Patent GB-191416001-A (GB)
Title: Improvements in Calculating Machines.
Inventor: THOMPSON WILLIAM PHILLIPS
IPC: G06C11/00
Filed: 1913-06-17
Granted: 1914-08-17
Abstract: 16,001. Thompson, W. P., [Duco Adding Machine Co.]. June 17, 1913. Adding - apparatus; distinguishing - marks; controlling printing of zeros; zeroizing-mechanism.-Relates to a differentially-set, multiplebank, lever - operated, printing adding - machine, other sections of which are described in Specifications 14,044/13, 15,923/14, 15,924/14, [Class 100(iv), Typewriters &c.], 15,925/14, a n d 15,926/14, a n d consists primarily in zeroizing t h e totalprinting wheels by independent means and subsequently rotating them through a half unit to remove the zero types from the printing line. The totalizer pinions 372, Fig. 8, are actuated by means of rack-bars 325 which are differentially set by means of finger-plates (not shown) and before being positively returned are carried into engagement with the pinions by a bail 381. When any rack-bar is lifted into engagement for the first time in an addition, it raises the corresponding catch-lever 410, 412, thereby freeing a guided spring pawl 403, the tooth 408 of which, engaging a notch 409, Fig. 11, in the totalizer-wheel 103, produces a half-unit displacement thereof, so as to bring the zero type from the cleared position to the printing point. A similar movement takes place if any totalizer-wheel receives its first registration by transfer. Time is allowed for this half-unit displacement by arranging for the elevation of the rack-bar engaging bail 381, Fig. 10, in two stages by a cam 430 upon one of the secondary operating-shafts 420 of the machine, the bail being carried upon arms 389 in one with an arm carrying a pin 435, which is pressed outwards by the cam into the final raised position shown. The intermediate surface 432 of the cam corresponds with a sufficient raising of the rack-bars to liberate the half-unit pawls 403 for action, but without engagement of the rack - bars and pinions. Zeroizing is effected by holding a zeroizing-key 379, Fig. 3, depressed during an operation of the main handle, the key becoming locked by the setting of the first item and so remaining until a total has been printed. Rearward movement of any rack-bar rocks the bail 381, displacing the spring supporting-catch 392, and allowing the cross-rod 383 and the bail to descend and rock a shaft 515. An arm 529 upon this shaft raises an apertured plate 532 to lock a pin 535 and thereby the zeroizing-key against depression, in which position the parts are maintained by means of a hook 533 and pin 534, provision being made for the free rocking of the shaft 515. A total - printing operation, involving a rocking of the arm 540, displaces the hook and releases the clearing-key. From the rocking of a shaft 539, due to depression of the zeroizing-key 379, are derived by suitable link-work, the setting of a ' clear ' type ' C ' to the printing point, and the principal zeroizing - movements. Thus the pivoted side members 559, Fig. 4, are lifted to cause projection of a comb 377 mounted in the counterspindle 373 for engagement with internal lugs 376 upon the numeral-wheels when this spindle is subsequently rotated by the rocking of a subordinate shaft 570, brought about by a temporary coupling thereof to the main operating- mechanism maintained during displacement from normal of the main operating - bar 60. The rocking of this shaft effects the oscillation of a toothed sector 579 engaging a pinion 581 upon the end of the counter-spindle ; simultaneously, an arm 595 upon the subordinate shaft 570 rocks an arresting-edge 582 into the path of projections 583 upon the totalizer-wheel to stop them at zero position, after which the stopedge is released and returns by spring. Finally, from the same shaft is derived a movement of pivoted plates 601, Fig. 8, whereby the fingers 408 are reset and relatched, and a half-unit displacement of each totalizer - wheel is effected thereby in order to remove the zero types from the printing point. An interlock is provided between the shaft 539 rocked by the zeroizing- key and the detents 393 for the rack-bar engaging bail, whereby it is impossible to move one of the item finger-plates during depression of the zeroizing-key. The occurrence of transfer during zeroizing is prevented by a connexion from one of the comb - raising members 559 whereby a transfer-pawl restoring rod 486 is held against projections 487 upon the transferpawl carrying slides 444, the transfer mechanism being of the release type in which transfer accompanies positive resetting. An interlock is also furnished between the main-shaft rotated zeroizing-shaft 570 and the shaft 420 for raising the rack-bar engaging hail 381, whereby accidental movement of the bail becomes impossible during the zeroizing operation.