Patent GB-545439-A (GB)
Abstract: 545,439. Calculating-apparatus. BALL, W., KEEN, G. P., and BRITISH ADDING & CALCULATING MACHINES, Ltd. May 30, 1940, No. 1254/41. Divided out of 540,313. [Class 106 (i)] A totalizer engaging control mechanism for a calculating machine comprises a number of control members, one for each totalizer, connected through pin and slot means to a single reciprocatable control bar and wherein the slots are arranged to permit movement of the control bar in a direction transverse to that of the reciprocating movement and to render any selected one of the connections operable to transmit the reciprocating movement while providing lost motion in the other connections. The machine shown in Figs. 3 and 4 has a differential rack mechanism similar to that described in Specification 540,283 and is provided with two totalizers 173 the spindles 174 of which extend through slots in partition plates and through inclined slots 178a in spring controlled slide bars 179, 180. The slide bars have pins 305,. 306 that co-operate with engaging control members or levers 303, 304, on rock shafts 309, 308, Fig. 6. The shafts carry arms with pins 310, 311 engaging L-shaped slots in a control bar 307 supported by links 314, 315 on the ends of interconnected levers 316, 317 and operatively connected to the main operating plate 335 which functions in association with a drag link 353 and release latch 345, to control the engagement timing. One or other of the pins 310, 311 is effective to select the appropriate totalizer for engagement by means of a selection lever 324 operatively connected to the link 315 in order to raise or lower the control bar 307. In a modified form of machine as shown in Fig. 5, two additional totalizers 222 are provided to engage with toothed portions 221 on the underside of the differential actuating racks 12. The selection of the appropriate totalizer is effected by differentially raising or lowering the control bar 307 which is provided with four differently shaped slots 298, 298A, 299 and 299A. Total and sub-total taking mechanism.-Depression of the total key 351 releases the latch 345 so as to permit engagement of the totalizer at the beginning of the forward stroke. The key also sets the draglink 353 into the path of a roller 348 on the operating plate 160 to cause disengagement of the totalizer at the end of the forward stroke. The sub-total key has no action on the draglink so that the totalizer remains in engagement during both strokes. In order to transfer a total from one totalizer to the other totalizer in Fig. 6, a transfer total key 369, Fig. 8, is depressed to operate the latch 345, the draglink 353 and a sliding plate 370. This plate has a pivot 375 carrying a C-shaped lever 376 on which is mounted a spring-controlled trigger 378 and a second lever 379. When the sliding plate is lowered the trigger is rocked into the path of a pin 386 on an operating link 162. At the end of the forward stroke, after the amount on, say, the rear totalizer has been set on the actuator racks, the pin 386 enages the trigger so as to rotate the C- shaped lever whereupon the spring 380 of the lever 379 is effective to lower a link 384 by the action of the lever 379 on the pin 385. The link 384 is attached at its upper end to the pivot connection of the levers 316, 317 whereby the control rod 307 is raised to condition the parts to effect selection of the front totalizer after the rear totalizer has been disengaged by the action of the draglink. The C-shaped lever, in its depressed position, engages a pin 387 on the latch member 345 to hold it in released position whereby the control bar 307 is free to move to effect engagement of the front totalizer. In these total taking operations the transfer conditioning member 206 is locked by the rotation of a triangular shaft 260 operatively connected by an arm and slotted link 501, Fig. 9, to the latch member 345. In subtract operations the link 501 is rendered ineffective on depression of the subtract key 506. Specifications 263,505, 288,672, [both in Class 106 (i)], 343,448, 343,473, 343,474, 343,475, 343,476, 352,958, 540,315 and, 540,320 also are referred to.