Patent GB-752591-A (GB)
Title: Improvements in or relating to calculating machines
IPC: G06C19/02
Filed: 1954-05-14
Abstract: 752,591. Calculating-apparatus. FELT & TARRANT MANUFACTURING CO. May 14, 1954 [May 27, 1953], No. 14169/54. Class 106(1). A split-accumulator machine is provided with means for confining significant zero indication to the appropriate section of the accumulator when set for split operation. The invention is applied to the known type of key-responsive machine wherein an ordinal gear sector 26 is differentially positioned downwardly under control of a column of keys 25, return movement of the sector under spring action being transmitted through gearing, including a carry gear 32, to a corresponding accumulator wheel 38. Forward actuation of a zeroizing handle 71 rocks a frame 64 to detrain the carry gears which are then effective under power of their springs to zeroize the accumulator. Re-engagement of the carry gears occurs immediately upon further key actuation and before return upward movement of any gear sector 26. The machine includes means, as described in Specification 556,239, for indicating significant zeros in the totals, the accumulator wheels being formed with cipher-shaped apertures 138 at the zero position and masks 141 behind these apertures are rockable between blanking and indicating positions. When a numeral wheel is first moved from its zero position, a stud 97 on its carry gear 32 trips a latch 155 normally engaging under an arm 144 of its mask 141 and the mask is then rocked counterclockwise under spring action from blanking the indicating position. Each latch 155 has a lateral arm 161 underlying the next lower latch so that all lower masks 141 are released and moved to indicating position to distinguish as significant all zeros occurring in those orders. Released masks are restored to blanking position by means of a bail 177 upon operation of the zeroizing handle 71, a link 176 connecting the bail with the operating linkage of the frame 64. The machine also includes accumulator splitting means similar to that described in Specifications 729,820. and 744,974 Locking arms 315, Fig. 9, are engageable with the pinions 36 of the higher order accumulator wheels; these arms are released upon rocking a flatted control shaft 311 by depression of a control key 301, and are rocked by springs 321, to lock the higher order accumulator wheels during zeroizing, by pressure of the bail 177 on the tails of these springs. In order to render the action of significant zero indicating means appropriate to split condition of the accumulator, the lateral arm 161a, Fig. 9, of the latch 155 to the left of the split is cut off short so as not to trip the latch 155 to the right of the split. According to the invention a bridging lever 401 is introduced at the split and is effective to reestablish the latch interconnection when the accumulator is not conditioned for split operation. The bridging lever is rockable about the shaft 316 of the locking arms 315, has a leftwardly directed pin 405 overlying the arm 144 of the numeral wheel mask 141 to the left of the split and a finger 406 overlying the latch 155 to the right of the split. When this mask 141 is released and moves to indicating position by entry of an amount into its or a higher order, the bridging lever is permitted to move downwardly under spring action and trips the latch 155 to the right of the split so that all masks 141 to the right of the split also move to indicating position. Also rockable about the shaft 316 is a blocking pawl 402 for the bridging lever 401 having a tail 409 held down to the flatted control shaft 311 by a spring 413 and a stud 415 engaging a slot 416 in the bridging lever. When the shaft 311 is adjusted for split operation, the blocking pawl 402 rocks to position its stud 415 at the top of slot 416 and the stud holds the bridging lever against downward movement, so rendering it ineffective to interconnect the latches at the split. Means are also provided for maintaining the mask positions to the left of the split when the right-hand section of the split accumulator is zeroized. During zeroizing the masks 141 are, as previously explained, restored to blanking position by the bail 177 and held there by their latches 155. The means in question comprise pawls 424 adapted to retain tripped latches 155 in the left-hand section of the accumulator so that the associated masks return to indicating position upon return of the bail 177 after a zeroizing operation. The pawls 424 are straddled by a stirrup 419 linked with the control shaft 311. When the shaft 311 is adjusted for normal operation of the accumulator, the stirrup is rocked and blocks the pawls 424 against effective movement. The masks in the left-hand section of the accumulator are then latched in blanking position when restored during zeroizing with those in the right-hand section. Specifications 154,603, [Class 106 (i)], 344,868, 551,994 and 640,347 also are referred to.