Patent GB-556239-A (GB)
Title: Improvements in or relating to calculating machines
IPC: G06C11/02
Filed: 1942-01-13
Abstract: 556,239. Calculating-apparatus. FELT & TARRANT MANUFACTURING CO. Jan. 13, 1942, No. 534. Convention date, Feb. 24, 1941. [Class 106 (i)] In a calculating machine, to minimize errors in reading the results registered on the numeral bearing elements, indicating devices are provided which are operable to distinguish the denominations registering the result from every other denomination. The invention is shown applied to the " Comptometer " type of machine. The indicator devices are associated with the numeral drums and are operated upon actuation of any one of the numeral drums to provide a visual indication in the actuated denomination and in the lower denominational orders. Depression of a key in any column operates the corresponding numeral drum 38, Figs. 3, 6 and 8; in the known manner. The drums 38 are of hollow construction and have a peripheral flange bearing the digits 1 to 9 and a ciphershaped aperture 138. In the zero position the apertures 138 are aligned with the usual sight apertures 139. Within each drum is mounted an indicator device 141, Figs. 11 and 14, comprising a sector-shaped arm 142, a resetting arm 143, and a latching arm 144. The sector 142 is formed with flanges 145, 146 ; the flange 145 serves to blank out the cipher aperture and is given a colour similar to that of the flange of the numeral drum ; the flange 146 is given a contrasting colour and serves to register a zero to the right of the highest significant digit. The arm 143 has a shoulder 147 to co-operate with a resetting rod 177 and the arm 144 has a shoulder 148 to co-operate with a latching device 155. Each indicator device 141 is urged in a counter-clockwise direction, Fig. 11, by a spring 153 engaging a recess 154 at the rear of the arm 142 and secured to an arm of the corresponding latch lever 132 of a transfer mechanism cut out device of the type described in Specification 551,994. The latching device 155 comprises a long arm 156 and a shorter arm 157 laterally spaced from the long arm for engagement with the shoulder 148. An extension 161 of the arm 157 engages the long arm of the adjacent lower denomination. The long arm 156 of each latch carries a roller 165 which in latching position, extends into the path of movement of the zero stop pins 97 on the associated gear wheel 32. When any value is entered in a particular denomination the associated gear wheel 32 is rotated counter-clockwise in Fig. 8 and the latch 155 is rocked to free the indicator device and all those of lower denominations so as to move them from blanking to indicating position. The indicator devices are returned to normal blanking position on zeroizing the numeral wheels by the operation of clearing means. Manipulation of a zeroizing lever imparts a limited rotation to a shaft 78 thereby rocking the frame plates 64 carrying the gears 32 which are disengaged and operate spring means (not shown) to restore the numeral wheels to zero position. At the same time the shaft 78, through links 171 and bell cranks 172, pulls down links 176 thereby swinging the resetting rod 177 and its supporting arms 178 forwardly to engage the resetting arms 143 and restore the indicator devices.