Patent GB-593792-A (GB)
Title: Improvements in or relating to calculating apparatus
IPC: H03M7/08
Filed: 1944-05-19
Abstract: 593,792. Counting - apparatus. NATIONAL CASH REGISTER CO. May 19, 1944, No. 9743. Convention date, Dec. 31, 1941. [Class 106 (i)] [Also in Group XL] Counting-apparatus comprises in combination a binary register which counts units of data, a scanning device to sense the reading on the register, a translator' controlled by the scanner and an impulse emitter controlled by the translator to produce denominational impulses in the scale of ten corresponding to the reading of the binary register, said impulses being registered by a scale-of-ten totalizer. In the embodiment described, the binary register comprises in each denomination a triggerconnected pair of high-vacuum thermionic tubes and the impulse emitter and the totalizer comprise gas-filled electric-discharge tubes. Binary register. Transfer and zeroizing mechanism. Each denomination comprises two vacuum electric-discharge tubes such as 54, 55, Fig. 2D, so interconnected that, when one tube is conducting, the other is perforce non- conducting and vice versa. The registration of zero in any denomination is signified by the fact that the upper tube 54 in that denomination is conducting, the registration of " 1 " being effected by causing the lower tube to conduct and the upper tube to cease conducting. The register described has twelve denominations of which only three are shown in Fig. 2D. The anodes of the tubes are supplied with positive potential from a line 21 and the screen grids positively energized from a line 28. The tubes have suppressor grids 49, normally earthed. A negative potential can be applied to the suppressor grids 49 of the lower tubes by switching means not shown in Fig. 2D. This stops conduction in all the lower tubes and leaves all the upper ones conducting so that the register is zeroized. The control grids 44, 48 are connected as shown and are supplied with a negative potential from a line 23. In the drawings, the shaded tubes 55, 65, 72 are assumed to be conducting. A positive impulse arriving at the input terminal 53 is transmitted to the grid 44 of the upper tube 54 so that this tube becomes conducting, whereupon its anode potential falls, this fall lowering the potential of the grid 48 of the lower tube 55 so that this tube then ceases to conduct. The registration in the lowest denomination has thus changed from " 1 " to " 0 " and, in the binary system, a transfer is then necessary. This is effected by connecting a point 46 in the anode circuit of the upper tube 54 to the control grids 64, 70 of the pair of tubes 65, 71 forming the next higher denomination. The potential of this point 46 falls when the upper tube 64 becomes conducting ; this results in a negative impulse being impressed on the control grids 64, 70, whereupon the conducting tube (e.g. 65) becomes non-conducting and the tube 71 commences to conduct, or vice versa. Whenever the upper tube 65 changes from a non-conducting to a conducting state, a negative impulse is transmitted to the tubes of the third denomination, and so on. Points such as 36 in the anode circuits of the lower tubes are connected respectively to output terminals 74 ... 85. When a lower tube is conducting, the potential of its anode-circuit point 36 falls. Hence, a low potential on any terminal 74 ... 85 is an indication that the corresponding denomination is registering " 1" and a high potential that.it is registering " 0. " Scanning and translating devices. Four wiper arms 95, 101, 135, 103, Fig. 3, are secured to a shaft 87 driven by a ratchet 88 operated by a stepping magnet 91 energized from a source 98 through wiper arm 95. When the device is at rest, the arm 95 rests on a contact 99. To start operation, a switch 100 is closed to connect the contact 99 via a ring lead 94 and line 93 to stepping magnet 91 and a make/ break switch 92 to commence the step-by-step rotation of the shaft 87. The rotation continues automatically until the arm reaches the starting contact 99 again, whereupon, if the switch 100 is open, action stops. The register output terminals 74 ... 85, Fig. 2D, are connected to contacts 43, Fig. 3, wiped by the arm 103 which is connected to the grid 123 of a vacuum electric-discharge tube 110. If " 1 " is being registered in a denomination, e.g. 24, of the binary register, the potential on the corresponding terminal 78 is low and this potential, when applied to the grid 110, causes the tube 110 to stop conducting. The ensuing potential rise at a point 111 in the anode circuit is conveyed to the grid 130 of a second tube 109 to cause this tube to become conducting. The wiper arm 135 moving in synchronism with the arm 103 is at this time on a contact wired to the terminal 178 of the 2<4> translating-switch magnet 207, Fig. 4D, whereupon a circuit for that magnet is completed from a line 214 connected to a supply 108, Fig. 4A. There is a translating-switch magnet such as 207 for each of the twelve denominations of the binary register. Six only of these magnets, 200 ... 211, are shown in Figs. 4A, 4D, 4F, each magnet operating four switches such as 352 ... 355 to complete control circuits for the decimal impulse producer. In the case of the 2<10> translating-switch magnet 206, Fig. 4D, since 2<10>=1024 in decimal notation, the circuits closed by the magnet 206 cause the decimal impulse producer to emit four units impulses, two tens impulses; and one thousands impulse. Delay switch. The terminal 360, Fig. 4F, supplying potential to the decimal impulseproducer is energized from a source 357 when a switch magnet 212 momentarily closes a switch 213, this being effected by an impulse generated only after the operation of any of the translating-switch magnets 200 ... 211. These latter move contacts such as 220, Fig. 4A, to connect a supply line 214 to the circuit 221 passing via the switch magnet 212, contacts 170, Fig. 3, condenser 184 to produce the impulse, wiper arm 101 and line 186 to tube 109. Decimal impulse-producer. This comprises a gas-filled electric-discharge starting tube S, Fig. 5A, two similar tubes. 251, 252, to produce thousands impulses, a thousands zero tube 250, a hundreds zero tube 253, Fig. 5B, five hundreds impulse-producing tubes 254 ...258, tens zero and impulse-producing tubes and units impulseproducing tubes, not shown in Figs. 5A, 5B. When the supply terminal 360, Fig. 5A, is energized by the delay switch described above, the starting tube S fires and this fires the thousands zero tube 250. The corresponding potential rise at a point 392 in the cathode circuit of this zero tube 250 is transmitted via line 394 and terminal 396, Fig. 4A, into a translating circuit controlled by the translating switches such as 234. If a translating-switch magnet such as the 2<10> magnet 206, Fig. 4D, is operative, the translating circuit will be switched to return the impulse to a terminal 455, Figs. 4F, 5A, connected by a line 456 to a point 410 in the grid circuit of the " 1000 " tube 251, causing this tube to fire to pass an impulse from its cathode circuit to a line 326, this impulse being amplified by a tube 503 and passed to the thousands-denomination input terminal 607 of the totalizer, the " 1000 " of 210 (=1024) thus being registered in decimal notation. The impulse from the cathode of the " 1000 " tube 251 is also sent via a terminal 388 into the translating circuit where it is switched to a terminal 452, Fig. 5B, connected to the grid of the hundreds zero tube 253 to fire this tube. The resulting cathode impulse passes from point 432 via line 434 into the translating circuit. Since there is no hundreds digit to be registered, the impulse is directed to the grid of the tens zero tube. The translating circuit is so switched by the operated 2<10> magnet 206 that the " 10 " and " 20 " tubes are then fired, followed by the firing of the "1," "2," "3" and " 4 tubes. As each tube (other than a zero tube) fires, an impulse is passed to a line such as 326 and thence through amplifying means such as 503 to the appropriate input terminal of the totalizer. Totalizer. This comprises four denominations each having a chain of ten digit-registering gas-filled electric-discharge tubes 000-900, Fig. 6c (hundreds denomination), and a similar transfer tube T (omitted from the thousands denomination). When a digit is being represented in any denomination, the corresponding tube (e.g. 800) is conducting, a point 628 in the cathode circuit thereof then being raised in potential, the rise being transmitted to the grid of the next higher tube, excepting in the case of the " 900 " tube, where the cathode connection is to the grid of the " 000 " tube and also to the grid of the transfer tube. When an impulse from the hundreds denomination of the impulse-producer is fed to terminal 306 connected through condensers 632 to the tube grids, only that tube (e.g. 900), the grid of which has been prepared by the potential rise from the cathode of the lower conducting tube, will fire. Each cathode is connected through a condenser such as 629 to a line 630 which is thus given a positive impulse when a tube fires, this impulse extinguishing the lower tube. The potential rise in the cathode circuit of the transfer tube T is conveyed by a line 672 to the input terminal of the next higher denomination.