Patent GB-334045-A (GB)
Abstract: 334,045. Mathys, A. W., (Monroe Calculating Machine Co.). Aug. 13, 1929. Multiplying and dividing apparatus. - In a machine provided with means for driving the counters automatically in either direction for performing division, a control key is arranged to initiate additive operation and to set the automatic reversing devices in operative condition. The arrangements are such that division and multiplication of a number may proceed simultaneously, thus enabling the evaluation of such a expressions as - x c to be performed at one and b the same time. The invention is illustrated as applied to the Monroe machine described in Specifications 27231/12 and 216,174. In addition to the usual banks of multiplicand keys 18, the keyboard has a special bank of keys 430, 451 for setting up the value of the divisor and initiating the operation of the machine. The key 430 sets the corresponding selector bail 19, Fig. 4, to enter unity while the other keys, denoting, for example, percentages, act through individual frames 454, Fig. 5, provided with lugs 455, 456, to set the selector bails of the four highest denominations according to the reciprocal of the value of the percentage. When the key 430 (or one of the other keys 451) is depressed a bell-crank 437, Fig. 3, is rocked to shift a slide 438 to the left and so, through a lug 439 and latch lever 303 to remove a lock lever 200 from obstructing the rock-arm 22 linked at 21 as usual to a crank on selector gear shaft 4. The key 430 also shifts a slide 433, Fig. 4, to the left where it is held in position by a latch 435, Fig. 3, freed by the movement of lock-lever 200. The movement of the slide 438 also effects through a pin 441 the rocking of the clutch yoke 111 clockwise to start the machine in additive operation. The automatic control of the machine is exercised through the division lever 201 normally rocked by hand to throw the machine into subtractive condition, the lever acting upon the clutch yoke 111 through the medium of a pawl 319 and a nose 208 of the yoke. When the machine is to operate automatically, in accordance with the present invention, this pawl is disabled by the leftward shifting of the slide 438, a lug 442 of which disables a latch 443 from holding the pawl rigid. The pawl is thus free to rotate, under spring action and moves out of the path through nose 208. Pivoted slidably at 444 is a plate 462 having a lug 447 adapted to be engaged by a pin 50 on link 21 so as, in the operation of the machine, to be shifted to the right and through a nose 445 meeting the pivot pin of pawl 319, to rock the division lever 201 to the right. This through a pin 211 will shift a sliding tooth 209 mounted on the yoke 111 also to the right into a protruding position in which it is locked by a latch 213. As described in Specification 216,174, when the highest numeral wheel of the totalizer passes through zero, the stop-arm 24 is carried to the right by the rock-arm 22 and engages a fixed stop, a pin 145 on an extension of the stop-arm camming the yoke 111 to neutral position. The stop-arm rebounds from the stop and a tooth 220 of link 21 thereupon engages the protruding sliding tooth 209 and so causes the yoke, 111 to swing into subtractive position to reverse, the operation of the machine. When the division lever 201 is rocked, as above described, a clutch hub on the carriage-shift shaft is also slid into operative position so that when the stop-arm 24 is carried against its stop, due to the transitional action, and pin 50 engages a push-rod mounted. on arm 24, this rod swings a bell-crank lever and rotates the shaft to shift the carriage. After a subtractive series of operations, pin 50 ascends and the rod does not operate the bell-crank lever so that no carriage shift occurs. Thus the machine will operate forwardly and backwardly alternately, the carriage shifting automatically at the end of the forward operations only until the division lever is returned to inactive, position, as by the carriage reaching the end of its travel and the corrective. additive operative having been performed. Under these conditions a pin 219, Fig. 3, on the lever trips the latch 213, whereupon the tooth 209 is withdrawn and the clutch yoke is left in neutral position. The pawl 319 will also be restored by meeting an extension 450 of the slide bar 438 and will be again held by latch 443. Latch lever 303 and locking-lever 200 are restored by upward movement of the pin 145 rocking a plate, pivoted on the latch-lever 303 and through co-operation of a pin on the now-withdrawn tooth 209 shifting the latch-lever to release the locking-lever, this in turn liberating the slide 433. In the performance of a combined multiplication and division, one factor is entered in the totalizer in the form of its complement and the other factor is then set up on the keys 18. Upon depression of the divisor key 430 or 451 the machine proceeds to operate and at the conclusion the result appears in the totalizer and the first factor in the revolutions-counter.