Patent GB-896312-A (GB)
Title: Adding machine
IPC: A61B10/00
Filed: 1958-09-15
Abstract: 896,312. Digital electric calculating-machines. KIENZLE APPARATE G.m.b.H. Sept. 15, 1958 [Sept. 18, 1957], No. 29501/58. Class 106 (1). The differential members of a keyset calculating apparatus which position printing mechanism are caused to transmit pulses to an electronic accumulator which replaces the usual totalizer, and to be positioned under the control of the latter. Differential rack bars 1 when released by a camcontrolled bar 4 are positioned to the right under the control of a pincarriage 8, and have teeth 2 for setting the printing mechanism. Each rack bar 1 carries a gear-wheel 11 rolling on an associated rack bar 14 which moves to the left under the action of a spring 15 when released by a cam-controlled bar 16 which leads the bar 4 by one step. The bars 14 have teeth 18 engageable by solenoidcontrolled arresting pawls 19. The bars 4 and 16 also control a rack bar 40 and a rack bar 20 arranged to rotate respective slotted discs 45, 23 which in co-operation with photo-cell arrangements produce nine and ten pulses respectively during each setting half-cycle of the mechanism. Read-out from accumulator.-The ten pulses produced by the disc 23 are applied to all orders of the accumulator and each order produces a transfer pulse as it passes through zero. The transfer pulses may or may not be caused to switch off the cycling pulses so that accumulator is zerozied, but, in either case are applied to the respective solenoid 19 to arrest the racks 14 in complementary positions. After eleven steps of rotation of each wheel 11, it is arrested by a stud 12. Thus each rack 1 is arrested after a number of steps corresponding to the true digital value read from the corresponding order of the accumulator plus one. The type are so connected to the racks 1 that the true digital values are printed. If the accumulator contains a negative balance (in complementary form), then under the control of the switch 55, Fig. 2, the operation of which is described below, the slides 50 on the racks 1 against which the studs 12 normally move into abutment are shifted to ineffective positions and a plate 54 is raised so as to cause parts 53 pivoted to racks 52 to arrest the racks 1. Each rack 52 engages a pinion 51 also engaging the corresponding rack 14 and thus the rack 1 is arrested after the same number of steps as the rack 14, which is equal to the tens complement of the digit read out. As the digits printed are one less than the number of steps of movement of the racks 1, they correspond to the nines complement digits, i.e. to the true negative total. Additive entry into accumulator.-During setting movement of the rack bars 1, the pulses produced by the disc 45 are applied to each order of the accumulator through a contact strip 32 carried by the control bar 4, contact elements 33, 30 carried by the rack bar 1 and a fixed strip 31 for that order. When the rack bar 1 is arrested by the set pin of the pin carriage 8, the connection between the strip 32 and the element 33 is broken and so no further pulses are applied to that order. Tens transfers take place in the accumulator during entry in known manner. During an entry operation, the rack bars 14 and 20 are held inoperative under the control of a solenoid 29. Subtractive entry into accumulator.-To perform subtraction, complementary entry is effected and, for this purpose, a slotted contact strip 34 is made effective in place of the strip 30. Then, during the setting movement of each rack bar 1, no pulses are passed to the associated order of the accumulator until the bar 1 is arrested when further movement of the control bar 4, through a projection 39, cams a contact pawl 36 carried by the bar 1 into a corresponding slot of the strip 34 so that the remaining pulses produced by the disc 45 are applied to the accumulator. To correct the complement and to provide for the entries of the fugitive one, tens transfers from the highest orders are applied to the lowest order. A switch 55, Fig. 2, registers the sign of the total. Its arm is actuated in positive and negative directions respectively by electromagneticallyoperated pawls 61 and 63, and ratchet wheels. The pawl 61 is actuated when the add key is depressed and also on the occurrence of a transfer from the highest order to the lowest, whereas the pawl 63 is actuated on depression of the subtract key. The switch has one positive position and two negative positions, the latter providing for subtraction from a negative total. In that case, the switch is initially in its first negative position and on depression of the subtract key is moved to its second negative position. The operation produces a carry from the highest order to the lowest and this causes an actuation of the switch in the positive sense which leaves it in the first negative position to register the negative sign of the resulting total.