Patent GB-756772-A (GB)
Title: Improvements in or relating to calculating machines, accounting machines and the like
IPC: G06C7/10
Filed: 1954-04-09
Abstract: 756,772. Calculating-apparatus. AKTIEBOLAGET ADDO. April 9, 1954 [June 12, 1953], No. 10542/54. Class 106 (1). In a " ten-key " machine having an abutment stop for controlling step-shifting of a settable pin carriage, and wherein the stop is displaceable in the step-shift direction at the commencement of each machine cycle in order that the carriage shall by-pass the lowermost orders of the differential actuators, the stop is positively coupled to the carriage when it is so displaced in order to compel the carriage to move with the stop. The type of machine concerned is one in which the lowermost orders of the actuators, totalizer and printing mechanism are constructed for non-decimal amounts and these orders must be by-passed by the pin carriage when decimal amounts are being entered. The mechanism shown is for sterling and decimal amounts; the pin carriage 1 has twleve pins 2, 3 in each column, the lowermost (pence) actuator 6 is connected to its toothed segment 7 at a point 12 more distant from the centre 8 than are the connections 14a of the remaining actuators, and the three lowermost type bars 11 and totalizer orders are appropriately modified for pence and shillings. Step-shift of the carriage is controlled by successive disengagement of the foremost pins 3 from abutting contact with an upturned stop flange 4 of a normally stationary stop lever 5. This lever is mounted on a fixed stud 16 by means of a slot 17, and is provided with a roller 18 and a cam slot 22 engaging, respectively, a cam 19 and a pin 21 on the cam. A longitudinal bar 25 is connected to a camslotted driving lever 27, by which it is moved rearwardly and then forwardly at each oscillation of the main shaft 33. In decimal calculations a key 44 is depressed which lowers a lever 42 pivoted at 43, a depending arm 41 of the lever, through a link 40 and lever 37, rocking the bar 25 inwardly to engage a slot 24 with a stud 23 on the cam 19. As a consequence the cam 19 is rocked clockwise by the bar 25 at the commencement of each machine operation and the pin 21 displaces the stop lever 5 to the left (Fig. 3) so that the set orders of the pin carriage move clear of the three sterling actuators 6 which are now blocked by means of a projection 45 on the lever 42. According to the invention, the stop lever 5 is formed with a nose 14 and is rocked by the cam 19 prior to displacement by the pin 21 so as to engage the nose between two pins 3 of the carriage. The carriage is consequently positively coupled to the lever 5 and accompanies the lever in its rapid leftward movement. The mechanism shown has a total of ten numerical orders, seven of which are available for decimal calculations. Depression of the decimal key 44 is prevented, when more than seven orders of the pin carriage have been set, by the engagement of a flange 50 on the carriage under a pawl 48 on the lever 42. With the key 44 already depressed the pawl 49 blocks further step movement of the carriage after seven digits have been set; the pawl is, however, rocked clear against the action of a spring 51 during the three-step displacement by the stop lever 5.