Patent GB-405421-A (GB)
Title: A machine for filleting fish
IPC: A22C25/16
Filed: 1932-10-29
Abstract: 405,421. Filleting fish. ROWTON, H. S., and ROWTON, J. L., 7, Devanha Gardens, Aberdeen. Oct. 29, 1932, No. 30399. [Class 28 (ii).] In a machine for removing the flesh from the prismatic portions of the backbones of decapitated and eviscerated fish, a stationary doublebladed tool 12 is used, each blade 18 comprising a pointed end 19 to enter the flesh of the fish at the two sides of the prismatic portion and having an elongated portion 21 extending rearwardly therefrom, which portion gradually increases in width towards the rear and has a curved cutting edge 23 outwardly splayed to conform with the shape of the backbone and to cut through the flesh close to the sides thereof. The fish may be conveyed on a rotary table or drum having its axis vertical, horizontal or inclined, or may be carried on a conveyer belt, which, if underneath tools are used, is slotted to allow the tools to reach the belly of the fish. If a rotary drum conveyer is used, the blades 18 are curved to conform with the curvature of the drum. The fish may be held stationary and the tools traversed over it. As shown in Fig. 1, the fish is conveyed past the tools by a flat conveyer 10, and is slit along each side of the oval-sectioned part of the backbone by spaced disc knives 13 mounted, in known manner, so as to be lifted automatically when they reach the prismatic part of the backbone. The knives 13 may operate simultaneously or in sequence. The blades 18, which may be arranged side by side, or one in front of the other, are sharpened top and bottom at 21<a>, 21<b>, as shown in Fig. 5, adjacent the tip 19. The cutting-edge 21b is continued backward as an edge 24<a>, 24b which, in the modification shown in Fig. 2, is blunt to avoid severing the back of the fish. In Fig. 10, the blades 18 are modified by the provision of a rear cutting-edge 24b which severs the back and divides the fish into two fillets. The upward sweep 23 is sharpened as shown in Figs. 5, 6, 7, to cut the flesh away from the sides and backbone. The blades 18 are carried by a member 17 which bridges the conveyer 10, and their height above the conveyer 10 is adjustable by a wing nut 27. The blades are also adjustable as regards their mutual separation. An arm 28, 28<a> is pivoted at 29 to a bracket 30 on the blade support, and carries a thin extension 31 which projects between the disc knives 13. The arm is normally swung downwardly by a spring 36 until a limit stop is reached, and the arm is connected by a chain 35, passing over a pulley, to the arm carrying the knives 13, the arrangement being such that when the knives 13 move upward the extension 31 moves downward, presses on the fish and prevents it from leaving the conveyer 10. When the knives 13 descend, the extension 31 rises. The fish is retained on the conveyer, when the blades 18 are operating, by a toothed disc 32 positively driven at a speed substantially equal to, or slightly greater than, the conveyer speed, by a flexible shaft. When blades 18, of the form shown in Fig. 2, are used, the backbone is finally removed, in known manner, by angularly related disc knives 37.