Note: Descriptions are shown in the official language in which they were submitted.
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BAC KGRO~N D OF THE; I NVE:NT I ON
1. Fleld of Invention
The present invention relates to a process for the
filleting of unbeheaded fish or of beheaded fish with the
collar bones still adhering to the body to be filleted
comprising the steps of performing belly filleting cuts,
back filleting cuts and rib cuts on a fish conveyed with
its tail end leading, and to an apparatus for performing
such process.
2. Description of Prlor Art
N0-PS 124 348 discloses a process for the beheading
or the severing of the collar bones of fish conveyed in
their longitudinal directlon tail forward, by means of a
pair of circular blades which are movable up and down and
oblique to each other with their cutting edges against the
feed direction of the fish.
In this process a beheading machine is not requlred
and personnel for loadlng a beheading machine with fish
are therefore not needed. Also a cutting location, which
arlses on the beheading of the fish at its head end and
at which the danger of bacterial infection or mildew
occurring exists with the intermedlate storage of the
fish before filleting, is not required. However, a major
disadvantage is that a special tool for the severing of
the head or the collar bones and special measuring and
control devices for the actuation of the tool are required
for the performancee of the process. Since the transport
of the fish past the tool for the severing of the head takes
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place by means of a push saddle, lt is not possible to
decapltate smaller fish, the gill chambers of which are
stlll disposed ln the range of the thrust saddle.
3. Object of Invention
It is one object of the present inventlon to be able to
cut free the fillets from small fish at a high yleld of flsh
meat without necessitating an additional tool.
SUMMARY OF THE INVENTION
According to one aspect of the present invention there
is provided a method of filleting unbeheaded fish or of
beheaded fish with the collar bones still adhering to the
body to be filleted, comprising the steps of performing
belly filleting cuts, back filleting cuts and rib cuts on a
fish conveyed with its tail end leading, wherein after
performlng the rib cuts the flllets are severed from the
fish by cutting the fish adjacent the collar bones and in
a direction inclined towards the roof of the skull leaving
at least one of the collar bone and the head on the remaining
bone skeleton.
Each rib cut may comprise an arcuate cut starting at
the end of the abdomlnal cavlty and a stralght cut extending
above one of the ribs and the vertebral projections, said
straight cut being at least contacted the severing cut.
Thereby, parting of the fillet from the bone skeleton
behind the collar bone is made possible.
Preferably each rib cut ls gulded above the flesh
bones up to the collar bone and is continued beyond the
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collar bone as the severing cut, thus separating the fillet
from the belly flap. This obviates the need for special
tools for carrying out severing cuts.
The rib cuts may enclose an angle of less than 180
towards the belly side of the fish while leaving the thin
parts of the belly lobes on the bone skeleton. This makes
the economical production of fillets free of flesh bones
posslble, even from small fish.
According to another aspect of the present invention
- 10 there is provided an apparatus for filleting unbeheaded
fish, or beheaded fish with the collar bones still ahering
to the body to be filleted, comprising conveyor means to
convey the fish, a pair of belly filleting knlves, a pair
of back filleting knives, and a pair of rotatable rib
cutting knives, wherein the axes of rotation of the rib
cutting knives are almost parallel to each other and
inclined in the conveying direction, each rlb cutting
knife is displaceable in a direction parallel to its
axis of rotation, and control means are provided operable
to displace the rib cutting knives in the dlrection of the
dorsal side of the fish at least on the arrival of the
abdominal cavity thereof. This apparatus enables the easy
and quick performance of the afore described process.
Advantageously each rib cutting knife may be provided
with a chamfer at the side thereof which in use faces the
belly side of the fish. This safeguards a faultless function
of the rib cutters.
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Support means may be disposed upstream of the rlb
cutting knives adjacent the cutting edges thereof. Thereby,
the cutting effect of the rib cutting knives is restricted
to the region of the abdominal cavity. Such support means
may be arranged either fixed to the apparatus or to yield
upon respective control.
The conveyor means may comprise a plurality of saddle
members each arranged to convey a respective fish and to
actuate the control means. The control means may be
actuated synchronously with the saddle tip. Thereby, control
of the rib knives is made possible in a simple manner.
BRIEF DESCRIPTION OF THE DRAWINGS
An embodiment of the present invention will now be
described in greater detail by way of example and with
reference to the accompanying drawings in which:-
Fig. 1 shows an axonometrlc lllustration of an
apparatus embodying the present invention,
Fig. 2 shows a cross-section through the apparatus
shown in Fig. 1 at the level of the rib
cutting knives for performing the lateral
cuts, and
Fig. 3 shows a fish with cutting lines of said
lateral cuts illustrated thereon.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the accompanying drawings, a fish
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travels along a path 1, with its backbone co-incidlng with
the line, in the direction of the arrow indicated in the line.
The path iis disposed in a frame (not shown) of a filleting
machine for fish. Disposed above and below the path 1 are
respective pairs of rotatably driven belly filleting knives 21
and 22, back filleting knives 31 and 32 and severing knives
41 and 42. Such tools as well as any guides which mav also
be necessary are well known in fish filleting machines. The
fish is conveyed along the path 1 by means of push saddles 51,
which are provided by way of example for different kinds of
conveyors 5, such as tail clamps or endless entraining belts
engaging at the flanks of the fish, and of wwhich only one
push saddle is illustrated. Downstream of and in the cutting
plane of the pairs of bellv filleting knives 21 and 22 and
back filletlng knlves 31 and 32 are palrs of mutually inclined
lower and upper bone guides 6 a~d 7 whlch engage into the
belly and back filleting cuts and which each in the region
of their upper and lower edges have gaps 61 and 71 for the
passage of the belly and back spines respectively of the
bone skeleton. Also there is a vertical gap 72 between
them for the passage of the lateral vertebral projections
or ribs. Between the pair of back filleting knives 31 and
32 and the pair of severing knives 41 and 42 there is a
rib cutter 8 comprising a pair of rib cutting knives 81
25 and 82 which are rotatable about axes 83 and 84 and whlch are
displaceable axially. The axes include an angle 85
corresponding to the angle of inclination 73 of the upper
bone guldes 7. Each rib knife and its associated axis is also
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so inclined that the downstream portion 87 of the blade is
lower than the upstream portion 88 and is so arranged that
that portion of each blade 86 wh:ich faces the bone guides,
in the lowermost setting of the respective circular knife
S lies just below the upper edges 62 of the lower bone guide 7
and almost touches the notionally downwardly projected outer
surface 74 thereof. Upstream of each knife 81 and 82 is a
cutting support 64 which is fast with the apparatus and
which covers the upstream portion 88 of the peripheral edge
of the knife 81 in the lowermost setting of the knives. Each
of the knives 81 and 82 at its underside 89 has a bevel or
chamfer 90 forming the peripheral edge 86 and is controlled in
the height position of its cutting plane by control means
(not shown) which are synchronised with the movement of the
conveying means and actuated ir. dependence on the setting of
the entraining members of the conveyor.
The apparatus operates as follows:
An unbeheaded, but degutted fish 9 is placed by its
abdominal cavity on the saddle 51 of an endless circulating
push saddle chain and conveyed by the saddle 51 to the pairs
of belly filleting knives 21 and 22 and back filleting knives 31
and 32 which open the fish at its belly and back side
respectively by filleting cuts guided to both sides of the
spokes. The back filleting cuts can extend up to and through
the skull of the fish, but they may also be interrupted by
driving out the back filleting knives at the head end of
the abdominal cavity. In its further advancing movement,
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the fish guided by means of the upper and lower bone guides 7
and 6, respectively, into the back and belly filletlng cuts
engages the knives 81 and 82 of the rib cutter 8, the
effective circumferential edges 86 of which are, however,
covered in their lower setting by the cutting supports 64
so that the fillet halves at the belly side are conducted
away over the knives 81 and 82. By a suitable pulse on entry
of the tip of the push saddle 51 into the region of the rib
cutters 8, the rib knives 81 and 82 are displaced axially
- 10 upwardly into a cutting plane, which selectably extends
just above the vertebral projections or the flesh bones
(pin bones~. By reason of their rearwardly inclined position
and/or the chamfer 90 at their lower side 89, each circular
knife 81 and 82 is deflected on engaging the rear edge 92 of
the collar bone 91 (supraclavicula) and the os posttemporale
forming one lateral skull bone and is displaced upwardly so
that the cut extends over the os occipitale closing the skull
off upwardly. The fillets thus gained are selectively free of
bones or pinbones. The bone skeleton carrying the head can
while maintaining the saddling-up be conducted to further
tools which for example make the detaching of the belly lobes
possible by cutting or scraping or permit the obtaining of
the collar bones with the flesh adhering to them. To make
the displacement of the rib cutting knives 81 and 82 more
certain, these can be actuated by an active control shortly
before the start of the deflecting motion in the sense of
a weight compensation.
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A major advantage of the lnvention and thus of the
embodiment descrlbed above by way of example is that beheading
of even small fish or severing of their collar bones is not
necessary before filleting sso that the cost incurred with a
beheading machine and its operation can be saved.
