Patent GB-346093-A (GB)
Abstract: 346,093. Calculating-machines. MATHYS, A. W., 52, Chancery Lane, London.- (Monroe Calculating Machine Co.; 555, Mitchell Street, Orange, New Jersey, U.S.A.) Feb. 11, 1930, No. 4646. [Class 106 (i).] In a calculating- machine having oneway active differential actuators and positive and negative operation control devices, a reversing device operated by the control devices is provided for the revolutions counter, manually operable setting means being provided in conjunction with the reversing dev i c e to cause the revolutions counter to register either in accordance with the sign of the operated control devices or opposite thereto. The invention is shown as applied to a machine of the type described in United States Specifications 1,011,617 and 1,566,961, in which subtraction is effected by complementary addition. A bolt 94, Fig. 6, locks one or other of two racks 89, 90 and so determines whether a number or its complement shall be registered in the totalizer. Depression of either the add key 113, Fig. 9, or the subtract key 114 rocks about its pivot 124 a lever 123 having a projection 128 engaging a shoulder 131 on a latch lever 130 pivoted at 132 to a release lever 133. The release lever is thus rocked to operate a spring- controlled clutch 66 of known type so constructed that when the release lever is restored to normal by release of the depressed key the machine is not stopped until the current rotation has been completed. The stems 115,116 of the keys 113, 114 also engage, by means of cams 142, 143, a pivoted lever 140 so arranged that only one key can be fully depressed at any time. Pivoted to the lever 140 is a link 145, Fig. 8, connected to a bell-crank lever 146 having a slotted end engaging a lever 149, Fig. 6, pivoted at 150 and engaging the bolt 94. A link 152 is operated by the lever 149 and, by means of a shaft 1530 and a lever 1531, slides a member 153, Fig. 9, along a square shaft 154. This member 153 is swung when the highest numeral wheel passes from nine to zero with the machine set for addition or fails to pass from nine to zero with the machine set for subtraction, the correct position of the member on the square shaft 154 being ensured by the lever 1531. To the square shaft 154 is also connected by links a bar 156 resting on a spring-controlled bell crank 158, the lower arm of which contacts with a lever 161 pivoted to the machine frame and contacting with the latch lever 130. Swinging of the member 153 lowers the bar 156, rocks the bell crank 158 and swings the lever 161 to rock the latch lever 130 until the shoulder 131 thereon escapes from the projection 128, the release lever 133 then being pulled by a spring 134 to stop the machine. The revolutions counter is operated by a pinion 169 on a sliding shaft 168 which is driven by a wheel 78 through one or other of two wheels 164, 165 according as the machine is set for addition or subtraction. The sliding of the shaft 168 is effected from the key-actuated lever 140 by means of a pivoted lever 144 acting, through means described below, on a disc fixed to the shaft. It is necessary, when dividing by the " subtract-shift-add-shift" method, to reverse the action of the revolutions counter gear-changing lever 144. The end 200. of the lever 144, Fig. 10, projects between two pins 201, 202 fixed to a plate 203 pivoted at 204 to a lever 205 pivoted at 206 and operated by an external knob 207. The pins 201, 202 move the disc secured to the gear shaft. For division, the knob 207 is moved to the left, thereby moving the pins 201, 202 out of the range of the disc and other pins 211, 212 also secured to the plate 203 into the range thereof. The effect of the lever 144 is thus reversed. The knob 207 can be operated only in the stationary position of the machine, a projection 214 secured to the lever 205 resting behind a disc 215 having only one slot 216 therein.