Patent GB-582068-A (GB)
Title: Improvements relating to slicing machines
IPC: B26D1/14
Filed: 1944-07-19
Abstract: 582,068. Machinery guards. BERKEL & PARNALL'S SLICING MACHINE MANUFACTURING CO., Ltd., and THOMAS, H. July 19, 1944, No.-13790. [Class 80 (iv)] A slicing machine having a reciprocating carriage 3, Fig. 1, and a rotary knife 2 has an arcuate guard 15 so mounted that whenever the substance on the carriage is in the slicing station, the guard is spaced from the knife by a gap slightly greater than the thickness of the slice, and when the carriage is moved out of the slicing station the guard moves into the fullguard position. The guard 15 has an auxiliary guide rod 18 engaging a hole in the machine base 1 and a main guide rod 17 carrying a roller 21 that co-operates with a cam-like striker rail 22 on the carriage 3. The arrangement is such that during the slicing operation, the rail 22 urges the guard 15 away from the knife 2, while at the ends of the motion of the carriage the rail 22 leaves the roller 21 and the guard is urged to the full-guard position by a spring 19. Means are provided for adjusting the width of the gap between knife and the guard to be commensurate with the width of the slices: the regulator 10 on a shaft 11, which adjusts the feed-mechanism 7, 8, 9, by a rack and pinion device 13 and cam 14, also adjusts the position of the striker rail 22 along its guide 24, by turning the guide by cranks 25, 26. The guide carries a pin 28 which engages a helical slot in the boss 30 of the rail 22. In a modification, for a machine in which the carriage is reciprocated by hand and the thickness of the slice to be cut is determined by a gauge plate, the guard forms in effect a continuation of the gauge plate and is moved into and out of position by a roller co-operating with a striker rail mounted on the carriage. The gap between knife and the guard is varied according to the setting of the gauge plate. In another arrangement applicable to machines also having the slice thickness determined by the setting of a gauge-plate but in which the substance is fed to the knife under gravity, the guard is indirectly connected to the flywheel shaft of the machine by means which ensure that when the machine is started, the guard is moved into the slicepassage position and is moved back to the fullguard position when the machine is stopped. A further modification utilises electromagnetic means for moving the guard into the slicepassage position, on starting of the machine. Thus the guard 15, Fig. 10, is mounted on a guide 17, carrying a plunger 82 which co-operates with a solenoid 84 and an extension 87 of which coacts with a self-closing switch 88A, Fig. 12, and a second plunger 80 and extension 85 coacting with a solenoid 83 and self-closing switch 86A. A finger 90 rotatably but frictionally mounted on the flywheel shaft 71 of the machine is urged, when the shaft is stationary, by a spring 96 to engage a case 92 housing a self-closing switch 92A and self-opening switch 92B. When the machine is started, the finger 90 is carried round by the shaft 71 to operate the self-opening switch 91A, thereby energising coil 83 and moving the guard into the slicepassage position. When this position has been reached the extension 85 opens switch 86A and brings in a resistance 101 into the coil 83 circuit and reduces the current to an amount sufficient to keep the guard in its spaced position. When the machine is stopped, the spring 96 urges finger 90 anticlockwise to operate switches 92A. 92B thereby energising coil 84 to return the guard to its full guard position. When this position has been reached the extension 87 opens switch 88A and thus cuts off the electricity supply while the machine is stopped.