Patent GB-191327655-A (GB)
Title: Improvements in and relating to Methods of Calculating & Calculating Apparatus.
Inventor: WHITE ALFRED ERNEST
Filed: 1913-12-01
Granted: 1915-01-01
Abstract: 27,655. White, A. E., [National Cash Register Co.]. Dec. 1. Adding- apparatus is arranged so that (1) when digits of greater value than 5 are added in any denominational bank of the machine, the adding operation is performed by subtracting the complements of the digits: no adding- wheel or differentialmember thus moves through more than 5 steps in the operation of adding any item, although in such operation the processes of direct addition and of subtraction of the complement go on without other manual control than the normal working of the machine by hand or otherwise. (2) Transfer mechanism is adapted (a) to act normally during the usual additive transfer and (b) to be set in any bank as soon as a key. above the value of 5 is depressed in that bank with the consequent subtraction of the complement, but (c) to be reset, i.e., to be inoperative, in that bank if the particular n u m e r a ldrum when rotating in the subtractive direction passes beyond the zero position. (3) An indicator is provided to indicate the value of the depressed key. Keyboard interlocks; error keys. - In the lever-operated multiplebank apparatus shown the depression of the keys 1, Fig. 2, of any bank moves the arcuate latching - bar 7, Fig. 7, causing the upper notches of the key-stems to be engaged by the studs 8. The latching- bar can be raised and released by the depression of the error key 130 or at the end of the operation in the normal course by a cam on the main shaft 46 through a rod 144 and lever 143, 141. Keyboards; differential mechanism. - Depression of keys 1...5. With each bank of keys are associated two notched plates 30, one of which has five inclined notches co-operating with the five upper keys which are of the values 1 ... 5, and four radial notches coacting with the four keys of values 6 ... 9; in the second plate this arrangement is reversed. If one of the keys 1 ... 5 is depressed the stud 33 thereon engages the inclined notch of the outer plate shown in Fig. 2, and the radial notch 34 of the left-hand plate. Thus the former plate is depressed while the latter is locked, the movement of the former lifting the foot of a lever 26 from the stud 24 of a lever 21. As soon as the operation of the lever is begun, arms 25 on shafts 4 are raised from the boss 23 of the lever 21 by a cam 49, Fig. 10, allowing, in the present instance, the spring-controlled lever 21 to depress a rod 17, Fig. 3, carried by parallel links 18, from its engagement with a fixed toothed arc 40 and into engagement with the shoulder 37 of the upper one of two driving-segments 16. The ensuing counter-clockwise movement of the segment on its shaft 15 causes it to carry the rod 17 and the actuating-rack 14, which supports the rod until a projection 38 on the lever 21 strikes the stem of the depressed key, whereupon the lever is turned in a clockwise direction and the rod 17 lifted clear of the rack 14 and into engagement again with the fixed toothed arc 40. During the continued movement'of the segment, the lower end of the rod 17 is in contact with the curved periphery of the segment, and is therefore locked in position. The return movement of the driving-segment 16 returns the rack 14 owing to the engagement of the segment with a lug 41 on the rack. The differential mechanism is that described in Specification 20,333/11. Depression of keys 6 ... 9. A considerable part of the mechanism just described is duplicated for co-operation with the remaining keys. There are two similar driving-segments 16 rotated in opposite directions by cams 53, 54, Fig. 2, on the main shaft 46 at each operation, i.e., two complete turns of the handle. Each of these segments is adapted to drive the single denominational actuating-rack 14 through one of the rods 17 mounted thereon as described above. The four lowest keys 6 ... 9 of each bank, however, cause the engagement of the lower rod 17 with the shoulder 37 of the lower driving-segment, and a differential movement of the corresponding actuating-rack in a subtractive direction and equal in value to the complement of the number represented by the depressed key. Totalizing-counters.-Toothed wheels 59 are in constant engagement with the racks 14. The accumulating-wheels 60 are mounted in sideframes 63, Fig. 5, and are rocked by means of a cam 66 and lever 70, 71, having a cam-slot 72, at the beginning of every operation of the machine so that the pinions 61 engage with the wheels 59. The wheels 60 are consequently turned during the ensuing process of addition in the additive or subtractive directions, according as the keys 1 ... 5 or 6 ... 9 are depressed. Transfer mechanism. - (a) In the normal additive (counter - clockwise) movement of the wheels 60, a tooth 73 at transfer strikes a projection 75 on a pawl 76, which, by means of a lug, rocks a trip-pawl 80 and allows the transfer pawl 84 to engage with the ratchet-wheel 88 of the next higher counting-wheel. At the end of every operation, transfer levers 78 carrying the pawls 84 are rocked by a cam 90 driven from the main shaft, the movement causing the pawls to drive the counting-wheels through one step and to be relatched by the trip-pawls 80. (b) At the beginning of every operation, the toothed wheels 59, which are in constant engagement with the racks 14, are in position with their studs 93 adjacent to trip-pawls 82. The initial movement of any wheel 59 in the subtractive (counter-clockwise) direction causes its stud to rock the pawl 82, a projection on which trips the pawl 80 and allows the transfer pawl 84 to spring into engagement with the ratchet-wheel 88. Transfer will then take place as usual upon the operation of the transfer lever 78 by the cam 90. (c) If, however, a wheel 60 rotating in the subtractive (clockwise) direction passes through or beyond zero, the tooth 73 will strike the projection 75 and rotate the pawl 76 in the counter-clockwise direction, the arm 96 engaging an upward projection on the transfer pawl 84, which has been released as soon as the wheel 60 commenced to rotate in the subtractive direction, and thereby re-setting it. Displaying items. - Indicating - drums 106, Fig. 2, for the item accumulated can be read, as usual, from the front or rear of the machine: the drums move directly from one indication to the next item set without previously returning to the zero position. The drums are actuated by links 99 from levers 98 pivoted to the actuating-racks 14; a hooked arm 117, Fig. 3, rocked from the main shaft engages a roller 118 on the lever 98 and determines the position of the lever and drum. Specifications 4550/10 and 18,642/12 are referred to.