Patent GB-303517-A (GB)
Title: Improvements in or relating to calculating machines
IPC: G06F7/46
Filed: 1929-01-04
Abstract: 303,517. British Tabulating Machine Co., Ltd., (Assignees of Bryce, J. W.). Jan. 5, 1928, [Convention date]. Multiplying-apparatus. - An electrical apparatus is described for multiplying two factors and recording these and their product by perforations in a record-cord. In the embodiment set forth the factors are entered and simultaneously punched on a statistical card by means of a single bank of keys and when the multiplying process is complete the product is punched automatically on the card with or without initiation of this last operation by the operator. The multiplication is effected electrically according to the method described in Specification 302,237 the partial products being formed by the use of the known four-point code and then transformed into the decimal series notation before being transmitted to the product counters of which there are two, one for receiving the units of the partial products of the digits and the other for receiving the tens. In the last stage of the operation the tens values are transferred to and entered in the units counter to present the final result. General arrangement. The cards 50, Fig. 1, are fed manually by a picker 62 into position below punches 46 operated by keys 66 or by electromagnets 104. The punching-mechanism may be as described in Specification 238,553, [Class 31 (ii), Punching and perforating machines &c.]. At the rear, starting from the left, are groups 341, 342 of multiplying elements, indicators for the multiplicand and multiplier set up, the two product counters and finally the driving- control devices. Punching-mechanism. The picker 62 is moved by a handle 60 against spring return, to position a card in its carriage with its first column under the punches. When a key 66 is depressed it moves a bar 68, Fig. 5, over the corresponding punch 64 and this through an universal bail 70 moves a contact bar 72, Fig. 8, to the left to complete circuit at 74 for an actuating magnet 76. The armature 78 being thus attracted swings a link 80 and bell-crank 82 to depress a pivoted plate 86 and so, through the interposed bar 68, to actuate the punch. An escapement mechanism then operates to shift the card one column space to the left to receive the next perforation. To prevent the immediate restoration of the punching-mechanism and the feed of the card during computing a latch 100 under the control of a magnet 94 seizes and holds the armature 78 until the magnet is de-energized by machine-timing. The bars 68 may be selected by energization of magnets 104, Fig. 5, instead of by the keys and this is the case when the product is being punched by the machine. The punch-operating plate 86 is extended at 112 to raise the bar 72 clear of the bail 70 after each punching operation whereupon the bar is drawn back by its spring 116 to open contact 74 and break circuit at 118 to the magnets 104. Driving-mechanism. The machine is operated by a continuously-running motor 160, Fig. 13, which rotates the counter-driving shaft 187, the operating shaft 200 for transmitting the tens from the first to the second counter, and the reset shaft 206, through one-cycle clutches controlled by magnets 172, 190, 202. Factor indicators; multiplicand selectors. The indicators are of the known Hollerith counter type but without transfer means and comprise numeral drums 210, Fig. 9, controlled in rotation from shaft 187 by clutch-shifting magnets 212. Geared with each drum of the multiplicand indicator through a pinion 218 is a fibre wheel 226 carrying two sets of radially arranged brushes 232, Fig. 16, co-operating with contact blocks 236 and strips 234 supported in stationary plates 228. There are nine radiating rows of blocks in each plate and each row comprises four blocks the strips also being four in number and occupying one half of the face, but the blocks and strips are reversely disposed in the two co-operating plates so that the blocks on, say, the lower half of one plate oppose strips on the lower half of the other plate. These wheels 226 and plates 228 constitute the multiplicand selectors and control the selection of the circuits determining the partial products, one set of blocks being connected with the tens group of product-determining devices and the other with the units group. Commutators. (1) Key timer; this consists of a series of contact blocks 254, Fig. 26, and a circular strip 256 bridged by a brush 262 carried by an arm fixed to shaft 184 (See Fig. 13). (2) Clutch timer; this consists of another arm on shaft 184 carrying a brush spanning concentric strips 266, 268, Fig. 27, of which strip 268 is broken on either side of home position 270. A clutch timer is used for each denomination in the multiplicand and multiplier circuits as shown in Fig. 30. Action when entering multiplicand. Depression of the first digit key, say 8, closes contacts 120, 120<a>, 122, Fig. 5, below the 8 key. As can be seen in Fig. 30, this establishes a circuit through line 280, contact 120 at 8, and wire 252 to key timer block 254 at 8. Contact 122 serves to establish a circuit also from wire 280 through the contacts below key 8, wire 282, armature latch magnet 94, counter clutch magnet 172, wire 284, clutch timer block 270 and brush 274, wire 286, plugboard 290, denomination-control or column contact 144, brush 150, strip 142, wire 298 to right of line. With clutch magnet 172 energized, shaft 184 begins to revolve and therefore to turn the commutators. With the departure of brush 274 from home position, clutch magnet 172 is de-energized to limit the rotation of the machine to one cycle. The latch magnet 94 is, however, maintained energized by a brush 285 and commutator until near the end of the cycle. During the rotation of shaft 184 the brush 262 wipes over the blocks 254 until block 8 is reached whereupon circuit is complete from wire 252, through the block and wire 304 and the left-hand indicator magnet 212 (See also Fig. 9), this particular magnet circuit being chosen by the cardfeeding escapement mechanism acting through brush 150 travelling along to bridge the successive column contacts 144 and strip 142. The digit 8 is thus set up on the multiplicand indicator and also on the selector (Fig. 16). The, keys for the remaining digits of the multiplicand are similarly depressed and the digits set up successively in the same manner. Action when entering multiplier. The card having arrived with the highest column space of the multiplier field under the row of punches, the first multiplier digit, say, 9 is entered by depression of the 9 key. This closes circuit from left of line, Fig. 30, through wire 280, contacts 120, 120a at 9, line 252<a>, master relay 312, resistance 320, switch magnet 316 rotary timer 264<a> the plugboard, column contact 144 and so to right of line. Magnet 316 consequently closes a contact 328 to maintain a circuit for one cycle through the closed contact 120<a> at 9. A circuit is also completed by the closure of all three contacts 120, 120a and 122 at 9 through the latch magnet 94, clutch magnet 172 and multiplier clutch timer block 270 to cause shaft 184 to make one revolution and enter the value 9 in the first drum of the multiplier indicators in the same manner as in the case of the multiplicand. The remaining digits of the multiplier are similarly entered and with each entering operation the multiplication proceeds. Multiplication process. As already stated this is carried out in accordance with the principle described in Specification 302,237 wherein the groups of contacts corresponding with the multiplicand digits are subjected to a code selection by projections on multiplier-responsive members. The contacts and the members are disposed in two groups (for the units and tens of the simple partial products) the contacts 372, Fig. 31, being arranged around the circumference of discs 341 or 342, Figs. 1 and 19, provided with teeth 360 spaced according to the requirements of the simple partial products and the code. When a multiplier digit is entered and a master relay 312 energized as described above, a corresponding disc 341, 342 in each of the two groups is displaced by means of pawls 346 to close the necessary circuits by the action of the teeth 360 upon bails 364 adapted to bear upon the contacts. These contacts are individually connected with the contact blocks 234, Fig. 16, on the multiplicand discs 226 already referred to. Fig. 31 shows diagrammatically the arrangement in so far as the multiplying of 8734 by 9 is concerned, the diagram showing, only the portion referring to the determination of the units values of the products. Thus with the 9 disc 342 displaced, circuit is completed at the a contact in the 8 line and in the code this is equivalent to 2 (9 x 8 = 72). Similarly for the products 9 x 7, 9 x 3, 9 x 4, are closed at 7, contacts a + c (= 3), at 3, a + b (= 7) and at 4, c (= 6). Translating code values into decimal values. Devices of the kind described in Specification 297,800 are employed to translate the combinational code values into decimal values for transmission to the product counters, translation and transmission taking place at each key depression during the entering of the multiplier. Assembling the partial products. The partial product digits are entered in their respective counters successively one step to the right and this is ensured by the following switch mechanism inserted between the translators and the counters. As shown in Fig. 33 the impulses from the translators 390 will flow normally through blades 431, contacts 432 and blades 433 to the four lowest coils 436 of the counter. When the second multiplier digit is entered a magnet 440 (see also Fig. 30) will be energized to raise all blades 431 to shift the impulses one step higher. Similar action occurs when the next digit is entered, the magnet 450 then shifting the blades 433 to direct the impulses a further step higher. It now remains