WEIGHT VARIATION METHOD AND SLICING MACHINE FOR ITS IMPLEMENTATION

Abstract

In order to maintain required average weight of an entire batch when slicing a loaf into slices and yet avoid underweighting individual slices, different reference weights are selected for critical areas depending on basic shape of the loaf, usually the two ends, than for the remaining area.

Claims

1. A method for at least achieving a reference weight of as many individual slices as possible when slicing a batch of loaves into slices, by automatically varying thickness for the slices to be sliced, wherein A) each loaf is arranged in a holding device for holding the loaf and advancing the loaf during slicing in a feed direction B) weight or volume of a respective loaf is determined, C) maximum number of such slices that can be produced from this loaf with at least reference weight is calculated from this, D) predetermined thickness adjustments are calculated for these individual slices of this loaf, at which actual weight of each slice should at least correspond to the reference weight and wherein E) the thickness adjustments for the individual slices of this loaf are determined in such a way that the actual weights of the individual slices are expected to reach a tolerance lower limit defined internally as a function of the reference weight, and F) the internal tolerance lower limit is set differently over the course of the loaf in the feed direction.

2. The method according to claim 1, wherein in step A) each loaf is received in a circumferentially closed forming tube as the holding device under a measuring pressure with a cross section of a cavity of the forming tube which is constant over an entire length, in step B), the weight or the volume of the respective loaf received therein is determined from a determined length and cross section of that part of the forming tube cavity which, in particular, is under the measuring pressure.

3. The method according to claim 1, wherein the internal tolerance lower limit in a middle part of the loaf as a center tolerance lower limit is set lower than a boarder tolerance lower limit in at least one of front or rear end regions of the loaf or vice versa.

4. The method according to claim 1, wherein the internal tolerance lower limit is equal to or higher than the reference weight, and/or the internal tolerance lower limit is equal to or higher than an external tolerance lower limit, which in particular is lower than the reference weight.

5. The method according to claim 1, wherein as thickness adjustments for a 1st slice or first slices of the loaf are selected either a thickness adjustment is selected corresponding to the reference weight or a thickness adjustment is selected corresponding to a length of the loaf divided by maximum number of slices with reference weight obtainable from this loaf.

6. The method according to claim 1, in which, as average over a loaf, a predetermined nominal weight and/or reference weight is to be achieved, wherein the actual weight of the previously separated slices of the loaves of the batch is determined, average weight is determined from the actual weights of all slices of the loaf already produced, and if this lies below the previous reference weight and/or the nominal weight, measures are taken for the slices still to be cut off to increase their average weight in such a way that by calculation the average weight of all slices of this loaf is expected to at least reach the reference weight and/or the nominal weight, in particular by increasing the previous reference weight and/or the previous tolerance lower limit for the rest of the slices of this loaf.

7. The method according to claim 3, wherein the boarder tolerance lower limit for the rear end region of the loaf is determined only during cutting of this loaf depending on the actual weights of the slices separated from this loaf so far, in particular during the slicing of the second half of the loaf, in particular during the slicing of the middle part of the loaf.

8. The method according to claim 1, in which, as average over the batch of loaves, the predetermined reference weight and/or nominal weight is to be achieved, wherein the actual weight of each separated slice of the loaves of the batch is determined, average weight is determined from the actual weights of all the slices already produced in a batch and, if this is below the previous reference weight and/or the nominal weight, measures are taken for the loaves still to be sliced to increase the average weight of the slices still to be sliced so that by calculation the average weight of all the slices in this batch is expected to at least reach the reference weight and/or the nominal weight, in particular by increasing the previous reference weight and/or the tolerance lower limit for the remainder of the batch.

9. The method according to claim 8, wherein the increase of the previous reference weight and/or of the tolerance lower limit is selected in such a way that this increase over the number of slices of this loaf or of this batch still to be cut off compensates for the previously accumulated shortfall weight or exceeds it by at least 1%, in particular a check as to whether this condition is mathematically expected to be complied with is checked several times during the cutting of the remaining slices, in particular after the cutting of each further slice, and in a case of a negative result of the check the increase in the previous reference weight and/or tolerance lower limit is increased in such a way that the required average weight of the slices over the entire loaf or the entire batch is mathematically expected to be achieved by the end.

10. The method according to claim 8, wherein the increase of the previous reference weight and/or the previous tolerance lower limit is chosen in such a way that this increase over the number of slices still to be cut exceeds the previously accumulated shortfall weight, but by no more than 6%, a check as to whether this condition is expected to be met mathematically is carried out several times during the cutting of the remaining slices, in particular after the cutting of each further slice, and if the result of the check is negative, the increase in the previous reference weight and/or tolerance lower limit is reduced in such a way that the required average weight of the loaf or of the batch is expected to be met mathematically by the end.

11. The method according to claim 1, wherein before slicing a first loaf of a batch of loaves, for thickness adjustments to be specified for the individual slices of this first loaf, experience values from determined thickness adjustments of previous batches are taken into account, in particular the slice adjustment of all slices for individual slice numbers corresponding to a desired reference weight and uniform over the entire loaf is increased or decreased in accordance with the actual weights thus achieved in previous batches.

12. The method according to claim 1, wherein the reference weight lies within an externally predefined tolerance range with a tolerance lower limit, wherein the external tolerance lower limit of the external tolerance range is selected as the reference weight.

13. The method according to claim 1, wherein a weight is selected as the reference weight which is a nominal weight or up to 10% above it.

14. The method according to claim 1, wherein pressed loaves of a batch allow a different number of maximum obtainable slices having the reference weight, wherein number of slices comprising front and/or rear end area is fixed, and all other slices are treated as a middle area.

15. A slicing machine for slicing loaves into slices with an actual weight of as many individual slices as possible on or above a reference weight by varying thickness adjustments for the slices to be sliced, comprising a holding device for holding a loaf to be sliced, a cutting unit for cutting slices from the loaf to be sliced, the cutting unit being controllable with respect to a thickness adjustment for parameters influencing actual weight of a slice to be cut, a scale for automatic weighing of all separated slices, a control which controls all movable components of the device, wherein the control is capable of performing the method according to claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0086] Embodiments according to the invention are shown in the following figures:

[0087] FIGS. 1a-d: a slicing machine in principle viewed from the side in different phases of slicing a loaf,

[0088] FIG. 2a, b: forming tubes in two parts in cross section in various operating states,

[0089] FIG. 3a: a pressed loaf in side view, with the slices to be made from it already sketched in,

[0090] FIG. 3b: a weight diagram over all slices of different loaves with weight adjustment relative to the reference weight,

[0091] FIG. 4a, b: diagrams internally and/or externally specified weight limits over the length of a loaf,

[0092] As FIG. 4a shows, the manufacturer of so-called fixed packages—i.e., of packaged foodstuffs with an imprinted nominal weight Gnenn, which is thus guaranteed to the purchaser—is given, on the one hand, the nominal weight Gnenn printed on the package and, on the other hand, an external tolerance lower limit TUext, as described above, usually the tolerance lower limit for individual slices.

[0093] For the control of the thickness adjustments D, it can preset itself a reference weight Gbezug to be kept, which is for example directly the nominal weight Gnenn. However, if the average of the actual weights Gist of all slices S1-Sn of a batch is only slightly below this nominal weight Gnenn, the entire batch of slices produced will be rejects.

[0094] For this reason, a slightly higher weight than the nominal weight Gnenn is often chosen as the internally selected reference weight Gbezug, in order to minimize this risk, as shown in FIG. 3b and FIG. 4a, b. This is because, as FIG. 3a shows, the nominal weight Gnenn is not sufficient to fill the batch.

[0095] As FIG. 3a shows, even a loaf L1 pressed by a longitudinal press stamp 4 against a stop plate 13 does not always fill the cavity of the forming tube 2 as desired, especially at the beginning and end. If all the slices are then cut to the mathematically correct thickness adjustment Dsoll, which theoretically should result in at least the reference weight Gbezug, the first slices S1, S2, S3 and the last slices Sn-1, Sn would still have underweight.

[0096] As can be seen from FIG. 3b, in the past such underweight initial and final slices were accepted for the first loaf L1, but based on the actual weights of its slices, the thickness adjustments D1-Dn were corrected for the initial and final slices of the subsequent loaves L2, L3 in order to achieve that their weights are as far as possible already above the selected reference weight Gbezug for the second loaf L2, but not too far above it.

[0097] However, this is a complicated calculation and the success depends on several factors which also make the calculation of the correction values difficult, such as, for example, the number of the last sliced loaves already taken into account for the calculation or also the question of whether, within a batch of basically similar loaves, there can nevertheless be outliers in shape and weight which cannot be compensated for by taking previous loaves into account, and above all the frequency of such outliers.

[0098] According to the invention, a much simpler method is proposed as shown in FIG. 4b, which is also applicable in the case of relatively strong variations in shape and size of the loaves within a batch:

[0099] In order to ensure that the weight of the critical initial and final slices of a barrel-shaped or pear-shaped loaf in the unpressed state is very likely to be at least above the external tolerance lower limit TUext, preferably above the nominal weight Gnenn or even above the reference weight Gbezug, the manufacturer sets himself an internal tolerance lower limit TUint for the weight of the slices S1, S2 . . . , on the basis of which the thickness single slices are calculated. on the basis of which the thickness adjustments D1, D2 . . . for the slice S1, S2 . . . . are to be determined, namely an internal boarder tolerance lower limit TUintR for the critical edge areas—if the same is selected for both edge areas—and an internal center tolerance lower limit TUintM for the remaining center area of slice numbers in between.

[0100] The internal center tolerance lower limit TUintM is higher than the internal center tolerance lower limit TUintR, so that even if the forming tube cavity is not completely filled in these edge areas, the probability is high that a slice whose thickness adjustment is based on this internal tolerance lower limit will actually have an actual weight which is at least above the external tolerance lower limit TUext, perhaps even above the nominal weight Gnenn or even above the reference weight Gbezug.

[0101] Since the risk of the forming tube cavity 7 not being completely filled is much less great for the center area in the case of a barrel-shaped loaf in the initial state, this internal center tolerance lower limit TUintM can be selected lower than the edge tolerance lower limit TUintR without great risk that the slices produced from this center area will be below the lowest weight threshold, the external tolerance lower limit TUext.

[0102] The internal center tolerance lower limit TUintM does not even necessarily have to be above the reference weight Gbezug and/or above the nominal weight Gnenn, but can even be just below it, as long as it is only above the external tolerance lower limit TUext.

[0103] In this way, the originally theoretically calculated number of slices that can be obtained from one loaf and that comply with the weight conditions can often be achieved.

[0104] Depending on the shape of the unpressed loaf, e.g., in the case of a strongly pear-shaped loaf, it may also be useful to set the internal boarder tolerance lower limits TUintR separately and differently for the front end and the rear end, i.e., in FIG. 4b the left and right end areas.

[0105] On the other hand, to avoid excessive overweights of the individual slices, the slice manufacturer can additionally set an internal tolerance upper limit TOintR and select the thickness adjustments in such a way that this internal tolerance upper limit TOintR is unlikely to be reached or even exceeded.

[0106] FIG. 4b also shows that the slices S1 to Sn produced by this method can have slightly lower thickness adjustments D1, D2 . . . , at least in the middle area, than slices whose calculated thickness adjustment Dsoll according to FIG. 4a is the same for all slices S1 to Sn and is selected in such a way that the total length LvL of the longitudinally pressed loaf is divided only by the maximum number Sn to be obtained of slices which have at least the reference weight Gbezug.

[0107] As a result, with the procedure according to the invention, and even if the slice thickness in the edge areas was greater than the calculated thickness adjustment Dsoll, a residual slice Srest can remain—over and above the calculated number of non-underweight slices—whose weight is below all limit values, The weight of this slice is below all limit values, presumably also below the external tolerance lower limit TUext, but can be used separately and against payment by the manufacturer of the slices, whereas if the length LvL were distributed among the individual weight-correct, attainable slices S1 to Sn of a loaf L as shown in FIG. 4a, this would represent a non-remunerated giveaway.

[0108] With regard to the slicing machine 1 shown in rudimentary form in FIGS. 1a to 1d for cutting slices S from loaves L one after the other, in particular using the method described, such a slicing machine 1 comprises on the one hand a holding device 2 for the loaf L to be sliced.

[0109] The holding device 2 is here a forming tube 2 which is circumferentially closed and open at the end faces, with a cross section of its internal space 7 which remains constant over its entire length.

[0110] Furthermore, the slicing machine 1 comprises a cutting unit 6, in which in particular a circular disc-shaped or sickle-shaped blade 3 rotating about a blade axis 3′ cuts off from the front end of the loaf L a slice S projecting from the cutting end 2a of the forming tube 2, as well as a control 1* which controls all moving parts of the slicing machine 1.

[0111] According to the invention, the control 1* is embodied to be able to perform the slicing machine 1 according to the described procedure for varying the weight of the slices S.

[0112] Preferably, the slicing machine 1 comprises, in addition to the forming tube 2, a longitudinal press stamp 4 for pressing the loaf L in the longitudinal direction 10, which can be moved from the rear open end, the loading end 2b, into the internal space 7 of the forming tube 2 with a precise fit and is attached to the front end of a piston rod 12, until the longitudinal press stamp fills the internal space 7 remaining in front of the longitudinal press stamp 4 as completely as possible and also has a cross section which is uniform over its entire length and corresponds to the cross section of the internal space 7.

[0113] Furthermore, there is usually a stop plate 13 for the loaf L pushed out of the forming tube 2 towards the front by means of the longitudinal press stamp 4, the distance A of which to the front end, the cutting end 2a of the forming tube 2, can be adjusted.

[0114] The stop plate 13 can also serve as a front stop when the loaf L is pressed longitudinally in the forming tube 2 by the longitudinal press stamp 4 when it is moved completely up to the front end face of the forming tube 2.

[0115] The blade 3, on the other hand, is usually moved back and forth at a longitudinal position that is always the same, in particular relative to the forming tube 2, in particular directly at the front end face of the forming tube 2, e.g., in a 1st transverse direction 11.1, and thus in each case cuts off a slice S from the loaf L that has in the meantime been pushed forward again as far as the stop plate 13.

[0116] As can be seen from the sequence of FIGS. 1a to 1d, before the loaf L is contacted by the cutting edge 3a of the blade 3, the cover plate 13—viewed in the longitudinal direction 10—covers the entire cross section of the forming tube 2 and, as the cutting edge 3a of the blade 3 increasingly plunges into the loaf L, moves together with the latter, e.g., in this first transverse direction 11.1 in this first transverse direction 11.1, so that the slice S pushing through the gap 17 between the cutting edge 3a and the functional edge 13a of the stop plate 13 can finally tip down over this upper edge 13a—which may or may not be bev-eled—of the stop plate 13 and fall onto the conveyor 8, as can be seen in FIGS. 1b and 1c.

[0117] The blade 3 and stop plate 13 then move back against the direction of immer-sion, i.e., in the transverse direction 11.1, as shown in FIG. 1d, and the loaf L is again pushed out over the front cutting end 2a of the forming tube 2 until it comes to rest against the stop plate 13, which is set to the desired distance A, in particular the thickness adjustment D, again covering the entire cross section of the inner forming cavity 7 as viewed in the longitudinal direction 10.

[0118] As best shown by the enlargement of FIG. 1a, stop plate 13 and blade 3, viewed in longitudinal direction 10, can overlap slightly when viewed in side view transversely to the direction of insertion 11.1, if it is ensured by corresponding slanted the edge regions facing each other that the gap 17 remaining between them is large enough for the cut-off slice S to move through the gap 17.

[0119] A slicing machine 1 of this type also has a scale 16—see FIG. 1d—which de-termines the actual weight Gist of each sliced slice S individually, and an operating unit 14—see FIG. 1a—with which, in particular, on the one hand the feed distance by which the longitudinal press stamp 4 pushes the loaf L for-wards can be set before the next slice is sliced. On the other hand, based on this, the distance A of the stop plate 13 to the axial position at which the blade 3 is located when a slice S is cut off can also be set, manually and in particular automatically by the control 1*.

[0120] The thickness adjustment D to be determined before a slice S is cut off is this feed distance, whereby the feed distance is generally not only just as large, but somewhat larger than the set distance A, but both parameters influence the subsequent weight Gist of the cut-off slice S. The slice S is then cut off at the same time.

[0121] However, the scale 16 is usually not located under the conveyor 8 onto which the separated slice S falls directly, since the vibrations caused by the impact of the fallen slice make it very difficult to determine the exact weight, but as a rule only under the further conveyor 9 immediately following it.

[0122] If technically possible, however, weighing should be carried out as far upstream as possible and immediately after the slice S has been cut off, i.e., in particular immediately after it has hit the conveyor 8, because the weight Gist of the slice S which has just been cut off should be known as early as possible in order to be able to influence the thickness adjustments D of slice S to be cut off thereaf-ter as quickly as possible.

[0123] The loaf L can be pressed not only in the longitudinal direction 10 by a longitudinal press stamp 4, but also—preferably before or at the same time—by a cross press stamp 5 in one of the transverse directions, preferably also the first transverse direction 11.1, in which the blade 3 moves during cutting.

[0124] Corresponding formations of forming tubes 2—viewed in the longitudinal direction 10—are shown in FIG. 2a, b.

[0125] The forming tube 2 viewed in the longitudinal direction 10 consists of two components in the circumferential direction, namely a transverse press rim 15 which is U-shaped in this viewing direction and into the open side of which a transverse press stamp 5 is inserted in a transverse direction, preferably the first transverse direction 11.1, and presses the previously inserted loaf L, which has an approximately elliptical cross section in the unpressed initial state, in this transverse direction 11.1 until it at least partially assumes a cross section corresponding to the cross section 7′ of the remaining internal space 7 in the forming tube 2.

[0126] The cross press stamp 5 can thereby be advanced to a fixed transverse position so that the cross section 7′ of the internal space 7 in the forming tube 2 then coincides with the front surface 4a of the longitudinal press stamp 4, which can then have a shape and size that cannot be changed.

[0127] Preferably, however, the cross press stamp 5 is force-controlled so that its final pressing position is not fixed. In this case, the longitudinal press stamp 4 must have a variable cross section in the direction of movement of the cross press stamp 5, which automatically adapts to the cross section 7′ of the momentary interior 7 of the forming tube 2.

[0128] Whereas in FIG. 2b the internal space 7 of the transverse press rim 15 has a cross section 7′ which is approximately rectangular in shape with rounded edges, in FIG. 2a the internal space 7 has a cross section 7′ which has a strongly rounded and sloping bottom compared to the lower side wall 15a of the transverse press rim 15, while the front surface of the cross press stamp 5 has an analogously opposing contour, so that this results in an oblique, approximately parallelogram-shaped or slot-shaped inner cross section 7′ with rounded edges in the closed forming tube 2.

[0129] Such a cross section 7′ of the internal space 7 comes closer to the usually elliptical initial cross section of the loaf L than a rectangular cross section and re-quires less transverse compression than with the cross section shape 7′ according to FIG. 2b, in which the width of the internal space 7 is usually selected to be smaller than the greatest extension of the approximately elliptical cross section of the unpressed loaf L.

[0130] The control 1* is signal-technically connected with the scale 16, with the operating unit 14 and likewise with the drives of all existing pressing stamps 4, 5 as well as the drives for the cutting unit 6, in particular the blade, 3, so that all movements of the slicing machine 1 can be automatically controlled by the control 1*.

REFERENCE LIST

[0131] 1 cutting machine [0132] 1* control [0133] 2 forming tube, holding device [0134] 2a cutting end [0135] 2b loading end [0136] 3 blade [0137] 3′ blade axis [0138] 3″ blade plane [0139] 3a cutting edge [0140] 4 longitudinal press stamp [0141] 5 cross press stamp [0142] 6 cutting unit [0143] 7 forming tube cavity, internal space [0144] 7′ cross section [0145] 8 conveyor [0146] 9 conveyor [0147] 10 longitudinal direction, axial direction, [0148] 10′ feed direction [0149] 11 transverse direction [0150] 11.1 first transverse direction [0151] 11.2 second transverse direction [0152] 12 piston rod [0153] 13 stop plate [0154] 13a functional edge, upper edge [0155] 14 operating unit [0156] 15 transverse press rim [0157] 16 scale [0158] 17 gap [0159] A distance [0160] D, D1-Dn thickness adjustment of individual slices [0161] Dsoll calculated thickness adjustment [0162] d slice thickness [0163] Gbezug reference weight [0164] Gist actual weight [0165] Gnenn nominal weight [0166] L, L1 to Lz loaf [0167] LvL longitudinal pressed loaf [0168] S, S1 to Sn slice [0169] TBext tolerance range [0170] TUext tolerance lower limit [0171] TBint tolerance range [0172] TUint tolerance lower limit [0173] TOint tolerance upper limit [0174] TUintM center tolerance lower limit [0175] TOintM center tolerance upper limit [0176] TUintR end tolerance lower limit [0177] TOintR end tolerance Upper Limit