Patent GB-1308881-A (GB)
Title: Calculating machine
IPC: G06C7/10
Filed: 1971-01-05
Abstract: 1308881 Calculating machines; transfer mechanisms CITIZEN WATCH CO Ltd 5 Jan 1971 [6 July 1970] 462/71 Heading G4B In a ten-key calculating machine, the conventional keyboard has additionally a fraction key, the arrangement being such that when a number not including the fraction is entered a zero is automatically introduced as the lowest denomination of the number on actuation of a transfer function key, whereas when the number set terminates in the fraction the zero introducing mechanism is locked. Such an arrangement prevents denominational errors. In the embodiment described, the fraction key 3, Fig. 2, is "¢" and by means of a setting lever 7a sets a pin "5" in pin carriage 16. Furthermore, key lever 22 of key 3 has extension 22a which shifts a locking lever 23 to lock the zero introducing mechanism (see below). Each function key 24, Fig. 4, coacts with a slide 27 such that on depression of the key, an extension 27a of the slide displaces a lever 33 to actuate the zero introducing mechanism. This mechanism essentially comprises a zero-pin setting lever 45, Fig. 6, which as shown, has been released on displacement of lever 33 to move through spring 49 to set a zero-pin by contact with the associated zero-pin extension 20a, see also Fig. 2. The operation of lever 45 is brought about by successively, clockwise rotation of lever 33 about pin 34, clockwise rotation of lever 38 about pin 41, lever 38 being connected to lever 33 by claw lever 35, disengagement of lug 38b on lever 38 from a step 32a on the machine frame, and combined movement towards pin carriage 16 of lever 38 whose lug 38a moves out of notch 35b, lever 40, connected to lever 38 by pin 41, and zero-pin setting lever 45 connected to lever 40 by pin 47, all through the action of spring 49. Setting of a zero-pin by lever 45 also allows the pin carriage to escape since the set pin clears a column shifting lever 14, Fig. 2. After entry of the number into store, the pin carriage is cleared by a plate (57), Fig. 8 (not shown), and a return lever 53, Fig. 6, connected thereto, is moved away from the pin carriage to rotate lever 40 clockwise via lug 53b and therefore move zero-pin setting lever 45 and lever 38 away from the pin carriage. Lug 38b is reengaged with step 32a and after return of pin carriage 16 to its initial position, slide 27, Fig. 4, returns to its home position thereby rotating lever 33 to bring notch 35b of claw lever 35 once more into engagement with lug 38a on lever 38, see Fig. 5 (not reproduced). The zero introducing mechanism is now in its initial position. When the fraction key is depressed, locking lever 23, Fig. 6, is rotated anticlockwise about pin 46. When subsequently a function key is depressed, the zero introducing mechanism is operated as before, but zero-pin setting lever 45 is halted by engagement of pin 47 thereon with end 23a of lever 23, see also Fig. 7 (not reproduced). The normal escapement mechanism of the machine occurs in two stages. Firstly a slide 11, Fig. 2, is moved towards pin carriage 16 on setting movement of any lever 7 and rotates clockwise column shifting lever 14. This frees the carriage which moves until a pin 21 abuts projection 11b of slide 11. When lever 7 returns on release of the associated key, slide 11 returns also, pin 21 is released, and the carriage moves further until the next zero-pin 20 engages column shifting lever 14 now in its original position.