Patent GB-701650-A (GB)
Title: Improvements in fish-dressing methods and machines
IPC: A22C25/00
Filed: 1951-05-21
Abstract: 701,650. Filleting fish. BAADER, R. May 21, 1951 [May 19, 1950], No. 11856/51. Class 28(2) Fish, especially large fish such as cod, are mechanically filleted after beheading and gutting, by pulling the fish, tail first, and belly down, with its backbone straight and in a single plane while filleting cuts are being made in it. The first filleting cuts are made by the fish being pulled along a pair of disc knives which slit up the underside from the tail root to the beginning of the belly cavity and of a depth up to the backbone and on each side of the lower spines of the backbone as in the lower part of Fig. 3. The second filleting cuts are made when the fish is pulled along a pair of upper disc knives which cut all the way along from the tail on each side of the upper spines of the backbone and reaching down to the backbone as in the upper part of Fig. 3. The fillets are thus lightly attached to the edges of the centre backbone and to the ribs. Thereafter ribbing disc knives cut the flesh from the ribs as in Fig. 7 and a pair of fingers detach the fillets from the backbone. Finally a pair of knives cut off the fillets from their remaining attachment at the tail. Fig. 8, joined to Fig. 8A shows a diagram of the machine in which the fish is placed, tail leading, into a feed trough 71, Figs. 8 and 15, which is tilted to contact the tail with a clamp, Fig. 11, which pulls the fish, tail first and belly down, past the various knives, the fish backbone travelling along the straight line X-X. The fish passes over a support 89, Fig: 8, detailed in Fig. 17, where it holds up a measuring lever 98. Fig. 8, which drops as soon as the head or end of the fish leaves it, this drop controlling mechanisms in accordance with the length of the fish as in Fig. 19. The distance between the tail and the beginning of the belly cavity is proportional to the length and width of the fish so that guides and ribbing knives operate just as the belly cavity reaches them. After leav- - ing the lever 98 the fish is engaged by a back guide 341 and then by a guide 340 which straightens the back fins. Below 340, another guide 485 straightens the lower fins. Further along, top and underneath guides 161, 162 operate, the guide 162 moving quickly into the arrived belly cavity and holding up the backbone at a constant height while lower filleting cuts from tail to the beginning of the belly are being made by a pair of rotary disc knives 198, Figs. 8 and 31. These cut s are spread open by a spreader 199. Then the top filleting cuts on each side of the backbone are made as it passes under a pair of disc knives 427 to which the fish is guided by a fin straightener 428 and a back guide 442. Spreaders 203 entering these cuts press the fillets away. from the backbone spines. In then passing over a support 505, the flesh is cut from the rib bones by two inclined knives 420, Fig. 39, the backbone only is engaged by a top guide 464, and the fillets are lifted from the knives by plates 610. Next the fillets are severed from the backbone proper by apparatus 580, Fig. 53, comprising fingers 210. The fillets then slide laterally down over plates 640 on to transverse conveyers 660, Fig. 8A. Finally, the tail end of each fillet is cut off from the backbone by an apparatus 670 with knives 221, Fig. 56 (not shown), so that the fillets can be carried away by the conveyers 660, while the backbone is carried onwards and under the machine until it is released by the opening of the tail clamp near the feed end of the machine. The various mechanisms are operated. by cams timed by the measuring lever to come into action as the required part of the fish is being pulled along to be cut, &c. by the knives. The feed trough 71 is made to rock as well as reciprocate as in Fig. 15 so that it clears and overtakes the travelling tail clamps and pushes the tail into the closing clamp, Fig. 11. The fish is initially pushed by hand along the trough until its tail emerges from between side plates 72 which can move apart equally. The fish to be measured is first pulled over pairs of support plates 319, Fig. 17, forming slots between them. Slot 91 receives and straightens the tail while upstanding side pieces 90 support the belly, the other plates 92 are rocked down to facilitate the passage of the fish to the next set of guides, Fig. 19 shows the measuring mechanism with the feeler shoe 322 bearing on a fish in which the pawl of an automatic latch 109 engages a rack 108 to an extent in accordance with the length of the fish to bring the filleting knives into operation at the right position of the fish. The fish then passes between lower fin straightening guides 485, Fig. 24 (not shown) and an upper saddle shaped guide 340, Fig. 27 (not shown) both being automatically moved up or down respectively by cams to let the tail clamp pass: This guide bears down on the fish passing under the V of the saddle shaped guide. A pair of rotary disc knives 198, Fig. 25, make the first filleting cuts. The fish is guided to these knives by a sadde shaped guide 161 which rides over the back, and an under guide 162. 161 and 162 move apart on engaging the tail. The. cutting position of the knives 198 is determined by the positions of adjustable stops 202, Fig. 33 (not shown). The guides 161, 162 are interconnected s o that on engaging the tail end they move apart until the belly cavity arrives at 162 which is then positively moved into the belly cavity to press and hold up the backbone during downward cutting by the upper filleting knives. This is effected by a cam 173, Fig. 25, on a shaft 143 which is controlled by the measuring lever 98. The knives 198 are automatically spaced apart, Figs. 31 and 32 (not shown), in accordance with the size of the fish, to cut close to the underspines but move futher apart at the belly cavity which is pulled over them without any cutting. Then upper knives 427 make filleting cuts down the back of the fish on each side of the upper spines. The knives 427 are spaced apart automatically in accordance with the measured length (and proportionate thickness) of the fish by inclined-tooth co-operating sleeves 454, 455. A similar space adjustment method is applied to the other pairs of knives. The cuts made by the upper knives 427 are immediately entered by a flesh spreader 203, Fig. 37 (not shown) which push the upper cuts away from the backbone so that the upper spines are engaged between the next guide 464, Fig. 39. The sides of these guides are urged in by spring.481 to,centre the upper spines accurately for positioning the fish for the ribbing knives 420. The friction of the sides is lessened by inset free discs 470. Other spreaders 421, Fig. 33 (not shown) have entered the lower cuts made by the first knives 198 and hold up the belly flaps for the ribbing knives. The fish is spread out over two sets of guide plates 507, 186, and 187, Fig. 50, hinged together so that the outer plates 186, 187 are lowered to allow the ribbing knives to cut the belly flaps just clear of the rib bones. The two sets are spread apart automatically as the knives 420 are spread apart to suit the size of fish, such spreading motion having a delay action as in Fig: 31, so that their automatic spread takes place after the upper filleting knives have been adjusted. The spreading is effected by inclined tooth sleeves on a shaft 498, Fig 31. The fillets now attached'to the sides of the backbone are severed by being pulled against two fingers 210, Fig. 53. which are on mechanism to raise the whole device clear of the tail clamp and then lower them into fish engaging position. The fillets are completely detached by disc knives 221, Fig. 8A and Fig. 56 (not shown). These knives are swung down on to each side of the backbone to cut the fish with an outward separating movement to assist in throwing the tail ends of the fillets on to the conveyers 660. The backbone and ribs and tail is conveyed by the tail clamp to the lower run of the clamp conveyer where it is then released. In the case of fish having a different ratio of belly length and depth to the actual length of the fish, appropriate cams can replace the others to suit the type of fish being dealt with. Specifications 701,679 and 701,680 are referred to.