Patent GB-368254-A (GB)
Title: Improvements in or relating to calculating machines and the like
IPC: G06C21/04
Filed: 1930-10-01
Abstract: 368,254. Calcul at in g-apparatus. BURROUGHS ADDING MACHINE CO., 2nd Avenue, Detroit, Michigan, U.S.A.- (Assignees of Bower, R. G.; 16809, Baylis Avenue, Detroit, Michigan, U.S.A.) Oct. 1, 1930, No. 29384. Convention date, Oct. 2, 1929. [Class 106 (i).] A calculating machine is provided with a mechanism for checking the accuracy of the work of the operator. This mechanism is adapted to be set during the entry of an item and automatically prevents a predetermined subsequent operation except when for this second operation the same keys are depressed in the same succession as for the first entry of said item. In posting a commercial ledger the operator enters a customer's old balance on the keyboard and operates the machine to enter the amount in a totalizer and to print it in the " pick up " column of the ledger sheet. At the same time the proving mechanism is set in accordance with the entry and the paper carriage tabulated to the columns where " charges " or " credits " are to be entered. After posting these amounts the carriage tabulates to a " balance " position where the new balance is printed. The carriage then moves to a " proof " column where the old balance is again entered, the machine being free to operate only when the second entry agrees with the first entry. Additional controls are provided for the operation of the machine, the same being associated with the carriage return mechanism, and the subtraction key. The invention is shown applied to a ten-key type of machine as described in United States Specifications 1,336,904 and 1,143,240. The machine as shown in Figs. 1, 2, and 3 comprises the usual typewriter keys 3, numeral keys 4, a subtract key S, an errors key E, and a motor start key M. The numeral keys on depression co-operate through levers 5 with thrust bars 7 adapted to displace corresponding pins 10 in a field of pins on a travelling pin carriage 11 movable step by step by an escapement mechanism. The rear ends of the key levers 5 are positioned beneath a plate 15, Fig. 4, on a thrust bar 16 the upper end of which coacts with a pin 23 on an arm 20 pivoted to one of the carriage runways. A projection 19 on the arm 20 cooperates with a rack 18 on the pin carriage ; when the bar 16 is raised the projection 19 releases the carriage which is permitted a limited movement by engaging a projection 25 on the bar.16, the step movement of the carriage being completed when the depressed key is released. After entering an item the main shaft 26 is rocked and the pin carriage is raised to cause its projected pins to displace corresponding pins in a stationary field of stop pins 30 into the path of projections on the totalizer actuating racks 32. These racks co-operate with totalizers 34, 35, adapted to be rocked into engagement therewith at appropriate times in the cycle for effecting the calculations. The racks carry type members 36 positioned relatively to a platen 37 carried on a paper carriage 38. Proving mechanism. The proof mechanism includes a set of pins 50, Figs. 2 and 3, carried by an extension 51 of the pin carriage 11. The pins 50 are arranged in rows and the number of rows and of pins in each row are the same as the pins 10. The proof pins 50 are adapted to be projected by extensions 52 on arms 53 pivotally mounted on a shaft 54 carried by the arms of a yoke member 56 journalled on a shaft 57 itself journalled in stationary members 59. The arms 53 are supported for sliding movement on a shaft 58 the shaft being accommodated in an elongated slot 60 in each arm. Normally the arms 53 cannot be rocked about their pivots 54 since the shaft 58 engages the closed end of the slots 60 as shown in Fig. 2. When it is desired to condition the proving mechanism to receive an entry the arms 53 are moved to the left, Fig. 2, so as to bring the projections 66 thereon into the path of pins 64 on extensions 65 of the thrust bars 7 so that when a bar is raised the corresponding arm 53 is rocked to displace the appropriate proof pin 50. The movement of the arms 53 is effected when the paper carriage tabulates to the " pick-up " column by means of a cam stop 70 adjustably mounted on the carriage engaging a roller 71 to rock a yoke member 72 and depress a link 75 connected at its lower end to an arm 77 fixed to the snaft 57. The rocking movement of the shaft 57 is imparted, through a bell crank 78 and spring 80, to an arm 81. on the yoke member 56 thereby moving the arms 53 to the left. When the carriage leaves the " pick-up " column the link 75 rises under spring action and the arms 53 move to the right to Fig. 2 position to the inactive position with respect to the proof mechanism so that the machine is free to perform other operations. When the carriage reaches the " proof " column a larger cam 84 adjustably mounted on the carriage rocks the yoke member 72 to depress the link 75 through a greater distance. This additional movement through the arm 85 of the bell crank 78, a link 86, and bell crank 87 depresses an irregular shaped member 89, Figs. 3, 10, and 11, having an extension 91 with cam surfaces 92, 93. co-operating with a latch 101 and a pin 94 of a locking plate 95, whereby the proof pins 50 are locked in set position by the plate 95 engaging the upper or lower notch of the pins on its movement from the position of Fig. 10, to that of Fig. 11. The latch 101 is held disabled in the " pickup column by engagement of the cam 92 with a pin 100 on the latch. By this locking action only those keys that were depressed in the " pick-up " column can be depressed in the " proof " column. The machine operation is prevented until all of the keys previously depressed have been again depressed by the provision of a comb-plate 110, Fig. 3, arranged over the field of proof keys 50. The comb-plate is supported on a shaft 111 by means of a spring 112 attached to an extension 113 of the member 89 and is provided with a downwardly extending link 114, Fig. 12, with a pin 115 at its lower end engaging a slot in a stationary plate 116. Pivoted on the pin 115 is a lever 117 with a bifurcated end engaging a pin 118, Fig. 13, on an extension 119 of the member 89 and with a lateral lug 120 adapted to coact with a hook 121 on an extension of a sliding rod 123 connected at its forward end to an arm 124, Fig. 1, which is itself connected by a spring 126 to a bell crank 127 operated by the motor key M. In the " proof " column the lowering of the member 89 moves the lever 117 from the position shown in Fig. 12 to that in Fig. 15 where the lug 120 encounters the hook 121 on the rod 123 and prevents operation of the motor key M until the comb-plate 110 is free of the displaced pins 50. When all the keys that were depressed in the " pick-up " column have been depressed in the " proof " column the combplate is permitted to move to the horizontal position thereby effecting a lowering of the bar 114 and of the pivot pin 115 of the lever 117 freeing the hooked end 121 of the sliding bar. Carriage lock. The carriage return mechanism, Fig. 16, comprises the usual power shaft 130, clutch 131, and gearing 132, 133, the clutch being normally disengaged and rendered active by rocking a lever 135 connected by a rod 136 to the carriage return key CR. In the " proof " column the initial movement of the member 89 through a bell crank 137, Fig. 1, pivoted on the bar 114 and a linkage 139, 140, positions the upper end of an arm 142 under the lever 135 to prevent its operation. The removal of the arm 142 to free the lever 135 is effected by the lowering of the bar 114 through the comb-plate after all keys have been depressed. This movement lowers the pivot of the bell crank 137 and displaces the linkage and arm 142. Subtract key control. The subtract key S is connected through a bell crank 150 and rod 152 to a U-shaped member 153 one arm 154 of which has a hooked end 155, Fig. 17, adjacent the lug 120 on the lever 117 while the other arm 156 is provided with a slot 157 engaging a stud 158 on one arm of a bell crank 160 carrying a latch 164 adapted to engage a stud 167 on the stationary plate 116. The latch 160 has a shoulder 168 adapted to engage behind a pin 169 on the member 89 and the other arm of the bell crank 160 is connected by a link 171 and yielding connection to a bell crank 172, Fig. 1, movable to a position to prevent operation of the carriage return lever 135. If the subtract key is depressed when the carriage is in the " pick-up " position the movement of the member 153 rocks the bell crank 160 and when the key is released the parts assume the position shown in Fig. 18 with the latch 164 engaging the stud 167 and the arm 174 of the bell crank 172 under the lever 135. As the carriage moves to the " proof column the lowering of the member 89 causes the pin 169 to strike the outside edge of the arm 159 of the bell crank 160 and to free the latch 164. If the subtract key is now depressed the bell crank 160 is rocked further until the shoulder 168 snaps behind the pin 169 in which position the arm 174 has been removed from its position under the lever 135. The operation of the subtract key is deferred until after the amount keys have been depressed since only on the lowering of the bar 114 by the comb-plate is the lug 120 on the lever 117 withdrawn from the path of the projection 155. If the subtract key is not depressed in the " pick-up " position the downward movement of the member 89 in the " proof " column causes the pin 169 to engage the inner edge of the arm 159 and locks the bell crank 160 against movement to prevent depression of the subtract key in this column. Restoring mechanism. In order to restore the operated pins 50 it is necessary to raise the comb-plate 110 after it has been lowered in the "proof " column. For this purpose an arm 180, Fig. 12, pivoted on a shaft 181 is bifurcated to engage a pin 183 on the bar 114 and carries an extension 184 with a cam surface 185 co-operating with a stud 186 on an