Patent GB-1356964-A (GB)
Title: Calculating machine keyboards
IPC: G06C7/06
Filed: 1971-05-19
Abstract: 1356964 Manually or electrically operable business machines SVENSKA DATAREGISTER AB 19 May 1971 [3 July 1970] 15864/71 Headings G4T and G4B [Also in Division B6] Relates to a calculator or cash register, of the type having for each order a row of ten digit entry keys T0-T9, with associated stems 34, and wherein entry of a number may be effected either by manually depressing selected keys, or by selectively energizing electrical devices which act on the respective key stems. Associated with each key is a solenoid S0-S9, energization of which e.g. by signals received from a central station and processed to energize the correct solenoid by a circuit, Fig. 6 (not shown), pivots a plate 32 about a line through lugs 32a, 32b into a set position wherein it abuts end 30a of the solenoid core 30 (Fig. 3) and a third lug 32c is brought into vertical correspondence with a step 34b (also Fig. 4, not shown) of the key stem 34. Subsequent clockwise rotation of a cam-shaft 40 allows a spring 50 to move a slide 36 to the right. Slide 36 is apertured at 36a (Fig. 3) to receive the lugs 32a, so that rightward movement of the slide pivots the plates 32 about lugs 32b, whereupon the set lug 32c engages step 34b to depress the key stem. The lugs 32c of the other nine un-set plates 32 of each order are vertically aligned with steps 34a, through which the lugs 32c can depress stems 34 through half the distance achieved by a set lug 32c engaging step 34b. Depression through such a half distance is, however, prevented in this case by the fully depressed set key stem entering crowding lock mechanism 64. Continued rotation of cam-shaft 40 resets the slide 36, through cam follower 46, and resets the set plate 32, through a yoke 56, pivotable about a shaft 58 (by means of cam follower 62) and formed with lugs 56a, one of which engages a lug 32d of the set plate 32 to restore same. Each plate 32 in its unset position abuts end 30b of the adjacent solenoid core (Fig. 3). Either plates 32 or cores 30 are permanently magnetic for holding any plate 32 in its set position without continuation of the solenoid excitation current. Crowding lock mechanism 64 prevents more than one key stem extension 54 in any one order from being depressed through the normal working stroke. If two or more solenoids in one order have, in error, been energized, then the mechanism 64 will prevent further depression of the corresponding extensions 54 when the latter have moved through the half distance referred to above. Also, if in error no solenoid in a particular order is energized, then all the key stems will be depressed through the half distance. Errors preventing.-If, in a particular order, either no solenoids or more than one solenoid has been energized, then, as described above, a key stem extension 54 will be depressed through half its normal stroke and this aligns a lug 54a with a lug 68a to prevent shifting to the right of a machine operation start slide 68. Differential mechanism and indicators, Fig. 5 (not shown), includes for each order two parallel racks which are moved in opposite directions through the same distance by a cam-operated linkage until a projection on one rack engages a depressed key stem extension 54. A totalizer is engageable with one of the racks. A third rack located between the first two permanently engages an indicator wheel 90. The three racks are formed with co-operating projections arranged for setting the third, indicator rack during the working stroke of the first two racks and for imparting no movement to the indicator rack during the return stroke of the first two racks.  Generating an electrical output representative of either the amount held in the totalizer or an amount manually entered at the keyboard.-Yokes 70, 72 (Fig. 2) are rotatable about and slidable along shaft 58. Their longitudinal position is adjusted by a rack 74, with which they co-operate through lugs 70f, 72f. Rack 74 co-operates with the respective order indicator wheel 90 so that the position of yokes 70, 72 is representative of the number stored in wheel 90, a tooth 70a- 70e, 72a-72e being positioned exactly in front of lug 32d of the plate 32 corresponding to this number. On rotating a cam-shaft 86, either yoke 70 or yoke 72 is pivoted, by a lug 82a or 82b cooperating with an extension 70g or 72g. This pivoting acts through the operative tooth (in the position shown, tooth 70a) and lug 32d to rock the corresponding plate 32 into contact with the solenoid core. This changes the inductance of the respective solenoid and this change is sensed by a circuit, Fig. 6 (not shown), to generate an electrical output signal representative of the total stored in the machine. Alternatively, the changes of inductance may be caused by shims 170 of ferromagnetic material carried by the key stems and contacting the solenoid cores when the corresponding keys are depressed; in this case the electrical output signal generated by the Fig. 6 circuit represents a number manually entered at the keyboard.