Patent GB-575324-A (GB)
Abstract: 575,324. Calculating apparatus. BROIDO, D. Dec. 10, 1943, No. 20729. [Class 106 (i)] A machine for calculations involving non- uniform numerical systems is adapted to multiply decimal multiplicands by decimal or sterling multipliers and sterling multiplicands by decimal multipliers and to divide decimal dividends by decimal dividers and sterling dividends by decimal or sterling dividers. The machine comprises a set-up mechanism for one of the factors, a conversion mechanism having physical representations of the decimal and non-decimal multiples of the set-up values and unit values of the other, factor, a products register, a feeler mechanism to transmit the set-up values to the register, a revolutions counter, and driving and operating means. Set-up mechanism and conversion mechanism. The values are entered by setting levers 5 rockably mounted on a shaft 6 supported in the side plates of a laterally movable carriage 9. Associated with the setting levers are bails 17, 18 that carry the sets of selector plates 16 constituting the conversion mechanism and arranged in five banks, Figs. 9 and 9A. A manually-operated restoring bar 22 serves to return the setting levers and plates to initial position. The selector plates 16 are notched and these notches are arranged in two groups, one on the right to represent the decimal multiples as described in Specification 566,942 and the other on the left to represent the non-decimal multiples, i.e. the multiplication of decimal amounts by shillings or pence, The arrangement of the notches for the selector plates 16 associated with 700 (or ú700) and 7d designated L10<2>(7) and D7 are shown in Fig. 8, in various denominational positions of the carriage. A separate plate 58 with a single notch is provided for the tens of shillings. Carriage shift mechanism. The carriage is .provided with rollers 34, Fig. 9, running on rails 25, 26 and a spring 27 tends to pull the carriage to the left. The movement is controlled by an escapement comprising a manipulative lever 33, a pawl 30, a pawl 38 and fixed rack 32, Figs. 9, 11 and 12. A further control for a carriage shift is provided in the positions for non-decimal multipliers. The arrangement comprises four stop plates 43 ... 46 for the tens of shillings, units of shillings, pence and eighths of a penny respectively. These plates are pivoted on a pin 47 on a fixed bracket and are held in normal position by springs 49. Each plate is formed with a tooth 51 and hump 52 for co-operation with a plate 53 secured to the carriage 9 adjacent the escapement pawls. Depression of the lever 33 rocks the pawl 30 so that an abutment 41 thereon by engagement with a hump 52 depresses the corresponding plate, say 46, to disengage plate 53 from the tooth 51 to allow carriage to travel to the left until arrested by the next stop plate 45. The carriage is restored by a hand wheel 54, Fig. 9, with a pinion 56 engaging a rack 57 on the front rail 25. Feeler mechanism. The selector plates of the various banks when set are aligned with sensing pins 21, not all of which are equally spaced as shown in Fig. 8, having regard to the numerical system involved. The sensing pins 21 coact with five pronged feelers 60 pivoted to gear sectors 62 rockable on a shaft. 63. Each gear sector 62 is connected by pin and slot means to a spring-controlled bracket 64 also rockable on the shaft 63. The brackets are engaged by a restoring bail 69 carrying a roller 71 which engages a cam 72 on the main operating shaft to reciprocate the brackets and gear sectors five times during a cycle of operation. To each feeler 60 is pivoted a link 73 that is connected at its other end to a bar 75 mounted on arms 76 carrying a roller 77 which engages a cam 78 so as to align the prongs successively with the banks of sensing pins prior to each reciprocating movement of the gear sectors. The depth of the notches determines the amount of movement of the gear sectors. The sensing pins are guided in brackets 81 and are biassed towards the rear of the machine by springs 82. The gear sectors 62 have lower extensions 83 that co-operate with locking pawls 84 to hold them against movement depending on the position of the carriage. In the decimal multiple and non-decimal multiple positions the appropriate pawls 84 are operated to release the sectors by a knock-out plate 87 fixed to the carriage. In Fig. 8, part of the knock-out plate is shown diagrammatical by a line 59. Results register. Each gear sector meshes with a pinion 88 loose on a shaft 89 and connected by a one-way drive to a gear 92. One or other of a pair of reversing gears 95, 98 transmits the movement to the corresponding gear 101 of the numeral wheels 104. Transfer between adjacent denominations is effected by allowing an additional step movement to the gear sector of the higher denomination in the manner described in the above-mentioned Specification. Revolutions counter. The revolutions or quotients are indicated on numeral wheels 127, Figs. 9 and 13, loose on a shaft 128. Each wheel has a gear 130 in mesh with idler gears 138, 139. A driver 141 shiftable along an operating shaft 142 in unison with the carriage drives the idler gears 139 to actuate the numeral wheels..For transfer purposes each numeral wheel has a single toothed pinion 135 that co-operates with a rocker 136 to displace. a cam surface thereon into the path of rocking pins 151 on restoring cams 152, which pins are arranged to act successively on the idler gears 138 to effect carry over. The shaft 150 carrying the restoring cams 152 drives through gears 147, 148 and 149 the shaft 142. In the carriage position for non-decimal multipliers, the gear 139 for the D numeral wheel 127 meshes with a gear 144 on the wheel, the gear 139 for the D / 8 numeral wheel is fixed to a gear 145 that meshes with the gear 130 on the said numeral wheel. The rocker 136 associated with the S10 numeral wheel is secured by means of a bar 146 to the rocker 136 associated with the -1 numeral wheel in the decimal multiplier section. Driving and operating means. The machine is operated by a hand crank geared to the main shaft 160 and to the carry shaft 150 through a manually settable clutch reversing mechanism so as to condition the machine for multiplication and addition, subtraction or division.