Patent Description:
Some fish have only one pelvic fin, other fish such as some Tilapia have two pelvic fins on opposite sides of a centre plane. The two pelvic fins are typically connected by a tough bone or cartilage structure. When filleting fish in a filleting machine, the quality of the filleting process can be disturbed by the pelvic fins of the fish and particularly by the tough structure connecting right and left side pelvic fins. This is especially the case if the pelvic fins or the connection between them are very hard. Tilapia fish and other fish from the family Cichlidae are examples of such fish.

To avoid disturbance from the pelvic fins of fish to be filleted in a filleting machine, one opportunity is to cut off the pelvic fins. Cutting away the pelvic fins is often performed manually increasing the cost and complexity of the filleting process.

<CIT> discloses an apparatus for removing bones from flesh in a fish body in which a blade assembly is movable relative to a jig which holds the fish.

It is an object of embodiments of the invention to enable a more precise filleting and reduced manual intervention in the filleting process. It is a further object to reduce machine complexity and potentially increase processing speed.

According to these and further objects, the invention, in a first aspect, provides a fish filleting machine as defined in claim <NUM> for cutting fillets from fish. The machine comprises a feed-line for feeding fish through the machine in an upright orientation with right and left sides of the fish on opposite sides of a centre plane.

The machine further comprises a cutting device for filleting at least the ventral part of the fish.

Upstream of the cutting device, the machine comprises a pelvic fin splitter arranged to split a connection between the right side pelvic fin and the left side pelvic fin of the fish.

By splitting a connection between the right side pelvic fin and the left side pelvic fin of the fish is to be understood the process of splitting a structure connecting two pelvic fins located on each half part of the fish, i.e. on opposite sides of the centre plane. This connection is disconnected by a cut through the connection e.g. without removing the pelvic fins.

Surprisingly, it has been observed that splitting and thus separating the pelvic fins from each other results in a good filleting process and prevents a typically occurring displacement occurring when filleting knifes reach the pelvic fins or the tough structure connecting the pelvic fins.

Furthermore, for a filleting machine with the pelvic fin splitter, the manpower required to perform manual removal of the pelvic fin is lowered since the pelvic fins can stay on the fish during filleting.

The connection between the pelvic fins may particularly be split by a cut directed substantially parallel to the spine of the fish. For this purpose, the fin splitter may comprise a knife arranged to cut along the centre plane. The centre plane, herein, means a virtual plane vertically through the fish and defining a plane of symmetry through the fish with a right side of the fish on the right side of the centre plane and a left side of the fish on a left side of the centre plane.

The fish to be filleted is preferably de-headed and gutted before fed to the infeed of the filleting machine. The de-headed fish can be fed head part first or tail part first, where 'first' illustrates the fish part first reaching the cutting section of a filleting machine. By head part is meant the end of the fish where the head has been removed. Also, the de-headed fish may be fed with the dorsal side up in the infeed or with the ventral side up. Preferred is when the fish is fed in the infeed with head part first. More preferred is when the fish is fed with the de-headed head part first and the ventral side up. The filleting machine and method described herein is illustrated with fish fed head part first and the ventral side up.

The term "centre plane", when used herein refers to a virtual vertical plane separating the two pelvic fins and indicating a preferred location for the pelvic fin splitter to split the connection between the two pelvic fins.

The fish may be carried through the machine with the left and right sides of the fish on opposite sides of a splitting plane defined by the pelvic fin splitter.

The fish may be held in the position where the pelvic fin splitter splits the connection between the two pelvic fins by transport bands and pressing means which are disclosed relative to the drawings.

The pelvic fin splitter may comprise at least one cutting edge for splitting the connection between the pelvic fins, and separating the pelvic fins from each other. The cutting edge may be of any form e.g. a straight knife capable of cutting between the pelvic fins. As described the connection between the two pelvic fins may be tough and breaking this connection e.g. by cutting has the advantage of reducing the risk of disturbances in the cutting process when cutting along the ventral part of the fish to separate part of the fish from the vertebral column.

In a preferred embodiment the pelvic fin splitter comprises at least one circular cutting blade with an outer cutting edge, such as two circular cutting blades or more preferred a single circular cutting blade with an outer cutting edge.

The cutting device for filleting at least the ventral part of the fish may comprise a set of two band saws, where one band saw cuts the right side of the fish and the other band saw cuts the left side of the fish i.e. each band saw cuts both the ventral and the dorsal part of the fish fillets at the side where that band saw is located. In another embodiment, the cutting device may comprise a set of two circular, rotating cutting blades arranged on opposite sides of the centre plane.

The cutting device for filleting at least the ventral part of the fish may also comprise a first set of cutting blades for cutting the dorsal or the ventral part of the fish by cutting towards and along the vertebral column, and a second set of cutting blades for cutting that dorsal or ventral part of the fish which was not cut by the first set of cutting blades, particularly by cutting towards and along the vertebral column.

The pelvic fin splitter preferably defines a splitting plane located between cutting planes defined by the cutting device for filleting at least the ventral part of the fish such as between cutting planes of the first or second set of cutting blades for cutting the ventral part of the fish.

The splitting plane of the pelvic fin splitter and the cutting planes of the first or second set of cutting blades may be substantially parallel to the feed-line.

A location of the splitting plane of the pelvic fin splitter substantially with an equal distance to both pelvic fins, i.e. a location of the pelvic fin splitter with its plane in the centre plane of the fish, creates substantially two similar half parts of the pelvic fin connection. In the following filleting process, this may improve the cutting processes and equally affect the symmetry of the fillets. Accordingly, the pelvic fin splitter may be arranged to define a splitting plane essentially centrally between the two pelvic fins.

The cutting device for filleting the fish may, likewise, be arranged with its two cutting planes symmetrically on opposite sides of the centre plane and thus symmetrically relative to the splitting plane of the filleting machine to thereby cut the two sides of the vertebral column symmetrically.

The filleting machine may further comprise an actuator to which the pelvic fin splitter is connected. The actuator may be capable of locating and de-locating at least a part of the pelvic fin splitter such that the pelvic fin splitter has a cutting line located between the at least one set of cutting devices such as between the cutting lines of the first or second set of cutting blades for cutting the ventral part of the fish.

The actuator may further be capable of locating and de-locating at least a part of the pelvic fin splitter between the at least one set of cutting devices such as between a set of cutting blades of the first or second set of cutting blades for cutting the ventral part of the fish.

Upstream, herein, refers to a location of the pelvic fin splitter being before the cutting device in the feeding direction of the fish through the machine. The location of the pelvic fin splitter may particularly be close to the cutting device, e.g. with a cutting blade of the pelvic fin splitter partly overlapping the cutting blades of the cutting device in the feeding direction of the fish through the machine.

An advantage of having the pelvic fin splitter located just upstream of the cutting device such as just upstream of the first or second set of cutting blades for cutting the ventral part of the fish is that the fish may be held stably and fixed relative to the centre plane while performing both the pelvic splitting and the filleting. At this position of the pelvic fin splitter and the cutting device, the fish may be influenced by means capable of positioning the fish before performing the cutting process. the fish can be arranged in the correct position for all the cutting processes taking place, and no further positioning means may be required at other locations of the machine. the pelvic fin splitter may be included in a fish filleting machine without introducing additional positioning means. The positioning means may include e.g. spring-like elongated members biassing the fish from opposite sides of the centre plane towards the centre plane.

The filleting machine may further comprise a controller for controlling the actuator. The controller may control the actuator according to the location of a fish to be cut relative to the pelvic fin splitter. Hereby the pelvic fin splitter may be activated, and the cutting edge of the pelvic fin splitter can be located to cut through the connection between the pelvic fins of a fish transported along the feed-line and passing the pelvic fin splitter.

The controller may also control the actuator according to the location of a fish to be cut relative to the pelvic fin splitter, such that the pelvic fin splitter can be de-activated, and the cutting edge of the pelvic fin splitter is removed from cutting into a fish transported along the feed-line. In this situation the pelvic fin splitter may be activated at a time where no fish is passing the pelvic fin splitter, and hereby the pelvic fin splitter is in place when the next fish is moved towards the pelvic fin splitter.

The controller may also control the actuator to activate and de-activate the pelvic fin splitter such that the pelvic fin splitter is in position to split the connection between the pelvic fins of a fish just before the pelvic fin is to pass the location of the pelvic fin splitter, and such that the pelvic fin splitter is moved out of the cutting position as soon as the connection between the pelvic fins of a fish has been cut.

An advantage of a controller and actuator to locate and de-locate the pelvic fin splitter is that a cut can be made selectively, e.g. only in that part of the fish where it is required or scheduled to be made. Hereby, the pelvic fin splitter may not cut into fish meat that can be located on portions which can be sold. Such cutting into fish meat may lower the quality of the portion.

At least one sensor may be used to determine the location of the fish to be filleted and/or to determine the location of the pelvic fin of the fish to be filleted. The sensor(s) can send information to the controller which can control the vertical location of the pelvic fin splitter, hereby the pelvic fin splitter can be controlled such that only the connection between two pelvic fins is cut.

In the filleting machine the set of cutting blades of the first or second set of cutting blades for cutting the ventral part of a fish and the pelvic fin splitter is preferably located along and at least mainly above a horizontal line or plane of the feed-line for feeding fish through the filleting machine and the first or second set of cutting blades for cutting the dorsal part of a fish is located along and at least mainly below the horizontal line or plane of the feed-line. Preferably the first set of cutting blades and second set of cutting blades are displaced relative to each other along the horizontal line or plane, such that the two sets of cutting blades are not located directly above and below each other. The horizontal line or plane may be a thin line or plane and the first and second set of cutting blades may each touch the line or plane, one blade from above and one blade from below, or one of the blade may have a small part of the blade located on the other side of the line or plane. Hereby, a fish when being cut by the first and second set of cutting blades is performing an s-shaped travel through this cutting process.

In a second aspect, the invention provides a method as defined in claim <NUM> for filleting a fish from a species of a kind having a right side pelvic fin and a left side pelvic fin on opposite sides of a centre plane of the fish.

The method comprises a step of splitting a connection between the right side pelvic fin and the left side pelvic fin and subsequently filleting the fish by cutting right and left side fillets at least from the ventral part by cutting on opposite sides of the central plane of the fish.

The splitting may be carried out in a direction substantially parallel to the spine of the fish. e.g. along the central plane of the fish.

The method may be carried out without removing the right and left side pelvic fins from the fish, and the subsequent filleting may, likewise, be carried out without removing the right and left side pelvic fins from the right and left side fillets.

The pelvic fins may, eventually, be removed from the fillets after the filleting has occurred.

This could take place immediately after the filleting or later in time.

The splitting of the connection between the pelvic fins and the filleting takes place in a fish filleting machine according to the first aspect of the invention, and the method comprises the steps of.

Several fish may be in the feed-line at the same time, and the feed-line may direct the fish towards the pelvic fins splitter, one fish at a time.

The method may also comprise the steps of.

The methods described above may further comprise a step of directing the pelvic fin splitter away from the fish after the step of splitting the connection between the pelvic fins of the fish by the pelvic fin splitter.

In the method, a controller may be controlling the step of directing the pelvic fin splitter towards the pelvic fin of the fish and/or the step of directing the pelvic fin splitter away from the fish, such that the pelvic splitter cuts into the connection between the pelvic fins only.

More steps or details of the method is available in the description of the filleting machine above and in the description of the figures.

<FIG> illustrates part of a fish filleting machine <NUM> illustrating a feed-line for fish passing through the filleting machine <NUM>. The transport direction of fish to be filleted is indicated by the arrow <NUM>. In this embodiment the fish (not illustrated) is to be fed preferably de-headed, though the machine with the head part first, and with the dorsal part downward in the infeed <NUM>, see <FIG> for illustration of the fish in the filleting machine <NUM>. The infeed <NUM> is preferably longer than indicated in this figure. Downstream the infeed <NUM>, orientation means <NUM> are illustrated for securing proper orientation of a fish before a transport band <NUM> engages with the fish. The transport band <NUM> transports the fish pass different knives and towards an outlet <NUM>.

Illustrated are a pelvic fin splitter <NUM>, a first set of cutting blades <NUM>, a second set of cutting blades <NUM>, a third set of cutting blades <NUM> and a fourth set of cutting blades <NUM>, here being a set of two band saws, one located on each side of the feed-line. The cutting blades, <NUM>, <NUM>, <NUM> and <NUM> constitute the cutting device. The pelvic fin splitter is located upstream the cutting device in the direction of the transport of fish illustrated by the arrow <NUM>.

Downstream the first set of cutting blades <NUM> is a set of guides <NUM> for guiding the fillet parts cut by the first set of cutting blades <NUM> outside the fourth set of cutting blades <NUM> as this cuts fish meat located along the vertebral column of the fish.

<FIG> illustrates a closer look at the cutting section of the fish filleting machine <NUM>. An outline <NUM> of a de-headed fish <NUM> with the tail <NUM>, the pelvic fins <NUM> and the dorsal fin <NUM> illustrates the location of the fish just prior to the filleting process. The fish should be between the set of transport bands <NUM> during the filleting process, but for illustration the outline <NUM> of the fish is indicated on top of the feed-line. The fish <NUM> is illustrated with de-headed head part first and ventral side up in the feed-line. During the filleting process the pelvic fin <NUM> can be split by the pelvic fin splitter <NUM>, the ventral part of the fish <NUM> can be filleted by the first set of cutting blades <NUM>, the dorsal part of the fish <NUM> can be filleted by the second set of the cutting blades <NUM>, a part of the fish meat along the vertebral column at the dorsal part of the fish <NUM> can be cut by the third set of cutting blades <NUM>, and the part of the fish meat located at the sides of the vertebral column can be cut by the fourth set of cutting blades <NUM>. The set of guides <NUM> will guide the part of the fillet cut free by the first set of cutting blades <NUM>, such that this cut free part of the fillet is not cut by the fourth set of cutting blades <NUM>. An actuator <NUM> connected to the pelvic fin splitter <NUM> may be controlled to position the pelvic fin splitter <NUM> to split the pelvic fin <NUM> only. Sensor(s) (not shown) may be used to determine the location of the fish <NUM> to be filleted and/or to determine the location of the pelvic fin <NUM> of the fish <NUM> to be filleted. The sensor(s) can send information to a controller (not shown) capable of controlling the vertical location of the pelvic fin splitter <NUM> as indicated by the double arrow <NUM> showing the pelvic fin splitter <NUM> can be moved up and down, and this can be done such that only the connection between two pelvic fins is cut.

<FIG> illustrates a perspective view from above the cutting knives with the blade of the pelvic fin splitter <NUM> partly located between two blades of a first set of cutting blades <NUM>. Some features are similar to what is described related to <FIG>. Clearly illustrated are the two transport bands <NUM> for transporting fish (not shown) through the cutting area. Different sets of orientation means or position means <NUM> are illustrated upstream of the first set of cutting blades <NUM>. Different sets of pressing means <NUM> are illustrated along the transport band <NUM>. The pressing means <NUM> are used to press on the lateral sides of the fish to be filleting hereby pressing the fish towards the cutting blades making it possible to keep the fish in correct positions and to cut the fillets as decided.

<FIG> illustrates the cutting knives seen directly from above with two sets of circular cutting blades <NUM>, <NUM> and a pelvic fin splitter <NUM> located partly between the cutting blades of the first set of cutting blades <NUM>.

Claim 1:
A fish filleting machine (<NUM>) for cutting fillets from fish, the machine comprising
• a feed-line for feeding fish in a feeding direction (<NUM>) through the machine and with right side and left side of the fish on opposite sides of a centre plane, the feed-line comprising:
• a cutting device (<NUM>, <NUM>, <NUM>, <NUM>) for filleting at least the ventral part of the fish characterized by further comprising:
• a pelvic fin splitter (<NUM>) located upstream of the cutting device (<NUM>, <NUM>, <NUM>, <NUM>) and configured for splitting a connection between a right side pelvic fin (<NUM>) and a left side pelvic fin (<NUM>) of the fish.