GB2032246A - Skinning fish fillets - Google Patents

Abstract

An apparatus for skinning fish fillets comprises a rotatable skinning roller (2), conveyor means (1) for advancing the fillet to the skinning roller (2), a rotatable transfer roller (3) disposed between the conveyor means (1) and the skinning roller (2), and a skinning knife (4) provided with a cutting edge (41) and a presser face (42) each equi-spaced from the periphery of the skinning roller (2). The periphery of the skinning roller (2) is provided with lands (22) for transporting the fillet and supporting it at the skin side thereof and grooves (25) separating the lands (22). <IMAGE>

Description

SPECIFICATION Apparatus for the skinning of fish fillets The present invention relates to an apparatus for skinning a fish fillet.

Known apparatus for skinning a fish fillet comprises skinning rollers which are provided on their periphery with uniform arrangement of teeth in which the teeth are very narrow and the gaps between the teeth relatively large and deep. To improve the running-in of the skin of the preceding fish fillet end under the cutting edge of the skinning knife the skinning knife is provided, at its cutting edge, with a surface directed away from and against the rotational direction of the periphery of the skinning roller.

Such apparatus has a number of advantages. They have a simple construction, the drive for an oscillating skinning knife can be dispensed with and they make the removal of the skin possible without loss of a tip of flesh at the preceding end of the fish fillet.

However, they also have disadvantages. The yield of fish flesh attainable with such apparatus is not satisfactory because the largest part of the gain in fish flesh attained by the non-loss of the flesh tip at the preceding end of the fish fillet gets lost due to the fact that a thicker layer of fish protein remains on the entire skin surface than is the case with skinning apparatus with a switchable skinning knife.This not only reduces the yield in fish flesh, but also impairs the appearance and the consistency of the skinned fish fillets, because maintenance of the silver layer with the protective layer lying thereunder on the skin side of the fish fillet is only attainable with difficulty or is even not obtainable at all. Afurther important defect of such apparatus is that fillets of fish with thick and/or scaly skin cannot be skinned at all or at least not reliably, while the running-in ofthe skin below the cutting edge of the skinning knife is not properly attained even with a skinning knife provided with a surface directed against the circulating direction of the skinning roller.

According to the present invention there is provided an apparatus for skinning fish fillets, comprising a rotatable skinning roller, conveyor means for advancing the fillet to the skinning roller, a rotatable transfer roller disposed between the conveyor means and the skinning roller, and a skinning knife provided with a cutting edge and a presser face each equi-spaced from the periphery of the skinning roller, the periphery of the skinning roller being provided with lands for transporting the fillet and supporting it at the skin side thereof and groove means separating the lands.

The conveyor means may comprise an endless belt.

The grooves may extend axially ofthe skinning roller. Thereby, the skinning roller is easily manufacturable.

The groove means may extend helically around the skinning roller. This enables, in the case of narrow grooves, the engagement length forthe skin to be enlarged.

The groove means may comprise helical grooves which cross one another. Thereby, the number of the engagement locations of the skin may be increased.

The groove means be arranged in arrow shape.

Thereby, the flash resting of the skin may be improved by being outwardly stretched.

The groove means may be so arranged thatfor any angular position of the skinning roller at least part of the groove means is disposed opposite the presser face.

The groove means may have a base which is narrower than the mouth and may have opposite side walls which taper towards each other from the mouth, the depth of the groove means preferably being less than the least width thereof. Thereby, the space for the running-in of the skin lets itself be dimensioned adequately without side effects on the silver mirror taking place.

The lands of the skinning roller may be rough and the roughness may be produced mechanically, che mically or electrolytically. The roughness provides a co-efficient of friction adequate for the entrainment of the skin without endangering the yield of fish flesh.

The lands of the skinning roller may be provided with a fine toothing. Thereby, the skin of fish fillets with large skinning resistance can be conveyed securely.

The tranfer roller may be provided with a fine toothing. Thereby, further quietening of the preceding end of the fish fillet before its running-in into the skinning knife is attainable.

A presser roller may be disposed in proximity of the cutting edge of the skinning knife. Thereby, automatic checking or alignment of the preceding end of the fish fillet and consequentlythe secure running-in thereof may be attained.

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 an apparatus embodying the present invention.

A deflecting roller 11, a transfer roller 3 and a skinning roller 2 are journalled in a frame (not shown) and driven counter-clockwise as shown by the arrows on the periphery of the rollers. An endless feed belt 1 is looped around the deflecting roller 11 and tensioned by a roller (not shown). The transfer roller 3 and the skinning roller 2 each run at a higher peripheral speed than the feed belt 1. A skinning knife 4 is arranged fast with the frame above the upper half of the skinning roller 2 and has a presser face 42 equidistantly from the peripheral surface 21 of the skinning roller 2. The gap between the cutting edge 41 or the presser face 42 and the peripheral surface 21 of the skinning roller 2 is a few tenths of a millimetre.Advantageously, the skinning knife 4 is so arranged that it can deviate away from the periphery of the skinning roller 2 against strong spring pressure. Arranged above the cutting edge 41 of the skinning knife 4 is an integral or multi-part presser roller 5, which is driven in the direction shown by the arrow on the periphery of the presser roller and which is arranged to be deviatable against a spring force.

The cylindrical peripheral surface 21 ofthe skinning roller 2 is divided by axial grooves 25 into lands 22 which possess roughenings of small radial depth.

The rough surface may be provided by for example crossed knurls 23 or fine toothing 24 which serve to entrain the skin along the presser face 42 of the skinning knife 4. The grooves 25 have the shape of non-uniform trapeziums, the depth 27 of which amounts to only a fraction of their width 26. The width of the grooves may be about 5 millimetres and their depth about 1.5 millimetres. The surface of the transfer roller 3 is provided with a fine toothing and also the surface of the presser roller 5 is advantageously provided with a profiling not shown of small depth.

The apparatus operates as follows: Afish fillet laid with its skin side on the feed belt 1 is fed by the feed belt 1 with its tail end forward to the deflecting location above the deflecting roller 11, where the transfer roller 3 guides the tail tip onto the peripheral surface 21 of the skinning roller 2. The fine toothing 31 of the transfer roller 3 is in a position to raise the fillet end from the feed belt 1 but prevents excitation of the fish fillet end into a vertical flapping motion. The skinning roller 2 rotates more rapidly than the fed tail end of the fish fillet and rotates with its lands 22 and grooves 25 below the skin side of the fish fillet until the preceding end thereof has reached the cutting edge 41 of the skinning knife 4. The roughness of the lands 22 of the skinning roller 2 cause the skin to rest flush on the peripheral surface 21.In consequence thereof, the skin of the tail end drops briefly into the grooves 25 respectively passing through below it. When the tail end of the fish fillet again penetrates with its skin into a groove 25 on reaching the cutting edge 41 of the skinning knife 4 wedging of the skin takes place instantaneously through the presser face 42 lying below the cutting edge 41 and enables the cutting edge 41 to penetrate between the skin and silver layer of the fish fillet and thereby to sever the fish fillet from the skin. This process is performed with great certainty when the fish fillet is conveyed forward spread out from the feed belt 1. The presser roller 5 disposed above the cutting edge 41 comes into effect particularly when irregularities are present in the position of the fish fillet.

Advantages of the embodiment described above by way of example are that the skin is uniformly supported over the lands, the yield in fish flesh is increased due to a uniform silver mirror being attainable on the fish fillet and the end of the fillet in front of the skinning knife experiences no longitudinal compression. Also the running-in of the skin of the preceding fish fillet end takes place securely and without delay with every kind of fish because it does not execute a vertically dancing motion which is caused by the teeth of the skinning roller of known apparatus, but lies flush on the lands of the skinning roller rotating under it. The skin of the preceding end of the fish fillet is also able to penetrate into one of the grooves and come below the cutting edge of the skinning knife.

Claims (16)

1. An apparatus for skinning fish fillets, comprising a rotatable skinning roller, conveyor means for advancing the fillet to the skinning roller, a rotatable transfer roller disposed between the conveyor means and the skinning roller, and a skinning knife provided with a cutting edge and a presser face each equi-spaed from the periphery of the skinning roller, the periphery of the skinning roller being provided with lands for transporting the fillet and supporting it at the skin side thereof and groove means separating the lands.

2. An apparatus as claimed in claim 1,wherein the convey means comprises an endless belt.

3. An apparatus as claimed in either claim 1 or claim 2, the groove means extending axially of the skinning roller.

4. An apparatus as claimed in either claim 1 or claim 2, the groove means extending helically around the skinning roller.

5. An apparatus as claimed in claim 4, the groove means comprising helical grooves which cross one another.

6. An apparatus as claimed in either claim 1 or claim 2, the groove means being arrow shaped.

7. An apparatus as claimed in any one of the preceding claims, the groove means being so arranged that for any angular position of the skinning roller at least part of the groove means is disposed opposite the presser face.

8. An apparatus as claimed in any one of the preceding claims, the groove means having a base which is narrower than the mouth and having opposite side walls which taper towards each other from the mouth, the depth of the groove means being less than the least width thereof.

9. An apparatus as claimed in any one of the preceding claims, wherein the lands of the skinning roller are rough.

10. An apparatus as claimed in claim 9, wherein the rough lands have been produced mechanicaily.

11. An apparatus as claimed in claim 9, wherein the rough lands have been produced electrolytically.

12. An apparatus as claimed in claim 9, wherein the rough lands have been produced chemically.

13. An apparatus as claimed in any one of claims 1 to 8, wherein the lands of the skinning rollers are provided with a fine toothing.

14. An apparatus as claimed in any one of the preceding claims, wherein the transfer roller is provided with a fine toothing.

15. An apparatus as claimed in any one of the preceding claims, comprising a presser roller disposed in proximity of the cutting edge of the skinning knife.

16. An apparatus for skinning a fish fillet, substantially as hereinbefore described with reference to the accompanying drawing.