Patent GB-868124-A (GB)
Title: Improvements in or relating to value registering apparatus
Inventor: DAVIS ROGER ARTHUR
Filed: 1957-08-12
Abstract: 868,124. Accumulators for statistical apparatus. INTERNATIONAL COMPUTERS & TABULATORS Ltd. June 30, 1958 [Aug. 12, 1957], No. 25374/57. Class 106 (1). An accumulator operable by timed electrical pulses derived from sensing record cards comprises a continuously rotating driving gear 2, a counter gear 4, an idler gear 6 in mesh with the counter gear mounted on a plate 8 and urged by spring 9 into engagement with the driving gear, a latch 11 normally holding the idler gear out of engagement, a magnet 12 operable by a start pulse to disengage the latch and allow the idler gear to engage the driving gear and cause rotation of the counter gear and a magnet 17 operable by a subsequent pulse to re-engage the latch, disconnecting the idler and preventing further rotation of the counter gear. The latch 11 is held in its alternative positions by a spring catch 20. The gaps between teeth of driving- gear 2 are much wider than the teeth of idler gear 6 to facilitate engagement in high-speed operation. The counter spindle 5 carries read-out contacts 24, Fig. 2, co-operating with contacts 25 and 28 on plate 27 and providing friction sufficient to hold the counter gear when the idler is disengaged. A second plate and cooperating contacts are provided for reading out the complement of the value registered. The addition magnet 12 is energized by the sensed pulse, e.g. in position " 6," and magnet 17 by a zero-position pulse. For subtraction the start magnet 12 is energized by a nine-position pulse and stop-magnet 17 by the sensed pulse, e.g. value " 6." A multi-denomination accumulator includes a number of units as described, each carrying a counting-mechanism and driven from a common shaft 1, carry means being provided between stages. Long-carry.-When a wheel is already standing on " 9 " a carry pulse from a lower denomination causes a carry pulse to be sent to the stage above. A circuit is provided to indicate that a wheel is registering " 9 " and to pass a carry pulse from the lower stage to the next higher stage. For this purpose there is provided a cam 29 on the counter spindle having low and high points 30, 31 and a cam follower 32 on a pivoted arm 33 of insulating material. A bowed toggle spring 37 urges the arm 33 to either of its two extreme positions and a nose 34 bears on spring arm 35. When the low part 30 of the cam is engaged by the follower, the arm 33 allows the spring 35 to contact pin 40 to indicate a long-carry condition. When the wheel moves between " 9 " and " 0 " positions the high part 31 of the cam causes the arm 33 to snap to the other position and spring 35 contacts pin 39 to indicate a carry position. The circuit through pin 39 is maintained until after the adding cycle is completed, the arm 33 then being reset by pin 42 to a central neutral position. In a modification the magnet 17 is dispensed with in an adding operation, the latch being reset to stop the counter wheel at " 0 " time by a pin on the driving gear 2. The magnet 17 is used in subtraction as before. The radix of the counter is changed by replacing gear 4 by another with a different number of teeth, say, twelve.