Patent GB-191021704-A (GB)
Title: Improvements in Calculating Machines.
Inventor: AUSTIN SYDNEY BERTRAND
Filed: 1910-09-19
Granted: 1911-09-19
Abstract: 21,704. Austin, S. B. Sept. 19. Adding and subtracting apparatus with operating-means. -Relates to single - bank machines for adding, subtracting, and multiplying by repeated addition, of the kind in which transmitting-elements successively set are moved step-by-step transversely, the apparatus being suitable for combination with typewriter. Differential mechanism; selecting denomination. - The hubs of the keys mounted loose on a shaft 3 have pins to engage spaced pins on the shaft so as to rock it differentially and with it a selector 6 in the form of a toothed cylinder. At the end of its stroke the key rocks a spacing- yoke 21 linked to the frame 26 carrying the pawls 12, 13 cooperating with a spacing rack 11. The rack 11 has uprights between which are placed, loose on a shaft 8, transmitting gear segments 6<1> so that at each movement of the yoke 21 another segment 6' engages from right to left with the selector in its momentarily set position, the selector then dropping back to normal and carrying each newly-set transmitting segment with it. After setting an item, the main lever is rocked forward, and by means of gearing and a spring clutch 33 rocks a cam shaft 35, on which first a cam 36 through a lever 38 pivoted at 39 and a link 40 rocks the selector, thus bringing the transmitting segments 6<1> into gear to actuate the totalizer 27. At the limit of movement of the selector, a cam 42 through a lever 44 and link 45 and bent lever 46 moves the spacing-carriage laterally, so as to bring the transmitting segments into the spaces between the totalizer gears, whereupon the cam 36 engaging a second roll 47 on the lever 38 lowers the selector, which is then returned to initial lateral position. This is effected by means of a lever 17 always urged towards the left by a spring 20, but which is linked to a lever 49, Fig. 7, having a second arm with a roll 48 to engage the flat side of a cam 48<a> feathered on the shaft 35. Normally a roll 64 is held fast so that the cam 48<a> bearing against it throws over the lever 49 as described. For subtraction a key 58 is pushed in, which brings into action a cam 42<a> instead of 42 so that the transmitters 6' only act on the reverse stroke. To ensure restoration to exact initial position of the transmitters, a cam 52 is provided to rock a yoke 57 so as to bring the edge of all the transmitters back to engagement with a zero position bar 51, both extending only over the initial position of the segments. Multiplying and dividing by repetition.-For multiplication, a key 62 is thrust in order to remove the normally-fixed roll 64, so that the levers 49 and 17 are not thrown over to the right, thus allowing the same item to be repeatedly added on each operation of the handle. By inserting both keys 58 and 62 repeated subtractions may be made. Error keys.-To correct a wrong setting, a special key is thrust in so as to rock the lever 46 and bring the transmitters into the interspaces on both up and down strokes the whole being then returned to initial position as before. Attachments and connexions to typewriters.- A typewriter may be fitted with the machine, as shown in Fig. 3, the adding-keys, when depressed, tensioning springs 69 attached to links 67<11>, which are released from catches 68' at the end of the key stroke so as to operate the typewriter keys 65<1>, the connecting-links being slotted so as to permit operation of the latter without adding. The cam shaft and keyboard of the adding-machine are extended, as shown in Fig. 1, when combined with the typewriter.