WO2002035938A1

WO2002035938A1 - Method and apparatus for mechanically dividing flatfish into portion pieces

Info

Publication number: WO2002035938A1
Application number: PCT/NO2001/000409
Authority: WO
Inventors: Eivind Lygren
Original assignee: Puraq As
Priority date: 2000-10-09
Filing date: 2001-10-08
Publication date: 2002-05-10
Also published as: AU2001296092A1; NO312803B1; NO20005080D0; NO20005080L

Abstract

Flatfish is cut into predetermined portion pieces (c-h) of substantially equal weight by means of a cutting tool (12). The cutting tool (12) is an assemblage of a plurality of punching knifes (14a-14g) having a mutual configuration such that upon a working stroke of the punching tool fish within a given weight group is cut into said predetermined pieces.

Description

METHOD AND APPARATUS FOR MECHANICALLY DIVIDING FLATFISH

INTO PORTION PIECES

The invention relates to a method and apparatus for mechanically dividing flatfish into portion pieces.

An important aspect in order to expand the marketing potential of fresh fish beyond conventional sales, is to develop new types of products. Flatfish, such as turbot, has a low fillet yield owing to a high amount of large bones. Also, the quality of the flesh is rapidly reduced when filleted. Consequently it is rather unfit for conventional convenience food. Vacuum packing, combined with a rapid mechanical process for cutting the fish into pieces of equal weight would probably be an interesting project for promoting the commercial availability and obtaining a fair price of the fish, particularly with a view to the catering trade. Indeed, even experienced cooks find it difficult if not impossible to manually cut turbots into equal- ly sized pieces. Also, owing to the heavy bone structure, among other things, it is physically hard to sever the fish into servings.

Furthermore, when severing the fish for a particular market attention should be paid to local preferences and customs in the respective countries. What is preferred in Scandinavia is not necessarily appropriate in Spain or Italy. Irrespective of preferred cutting pattern it would be of great importance to have the flatfish pre- cut before it reaches the consumer.

Patent SE 353446 discloses a method and set of tools for dividing flatfish into almost equally sized portion bits by cutting the fish right through using a conventional endless saw blade intended for cutting meat. The division is based on the use of a plurality of unequal templates adapted to correspondingly unequal weight-groups of fish to be divided, associated with a size scale, whereby the fish is cut into portion bits in a multi-step operation.

Although this prior approach for mechanical or automatic cutting is an advance over the above discussed, manual process, it is still relatively demanding and expensive and therefore uneconomical in spite of the high price that would be obtainable for such pre-cut fish.

No patents 169 871 and 170 383 are further examples of prior art related to the mechanical dividing or severing of fish. However, this prior art is not intended for cutting the fish into portion or serving bits, nor is it apt to give a person skilled in the art any idea of how to improve the solution according to the above SE patent.

Thus, the primary object of the present invention is to provide a quicker and

5 more efficient and expedient approach for dividing flatfish than offered by the above prior art.

Also with pre-divided fish it would be important for the chef to be able to identify the various pieces or bits, since they are still of unequal quality, and the best pieces can then be reserved for preference customers. Therefore it is a o further object of the invention to provide a mechanical dividing technique avoiding through-cutting, permitting the fish to retain its natural shape in which the pieces are recognizable. This also adds to the attractiveness of the pieces when served. The customers may then choose for themselves and the fish will look better when brought to the table on a common dish. 5 According to the invention these objects are met by a method and apparatus as defined in the appending claims. '

When using this new technique the number of portion bits for each knife tool would be adapted to the different weight groups and the markets at which the fish is to be sold. Preferably the fish is not entirely intersected because, as noted o above, it would be highly beneficial to be able to keep the fish in its original shape, with head and tale intact, as it would permit the chef to recognize the pieces and serve the high quality pieces to preference customers. It would also permit serving the fish on a large dish in an aesthetically favourable manner and share out to the customers at the table. This is also advantageous with respect to presenting 5 and preparing/serving, when selling to ordinary consumers through super market or fish-mongers.

Summarizing, the invention offers the following advantages:

• The cutting process is finished in a few seconds.

• It is accurate and repeatable. o • The fish is not entirely intersected, rendering its original shape.

• The entire fish can be sold with head/tail etc avoiding weight losses relative to a price per kilogram to customer and causing improved presentation. • The cutting pattern is not bound by straight lines, also curved cutting lines may be used. This provides for a better utilization of the flesh of the fish.

The invention will be explained in more detail below, with references to the drawings in which: Figures 1 and 2 are side and elevation views, respectively, of a punching machine associated with the device according to the invention;

Figure 3 is a perspective view of a punching die;

Figure 4 is a top view of the punching die;

Figure 5 is an illustration of a turbot severed by use of the device according to the invention;

Figure 6 shows the contour of fishes within various weight groups positioned on a support plate; and

Figure 7 illustrates various severing patterns.

The punching machine itself, as schematically illustrated in figs. 1 and 2, is not part of the invention and may be of any design suitable for the particular punching process as discussed below. The essential aspect of the invention is the recognition of the technical and economical benefits of using a kind of punching process, such as by means of a punching machine as illustrated, for severing fish, and the specific punching die developed in this connection, as explained in more detail below.

In the example shown the punching machine comprises a substantially box- shaped bench 2 having a working top 4 supporting a rear upright bracket 5 with a cantilevered arm 6 protruding horizontally therefrom and carrying at the outer end thereof a vertically extending, preferably hydraulic power cylinder 7 having a piston rod 8 in turn carrying a punching die 12. Conveniently, the stroke of piston rod 8 is controlled by a foot pedal 10 in front of bench 2.

The partly schematic perspective view of fig. 3 illustrates a preferred embodiment of punching die 12 intended for severing or dividing a turbot into prede- termined portion pieces.

The punching die 12 of the exemplary embodiment shown in fig. 3 comprises a plurality of punching knives or blades 14a - g, preferably made from stainless steel, arranged in a pattern corresponding to the predetermined desir- able fish severance pattern. At their outer ends, the punching knives are attached to a circumferential knife retainer or frame 16, again preferably made from stainless steel, the geometrical shape of which substantially corresponds to the contour or outline of the fish to be severed. Frame 16 with knives 14 will normally be at- tached to a superjacent carrier plate 18 as shown in fig. 1 , which in its turn is adapted to be releasably connected, such as by fasteners (not shown), to a connecting flange 20, for example, at the lower (outer) end of piston rod 8.

As mentioned above, fig. 3 illustrates a preferred embodiment of the punching die according to the invention, reflecting an advantageous pattern for severing, e.g. turbot, into equally sized portion pieces, adapted to the shape and anatomy of the fish. As appearing from the figures, the punching die comprises a substantially longitudinal or central knife 14a for making a cut substantially along the spine of the fish, a rear (as referred to the fish) end cross knife 14b for making a cut behind the fish tail part, a front end cross knife 14c for making a cut behind the fish head part, and, at each side of central knife 14a, two additional cross knives 14d, 14e and 14f, 14g, respectively, adapted for severing the edible part of the body of the fish as desired. The spacing and configuration of the knives are such that the weight of the portion pieces defined by the knives in use is substantially the same, except for the head and tail portions beyond the rear 14b and front 14c cross knives, respectively, that are normally not contemplated as portion pieces and consequently not adapted to the remaining portion pieces as to weight. Preferably there is a set of punching dies 12, each die adapted to fish within a respective, predetermined weight group. An example of such groups is 0,9 - 1 ,1 kg, 1 ,4 - 1 ,6 kg and 1 ,7 - 1 ,9 kg. Fig. 6 depicts how fish within different weight groups are to be positioned on a positioning plate as explained below.

When using the device according to the invention as described above, the fish F to be processed is positioned on a support or positioning plate 22 slidably mounted between two positions on work bench top 4 as indicated with arrows in fig. 2, such as by intermediate tracks, rollers or other expedient sliding means 24. Initially the positioning plate 22 is in a first position sideways (at the left side in fig. 2) of the punch die, ready to receive fish to be processed. With the fish positioned on the plate, the latter is pushed, such as by hand, toward the right into a second position directly below the punch die. By means of the foot pedal 10 the punch piston rod 8 is caused to perform a punching stroke from an upper position as shown in figs. 1 and 2, to a lower position (not shown) in which the punching knives penetrate into the fish body, and back to the initial position. This causes the fish body to be severed in accordance with the punch die knife pattern, into head and tail portions a, b and six portion pieces c - h of substantially equal weight, as indicated in fig. 5.

The depth of penetration of the punching die into the fish can be adjusted as desired, such as by adjusting the stroke of the piston rod 8. Thus, the punching knives could be caused to penetrate completely through the fish, to leave the latter cut into separate or loose single pieces. Preferably, however, the punching operation is performed in a manner to prevent the punching knives from completely penetrating the fish body, to leave the various portion pieces in an interconnected relationship after punching. Advantageously, the punching stroke is adjusted such that when the punching knives 14 are in their bottom end position, a distance of about 3 - 5 mm remains between the lower edge of the knives and the support plate 22. The knives could have different depths, if desired, such that for example the central knife 14a, cutting along the spine of the fish, has a smaller depth than the remaining knives.

Figs. 7, I - VI, illustrates some examples of other possible punching pat- terns. The knives of the punching dies would then be correspondingly configured.

Claims

PATENT CLAIMS:

1. Method for mechanically dividing flatfish into predetermined portion pieces (a - h) of substantially equal weights, characterized by dividing the fish by means of a punching tool (12) having a plurality of punching knifes (14 a - g) configured in a manner such that upon a working stroke of the punching tool fish (F) within a given weight group is cut into said predetermined pieces (a - h).

2. Method according to claim 1, characterized by terminating the working stroke of the punching tool prior to full penetration of the punching knifes through the thickness of the body of the fish.

3. Method according to claim 2, characterized by terminating the working stroke when about 3-5 mm of the thickness of the fish body remains.

4. Apparatus for mechanically dividing flatfish into predetermined portion pieces of substantially equal weight, characterized by comprising a punching machine having a punching tool (12) assembly consisting of a plurality of punching knifes (14a - g) having a mutual configuration such that upon a working stroke of the punching tool fish within a given weight group is cut into said predetermined pieces.

5. Apparatus according to claim 4, characterized in that the working stroke of the punching tool (12) is sized such that the punching knifes (14a - g) do not completely penetrate the fish.

6. Apparatus according to claim 5, characterized in that the edge of the punching knifes (14a - g) at the end position of the working stroke is spaced about 3-5 mm above the top surface of a support plate (22) for the fish (F).

7. Apparatus according to claim 4 or 5, characterized in that it comprises a plurality of replaceable punching tools (12) each adapted to a respective fish weight group.