Patent GB-472456-A (GB)
Title: Improvements in and relating to calculating machines
IPC: G06C23/04
Filed: 1936-11-17
Abstract: 472,456. Calculating - machines. MONROE CALCULATING MACHINE CO. Nov. 17, 1936, No. 31456. Convention date, Nov. 27, 1935. [Class 106 (i)] In a calculating-machine of the key-set independently-operated type, the differential mechanism comprises planetary gearing the various units of which are selectively connected by the setting means to the main driving mechanism, so that, upon the operation of this main driving mechanism, the final wheel of the planetary gearing receives the desired differential movement. A set of ten keys and four bars 51, 52, 53, 54, Fig. 3, is provided for each denomination, each key having an enlarged stem to cooperate simultaneously with all four bars. The bars are urged to the left by springs 67 and bars 51, 52 and 54 are normally held by the engagement of the stem of the O key with a projection 55, the O key being normally depressed. The depression of any other key releases the O key and either allows the bars to move one step to the left under the action of the spring 67 or pushes them one step to the right by the camming action of the key stem on the projection 55. Thus, when the 5 key is depressed, bars 54, 51, 52 are released for a one-step movement to the left and bar 53 is pushed one step to the right. The bars are pivoted to carriers 57 which move pinions 47, 48, 49 into mesh with one or other of two long pinions 44, 45, the latter pinions 44, 45 being rotated in opposite directions during a machine operation. The bar 54 is toothed to engage a pinion 73 on a stub shaft on the carrier 57 of the next higher denomination, the bar 53 of this higher denomination also engaging the same pinion 73 but being arranged to drive it in the opposite direction. The pinions 47, 48, 49 are geared to wheels 59, 60, 61 of a planetary gearing, Fig. 5, so arranged that the output wheel 80 is driven a number of steps corresponding to the algebraic sum of the movements marked on Fig. 3. Thus if bar 51 is moved to the right it couples 45, 47, 59 to give + 1 movement to 80, but if moved to the left, it couples 44, 47, 59 to give -1 movement to 80. Similarly, bar 52 couples 45, 48 60 to give + 3 to 80 when the bar is moved to the right and couples 44, 48, 60 to give -3 when moved to the left. The planetary gear is thus set to transmit any movement from 0 to 9 to the output gear 80, this being achieved in some cases by adding 1 in the next higher denomination and subtracting the requisite amount in the denomination concerned. The planetary gearing, Fig. 5, comprises the three receiving pinions 59, 60, 61, the output gear 80, two sets of planetary pinions 75, (one set only being seen in Fig. 5), and three rotatable planetary-pinion carriers 76. An alternative form of gearing is shown in Figs. 9 and 10. Long pinion 180 is rotated once, and long pinion 181 twice (in the same direction) during a machine operation. Pinions 183, 184, 185 are meshed with pinions 180, 181, upon the depression of numeral keys, by the means shown in Fig. 3. Pinion 183 is connected to a gear 187. Pinion 184 is connected through gearing 189 with a ratio 3 : 2 to the gear 187. Gear 187 has an eccentric hub 191 carrying a floating pinion 192 engaging internal teeth on an output gear 193. The floating pinion 192 also has projections 194 engaging circular recesses in a pinion 188 driven from the pinion 185. This gearing can be arranged to transmit twelve steps of movement to the totalizer wheels for British currency calculations.