Patent GB-886123-A (GB)
Title: Electrical multiplying apparatus
IPC: G06F7/52
Filed: 1960-08-02
Abstract: 886,123. Electric multiplying apparatus. NATIONAL CASH REGISTER CO. Aug. 2, 1960 [Aug. 3, 1959], No. 26655/60. Class 106 (1). The product of two decimal factors is accumulated in a product accumulator and set up also in a product storage device, the tens complement of the first factor is multiplied by the second factor and the resulting product is also entered into the product accumulator, after which a test is made to see if the significant digits of the product and the second factor correspond. Mechanical arrangements. The invention is applied to an Ellis machine of the type described in Specification 680,992 to which an electromechanical device of the type described in Specification 550,978, has been added. The machine includes several totalizers selected by keys. A multiple card key 26,multiplier key 27, and product key 28 (Fig. 2, not shown), operate switches by cam action. Amount keys control the movements of differential racks and under the control of solenoids operated by the function keys information is set up on switches 120- 122. As an example, the multiplier is set up on switches 121, Fig. 3B, as follows. The multiplier switches comprise a basket with ten rows of ten contacts forming a memory unit which can be moved up or down by multiplier solenoid L 104. When a rack assumes a position corresponding to a digit a finger 132, Fig. 6, lies under the contact corresponding to the digit and denomination. When the multiplier solenoid L104 is energized it shifts the basket of contacts downwards towards the racks whereby the selected switch keys 145, Fig. 8, are pushed relatively upwards and held by a retainer 147. When the solenoid deenergizes the basket returns upwards and switch key contacts 146 of operated keys 145 complete circuit between associated switch contacts 156. The contacts 156 are connected to the multiplier and shift rings in the multiplying device. The check switches 122, Fig. 6, are mounted below the racks of the accounting machine opposite the multiplier switches and are operated under the control of check solenoid L105 (not shown). The product switches 123, Fig. 6, are used after the product has been verified to transfer the product from the multiplying device to the accounting machine. They comprise a wiper 227 and set of contacts 226 for each denomination, Fig. 10. One contact in each set is marked by a high potential from the multiplying device. Each wiper is driven by shaft 99 through a slip clutch 235, Fig. 11 (not shown), until it finds the high potential when an associated magnet 242, Fig. 6, energizes to insert a stop 233. The angular position of each wiper 227 is transmitted, when product solenoid L106 is energized, through pinion 250 to the associated rack through the co-operation of an extra tooth 256 on the pinion and a rack stop 257. A product set up on the racks may also be transferred to the multiplicand switches 120 but then it is automatically divided by 100. It may also be transferred in normal manner to the multiplier switches 121. As the racks return to home position a product may be transferred to a totalizer or be printed. A cam-shaft 397, Fig. 18 (not shown), operates switches concerned with multiplicand, multiplier, check, recording, start, carriage position, product, and multiply at different points of the machine cycle. The multiplying device is controlled automatically by the travelling carriage in preselected columnar positions by a carriage position switch mechanism in the manner described in Specification 808,651. Stops 412, Figs. 20, 21, are inserted at predetermined positions on a bar 410 secured to the carriage. Studs 413 in the stops operate one or more of twenty sets of contacts in carriage position switch SC140 to initiate operations which vary with the position of the carriage. For example, when the carriage arrives at a position at which a product is to be transferred from the product switches 123 to the accounting machine lever 459 senses the lower ear 416 of a stop 412 to operate switch SC106a. Multiplying apparatus. When the two factors have been set up on the multiplicand and multiplier switches 120, 121, Fig. 23, manual or automatic operation of the multiplication switch initiates multiplication during which the product is transferred to the product switches 123, Fig. 24. Checking consists of adding the product of the multiplicand and the tens complement of the multiplier to the first product and comparing the significant digits of the total with the digits of the multiplier. If the digits are in agreement, with appropriate denominational shift, then the product is transferred to the accounting machine. If the check fails the multiplication repeats. A lamp on the keyboard is lighted until success is achieved. A generator 500, Fig. 22, supplies 0 pulses at a frequency of 10,000 c.p.s. It also supplies 180 pulses which are used only in those cases where entry of items into an accumulator stage may be made from two sources, the 180 pulse from the second source being then timed so as not to coincide with the pulse from the first source. Multiplicand ring, Fig. 22. The generator feeds pulses to the multiplicand ring 503. This ring comprises 11 two-grid thyratrons Fig. 27 (not shown), in which the first thyratron is permanently primed. Each tube when fired primes the next. The tubes thus fire to successive pulses and continue to conduct until the eleventh or tally tube energizes a blow-out circuit 505 which cuts-off all the tubes in the ring. As each tube begins to conduct it applies a potential to an output terminal. Excluding the first tube, the ring therefore provides a potential sustained for different lengths of time on each of its nine output lines, the times beginning successively but ending simultaneously. The ring operates continuously. The multiplicand has been set up on the array of switches 120, Fig. 23. An operated multiplicand switch feeds the corresponding timed potential from ring 503 to one of multiplicand gates 507. The multiplicand gates, Fig. 28 (not shown), comprise a triode for each digit place in the multiplicand. The timed potential is applied to the control grid of the associated triode which then conducts at each 0 pulse from the generator 500 while the timed potential lasts, whereby the triode produces a series of pulses corresponding to the digit set up on the switch 120. Each time the multiplicand ring 503 goes through a cycle the triodes produce pulse groups corresponding to the digits of the multiplicand on the appropriate outlets. These pulse groups are transmitted down different paths through shift matrix 508 to the accumulator 509, Fig. 24, under the control of multiplier circuits. Multiplier circuit. The multiplier circuit counts the number of pulse groups fed through shift matrix 508 and when that number is equal to the lowest digit of the multiplier it initiates a shifting operation. The process repeats for each digit of the multiplier. A multiplier ring 510, Fig. 22, is of the same type as multiplicand ring 503 and is advanced by tally pulses from the multiplicand ring. When the number of tubes fired reaches the digit set up in the operative column of multiplier switches 121 the appropriate denominational tube in shift ring 511 operates a blow-out circuit to extinguish all the tubes in the multiplier ring. A new count then begins in respect of the next digit. The multiplier switches 121 are connected between multiplier ring 510 and shift ring 511, the tubes of which fire one at a time and in sequence. While each tube in ring 511 conducts it opens a set of gates in the matrix 508 to direct the pulse groups to the appropriate stages of the accumulator 509. When the multiplier ring has counted up to the digit set up on the appropriate column of the multiplier switches the next tally pulse from ring 503 fires the next tube in the shift ring 511. This tube develops a shift pulse which delays operation of the multiplicand ring 503 for two 0 pulses and causes blow-out circuit 512 to clear the multiplier ring, as mentioned above. Shift matrix 508, Fig. 23, and Figs. 35, 36, 40 (not shown), comprises 77 diodes which respond only to coincidence of a pulse and a priming voltage, the pulses being supplied by multiplicand gates 507 and the priming voltage by the operative tube of shift ring 511. The pulse groups from matrix 508 are amplified at 517 and applied to the appropriate stages of accumulator 509. The first three stages of the accumulator do not have read-out but are concerned primarily with producing carry pulses. For round-off purposes, therefore, the third stage is set initially at 5 instead of 0. Each stage of the accumulator comprises four flip-flops arranged in binary plus-2 fashion. When the accumulator has counted all the pulse groups the product is set up on the product switches 123 while being retained in the accumulator. Check. A second multiplication ensues in which switches 520, Fig. 23, are reversed so that the tens complement of the multiplicand is involved. The apparatus is designed to deal with a multiplicand having a maximum of three digits to the left of the decimal point so that the sum of the two multiplications is 1000 X the multiplier. The last three diodes in matrix 508 are operative only in the second multiplication, as are end-around amplifiers 524, 525 which feed overflow pulses to Bank 1 and 2 stages of the accumulator. The sum of the two products is then set up on check switches 122 with appropriate denominational shift. If the digit in a check switch agrees with the digit in the associated product switch 123 then the corresponding product magnet 242 energizes. If all the product magnets energize then release relay K108, Fig. 43 (not shown), operates and the product is transferred to the accounting machine. Accumulator. Fig. 39 shows one stage of the accumulator 509. Negative input pulses are applied at 911 to the first of four binary