Patent GB-176392-A (GB)
Abstract: 176,392. White, A. E., (Jones, G. B.). Oct. 6,1920. Multiplying and dividing apparatus.-Relates to machines provided with multiplicand and multiplier keyboards and with discs notched to represent the partial products of the digits 1 - - 9 by themselves and consists in the provision of a decimal key in the multiplier key bank which is depressed in the natural sequence, of discs with notches to represent both the units and tens of the multiples of two digits, and of two totalizing counter carriages, one of which accumulates the successive partial products and the other may register the total of such accumulated products. The discs 44 are arranged in groups of five and the multiplicand keys serve to select the discs and the multiplier keys determine their rotation. Depression of a multiplicand key 7 through an arm 85 rocks a corresponding shaft 87 and causes a pin 88 thereon to raise or depress a corresponding lever 89 of a set of five upper and four lower levers, pivoted at 90 so that a floating rack 49 meshing with teeth on the appropriate disc is pressed into engagement with a part 50 on a slidable frame 51 reciprocated by means associated with the main operating mechanism. The extent of this movement is limited by one of a series of stops 57 moved into the path of a crossbar 59 on the frame 51 when a multiplier key 8 is depressed. The movement of the rack 49 rocks a bell-crank lever 92 and locking arms 95, 96 to free the bars 98, 99 secured to racks 120, 100 respectively which on the operation of the machine are caused to move radially until arrested by the units and tens notches presented to them. The movement is effected by means of a corresponding rack 109 connected by a spring 484 to links 482, 481, and an arm 478 on the main shaft 449 and which carries a pinion 107 gearing with racks 102, 120, the rack 102 being geared through a pinion 101 with the rack 100. The movement of each rack 109 is communicated to a pinion 131 integral with a gear-wheel 133 which engages a pinion 134 mounted in a sleeve 135 which carries a central pinion 138. The central group of pinions 138 are in engagement with pinions 139 which are therefore rotated on the forward and return stroke of the main operating-handle: during the latter stroke pinions 153 on a. laterally movable carriage are lowered into gear therewith and are thereby rotated to register the partial product. The fractional units are similar to the groups of racks for the digits and the fractions are set up by depressing the particular key which results in selecting the appropriate discs representing the decimal equivalent in the three right hand denominational groups. In the case of the fractions <1>/3 rd and <2>/3 rds the discs are so designed that an extra unit is carried into the product, the steps or notches thereof representing multiples of 3, 3<1>/3, and 6<2>/3 respectively. Transfer mechanism.-Transfer is effected by permitting the pinions 139 to move one or more additional steps beyond the normal position. Pins 154 on the pinions 153 rock an escapement lever 144 to allow a slotted plate 140 to rotate to the extent of one or two ratchet teeth 143 and thereby move the end of the slot 141 so that a pin 142 working therein on the pinion of next higher order allows it to rotate beyond the normal position. The transfer parts and the racks 109 are restored to initial position at the commencement of the subsequent operation by means of a restoring rod 472 carried by rocking levers 470 connected t oa shaft 463 associated with the main shaft 449. Totalizing-counters. - The " intermediate " carriage for accumulating the partial products is arranged to move transversely across the machine step by step by means of an escapement mechanism and the main carriage for the total product is normally stationary, but is adapted to move in unison with the intermediate carriage after the depression of the decimal key as described below. The intermediate carriage comprises side members 167 carried by links 169 one of which is provided with a pin 171 normally engaging a central step 178 of a sliding plate 174 to hold the carriage in mid-position. Movement of the plate 174 to the left in Fig. 44 by means of a shaft 183 associated with the main shaft 440 causes the pinions 153 to engage the pinions 139, while a movement to the right effects the engagement with pinions 205 on a shaft 204 mounted in the main carriage 200. A step-bv-step movement may also be imparted to the carriage by repeated depressions of the zero multiplier key by means of a link 509 operatively connected to the key and to a link 496 connected to the bell-crank lever 500 which carries the pawl 503 engaging the carriage rack 165. The carriage is restored to its initial position by depression of the addition key 9 which imparts an excessive movement to the bell-crank lever 500 to disengage the retaining pawl 505 and the advancing pawl 503. On the depression of the decimal key the two carriages are locked together by means of a bellcrank lever 593 supported on the main carriage being caused to engage one of a series of notches in a bar 598 secured to the intermediate carriage; the lever 593 is rocked by an arm 592 and is held in locking position by a bar 595 provided with a notch 594 into which the bell-crank lever can fall when the carriage is returned to normal position. The main totalizer pinions 209 are actuated through gearing 206, 208, and reversing- pinions 210, 211 are provided to enable a product to be added to or subtracted from the accumulated amounts. Associated with the pinions 205 are pinions 212 connected thereto by ratchet mechanism so that the pinions 205 drive the pinion 212 in one direction to set the pivotally mounted type frames 216.