Patent GB-684405-A (GB)
Abstract: 684,405. Calculating - apparatus. BRUNSVIGA - MASCHINENWERKE GRIMME, NATALIS & CO. AKT.-GES. Oct. 26, 1949 [Jan. 20, 1949], No. 27520/49. Class 106 (i). A motor driven calculating - machine having a totalizer carried on a carriage slidable under spring tension is so arranged that when the completion of one stage of a division operation is indicated by a zero-pass condition, the necessary correcting revolutions and carriage shift are controlled by a plurality of superfluous minusrevolutions which are followed by a number of correcting revolutions equal to the plurality of superfluous minus - revolutions. In the embodiment disclosed, a second superfluous minus-revolution takes place in addition to a first one causing the zero-pass condition, the second superfluous minus revolution initiating a first plus-revolution and the first plus-revolution initiating a second plus-revolution causing the totalizer carriage to move to the left for the next stage of the division. In Fig. 1, an impulse is applied to a bar 1, during the first superfluous minus-revolution of the driving shaft 3, by a tens transfer member in the highest digit place of the totalizer. The bar 1, mounted on brackets 2 pivoted at 4, is moved clockwise by the impulse and, through a link 5, presses a catch 6 away from a bell-crank lever 7 which is then moved clockwise by a spring 8. The spring 8 also acts on the brackets 2 to bias the bar 1 back to its original position after receiving an impulse. The lever 7 is pivoted at 10 on a lever 11 pivoted at 12. A forked end of the lever 11 is engaged by an eccentric 13 on the driving shaft 3 so that the lever 11 is rocked on each revolution of the shaft 3. During the first half of the second superfluous minus-revolution, the rocking movement of the lever 11 brings a projection 14 of the lever 7, freed from its catch 6, behind a lug 15 of a lever 16 pivoted on the shaft 4. A second bell-crank lever 17, pivoted at 24 on the lever 11, engages a recess in the lever 16 as shown in Fig. 1b. The movement of the projection 14 moves the lever 16 against spring means 18 away from the lever 17 which is then moved anti-clockwise by a spring 19. During the second half of the second superfluous minus-revolution, the rocking movement of the lever 17 is such that a projection 25 on the lever 17 moves through the positions 251, 2511 and 25, respectively, and thus rotates a control wheel 22 by one tooth from the position shown. This rotation causes a cam 29, Figs. 2 and 2a, on the shaft 28 of the control wheel 22, to depress a plus-key 30. The depressed plus-key 30 reverses the drive to the machine, causing the shaft 3 to rotate in an adding direction and rock the lever 17 in a manner advancing the wheel 22 by a further tooth. The cam 29, Fig. 2a, is such that the plus-key 30 is held in position to cause a second revolution of the shaft 3 in the adding direction and the advancement of the wheel 22 by a further tooth. Thereupon the cam 29 is moved away from the plus-key 30 to stop the adding revolution of the shaft 3 and, at the same time a cam 32 on the shaft 28 depresses and releases a key 37. The key 37 is connected to a shaft 35 having angularly-displaced teeth 40, 41 on a member 38 co-operating with teeth 39 on the slidable totalizer carriage 31. Downward movement of the key 37 brings the tooth 40 out of, and the tooth 41 into, engagement with the teeth 39, thereby allowing the totalizer carriage 31 to move half a step to the left under the action of a spring 42. Upward movement of the key 37 allows, in a similar manner, the totalizer carriage 31 to move a further half-step to the left. For proceeding with the division, the subtraction of a divisor must be continued after the totalizer carriage 31 has been shifted to the left. This is effected by depressing a minus key 62 either manually or, if desired, automatically by the movement of the totalizer carriage using the apparatus in Fig. 5. In Fig. 5, one arm of a bell-crank-shaped latch 64 is spring-biased against the left-hand end of the shaft 35, the other arm of the latch 64 engaging a recess at the end of one arm 66 of a threearmed lever 67. The right-hand arm 68 of the lever 67 is spring-biased against a projection of the minus-key lever 62. The left-hand arm 70 bears against an eccentric 71 which may be on a shaft 72 operationally inter-connected with the shaft 3 of the calculating mechanism. When the totalizer carriage 31 is moved to the left, it gives an impulse to the member 38 and hence the rod 35 against the action of a spring 36. The impulse to the left by the shaft 35 rotates the lever 64 and thereby releases the lever 67 which under the force of a spring 69, acting as a power accumulator, depresses the minus-key 62 to cause minus-revolution of the shaft 3 to be initiated. The lever 67 is subsequently reset to its latched position by the operation of the eccentric 71 acting on the arm 70. The members in Fig. 1 are also returned to the positions shown. The minus-key 62 and the plus-key 30 are interlocked so that the minus-key 62 is retained in its depressed position until it is released by the depression of the plus-key 30.