GB490595A - Improvements relating to devices for registering the progressive totals of numbers added or subtracted in succession - Google Patents

Abstract

490,595. Calculating-machines. ROSS, C. E., and PERKS, T. E., (trading as ROSS & PERKS). Dec. 17, 1936, No. 34724. [Class 106 (i)] In adding-machines comprising a rotatable member 103 having a number of circumferential stop members 118, an abutment member in a fixed position, and fixed setting means for selectively projecting the stop members in accordance with the number to be added or subtracted, the stop members are projected by springs 119 when the setting means release catches 113. The setting means comprise electromagnets 109, arranged on a ring 110 behind the member 103 and operating on armatures 112 on catches 113. The abutment referred to above is positioned adjacent to the magnet corresponding to zero and in the initial position of the apparatus the member 103 is held in its zero position against spring 108 by the stop projected by the zero magnet engaging the abutment. When a number is to be added the electromagnet corresponding to the number is momentarily energized to raise the stop opposite thereto and a magnet is also energized to remove momentarily the abutment so that the member 103 is rotated by spring 108 to bring the newly raised stop into contact with the abutment. An indicating device connected to the member 103 is thus shifted at each operation by an amount corresponding to the position of the magnet energized, and thus the total of the operations is indicated. The apparatus may be used to register hits on a target provided with contact devices in its various zones that can be operated by a missile.