Sensing head for determining the length of the abdominal cavity of a slaughtered, decapitated and gutted fish, processing station having a knife unit and a sensing head of this type, and device and method for processing, in particular filleting, slaughtered, decapitated and gutted fish

A measuring head for determining the length of the abdominal cavity of a slaughtered, beheaded and gutted fish being transported head-end first in the transport direction includes at least one measurement sensor and at least one position sensor, which can be triggered by the measurement sensor and is connected to a control device. The control device is for picking up and processing the incoming measurement signals. The measuring head is configured and adapted at least partly for being positioned between two circular knives of a knife assembly for performing a filleting cut on the fish, in such a way that the or each measurement sensor can be operatively connected to a flank bone of the fish that is closest to the anus of the fish. A working station includes at least one knife assembly and the measuring head. An apparatus and a method for processing fish are also disclosed.

FIELD OF THE INVENTION

The invention relates to a measuring head configured and adapted for determining the length of the abdominal cavity of a slaughtered, beheaded and gutted fish being transported head-end first in the transport direction T, comprising at least one measurement sensor and at least one sensor, which can be triggered by the measurement sensor and is connected to a control device, which is configured and adapted for picking up and processing the incoming measurement signals.

BACKGROUND OF THE INVENTION

The invention further relates to a working station configured and adapted for processing slaughtered, beheaded and gutted fish, comprising a knife assembly having two cutting heads, each of which comprises a circular knife that can be rotationally driven and a drive unit for rotationally driving the circular knife, the two circular knives being oriented in a manner tilted in a V shape with respect to one another and being oriented in a manner tilted towards one another in the opposite direction to the transport direction T of the fish being processed, and comprising a measuring head for determining the length of the abdominal cavity of the slaughtered, beheaded and gutted fish.

The invention further concerns an apparatus for processing, in particular filleting, slaughtered, beheaded and gutted fish, comprising a transport device for holding and transporting the fish head-end first in the transport direction T along a transport path, and at least one working station along the transport path for processing the fish.

Furthermore, the invention concerns a method for processing, in particular filleting, slaughtered, beheaded and gutted fish, comprising the steps of: feeding a fish head-end first to at least two working stations for working the fish by means of a transport device in the transport direction T, performing a plurality of processing cuts on the fish being processed, by means of knife assemblies as working stations, by successively transporting the fish being processed along two rotationally driven circular knives of a knife assembly, a belly cut being performed first using a first knife assembly, and at least one flank cut being performed thereafter using a second knife assembly arranged downstream of the first knife assembly in the transport direction T, and at least the knife assembly for performing the flank cuts being controlled on the basis of measurement data, established by means of a measuring head, regarding the size of the fish.

Measuring heads, working stations and apparatuses of this kind are used in the animal processing industry, and in particular for filleting fish, in order to fillet the fish in the most precise and high-yielding manner possible. When filleting slaughtered, beheaded and gutted fish, a multitude of different cuts have to be performed to fully separate the flesh, and in particular the fillets, from the fish skeleton to a high quality, i.e. in particular also without any bones or bone fragments. For this purpose, the fish are transported head-end first along a transport path in a transport direction T by means of a transport apparatus. At least two working stations are arranged along this transport path. Preferably, more than two working stations are arranged one behind the other in the transport direction T in order to perform different working steps, namely different filleting cuts. Besides the belly cuts and the flank cuts, said filleting cuts preferably also include, for example, flank bone cuts, backbone cuts, pin bone or belly flap cuts, separating cuts and other cuts.

SUMMARY OF THE INVENTION

The individual working stations each comprise a knife assembly, each having a pair of separating knives. Each separating knife of a pair of separating knives is configured as a circular knife for performing belly cuts and flank cuts, for example. The circular knives can be configured and arranged as fixed circular knives along the transport path, for example in the case of a belly cut. In this case, the two circular knives cut the lower radial bones free from the end of the abdominal cavity, i.e. directly behind the flank bones, as far as the tail root of the fish. The circular knives and/or the knife assemblies comprising the circular knives can, however, also be configured to be movable and adjustable, i.e. controllable in terms of their position and/or orientation, in order to be moved along an optimised cutting line for each filleting cut, i.e. in particular the flank cuts and the pin bone or belly flap cuts. To be able to precisely control these circular knives and/or knife assemblies, i.e. to determine, for example in relation to the flank cuts, the start time for the circular knives to be engaged with the fish and the end time for the knives to be disengaged from the fish at the end of the abdominal cavity, it is essential to know the size of each fish located in the working station. The same also applies to other filleting cuts, and in particular also to the pin bone or belly flap cut, in order to be able to precisely track the pin bone line when moving the circular knives or the knife assemblies so that the detached belly flaps contain all the pin bones.

The size of the fish can be determined or established in different ways. In one option, the thickness of the head is measured using suitable measuring heads in order to determine therefrom the size of the fish or the length of the abdominal cavity and the course of the pin bone line. However, this measurement is imprecise, so it is unsuitable for controlling the knife assemblies. In other options, the length of the abdominal cavity is measured or established. Ultimately, the length of the abdominal cavity leads to conclusions on the size of the fish, the course of the skeleton, etc., and this knowledge is important for optimally controlling the circular knives or the knife assemblies carrying the circular knives. Current measuring heads and measuring means are, however, only suitable to a limited extent for accurately determining the length of the abdominal cavity and thus the size of the fish and the course of the skeleton. Accordingly, the control is imprecise, leading to losses in yield during filleting and reductions in the quality of the obtained fillets, for example owing to bone fragments in the fillets. Optical probes for measuring the length of the abdominal cavity inherently pose challenges since debris inside the abdominal cavity distorts the measurement result. Consequently, mechanical (abdominal cavity) probes, or so-called height sensors, are often used, but these do not allow the longitudinal position, longitudinal extension and size of the fish to be determined exactly enough, leading to inaccurate cutting results and related losses in yield.

Therefore, the object of the invention is to create a compact and dynamic measuring head that ensures the length of the abdominal cavity is measured reliably and precisely. The object is also to propose a corresponding working station, a corresponding apparatus and a corresponding method for filleting slaughtered, beheaded and gutted fish.

This object is achieved by a measuring head of the type mentioned at the outset in that the measuring head is configured and adapted at least partly for being positioned between two circular knives of a knife assembly for performing a filleting cut on the fish, in such a way that the or each measurement sensor can be operatively connected to a flank bone of the fish that is closest to the anus of the fish. The last flank bone before the anus of the fish gives an accurate position signal for determining the length of the abdominal cavity and controlling the circular knives, or the knife assemblies carrying the circular knives, on that basis. As a result of the fish being transported, the measurement sensors located within the abdominal cavity, which tapers towards the anus, are entrained by the last flank bone, which determines the end of the abdominal cavity, and thereby trigger the measurement signal, which can then be used for controlling the knife assemblies. Configuring the measuring head according to the invention to be positioned at least partly between two circular knives allows for a particularly compact design while also ensuring that the or each measurement sensor can be guided within the abdominal cavity closely along a backbone on which the flank bones are arranged.

Advantageously, the measuring head comprises a base body that can be fastened to a machine frame in a stationary manner, at least one measurement sensor being arranged on the base body in a rotatably mounted manner. The stationary fastening to a machine frame includes fastening, preferably releasable fastening, to a frame, a support or the like and ensures, in conjunction with the rotatable mounting of each measurement sensor on the base body, that a sufficiently high probing force can be implemented in order, for example, to reduce the influence of interfering bodies during the measurement. Since it is arranged on a base body, the measuring head according to the invention can also be used in particular as a retrofittable module on existing machines.

Expediently, the base body is formed in the manner of a jib and comprises a fastening arm and a supporting arm on which the or each measurement sensor is arranged in a rotatably mounted manner. The base body can have any shape and be configured, for example, as a bracket, a support or the like. The jib-like configuration makes it simpler, on the one hand, to assemble the measuring head, or at least parts thereof, between two circular knives of a knife assembly, and, on the other hand, to insert the or each measurement sensor into the abdominal cavity in an interference-free manner and to guide within the abdominal cavity such that the entrainment of the or each measurement sensor by the last flank bone trailing in the transport direction T is reliably ensured.

A particularly advantageous embodiment is characterised in that the measuring head comprises two measurement sensors that are arranged at a distance from one another on opposite sides of the supporting arm. Providing two measurement sensors active on both sides of a backbone increases the likelihood that at least one of the last two flank bones arranged on both sides of the backbone before the anus entrains one of the two measurement sensors and triggers the measurement signal. For this purpose, the measurement sensors can be configured to be rotatable about a joint axis of rotation. The two measurement sensors can also be assigned to a joint shaft that is rotatably mounted in the base body. In those cases, the deflection of a measurement sensor inevitably leads to the deflection/entraining of the second measurement sensor. The measurement sensors can also be arranged so as to be individually mounted on the supporting arm, preferably by/on a joint spindle that is mounted in the supporting arm.

In a particularly preferred development, the or each measurement sensor is produced from a thin, flexible spring steel sheet. This creates a mass-optimised measurement sensor that ensures high dynamic performance for quick measurement cycles (movement from a standby position into a measuring position and back). The material thickness thin describes material thicknesses of the spring steel sheets of preferably thinner than 1 mm and particularly preferably thinner than 0.5 mm. Preferably, each spring steel sheet forming the measurement sensor is not whole over its entire surface but has cut-outs in order to use less material and thus reduce the weight. As a result of the configuration according to the invention, the measurement sensors are elastically deformable so as to be able to adapt to in particular inner surfaces of the circular knives, which are turned towards one another, of a knife assembly. As well as the rotation of the measurement sensors as a first movement dimension about the axis of rotation or together with the shaft, the resilient configuration creates a second movement dimension for the measurement sensors or parts thereof. Overall, a lighter measurement sensor having less inertia is created, as a result of which a quick return can be achieved for short measurement cycles, as mentioned above. During a measurement cycle, a probe tip of each measurement sensor passes through the cutting region or cutting edges of the circular knives twice at the point at which the distance between the two circular knives of a knife assembly is the smallest.

Expediently, the two measurement sensors arranged at a distance from one another and rotatably mounted on the supporting arm are interconnected by means of a cross-brace at least at one point. This direct connection, formed in addition to the existing indirect connection by an axis of rotation or shaft, creates stability in order, for example, to be able to apply a greater probing force and improves the synchronised pivoting of the two low-mass and thus dynamically optimised measurement sensors.

Advantageously, a first cross-brace is formed upstream of the axis of rotation of the measurement sensors in the transport direction T of the fish being processed, the cross-brace being formed by a bolt that is releasably fastened to both measurement sensors and is oriented transversely to the transport direction T. The connection of the two measurement sensors can also be produced by screws, struts or any other suitable connecting or fastening means.

Advantageously, a second cross-brace is formed downstream of the axis of rotation of the measurement sensors in the transport direction T of the fish being processed, the cross-brace being formed by a bolt that is releasably fastened to both measurement sensors and is oriented transversely to the transport direction T. The connection of the two measurement sensors can also be produced by screws, struts or any other suitable connecting or fastening means. The two cross-braces not only provide stability for the measuring head, as is required in order for an adequately high probing force to be applied, but also ensure that the two measurement sensors are at a defined distance from one another and remain at said distance even during the pivoting movement from the standby position into the measuring position and back.

Advantageously, the second cross-brace interacts with a stop element arranged on the base body. By way of example, the stop element is an adjustable bolt by means of which the length of the pivot range of the measurement sensors can be limited up to the measuring position such as to ensure that the length of the pivot range is adapted to each specific case.

In a preferred embodiment, each measurement sensor comprises a main body having a probe tip. When the measurement sensors are in the standby position, the probe tip points in the opposite direction to the transport direction T such that the last flank bone located before the anus reliably and inevitably hits the probe tip and thus pivots the measurement sensor out of the standby position into the measuring position.

Advantageously, in addition to the probe tip, the main body has a sensing lug that can be operatively connected to the sensor. The main body, sensing lug and probe tip of each measurement sensor are preferably formed in one piece. However, there is also the option of each measurement sensor being assembled from a plurality of individual parts. By way of example, the sensor can be a simple photoelectric sensor as an initiator. The sensor can also be configured as a distance sensor. Other configurations of the sensor are also possible. There is also the option of providing a plurality of sensors or other detection means.

Advantageously, the sensor is arranged on the base body. Particularly preferably, the sensor is arranged directly or indirectly on the fastening arm of the base body. The or each sensor, which is preferably releasably fastened to the fastening arm, can be arranged directly on the fastening arm. Adjustable fastening directly to the fastening arm is also possible, for example an adjustability within a slot or the like. The or each sensor can also be fastened to the fastening arm indirectly, for example by means of an adjustment plate, the adjustment plate preferably being adjustably arranged on the fastening arm. However, the or each sensor can also be arranged at a different position on the base body or be provided separately from the base body.

A particularly preferred development is characterised in that the or each measurement sensor is held in a standby position in a spring-biased manner, a spring element being tensioned between the or each measurement sensor and the base body. The spring element, or optionally also two or more spring elements, assists with the application of an adequately high probing force.

Advantageously, the or each measurement sensor is configured and adapted so as to be deflectable into a measuring position counter to the spring force of the spring element. In the measuring position, the or each measurement sensor triggers the measurement signal. The measuring position is limited and determined by means of the preferably adjustable stop element. The or each spring element ensures that the measurement sensors are quickly returned to the standby position once the fish has deflected the measurement sensors into the measuring position and then released them again by being transported further. Short measuring cycles can thus be achieved such that fish transported one after the other to the measuring head can be reliably measured. The spring force by which the measurement sensors are held in the standby position makes the measurement sensors even more sensitive such that more precise measurement results can be obtained.

Expediently, the sensing lug at least partly covers the sensor in the measuring position. The or each sensor can be triggered, in particular optically and/or electronically, in the measuring position, which is located outside the abdominal cavity of the fish being measured.

Advantageously, the spring element is tensioned between the first cross-brace and the supporting arm of the base body. Thus, in addition to a compact design, a synchronised pivoting movement out of the measuring position back into the standby position is ensured for both measurement sensors. The or each spring element can also be arranged at different positions directly on the measurement sensor on the one hand and on the base body on the other hand.

A particularly preferred development of the measuring head is characterised in that the or each measurement sensor is configured and adapted to be in contact with an inner surface of a circular knife. This configuration, in particular the shape of the measurement sensors and the spring-loaded action of the thin spring steel sheets as the measurement sensors, which can be tensioned between the circular knives, ensures that the measurement sensors are positioned in a space-saving manner between inner surfaces, which are turned towards one another, of the circular knives for performing the belly cut, and that they are in contact therewith.

The object is also achieved by a working station having the features referred to at the outset in that the measuring head is configured and adapted as disclosed herein. The resulting advantages have already been described in connection with the measuring head, so reference will be made to the above statements to avoid repetition. The circular knives are in a V shape with respect to one another. Moreover, the circular knives are directed towards one another in the opposite direction to the transport direction T. As a result, the distance between the circular knives on the incoming side is smaller than the distance between the circular knives on the outgoing side, such that the point at which the distance between the cutting edges of the circular knives is the smallest is located upstream of the axes of rotation of the circular knives in the transport direction T. The distance becomes increasingly larger downstream of the axes of rotation of the circular knives in the transport direction T.

Advantageously, in every position, the measurement sensors of the measuring head are in close contact with the inner surfaces, which are turned towards one another, of the circular knives at least in part, namely at least by their probe tip. Since the measurement sensors are in close contact with the inner surfaces of the circular knives with a slight pressure, the distance between the measurement sensors is substantially the same as the distance between the circular knives in every position.

A preferred embodiment is characterised in that, in the standby position, the measurement sensors with their probe tips point in the opposite direction to the transport direction T and protrude beyond the cutting edges of the circular knives, on the one hand, and are located in the transport direction T upstream of the point at which the distance between the circular knives is the smallest, on the other hand. The probe tips of the measurement sensors can pivot within a pivot range out of the standby position, in which the probe tips are directed in the opposite direction to the transport direction T, protrude beyond the cutting edges of the circular knives and are located in the transport direction T upstream of the axes of rotation of the circular knives and also still upstream of the point at which the distance between the circular knives is the smallest, into the measuring position, in which the sensing lugs trigger the sensor and the probe tips are located in the cutting shadow of the circular knives. The cutting shadow describes the region in which the probe tips are located below the cutting edges of the circular knives and downstream of the axes of rotation of the circular knives in the transport direction T, i.e. in a region in which the distance between the circular knives is greater than in the region where the distance between the circular knives is the smallest. Since in every position the measurement sensors are in contact with the inner surfaces, which are turned towards one another, of the circular knives at least in part, i.e. at least always by their probe tips, it is ensured on the one hand that the measurement sensors are securely taken by the flank bones in the standby position and on the other hand that the fish can be released in the measuring position without any collisions. The measurement sensors are thus in contact with the inner surfaces of the circular knives, which are turned towards one another, at least by their probe tips in the standby position, in the measuring position and also when pivoting from one position into the other. During the pivoting, the measurement sensors are moved with their probe tips on the one hand in the transport orientation of the fish, i.e. in the transport direction and in the opposite direction to the transport direction T. During the pivoting, however, they are also moved transversely to the transport direction T at least by their probe tips. In the standby position, the distance between the measurement sensors is approximately the same as the distance E between the circular knives. The distance reduces in the transport direction T at the point P of the smallest distance down to the distance S, at which the circular knives are engaged with the fish, and then increases in the transport direction T to a distance A when the measurement sensors are in the measuring position, with A being greater than E. The close contact means that each measurement sensor is in contact with the circular knives in a curved manner following the contour thereof, and namely with a slight (spring) pressure, in particular even when moving out of the standby position into the measuring position, since the measurement sensors are flexible and pliable.

Particularly advantageously, the knife assembly is configured and adapted for performing a belly cut on a slaughtered, beheaded and gutted fish being transported head-end first in the transport direction T. In other words, the measuring head and the knife assembly for performing the belly cut form a unit. Since the measuring head is assigned to the knife assembly for performing the belly cut, the length of the abdominal cavity can be established at the earliest possible time, at which the fish is still stable. Before or during the belly cut, in relation to the abdominal cavity, longitudinally the fish either are still closed, i.e. with the belly skin closed, or, in particular with larger fish, are open, i.e. with the belly skin slit. In that case, however, at least the flank bones are still rigidly connected to the backbone so as to give the fish the required stability. The combination of the knife assembly for performing the belly cuts with the measuring head, i.e. the assignment of the measuring head between the circular knives for performing the belly cuts, ensures that a measurement is carried out on a stable fish body; this likewise means that a greater probing force can be applied, which in turn means that the influence of potential interfering bodies can be significantly reduced. By forming a working station in which the measuring head operates in the region of the circular knives for performing the belly cuts, after the measurement signal has been triggered each measurement sensor can move out of the fish in the belly cut performed during the measurement or after the measurement, without getting caught on the abdominal cavity and/or on the belly skin. This reduces the dragging travel, i.e. the movement of each measurement sensor out of a standby position into the measuring position and back, leading to higher dynamic performance of the measuring head.

The object is also achieved by an apparatus having the features referred to at the outset in that the working station is configured and adapted as disclosed herein. The resulting advantages have already been described in connection with the measuring head and working station, so reference will be made to the above statements to avoid repetition.

Expediently, a plurality of working stations are arranged along the transport path and are arranged downstream of the working station as disclosed herein the transport direction T. Further working stations are in particular knife assemblies for performing flank cuts, flank bone cuts, backbone cuts, pin bone or belly flap cuts, and separating cuts.

Preferably, the apparatus comprises a control unit that is configured and adapted for controlling the working stations on the basis of the measurement data established by the measuring head as disclosed herein, the control unit comprising at least an evaluation unit and a storage device. The control device of the measuring head can be configured separately or be part of the control unit of the apparatus. These knife assemblies, which perform size-dependent filleting cuts, i.e. in particular the knife assemblies for performing the flank cuts and for performing the pin bone or belly flap cuts, can be controlled on the basis of the measurement data that are established by the measuring head in the region of the knife assembly for performing the belly cut and evaluated. In particular, the control device or control unit is configured and adapted to control when the circular knives for performing the flank cuts are engaged with the fish at the beginning of the abdominal cavity and disengaged therefrom at the end of the abdominal cavity, and when and with which cutting curve the circular knives for performing the pin bone or belly flap cuts along the pin bone line are controlled.

Moreover, the object is achieved by a method having the steps referred to at the outset in that the position of the closest flank bones of the fish to the anus of the fish is established by means of the measuring head and the size of the fish is calculated therefrom in order to control the knife assembly for performing the flank cuts. On the basis of the last flank bones located before the anus, a particularly exact position signal can be picked up in order to determine the length of the abdominal cavity and thus the size of the fish. With this knowledge, the knife assemblies altogether, and in particular the knife assemblies for performing the flank cuts, can be controlled particularly precisely. The resulting further advantages have already been described in connection with the measuring head, the working station and the apparatus, so reference will be made to the above statements to avoid repetition.

Advantageously, the measurement data are established before the belly cut or during the belly cut while it is being performed. Determining the measurement data at this early time in the filleting process is particularly precise since the fish is still very stable and high probing forces are accordingly possible, such that the influence of interfering bodies and the like can be reduced. Since the measurement takes place before or during the belly cut, the measurement sensors can then be moved out of the fish without any collisions.

Preferably, as a result of the fish being transported in the transport direction T, the closest flank bones to the anus on both sides of the backbone bump against measurement sensors arranged on both sides of the backbone and, as the fish is transported further, deflect said measurement sensors until the measurement sensors trigger a sensor by a sensing lug. The measurement signals are relayed to a control device or control unit, by means of which they are processed and optionally stored. The control device or control unit then controls the or each knife assembly that performs the filleting cuts, for which the size of the fish is relevant.

Particularly preferably, at least the knife assembly for performing the pin bone or belly flap cuts is also controlled on the basis of the measurement data established by the measuring head. As a result, cuts can be made precisely along the specific pin bone line using the circular knives.

Especially preferably, the method is carried out using an apparatus as disclosed herein.

DETAILED DESCRIPTION OF THE INVENTION

The measuring head shown in the drawing is suitable for use between two circular knives of a knife assembly for performing a belly cut on slaughtered, beheaded and gutted fish being transported head-end first, in order to establish the length of the abdominal cavity. It goes without saying that the measuring head is also suitable for being positioned between circular knives of other knife assemblies for performing filleting cuts. In all cases, the measuring head is configured and adapted for generating measurement signals on the basis of which the circular knives or knife assemblies are controlled.

The measuring head10is configured and adapted for determining the length of the abdominal cavity11of a slaughtered, beheaded and gutted fish12being transported head-end first in the transport direction T, and comprises at least one measurement sensor13and at least one sensor14, which can be triggered by the measurement sensor13and is connected to a control device15, which is configured and adapted for picking up and processing the incoming measurement signals.

According to the invention, this measuring head10is characterised in that the measuring head10is configured and adapted at least partly for being positioned between two circular knives16,17of a knife assembly18for performing a filleting cut on the fish12, in such a way that the or each measurement sensor13can be operatively connected to a flank bone20of the fish12that is closest to the anus19of the fish12.

Whether taken on their own or in combination with each other, the features and developments described below illustrate preferred embodiments. It is explicitly noted that features combined in the claims and/or the description and/or the drawings or described in a common embodiment can also refine the above-described measuring head10in a functionally independent manner.

The measuring head10comprises a base body22that can be fastened to a machine frame21in a stationary manner, at least one measurement sensor13being arranged on the base body22in a rotatably mounted manner. In the embodiment shown, this base body22is formed in the manner of a jib and comprises a fastening arm23and a supporting arm24on which the or each measurement sensor13is arranged in a rotatably mounted manner. The fastening arm23is assigned to the machine frame21. The fastening arm23and supporting arm24are preferably formed in one piece and are preferably made of a stainless steel. An embodiment that is not shown comprises a single measurement sensor13. The drawing shows an embodiment in which the measuring head10comprises two measurement sensors13,25that are arranged at a distance from one another on opposite sides of the supporting arm24. The two measurement sensors13,25, which are formed separately from one another, are mounted so as to be rotatable about the axis of rotation D, on a spindle26that is mounted in the supporting arm24.

Both measurement sensors13,25are made of a thin, flexible spring steel sheet. The thickness of the spring steel sheets depends on different factors, including the size of the fish to be measured, and is preferably less than 1 mm and particularly preferably less than 0.5 mm. Each measurement sensor13,25or each spring steel sheet comprises a main body27. The main body27is formed in a planar, sheet-like manner and has openings or material-free apertures28and clearances29in its surface. At least one probe tip30is assigned to each main body27. The probe tip30is formed in one piece with the main body27and points in the opposite direction to the transport direction T when the measuring head10is in a standby position (see e.g.FIG.4). The probe tip30tapers in the opposite direction to the transport direction T. The free end31of the probe tip30is upstream of the axis of rotation D of the measurement sensors13in the transport direction T when the measuring head10is in the standby position. In a measuring position, the free end31of the probe tip30is downstream of the axis of rotation D of the measurement sensors13in the transport direction T.

In addition to the probe tip30, the main body27has at least one sensing lug32, which can be operatively connected to the sensor14. The sensing lug32is formed in one piece with the main body27and is downstream of the axis of rotation D of the measurement sensors13in the transport direction T in both the standby position and the measuring position, the sensing lug32fully uncovering the sensor14in the standby position and covering it at least partly, preferably entirely, in the measuring position.

In addition to the (indirect) connection between the two measurement sensors13,25by means of the shared spindle26, the two measurement sensors13,25arranged at a distance from one another and rotatably mounted on the supporting arm24are interconnected by means of a cross-brace33at least at one point. A first cross-brace33is formed upstream of the axis of rotation D of the measurement sensors13,25in the transport direction T of the fish being processed, the cross-brace33being formed by a bolt34that is releasably fastened to both measurement sensors13,25and is oriented transversely to the transport direction T. An adjustability is provided as regards the position at which the bolt34is fastened in relation to the axis of rotation D. In the main bodies27of the spring steel sheets, bores35are formed at different positions such that the cross-brace33can be secured at different positions.

A second cross-brace36is formed downstream of the axis of rotation D of the measurement sensors13,25in the transport direction T of the fish12being processed, the cross-brace36being formed by a bolt37that is releasably fastened to both measurement sensors13,25and is oriented transversely to the transport direction T. The bolt37connects the two measurement sensors13,25in the region of a fastening lug38, which belongs to the main body27and is formed in one piece with the main body27. The second cross-brace36interacts with a stop element39arranged on the main body22. The stop element39is, for example, an adjustable bolt40by means of which the length of the pivot range of the measurement sensors13,25is limited. The length of the pivot range can be adjusted by the adjustability of the bolt40or any other stop means. In the end position of the pivot range, which constitutes the measuring position, the sensing lug32covers the sensor14in such a way as to trigger a measurement signal. In the embodiment shown, the sensor14(formed in this case by way of example as a proximity sensor) is arranged indirectly on the fastening arm23of the base body22. Namely, the sensor14is assigned to an adjustment plate41that is arranged on the base body22, namely on the fastening arm23, in a releasable and adjustable manner.

The measurement sensors13,25are basically held in a standby position in a spring-biased manner (see e.g.FIG.4), a spring element42being tensioned between the or each measurement sensor13,25and the base body22. The spring element42is fastened to the first cross-brace33by one end. The spring element42is fastened to the supporting arm24by the opposite end. For this purpose, an ear43is arranged on the supporting arm24, on which ear the spring element42is arranged. The measurement sensors13,25are configured and adapted so as to be deflectable out of said standby position (shown, for example, inFIG.4) into a measuring position (shown, for example, inFIG.5) counter to the spring force of the spring element42. In the measuring position, the sensing lug32covers the sensor14at least in part.

A cover/protection element44is arranged on the supporting arm24of the base body22in the extension of the supporting arm24. The cover/protection element44is a kind of protective plate that substantially covers the first cross-brace33and thus protects the spring element42in particular. The width of the protective plate extends from an inner side45of the first measurement sensor13to the opposite inner side46of the second measurement sensor25and can additionally serve as a guide and spacer for the pliable, flexible measurement sensors13,25.

As described above, each measurement sensor13,25is formed from a spring steel sheet in an elastically deformable manner. As a result, the measurement sensors13,25are configured and adapted for being in contact with an inner surface47,48of a circular knife16,17. This configuration and adaptation of the measurement sensors13,25is particularly applicable in the operative connection to the circular knives16,17as part of the working station49described below.

The measuring head10can be used as a separate unit, in particular also as a retrofit kit for existing systems. Preferably, however, the measuring head10is part of a working station49. This working station49is configured and adapted for processing slaughtered, beheaded and gutted fish12and comprises a knife assembly18having two cutting heads51,52, each of which comprises a circular knife16,17that can be rotationally driven and a drive unit53,54for rotationally driving the circular knife16,17, the two circular knives16,17being oriented in a manner tilted in a V shape with respect to one another and being oriented in a manner tilted towards one another in the opposite direction to the transport direction T of the fish12being processed, and comprises a measuring head10for determining the length of the abdominal cavity11of a slaughtered, beheaded and gutted fish12.

According to the invention, the working station49is characterised in that the measuring head10is configured and adapted as disclosed herein.

The two circular knives16,17are arranged on opposite sides of the fish12being processed and are accordingly arranged at a distance from one another. The distance between the two circular knives16,17is less than the distance between the two measurement sensors13,25at least in some portions, in particular owing to the tilt of said circular knives with respect to one another in the opposite direction to the transport direction T, and so the circular knives16,17push the two measurement sensors13,25into their position transversely to the transport direction T owing to the arrangement of said measurement sensors between the two circular knives16,17. In every position, the measurement sensors13,25of the measuring head10are in close contact with the inner surfaces47,48, which are turned towards one another, of the circular knives16,17namely at least in part, namely at least by their probe tip30. Owing to the spring-loaded configuration and adaptation of the measurement sensors13,25, they are in contact with the inner surfaces47,48, which are turned towards one another, of the circular knives16,17with a slight pressure. This close contact between the measurement sensors13,25and the inner surfaces47,48of the circular knives16,17with a slight pressure means that each measurement sensor13,25is in contact with the circular knives16,17in a curved or arcuate manner following the contour and tilt thereof, in particular even when moving out of the standby position into the measuring position. In principle, the distance between the circular knives16,17is also the same as the distance between the measurement sensors13,25. In the standby position, the distance between the measurement sensors13,25is approximately the same as the distance E between the circular knives16,17. The distance reduces in the transport direction T at the point P of the smallest distance down to the distance S, at which the circular knives16,17are engaged with the fish12, and then increases in the transport direction T to a distance A when the measurement sensors13,25are in the measuring position, with A being greater than E (see e.g.FIG.6).

Owing to the V-like position of the circular knives16,17and their tilt towards one another in the opposite direction to the transport direction T, on the one hand, and owing to the position of the measurement sensors13,25in close contact with the inner surfaces47,48of the circular knives16,17with a slight pressure, on the other hand, the measurement sensors13,25in the standby position can be entrained by the last flank bones20before the anus19of the fish12in order to trigger the sensor14in the measuring position, in which they are in the cutting shadow of the circular knives16,17. In this case, the configuration according to the invention ensures that the measurement sensors13,25can be freed of potential debris, in particular since the measurement sensors13,25are in the cutting shadow when in the measuring position. As shown inFIG.4for example, in the standby position, the measurement sensors13,25with their probe tips30point in the opposite direction to the transport direction T and protrude beyond the cutting edges55,56of the circular knives16,17, on the one hand, and are located in the transport direction T upstream of the point at which the distance S between the circular knives16,17is the smallest on the other hand.

In the embodiment shown, the knife assembly18is configured and adapted for performing a belly cut on a slaughtered, beheaded and gutted fish12being transported head-end first in the transport direction T. By assigning the measuring head10to the knife assembly18for performing the belly cut, the measurement can be carried out at the earliest possible time in the filleting operation, and specifically on a stable fish12since the regions and bones supporting the body of the fish12have not yet been cut. In addition, the measurement can even be carried out on fish12that longitudinally are still closed in relation to the abdominal cavity, i.e. have closed belly skin. Since the measurement sensors13,25are arranged in the region of the circular knives16,17for performing the belly cut, the measurement sensors13,25can be moved out of the fish12once the last flank bones20before the anus19of the fish12have been probed, without getting caught in the abdominal cavity11or on the belly skin.

Preferably, the working station49is part of an apparatus57that is configured and adapted for processing, in particular filleting, slaughtered, beheaded and gutted fish12, comprises a transport device58for holding and transporting the fish12head-end first in the transport direction T along a transport path and comprises at least one working station49along the transport path for processing the fish12.

According to the invention, the apparatus57is characterised in that the working station49is configured and adapted as disclosed herein. In the embodiment shown, a plurality of working stations59,60,61,62,63are arranged along the transport path and are arranged downstream of the working station49in the transport direction T. In the view shown according toFIG.7, the working stations59to63are knife assemblies for performing flank cuts (knife assembly67), flank bone cuts (knife assembly68), backbone cuts (knife assembly69), pin bone or belly flap cuts (knife assembly70), and separating cuts (knife assembly71).

The fish12being processed are transported from working station49to working stations59to63by means of the transport device58. In the embodiment shown, two spike chains64,65driven in a circulatory manner and guided around deflection and/or drive elements are preferably used as the transport device58. The spike chains64,65grip the fish12on both sides and hold it during the transport along the transport path. Other transport systems, belts or conveyors having corresponding holding elements for the fish12can also be used.

The apparatus57comprises a control unit66that is configured and adapted for controlling the working stations49,59to63on the basis of the measurement data established by the measuring head10, the control unit66comprising at least an evaluation unit and a storage device. The control device15of the measuring head10can be formed separately from the control unit66of the apparatus57or be part of the control unit66. The knife assemblies67to71can be controlled on the basis of the established and evaluated measurement data of the measuring head10. In particular, the knife assembly67for performing the flank cuts can be controlled, i.e. as to when the circular knives for performing the flank cuts are engaged with the fish12at the beginning of the abdominal cavity11and disengaged therefrom at the end of the abdominal cavity11, and the knife assembly70for performing the pin bone or belly flap cuts can also be controlled, i.e. as to when and with which cutting curve the circular knives for performing the pin bone or belly flap cuts along the pin bone line are controlled.

The method is explained in greater detail below with reference to the drawing.

The method is used for processing, in particular filleting, slaughtered, beheaded and gutted fish12. For this purpose, the fish12are fed head-end first to at least two working stations49,59for working the fish12by means of a transport device58in the transport direction T. Processing cuts, namely filleting cuts, are successively performed at the working stations49,59. The filleting cuts are performed on the fish12being processed by means of knife assemblies18,67as working stations49,59, by successively transporting the fish12being processed along two rotationally driven circular knives16,17of a knife assembly18,67. As a first filleting cut, a belly cut is performed using a first knife assembly18, followed at least by a flank cut using a second knife assembly67arranged downstream of the first knife assembly18in the transport direction T. At least the knife assembly67for performing the flank cuts is controlled on the basis of measurement data, established by means of a measuring head10, regarding the size of the fish12.

According to the invention, the position of the closest flank bones20of the fish12to the anus19of the fish12is established by means of the measuring head10, and the size of the fish12is calculated therefrom in order to control the knife assembly67for performing the flank cuts. The measurement signals or measurement data are evaluated in the control device15or control unit66, and the or each knife assembly67is controlled on the basis of the thus established length of the abdominal cavity11or size of the fish12. In relation to the knife assembly67for performing the flank cuts, this means that the circular knives cut into the fish12right at the start of the abdominal cavity11and are moved out of the fish12, or at least covered, at the end of the abdominal cavity11so that the circular knives of the knife assembly67do not make any further cuts.

Ideally, the measurement data are established before the belly cut or during the belly cut while it is being performed. In this case, as a result of the fish12being transported in the transport direction T, the closest flank bones20to the anus19on both sides of the backbone bump against measurement sensors13,25arranged on both sides of the backbone and, as the fish is transported further, deflect said measurement sensors until the measurement sensors13,25trigger a sensor14by a sensing lug32. Thus, position signals are obtained and are processed to establish the length of the abdominal cavity11of the fish12. Said control data derived therefrom are used for all the knife assemblies59to71that perform size-dependent filleting cuts. In addition to the flank cuts, at least the knife assembly70for performing the pin bone or belly flap cuts is also controlled on the basis of the measurement data established by the measuring head10. It goes without saying that the measurement data established by the measuring head10before or during the belly cut can also be used to control the further knife assemblies68,69,71.

Preferably, the method is carried out using an apparatus57.

During the measuring, i.e. in particular even when the measurement sensors13,25are pivoted out of the standby position into the measuring positionand also back againthe measurement sensors13,25slide on the inner surfaces47,48of the circular knives16,17. Preferably, a fluid, in particular water, is fed into the region in which the measurement sensors13,25are in contact with the circular knives16,17via suitable inlets, nozzles or the like, so that the measurement sensors13,25slide on the inner surfaces47,48of the circular knives16,17in an almost hydrodynamic manner.