System and method for cutting products

Abstract

System for cutting products, for example potatoes, comprising: -a cutting device (4), provided with at least one knife (4a); and - liquid supply means, arranged to supply the products (P) in a liquid stream to the at least one knife (4a) of the cutting device (4), such that the products (P) under influence of fluid pressure are cut by the at least one knife of cutting device (4); wherein the system comprises at least one detector (7, 8, 9), configured to monitor a cutting process carried out by the knife (4a), and issue a respective measuring signal (S), wherein the system comprises a data processor (10) which is arranged to process the measuring signal (S) issued by the detector (7, 8, 9), and to: -1a) automatically adjust at least one parameter of the cutting process, depending on the measuring signal (S); and / or -1b) issue a disturbance signal if it follows from the measuring signal (S) that the cutting process is subject to a determined disturbance.

Description

[0001] Title: System and method for cutting products

[0002] The invention relates to a system for cutting products, for example, potatoes. In addition, the invention provides a method for cutting products.

[0003] Systems to cut products are known in diverse variants. The system usually includes a cutting device, provided with one or more knives, for carrying out a cutting process. According to an advantageous implementation, liquid supply means are used to supply the products in a liquid stream (in particular a water stream) to the at least one knife, such that the products under the influence of fluid pressure are cut by the at least one knife of the cutting device.

[0004] The products to be cut may, for instance, comprise cuttable food products, for example, potatoes or other edible bulbous or tuberous products, vegetable products or fruit products. Preferably, the products are each cut into separate product parts (e.g., slices, or elongate parts) for the purpose of further processing.

[0005] In practice, it appears that the knife gets dull with the lapse of time. As a result, the quality of cut product may deteriorate. The product may, for instance, obtain an unwanted shape, as with breakage of the cut product and product fragments. Also, the orientation of the product with respect to the cutting direction may be wrong. Further, the product may be damaged in a less visible manner, for instance, having damage such as small cracks and greater roughness. In a follow-up process, this may give rise to more breakage of the product, and, for example, a greater absorption of liquid (e.g., frying oil if a frying process is to be carried out). In the known process, therefore, the knife is periodically replaced with a new (sharp) knife.

[0006] A disadvantage of the known system is that replacing the knife can be time consuming. Also, in many cases, it is found that a knife taken away from a cutting process is still sufficiently sharp. On the other hand, the known process, in some cases, appears to yield product parts of relatively poor quality.

[0007] US5421226 describes a hydraulic cutter, provided with means for detecting normal pressure transients and for detecting above-normal pressure transients, and a method of stopping the flow of liquid and food product upon detection of the occurrence of an above-normal pressure transient in the liquid.

[0008] US5904083 concerns a system provided with a knives fixture including a detector system, to detect a broken knife (so that the production line upon knife breakage can be halted immediately).

[0009] The present invention contemplates elimination, or at least reduction, of above-mentioned disadvantages of the known system. In particular, the invention contemplates provision of a system that can cut the products reliably and efficiently, such that product parts (i.e. , cut product) of good quality can be produced.

[0010] To that end, according to an aspect of the invention, the system is characterized by the features of claim 1.

[0011] The system for cutting products comprises advantageously:

[0012] -a cutting device, provided with at least one knife; and

[0013] -liquid supply means, arranged to supply the products in a liquid stream to the at least one knife of the cutting device, such that the products under influence of fluid pressure are cut by the at least one knife of the cutting device; wherein the system is provided with at least one detector, configured to monitor a cutting process carried out by the knife and to issue a respective measuring signal, wherein the system comprises a data processor which is arranged to process the measuring signal issued by the detector, and to:

[0014] -la) automatically adjust at least one parameter of the cutting process, depending on the measuring signal; and / or -lb) issue a disturbance signal if it follows from the measuring signal that the cutting process is subject to a determined disturbance.

[0015] In this manner, the system can detect a problem with the cutting device in a timely manner, and automatically undertake a suitable action after detection of such a problem. In this manner, the system’s delivering product parts of reduced quality can be prevented, or the chance thereof can be considerably reduced. The measuring signal mentioned can comprise various cutting device-related parameters (e.g., concerning a sharpness of the at least one knife), which is further explained hereinbelow.

[0016] Further, an aspect of the invention provides a method, for cutting products, for example potatoes, for instance utilizing a system according to the invention, the method comprising:

[0017] -supplying the products under fluid pressure to at least one knife of a cutting device, such that the products under influence of the fluid pressure are cut by the at least one knife of the cutting device;

[0018] -discharging and / or collecting the cut products;

[0019] -monitoring the cutting process carried out by the at least one knife, with issuance of a respective measuring signal which is processed by a data processor; and:

[0020] -la) depending on the measuring signal, automatically adjusting at least one parameter of the cutting process; and / or

[0021] -lb) generating a disturbance signal if it follows from the measuring signal that the cutting process is subject to a determined disturbance.

[0022] In this manner, above-mentioned advantages can be achieved.

[0023] Further, especially advantageous elaborations of the invention are described in the dependent claims. The invention will now be further explained on the basis of an exemplary embodiment and the drawing. In the drawing: Figure 1 schematically shows an example of a system for cutting products, known from the prior art;

[0024] Figure 2 schematically shows a first exemplary embodiment of the invention;

[0025] Figure 3 shows a first example of a detection signal of the system shown in Fig. 2;

[0026] Figure 4 shows a second example of a detection signal of the system shown in Fig. 2;

[0027] Figure 5 schematically shows a second exemplary embodiment of the invention;

[0028] Figure 6 schematically shows a further elaboration of a sorting system;

[0029] Figure 7 shows a detector signal course and signal slope course of a pulse concerning a correct product cutting;

[0030] Figure 8 shows a detector signal course of a double product cutting;

[0031] Figure 9 shows a detector signal course and signal slope course concerning a knife block stoppage;

[0032] Figure 10 shows a detector signal course and signal slope course concerning a product cutting by a soiled knife block; and

[0033] Figure 11 shows a detector signal course and signal slope course concerning cutting by a blunt knife block.

[0034] Like or corresponding features are indicated in this patent application with like or corresponding reference signs.

[0035] In Figure 1 an example of a system, known per se, for cutting products P is shown. The products P may, for instance, be (uncut) potatoes, but this is not requisite.

[0036] The system has at least a cutting device 4, provided with at least one knife 4a (e.g., made of steel).

[0037] The at least one knife 4a may, for instance, be part of a knife block which is provided with a number of knives or knife sections (e.g., a knife grid, or an assembly of knives) and is arranged to cut each supplied product P into parts in a particular pattern. Such a knife block may, for instance, be provided with an array of parallel disposed knives, to cut supplied products P each into thin product slices. In an alternative implementation, such a knife block may be provided with knife sections disposed at right angles to each other (in particular, a knife grid), to cut supplied products each into parts of angular cross section, for example, a square or rectangular cross section (for instance, to cut potatoes into fries). In other words: the at least one knife part 4a is preferably part of a knife cutting block, comprising at least one array of mutually equidistantly arranged knife parts, which define, for example, rectangular knife passages.

[0038] Further, liquid supply means 3, 50 are provided, arranged to supply the products P in a liquid stream to the at least one knife 4a of the cutting device 4, such that the products P, under influence of fluid pressure, are cut by the at least one knife 4a of cutting device 4 (i.e., the liquid supply means 3, 50 are arranged to force product P with a liquid stream against the at least one knife of the cutting device to cut the product). Preferably, water is used as a transport liquid by the liquid supply means. The at least one knife 4a is, in particular, disposed parallel to a local conveying direction of the liquid stream, with a sharp knife edge on an upstream knife position for reception - and cutting - of products P supplied thereto, which will be clear to the skilled person.

[0039] Such a (water-)cutting system may, for instance, be provided with a tank 1 which is filled with the transport liquid W (in particular, water). The tank 1 is preferably connected to a pump 3 to supply the contents of the tank 1 (i.e., liquid W with product P) to a liquid channel 50, for example a transport tube.

[0040] Optionally, a product stream aligning system 6, known per se, may be provided, upstream of the cutting device 4. The aligning system 6 is preferably configured to have the products P, supplied via the liquid W, reaching the cutting device 4 one by one. Preferably, the product stream aligning system 6 is configured to bring the products P, supplied via the liquid W, each into an orientation desired for the cutting device 4. Preferably, to that end, the product aligning system 6 furnishes a narrowing 50b of the liquid channel 50, between an upstream part 50a and a downstream part 50c of the liquid channel 50. A diameter of the upstream part 50a of the liquid channel 50 may, for instance, be equal to or greater than twice a maximum outer dimension (e.g., diameter or cross section) of supplied products P. A diameter of the downstream part 50c of the liquid channel 50 (which is connected to the cutting device 4) may, for instance, be somewhat greater than, equal to, or less than, a maximum outer dimension (e.g., diameter or cross section) of supplied products P.

[0041] During use of the system shown in Fig. 1, uncut products P can be fed to the pump tank 1 (as indicated with arrow B), by a product supply system not shown (known per se). The products P are each, with liquid W, supplied by pump 3 to the cutting device 4 placed downstream, via the aligning system 6, and pressed against the at least one knife 4a. The cut product Q may thereupon be separated from the liquid W, for instance with a separation system 5, known per se (e.g., a dewatering belt). The cut product Q may then be carried off for further processing (e.g., drying, a frying process, packaging, transport and / or the like), and the separated liquid W can, for instance, be treated (e.g., filtered) for reuse in the system.

[0042] Preferably, the complete process, from the liquid channel 50 up to and including the cutting device 4, and preferably also up to and including the separating system 5, is completely enclosed. This makes it difficult to monitor and optimize the cutting process.

[0043] In practice, it has been found that the condition of the cutting device 4 deteriorates during cutting. The cutting device 4 of the known system must therefore be regularly replaced, but it is usually not clear when, exactly, the cutting device 4 has to be replaced. Thus, it is possible that the cutting device 4 is replaced too soon (i.e., when the functioning of the cutting device is still acceptable). And it is also possible that the cutting device 4 is replaced too late (the functioning of the cutting device then has already been unacceptable for some period of time). Exchange of the cutting device 4 may, besides the costs of exchange, also cause a brief decrease of the quality of the cut product. Further, with the known system, it is necessary to halt the production line for exchanging the cutting device 4.

[0044] Figure 2 shows schematically an example of an especially advantageous system for cutting products P, with which the above- mentioned problems can be counteracted. The system differs from the system shown in Fig. 1 in that it is provided with at least one detector 7, 8, 9, configured to monitor a cutting process carried out by the knife 4a and to issue a respective measuring signal S (see Figs. 3, 4). Moreover, the system is provided with a data processor 10, which is arranged to process the measuring signal S issued by the detector 7, 8, 9, and to carry out at least one of the following steps:

[0045] -a) automatically adjusting at least one parameter of the cutting process, depending on the measuring signal S mentioned; and

[0046] -b) issuing a disturbance signal if it follows from the measuring signal S that the cutting process is subject to a determined disturbance.

[0047] The data processor 10 can be implemented in different manners, and can comprise, for example, a computer, digital data processor, server, and / or the like. The data processor 10 can comprise software, which provides data processor functionality during execution of the software by suitable electronic hardware. The data processor 10 can be coupled to the at least one detector 7, 8, 9 in different manners, for reception of a measuring signal S, or information concerning the measuring signal, for instance, via one or more wired and / or wireless communication connections 60, 61, 62 (shown schematically). The data processor 10 may, for instance, be part of, or be integrated with, a control system for control of the cutting device. According to a further elaboration, the data processor 10 may be directly or indirectly coupled to the pump 3, in particular for the purpose of regulating a pump speed of the pump 3, and / or activating and deactivating the pump 3. According to a further elaboration, the data processor 10 may, for instance, be arranged to automatically switch the pump 3 off, depending on a result of the measuring signal S issued by the detector 7, 8, 9. In that case, step la) comprises (preferably temporarily) stopping supply of products to the at least one knife of the cutting device.

[0048] It follows that the data processor 10 is preferably arranged to cooperate with the liquid supply means of the system, for the purpose of temporarily interrupting supply of products P to the cutting device 4, depending on a result of the processing of the measuring signal S issued by the detector 7, 8, 9.

[0049] After the product supply has been stopped (or, alternatively, during product supply), the at least one knife 4a is preferably replaced with a respective new (sharp) knife. This knife replacement is preferably carried out automatically by the system, hence without human intervention. To that end, the system is preferably provided with a knife takeaway device 11, arranged for automatically removing the at least one knife 4a from the liquid supply means. In that case, the data processor 10 is preferably implemented to cooperate with the knife takeaway device 11, to automatically remove the at least one knife 4a, depending on the measuring signal S issued by the detector 7, 8, 9. The knife takeaway device 11 is preferably arranged to automatically supply at least a second knife 4b to the liquid supply means for replacement of a knife 4a removed by the knife takeaway device (such that the at least second knife 4b can thereupon cut products P supplied via the liquid stream). The knife takeaway device 11 is, in particular, provided with a knife holder Ila displaceable between at least two positions, which holds both the first knife (or knives) 4a and the second knife (or knives) 4b. In a first position of the knife holder Ila (shown in Figure 2), the at least one first knife 4a is placed in the liquid stream for reception of the products P to be cut, whereas the at least one second knife 4b is positioned outside that liquid stream. In a second position of the knife holder Ila (shown in Figure 2), the at least one first knife 4a is placed outside the liquid stream (for instance for replacement, removal, a sharpening of the knife and / or the like), whereas the at least one second knife 4b is positioned in that liquid stream for the purpose of reception and cutting of products P. Preferably, knife takeaway device 11 is provided with a drive 11b, for example, a motor, piston / cylinder assembly, pneumatic drive and / or the like, which drive 1 lb is implemented to bring about an above- mentioned displacement of the knife holder Ila. It is noted that such a knife exchange device is in itself known from practice, in the form of a knife block exchange system (where a first knife block, which is provided with a knives grid, can be replaced with a second knife block). According to a further elaboration, the drive 1 lb of the knife takeaway device 11 is controllable by the data processor 10.

[0050] An above-mentioned disturbance of the cutting process may, for instance, comprise a stoppage of a part of the liquid supply means, and / or a blockage of the at least one knife of the cutting device, and / or a determined bluntness of the at least one knife 4a. The cutting device may, for instance, plug wholly or partly due to product or unwanted material.

[0051] The at least one knife of the cutting device may, moreover, be subject to wear and damages, for instance, caused by the product and unwanted material. The wear and damages can manifest themselves as blunt, bent, torn or rough knives. Clinging unwanted material, moreover, can be the cause of the roughening of the knives.

[0052] Such disturbance and / or wear of the at least one knife may, for instance, be automatically detected by an above-mentioned detector 7, 8, 9, and, in particular, by suitable data processing of the detector signal S by the data processor 10, which will be explained hereinbelow.

[0053] The data processor 10 may, for instance, be provided with a disturbance signal generator 10a, or be coupled therewith, for the purpose of furnishing a disturbance signal. Such a disturbance signal generator 10a can optionally comprise, for example, one or more of a user interface, display, loudspeaker, light source, and / or the like.

[0054] An above-mentioned detector can be a flow meter 7 (e.g., disposed after the pump 3), arranged to measure a liquid flow through the transport channel 50 and to issue an above-mentioned measuring signal S concerning that flow, for the purpose of monitoring the cutting process. According to a further elaboration, a flow (rate) measured by the flow meter 7 can be converted to a product-cutting velocity in the cutting device 4. A decreasing liquid flow can, in particular, be proportional to a decrease of product cutting velocity. In particular, the data processor 10 can be arranged to compare a measured liquid flow with a liquid flow threshold value, and to carry out an above-mentioned step la) and / or step lb) if an instantaneous measured liquid flow deviates in a predetermined manner (for instance, by a predetermined percentage) from the liquid flow threshold value.

[0055] An above-mentioned detector can be a manometer 8, arranged to measure a fluid pressure in the transport channel 50 and to issue an above- mentioned measuring signal S concerning that pressure, for the purpose of monitoring a cutting process. According to a further elaboration, a fluid pressure measured by the manometer 8 can, for instance, be converted by the data processor 10 to a cutting velocity in the cutting device 4. An increasing fluid pressure can, at constant pumping power, be, in particular, proportional to a decrease of product-cutting velocity. In particular, the data processor 10 may be arranged to compare a measured fluid pressure with a threshold value, and to carry out an above-mentioned step la) and / or step lb) if an instantaneously measured fluid pressure deviates in a predetermined manner (for instance, by a predetermined percentage) from the fluid pressure threshold value.

[0056] An above-mentioned detector 9 may, for instance, be arranged to measure a force F (e.g., impulse or impact) exerted on the cutting device 4 and to base the measuring signal S on that force, and issue it, for the purpose of monitoring the cutting process. According to a further elaboration, the force exerted on the cutting device 4 (to be measured by the detector 9) has at least a force component directed parallel to the local liquid flow. The force detector 9 may, for instance, be part of the cutting device 4, or be (mechanically) coupled to the cutting device. Such a detector 9 may, for instance, be arranged to record a course of force F(t) in time t (a respective signal course F(t) in time, i.e., force F as a function of time t, is represented in Figures 3, 4). The force detector 9 can comprise one or more load cells, acceleration sensors, vibration sensors and / or acoustic sensors, arranged to detect each cutting action of the cutting device 4. In particular, the at least one knife 4a will undergo an impulse (and respective impact) during reception of a supplied product P. Such a mechanical interaction between the product P and the knife 4a is transmitted to other components of the cutting device (e.g., a knife suspension, a frame, housing and / or the like), and may thus be detected by the force detector 9 (e.g., by detection of a mechanical force, tension, vibration, acceleration, acoustic signal, and / or the like, associated with that mechanical interaction) which will be clear to the skilled person. A force detector 9 may thus be arranged at different locations of, or near, the cutting device, for instance at or near the at least one knife 4a itself, and / or be part of, or be coupled to, a knife suspension, a frame, housing or other component of the cutting device 4. According to a further elaboration, at least a part of the cutting device 4 may be disposed to be slightly displaceable, against a spring force (of spring means), whereby a product impact on the at least one knife 4a (during supply of the product P to that knife 4a) leads to a displacement of the displaceable part of the cutting device 4. In that case, the above-mentioned force detector 9 may be arranged to measure that displacement of the displaceable part of the cutting device 4.

[0057] According to a further elaboration, the detector 7, 8, 9 is implemented such that at least a part 22, 22a of the respective measuring signal S is proportional to a sharpness of the at least one knife 4a, while the detector 7, 8, 9 is, for instance, configured to generate a measuring signal S associated with a cutting force produced by the knife 4a and / or a measuring signal associated with a fluid pressure exerted on the products P.

[0058] According to a further elaboration, the data processor 10 is implemented to process the measuring signal S issued by the detector 7, 8, 9, such that individual product cutting passes, in particular respective signal pulses 22, 22a, are detected in the measuring signal S by the data processor 10, and, for instance, may be compared by the data processor 10 with a cutting pass threshold value DI (see Fig. 3). Preferably, the data processor 10 is configured to carry out one or more of above-mentioned steps la) and lb) when the data processor 10 determines that the measuring signal S has reached the cutting pass threshold value DI.

[0059] According to a further elaboration, the data processor 10 is implemented to process the measuring signal S issued by the detector 7, 8, 9, such that passive periods of the cutting device between individual product cutting passes are detected in the measuring signal S, and, for instance, may be compared by the data processor 10 with a (predetermined) passive period threshold value D2 (of the signal)(see Fig. 4). Preferably, the data processor 10 is arranged to carry out one or more of above-mentioned steps la) and lb) when the data processor 10 determines that the measuring signal S has reached the passive period threshold value D2. The comparison with a passive period threshold value D2 (and defining such a passive period threshold value D2) provides a reliable manner to detect problems with the knife block. Figures 3 and 4 show examples of measuring signals S, S’ possibly issued by an above-mentioned force detector 9.

[0060] As follows from Figure 3, the force signal can comprise a series of pulses 22 concerning individual cutting passes of the cutting device (each pulse concerns the cutting of a single product P). Between the pulses 22, the force signal can comprise an intervening period 21 (an above-mentioned passive period), in which the cutting device experiences a relatively low force.

[0061] With the lapse of time, the at least one knife can exhibit bluntness, which entails increase of the cutting force pulse. This is denoted with pulses 22a. When the data processor 10 determines that the force pulse 22a reaches a predetermined force threshold value DI, the data processor 10 can automatically take action, and carry out one or both of steps la) and lb).

[0062] Figure 4 shows that a disturbance can occur, for example, a blockade of a part of the at least one knife, or the like, which may be accompanied by a short relatively high pulse 23 in the detector signal S. As a result of such a disturbance, a persistent increase can arise in the signal part concerning the passive periods between individual product cutting passes, which is denoted with 21a in Fig. 4. The data processor 10 can automatically carry out one or more of the steps la) and lb) when the data processor 10 determines that the passive period signal part reaches the respective threshold value D2.

[0063] In particular, there is represented in Figures 3 and 4, in a schematic and simplified manner, a course of force with respect to time t as measured by force detector 9. Here, there is represented, inter alia, the force exerted by the liquid stream, and a course of force exerted by the partial product passing through the cutting device. This course of force can also be called a pulse. The following information, for example, can be derived from the graph: - an increase of the size of the different pulses, which is a measure of the decrease of the sharpness of the one or more knives in the cutting device; and

[0064] - a total load of the cutting device by a number of pulses, which is a measure of the decrease of the sharpness of the one or more knives in the cutting device.

[0065] A peak pulse 23 is, for instance, indicative of the impact of foreign material such as, for example, a stone. With a partial stoppage or damaged knives as a consequence.

[0066] An increase of liquid force is, for instance, indicative of more resistance in the cutting device which may be caused by a partial stoppage or damaged knives.

[0067] A relatively long pulse duration pd (not specifically represented) can also be indicative of a disturbance, for instance, of a partial product nearly jamming in the cutting device. This can have different causes. Possibly, the knives are dull or damaged. Also, the partial product may be too large or the cutting speed too low. Preferably, the data processor 10 is arranged to determine a pulse duration pd (i.e., pulse width measured in time) of each pulse 22 of the measuring signal S, and to compare it with a pulse duration threshold value, and to automatically carry out one or both of the steps la) and lb) if the pulse duration pd has reached said pulse duration threshold value. Pulse duration is represented in Figure 3 with arrows pdl and pd2, where pdl concerns a first (relatively short) pulse duration and pd2 a second pulse duration which is longer than the first pulse duration pdl.

[0068] To the skilled person it will be clear that the data processor 10 may, in particular, be arranged to determine a pulse duration pd by detecting both a starting time tO and an end time of a pulse 22, and to determine the pulse duration via pd=tl-tO (see Fig. 3). With the time dT between the pulses 22 in the signal S (a pulse intervening time dT, see Figure 3) an amount of supplied product can be optimized, which can be carried out by the data processor 10 (e.g., by determining that intervening time dT and adjusting a pump speed and / or by adjusting an above-mentioned system product supply flow depending on a determination of the pulse intervening time dT). If the time dT between the pulses is minimal, too much product is being supplied at the cutting speed set, in which case, for instance, the data processor 10 can automatically adjust (raise) the pump speed of the pump 3. According to an alternative implementation, the data processor 10 may be arranged to automatically adjust (lower) a system product supply flow (see arrow B in Fig. 2) when it appears that too much product P is being supplied to the knife block at the cutting speed set. In particular, the pump speed (i.e., cutting speed) is within certain limits optimal for the quality of the cut product.

[0069] Preferably, the system (i.e., the data processor 10) is implemented such that it can detect that too much product P is being supplied, to then automatically adjust the pump speed (i.e., cutting speed) or reduce the product supply to the system.

[0070] According to a further elaboration, as follows from the above, the detector 9 is arranged to record a signal course F(t) in time t, while the data processor 10 is arranged for processing the recorded signal course in time.

[0071] It has been found that good results can be obtained when the data processor 10 is implemented to process the measuring signal S issued by the detector 7, 8, 9, such that individual product cutting passes, in particular respective signal pulses 22, 22a, are detected in the measuring signal S by the data processor 10, the data processor 10 being arranged to determine one or more of the following pulse parameters of each pulse 22:

[0072] -a pulse shape; and

[0073] -a pulse energy. In this case, the data processor 10 may be arranged to compare a determined pulse parameter with a threshold value for that pulse parameter, and, preferably, to carry out a step la) and / or step lb) when the determined pulse parameter has reached the threshold value for that pulse parameter.

[0074] Determination of pulse energy may, for instance, be achieved by integration of a course of force, which will be clear to the skilled person.

[0075] Thus, a preferred embodiment comprises a system wherein the detector 9 is arranged to record a signal course F(t) (e.g., course of force) in time t, wherein the data processor 10 is arranged for processing the recorded signal course in time, wherein the data processor 10 is arranged to detect signal pulses 22, 22a in the recorded signal course F(t), and to integrate each detected pulse 22 over time t to determine a respective pulse surface. In that case, the data processor 10 is preferably arranged to compare a determined pulse surface with a pulse surface threshold value, and, preferably, to carry out step la) and / or step lb) when a determined pulse surface has reached the pulse surface threshold value.

[0076] Further, it appears that surprisingly good results can be obtained if a signal slope course of a measuring signal S is determined (from the signal course) by the data processor 10, for the purpose of monitoring the system.

[0077] Thus, the detector 9 may be arranged to record a signal course F(t) in time t, wherein the data processor 10 is arranged for processing the recorded signal course in time, wherein the data processor 10 is arranged to determine the derivative of the signal course (i.e., F’(t), dF(t) / dt) (see also Figures 7, 9-11), i.e., to determine a respective signal slope course F’(t), wherein the data processor 10 is arranged, in particular, to compare a determined signal slope with a signal slope threshold value and, preferably, to carry out step la) and / or step lb) when a determined signal slope has reached the signal slope threshold value. During use, the system can carry out a method for cutting products. With great advantage, the method comprises:

[0078] -supplying the products P under fluid pressure to at least one knife 4a of a cutting device 4, such that the products P under influence of the fluid pressure are cut by the at least one knife of cutting device 4;

[0079] -discharging and / or collecting the cut products P;

[0080] -monitoring the cutting process carried out by the at least one knife 4a, with issuance of a respective measuring signal S which is processed by a data processor 10; and:

[0081] -la) depending on the measuring signal S, automatically adjusting at least one parameter of the cutting process; and / or

[0082] -lb) automatically generating a disturbance signal if it follows from the measuring signal S that the cutting process is subject to a determined disturbance.

[0083] As mentioned, the liquid supply means are preferably configured to supply the products P one by one to the cutting device 4. To this end, for instance, a narrowing, known per se, or the like (i.e. , a product aligning system 6) may be provided in a supply channel of respective liquid supply means, which will be clear to the skilled person.

[0084] As follows from the above, at least a part 22, 22a of the respective measuring signal S may be associated with a sharpness of the at least one knife 4a (see, for example, Fig. 3), wherein the at least one knife 4a is automatically replaced with at least a second, sharper, knife 4b if it follows from the measuring signal S that the knife sharpness of the at least one knife 4a has a predetermined threshold value or a value below it. The threshold value of the sharpness of the knife is then, in particular, related to an above-mentioned threshold value DI of a signal pulse 22a of the measuring signal S. The measuring signal S issued by the detector 7, 8, 9 is preferably processed such that individual product cutting passes, in particular respective signal pulses 22, 22a, are detected in the measuring signal S by the data processor 10, and, for instance, are compared by the data processor 10 with the cutting pass threshold value DI.

[0085] In addition, or alternatively, the measuring signal S issued by the detector 7, 8, 9 can be processed by the data processor 10 such that passive periods 21 of the cutting device, which are between individual product cutting passes, are detected in the measuring signal S (see Figure 4), and, for instance, are compared with a passive period threshold value D2.

[0086] According to a further implementation, the at least one knife 4a, during use, is automatically taken away, depending on the measuring signal S issued by the detector 7, 8, 9, wherein, preferably, automatically at least a second knife 4b is supplied to the liquid supply means to replace an above- mentioned removed knife 4a. The automatic exchange of the at least one knife is preferably carried out as part of an above-mentioned step la) and / or step lb). Replacement, or exchange, of the at least one knife Ila may, for instance, be automatically carried out by the knife takeaway device 11 (in particular, under control of the data processor 10).

[0087] According to a further elaboration, the data processor 10 controls the liquid supply means to temporarily interrupt supply of products P to the cutting device 4 (e.g., by switching off the pump 3) when it follows from the processing of the measuring signal S issued by the detector 7, 8, 9 that: -at least one parameter of the cutting process is to be adjusted; and / or

[0088] -the cutting process is subject to a determined disturbance.

[0089] As follows from the above, use of the system comprises, for example, a method, wherein the data processor 10 determines a pulse duration pd of each pulse 22 of the measuring signal S, and compares the determined pulse duration pd with a pulse duration threshold value. One or more of the steps la) and lb) may, for instance, be carried out if a determined pulse duration pd has reached the pulse duration threshold value. During use, preferably a signal course F(t) in time t is recorded (see Figures 3, 4), wherein the data processor 10 processes the recorded signal course in time, and, in particular, automatically carries out step la) and / or step lb) depending on the result of the processing of the signal course F(t).

[0090] According to an especially advantageous elaboration, the data processor 10 processes the measuring signal S such that individual product cutting passes, in particular respective signal pulses 22, 22a, are detected in the measuring signal S by the data processor 10, wherein the data processor 10 determines one or more of the following pulse parameters of each pulse 22:

[0091] -a pulse shape; and

[0092] -a pulse energy.

[0093] The data processor 10 can compare a determined pulse parameter with a threshold value for that pulse parameter, and, preferably, carry out step la) and / or step lb) when the determined pulse parameter has reached the threshold value for that pulse parameter.

[0094] Additionally or alternatively, during use, a signal course F(t) in time t (of the measuring signal S) can be recorded, wherein the data processor 10 processes the recorded signal course in time, wherein the data processor 10 detects signal pulses 22, 22a in the recorded signal course F(t), and integrates each detected pulse 22 over time (t) to determine a respective pulse surface. The data processor 10 can then, in particular, compare a determined pulse surface with a pulse surface threshold value, and, preferably, carry out step la) and / or step lb) when a determined pulse surface has reached the pulse surface threshold value.

[0095] Additionally or alternatively, a signal course F(t) in time t (of the signal S) can be recorded, wherein the data processor 10 processes the recorded signal course in time, wherein the data processor 10 determines a respective signal slope course F’(t). In that case, the data processor 10 can, in particular, compare a determined signal slope with a signal slope threshold value, and, preferably, carry out step la) and / or step lb) when a determined signal slope has reached the signal slope threshold value.

[0096] It has been found that in this manner system disturbances can be reliably detected.

[0097] Figure 5 shows a further elaboration of the system shown in Figure 2, which is different in that it is provided with at least a second cutting device 4’. Each cutting device 4, 4’ is provided with a respective detector 9, 9’ configured to monitor a cutting process carried out by the knife of the respective cutting device and to issue a respective measuring signal. The liquid supply means 3, 50 are preferably arranged to supply supplied products P selectively to the several cutting devices 4, 4’, in particular, to switch between supply to those cutting devices 4, 4’. The liquid supply means comprise, in particular, at least a channel split to a first channel part 50L for supply of products P to the first cutting device 4 and to a second channel part 50R for supply of products to the second cutting device 4’ (it will be clear that such channel parts can be available when utilizing more than two cutting devices 4, 4’). Downstream of the cutting devices 4, 4’, respective product discharge channels preferably come together in a common discharge channel 50U (to discharge cut product for the purpose of further processing).

[0098] A product stream regulator 12 controllable by the data processor 10, for example a valve gear, may be provided to determine to which of the several cutting devices 4, 4’ the liquid product stream is supplied. In this manner, the data processor 10 can, for instance, stop the liquid product stream to one cutting device and start supply to the other cutting device if it appears that the first-mentioned cutting device is subject to a determined disturbance (which can be determined on the basis of a respective detector measuring signal S, as has been described hereinabove). Thereupon, the disturbance can be remedied (for instance, by automatically exchanging a knife or knife block of the cutting device where the disturbance occurs), without the cutting process needing to be discontinued to that end.

[0099] Figure 6 schematically shows an example of a part of a further elaboration of the invention, comprising a sorting system 30 to sort products. The sorting system 30 may be arranged, for instance, to sort supplied products P on the basis of a determined product parameter (e.g., product size or product weight) before the products are supplied to a series of cutting systems 31, 32, 33. Such a sorting system is known per se.

[0100] According to a non-limiting example, the sorting system 30 may, for instance, be provided with a reception reservoir 34 which is provided with a sorting construction 35 which is arranged to pass products to different product discharge channels 36a, 36b, 36c depending on the respective product parameter. The sorting construction 35 can be, for example, a screen or mesh-containing element, provided with first product passages of a first size to pass only relatively small products P, and to supply these to a downstream first discharge channel 36a. The sorting construction 35 may be provided with second product passages of a second size to pass only medium-sized products P, and to supply these to a downstream second discharge channel 36b. The sorting construction 35 may be provided with third product passages of a third size to pass large products P, and to supply these to a downstream third discharge channel 36c. In this case, the first product passages are (hence) smaller than the second product passages, and the second product passages are smaller than the third product passages.

[0101] Products having a first value (e.g., in a first range) of the product parameter may, during use, for instance be intended to be cut by a first product cutting system 31, and products having a second value (e.g., in a second range) of the product parameter similarly so by a second product cutting system 32. In particular, the first product parameter value (e.g., the first range) differs from the second product parameter value (e.g., the second range). It will be clear that such a sorting system may be arranged to subdivide products into more than two different values (ranges), for example, three (in which case a respective third product cutting system 33 may be available to cut products having a third value, or in a third range).

[0102] One or more, and preferably each, of the series of cutting systems 31, 32, 33 are preferably implemented as a cutting system according to the present invention. The several cutting systems 31, 32, 33 may, for instance, be provided with a common data processor 10 to process the detector signals S (from the detectors 7, 8, 9 of each of the cutting systems 31, 32, 33), and to carry out suitable action or cutting system control (as described in the above). According to a further elaboration, the sorting system 30 is integrated with the series of cutting systems 31, 32, 33.

[0103] In the example shown in Figure 6, the sorting system includes sorting regulation means 35, for example, valve means, which are implemented to readjust a product sorting. In particular, the regulation means 35 are controllable for readjustment of supply of products to downstream cutting systems 31, 32, 33, for instance to adjust or to change a sorting made by an above-mentioned sorting construction 35. Preferably, these sorting regulation means are controllable by the data processor 10, which provides particular advantages. Thus, the data processor 10 may be arranged to adapt a sorting of products P to be supplied to one or more of the several cutting systems 31, 32, 33, depending on an above-mentioned detector signal S. In other words: with the help of an above-mentioned detector signal S, settings of the sorter 30 can be optimized.

[0104] As follows from the above, the invention can provide a data processor 10 that may be arranged to record, and analyze, the force that a partial product and the transport liquid exert on the cutting device in time.

[0105] According to a further elaboration, a measuring result of a flow meter 7 (i.e., a liquid flow measured by that meter 7) can be sent to the data processor, for instance, to provide additional information. With a measured liquid flow, for instance a time difference can be converted to a distance.

[0106] According to a further elaboration, the data processor 10 may be arranged, for instance, to use one or more of the following (measuring) data / signals S:

[0107] - course of force in time;

[0108] - flow of the transport medium (i.e., the transport liquid);

[0109] - pressure after the pump; and / or

[0110] - size of the product P to be cut, for example, a product measured by a camera.

[0111] Further, the data processor 10 may be arranged to automatically adjust one or more of the following parameters, depending on the determination of above-mentioned (measuring) data / signals S:

[0112] - a parameter for replacing the cutting device;

[0113] - a parameter for adjusting a cutting speed;

[0114] - a parameter for adjusting a size of the product supply; and / or

[0115] - a parameter for adjusting the product size of the partial product. Adjusting the product size means, for example for potatoes, that a sorting size is adjusted. In that case, a sorter is disposed upstream of the cutting device in the production line (see Figure 6). Further, a further elaboration provides application of a measuring device, for example, a camera, to measure the size of the products after sorting (by the sorter). A measured product size can also be used as an input parameter for the data processor 10.

[0116] Results

[0117] Figures 7-11 show results of an exemplary embodiment of the invention.

[0118] Figure 7 shows a detector-delivered detector signal Si (in this case a measured course of force as a function of time, concerning an above- mentioned force detector 9) and also shows, determined from that signal S 1 by the data processor 10, an associated signal slope course Si’ (i.e., the derivative of the measured force as a function of time). In this case, the signal Si contains a pulse Y1 concerning a correct product cutting, where a single product P passes the knife block and is cut by the knife block into product parts Q.

[0119] Figure 8 shows a detector signal course S2 (from the force detector 9) of a double product cutting. The detector signal S2 shown (delivered by an above-mentioned detector) concerns simultaneous cutting of two products P by the knife block, which results in an elongated pulse shape Y2. This elongated pulse shape can preferably be detected by the data processor 10, to then automatically cause, for instance, a product flow to the system (i.e., supply of a number of products P per unit time) to be lowered (so as to increase the mutual distance of products P in the water stream W). To this end, the data processor 10 may be coupled to a product supply system (not shown), in order that the data processor 10 can regulate a product supply flow supplied by that product supply system (see arrow B in Fig. 2). Also, for instance, (given an equal product supply flow to the system) a pump speed of the pump 3 may be automatically increased (to enlarge the mutual distance of products P in the water stream W), which will be clear to the skilled person. The data processor 10 may be arranged, for instance, to calculate the surface area of the measured pulse, by means of integration, for the purpose of detection of such a double cutting (in particular, by comparing a determined pulse surface of the pulse Y2 with a predetermined pulse surface threshold value).

[0120] Figure 9 differs from the result shown in Fig. 7 in that the detector signal course S3 and associated (by data processor 10 determined) signal slope course S3’ concern a knife block stoppage. The force (F(t) on the cutting knife increases very rapidly. This is shown by the steep ascending flank and the high peak value Y3’ of the derivative S3’, which is preferably automatically detected by the data processor 10 (which can then, on the basis of this detection, automatically carry out a step la) and / or lb)).

[0121] Figure 10 differs from the result shown in Fig. 7 in that the detector signal course S4 and associated signal slope course S4’ concern product cutting by a soiled knife block. In particular, the graph S4 shows a pulse Y4 where a product P is being cut while there are still plant remains present in the knife block. The quality of the cut product Q is not acceptable then. The derivative of the measured detector signal S4, i.e., the associated signal slope course S4’, has an erratic (non-fluent) shape, for instance including a series of brief fluctuations, each of less than ten milliseconds, which is preferably automatically detected by the data processor 10, to then carry out a step la) and / or lb). According to a further elaboration, this erratic shape (e.g., above-mentioned fluctuations) can be detected - by the data processor - by determining a second derivative, i.e., F”(t) (dF2 / dt2) and / or by determining a respective signal-to-noise ratio, which will be clear to the skilled person.

[0122] Figure 11 differs from the result shown in Fig. 7 in that the detector signal course S5 and associated signal slope course S5’ concern cutting by a blunt knife block. In this case, the cutting pulse Y5 has a relatively long pulse duration pdY, which is preferably detected by the data processor 10 and is compared with an above-mentioned (predetermined) pulse duration threshold value (to then automatically carry out a step la) and / or lb)). Further, the graph of the derivative of the detector signal appears to be a non-fluent graph S5’, with a number of sharp peaks Y5’; the data processor 10 is therefore preferably implemented to detect this deviation in the derivative graph Y5’ (with respect to a normal fluent graph Yl’, see Fig. 7) by means of suitable signal processing (for example, a 2ndderivative determination, Fourier transform, or the like), and then to automatically carry out an above-mentioned step la) and / or lb) when such a deviation is established. The present invention provides various advantages. Thus, material costs can be reduced when the at least one knife is exchanged only when this is necessary. The same holds for costs of labor. Unplanned replacements of the at least one knife (for instance, due to stoppages) can be prevented. The production capacity of the cutting system can thus be optimally used. A good or improved quality of the cut product can be achieved, so that less cut product needs to be rejected. Since a good or even improved quality of the cut product can be achieved, in a follow-up process less liquid can be absorbed by the product (such as, for example, frying oil, if a frying process is to be carried out on the cut product).

[0123] It will be clear to the skilled person that the invention is not limited to the exemplary embodiments described. Various changes are possible within the framework of the invention as defined in the claims.

[0124] Thus, the detector, configured to monitor a cutting process carried out by the knife, and to issue a respective measuring signal, may be implemented in different manners. According to a further elaboration, the detector may be arranged to detect an acoustic signal, which signal relates to the cutting process, wherein the data processor can analyze the acoustic signal, for instance, to detect or analyze one or more knife breaks of the at least one knife (for this, see WO9933038A1 Acoustic Emission Severance Detector And Method).

[0125] Further, an automatic replacement of the at least one knife can be achieved in different manners. In practice, there are already different systems available for knife block replacement, for example, a knife block exchange system supplied by applicant. The system can be provided with a holder in which two knife blocks are placeable, which are displaceable (by a pneumatic cylinder) between an active cutting position and a passive position. The knife block movement is, for example, vertical. Further, systems are known where several parts are implemented in duplicate. These double parts are then fixedly set up, and with a three-way valve a choice can be made as to which path is followed. Thus, for instance, the pump, the aligning system and the knife block are doubled. In another implementation, such an aligning system and the cutting device are doubly implemented. Further, the system may be arranged to temporarily discontinue the product supply during an above-mentioned exchange of the one knife 4a, but this is not requisite and depends, for instance, on the speed of the knife exchange. Thus, the knife takeaway device 11 may be implemented to exchange the at least one knife 4a sufficiently fast (e.g., within one second or a few seconds) during the product supply (i.e., pump activation).

Claims

CLAIMS1. A system for cutting products, for example, potatoes, comprising: -a cutting device (4), provided with at least one knife (4a); and- liquid supply means, arranged to supply the products (P) in a liquid stream to the at least one knife (4a) of the cutting device (4), such that the products (P) under influence of fluid pressure are cut by the at least one knife of cutting device (4); wherein the system is provided with at least one detector (7, 8, 9), configured to monitor a cutting process carried out by the knife (4a) and to issue a respective measuring signal (S), wherein the system comprises a data processor (10) which is arranged to process the measuring signal (S) issued by the detector (7, 8, 9), and to:-la) automatically adjust at least one parameter of the cutting process, depending on said measuring signal (S); and / or-lb) issue a disturbance signal if it follows from the measuring signal (S) that the cutting process is subject to a determined disturbance.

2. A system according to claim 1, wherein the detector (7, 8, 9) is implemented such that at least a part (22, 22a) of the respective measuring signal (S) is proportional to a sharpness of the at least one knife (4a), wherein the detector (7, 8, 9) is, for instance, configured to generate a measuring signal (S) associated with a cutting force produced by the knife (4a) and / or a measuring signal associated with a fluid pressure exerted on the products (P).

3. A system according to claim 1 or 2, wherein the data processor (10) is implemented to process the measuring signal (S) issued by the detector (7, 8, 9) such that individual product cutting passes, in particular respective signal pulses (22, 22a), are detected in the measuring signal (S)by the data processor (10), and, for instance, can be compared by the data processor (10) with a cutting pass threshold value (DI).

4. A system according to any one of the preceding claims, wherein the data processor (10) is implemented to process the measuring signal (S) issued by the detector (7, 8, 9) such that passive periods of the cutting device which are between individual product cutting passes, are detected in the measuring signal (S) by the data processor (10), and can be compared by the data processor (10) with a passive period threshold value (D2).

5. A system according to any one of the preceding claims, wherein the liquid supply means are configured to supply the products (P) one by one to the cutting device (4).

6. A system according to any one of the preceding claims, provided with a knife takeaway device (11), arranged for automatically removing the at least one knife (4a) from the liquid supply means, wherein the data processor (10) is implemented to cooperate at least with the knife takeaway device (11), to automatically remove the at least one knife (4a) depending on the measuring signal (S) issued by the detector (7, 8, 9), wherein the knife takeaway device (11) is preferably arranged to automatically supply at least a second knife (4b) to the liquid supply means for replacement of a knife (4a) removed by the takeaway device.

7. A system according to any one of the preceding claims, wherein the data processor (10) is arranged to cooperate with the liquid supply means, for the purpose of temporarily interrupting supply of products (P) to the cutting device (4), depending on a result of the processing of the measuring signal (S) issued by the detector (7, 8, 9).

8. A system according to any one of the preceding claims, wherein the at least one knife (4a) is part of a knife cutting block, comprising at least one series of knife parts equidistantly spaced apart, which, for instance, define rectangular knife passages.

9. A system according to any one of the preceding claims, wherein the data processor (10) is implemented to process the measuring signal (S) issued by the detector (7, 8, 9) such that individual product cutting passes, in particular respective signal pulses (22, 22a), are detected in the measuring signal (S) by the data processor (10), wherein the data processor (10) is arranged to determine a pulse duration (pd) of each pulse (22) of the measuring signal (S) and compare it with a pulse duration threshold value, and to automatically carry out one or both of said steps la) and lb) if the pulse duration (pd) has reached said pulse duration threshold value.

10. A system according to any one of the preceding claims, wherein said detector (9) is arranged to record a signal course (F(t)) in time (t) of the measuring signal (S), wherein the data processor (10) is arranged for processing the recorded signal course in time.

11. A system according to any one of the preceding claims, wherein the data processor (10) is implemented to process the measuring signal (S) issued by the detector (7, 8, 9) such that individual product cutting passes, in particular respective signal pulses (22, 22a), are detected in the measuring signal (S) by the data processor (10), wherein the data processor (10) is arranged to determine one of more of the following pulse parameters of each pulse (22):-a pulse shape; and-a pulse energy; wherein the data processor (10) is arranged to compare a determined pulse parameter with a threshold value for that pulse parameter, and, preferably, to carry out step la) and / or step lb) when the determined pulse parameter has reached the threshold value for that pulse parameter.

12. A system according to any one of the preceding claims, wherein said detector (9) is arranged to record a signal course (F(t)) in time (t) of the measuring signal (S), wherein the data processor (10) is arranged for processing the recorded signal course in time, wherein the data processor(10) is arranged to detect signal pulses (22, 22a) in the recorded signal course (F(t)), and to integrate each detected pulse (22) over time (t) to determine a respective pulse surface, wherein the data processor (10) is, in particular, arranged to compare a determined pulse surface with a pulse surface threshold value, and, preferably, to carry out step la) and / or step lb) when a determined pulse surface has reached the pulse surface threshold value.

13. A system according to any one of the preceding claims, wherein said detector (9) is arranged to record a measuring signal course (F(t)) in time (t), wherein the data processor (10) is arranged for processing the recorded signal course in time, wherein the data processor (10) is arranged to determine a respective signal slope course (F’(t)), wherein the data processor (10) is, in particular, arranged to compare a determined signal slope with a signal slope threshold value, and, preferably, to carry out step la) and / or step lb) when a determined signal slope has reached the signal slope threshold value.

14. A system according to any one of the preceding claims, wherein the data processor (10) is arranged to detect a time dT between successive pulses (22) in the measuring signal (S), in particular, to optimize an amount of supplied product (P).

15. A sorting system, provided with a reception reservoir (34) which is provided with a sorting construction (35) which is arranged to pass products to different product discharge channels (36a, 36b, 36c) depending on a respective product parameter, wherein the sorting system (30) is integrated with a series of cutting systems (31, 32, 33) to cut the products, wherein one or more, and preferably each, of the series of cutting systems (31, 32, 33) is implemented as a cutting system according to any one of the preceding claims.

16. A sorting system according to claim 15, wherein the several cutting systems (31, 32, 33) are provided with a common data processor (10) toprocess the measuring signals (S) from the respective detectors (7, 8, 9), for instance to carry out a suitable action or cutting system control.

17. A sorting system according to claim 16, wherein the data processor (10) is arranged to adjust a sorting of products (P) to be supplied to one or more of the several cutting systems (31, 32, 33), depending on a measuring signal (S).

18. A method for cutting products, for example potatoes, for instance utilizing a system according to any one of the preceding claims, the method comprising:-supplying the products (P) under fluid pressure to at least one knife (4a) of a cutting device (4), such that the products (P) under influence of the fluid pressure are cut by the at least one knife of cutting device (4);-discharging and / or collecting the cut products (P);-monitoring the cutting process carried out by the at least one knife (4a), with issuance of a respective measuring signal (S) which is processed by a data processor (10); and:-la) depending on said measuring signal (S), automatically adjusting at least one parameter of the cutting process; and / or -lb) generating a disturbance signal if it follows from the measuring signal (S) that the cutting process is subject to a determined disturbance.

19. A method according to claim 18, wherein at least a part (22, 22a) of the respective measuring signal (S) is associated with a sharpness of the at least one knife (4a), wherein the at least one knife (4a) is automatically replaced with at least a second, sharper, knife (4b) if it follows from the measuring signal (S) that the knife sharpness of the at least one knife (4a) has a predetermined threshold value or is below it.

20. A method according to claims 18 or 19, wherein the issued measuring signal (S) is processed such that individual product cutting passes, in particular respective signal pulses (22, 22a), are detected in the measuringsignal (S) by the data processor (10), and, for instance, can be compared by the data processor (10) with a cutting pass threshold value (DI).

21. A method according to any one of claims 18-20, wherein the measuring signal (S) is processed by the data processor (10) such that passive periods of the cutting device which are between individual product cutting passes are detected in the measuring signal (S), and, for instance, are compared with a passive period threshold value (D2).

22. A method according to any one of the preceding claims 18-21, wherein the products (P) are one by one supplied to the cutting device (4), in particular utilizing a narrowing (6) in a supply channel of respective liquid supply means.

23. A method according to any one of the preceding claims 18-22, wherein the at least one knife (4a) is automatically taken away depending on measuring signal (S), wherein preferably automatically at least a second knife (4b) is furnished to the liquid supply means for replacing a removed knife (4a).

24. A method according to any one of the preceding claims 18-23, wherein the data processor (10) controls the liquid supply means to temporarily interrupt supply of products (P) to the cutting device (4) when it follows from the processing of the measuring signal (S) that:-at least one parameter of the cutting process is to be adjusted; and / or -the cutting process is subject to a determined disturbance.

25. A method according to any one of the preceding claims, comprising:- determining by the data processor (10) of a pulse duration (pd) of each pulse (22) of the measuring signal (S); and- comparing of the determined pulse duration (pd) with a pulse duration threshold value; wherein one or more of the steps la) and lb) are carried out if the pulse duration (pd) has reached said pulse duration threshold value.

26. A method according to any one of the preceding claims, comprising recording of a signal course (F(t)) of the measuring signal (S) in time (t), wherein the data processor (10) processes the recorded signal course in time, and, in particular, automatically carries out step la) and / or step lb) depending on the result of the processing of the signal course (F(t)).

27. A method according to any one of the preceding claims, wherein the data processor (10) processes the measuring signal (S) such that individual product cutting passes, in particular respective signal pulses (22, 22a), are detected in the measuring signal (S) by the data processor (10), wherein the data processor (10) determines one or more of the following pulse parameters of each pulse (22):-a pulse shape; and-a pulse energy; wherein the data processor (10) compares a determined pulse parameter with a threshold value for that pulse parameter, and preferably carries out step la) and / or step lb) when the determined pulse parameter has reached the threshold value for that pulse parameter.

28. A method according to any one of the preceding claims, wherein a signal course (F(t)) in time (t) of the measuring signal (S) is recorded, wherein the data processor (10) processes the recorded signal course in time, wherein the data processor (10) detects signal pulses (22, 22a) in the recorded signal course (F(t)), and integrates each detected pulse (22) over time (t) to determine a respective pulse surface, wherein the data processor (10), in particular, compares a determined pulse surface with a pulse surface threshold value, and, preferably, carries out step la) and / or step lb) when a determined pulse surface has reached the pulse surface threshold value.

29. A method according to any one of the preceding claims, wherein a measuring signal course (F(t)) in time (t) is recorded, wherein the data processor (10) processes the recorded signal course in time, wherein the dataprocessor (10) determines a respective signal slope course (F’(t)), wherein the data processor (10), in particular, compares a determined signal slope with a signal slope threshold value and, preferably, carries out step la) and / or step lb) when a determined signal slope has reached the signal slope threshold value.

30. A method according to any one of the preceding claims, wherein the data processor (10) detects a time dT between successive pulses (22) in the measuring signal (S), and, in particular, optimizes an amount of supplied product (P) on the basis of a detected pulse intervening time dT.

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