GB2046578A - Filleting fish - Google Patents

Abstract

A fish filleting machine (and corresponding method) comprises a conveyor for transporting the fish tail forwards, a respective pair of belly filleting knives (3), back filleting knives (4), rib knives (5), first severing knives (6) for the severing through of the flesh strip and second severing knives (7) for the severing of the fillets at the tail root of the fish. A closed guide track (2) for the backbone of the fish is arranged between the belly filleting knives (3) or the back filleting knives (4) and the second severing knives (7) for the severing of the fillets at the tail root. The first severing knives (6) for the severing through of the flesh strip lie between the belly filleting knives (3) or the back filleting knives (4) and the rib knives (5) and are connected with control means (8), which are actuated synchronously wish the conveyor (1) and bring the first severing knives (6) into a setting crossing the guide track (2) before arrival of the abdominal cavity end of the respective fish. <IMAGE>

Description

SPECIFICATION Filleting of fish The present invention relates to the filleting of fish.

In known processes for filleting fish, rib cuts start at the abdominal cavity end at the side of the tail and leave a trough-like depression at this point in every fillet. The piece of flesh cut out of the fillet remains on the bone skeleton and represents a measurable loss of flesh yield. The trough-like depression comes into being through the parts of the fish connected with the back-bone through a respective tape of flesh, which remains uncut laterally beside the vertebrae of the back-bone between belly filleting knives, and back-filleting knives, disposed closely behind the end of the abdominal cavity, do not let themselves be raised exactly into the planes of the rib knives. DE-PS 943612 discloses a fish filleting machine comprising a severing apparatus arranged behind the rib knives severing through these flesh tapes.Redisposition of the severing apparatus in front of the rib knives was however not possible in this filleting machine, because the back bone was not deviatably guided at least from above in the region between the back filleting knives and the rib knives.

According to one aspect of the present invention there is provided a method of filleting fish, comprising the steps of conveying the fish tail forwards and cutting fillets from the fish by performing a pair of belly filleting cuts, a pair of back filleting cuts, a pair of rib cuts and severing the fillets from the bone skeleton of the fish by means of severing cuts, the fillets, after the performance of the belly filleting cuts and the back filleting cuts, being detached in the region of the abdominal cavity end by severing through a flesh strip connecting the fillets with the vertebrae, and being cut free from lateral vertebral projections and ribs in the region of the abdominal cavity by means of the rib cuts and thereafter completely severed from the bone skeleton by severing through the flesh strip from the tail root to behind the abdominal cavity.

The advantages attainable by this method are that the fillets are no longer obstructed against deformation in the region of the abdominal cavity end of the fish; the rib knives can therefore produce a smooth cut and a greater flesh is attainable as result.

According to another aspect of the present invention there is provided a filleting machine comprising conveyor means to convey fish tail forwards, a pair of belly filleting knives, a pair of back filleting knives, a pair of rib cutting knives, a first pair of severing knives for severing through flesh of the fish, a second pair of severing knives for severing the fish at the tail root thereof, guide means for guiding the backbone of the fish and disposed between the second severing knives and at least one of the pair of filleting knives and the pair of back filleting knives, the first severing knives being disposed between the pair of rib knives and at least one of the pair of belly filleting knives and the pair of back filleting knives and being connected with control means actuable synchronously with the conveyor means to dispose the first severing knives at a position at which they traverse the guide means before arrival of the abdominal cavity end of the fish.

With such a filleting machine it is possible to let the rib cuts extend smoothly and without depression in prolongation of the belly filleting cuts and thereby to attain an increased yield in fish flesh.

The first severing knives may be displaceable against a spring force in the conveying direction of the fish. This enables the flesh band to be severed through up to the last vertebral projections at the abdominal cavity end.

The conveyor means may be provided with spaced entraining elements each adapted to engage a respective fish. This enables control of the first severing knives to be facilitated and such control to be simple.

The rib knives may comprise shaving tools. This enables the rib cuts to be performed smoothly and flesh to be saved especially when the fillets connected with the fish skeleton at the tail root are held in a stretched condition.

An embodiment of the present invention will now be more particularly described by way of example and with reference to the accompanying drawing, the single figure of which shows an axonometric illustration of part of a fish filleting machine embodying the present invention.

Referring to the accompanying drawing, deflecting wheels of an endless conveyor 1 are journalled in a frame (not shown) and are drivable in the direction of the arrow. The conveyor 1 carries thrust saddles 9 on which fish saddled by their abdominal cavities can be transported at fixed spacings. The thrust saddles 9 are advanced by the conveyor 1 in a guide track 2 which comprises two upper and two lower bone guides (not shown) and serves for the passage of the vertebral column of the fish. Underneath the guide track 2, a pair of belly filleting knives 3 are arranged at its upstream end and a pair of rib knives 5 at its downstream end.Above the guide track 2, a pair of back filleting knives 4 are arranged in the proximity of the belly filleting knives 3 and a pair of severing knives 7 at the downstream end of the guide track 2 for the severing of the fillets from the bone skeleton in their tail region. A pair of severing knives 6 which are like a planing tool and which are raisable and lowerable for severing through the flesh strips are arranged above the guide track 2 between the back filleting knives 4 and rib knives 5 and connected with control means 8 so as to be driven synchronously with the conveyor.

The method of operation of the filleting machine is as follows: A fish, opened at least in its abdominal cavity and degutted, is so saddled by its abdominal cavity on one of the thrust saddles 9 that its tail points in the direction of motion of the conveyor 1. When the fish is fed by guide means (not shown) to the belly fillet ing knives 3, these produce two incisions extending from the abdominal cavity end up to the end of the abdominal cavity, to both sides of the belly spokes of the bone structure. At the same time, the back filleting knives 4 also produce incisions, extending from the tail root up to the neck, to both sides of the back spokes. Before the abdominal cavity end of the fish reaches the severing knives 6, the knives 6 are moved downwardly and cross the path of motion 2 of the fish.They penetrate by their points both the flesh bands connecting the fillets with the spinal col umnandseverthesethrough uptotheendofthe abdominal cavity. After reaching the abdominal cavity, they are deflected upwardly by the lateral vertebral projections and prolong the incisions made in the fish by the back filleting knives 4, downwardly to the upper side of the lateral vertebral projections. On reaching the rib knives 5, spreaders or cutting supports, disposed before the cutting edges of the rib knives, steer both the fillets upwardly in the region of the abdominal cavity end and the rib knives 5 sever the fillets off from the lateral vertebral projections and ribs without their cutting edges penetrating into the fillets and producing a depression eachtime. On reaching the severing knives 7, the fillets are severed at their tail root and to both sides of the back bone.

The above described embodiment of the present invention enables fillets to be produced with a greater flesh yield and smoother appearance than hitherto.

Claims (7)

1. A method of filleting fish, comprising the steps of conveying the fish tail forwards and cutting fillets from the fish by performing a pair of belly filleting cuts, a pair of back filleting cuts, a pair of rib cuts and severing the fillets from the bone skeleton of the fish by means of severing cuts, the fillets, after the performance of the belly filleting cuts and back filleting cuts, being detached in the region of the abdominal cavity end by severing through a flesh strip connecting the fillets with the vertebrae, and being cut free from lateral vertebral projections and ribs in the region of the abdominal cavity by means of the rib cuts and thereafter completely severed from the bone skeleton by severing through the flesh strip from the tail root to behind the abdominal cavity.

2. A method of filleting fish, substantially as hereinbefore described with reference to the accompanying drawing.

3. Afilleting machine for performing the process as claimed in either claim 1 or claim 2, comprising conveyor means to convey fish tail forwards, a pair of bellyfilleting knives, a pair of backfilleting knives, a pair of rib cutting knives, a first pair of severing knives for severing through flesh of the fish, a sec ond pair of severing knives for severing the fish at the tail root thereof, guide means for guiding the backbone of the fish and disposed between the sec ond severing knives and at least one of the pair of filleting knives and the pair of back filleting knives, the first severing knives being disposed between the pair of rib knives and at least one of the pair of belly filleting knives and the pair of back filleting knives and being connected with control means actuable synchronously with the conveyor means to dispose the first severing knives at a position at which they traverse the guide means before arrival of the abdominal cavity end of the fish.

4. Afilleting machine as claimed in claim 3 wherein the first severing knives are displaceable against a spring force in the conveying direction of the fish.

5. A filleting machine as claimed in either claim 3 or 4, wherein the conveyor means is provided with spaced entraining elements each adapted to engage and convey a respective fish.

6. A filleting machine as claimed in any one of claims 3 to 5, wherein the rib knives comprise shaving tools.

7. A filleting machine substantially as hereinbefore described with reference to the accompanying drawing.