GB203351A - Improvements in connection with the key-boards of calculating machines - Google Patents

Abstract

203,351. Barr, J. M. M. March 1, 1922. Keyboards; adding and subtracting apparatus for monetary &c. values.-In key set and independently operated machines, the keys actuate devices adapted to receive the digit values set up and to hold the value for any desired interval of time and the subsequent operation causes the values to be transmitted by electromagnetic means to the totalizing-counter. Means are also provided for converting the digits set up by the keys into a different system of numbers before transference to the totalizing-counter and for modifying the values set up by the keys in certain denominational positions when there is subsequent depression of a key of a lower denomination. As shown applied to an electrically-operated machine for the conversion of British monetary units into the equivalent decimal values, each key (five only, viz. 7, 1, ¥, ¢, and 1/4 are shown) is associated with groups of contacts r representing the values 5, 2, 2, 1, which, depending on the denomination as determined by the carriage position, energize electromagnets or relays m<1>, m<2> to actuate the appropriate switches a - - g for the decimal positions V, W, Y, &c., in accordance with the particular value of the key. The switches close circuits to suitable ball-release mechanism and associated counting-mechanism. A distributor brush mounted on the carriage is adapted to co-operate with conductors X, S, D, F in the tens of shillings, shillings, pence, and fractions of pence positions to allow current to flow through the conductors and actuate the necessary switches. In the pence position the numeral key is temporarily latched so that the value may be altered by the subsequent depression of a fractions key. Each of the fraction keys has twelve arms, one for each of the digital keys 0 - - 11; the two shown are those associated with the " 7 " and " 1 " key, and certain contacts are designated " R," which signifies that any switch which may have been moved by the digital key is returned to its normal position on depression of the fractional key through corresponding return relays p to modify the value set up. The conductors o, o<1> are employed for addition and subtraction respectively, subtraction being effected by adding the complement.