Patent GB-718412-A (GB)
Abstract: 718,412. Calculating-apparatus. REMINGTON RAND, Inc. May 9, 1950 [May 12, 1949], No. 11536/50. Class 106 (1) A single-bank keyboard calculating machine comprises an accumulator settable for addition or subtraction, a movable pin carriage for receiving the entry of a numerical value and for controlling the movement of racks in accordance with such value to actuate the accumulator, and an operating mechanism under manual control for causing repeated accumulating operations according to a digit value of a multiplier, in combination with means for stepping the carriage having a multiplicand set up therein, a spaced leftward to increase the multiplicand ten times and for entering the increased multiplicand in the accumulator, the carriage being back-spaced upon such entry for a corresponding decrease of the multiplicand, said means including connections with the accumulator to reverse the position thereof for subtraction upon such entry, whereby subsequent actuation of the operating mechanism for a number of cycles corresponding to the ten's complement of the digit value of the multiplier when greater than " 5 " will produce a short cut multiplication. The invention is described as an improvement of the type of machine disclosed in Specification 681,271 and U.S.A. Specifications 2,203,336, 2,229,980, 2,237,881 and 2,255,622. The machine has a pin carriage 50, Fig. 8, urged to the left, Figs. 4 and 6, by a spring 57 and having stop pins 51, Figs 4 and 8, which are set by the stems 52 of the digit keys 53 and additional space stop pins 54, one for each column of pins, which are set by a key 56. The pin carriage is controlled by a known type of escapement mechanism 58, Fig. 6. The pins 51, 54 serve to differentially set actuator racks 59, Figs. 7 and 8, each connected to a slide 62 the heel 63 of which cooperates with the associated column of pins 51, 54. Each of the racks 59 is normally held against the pressure of a spring 64 by a bail rod 65 reciprocated, in known manner, during each machine cycle. Each rack 59 has teeth 66 which co-operate with accumulator pinions 67 and with pinions 68. The pinions 68 set type racks 73 which co-operate with hammers 75, Fig. 12, pivoted on a tie rod 76 and each urged clockwise by a spring 77. If, during a machine cycle, the heel 63 of a slide 62 is arrested by a space stop pin 54 an associated hammer block slide 100 is arrested by a lug 99 of the slide 62 in such a position that a projection 105 of the slide 100 lies under an extension 106 of the associated hammer 75 which is thereby prevented from operating and so no unnecessary " zeros " are printed. Control of type racks.-The pinions 68, Figs. 17 and 18, are carried by a shaft 72 laterally displaceable in frame plates 85, 86 and normally retained by a spring 112 in such a position that the pinions 68 are normally engaged with the type racks 73 but disengaged from the actuator racks 59. A hammer control bail rod 70, Fig. 17, is carried by an arm 114 controlled by a slotted cam 70A on the drive shaft 92. When the arm 114 moves clockwise a cam surface 80 thereon displaces the shaft 72 to the left, Fig. 18, to engage the pinions 68 and racks 59. As the racks 59 move rearwardly the type racks 73 are raised, a hammer latch bail 116, Fig. 8, is rocked counter-clockwise to free each hammer 75 to the action of its spring 77 and printing is effected. On the return stroke of the racks 59 the bail rod 70 is moved to return the hammers 75 and the spring 112, Fig. 18, returns the shaft 72 to the right. During non-printing cycles in multiplication and division the bail rod 70, Fig. 24, is blocked by a lever 71, in known manner, so that the shaft 72, Fig. 18, is not moved and the type racks 73 remain stationary. Each actuator rack 59 has three missing teeth at its inner end so that when a rack is arrested by a pin 54 it is disengaged from the associated type rack 73. When a lug 120, Fig. 8, on an accumulator pinion 67 depresses a pawl 121 to allow an additional transfer movement of the corresponding rack 59 no movement is imparted to the associated type rack 73. Movement of the type racks 73 during transfer operation is prevented by a comblike bail 124, Fig. 21, controlled by a roller on an arm fixed to the main shaft 92. Total taking.-The accumulator pinions 67 are meshed, in the known manner, with the rearwardly moving racks 59 and the type-racks 73 are set by the pinions 68. The hammer latch bail 116, Fig. 8, is rocked counter-clockwise to free the hammers 75 to effect printing. The pinions 67 are then raised from the racks 59. The bail 116, Fig. 10, then releases a series of spring- pressed pawls 137 each of which engages the adjacent teeth 136 of the corresponding rack 59 which is thus prevented from jumping rearwardly. As the racks 59 move forwardly the pawls 137 click over the teeth 136 and, finally, the bail 116 restores the pawls 137 to their normal position. The revolutions or quotient counter is similar to that described in Specification 681,271, but because of the short cut method of multiplication sometimes effected in the present machine the counter 145 has a rack 146, Fig. 2, which has two sets of type ; the normal column 147 and the complementary reverse column 148. Multiplication.-The multiply lever 151, Fig. 24, effects control of the machine cycles in the known way. Upon rearward movement of the lever 151 the lever 71 is positioned to prevent movement of the bail rod 70 and so prevent printing. A slide 155 is moved to effect rocking movement of an arm 162A which raises the rack 146, Fig. 3, and restores the counter 145 to zero. Rearward movement of the lever 151 also positions the pawl 170 to prevent " adding in the first machine cycle, moves a bell-crank lever 174 to cause the driving motor to start and positions arm 177 to prevent depression of the short-cut key 173. Normal multiplication is effected in the usual way and the carriage back-spacing mechanism is of the known type. When the revolutions counter indicates the first digit of the multiplier the multiply lever 151 is released and an additional cycle is performed during which printing, backspacing and adding is effected. The lever 151 is then actuated for the succeeding multiplier digits. On the last adding cycle of a multiplication the "units" actuator rack 198, Fig. 8, moves rearwardly to cause rocking of a bail 200 which in known way .disables the back spacing mechanism and allows restoration of the pin carriage. The bell-crank lever 174, Figs. 3 and 24, is retained in its .active position for a blank cycle followed by a total taking cycle. Short-cut multiplication.-A short-cut method of multiplying is employed when multiplying by a digit greater than " 5 ". Depression of a shortcut key 173, Fig. 11, conditions the machine for first and add cycles followed by subtract cycles. The key 173 when depressed is latched by a latch 215, Fig. 6, which engages a lug 213 of the key stem extension 209. Depression of the key 173 also causes counterclockwise rotation of a crank 220, and this movement is transmitted by a horizontal arm 224, a bail 231 and an arm 232 to cause momentary depression of the space key 56 which operates the escapement mechanism 58 through a bail rod 95. A pin 234, Fig. 24, on the stem of the key 173 moves the pawl 170 from its normal position so that the machine is conditioned to form an add cycle when the lever 151 is moved rearwardly. Depression of the key 173 also causes through a lever 237, Fig. 23, a link 241 and. an arm 242 release of the back-space lever 191 so that back spacing will be effected during the first add cycle. The multiply lever 151, Fig. 24, is now moved rearwardly and held there till the revolutions counter indicates the ten's complement of the multiplier digit. During the first machine cycle the multiplicand, as multiplied by ten by the above described momentary depression of the space key, is added into the accumulator 81, Fig. 8, and the pin carriage is back spaced. Also during this cycle the dial counter 145, Figs. 2 and 3, is moved in known manner from " 0 " to " 1." During the second half of this cycle a shaft 269, Fig. 23, is rocked counter-clockwise to disengage a negative hammer catch 273 from the hammer 150, Fig. 2, and to enable the positive hammer catch 274 to prevent firing of the hammer 279. At the same time a bail arm 277, Fig. 1, is raised and the known accumulator reversing mechanism is actuated to condition the machine for subtraction. Near the end of the first cycle a cam 194, Fig. 23, actuates the lever 191 to effect back spacing in known manner. During this back spacing the latch 215, Fig. 6, is released from the 'lug 213 of the stem of the key 173 which is returned by its spring 208. The machine now performs subtract cycles until the lever 151 is released. Upon restoration of the lever 151 the lever 71, Fig. 24, is removed from the bail rod 70 so that during the succeeding extra cycle printing of the multiplicand by hammers 75, Fig. 8, and printing of the multiplier digit by hammer 150, Fig. 2, are effected. During the second half of this extra cycle the cam 194, Fig. 24, actuates the pin carriage back spacing mechanism. A lever 295, Fig. 1, is rocked and a projection 296 moves the latch 283 to allow the hammer catch shaft 269 to return to normal position whereupon the hammer catches 273, 274 reverse to their normal positions. The arm 277 is freed and the accumulator reversing mechanism actuated to restore the pinions 67 to the " add " position. If the next multiplier digit is greater than " 5 short-cut multiplication is again performed by depression of the short-cut key 173 and then actuating the lever 151. If the digit is " 5" or less regular multiplication is effected. At the end of the multiplying operation the machine automatically performs a blank cycle followed by a total taking and printing cycle in known manner. Discount multiplication.-The short-cut method