Patent GB-215842-A (GB)
Title: Improvements in or relating to statistical tabulating machines
Filed: 1923-02-16
Abstract: 215,842. British Tabulating Machine Co., Ltd., (Tabulating Machine Co.). Feb. 16,1923. Statistical machines. - A machine for dealing with perforated record-cards previously sorted into groups has means for stopping the machine or for printing a total when the control holes of two successive cards differ, which means include in place of the usual second set of reading brushes mechanism which is set in motion when the control hole in one card is read and closes contacts exactly one card cycle later, coinciding with the moment when the hole in the next card is being read if the control holes are the same. If the control holes differ the relative lead or lag of the said mechanism in closing the said contacts causes the machine to stop or to print a total, for example by failing to break a motor-stopping circuit. When the control hole. in a card passing from the holder 2 to the box 8 is read bv a brush 5 a magnet 9 is energized, attracting its armature and by a link 10 rocking a latch lever 11 to the left to allow a lever 12 to move to the left also. thus opening contacts 13, 14 and closing contacts 14, 15. A shaft 16 rotating once for every two card-cycles carries wheels 17 having two sets of notches, each notch corresponding to a perforation point in any given column on a card. Loosedy mounted on this shaft 16 for each wheel 17 are three arms 18, 19, and 20, to each of which is pivoted a spring-actuated dog 21, 22, or 23 adapted to engage with the notches. A dog such as 21 locked in a notch on coming to the latched lever 12 is tripped out of engagement with its notch as shown in Fig. 1. The movement of the parts is so timed that when the lever 12 is tripped the dog held by it drops into the notch corresponding with the control liole read and rotates with the wheel 17; if there is no control hole the dog drops into a K notch. A cam 24 has fourhigh points and is rotated at such a rate that it is adapted to effect the relatching of the lever 12 by the lever 11 once for every index point in the column. An arm, such as 19, carrying a locked dog 22 engages, one cycle after the dog is locked to the wheel 17, a lever 26 and closes contacts 25. The arm 19 then continues until its dog is tripped by a lever 27, where it rests until a cam 28, rotated once each card cycle, rocks the lever 27 and allows the dog to relock in an S notch, the arm 19 then continuing until it is once more tripped by the lever 12. Each of the arms 18, 19, 20 passes through these stages, but in relative sequence, i.e., while the dog 21 is stationary at the lever 12, the dog 22 is travelling down to the contacts 25 and the dog 23 is being carried up to the latch 27. Coacting with the levers 12, 27 are latches 29 to prevent backward movement of the arms. A cam 30 withdraws the lever 11 ana unlatches the lever 12 once near the end of each cycle so as to permit the dog at the lever 12 to. lock in the K notch when there is no control hole in the column. When the control hole of a card comes under the brush, current passes from the brush to its block, and through contacts 13, 14 to magnet 9 which breaks contacts 13, 14 and momentarily makes contacts 14, 15 as above described. These contacts 14, 15 complete the motor-stopping circuit through an armature-contact 32 and magnet 33. Assuming that the previous card had the same control hole, at the time this is happening the dog and arm released by the previous card make the contacts 25. This energizes a magnet 31 and .attracts its armature 32 to break the motor-stopping circuit, so that the machine continues to run. If the control holes of two successive cards are not the same then the contacts 14, 15 and 25 do not make simultaneously, so that the circuit through the magnet 33 is not broken at the armature and the machine is stopped, or a total printed. The contacts 25 may be in a circuit that controls a registering or recording device; for some columns the contacts 15 are omitted, whereupon the magnets 9 function as ordinary counter-magnets and the contacts 25 operate the counter wheels in the known manner, but one card-cycle after the card is read.