| 摘要 |
509,907. Ciphering apparatus. SBRIESER, E. Oct. 1, 1937, No. 26565. Void. Convention date, Jan. 4. [Class 146 (ii)] In ciphering-apparatus, the depression of any key corresponding to a letter in the text both makes a final selection of the message key to be actuated and also a pre-selection of a set of message keys from which the next letter makes a final selection. Thus, in a machine with test keys a ... i and message keys A ... I, depression of key b will pass an impulse through contact m and pre-selected switch K<1> to solenoid n to actuate message key A and then pass an impulse through contact o to solenoid S<2> to set switch K<2> ready for the next test operation. The operation may involve one or two additional sets of switches so that one or two intermediate selections may occur. Instead of switches, variable resistances may be used in a Wheatstone-bridge circuit, the final current strength leading to the indicating or recording of a definite letter. The apparatus may have an additional key for deciphering. |
