阅读说明：本技术 重量改变方法以及用于执行该方法的切割机 (Weight changing method and cutting machine for performing the same ) 是由 马丁·迈尔 托马斯·沃尔克尔 于 2021-05-12 设计创作，主要内容包括：为了在将条(L)切割成切片(S)时一方面遵守整个批次的所要求的平均重量并且尽管如此仍要避免单个切片(S)的欠重,针对根据条的基本形状的临界区域、大多是两个端部,基准重量(Gbezug)被选择成不同于用于剩余的区域的基准重量。(In order to comply with the required average weight of the entire batch when cutting the strip (L) into slices (S) and nevertheless to avoid an underweight of the individual slices (S), the basis weight (Gbezug) is selected to be different from the basis weight for the remaining regions for critical regions, mostly both ends, of the basic shape of the strip.)

1. A method for producing as many individual slices (S1 to Sn) as possible at least with a reference weight (Gbezug) by automatically changing a thickness calibration (D) for the slices (S1 to Sn) to be separated, in particular when cutting a batch of strips (L1 to Lz) into slices, wherein

A) Arranging each strip (L1 to Lz) in a holding device (2) for holding the strip (e.g. Lx) and pushing it forward in a feed direction (10') during cutting,

B) ascertaining the weight or volume of the respective bar (e.g. Lx),

C) whereby the maximum number (n) of such slices (S1 to Sn) that can be produced from the strip (Lx, for example) is calculated using at least the basis weight (Gbezug),

D) calculating a predefined thickness rating (D1 to Dn) for each slice (S1 to Sn) of the strip, in which the actual weight (Gist) of each slice (S1 to Sn) is to be at least equal to the reference weight (Gbez),

it is characterized in that the preparation method is characterized in that,

E) determining the thickness calibration (D1 to Dn) for each slice (S1 to Sn) of the strip such that the actual weight (Gist) of the each slice (S1 to Sn) is predicted by calculation to reach at least one lower internal tolerance limit (TUint) determined from the basis weight (Gbezug), and

F) the lower internal tolerance limits (TUint) are different in the course of the strip (L1) in the feed direction (10').

2. The method of claim 1,

in step A), each of the strips (L1 to Lz) is received under a measurement pressure in a circumferentially closed forming tube (2) as a holding device (2) having a forming tube cavity (7) with a constant cross section (7') over the entire length,

in step B), the weight or volume of the respective strip (e.g. Lx) received therein is determined from the determined length and cross section (7') of the portion of the forming tube cavity (7), in particular at the measurement pressure.

3. The method according to any of the preceding claims,

the lower intra-pair tolerance limit (TUint) in the middle region of the strip is determined as a lower intermediate tolerance limit (TUintM) to be lower than the lower edge tolerance limit (TUintR) at the front edge region and/or the rear edge region of the strip,

or vice versa.

4. The method according to any of the preceding claims,

the inner tolerance lower limit (TUint) is equal to or higher than the basis weight (Gbezug),

and/or

The inner tolerance lower limit (TUint) is equal to or higher than the outer tolerance lower limit (TUext), which is in particular lower than the basis weight (Gboz).

5. The method according to any of the preceding claims,

as thickness calibration (D1 …) for the first slice (S1) or the first few slices (S1, S2) of the strip (L1),

selecting a thickness calibration (D1) corresponding to the reference weight (Gbezug), or

The thickness calibration (D1) is selected corresponding to the length of the strip (L1) divided by the maximum number of slices with basis weight (Gbez) that can be obtained by the strip (L1).

6. Method according to one of the preceding claims, in which a predefined nominal weight (Gnenn) and/or the basis weight (Gbezug) is to be reached on average on a strip (L1), characterized in that,

ascertaining the actual weight (Gist) of the batch, in particular of all strips (L1 to Lz), in particular of all slices (S1 to Sn) separated so far,

-finding the average weight from the actual weight (Gist) of all already produced slices of the strip (L1), -if the average weight is lower than the previous reference weight (gbezu g) and/or the nominal weight (Gnenn), taking measures for increasing the average weight of the slices yet to be cut out in such a way that the average weight of all slices of the strip (L1) is predicted by calculation to at least reach the reference weight (gbezu g) and/or the nominal weight (Gnenn), in particular by increasing the previous reference weight (gbezu g) and/or the previous lower difference limit (tunt) for the remainder of the slices of the strip (L1).

7. The method according to any of the preceding claims,

determining the lower edge tolerance limit (TUintR) for the rear end of the strip (L1) from the actual weight (Gist) of the cut piece separated from the strip (L1) so far only during cutting of the strip (L1),

in particular only during the cutting of the second half of the strip (L1),

in particular, the adaptation takes place continuously during the cutting of the intermediate region.

8. The method according to one of the preceding claims, in which the predefined basis weight (Gbezug) and/or nominal weight (Gnenn) is to be reached on average on the strips (L1-Lz) of the batch, characterized in that,

ascertaining the actual weight (Gist) of each separated slice (S1 to Sn) of the batch, in particular of all the strips (L1 to Lz),

the average weight is determined from the actual weight (Gist) of all slices already produced of the batch, and if the average weight is lower than the reference weight (Gbezug) and/or the nominal weight (Gnenn) to date, measures for increasing the average weight of the slices yet to be cut are to be taken for the strips yet to be cut, so that the average weight of all slices of the batch is at least brought to the reference weight (Gbezug) and/or the nominal weight (Gnenn) by calculation, in particular by increasing the reference weight (Gbezug) to date and/or the lower tolerance limit (TUint) for the remainder of the batch.

9. The method of claim 8,

the increase of the basis weight (Gbezug) and/or the lower tolerance limit (TUint) up to now is selected such that it compensates for the missing weight accumulated up to now or exceeds at least 1%, better at least 2%, better at least 3%,

in particular, it is checked whether the condition is complied with in a computationally predictive manner, a plurality of checks are carried out during the cutting out of the remaining slices, in particular after each further slice is cut out, and if the check result is no, the increase in the reference weight (Gbezug) and/or the lower tolerance limit (tunt) is increased to the necessary average weight of the slices over the entire strip or the entire batch up to the end in a computationally predictive manner.

10. The method according to claim 8 or 9,

the increase in the basis weight (Gbezug) and/or the lower tolerance limit (tunt) is selected so that, taking into account the number of slices yet to be cut, it exceeds the missing weight accumulated so far, but not more than 6%, preferably not more than 5%, preferably not more than 4%,

whether the condition is complied with by calculation in a predictable manner, a plurality of rechecks are carried out during the cutting out of the remaining slices, in particular after the cutting out of every other slice, and, if the result of the rechecking is negative, the increase in the reference weight (Gbezug) and/or the lower tolerance limit (TUint) up to now is reduced to the necessary average weight of the strip or the batch until the end is reached in a predictable manner.

11. The method according to any of the preceding claims,

before cutting the first strand (L1) of a batch of strands (L1 to Lz),

for the thickness calibration (D1 to Dn) to be predefined for the respective slice (S1 to Sn) of the first strip (L1), taking into account empirical values of ascertained thickness calibrations from previous batches,

in particular, the thickness calibration (D) of all slices, which is calculated to correspond to the desired basis weight (Gbezug), is increased or decreased for the number of individual slices (S1 to Sn) in a manner corresponding to the actual weight thus obtained in an earlier batch, and is uniform over the entire strip (L1).

12. The method according to one of the preceding claims, wherein the basis weight (Gbezug) lies within an externally predefined (defined) tolerance range (TBext) having a lower tolerance limit (TUext) and, if appropriate, an upper tolerance limit (TOext), characterized in that,

selecting the lower bound on the outside tolerance (TUext) of the outside tolerance range (TBext) as the basis weight (Gbezug).

13. The method according to any of the preceding claims,

selecting a weight for the base weight (Gbez) equal to or higher than the nominal weight (Gnenn) up to 10%.

14. The method according to any of the preceding claims, wherein one batch of pressed strips (L1-Lz) allows for different numbers of the most available slices with the basis weight (Gbezug), characterized in that,

determining the number of slices as leading edge region and/or trailing edge region, and

all other slices are processed as intermediate regions.

15. Cutting machine (1) for cutting a strip (L) into slices (S1 to Sn) with the actual weight (Gist) of as many individual slices (S1 to Sn) as possible reaching or being higher than a reference weight (Gbezug) by varying a thickness calibration (D) for the slices (S1 to Sn) to be cut, comprising:

holding means (2) for holding the strip (L) to be cut,

a cutting unit (6) for separating slices (S1 to Sn) from the strip (L) to be cut, wherein the cutting unit (6) is controllable with reference to the thickness calibration (D) for parameters affecting the actual weight (Gist) of the slices (S1 to Sn) to be separated,

a scale (16) for automatically weighing all separated cut pieces (S1 to Sn),

a control part (1) which controls all movable components of the device,

it is characterized in that the preparation method is characterized in that,

the control portion (1) is capable of performing a method according to any one of the preceding claims.

Technical Field

The invention relates to an improvement in weight accuracy when producing slices or portions of slices of as heavy a slice as possible by cutting slices from a largely elongate food strip, in particular a strip of fresh beef of cattle or pork, the cross section of which, however, varies more or less along the length in the original state.

Background

When producing cut pieces of exact weight and subsequently dividing into packets of nominal weight given on the packets (i.e. "fixed packets") with individual cut pieces (individual cut piece portions) -each overweight of each cut piece is a loss factor for the manufacturer, whereas when a multiple cut piece portion weight is desired to be exact, individual cut pieces that are overweight on one side and on the other side can be combined in a compensating manner to form a weight-exact portion given a predefined nominal weight, and only the overweight of the entire multiple cut piece portion, which is usually much lower in proportion, is a loss factor.

In order to be able to control the weight of the slices to be separated, the strand has a cross section that remains as constant as possible in length, mostly by pressing in a so-called forming tube that is open in the longitudinal direction and, if necessary, also in the transverse direction, mostly on the front end side and on the rear end side, but is closed in the circumferential direction.

The extruded strand is then pushed forward by means of a longitudinal extrusion die from the opposite open end side, i.e. the cutting end, of the forming tube by a defined feed path, i.e. a run-out pathThe material is usually pressed against the material holder and the cut pieces are separated directly at the front end of the forming tube by means of a cutting tool. The axial position of the tool relative to the forming tube and its front end side is usually always constant.

It should be clear here that the feed path, the so-called thickness standard, which is set automatically at the machine for each slice is usually slightly greater than the set distance between the axial positions of the holding-down frame and the knife, since the front bar piece protruding out of the forming tube extends laterally and the resulting protruding path of the bar pushed forward out of the forming tube is shorter. The actual slice thickness of the slice after its separation, i.e. after it can be freely extended, is mostly slightly greater than the set distance and slightly less than the thickness specification.

For the purposes of the present invention, a fixed correlation between the weight and the thickness of the slices and of the entire strand is assumed, and therefore the weight and the thickness of the slices are almost identical, i.e. for example the corrected weight and the corrected thickness are used almost synonymously and are therefore also often referred to as corrected values.

Before the strip is cut, the total volume of the strip located therein, which is extruded with the cut end closed, and the total weight resulting therefrom are automatically determined approximately by detecting the position of the longitudinal extrusion die and, if appropriate, of the transverse extrusion die relative to the forming tube during the application of a defined force to the extrusion dies, the force being measured, in particular by determining the length of the respective die removed from the working cylinder. The measuring force preferably corresponds to a feed force with which the strand is subsequently pushed forward out of the forming tube in steps by means of the longitudinal extrusion die for separating the cut pieces.

The theoretical thickness can be automatically calculated from the total volume of the strip and the cross section of the forming tube in the extruded state, which all slices of the strip should have, in order to produce, in particular without the remainder of the slices in the form of under-weight, only slices whose weight corresponds to at least one predefined theoretical weight, for example to a nominal weight or reference weight given on the label of the individual slices divided into small packages, which reference weight may be slightly higher than the nominal weight and which is predefined by the manufacturer of the package itself.

There are, however, a series of reasons why, although the longitudinal position of the knife is adjusted to a position corresponding to the theoretical thickness of the slice of the extruded strip, the slice nevertheless has no theoretical weight, in particular its weight is outside the tolerance range, in particular below the lower tolerance limit of said tolerance range.

Such chips with a (chip) underweight below the lower tolerance limit are defective in the production of a single chip portion of exact weight and must be used for other purposes and are therefore of low value.

When producing a multi-slice portion with an exact weight, slices whose weight is below the theoretical weight, in particular below the lower tolerance limit, can be used at least partially for combination with individual slices that are overweight within the portion.

However, it is essential according to the invention that a weight-accurate portion of individual slices is produced, i.e. slices are produced in which each individual slice is equal to a selected theoretical weight, in particular a reference weight determined by the producer of the slice, or is higher than, but as close as possible to this weight, in particular lies within the existing tolerance range, at least above the lower tolerance limit, so that defective slices are avoided.

In the case of the purchase of shares having a given nominal weight, on the basis of which the price to be offered on the packaging box is determined and the manufacturer of the packaging box is usually compensated for the share thereof, the following external, most often legal, conditions are generally applied:

condition 1:

the average of the actual weight of all produced shares of one batch (einer Charge) with the same given nominal weight must be higher than the nominal weight.

In the case of very large feeds, the cutting of which requires more than one working day, this can additionally also be applied to partial feeds cut on each individual working day.

Condition 2:

the actual weight of each individual portion, i.e. in the case of an individual slice portion of each individual slice, must be higher than an external, usually legal, lower tolerance limit TU, which is, for example, 15g lower than the nominal weight when the nominal weight is between 500g and 1000 g.

If condition 2 is violated, the corresponding share is inferior, whereas if condition 1 is violated, the entire produced feed is inferior.

Optional Producer-Inquired conditions:

as condition 3

For partial feeding, condition 1 is usually and according to the invention also to be observed, in particular within each individual strand.

The average of the actual weights of all the slices produced from one strip should therefore be higher than the nominal weight.

Here, too, the individual strips do not necessarily have to be cut in a residue-free manner according to the invention, although this is the ideal case.

Disclosure of Invention

It is therefore an object of the present invention to provide a method and a device for cutting a strip into cut pieces of exact weight, wherein ideally none of the cut pieces has an actual weight outside the tolerance range, in particular below the lower limit of the tolerance.

This object is achieved by the features of claims 1 and 15. Advantageous embodiments result from the dependent claims.

The object can be solved by the method described below when cutting, in particular, extruded, i.e. shape-defining strips which project from the described circumferentially closed forming tube having a constant cross section along its longitudinal extent, which is presupposed on a correspondingly configured cutting machine having a correspondingly configured automatic control.

The thickness calibration for the slices is automatically calculated and set by the control of the machine so that the weight of the slices corresponds to the value entered into the control.

Unless otherwise stated, the following descriptions are based on: the nominal weight given on the later package is selected for cutting instead of the higher, internally determined basis weight as basis weight and is input into the control.

In view of the fact that the method must first determine how many slices of at least the reference weight can be obtained from the strip to be cut, for which purpose the total weight and/or the total volume of the strip should first be ascertained at once, wherein each further value of the two values can be calculated from each of the two values due to the always identical specific gravity assumed at least in the case of a batch of meat pieces.

For this purpose, the strip may be simply weighed before cutting and the maximum obtainable number of slices calculated therefrom with a defined basis weight.

However, since such a strip has an irregular shape in the initial state, in particular not a constant cross section along its main extension direction, it is additionally necessary to identify the cross section at every position along the strip and to re-determine and adjust the thickness of each slice for achieving the basis weight.

To avoid this, the strip is mostly deformed in the circumferential direction at least in the longitudinal direction in a circumferentially closed forming tube, the forming tube cavity of which has a constant cross section over the entire length, for example by means of a longitudinal extrusion die, in such a way that the strip fills the inner cross section of the forming tube cavity as completely as possible at each longitudinal position and is deformed into a uniform, elongated block, i.e. continuously having a bore of the same cross section over its entire length (Kaliber). When the cross-sectional area of the forming tube cavity and thus the cross-sectional area of the elongated block is identified, only the thickness of the cut piece has to be determined in order to obtain a cut piece with a predefined weight, approximately the basis weight.

The volume of the entire bar can also be ascertained in the following manner: in the deformed state, i.e. when the deformed strip has filled the cross-section of the forming tube cavity over the entire length of the strip, it is only still necessary to ascertain the length of the strip deformed into a long block. This can be easily and automatically achieved by determining the position of the longitudinal extrusion die during the longitudinal extrusion and identifying the position of the opposing stop, which mostly rests directly against the cutting end.

The strip deformed into a long block is preferably subjected to a measured force, for example, applied to the longitudinal extrusion die, which is preferably the force that is used later to push the strip forward a defined distance beyond the front end of the forming tube during the separation of the individual cut pieces during the cutting and in particular to press the strip against a stop.

The aim is primarily to ensure that the individual slices do not become defective due to underweight on the one hand and should have, for example, as little excess weight as possible relative to the reference weight on the other hand, in order to keep as few so-called gifts as possible that are not paid for. Since the strip does not have to be cut in a residue-free manner here, each strip may leave a residual slice that is underweighed and can then be moved to another use.

However, a first condition that applies almost always must be observed here, namely that the average weight of all slices of a batch of strips, for example, must additionally also be higher than the lower tolerance limit, which can be specified by the client or legislator, usually the nominal weight, for the external world, since otherwise the entire batch is defective.

The manufacturer will therefore try to maintain this necessary average weight of all slices and at the same time try to make as few slices as possible with a weight below the lower limit of the external tolerance, thereby avoiding a single slice being inferior.

Although the latter causes relatively small losses compared to the entire batch being defective, such losses also accumulate when, for example, one or two slices in each strip become defective due to such a deficiency.

This is relatively easy to achieve without countermeasures, however, since the usually pear-shaped or salmon-shaped strip in particular in its beginning and end regions does not optimally (at least not under measured forces) match the inner contour of the forming tube cavity and also in the compressed state leaves a cavity between the already approximately oblong block-shaped strip and the forming tube, and in this case the actual weight of the slice is lower than the expected theoretical weight, for example the reference weight, assuming complete filling and a corresponding determination of the slice thickness.

When only one portion of the cut pieces is packed in a fixed package, the manufacturer of the cut pieces selects either the nominal weight (i.e. the weight of the individual cut pieces given on the finished package) as the basis weight, or a slightly higher weight for its own insurance, in order to ensure, in particular, that the average weight over the entire batch complies with the regulations.

Since according to the invention it is also possible to achieve adherence to the average weight by additional measures, it is based on the fact that the nominal weight is usually selected as the reference weight.

Starting from this known method for producing weight-accurate cut pieces, it is now attempted according to the invention to satisfy the second condition that the underweight of individual cut pieces is avoided as far as possible by determining the thickness calibration for individual cut pieces such that their weight, despite having the same internal cross section over the entire length of the forming tube, at least reaches or even exceeds the lower tolerance limit determined for the pair, which however is determined to be different in the course of the strip in the longitudinal direction.

The lower tolerance limit within such a pair, i.e. determined by the manufacturer of the slices, may be at least the basis weight that all slices should have. If the basis weight differs from a nominal weight predefined externally, this basis weight is likewise determined internally by the manufacturer of the cut pieces and therefore also has to be closely related to the nominal weight.

The basic idea is to determine different lower limits of the internal tolerance for the weight of the individual slices over the extent of the strip in its longitudinal direction, i.e. for the individual slices to be separated successively in this longitudinal direction, but in the same way for all strips of a batch, since within a batch the strips which are always similar, for example the same pieces of meat in terms of tissue (anordnung) in animals, are always the same and therefore the strips have approximately the same shape and homogeneity (Konsistenz).

Accordingly, in each case in the longitudinal direction of the strip, there is a region in which the risk is particularly great in all strips of a batch, in which the cut pieces produced with the same cut piece thickness for all cut pieces of the strip still have a weight below the lower limit of the internal tolerance.

In the barrel-shaped or pear-shaped strip in the initial state, it is the beginning or end region, i.e. the first and last slice to be separated.

In the case of bars that are closer to the spindle shape, the region can also be a slice in the middle length region of the bar, wherein the original shape of such a spindle shape must be cut more rarely to be weight-accurate.

In the generally occurring barrel-shaped or pear-shaped initial shape, there is the risk in the first two or three and in the last two or three slices that the strip does not rest completely against the inner circumference of the forming tube, as far as its end faces, but that the risk is lower in the region of the intermediate length of the strip.

In the case of a barrel-shaped and pear-shaped strip in the initial state, the lower internal tolerance limit in the region of the intermediate length, the so-called intermediate tolerance limit, is therefore lower than the lower internal tolerance limit at the beginning and end of the strip, i.e. in the edge region of the strip, so the lower internal tolerance limit in the edge region of the strip is referred to as the lower internal edge tolerance limit.

The intermediate lower tolerance limit may in particular be the basis weight or only slightly greater.

In order not to expose the two end regions of a batch of strips to the same risk, it may be important that all strips are inserted into the forming tube frontally with the same orientation for cutting, i.e. with thicker ends, for example in the case of a pear shape, since the inner tolerance lower limit may only have to be changed at one of the two end regions or differently in the two end regions relative to the middle region.

The method according to the invention provides a guarantee against excessive rejects, especially when it is not possible to ensure whether the similarity of the quality and quantity of the strips within a batch is problematic.

The relatively high lower limit of the edge tolerance at the beginning and/or end of the strip significantly reduces the risk that the cut sheet in this area also has a weight below the reference weight due to an insufficient filling of the forming tube.

Although such slices have a significantly greater risk of being overweight for this purpose, the material loss only occurs in one or two slices at the beginning and/or end of the strip, which is relatively low compared to the alternative in which defective slices are reproduced again due to underweight, in particular at the beginning and end of the strip.

Of course, the lower limit of the internal tolerance also follows the basis weight and is equal to or slightly higher than the basis weight. The lower tolerance limit for an interior pair is generally equal to or slightly higher than the lower tolerance limit predefined for an exterior pair, which is lower than the basis weight determined for the interior pair if the two differ from each other.

In the present application, slightly higher or lower in weight means that the difference with respect to the lower tolerance limit predefined to the outside is at most 5%, preferably at most 4%, preferably at most 3%, preferably at most 2%.

Since all the internally predefined weight limits are only used to satisfy, on the one hand, the externally predefined weight limits, i.e. by the client or even by the legislator, but at the same time both an overweight of the slices and in particular also an inferior slice are avoided.

Preferably, as thickness indices for the first slice or the first few slices or for the last slice or the last few slices of the strip, a thickness index is selected which is equal to the reference weight, or a thickness index which is equal to the thickness when dividing the length of the strip ascertained in the pressed state, in particular in the cut state, by the number of the maximum number of slices which can be obtained in this way.

Apart from the measures described for avoiding underweight and thus only forming defective slices, it is of course necessary to observe an average weight equal to or higher than the nominal weight, which is even more important with regard to the losses encountered.

A relatively simple method in terms of control technology is to observe the required average weight of the batch already within a partial region of the batch, in particular within each individually cut strip or cyclically (rollierrend), on only a small number of, for example, two consecutive strips, since the entire batch also satisfies the conditions when this is achieved for each partial region or strip.

A disadvantage is that, in order to comply within the bars (said conditions), the compensation scheme for complying the entire bar with said conditions may be limited, and thus the sum of all bars may add up more overweight than in the case of the condition of monitoring the average weight required in the entire batch to be cut independently of the individual bars.

In order for each strip to comply with the conditions, it is necessary first to ascertain the actual weight of all the separated slices in one go within the shortest possible time after they have been produced, preferably in real time, before they are transported away, since the thickness calibration of the remaining slices of the strip can only be controlled accordingly on the basis of the data.

For this purpose, the average weight of all cut pieces that have been cut out of the strip is determined from their actual weight, and if this average weight falls below a limit that is used as a theoretical average weight, for example a reference weight or a nominal weight, measures are taken for the thickness calibration of the cut pieces that are still to be cut out, in order to be able to achieve or even exceed a predefined theoretical average weight over all cut pieces of the strip, which is usually predefined for the entire batch of strips, for example, by calculation.

For this reason, the basis weight or the lower internal tolerance limit is usually correspondingly increased for the remainder of the cut piece of the strip to be cut out of the strip, i.e. the lower intermediate tolerance limit and/or the lower edge tolerance limit are also changed when the lower internal tolerance limit is changed.

For example, the lower edge tolerance limit for the rear end of the strip, i.e. the last cut length region, can in principle only be determined from the ascertained actual weight of the cut piece that has been separated from the strip when the strip is cut, which is most meaningful only when the second half of the strip is cut.

Preferably, the lower edge tolerance limit for the rear end of the strip can be continuously adapted during cutting so that the desired theoretical average weight is achieved over all slices of the strip.

In this case, in order to determine the lower edge tolerance limit for this rear end, the actual weight of the produced cut sheet can also be taken into account up to which cut sheet is to be cut, depending on the speed of weighing, the speed of ascertaining the actual weight of the cut sheet, the speed of ascertaining the lower tolerance limit at least for the rear edge, etc.

The intermediate lower tolerance limit also need not be of a uniform size for the intermediate region, but may even be determined to be different from one slice to the next in the intermediate region, preferably depending on the actual weight of the slices that have been produced and weighed from the strip.

A similar and identical method can be carried out not on slices of the strip but on slices of the entire batch, wherein in this case it is preferred to vary the thickness calibration of the slices to be separated for the batch depending on the ascertained average weight of the already separated slices of the batch, irrespective of whether the slices to be separated are slices from the edge region or the middle region.

For example, both the edge and intermediate lower tolerance limits are changed in the same manner for future slices and bars.

In order to provide a safety margin for the average weight to be observed (for each batch or for a partial batch or for the entire batch), the basis weight and/or the increase in the lower internal tolerance limit implemented for this purpose is determined such that, when taking into account the number of slices of the strip or batch that have yet to be cut, it is possible to compensate for the missing weight that has accumulated (aufgelaufen) and exceed at least 1%, preferably at least 2%, preferably at least 3%, depending on which entity should be considered as the average weight to be observed.

The average actual weight up to now is reviewed several times during the cutting, in particular after each further slice has been cut out, and the reference weight and/or the lower internal tolerance limit are/is changed accordingly.

If an excessively high average actual weight of the slices is ascertained for the current average actual weight, the opposite measure is likewise taken.

In order to keep the excess weight (per strip or for the entire batch) within limits, the increase in the reference weight and/or the lower internal tolerance limit implemented for this purpose is limited (deckeln) in such a way that, when the number of strips or slices of the batch that have yet to be cut is taken into account, it is possible to compensate for the missing weight that has accumulated up to now, but not more than 6%, preferably not more than 5%, preferably not more than 4%.

In order to be able to determine the thickness calibration, in particular the lower internal tolerance limit, also for the first strip of a batch in a meaningful manner, the empirical values derived from the thickness calibration and the lower internal tolerance limit of similar or homogeneous strips of a preceding batch are preferably taken into account.

The same thickness calibration over the length of the strip, calculated from the desired reference weight, of all the slices can thus be changed, i.e. increased or decreased, for the number of the individual slices in a manner corresponding to the actual weight of the slices found in the previous batch with the same or similar strip.

It should also be clear that there is typically only one lower bound on the outer tolerance range, and conversely no upper bound on the outer tolerance. However, in the case of an inner predefined weight limit, an upper internal tolerance limit is preferably determined, preferably again in respect of the middle region and the edge region, in order to thus also keep the slice within limits an undesired excess weight.

In this case, the lower limit of the external tolerance (which is lower than the nominal weight in each case for a single cut piece, since the single cut piece is completely permitted to weigh slightly below the nominal weight given on the packaging box, but not the entire batch) or a weight which is slightly above the lower limit of the external tolerance, preferably also above the nominal weight, is selected as the reference weight for reasons of safety.

It should furthermore be clear that the intermediate and edge tolerance values in the spindle-shaped bars should be reversed from what was described above for the barrel-shaped bars.

The bars of a batch may be completely different, in particular in terms of their dimensions, so that it is possible to obtain different numbers of slices from the individual bars, despite the same basis weight and/or nominal weight.

In this case, the number of slices forming the front edge region and/or the rear edge region is determined, mostly in a constant number throughout the batch, and all further slices are considered to belong to the central region and are processed in this case.

With regard to the cutting machine used for this purpose, the object of the invention is achieved with a machine as set forth in the following figures.

Drawings

The following exemplary detailed description of embodiments according to the invention. In the drawings:

figures 1a to 1d show in a schematic view a cutting machine at different stages of the cutting of the strip as seen from the side,

figures 2a and 2b show the two-piece forming tube in a transverse cross-sectional view in different operating conditions,

fig. 3a shows the extruded strip in a side view, in which the cut pieces to be produced therefrom have been marked,

figure 3b shows a weight chart for all slices of different bars when weight-matched against a reference weight,

fig. 4a, 4b show diagrams of predefined weight limits for the inner and/or outer pairs over the length of the strip. Description of the reference numerals

1 cutting machine

1 control part

2 forming tube, holding device

2a cutting end

2b loading end

3 cutting tool

3' tool axis

3' cutting tool surface

3a cutting edge

4 longitudinal extrusion die

5 transverse extrusion die

6 cutting unit

7 forming tube cavity, inner free space

7' cross section

8 conveyer

9 conveyer

10 longitudinal direction, axial direction

10' direction of feed

11 transverse direction

11.1 first transverse direction

11.2 second transverse direction

12 piston rod

13 keep off material frame

13a functional edge and upper edge

14 operating unit

15 lateral extrusion groove

16 balance

17 gap

Distance A

D. Thickness calibration of individual sections of D1-Dn

Dsoll thickness calibration by calculation

d thickness of slice

Gbezug basis weight

Actual weight of Gist

Gnenn nominal weight

L, L1 to Lz strip

Length of LvL extruded strip

S, S1 to Sn chips

TBext external tolerance range

Lower limit of external tolerance of TUext

TBint internal tolerance Range

Lower limit of internal tolerance of TUint

Upper limit of tolerance in paint

Lower limit of intermediate tolerance in TUintM pairs

Upper limit of intermediate tolerance in TOintM pairs

Lower limit of tuntr inner edge tolerance

Upper limit of tolerance of TOintR to inner edge

Detailed Description

As shown in fig. 4a, the nominal weight Gnenn printed on the packaging box is predefined on the one hand and the lower tolerance limit TUext to the outside, which is generally the lower tolerance limit for the individual cut pieces, as already mentioned, is predefined on the other hand for the manufacturer of the so-called fixed packaging (i.e. the fixed packaging of the packaged food product with the printed nominal weight Gnenn which, as it were, promises to the customer with this certainty).

For controlling the thickness D, the manufacturer can specify itself in advance the basis weight Gbezug to be adhered to, which is directly the nominal weight Gnenn, for example. Even if the average of the actual weights Gist of all the slices S1-Sn of a batch is only slightly lower than the nominal weight Gnenn, the produced slices of the entire batch are inferior.

A weight slightly higher than the nominal weight Gnenn is therefore usually chosen as the basis weight gbezu chosen within the pair in order to minimize the above-mentioned risk, as shown in fig. 3b and fig. 4a, 4 b.

Since, as shown in fig. 3a, the strand L1 which is extruded in this case by the longitudinal extrusion die 4 toward the material stop stack 13 does not always fill the cavity of the forming tube 2 as desired, just at the beginning and end. In this case, if all slices are cut with the correct thickness calibration Dsoll (which theoretically should result in at least the basis weight Gbezug) by calculation, the first slices S1, S2, S3 and the last slices Sn1, Sn may be underweighted.

As can be seen from fig. 3b, such underweighed start and end slices of the first strip L1 have been accepted in the past, but the thickness indices D1-Dn have been corrected for start and end slices of the subsequent strips L2, L3 on the basis of the actual weight of their slices, so that their weight is already as high as possible at the second strip L2, but not too much, above the selected reference weight gbezu g.

However, this is complicated to calculate and the success or failure depends on various factors which in turn make the calculation of the correction value difficult, such as the number of last strips cut which have already been considered for the calculation, or for example the following problems: i.e. whether substantially similar bars within a batch may have outliers in shape and weight that cannot be compensated by considering previous bars, and in particular the frequency of such outliers.

According to the invention, a much simpler method is proposed according to fig. 4b, which can be applied even in the case of large fluctuations in the shape and size of the bars within a batch:

in order to ensure that the barrel-shaped or pear-shaped strip in the uncompressed state and the critical beginning and end slices in the compressed state are at least as high as possible in terms of weight above the outer tolerance lower limit TUext, preferably at the nominal weight gnen or even at the basis weight gbezu, the manufacturer prescribes itself a tolerance lower limit tunt in the pair of weights for the slices S1, S2 …, from which the thickness calibration D1, D2 … for the slices S1, S2 … is to be determined, more precisely, on the one hand, when the same selection is made for both edge regions, the inner edge tolerance lower limit tuntr is determined for the critical edge region and, similarly, on the other hand, the inner intermediate tolerance lower limit tuntm is determined in terms of the number of slices for the remaining intermediate regions in between.

Here, the inner-pair lower tolerance limit tuntr is higher than the inner-pair lower intermediate tolerance limit tuninm, so that it is very likely to be achieved in said edge region even without completely filling the forming tube cavity, the cut piece (whose thickness calibration has followed the inner-pair lower tolerance limit) actually having an actual weight which is at least higher than the outer-pair lower tolerance limit TUext, possibly even higher than the nominal weight Gnenn or even higher than the reference weight gbezu.

Since the risk of an incompletely filled forming tube cavity 7 is not so great for the intermediate region as a barrel-shaped strip in the initial state, the inner intermediate tolerance lower limit tuninm may be chosen to be lower than the edge tolerance lower limit tuninr without causing a significant risk of the slices made from the intermediate region being below the lowest weight threshold, i.e. the outer tolerance lower limit TUext.

Here, the inner intermediate tolerance lower limit tuntm does not even have to be higher than the basis weight Gbezug and/or the nominal weight Gnenn, but may even be slightly lower than the basis weight Gbezug and/or the nominal weight Gnenn, as long as the inner intermediate tolerance lower limit is higher than the outer tolerance lower limit TUex.

This generally allows the number of slices to be initially calculated theoretically, which can be realized from a single strip, subject to the weight conditions.

Depending on the shape of the non-compressed strip, it may also be expedient, for example in the case of a pronounced (stark) pear shape, to determine the inner edge tolerance lower limit tuntr in a separate and different manner for the front end and the rear end, i.e. the edge regions on the left and right in fig. 4 b.

On the other hand, to avoid excessive overweight of the individual slices, the producer of the slices may additionally set an upper intra-tolerance value tontr, and the thickness calibration is chosen to be expected not to reach or even not to exceed said upper intra-tolerance value tontr.

Fig. 4b also shows that the cut sheets S1 to Sn produced according to the method can have slightly smaller thickness indices D1, D2 … at least in the central region than the cut sheets whose calculated thickness index Dsoll is identical according to fig. 4a for all cut sheets S1 to Sn and is selected such that the entire length LvL of the extruded strand is divided only by the maximum resulting number Sn of the cut sheets having at least the reference weight gbezu g.

Thus, in the method according to the invention and even when the slice thickness in the edge region is greater than the calculated thickness specification Dsoll, the computationally ascertained number of slices exceeding the non-underweighed can leave a remaining slice Srest whose weight is below all limits and is expected to be below the lower tolerance limit TUext, which can however be used alone by the manufacturer of the slices and evaluated for costs, while according to fig. 4a when the length LvL of the bar L is assigned to the respective weight-correct, realizable slices S1 to Sn, this may represent a gratuitous gift.

Referring to a cutting machine 1, which is not shown in any way in fig. 1a to 1d, in particular for cutting out the slices S from the strip L in sequence when the described method is applied, such a cutting machine 1 comprises, on the one hand, a holding device 2 for the strip L to be cut.

The holding device 2 is a circumferentially closed and open-ended forming tube 2 which has a cross section of its inner free space 7 which remains constant over its entire length.

The cutting machine 1 further comprises a cutting unit 6 in which there is provided, in particular, a disc-shaped or sickle-shaped cutter 3 rotating about a cutter axis 3', which separates a cut piece S protruding from the cutting end 2a of the forming tube 2 from the front end of the strip L, and the cutting machine 1 further comprises a control part 1 which controls all the movable parts of the cutting machine 1.

According to the invention, the control 1 is configured so as to be able to operate the cutting machine 1 according to the described method for varying the weight of the slices S.

Preferably, cutting machine 1 comprises, in addition to forming tube 2, a longitudinal extrusion die 4 which is fixed at the front end of piston rod 12 and which can be moved in a fittingly accurate manner into its inner free space 7 from the rear open end, i.e. loading end 2b, for extruding strip L in longitudinal direction 10 until it fills the inner space 7 remaining before longitudinal extrusion die 4 as completely as possible and the cross section corresponding to inner space 7 has the same cross section over its entire length.

Furthermore, a material stop 13 is usually provided for pushing the strand L of the forming tube 2 forward by means of the longitudinal extrusion die 4, the distance a of which from the front end of the forming tube 2, i.e. the cutting end 2a, can be adjusted.

The material retaining frame 13, in a state of being completely moved to the front end face of the forming tube 2, may also serve as a front stopper when the strip L is longitudinally extruded in the forming tube 2 by the longitudinal extrusion die 4.

In contrast, the knife 3 is moved back and forth, for example in the first transverse direction 11.1, in particular at the same longitudinal position relative to the forming tube 2, in particular directly at the front end face of the forming tube 2, and thus always separates a slice S from the strip L which is pushed forward again during this time to the holding frame 13.

As can be seen from the sequence of fig. 1a to 1d, before the cutting edge 3a of the knife 3 contacts the strip L, the stock stop 13 covers the entire cross section of the forming tube 2, viewed in the longitudinal direction 10, and moves together with the cutting edge 3a of the knife 3 as it gradually penetrates into the strip L, for example in the first transverse direction 11.1, so that the cut pieces S cut here through the gap 17 between the cutting edge 3a and the functional edge 13a of the stock stop 13 can finally tip over downwards via the upper edge 13a (which may be inclined or not) of the stock stop 13 and fall onto the conveyor 8, as can be seen in fig. 1b and 1 c.

Next, as shown in fig. 1D, the tool 3 and the material stop 13 are moved back counter to the insertion direction, i.e. in the transverse direction 11.1, and the strand L is pushed out again beyond the front cutting end 2a of the forming tube 2 until it abuts against the material stop 13, which is adjusted to the desired distance a, in particular the thickness dimension D, and again, the entire cross section covering the inner forming cavity 7 is viewed in the longitudinal direction 10.

As is best shown in the enlarged illustration in fig. 1a, the material stop 13 and the tool 3, viewed in side view transversely to the insertion direction 11.1, can slightly overlap, viewed in the longitudinal direction 10, and it is ensured by corresponding inclined portions in the edge regions facing one another that the gap 17 remaining therebetween is sufficiently large that the separated cut pieces S can move through the gap 17.

This cutting machine 1 also has a scale 16 (see fig. 1d) which ascertains the actual weight Gist of each separated section S individually, and this cutting machine 1 also has an operating unit 14 (see fig. 1a) with which, in particular, on the one hand, the feed path of the longitudinal extrusion die 4 for pushing the strand L forward can be adjusted before separating the next section. On the other hand, the distance a of the material holder 13 from the axial position of the tool 3 during the slicing S can also be adjusted manually and in particular automatically by the control unit 1.

The thickness calibration D to be determined before the separation of the slices S is the feed path, wherein the feed path cannot in each case be exactly as large as the adjusted distance a, but is slightly larger than the adjusted distance a, however the two parameters influence the subsequent weight Gist of the separated slices S.

However, since it is difficult to determine an accurate weight due to the shock caused by the collision of the dropped slices, the scale 16 is mostly located not below the conveyor 8 onto which the separated slice S is directly dropped but generally only below the other conveyor 9 immediately following it.

If this is technically possible, the weighing should be carried out as upstream as possible and directly after the separation of the slices S, i.e. in particular directly after the impact on the conveyor 8, since the weight Gist of the just separated slices S should be known as early as possible, so that the thickness calibration D to be separated later can be influenced as quickly as possible in accordance therewith.

The strip L can be extruded not only by the longitudinal extrusion die 4 in the longitudinal direction 10, but also preferably in advance or simultaneously by the transverse extrusion die 5 in one of the transverse directions, preferably also in the first transverse direction 11.1 along which the knife 3 moves during the separation.

Fig. 2a, 2b show the respective configuration of the forming tube 2, viewed in the longitudinal direction 10:

the forming tube 2, viewed in the longitudinal direction 10, is composed of two components in the circumferential direction, namely a transverse extrusion groove 15 which is U-shaped in the viewing direction, the transverse extrusion die 5 is moved in a matched manner in the transverse direction, preferably in a first transverse direction 11.1, into the open side of the transverse extrusion groove, and the previously inserted strip L, which has a substantially oval cross section in the non-extruded initial state, is extruded in the transverse direction 11.1 until it at least partially develops a cross section in the forming tube 2 which corresponds to the cross section 7' of the remaining inner free space 7.

The transverse extrusion die 5 can be advanced here to a fixed transverse position, so that the cross section 7' of the inner free space 7 in the forming tube 2 is in this case identical to the front surface 4a of the longitudinal extrusion die 4, which can have a non-variable shape and size.

Preferably, however, the lateral extrusion die 5 is force-controlled, so that the final extrusion position of the lateral extrusion die is not fixed. In this case, the longitudinal extrusion die 4 must have a variable cross section in the direction of movement of the transverse extrusion die 5, which automatically matches the cross section 7' of the temporary interior 7 of the forming tube 2.

In fig. 2b, the inner free space 7 of the lateral pressing channel 15 has a substantially rectangular cross section 7' with rounded edges, while in fig. 2a the cross section 7' of the inner free space 7 has a largely rounded and inclined base relative to the deeper, downward side walls 15a of the lateral pressing channel 15, while at the same time the front surface of the lateral pressing die 5 has a similarly opposite contour, so that this results in an inclined, substantially parallelogram-shaped or slot-shaped inner cross section 7' with rounded edges in the closed forming tube 2.

Such a cross section 7 'of the inner space 7, in which the width of the inner free space 7 is mostly selected to be smaller than the maximum length of the substantially elliptical cross section of the non-compressed strip L, is closer to the largely elliptical initial cross section of the strip L than the rectangular cross section and requires less lateral compression than in the case of the cross-sectional shape 7' according to fig. 2 b.

The control unit 1 is connected to the scale 16 and the operating elements 14, as well as to the drives of all the extrusion dies 4, 5 present and to the drives for the cutting units 6, in particular the knives 3, by means of signal technology, so that the entire movement of the cutting machine 1 can be automatically controlled by the control unit 1.