Patent GB-351007-A (GB)
Abstract: 351,007. Calculating apparatus. TRIGGS, W. W., Lincoln's Inn Fields, London.-(Sundstrand Corporation ; 100, West 10th Street, Wilmington, Delaware, U.S.A.) March 15, 1930, No. 8439. [Class 106 (i).] A calculating machine has two totalizers, means for causing both to be engaged simultaneously with the actuating racks and means under the control of the setting-up means for preventing one of the totalizers from being engaged in an operation of the machine not consequent to the setting-up of a digit. The invention is described as applied to the Sunstrand machine. Each of the two totalizers 125, Fig. 7, may be engaged with an actuating rack 129, 130, but each rack has only one totalizer engaging it at one time. The engagement of the upper totalizer with the racks is effected by a link 137 pivoted to a lever 139 carrying two pins 156, 157, Fig. 4, which are engaged alternatively by the hook-shaped parts 158, 159 of a link 141. A similar lever 139a having pins 156a, 157a engaged by a link 141a controls the lower totalizer. The links 141, 141a are connected by a link 160 urged to the left by a spring 285, and may be moved from their lower position shown in Fig. 4, in which the pins 157, 157a cause the totalizers to be set for addition, into an upper position in which the pins 156, 156a effect the engagement of the totalizers for subtraction. In addition the upper totalizer is actuated by the rack 130 and the lower one by the rack 129 and vice versa for subtraction. The links 141, 141a are moved horizontally by a slide 144 which reciprocates from its normal (Fig. 4) position to the left and back again during the operation of the machine. The slide 144 is connected to the links 141, 141a by pin-and-slot connections 142, 143, and carries also, by pin-and-slot connections 281, 282, a vertically adjustable slide 280. The position of this latter slide is determined by the manual setting of a lever 292 to which it is connected by a link 290 pivoted at 289 to a lever 286 having a pin 287 engaging a slot 288 in the slide 280. When the lever 292 is in its upper position, the slide 280 is moved downwards from its mid-position shown in Fig. 4, the link 141 moving to the left to move the upper counter into a neutral position and the link 141a to the right to engage the lower counter and to take up the lost motion between the lower pin 143 and its slot 142. The operation of the machine then causes the actuation of the lower totalizer only. Similarly when the lever is in its lower position, the slide 282 moves upwards and the upper totalizer only is actuated. When the lever 292 is in its midposition, both totalizers function, the upper one because in the mid-position of the slide 280 the lost motion has been eliminated from the upper connection 142, 143, and is eliminated from the lower connection by the rising of a link 295 pivoted to a crank 300 on a shaft 301 to insert a bridgepiece 296 between the pin 143 and a pin 297 fixed to the link 141a. The shaft 301 is connected through a two-piece yieldable crank to a vertically moving link 311, Fig. 1, guided by a fork embracing the stationary axis 6. A slot in the end of a lever 324 pivoted at 312 engages a pin 315 on the link 311. To the upper arm 324 is attached a dog 325 yieldable against spring pressure in an anticlockwise direction only and lying in the path of a pin 328 on the lever 5. A second pin 318 also contacts with a cam surface 316 yieldably attached to the horizontal arm of the lever 324. The motion of the link 311 may be inhibited by the engagement of a catch 329 with a slot 331 therein. This catch is connected by a link 332 to a lever 336 pivoted at 337 and urged by a spring 338 to hold the catch in an inoperative position. The action of the spring is prevented by a roller 73 acting on a projection 344 of the lever 336, the roller being connected to a member 72 which moves to the left whenever a digit is set on the machine. Thus if no digit is set the link 311 cannot move. With the lever 292 in its central position, and with an item set on the keyboard, the slide 144 moves to the left to place the upper totalizer in a neutral position and the lower pin 143 moves away from the pin 297. The pin 318 then meets the cam 316 and moves the link 311 downwards to insert the bridgepiece 296. At the commencement of the return stroke of the handle, the slide 144 moves to the right and the amount is accumulated in both totalizers. During a second similar operation, the link 311 is restored to its upper position at the commencement of the first handle stroke by the pin 328 and dog 325 but is shortly afterwards reset again by the pin 318 and cam 316. Without moving the lever 292 the total of a group of items can be taken from the upper totalizer, and that totalizer cleared, the total still remaining in the lower totalizer. To effect this, a blank operation is first made, during which the bridge-piece 296 is withdrawn and locked down by the locking of the link 311, the lower totalizer moving into its neutral position. The total key is then depressed and the handle operated. The slide 144 is now stationary during the first stroke, and moves to disengage the upper totalizer at the commencement of the return stroke and to engage it at the end thereof. To obtain the grand total from the lower totalizer, the lever 292 is moved to its upper position and the blank and total-taking operation performed in the usual manner. It is necessary to prevent the operation of the bridge-piece 296 when the lever 292 is in its lower position, and for this purpose a lever 339 pivoted at 341 engages with a roller on the lever 292 and through a lever 342, moves the link 332 to the right to insert the catch 329. A locking member connected to the total key prevents the movement of the lever 292 after the latter has been depressed and a spring-operated detent 358 engages notches in the bar 290 to lock this bar as soon as movement of the operating handle 11 commences.