Patent GB-902247-A (GB)
Abstract: 902,247. Calculating-machines. COMPTOMETER CORPORATION. March 24, 1959 [May 1, 1958], No. 10124/59. Class 106 (1). A single-bank keyboard printing adding machine with a pin-carriage is modified for making calculations involving either decimal or sterling amounts and has a " 00.0 " key 42 which causes the pin-carriage to jump the last three (sterling) denominational positions and the three lowest order actuators to be arrested in zero position. A whole number " WN " key 73 is also provided. This key is depressed before the setting of a decimal amount and conditions the mechanism for causing the pincarriage to jump the lowest order positions, but the jump only occurs on depression of any one of the starting control keys. The lowest order actuators are again blocked and in this case, the corresponding printing hammers are held inoperative. The " 00.0 " key.-Depression of this key 42 rocks a latch 52, Fig. 8, to allow a longitudinal shaft 47 to be rocked by a spring. An arm 51 on this shaft disengages the normal escapement mechanism 22, 23 for the pin-carriage and engages a pawl, Fig. 7 (not shown), with a rack 43, Fig. 4, urged by a spring 45 to follow the pincarriage 12 and slidably mounted on studs 44 in an extension 35 of it. The pin-carriage is then able to move under the action of its spring 25 through three columns until the left stud 44 engages the end of the slot in the rack 43. The key 42 also acts on a slide 68 to release a slide 59 having a flanged portion 61 which is thus moved behind projections of the three lowest order actuators to arrest them in zero position. The " WN " key,-On depression of this key 73, which is self-latching in its depressed position, the slide 68, Fig. 4, is again actuated to release the zero stop slide 59 for the lowest orders for movement to effective position. The key 73 also acts through a lever 78, Fig. 3, and link 81 to rock a bail 83 over tails of the three printing hammers of the sterling denominations to prevent the printing of the zeros. In order to condition, for subsequent operation, the mechanism, operated as described above by rocking of the latch 52, Fig. 8, which causes the pin-carriage to jump the three lowermost denominational positions, the lever 78 rocked by the key 73 acts on a stud 85 in a lever 86 to cam the end of the latter sideways and position it over the latch 52. The other end of the lever 86 engages a ratchet-wheel 87 on a transverse shaft 94 carrying a second ratchet-wheel which is advanced one step each time any one of the starting control keys is depressed. Thus, when such a key is operated, the lever 86 is rocked and, if the key 73 is in depressed position, the latch 52 will also be rocked to cause the pin-carriage to be advanced beyond the sterling denominations. Indicating position of pin-carriage. The extension 35 of the carriage carries fingers 96 which co-operate with a fixed scale 36. The two fingers are spaced by the width of three columns of the pin-carriage and are for use in decimal and sterling calculations respectively. Pence order.-Each column of the pin-carriage has eleven pins to enable the pence rack 15, Fig. 5, to be arrested after from one to eleven steps of movement. The rack 15 meshes with a pinion 38 which drives a pence type wheel 14a and which is fast with a smaller pinion 41 in turn meshing with an extra rack 15a which actuates the pence totalizer wheel. The arrangement is such that twelve steps of the rack 15a correspond to ten steps of the other racks.