Patent GB-1034430-A (GB)
Title: Improvements in machines for tenderising meat
IPC: A22C9/00
Filed: 1964-06-16
Abstract: 1,034,430. Tenderising meat. J. P. TAMAIN. June 16, 1964 [June 21, 1963], No. 24905/64. Heading A2U. A machine for tenderising meat comprises an assembly of thin metal, e.g. steel, blades disposed parallel to each other at small distances apart. The assembly is reciprocated, by mechanism driven by an electric motor, so that the blades, during a working cycle, penetrate into and are withdrawn from a piece of meat located on a support. The associated electric circuit includes a contactor, which is actuated automatically, during rotation of the motor or a shaft driven by it, to stop the motor when the blade assembly returns to its starting position after completing said working cycle. The blades 22b, Fig. 7, constitute the tines of spaced, comb-like plates 22a, which are secured together to form a blade-block 22, Figs. 1 and 7. The machine has a frame 1 with two sleeves 5, which slidingly accommodate the two vertical rods 6 of a vertically movable rectangular framework having a lower cross-piece 7 and an upper cross-piece 8, on which are mounted the electric motor 29 and a shaft 30 driven therefrom. A shaft 11 is journalled in the frame 1 and carries a toothed wheel 14 which engages a chain 15 secured to the wheel 14 and to the cross-piece 7. The rectangular framework is urged upwardly by springs 9, but can be lowered by turning the lever 13 secured to one end of the shaft 11. The shaft 11 also carries a ratchet wheel 43 co-operating with a pawl 44, Fig. 5, pivoted to the frame 1 and urged from the wheel 43 by a spring 47. On energization of an electromagnet 49, its armature 50 moves the pawl into locking engagement with the teeth of the wheel 43. A cross-head 19, Fig. 1, resting on springs 20 is slidingly mounted on the rods 6 and carries the blade-block 22. A connecting rod 32a is pivoted to the cross-head 19 and to a contactor disc 31 functioning as a combined crank-plate and cam mounted on the shaft 30. The blades 22b of the block 22 co-operate with a grid 33 comprising parallel horizontal bars 34, Fig. 5, between which the blade plates 22a can pass. The grid is removably mounted in a frame 35 supported by two rods 36 passing through the cross-head 19 and adjustably secured to a cross-piece 39, which has pivoted ends 41 embracing the rods 6. An operator places the piece of meat 3 on the support 2, e.g. a removable wooden slab, and moves the lever 13 downwardly to lower the frame 35 into contact with the meat. He then presses a button 64 to close a switch 62 and energize electromagnets 61, 49 and 72, Fig. 9. The electromagnet 61 now moves part 60 of a switch 58 against the action of a switch-opening spring (not shown) to connect the motor leads 59 to the power supply leads 57. The energized electromagnet 72 releases the band brake of the motor, so that it starts to drive the shaft 30 and move the cross-head 19 and blade-block 22 downwards, The roller 52 of a feeler 51 contacts the larger radiused arc of the disc 31 and thus closes a switch 55 to maintain energization of the said three electromagnets. The operator can now release the button 64 and the lever 13, since the energized electromagnet 49 maintains the pawl 44 in locking engagement with the ratchet wheel 43. After half a revolution of the disc 31, the blades 22b have penetrated fully into the meat. During the next half-revolution of the disc 31, the blades are withdrawn from the meat, which is held down and stripped from the blades by the frame 35, which is prevented from rising, because the ends 41 of its supporting cross-piece 39 pivot into locking engagement with the rods 6. The roller 52 comes into contact with the arc of smaller radius on the disc 31, and the feeler 51 opens the switch 55 and stops the motor 29.