GB2032247A - Filleting fish - Google Patents

Abstract

A process for filleting unbeheaded fish (9) conveyed tail forward comprises performing belly filleting cuts, back filleting cuts and rib cuts. The fillets are cut free by severing cuts, performed after the rib cuts, extending closely behind the collar bone and inclined towards the roof of the skull, while leaving the collarbone and/or the head on the bone skeleton. An apparatus for filleting the fish comprises a conveyor (5) for the fish (9), a pair of belly filleting knives (21, 22), a pair of back filleting knives (31, 32) and a pair of rib knives (81, 82). The axes (83, 84) of the rib knives (81, 82) are arranged nearly parallel to each other and inclined in the feed direction of the conveyor (5). The rib knives (81, 82) are displaceable in the direction of their axes (83, 84) and are connected with control means to raise them at least on the arrival of the abdominal cavity end of each fish (9). <IMAGE>

Description

SPECIFICATION Filleting of fish The present invention relates to a process and apparatus for the filleting of fish.

NO-PS 124348 discloses a process for the beheading of the severing of the collar bones of fish conveyed in their longitudinal direction tail forward, by means of a pair of circular blades which are movable up and down and which are oblique to each other with their cutting edges against the feed direction of the fish.

The disclosed process has the advantage that a beheading machine is not required and personnel for loading a beheading machine with fish are therefore not needed. The process also has the advantage that a cutting location, which arises on the beheading of the fish at its head end and at which the danger of bacterial infection or mildew occurring exists with the intermediate storage of the fish before filleting, is not required. A disadvantage is that a special tool for the severing of the head or the collar bone and special measuring and control devices for the actuation of the tool are required for the performance of the process.Since the transport ofthefish pastthetool for the severing of the head takes place by means of a thrust saddle, smaller fish, the gill chambers of which are still disposed in the range of the thrust saddle, are not beheaded.

According to one aspect of the present invention there is provided a method of filleting unbeheaded fish, comprising the steps of performing bellyfilleting cuts, back filleting cuts and rib cuts on a fish while the fish is being advanced tail forward, the fillets being severed from the remainder of the fish after performing the rib cuts by so cutting the fish adjacent the collar bone and in a direction inclined towards the roof of the skull that at least one of the collar bone and the head remain on the fish.

Each rib cut may comprise an arcuate cut starting at the end of the abdominal cavity and a straight cut extending above the ribs or vertebral projections and continuing into the severing cut. Thereby, parting of the fillet from the bone skeleton behind the collar bone is made possible.

Each rib cut may extend from the belly flap above the flesh bones up to and beyond the collar bone as the severing cut. This obviates the need for special tools for severing cuts.

The rib cuts may enclose an angle of less than 1800 towards the belly side of the fish while leaving the thin parts of the belly lobes on the bone skeleton.

This make the economical production of fillets free of flesh bones possible, even from small fish.

According to another aspect of the present invention there is provided an apparatusforfilleting unbeheaded fish, comprising conveyor means to convey the fish, a pair of belly filleting knives, a pair of back filleting knives, a pair of rotatable rib cutting knives, and control means for the rib cutting knives, the axes of rotation of the rib cutting knives being almost parallel to each other and inclined in the conveying direction, each rib cutting knife being displaceable in a direction parallel to its axis of rotation and the control means being operable to displace the rib cutting knives in the direction of the dorsal side of the fish at least on the arrival of the abdominal cavity thereof.

Each rib cutting knife may be provided with a chamfer at the side thereof which in use faces the belly side of the fish.

Support means may be disposed upstream of the rib cutting knives. Thereby, the cutting effect of the rib cutting knives is restricted to the region of the abdominal cavity.

The conveyor means may comprise a plurality of saddle members each arranged to convey a respective fish and to actuate the control means. The control means may be actuated synchronously with the saddle tip. Thereby, control of the tip knives is made possible in a simple manner.

An embodiment of the present invention will now be more particularly described by way af example and with reference to the accompanying drawings in which Figure 1 shows an axonometric illustration of an apparatus embodying the present invention, Figure 2 shows a cross-section through the apparatus shown in Figure 1 at the level of the rib cutting knives, and Figure 3 shows a fish with cutting lines illustrated thereon.

Referring now to the accompanying drawings, a fish travels along a path 1, with its backbone co-inciding with the line, in the direction of the arrow indicated in the line. The path is disposed in a frame (not shown) of a filleting machine for fish. Disposed above and below the path 1 are respective pairs of rotatably driven belly filleting knives 21 and 22, back filleting knives 31 and 32 and severing knives 41 and 42. The fish is conveyed along the path 1 by means of thrust saddles 51, which are provided by way of example for different kinds of conveyors 5, such as tail clamps or endless entraining belts engaging at the flanks of the fish, and of which one 51 is illustrated.Downstream of and in the cutting plane of the pairs of belly filleting knives 21 and 22 and back filleting knives 31 and 32 are pairs of mutually inclined lower and upper bone guides 6 and 7 which engage into the belly and back filleting cuts and which each in the region oftheir upper and lower edges have gaps 61 and 71 for the passage of the belly and back spines respectively of the bone skeleton. Also there is a vertical gap 72 between them for the passage of the lateral vertebral projections or ribs. Between the pair of back filleting knives 31 and 32 and the pair of severing knives 41 and 42 is a rib cutter 8 comprising a pair of rib cutting knives 81 and 82 which are rotatable about axes 83 and 84 and which are displaceable axially.The axes include an angle 85 corresponding to the angle of inclination 73 of the upper bone guides 7. Each rib knife and its associated axis if also so inclined that the downstream portion 87 of the blade is lower than the upstream portion 88 and is so arranged that that portion of each blade 86 which faces the bone guides, in the lowermost setting of the respective circular knife lies just below the upper edges 62 of the lower bone guide 7 and almost touches the notionally downwardly projected outer surface 74 thereof. Upstream of each knife 81 and 82 is a cutting support 64 which is fast with the apparatus and which covers the upstream portion 88'of the peripheral edge of the knife 81 in the lowermost setting of the knives.Each of the knives 81 and 82 at its underside 89 has a bevel or chamfer 90 forming the peripheral edge 86 and is controlled in the height position of its cutting plane by control means (not shown) which are synchronised with the rotation of the conveying means and actuated in dependence on the setting of the entraining members of the conveyor.

The apparatus operates as follows: An unbeheaded, but degutted fish 9 is placed by its abdominal cavity on the saddle 51 of an endless circulating thrust saddle chain and conveyed by the saddle 51 to the pairs of belly filleting knives 21 and 22 and back filleting knives 31 and 32 which open the fish at its belly and back side by filleting cuts guided to both sides of the radii. The back filleting cuts can extend up to and through the skull of the fish, but they can be interrupted by driving out the backfilleting knives at the head end of the abdominal cavity.In its further advancing movement, the fish guided by means of the upper and lower bone guides 7 and 6, respectively, into the back and belly filleting cuts engages the knives 81 and 82 of the rib cutter 8, the effective circumferential edges 86 of which are, however, covered in their lower setting by the cutting supports 64 so that the fillet halves at the belly side are conducted away over the knives 81 and 82. By a suitable pulse on entry of the thrust saddle tip 52 into the region of the rib cutter 8, the rib knives 81 and 82 are displaced axially upwardly into a cutting plane, which selectably extends just above the certebral projections or the flesh bones (pin bones).By reason of their rearwardly inclined position and/or the chamfer 90 at their lower side 89, each circular knife 81 and 82 is deflected on engaging the rear edge 92 of the collar bone 91 (supraclavicula) and the os posttemporale forming one lateral skull bone and is displaced upwardly so that the cut extends over the os occipitale closing the skull off upwardly. The bone skeleton carrying the head can while maintaining the saddling-up be conducted to further tools which for example make the detaching of the belly lobes possible by cutting or scraping or permit the obtaining of the collar bones with the flesh adhering to them. To make the displacement of the rib cutting knives 81 and 82 more certain, these can be actuated by an active control shortly before the start of the deflecting motion in the sense of a weight compensation.

An advantage of the embodiment described above byway of example is that beheading of even small fish or severing of their collar bones is not necessary before filleting so that the cost incurred with a beheading machine and its operation can be saved.

Claims (10)

1. Amethodoffilleting unbeheadedfish,comprising the steps of performing belly filleting cuts, back filleting cuts and rib cuts on a fish while the fish is being advanced tail forward, the fillets being severed from the remainder of the fish after performing the rib cuts by so cutting the fish adjacent the collar bone and in a direction inclined towards the roof of the skull that at least one of the collar bone and the head remain on the fish.

2. A method as claimed in claim 1, wherein each rib cut comprises an arcuate cut starting at the end of the abdominal cayity and a straight cut extending above the ribs or the vertebral projections and continuing into the severing cut.

3. A method as claimed in either claim 1 or claim 2, wherein each rib cut extends from the belly flap aboe the flesh bones up to and beyond the collar bone as the severing cut.

4. A process as claimed in any one of the preceding claims, wherein the rib cuts enclose an angle of less than 1800 towards the belly side of the fish while ieaving the belly flaps on the bone skeleton.

5. A method for filleting unbeheaded fish, substantially as hereinbefore described with reference to the accompanying drawing.

6. An apparatus for filleting unbeheaded fish, comprising conveyor means to convey the fish, a pair of belly filleting knives, a pair of back filleting knives, a pair of rotatable rib cutting knives, and control means for the rib cutting knives, the axes of rotation of the rib cutting knives being almost parallel to each other and inclined in the conveying direction, each rib cutting knife being displaceable in a direction parallel to its axis of rotation and the control means being operable to displace the rib cutting knives in the direction of the dorsal side of the fish at least on the arrival of the abdominal cavity thereof.

7. An apparatus as claimed in claim 6, wherein each rib cutting knife is provided with a chamfer at the side thereof which in use faces the belly side of the fish.

8. An apparatus as claimed in either claim 6 or claim 7, comprising support means disposed upstream of the rib cutting knives.

9. An apparatus as claimed in any one of claims 6 to 8, the conveyor means comprising a plurality of saddle members each arranged to convey a respective fish and to actuate the control means.

10. An apparatusforfilleting unbeheadedfish, substantially as hereinbefore described with reference to Figure 1 and Figure 2 of the accompanying drawings.