Patent GB-676813-A (GB)
Title: Improvements relating to the mechanical dressing of fish
IPC: A22C25/16
Filed: 1950-01-18
Abstract: 676,813. Fish dressing. FISADCO, Ltd. Dec. 29, 1950 [Jan. 18, 1950], No. 1354/50. Class 28 (ii). The back-bone of a herring &c. is cut out by making a first longitudinal cut 22, Fig. 12, from the belly by one disc knife 20, Fig. 11, and then making a second longitudinal cut 28, Fig. 14, by a succeeding second disc knife 24, Fig. 13, the fish being so canted and deformed by guides 40 and 78 &c. that the cuts pass close on opposite sides of the back-bone 12 and meet between the back-bone and the back of the fish. Each previously beheaded fish is carried round in the peripheral groove of a rotated drum 2 and is drawn tail first into contact with the various cutting and gutting tools, the first of which, not described, cuts a thin strip 10, Fig. 10, off the belly, thus exposing it to another tool, not described, to remove the guts. Thereafter the fish is slit by a first rotated disc knife 20, Fig. 3, and then by a second disc knife 24. The knives are mounted in adjustable housings eccentric to their fixed driving spindles. Instead of so removing the back-bone, the fish may be cut right through to the back by a third knife (not described) entering one of the previous two cuts, the fillets then being pulled away from the back-bone. In making the first cut 22 the fish belly is supported by a V-section yielding guide 40 with a slot 41 for the knife 20. The guide 40 is canted upwards above the plane of the back-bone to deform the fish during cutting so that when cut and released the shape of the cut 22 is curved at the back-bone. This first cut passes through the lower ribs 14. The cut 22 is opened out by a succeeding yielding guide 52 to allow the guts to be removed by a tool lying between the knives 20 and 24. For the second cut 28 the fish is drawn round by its tail on the rotating drum 2 until a fixed plate 26 enters the first cut, and a ramp 88 on 26 deflects up the upper part of the fish above the knife 24. The upper half of the fish is pressed downwards by a spring loaded upper guide 78, Fig. 13, so that the back-bone is below the centre line 50 of the groove 4 in the drum and thus canting the fish downwards so that the knife 24 which is also below the centre line, makes the requisite cut 28, Fig. 14, to meet the previous cut behind the back-bone and so free it for removal by the grooves 98 on the underside of the knife. The back-bone is accommodated in a recess 94, Fig. 6, from which knife grooves 98 eject it tangentially as at 100, Fig. 5 (not shown). The knife 24 is given a slight movement from and to the drum by a cam as described in Specification 676,814 to allow for the varying distance along its length of the back-bone from the back of the fish. Allowance is also made for variation of the thickness of the back-bone in Figs. 7 to 9 (not shown) in accordance with the size of the fish by varying the clearance between the knife 24 and the plate 26 in accordance with the above movement of the knife away from the drum 2. The second knife 24 also severs the back-bone from the tail root leaving a stub of back-bone at the tail. This is done owing to the bend up of the tail by the tail grippers. This break may be omitted by completing only the first part of the cut 22 and then finally the second part through the back by a third knife. The wall of the groove 4 in the drum 2 is serrated to improve its rotational pull on the fish. Specification 676,815 also is referred to.