Patent GB-779039-A (GB)
Title: A full keyboard listing adding machine
IPC: G06C7/06
Filed: 1955-08-26
Abstract: 779,039. Calculating-apparatus. FERRARO, R. C. Aug. 26, 1955 [Aug. 31, 1954], No. 24609/55. Class 106 (1). In a full-keyboard adding-listing machine having opposed add-subtract differential racks extending over and under a set of totalizer pinions, the racks are slidably supported by transverse rods of a frame which is lowered or raised to condition the machine for addition or subtraction. Amount differential. In the embodiment described, each column of amount keys 6, Fig. 3, controls rearward movement of a differential stop bar 66, the stems of the keys being staggered for co-operation with stop studs 73 projecting from either side of the stop bar. A zero stop pawl 57 normally prevents movement of the bar, but is released by the usual key latching plate 56 upon depression of any key. Each stop bar 66 is connected, by means of pinions 68 on an individual shaft 169, with a companion secondary differential bar 76, Fig. 8, the rear end of which has an upstanding arm 95 supportirig a twin totalizer actuating rack 93 by means of a pin-and-slot connection, so that either an upper add section or a lower subtract section can be engaged with the corresponding totalizer pinion 97. The bars 76 are moved rearwardly by springs 82 upon release by pawls 85 at the end of the downward stroke of the hand-crank 23, the stop bars 66 differentially limiting the rearward movement. A restoring rod 127 returns the bars 76 and 66 as the hand-crank returns upwardly. Operating mechanism. The shaft 24, Fig. 20, of the operating hand-crank 23 is connected through an arm 203 and a yielding spring 205 to a toothed sector 27 adapted, through pinions on a shaft 220, to drive a pair of operating bars 222 rearwardly upon downward movement of the hand-crank. Springs 226 effect return movement and a full-stroke pawl 209 controlled by a latch 212 engages a ratchet sector 208 on shaft 24 to ensure a full downward stroke. The restoring rod 127 is moved rearwardly under spring action when released as the operating bars 222 commence rearward movement and is picked up and returned forwardly by latch levers (not shown) on the bars as the bars are returned by their springs 226. Other mechanisms of the machine are operated by the operating bars 222, or by cams on the shaft 220 or hand-crank shaft 24. Function control differential; addition and subtraction. The machine has a single column of function control keys and, associated therewith, a differential stop bar 144, Fig. 18, connected by means of pinions on a shaft 157 with a secondary differential bar 159 similar to the amount of differential mechanism. The twin totalizer actuating racks 93, Fig. 8, are carried between upper and lower pairs of grooved rods 197 of a supporting frame 196 whose vertical movement is controlled by means of a pair of interconnected slides 171, Figs. 18 and 49, formed with cam surfaces engaged by rollers 199 on the frame 196. The slides are adjusted rearwardly with the differential bar 159, a stud 168 on an upstanding arm 167 at the rear of the bar 159 being normally engaged by a stud 183 on an arm 182 pivoted to the rear of one of the slides 171. A spring 165 is adapted to move the bars 144 and 159 rearwardly as the restoring bar 127 moves rearwardly during the downward stroke of the hand-operating lever. The machine is normally conditioned for addition and a pivoted stop 141, similar to a zero stop, arrests the stop bar 144 and slides 173 after a movement sufficient to bring lower surfaces A on the slides into engagement with the rollers 199 of the frame 196. This lowers the frame and brings the upper or add sections of the totalizer actuating racks 93 into engagement with the totalizer pinions 97. Thereafter, the pawls 85 are operated to release the amount differential bars 76 to their springs 82 so that the set amount is entered additively into the totalizer. A stud (not shown) on the operating bar 222 engages and lifts a support 190, Fig. 18, for the arm 182 at the end of the downward stroke of the hand-crank; this disconnects the slides 171 from the differential bar 159, so that the slides are immediately returned by springs 192 and the actuating racks 93 disengaged from the totalizer pinions before the hand-crank commences its return movement. Depression of the subtract key results in further movement of the slides 173 sufficient to bring upper surfaces S into engagement with the rollers 199 of the frame 196. This raises the frame so that the lower or subtract sections of the totalizer actuating racks 93 are engaged with the totalizer pinions 97. Tens transfer mechanism. Each totalizer actuating rack supporting arm 95, Fig. 8, is slidable on its differential bar 76 for an additional step of rearward movement under the action of a spring 92, this movement being normally resisted by a latch lever 110 carried by the bar 76. At transfer, a tooth on a disc fast with the lower order totalizer wheel trips a second latch lever 106 which releases a lever 108 to the action of a spring 118. A lower arm of the lever 108 thereupon depresses the latch lever 110 of the higher order, so that the arm 95 of the higher order moves rearwardly on its bar 76 to enter an additional " 1 '' in that order. A rod 126 finally restores released levers 108 to reset the mechanism. Key restoring mechanism; repeat operation. During downward movement of the operating hand-crank, a cam 353, Fig. 37, on its shaft 24 idly rocks a by-pass pawl 345 on a lever 338. On the upstroke of the hand-crank, the cam 353 rocks the lever 338 which rocks a bell-crank 330 counterclockwise, a rod 335 on the bell-crank displacing the key-latching plates 56 to release depressed keys. A correction key 13 is adapted to rock the bell-crank 330 directly to release erroneously depressed keys. A repeat key 12, when depressed, rocks a fulcrum abutment clear of the fulcrum stud 352 of the lever 338; the cam 353 is then unable to operate the lever to clear the keyboard so that the key setting remains for repeat entry as long as the repeat key 12 remains depressed. The key 12 is latched down by rocking it forwardly to engage a notch 356 in its stem under the key plate. Printing mechanism. The secondary differential bars 76, Fig. 42, are each provided at the rear end with a second upstanding arm 367 spaced laterally from the arm 95 (see above) supporting the totalizer actuating rack 93. This arm 95 has rack teeth 3671 for adjusting a corresponding type wheel 374. The arm 367 has limited rearward movement on its bar 76, under the action of a spring 371, for the purpose of advancing the wheel 374 from the blank to zero position. A pawl 381 normally prevents this movement, a nose on the pawl engaging a notch 380 in the differential bar 76. Upon movement of the bar 76 rearwardly, the pawl 381 is tripped and the arm 367 released for rearward movement with the bar to the set digit position. The pawls are provided with overlapping parts so that all pawls below the highest set order are tripped and unset ones of these orders are adjusted to print zeros. The platen 18 is advanced towards the type wheels to effect the impression by means of a cam 389 on the handcrank shaft 24, the cam rocking pivoted levers 391 supporting the platen.