WO1996016552A1

WO1996016552A1 - Equipment for killing of fish such as salmon comprising gill cutting means

Info

Publication number: WO1996016552A1
Application number: PCT/NO1995/000216
Authority: WO
Inventors: Ole Molaug; Harald Arvid Kvalheim
Original assignee: Norsk Hydro A.S
Priority date: 1994-11-30
Filing date: 1995-11-22
Publication date: 1996-06-06
Also published as: NO944609D0; NO944609L

Abstract

An equipment for killing and cutting gills of fish, in particular farmed fish as salmon, comprising an extracted body (1) adapted to be entered into the mouth cavity of the fish. The body supports a built-in striking hook (2) and a built-in grill cutting knife or knives (6), each being adapted to be moved from a retracted position in the body to an extracted position outside the body and vice versa. The striking hook (2) and the knife/knives may be driven by hydraulic or pneumatic means through a common piston rod (3) connected with a piston (4).

Description

Equipment for killing of fish such as salmon comprising gill cutting means

The present invention relates to an equipment for killing of fish comprising gill cutting means, in particular fish such as salmon raised in a fish farm.

The operating procedure when killing salmon commonly involves the following steps:

Landing, killing/gill cutting, blood draining, and gutting/washing. When killing salmon and some other fish species, it is important to perform the killing in such a manner that the fish do not enter a state of stress, and that the blood is drained off rapidly, to obtain a good quality of the killed fish.

Commonly, farmed fish is anaesthetised in the water using CO₂, and the gill cutting operation is performed by cutting the gill bones manually with a knife.

According to the present invention, it is provided an equipment for killing farmed fish comprising gill cutting means that rapidly and in an "ethical" and effective manner performs the operation such that this will not stress the fish, whereby the quality of the fish meat is substantially improved.

The equipment according to the invention is characterised in that an extended body is adapted to be entered into the mouth cavity of the fish, as the body of the equipment supports a striking hook and a gill cutting knife or gill cutting knives, where said elements are adapted to be moved from a retracted position in the body to an extracted position outside the body and vice versa.

The dependent claims 2-6 describe advantageous features of the invention The invention is further described in the following by an embodiment thereof and with reference to the drawings, where:

Fig. 1 shows the equipment with the striking hook in a retracted position as shown by fully drawn lines, and in an extracted position as shown by dotted lines.

Fig. 2 shows the equipment as shown in fig. 1 , where it is turned 90° as to the position shown in fig. 1 , and where the gill cutting knives are shown in a retracted position by fully drawn lines, and in an extracted position by dotted lines.

Fig. 3 and 4 show the equipment in the same order as in fig. 1 and 2, entered into the mouth cavity of the fish and as both the striking hook and the gill cutting knives are shown in a retracted position by fully drawn lines, and in an extracted position by dotted lines.

As shown in the figures, the equipment according to the invention comprises an extended body with a frontal wedge-shaped section 13, that advantageously may be provided with a narrow projecting nose 14. Having this shape, the equipment may easily be entered into the mouth cavity of a fish.

Forming parts of the wedge-shaped section 13, both the nose 14 and a shoulder 15 arranged behind the nose have rounded edges that serves to avoid damage of the fish in the penetration operation.

The same provisions are made at the other parts of the wedge-shaped section 13 and the main body that advantageously may have a circular or oval shape. The equipment as shown in Fig 1 and Fig 2 is provided with a striking hook 2 and gill cutting knives 6 that all are supported in a built-in manner in the body 1 , where said elements are adapted to be moved out of a retracted position as shown by fully drawn lines, to an extracted position, as indicated by dotted lines, and vice versa

The striking hook 2 and the gill cutting knives 6 are all driven by a piston 4 through a piston rod 3 arranged at a central position in the body 1 The striking hook 2 has a hinged connection (at 17) with the piston rod 3, and is guided in recesses 10 provided in the body 1 (not further shown) by means of rollers 16 arranged at each side of the striking hook, as indicated in Fig 1 The gill cutting knives (in this embodiment there are two knives), have their frontal ends rotably connected with the body (at 18), as their other ends are connected with the piston rod 3 through a link arm, as indicated in Fig 2

The piston 4 may be driven by hydraulic or pneumatic means as pressurised fluid is supplied through one of the pressure lines 11 corresponding with one of the bores 5 depending on the direction of piston movement The pressurised fluid may be controlled by means of a two-way valve connected to the pressure lines 11 (not further shown)

Fig 3 and 4 shows the same equipment 1 in the same cut and at the same angle as shown in Fig 1 and 2 respectively while the equipment is entered into the mouth cavity 8 of the fish 7 The dotted illustration in Fig 3 shows the striking hook 2 in an extracted position where it has penetrated the cerebral matter of the fish Fig 4 shows the gill cutting knives 6 in an extracted position as the gills 12 of the fish have been cut off

In this phase of movement, as the striking hook and the gill cutting knives moves from a retracted position to an extracted position, the fish is put to death This killing is effectuated so rapidly that the fish will have no time to enter a state of stress that causes a quality reduction of the fish meat In the previous description it is shown and described a solution where the gill cutting knives and the striking hook are driven by a hydraulic or a pneumatic piston device. The invention, as defined in the claims, is not limited to comprise this solution. Thus, the striking hook and the gill cutting knives may, instead of being driven by hydraulic or pneumatic means, be driven by an electric motor, or it may be driven mechanically by a spring device.

The equipment as shown and described, may be operated manually or it may form part of an automatically operated killing- and gill cutting line for farmed fish.

Claims

Equipment for killing and cutting gills of fish, in particular farmed fish such as salmon, characterised in that an extended body (1) is adapted to be entered into the mouth cavity of the fish, where said body supports, in a built-in manner, a striking hook (2) and a gill cutting knife or knives (6), each being adapted to be moved from an retracted position in the body to a an extracted position at the outside of the body and vice versa

Equipment according to claim 1, characterised in that the stnkmg hook (2) and the knife/knives are driven by hydraulic or pneumatic means, through a common piston rod (3) connected with a piston (4)

Equipment according to claim 2, characterised in that the striking hook (2) has a hinged connection with the piston rod (3) and is further guided in recesses (10) provided in the body (1) through rollers arranged at each side of the striking hook

Equipment according to claim 2, ch a racte ri se d in that it compπses two knives (6) that are rotably supported at one end (at 18) in the body (1), and connected with the piston rod (3) through a link arm (9) at the other end

Equipment according to claim 1-4, ch a ra cte ri s ed i n that the body (1) is wedge-shaped at its frontal section (at 13)

Equipment according to claim 5, c h a ra ct e r i s e d i n that the frontal wedge-shaped section (13) is provided with a projecting, narrow nose (14)