Patent GB-205870-A (GB)
Title: Improvements in or relating to calculating machines
IPC: G06C25/00
Filed: 1922-07-24
Abstract: 205,870. Landsiedel, H. July 24, 1922. Type-wheel actions; accenting and like arrangements; hammer-impression mechanism.- In a recording and adding machine in which typecarriers set by the differential mechanism are forcibly advanced against the platen by spring- actuated hammers, the hammer latches are controlled by a cross-bar or bail pivoted at one end to a fixed support and oscillatable at its free end by the main operating-shaft. The bar is movable in one direction by yielding means, and keyoperated mechanism is provided for operating a device to prevent movement of the cross-bar and thus prevent the release of the hammers. The machine is particularly adapted for effecting subtraction, and for correcting for the introduction of an erroneous item by adding a number which is the complement less one of the item and completing the movement by the automatic addition of unity to the totalizer pinion, in the units denomination. During this subtraction operation, the releasing-device for the impression-hammers, the means preventing the printing of zeros to the left of the highest significant figure in the item, and the line-spacing mechanism are rendered inoperative, and at the end of the operation the parts are restored to the position for performing addition. The invention is shown applied to a machine of the type described in Specification 854/04. To correct an error and remove the item from the calculations, the complementary number less one is set up on the stop field 3, and a subtraction key 42 is depressed and held in position by a latch 48. The key 42, which is mounted on a lever 43 pivoted to a shaft 44, has an arm 53 engaging a pin 56 on an arm 54 attached to a rock-shaft 55 which, on the depression of the key, is rocked and causes an arm 57 and link 58 to rock a lever 59 pivotally connected by a link 61 to an arm 62, which is thereby depressed to engage and throw out of action the stop plate 65, which normally prevents movement of the typesectors to the left of the highest significant figure by engaging projections 66 on the corresponding actuating-sectors 5. This ensures the introduction of the necessary number of the " 9 " digits. to form the complementary number. To permit the addition of unity to the units denomination of the totalizer 26, an additional hooked lever 29 is provided which co-operates with a pin 28 on the corresponding actuating-sector 5 and which is adapted to be raised, to allow the sector an additional step movement, by means of a bellcrank 67 rocked by means of a projection 72 pivoted to a special type-sector 70. The sector 70 which carries special type 71 such as clear signals, a character designating items listed by error, &c., has a projection 72 provided with a lug 73 arranged to engage a shoulder 74 on a stepped stop member 75 which is rocked, to present a particular step 76 to the lug 73, by means of a link 79 supported by a pin-and-slot construction 80 and having a pin 78 engaging an arm 77 connected to the key-lever 43. During an operation, the type-carrier is moved to bring the designating character opposite the erroneous item, and at the end of such operation the latch 48 of the key-lever 43 is freed to permit the key 42, and stop member 75 to return to normal position. To prevent printing of the complementary number, the usual hammer-latch release-bar 16 is held in position to prevent the shoulders 15 on the hammer latches 12 from rising in front of the bar 16. The bar 16 is pivoted at one end to a fixed support, and at the other end is attached to an arm 18 adapted to be rocked by a cam 21 on the main shaft 23, and in the normal or adding operation will be rocked to engage and to release the projection 15 of the hammer latches 12 to free the hammers 7. To hold the bar 16 from movement, a bifurcated member 82 embraces the bar 16, the said member being connected to the lever 59 actuated by the key-lever 43. Line-spacing mechanism. - The mechanism comprises a ratchet-wheel 30 on the platen spindle, and a pawl 31 mounted on an arm 32 on a shaft 33 adapted to be rocked by an arm 34 carrying a roller 41. The roller engages an arm of a bell-crank lever 40 connected by a link 39 to an arm 38 on the main shaft 23. To prevent the line-spacing mechanism operating during the correction or subtraction operation, an arm 84 which forms part of the lever 59 is moved into the path of a pin 86 on the arm 34 to limit its movement and prevent the pawl 31 engaging the ratchet-wheel 30.