Patent GB-298260-A (GB)
Abstract: 298,260. Debenham, E. R., Rowley, C. D., and Isherwood, H. July 6, 1927. Multiplying-apparatus.-A single-bank multiplying machine has a number of groups of selector-mechanisms corresponding with the maximum number of digits in the first factor, and the digits of this factor are entered in the groups successively by depression of the respective keys. The completion of the partial product selection and the actuation of the machine are then effected by the entering of the digits of the second factor, each key operation selecting the particular partial product and setting up tens and units stops determining the movement of totalizer actuating-racks. Two constructions are described, the first having a maximum capacity of 99 x 999 and the other a capacity for dealing with factors each of four digits. First construction; key actions. Ten keys 21, Figs. 1, 3, and 4, are guided at their lower ends by a slidable bar 24 adapted at each key depression when entering the first factor to move one step to the right so that the key stems successively stand above the ends of three sets of levers 51a, 51<b>, and 54. The bar 24 carries a pivoted stepped plate 25 adapted to engage a stop 30 and is urged to the right by a blade spring 40 fixed to a shaft 38. Depression of a key lowers an universal bail 36 so as to bring a pawl 34 carried by it beneath the next lower step on the plate. When the key is released, therefore, the rise of the bail due to the spring 39 rocks the plate upwards to allow the bar to slide one step to the right. After two steps of movement a projection 41 from the bar allows the spring blade 40 to enter a notch 42 in the bail 36 so that at each subsequent key depression, that is, when entering the digits of the second factor, the shaft 38 is also rocked in order to effect certain operations in the machine. Selection of partial products. Disposed in rear of the keyboard are two groups of vertical rods 70, each group comprising ten rows of ten rods. When the key corresponding with the first or tens digit of the first factor is depressed one of the bell-crank levers 51<a> is rocked to effect a forward displacement of a bar 66 serving as a guide for the lower ends of the corresponding row of rods comprised in the left-hand group. Entering the second digit of the first factor similarly produces a displacement of a row in the right-hand or units group through the second set of levers 51b. The rods thus swung have their lower ends brought immediately over knife blades 80 running across the machine and mounted for parallel motion. If the key denoting the first digit of the second factor is now operated, it rocks a lever 54 to raise the corresponding knife blade and thus elevate a particular rod 70 in each of the two groups. The rods at their upper ends co-operate with two of a series of lever-like plates 90 hinged at their rear edges and normally resting at their front edges on lugs 93. Each plate has a value as indicated in Fig. 6, and this value is set up by means of a stop pin in one of four rods 100 - - 103, Fig. 9, the stop-pins resting upon or penetrating the warious plates according to their positions. Each of the two groups of plates has an upper or tens section and a lower or units section, and when a rod 70 is raised a shoulder 75 thereon raises a plate corresponding with the units figure of the partial product while the end 76 of the rod raises a plate in the upper section to set up the tens figure of the product. Collecting and adding the partial products. The totalizing counter 146, Fig. 1, is mounted in a rocking and transversely-slidable frame 140 pivoted at 151. The numeral wheels are driven through the gearing shown from spur wheels 147 adapted to engage sliding racks 120 - - 124, Fig. 2. When the stop-pins have been set up as described above the racks are advanced to engage them by arms 192 loose on a spindle 191, but rocked thereby through resilient devices 199, 200. The racks having thus been differentially set the counter is lowered into engagement and the racks returned to enter the product of the first factor and one digit of the second factor. The timing control of the counter is effected through arm 152, lever 176, and link 175 from the shaft 38 rocked by the key when entering this digit. In order to add the units of the first partial product to the tens of the other the rack 121 for actuating the central numeral wheel of the three wheels concerned in receiving the partial products due to any one digit of the second factor, co-operates with the two rows of pins in question, namely 100, 101, so as to move a distance equivalent to the sum of the values appertaining to the pins set up in these rows. For this purpose the pins are spaced at double the distances of those in the other rows and the rack carries a two-armed lever 128 adapted to engage the pins in the respective rows 100, 101. As each key is depressed during the second-factor entering operation the counter is shifted one place to the -left to receive the intermediate products in their correct denominational positions by means of a rack 153 on the counter frame and a crank pin on a shaft 212 driven from the shaft 173. Main operating-shaft. A spring drum 174, Fig. 2, on the main shaft 173 is wound up by the resetting operation and the shaft is permitted to turn through two half-revolutions at each key operation during the entering of the second factor. To this end a pair of arms 171, 172, Fig. 1, fast on the key-rocked shaft 38 alternately release and stop a pawl 179 fast on the shaft 173. A spring- controlled pivoted plate 180 is also provided to prevent a too rapid oscillation of the escapement arms, the plate having a pin 181 to take under and hold the arm 172 until the plate is deflected by the arrival of the pawl 179. Transfer-mechanism. When the counter has reached its furthest position to the left any transfers to the three highest wheels are permitted by allowing one or more steps of movement to the rack 122 and also to the additional or transfer racks 123, 124; which normally are stopped in zero position by a pin 115 or 116, Fig. 9. When the counter makes its final step to the left it carries with it a stop plate 132 so as to position apertures therein opposite the ends of the three racks to allow these to travel one or more steps to the rear to carry out the corresponding transfers. The control of the racks for this purpose is effected by stepped cams on the lower wheels 147, the steps of which form abutments for lugs 131 fast to the next higher racks. Resetting-arrangements. The displaced parts of the machine are restored by a single rotation of a resetting-shaft 220, Fig. 1, interlocked with the keys by means of a notched disc co-operating with an arm 43 of the universal bail 36. The counter elements tend to return to zero by the action of springs in drums integral with the receiving wheels 147, but are restrained by a common detent plate 163 disengaged from the wheels 147 by the movement of the counter into actuating engagement due to a pin 166 meeting a normally stationary rod 19. In the re-setting operation this rod is raised by a cam on shaft 220 to free the wheels to allow them to return to zero position as determined by a pin 167 and stop 168. Another rod connected with rod 19 functions to disengage the traversing shaft 212 from the rack 153 so that the counter frame can return to normal position under the influence of a spring blade. Another cam on the resetting- shaft bears on a lever adapted to rock a bail 233 and restore the sliding bars 66. An extension of the bail serves through a bell-crank 238, Fig. 3, to replace the guide-bar 24 to return the key stems to their left-hand positions. A further cam on shaft 220 rocks a bail 241 to return any racks that have additionally moved due to transfer to normal position, whereupon the stop-plate 132 is free to return also. A gear-wheel on the shaft 220 drives a pinion on the spring-drum 174 to rewind the spring. Second construction. This differs from the first construction not only as to its capacity but also in regard to various details and portions of the machine. As this form of machine has to deal with five-digit factors there are five groups of rods 70 and corresponding plates 90, and these are selected and actuated as in the first construction in order to raise pins disposed in ten rows as seen in Fig. 29. Key action. The keys set up the rods 70 in the different groups by acting successively upon rods 22, Fig. 19, connected at their lower ends to the levers 51 and bent and spread fan-wise. The rods 22 are guided at their upper ends by a bar 24a slid towards the rear of the machine at each key actuation by escapement mechanism similar to that employed in the first construction, the various rods 22 coming one after the other into functioning position with respect to the keys to cause the setting-up of the rods 70 in the several denominational groups. An extra key 21<x> is provided in this form of machine for the purpose of swinging the rods 22 without affecting the rods 70 in order to bring the second factor 22f into action after the digits of a first factor of less than five digits have been entered, thus obviating the use of a nought key and the consequent display of noughts to the left in the product. Adding the partial products. The stop-pins raised by the plates 90, as in the first construction, are disposed in ten rows 300 - - 309, Fig. 29, and co-operating with these are six sliding racks for actuating the counter during their forward strokes. The racks have forwardly extending feeler arms 310 - - 315, and of these the intermediate arms 311 - - 314 are adapted to advance to an extent depending upon the sum of the values set up in the row on either side. For this purpose the feeler arm, say 311, Fig. 32a, has a bent end, so that when it meets a set stop-pin in row 302 it is deflected into engagement with a rack 293 formed