DK178303B1

DK178303B1 - A fish processing machine and a method for processing fish

Info

Publication number: DK178303B1
Application number: DKPA201470272A
Authority: DK
Inventors: Ivan Kristensen; Daniel Braad Jørgensen
Original assignee: Kroma As
Priority date: 2014-05-05
Filing date: 2014-05-05
Publication date: 2015-11-23
Also published as: DK201470272A1; WO2015169320A1

Abstract

Disclosed is a fish processing machine (1) for gutting fish (3). The fish processing machine (1) comprises one or more fish processing means (2) including pressing means (4) for pressing a fish processing tool (5) against or into the fish (3) with a certain contact pressure at least during a part of a fish processing process. The fish processing machine (1) also comprises control means (6) arranged to receive input at least corresponding partly to a rigidity value of the fish (3), wherein the control means (6) is arranged to adjust the contact pressure in accordance with the input. A method for processing fish (3) by means of a fish processing machine (1) is also disclosed.

Description

A FISH PROCESSING MACHINE AND A METHOD FOR PROCESSING FISH Field of the invention

The invention relates to a fish processing machine for gutting fish and a method for processing fish by means of a fish processing machine.

Background of the invention

Immediately after death the muscles of a fish are soft and limp, and can easily be flexed but after a while the muscles begin to stiffen and harden as the fish enters rigor mortis. After some hours or days the fish exits the rigor mortis state as the muscles gradually begin to soften and become limp again. However in this post rigor mortis state the cohesion of the fish tissue is now reduced.

With manual fish processing this is not a particular problem but with automated processing of fish where the fish is processed - i.e. cut open, gutted, cleaned and/or other - in an automated process, it can be very problematic that the rigidity and the cohesion of the fish tissue is not constant, in that automated processes adapted for processing fish in pre-rigor mortis state or a rigor mortis state might damage a fish in post rigor mortis state.

From US 4,827,571 it is known to clean fish by means of brushes having different predetermined holddown forces. But this technique is space consuming and inefficient.

An object of the invention is therefore to provide for an advantageous technique for processing fish.

The invention

The invention provides for a fish processing machine for gutting fish. The fish processing machine comprises one or more fish processing means including pressing means for pressing a fish processing tool against or into the fish with a certain contact pressure at least during a part of a fish processing process. The fish processing machine also comprises control means arranged to receive input at least corresponding partly to a rigidity value of the fish, wherein the control means is arranged to adjust the contact pressure in accordance with the input.

Controlling the contact pressure - of fish processing means comprising means pressing against or into the fish - in relation to a rigidity value of the fish is advantageous in that it hereby is possible to increase the contact pressure when the fish is more rigid and reduce the contact pressure when the fish is more soft - thus, adapting operation to the specific state of the fish and thereby reduce the risk of pressure applied to the fish - by the fish processing means - will damage the fish and reduce its value.

The term “pressing means” is in this context to be understood as any kind of active mechanical actuator such as a hydraulic cylinder, a pneumatic cylinder, a motor, a linear electrical actuator or other and/or any kind of passive means capable of applying pressure such as a spring or any other kind of elastic or resilient member or contraption or any combination thereof or any other kind of pressing device suited for pressing a fish processing tool against or into a fish.

In an aspect of the invention, said input regarding rigidity values of said fish is at least partly established on the basis on one or more rigidity sensors arranged to detect the rigidity of one or more of said fish.

Establishing the rigidity values by means of rigidity sensors is advantageous in that it hereby is possible to fully automate the fish processing and it is possible to adjust the contact pressure in relation to more precise and/or reliable rigidity values.

The term “rigidity sensor” is in this context to be understood as any kind of infrared sensor, camera, ultrasound sensor, stiffness senor, hardness sensor or any other kind of sensor or combination of sensors suited for determining a value in relation to the rigidity of the fish and particularly the cohesion of the fish tissue by means of some sort of measurement or testing of the fish.

In an aspect of the invention, said input regarding rigidity values of said fish is at least partly established on the basis on manual input.

Establishing the rigidity values on the basis on manual input is advantageous in that it simplifies the fish processing machine and thereby reduces its cost.

In an aspect, said fish processing means comprising pressing means are arranged to operate at at least a high contact pressure and a low contact pressure and wherein said high contact pressure is between 5% and 300%, preferably between 10% and 200% and most preferred between 20% and 100% higher than said low contact pressure.

If the high contact pressure is too high in relation to the low contact pressure the risk of damage to the fish tissue is increased and if the high contact pressure is too low in relation to the low contact pressure the risk of malfunction or undesired displacement (e.g. poor fixation) of the fish is increased. Thus, the present pressure relationships present an advantageous relationship between fish quality and machine functionality.

In an aspect, said pressing means comprises pneumatic cylinders and wherein said contact pressure is adjusted by adjusting a supply air pressure.

Pneumatic cylinders provides simple and inexpensive means for creating a pressing motion and is for this and other reasons advantageous for use in relation with processing food such as fish.

In an aspect, a general supply air pressure of said fish processing machine is arranged between 6-8 Bar and wherein said pressing means is arranged to operate at at least a high contact pressure being substantially identical with said general supply air pressure and a low contact pressure arranged between 3-5 Bar.

Making the high contact pressure substantially identical with the general supply air pressure is advantageous in that substantially no adjustment of the contact pressure is needed when operating at high contact pressure. Furthermore, if the low contact pressure is too low some of the fish processing machine’s functions may not function properly and it is therefore advantageous that the low contact pressure is between 1-5 Bar lower than the high contact pressure.

In an aspect, said fish processing machine comprises an interface through which inputs regarding said rigidity value of said fish may be delivered manually.

In one embodiment the rigidity value of the fish could be obtained in a dedicated testing station, in another machine, by means of handheld measuring equipment, by means of manual observations of the fish or conditions regarding the fish or through other means more or less independent from the fish processing machine and it is therefore advantageous that the fish processing machine comprises an interface through which an input corresponding to a rigidity value of the fish may be provided to the control means.

In an aspect, said one or more fish processing means comprises one or more brushing means for brushing blood or entrails remains out of the abdomen of said fish.

Using brushing means is a fast and efficient way of cleaning a fish but brushing means is also relatively hard on the fish tissue due to high friction. Thus, it is particularly advantageous to use the present invention in relation with fish processing means comprises one or more brushing means.

The term “brushing means” is in this context to be understood as any kind of rotating and/or reciprocating brush e.g. formed by straws, sticks, pins, hairs, foam, rubber or any other kind of material suitable for use when cleaning a fish.

In an aspect, said brushing means comprising a brushing body for performing the brushing process and brushing displacement means for pressing said brushing body against an inside surface of said fish at said certain contact pressure at least during a part of said brushing process.

Hereby is achieved an advantageous embodiment of the invention.

In an aspect, said one or more fish processing means comprises one or more oesophagus severing means, a kidney cutting and suction device, fixation means and/or a gill severing device.

Oesophagus severing means, a kidney cutting and suction device, fixation means and a gill severing device all comprises some kind of pressing means for pressing some kind of fish processing tool against or into the fish and it is therefore particularly advantageous to use the present invention in relation with a fish processing machine comprising one or more of these fish processing means.

The term “fixation means” should in this context be understood as any kind of hook, clamp, cart or similar fixation device suitable for fixating the head of a fish.

In an aspect of the invention, said control means is arranged to adjust said contact pressure between two or more predefined contact pressure levels in accordance with said input.

Adjusting the contact pressure stepless in relation to the rigidity value might reduce the risk of damaging the fish slightly but it will also complicate the machine design thus increase cost. It is therefore advantageous to adjust the contact pressure between two or more predefined contact pressure levels in accordance with the input regarding rigidity values.

The invention further provides for a method for processing fish by means of a fish processing machine for gutting fish. The method comprising the steps of: • detecting a rigidity value of the fish, • providing an input to control means of the fish processing machine in accordance with the rigidity value, and • adjusting a contact pressure of pressing means of one or more fish processing means in accordance with the input, wherein the pressing means comprises means for pressing a fish processing tool against or into the fish.

Adjusting the contact pressure of one or more fish processing means in accordance with input relating to a rigidity value of said fish is advantageous in that the risk of the fish processing means damaging soft fish tissue is hereby reduced.

In an aspect of the invention, said contact pressure is adjusted between two or more predefined contact pressure levels in accordance with said input.

Adjusting the contact pressure between two or more predefined contact pressure levels - in accordance with the rigidity value input - is advantageous in that it provides for a more simple and inexpensive fish processing machine design.

In an aspect of the invention, said input is provided to said control means at least partly by means of one or more rigidity sensors detecting the rigidity of one or more of said fish.

In an aspect of the invention, said input is provided at least partly by means of manual input to said control means.

In an aspect of the invention, said rigidity value of said fish is detected by manual inspection of said fish.

Sometimes the rigidity value of the fish can simply be obtained through knowledge regarding how long ago the fish was caught or killed, the specific fish species, storage conditions or other and particularly a combination of two or more of these factors and in these cases it would be inexpensive and simple to establish the rigidity value of the fish by means of manual inspection of the fish.

In an aspect, said method further comprises adjusting a contact pressure of oesophagus severing means, a vein cutting and suction device and/or a gill severing device of said fish processing machine in accordance with said input.

In an aspect of the invention, said method is a method for processing fish by means of a fish processing machine according to any the previously mentioned fish processing machines.

Figures

The invention will be described in the following with reference to the figures in which fig. 1. illustrates a fish processing machine, as seen in perspective, fig. 2 illustrates cross section through the middle of a first fish processing machine part, as seen from the front, fig. 3 illustrates cross section through the middle of a second fish processing machine part, as seen from the front, and fig. 4 illustrates a simplified pneumatic diagram of a fish processing machine.

Detailed description

Fig. 1 illustrates a fish processing machine 1, as seen in perspective.

In this embodiment the fish processing machine 1 first comprises an input station 22 on which the fish 3 is manually placed. By means of the main conveyer 24 the fish 3 is drawn into the first fish processing machine part 20 in which the throat and abdomen 12 is cut open before the fish 3 exits the first fish processing machine part 20 to enter the entrails removal station 23. At the entrails removal station 23 the entrails is in this case manually removed to protect the spawn - which can be a valuable commodity - but particularly out of season where the fish 3 do not contain spawn the entrails could be automatically removed e.g. by means of suction. From the entrails removal station 23 the fish 3 enters the second fish processing machine part 21 in which the kidney is removed and the inside of the fish is cleaned by brushing means 13 before the gutted fish 3 exits the fish processing machine 1.

The first fish processing machine part 20 and the second fish processing machine part 21 will be discussed in more details in relation with fig. 2 and fig. 3.

Furthermore, it should be noted that the present embodiment of a fish processing machine 1 is only one of many embodiments of fish processing machines 1 where the present invention could advantageously be used - e.g. in another embodiment one or more of the stations 22, 23 and/or parts 20, 21 could be provided with their own individual conveyer, in another embodiment one or more of the stations 22, 23 and/or parts 20, 21 could be absent or formed integrally with another station 22, 23 or part 20, 21. Also, in the following the specific fish processing means 2 of the present embodiment of a fish processing machine 1 will discussed in more details but it is evident to the skilled person that in another embodiment one or more of these fish processing means 2 could be designed differently both visually and mechanically, one or more of these fish processing means 2 could be omitted, one or more of these fish processing means 2 could be replaced by other fish processing means 2 or more fish processing means 2 could be added and they could be arranged differently.

In this embodiment, the main conveyer 24 and all the fish processing means 2 are lined up and arranged so that the longitudinal direction of the fish 3 are arranged substantially parallel with the transport direction - i.e. in this embodiment the fish 3 are substantially arranged head to tail through the machine 1. However, in another embodiment the fish processing means 2 and the main conveyer 24 could be so designed and arranged so that the fish 3 would be transported and processed while being arranged parallel side by side - i.e. the longitudinal direction of fish 3 would be arranged substantially perpendicular with the transport direction of the main conveyer 12. In such a configuration identical fish processing means 2 could be arranged side by side substantially perpendicular to operate substantially synchronously e.g. to increase the capacity of the fish processing machine 1.

By the term “longitudinal direction” is to be understood the direction defined by the length of the fish 3 i.e. the length measured from head of the fish 3 to the tail fin of the fish 3.

In another embodiment some or all fish processing means 2 could also be arranged to engage the fish 3 at an underside of the main conveyer 24.

In this embodiment most of the fish processing means 2 comprises some kind of pressing means 4 designed to press a fish processing tool 5 - such as a knife, a brush, fixation means or a suction device - against a surface or into a surface of the fish 3. In this case all the pressing means 4 are pneumatic cylinders. However, in another embodiment some or all the pressing means 4 could be another type of linear or rotary actuator, it could comprise rack and pinion, motors, springs, timing belts or other or any combination thereof.

In this embodiment the fish processing machine 1 is equipped with a rigidity sensor 7 arranged to detect the rigidity of at least one fish 3 before the first fish reaches the first processing means 2 that comprises pressing means 4. The control means 6 will then fix the contact pressure of the pressing means 4 according to the rigidity value measurement performed by the of rigidity sensor 7 for all the following fish 3 in a certain batch. However, the control means 6 could also be arranged to constantly or regularly adjust the contact pressure in response to constant or regular input from the rigidity sensor 7.

In this embodiment the front cover 29 of the second fish processing machine part 21 is provided with an interface 9 through which input regarding the rigidity of the fish 3 could be entered in another embodiment. This could e.g. be done by providing information regarding fish type, temperature, time of death and/or other, it could be done by entering measurements regarding the fish 3 rigidity obtained elsewhere e.g. by means of a handheld device, it could be done by choosing one of two or more predefined settings based on manual observations or evaluation of the fish 3 or it could be done in another way or any combination thereof.

The input will be delivered to control means 6 which in this embodiment is arranged at the back of the second fish processing machine part 21. In this embodiment the control means 6 is a PLC (Programmable Logic Controller) but in another embodiment the control means 6 could instead or also comprise a computer, a processor, a hardwired logical circuit or some other kind of control device capable of controlling the contact pressure directly or at least generate an output on the basis of which the contact pressure is controlled on the basis of input corresponding to some sort of rigidity value of the fish 3. In another embodiment the interface 9 could be integrated with the control means 6.

In this embodiment the interface 9 allows an operator to choose between two different settings e.g. “Rigid fish” or “Soft fish”. The operator will then e.g. inspect the fish 3 and if the operator then chooses “rigid fish” on the interface 9, the control means 6 will generate an output ensuring that all the fish processing means 2 that comprises pressing means 4 will operate at a high contact pressure level whereas if the operator chooses “Soft fish” the control means will generate an output ensuring that all the fish processing means 2 that comprises pressing means 4 will operate at a low contact pressure level. In this embodiment the high contact pressure is equal to the general supply air pressure of the machine - which in this case is 7 Bar - so if “Rigid fish” is chosen the pressing means 4 will in this case operate at 7 Bar. However in another embodiment the high contact pressure could be different from the general supply air pressure of the machine 1 i.e. the general supply air pressure could be 8 Bar and the high contact pressure could be 5, 6 or 7 Bar. If “Soft fish” is chosen the control means 6 will generate an output regulating the air pressure supplied to the pressing means 4 down to a low contact pressure which in this case is 3.5 Bar but in another embodiment it could be lower such as 2, 2.5 or 3 Bar or higher such as 4, 4.5 or 5 Bar.

In another embodiment the interface 9 could comprise further options to choose from - such as also “Medium rigid”, the contact pressure could be entered directly on the interface in response to rigidity values of the fish 3 e.g. manually converted via a conversion table or the rigidity value of the fish 3 could be provided to the control means 6 by means of the interface 9 in a number of other ways.

In another embodiment the control means 6 could be arranged to adjust the contact pressure on the basis of both input received from the interface 9 and input supplied from the rigidity sensor 7.

Fig. 2 illustrates cross section through the middle of a first fish processing machine part 20, as seen from the front.

In this embodiment the fish 3 is first erected and orientated by means of side brushes 25 so that the fish 3 is orientated with the abdomen 12 facing upwards before fixation means 17 on the main conveyer 24 fix the head of the fish 3 to the main conveyer 24.

The height of the abdomen 12 is now measured by means by an abdomen measuring device 27 after which a pair of collar bone detection arms 28 detects the collar bone of the fish 3 before a throat severing device 19 cuts open the throat of the fish 3. In the next station the oesophagus of the fish 3 is cut through the open throat by means of oesophagus severing means 15 before the abdomen 12 of the fish 3 is cut open by an abdomen cutting device 18 and the fish 3 leaves the first fish processing machine part 20.

Fig. 3 illustrates cross section through the middle of a second fish processing machine part 21, as seen from the front.

In this embodiment the first fish processing means 2 in the second fish processing machine part 21 comprises a kidney cutting device 16 which will tilt down and into the open abdomen 12 of the fish 3 to cut the kidney (also called a blood ribbon) -extending along the backbone of the fish 3 - and suck out the blood. After that follows three brushing means 11 which each individually comprises a brushing body - in this case in the form of a rotating brush - which is pressed against the inside of the fish 3 by means of brushing displacement means - i.e. pressing means 4 - which in this case is individually operating pneumatic cylinders. After the brushing means 11 the fish 3 reaches a decapitator 30 for cutting the head free of the body of the fish before the gutted fish 3 leaves the fish processing machine 1 while a disengage arm 31 aids in freeing the fish head from the fixation means 17.

It should be noted that on all illustrations the fish 3 is shown without a tail fin but in an embodiment of the invention the fish 3 would comprise its tail all the way through the fish processing machine 1 or the tail could be removed in the fish processing machine 1.

Fig. 4 illustrates a simplified pneumatic diagram of a fish processing machine 1.

In this embodiment the fish processing machine 1 comprises pressing means 4 of throat severing device 19, a pressing means 4 (i.e. brushing displacement means 14) of brushing means 11 and a pneumatic cylinder actuating the disengagement arm 31. However, it is obvious to the skilled person that in another embodiment the fish processing machine 1 would comprise more and/or other fish processing means 2.

In this embodiment the control means 6 comprises a number of pneumatic directional valves 32 of which two is connected to a high pressure air supply 33 and the other two valves are connected to a low pressure air supply 34. These four valves 32 will then supply pressurised air to the pressing means 4 of throat severing device 19 and the brushing means 11. The diagram also comprises a fifth valve connected to the pneumatic cylinder actuating the disengagement arm 31. This valve 32 is only connected to the high pressure air supply 33 but in another embodiment this valve could be connected to the general air supply 35 supplying air to both the high pressure air supply 33 and the low pressure air supply 34.

In this embodiment both the high pressure air supply 33 and the low pressure air supply 34 are provided with air pressure regulation means 36 enabling that the contact pressure of the high pressure air supply 33 and the low pressure air supply 34 can be regulated individually.

In this embodiment the high contact pressure is set at 6 Bar and the low contact pressure is set at 2 Bar and in this embodiment the two air pressure regulation means 36 are manually regulated but in another embodiment the air pressure regulation means 36 could be regulated by the control means and the air supplies 33, 34 could be set at different levels as previously discussed.

In another embodiment the high pressure air supply 33 could be formed by connecting the affected valves 32 directly to the general air supply 35 or the machine 1 could comprise further regulated air supplies enabling that fish processing means 2 and other parts of the machine would be able to operate at several different air pressure levels.

In this embodiment the control means receives input regarding a rigidity value of the fish 3 only from input on the interface 9 but as previously explained this input could also or instead be supplied by the rigidity sensor 7.

The disengagement arm 31 always operate at the same pressure so when the disengagement arm 31 needs to move, the control means 6 will change the setting of the valve 32 controlling the pneumatic cylinder actuating the disengagement arm 31 as needed independent of the specific rigidity value. However, when the pressing means 4 of the throat severing device 19 and the brushing means 11 needs to engage their respective fish processing tool 5 (see e.g. fig. 1) the control means will only activate the valves 32 connected to the low pressure air supply 34 when the input indicates that the fish 3 is soft and it will only activate the valves 32 connected to the high pressure air supply 33 when the input indicates that the fish 3 is rigid, thus ensuring that the pressing means 4 will operate at a high contact pressure when the fish 3 is rigid and at a low contact pressure when the fish tissue is more incoherent.

The invention has been exemplified above with reference to specific examples of fish processing machines 1, fish processing means 2, pressing means 4 and other.

List 1. Fish processing machine 2. Fish processing means 3. Fish 4. Pressing means 5. Fish processing tool 6. Control means 7. Rigidity sensor 8. Pneumatic cylinder 9. Interface 10.

11. Brushing means 12. Abdomen 13. Brushing body 14. Brushing displacement means 15. Oesophagus severing means 16. Kidney cutting device 17. Fixation means 18. Abdomen cutting device 19. Throat severing device 20. First fish processing machine part 21. Second fish processing machine part 22. Input station 23. Entrails removal station 24. Main conveyer 25. Side brush 26.

27. Abdomen measuring device 28. Collarbone detection arms 29. Front cover 30. Decapitator 31. Disengage arm 32. Pneumatic valve 33. High pressure air supply 34. Low pressure air supply 35. General air supply 3 6. Air pressure regulation means

Claims

1. Fish processing machine (1) for cleaning fish (3), the fish processing machine (1) comprises one or more fish processing products (2), which includes pressing means (4) for pressing a fish processing tool (5) toward or into the fish (3) with a certain contact pressure, at least during part of the fish processing process, and the control means (6) which is adapted to receive the input, which at least partly corresponds to a stiffness value for the fish (3), wherein the control means (6) is arranged to to regulate the contact pressure in accordance with the input.

2. Fish processing machine (1) in accordance with claim, wherein the input regarding stiffness values for the fish (3) at least in part is established on the basis of one or more stiffness sensors (7) which is adapted to detect the stiffness of one or more of the fish (3) .

3. Fish processing machine (1) in accordance with claim or 2, wherein the input regarding stiffness values for the fish (3) at least in part is established on the basis of manual input.

4. Fish processing machine (1) according to any one of the preceding claims, wherein the control means (6) is adapted to control the contact pressure between two or more pre-defined contact pressure levels in accordance with the input.

5. A method for processing fish (3) by means of a fish processing machine (1) for the purification of fish, the method comprising the steps of: • detecting a stiffness value for the fish (3), • providing an input to a control means (6) of fish processing machine (1) according to the stiffness value, and • adjustment of a contact pressure of a press agent (4) of one or more fish processing products (2) in accordance with the input where the pressing means (4) comprises a means for pressing a fish processing tool (5 ) against or into the fish (3).

6 A process according to claim 5, wherein the contact pressure is adjusted between two or more pre-defined contact pressure levels in accordance with the input.

7. The method of claim 5 or 6, wherein the input is provided to the control means (6) at least in part using one or more stiffness sensors which detect the stiffness of one or more of the fish (3).

8. A method according to claim 5 to 7, wherein the input is provided at least partially by means of manual input to the control means (6).

9. A method according to any one of claims 5 to 8, wherein the stiffness value of the fish (3) is detected by the manual inspection of the fish (3).

10. The method according to any one of claims 5 to 9, wherein the method is a method for processing fish (3) by means of a fish processing machine (1) according to any one of claims 1-4.