker shaft bottom to its end that is remote from the stacker shaft bottom.

28. A device as claimed in Claim 27, in which at the end of the suction plate that is remote from the stacker shaft, a vacuum is maintainable relative to its end that is close to the stacker shaft bottom.

29. A device as claimed in Claim 27 or Claim 28, in which the suction plate is formed from airpermeable material.

30. A device as claimed in any one of Claims 27 to 29, in which the suction plate has air passage ports which connect its end that is remote from the stacker shaft bottom to its end that is close to the stacker shaft bottom.

31. A device as claimed in Claim 30 and using a vacuum pressure which acts through the conveyor belt or conveyor belts of the withdrawal element designed as a belt conveyor on the leaf or the like to be withdrawn, in which the or each conveyor belt has, over a zone that is aligned with the air passage ports in the suction plate transversely to a direction of withdrawal, a continuous succession of air passage ports which.

are provided at intervals which differ from the spacing of the air passage ports in the suction plate in the direction of withdrawal.

32. A device as claimed in any one of Claims 23 to 3 1 and comprising a force intensification unit provided with a suction plate, in which the effective force intensification zone is formed by a suction zone of the suction plate having a flow resistance for maintaining a pressure gradient between the end that is close to the stacker shaft bottom and the end that is remote from the stacker shaft bottom.

33. A device as claimed in claim 32, in which for varying the effective length of the suction zone at the end of the suction plate that is remote from the stacker shaft bottom, there is provided a movable member which seals the suction zone thereof against the penetration of air over an adjustable length and is actuatable in the direction of withdrawal.

34. A device as claimed in Claim 32 or Claim 33, in which for varying the effective width of the suction zone there is provided at the end of the suction plate that is remote from the stacker shaft bottom, along at least one edge strip zone thereof, a slide which seals this edge strip zone against the penetration of air over an adjustable width and which is actuatable transversely to the direction of withdrawal.

35. A device as claimed in Claim 34 and comprising two slides for sealing both edge strip zones of the suction zone in a variable width, in which both slides are actuatable simultaneously in opposite directions.

36. A device as claimed in any one of Claims 27 to 35 and comprising a withdrawal element for the leaves or the like that is designed as a belt conveyor, in which the suction plate comprises a supporting plate for the conveyor belt or conveyor belts of the belt conveyor which slide(s) over it.

37. A device as claimed in any one of Claims 27 to 36, in which the suction plate is formed by a flat upper part of a vacuum tank.

38. A device as claimed in any one of Claims 13 to 37, in which the force intensification unit can be adjusted in its height relative to the stacker shaft bottom.

39. A device as claimed in Claim 31, in which the intervals are less than the spacing.

40. A device as claimed in Claim 27, in which the entire area of the stacker shaft bottom is open.

41. A device for removing wafer-leaves, ricepaper leaves or the like from a magazine substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

42. A method for removing wafer leaves, ricepaper leaves or the like from a magazine as claimed in Claim 1 and substantially as hereinbefore described.