Patent GB-226617-A (GB)
Abstract: 226,617. Thorburn, W., and Thorburn, W. Sept. 27, 1923. Adding and subtracting apparatus ; multiplying and dividing apparatus.-A stylus-operated machine for performing calculations according to the four rules in decimal or non-uniform systems comprises a stationary or a slightly slidable plate having slots representing the digits and their products by themselves or by monetary or other units, an escapement plate for laterally shifting a master-actuating wheel, and one or more slidably movable plates through all of which the stylus is adapted to pass and by its movement along the slot is adapted to operate the sliding plates whereby the movement is transmitted through the master wheel to two or more totalizer wheels of different denominations independently of one another. In the form shown in Figs. 1, 2, and 4 for calculatlions involving the British monetary units the fixed plate 11 is provided with a number of guiding lines 45 numbered from 1 to 9 with the lowermost line lettered " S " for subtraction, and these lines represent the multipliers and lead to members representing the multiplicands and to the slots where the stylus must enter. Beneath the fixed plate 11 is a slightly movable escapement plate 37 having equivalent slots but usually shorter in length so that the plate 37 is exposed at appropriate places, such as the ends or the bend, in the slots. This plate has depressions 21 in its lower surface engaging teeth 61 on a shaft 27, Fig. 5, and is under the control of springs 22, 52, 54, which tend to maintain it in a central position. On the shaft 27 is adapted to slide a master-wheel carriage 25 having a wide recess 62, Fig. 7, in the bottom thereof and provided at one end with a notched disc 66, and at the other end with a pivoted pawl 64, which parts co-operate with teeth 60 on the shaft 27 for laterally shifting the master-wheel 14 step-by-step, two steps being necessary to shift from one denomination to the next. The carriage 25 is urged to the right by a, spring drum 19 connected to the carriage 25 by a cord 17. The master-wheel 14, which slides on a square shaft 31, is adapted to engage successively with the numeral wheels 15, 38 of two totalizing-counters, and its actuating movement is effected by a movement of the shaft 31 through sprocket wheels 32, 42, 57, and a chain 53 attached at the ends to a movable plate 47. This plate 47 has horizontal slots or apertures for the reception of the stylus, and its movement is limited by the slot in the superposed plates 11, 37. The extent of insertion of the stylus is limited by a fixed supporting plate 48 arranged beneath the plate 47 as shown in Fig. 6. The master-wheel 14 has ten thin teeth and engages numerals wheels as shown in Fig. 3; the numeral wheels are separated by collars 16 to which are attached spring- aligning and overthrow-preventing members 29. The collars which are secured to the totalizing- counter spindles 19<A>, 41 and the members 29 serve as a means for zeroizing the numeral wheels when the spindles are rotated. Transfer is effected by teeth A<2> on the numeral wheels engaging pinions 7 as shown in Fig. 3, the movement of the pinions being transmitted to the next higher wheel by arms 7<D> on the pinions 7. To assist in the transfer operation, if consequent transfers occur, certain of the pinions 7 co-operate with light elastic discs 6, 36, frictionally mounted on spindles 5, 5<A> which are rotated by cross-belt drives from the shaft 31. Actuation is by the " so-called " simplified method, e.g. 4 x 7 is effected by adding " 3 " in the tens position and subtracting " 2 " in the units position, the slot for this problem being shown in Fig. 9. To indicate how the stylus is to be operated a system of dots or other signs are marked at the ends of the slots. Various modifications are described, (1) the moving plate may be an endles band, (2) the slots may be formed so as to effect the actuation of three denominational numeral wheels, (3) the master-wheel, sprocket, wheels, and chains may be dispensed with and the totalizer be moved transversely and be actuated by racks on the moving plate, (4) the numeral wheels of different denominations may be actuated simultaneously by providing a plurality of superposed moving plates. Specification 14645/96 is referred to.