Patent GB-545438-A (GB)
Abstract: 545,438. Calculating apparatus. BALL, W., KEEN, G. P., and BRITISH ADDING & CALCULATING MACHINES, Ltd. May 30, 1940, No. 1253/41. Divided out of 540,312. [Class 106 (i)] A totalizer engaging control mechanism for a calculating machine comprises means including a reciprocatable control bar and draglink for establishing and interrupting a drive between the totalizer wheels and the differential actuating mechanism in accordance with the kind of operation to be performed. The invention is shown applied to a machine as described in Specification 540,283. A set of item totalizers is arranged circumferentially around a common actuating wheel and selection is effected by means as described in Specification 540,314. Engagement of the selected totalizer with the differential actuating racks is effected through intermediate pinions 49 by the longitudinal movement of a control shaft 81, Figs. 5 and 6. A grand total counter 82, Fig. 7, is also provided and is controlled for engagement with racks 65 or 12A on the main differential actuating racks by a displaceable control shaft 89. The operation of the shafts 81, 89 is under the control of the main shaft 43 and shaft 159. The shaft 159 carries a driving cam 159 which on the forward stroke rotates clockwise to free a spring controlled operating lever 335. The lever 335 is held against the action of its springs 340 by a release latch 345 with a depending arm 333 which is engaged by a roller 348 on the operating crank 160 at the end of the forward stroke. The operating lever 335 is released and displaces a control bar 307 to permit an arm 303 to rock. The arm 303 carries a cam 252 which cooperates with a similar 251 on the shaft 81 and moves the pinions 49 to totalizer engaging position. The engagement and disengagement of the grand total counter is controlled in a similar manner by a cam on the control shaft 89 engaging a similar cam on a slotted arm 522, Fig. 7, operatively connected by a link 519 to a bell crank lever 518 with a roller engaging a cam 515 on the main shaft 43. The engagement of the grand totalizer is effected at the commencement of the forward stroke and its disengagement at the end of that stroke is effected by a link 526 pivoted to the arm 333 of the release latch 345 and engaging a pin 528 on the bell crank 518. Total and sub-total operations.-With regard to the item totalizers the pinions 49 must be moved into engagement at the beginning of the forward stroke. For this purpose the total key 351, Fig. 5, on depression rocks the release latch 345 and frees the operating lever 335 for immediate action when the machine is operated. At the same time the stem of the total key depresses a draglink 353, journalled on a fixed pin 354 and pin and slot connected at 356 to the control bar 307, so as to position its hooked end 352 into the path of movement of the roller 348 on the operating crank 160 whereby the draglink restores the control rod 307 at the end of the forward stroke to disengage the totalizer. The roller 348 at the same time rocks a release lever 358 to free the depressed total key 351. In sub-total operation the draglink is not affected by depression of the sub-total key 365 so that the pinions remain engaged during both strokes. The grand totalizer is held out of engagement during these operations by the provision of a hook 530 on the rear end of the release latch 345 which engages a stud 531 on the bell crank 518. To take a total from the grand totalizer the grand total key 535 is depressed to move pin 521 on the link 519 radially of the arm 522 whereby a greater angular movement is imparted thereto when the bell crank 518 is operated to align the totalizer wheels 82 with the racks 12A. Depression of the grand sub-total key 537 through an extension 539 of the link 526 lowers the link to render it ineffective by reason of the shape of its slot 527 thereby permitting the wheels 82 to remain in engagement during the return stroke. The grand totalizer can be disabled by depression of a control key 532 to engage a shoulder on the bell crank 518 and hold it against operation. In total taking operations it is necessary to hold the differential racks in adjusted position after freeing the totalizer. For this purpose ratchet teeth on the racks are engaged by pawls 125 (not shown) with tails co-aperating with a triangular shaft 126, Fig. 9. The stems of the total and sub-total keys cooperate with a lever 452 to rock a latch lever 454 and free a bell crank 458. At the appropriate time in the cycle a projection 479 on a link 162 connecting the operating arms on the shafts 43, 159 rocks a lever 462 with a cam surface 465 so as to displace the bell crank 458 and rock the triangular shaft to operative position. In normal operations the keys are locked in set position by detent plates which are held by a triangular control bar, Fig. 10 (not shown), rocked from a cam on a rock shaft. A roller on the same cam co-operates with a bell crank and a lever arm to rock a shaft which operates the zero keys during a total-taking operation. Specifications 263,505, 288,672, [both in Class 106 (i)], 343,448, 343,473, 343,474, 343,475, 343,476, 352,958 371,988, 540,315 and 540,320 also are referred to.