Patent GB-166486-A (GB)
Abstract: 166,486. Rauchwetter, F. July 7, 1914. Multiplying and dividing apparatus.-In machines for performing calculations according to the four rules means are provided for effecting division automatically. According to the invention, the dividend is set up on the totalizing-counter and the divisor on the multiplicand keyboard, then the division key is depressed and the main handle operated, whereupon subtraction is effected until excess registration has been made which causes the highest numeral-wheel to pass from " 0 " to " 9 " and thereby automatically releases the division key and depresses a correction key so as to. change the machine from subtraction or division to addition or multiplication and to add the divisor once and thereupon effect a total shift of the totalizing-counter carriage. When performing multiplication, a bar 100, Fig. 2, adapted to be reciprocated by a bar 110 actuated from the main operating-mechanism, is normally free to pass between the lateral projections 103, 104 of bell-crank levers 102, 101 connected to the correction key 102<1> and division key 101<1> respectively. In division, the key 101<1> is depressed, and after excess registration a 'pin 92 on the highest numeral wheel rocks a bell-crank lever 93 to ring a bell 95 and through levers 98, 99 to actuate the bar 100, and thus cause the spring 106 on the lever 101 to engage the surface 109 of the bar 100 and so raise it that on the subsequent rearward movement of the bar 110 the projecting end 107 engages the projection 103 and thus rocks the lever 102 to lower the correction key and release the division key, the release being effected as described in Specification 166,488. The stem of the correction key in the depressed position acts as a stop for a lever 119 connected to a bell crank lever 116, the other arm of which is connected to a lever 117 operated by a pin 114 on a disc 115 on the main operating shaft and associated with a lever 118 adapted to operate the lateral shift mechanism of the totalizing-counter carriage as described in Specification 16188/14. On the succeeding operation of the machine the pin 92 again rocks the bell crank lever 93 so as to push the rod 100 to the right as shown in Fig. 4, and by means of the spring 105 on the lever 102 the projecting end 108 is lowered so as to engage behind the projection 104 of the lever 101 so that on the next succeeding operation the division key is depressed and the correction key released. In a modification the process of division is expedited by subtracting the divisor twice at each operation of the machine while the correction operation is made once or twice, the number depending on whether or not the highest numeral wheels passes from 9 to 0. As shown in Figs. 5 and 9, the division key 101<1> is provided with a notch engaging a pin 120 on a notched bar 121 which normally allows a projection 122 on a bar 123 controlled by the multiplier keys, as described in Specification 166,489, to pass freely, but on the key 101<1> being depressed the bar 121 is moved so as to arrest the bar 123 when the machine is operated; the movement of the bar 123 corresponding to the multiplier " 2 " sets the product plate " 2 " so that the divisor is multiplied by " 2 " and subtracted from the dividend at each operation. On the machine being set for correction as above described a pin 124 on the bell crank lever 102 rocks a lever 125 in order to bring its notched end into the path of a bar 128 connected to the lever 116 associated with the lateral shift mechanism of the totalizer carriage. The lever 125 is rocked to bring the shorter notch 126 opposite the bar 128 when the highest numeral wheel passes from 9 to 0 by means of a bevelled surface 129 on the bar 100 engaging a pin 130 on the said lever; if the deeper notch 127 is presented to the bar 128 the latter can move freely, and this will not affect the position of the carriage.