Patent GB-1342881-A (GB)
Title: Food slicing machines
IPC: B26D1/143
Filed: 1970-03-20
Abstract: 1342881 Food-slicing machines HOBART MFG CO 5 Jan 1971 [20 March 1970] 13517/70 Heading A4C [Also in Division F2] Slicing Machine: In a slicing machine, an interlock mechanism permits a tray 100, Fig.2, to be removed only when a gauge plate (65) Fig. 1, (not shown) is locked in the position where its surface is flush with that of a rotatable knife 35, Fig. 3, and a carriage 85, Fig. 8 is at one end of its stroke of reciprocal movement. A second interlock mechanism permits energizing of a motor 25 to rotate the knife 35 only when a removeable guard 45 is fitted over the knife and a third interlock mechanism prevents operation of the motor 25 until the third interlock mechanism is operated. The second and third interlock mechanisms comprise switches 58, 146 and 158, Fig. 11, in series with the motor 25. Carriage: The carriage 85 is slidably carried by rods 84 and includes the L-shaped tray 100, having below one wall 103, a block 105 with a downwardly extending locking plate 108 with a cam slot 109. The locking plate 108 slides within a slot (96) Fig.6, (not shown) on the carriage 85 below a recess 118 in a rotatable locking bolt (110) which carries a retaining screw 116 in a slot (115), has a downwardly projecting pin 120 and is urged by a spring (122) towards the end with a handle 112. After the plate 108 is slid below the bolt (110), it is rotated to clamp the plate 108, whereupon the pin 120 engages the slot 109 and causes the bolt (110) to move in the direction to compress the spring 122. A hole 123 in the bolt (110) is then aligned to receive a locking rod 124 which is urged upwardly by a spring 125. The rod 124 is connected to a lever 126 which is connected by a link rod 128 to a rocking plate 130 pivoted about a pin 132 and having tabs 134, 136 adapted to engage an extension 138 of a lever 70 pivoted on a pin 72 and having an extension between adjacent flights of a worm 74 on a shaft 76 and rotatable by a knob 78. Interlock Mechanism: The plate 130 can engage the lever 70 only when it is in a position such that a slot in the lever 70, which has a pin 68 projecting from one of a pair of rods 66 passing through it, moves the pin 68 so that the gauge plate (65) carried by rods 66 is flush with the knife 35 and when the carriage 85, 86 is at the end of its stroke. When this occurs the plate 130 pivots so that the tab 134 engages the extension 138 and prevents rotation of the worm 74 and the rod 128 moves upwardly and retracts the rod 124 from the hole 123 so that the bolt (110) may be rotated and the tray 100 removed. The interlock cannot be released until the plate 108 is re-inserted under the bolt (110) and clamped, since there is no cam slot to align the hole 123 with the rod 124, hence the gauge plate (65) remains locked flush with the knife 35 when the tray 100 is removed. Knife: The slicing knife 35 is mounted on a tubular shaft 28 which is rotatably mounted on anti-friction bearings 29 and has a gear 33 which engages a worm gear 26 on the output shaft of the motor 25. The knife guard 45 is mounted at the upper end of a rod 46 which extends through the shaft 28. A conical recess 48 is formed in the lower end of the rod 46 and receives a lock pin 51 mounted for rotation by a knob 52. The lock pin 51 is threaded into a sleeve 54 which is urged against a surface (61) Fig. 4 (not shown) by a spring (59) and which carries a pin 56 which operates a switch 58. When the pin 51 is retracted, the guard 45 may be removed. If the knob 52 is then rotated, the pin 51 threads into sleeve 54 until it reaches the end of its thread. The sleeve 54 remains adjacent the surface (61) so that the pin 56 holds the normally closed switch 58 open. When the rod 46 is inserted in the shaft 28 and the knob 52 is rotated, the lock pin 51 threads intothe sleeve 54 until it enters the recess 48 and engages the rod 46. Further rotation of the knob 52 causes the sleeve 54 to move away from the surface (61) thereby retracting the pin 56 and allowing the switch 58 to close. Switch: A main control switch 146 has a toggle 147 between collars 148 on a rod 150 with a knob 152 at one end projecting from the housing 15. A sliding collar 154 is urged by a spring 155 against the toggle 147. When the knob 142 is pulled to operate (close) the switch 146 one of the collars closes a normally open switch 158. If the guard 45 is in position, a relay coil (160) Fig. 7, (not shown) is momentarily energized by supply lines (L 1  L 2 ) and closes contacts (162) to hold the circuit closed after the knob 152 is released and the switch 158 re-opens. The tray 100 has a guard 140, a gripper 142 mounted on an arm 143 slidably supported on a rod 144 and carrying a clear plastic shield 145.