Patent GB-464676-A (GB)
Abstract: 464,676. Calculating-apparatus. TOMLINSON, A. V. (Soc. Anon. Officine Galileo) July 18, 1935, No. 16186. [A Specification was,laid open to inspection under Sect. 91 of the Acts, Dec. 5, 1935.] [Class 106 (i)] Adding and subtracting apparatus.-In a machine in which a digit equal to or greater than 5 is added by subtracting its complement with respect to 10 an actuating mechanism is provided comprising members adapted to be coupled to an operating member so as to move differentially in one direction or the other in accordance with the digits set up, each actuating member being connected to one element of a differential gear, a second member of which forms the totalizer actuating rack and the third element of which forms a connection to the next lower denomination and is adapted to be coupled to the operating member under the control of the keys for setting a digit 5 or over, and under the control of a position checking member, settable to a position depending on the digit set up in the lower denomination and co-operating, before the actuation of the numeral wheels is effected, with a projection on the numeral wheel of the lower denomination. In the machine shown in Fig. 8, each bank of keys 7 is associated with a T-shaped lever 5<1> the depression of a key numbered 1 to 4 rocks the corresponding lever 51 in one direction while depression of a key numbered 5 to 9 rocks the lever in the opposite direction. This movement is imparted to a corresponding slide 5 having a number of differentially positioned projections 1b ... 4b and -1b ... -5b any one of which projections, according to the key depressed, is brought into alignment with similarly numbered crossbars of a pantograph or proportional frame. Fig. 9, articulated on pivots O, O<1>. After the item has been set up the frame carrying the slides 5 is lowered by means not shown so as to couple the appropriate cross-bars to the elements 1 of the actuating means. Each element 1 carries a pinion x meshing with a totalizer actuating rack 3 and a tens rack 2 that is adapted to be coupled to a rack 20 associated with the cross-bar -2b of the next lower denomination. The tens rack is normally stationary for the digits 1 to 4 but is coupled to the rack 20 for the digits 5 to 9 by means of a pawl 19 pivoted on the rack 2, and provided with an elongated slot engaging a pin 42 on a lever 18. The lever 18 carries pins 28, 29 either of which can engage a slot in a slide 25 to serve as a pivot for the lever. The normal position of the slide, is shown in Fig. 5a<2> with the control springs 27 for the levers 18 under compression and the springs 26 expanded so that the pin 42 maintains the pawl out of engagement with the rack 20. A move ment of any slide 25 to the right brings the pin 28 into a slot of the slide to act as a pivot thereby, under the action of the springs, lowering the pin 42 to cause the paw 19 to engage the rack 20 The displacement of a slide may be effected, by means not shown, by the setting up of any of the digits 5 to 9 in the next lower denomination. The pawl carrying lever 18 is subjected to a further control in dependence upon the amount already registered on the totalizer numeral wheels 4. The mechanism for this purpose comprises, for each denomination a slide 6, Figs. 5a<1> and 8, which is connected by a pin- and-slot arrangement with a slide 5 so as to move therewith in order to bring one or other of the pins 23, 24 into engagement with a notch of a bell-crank lever 8, and into alignment with one of a set of differential notches 1 ... 4 or -1 ... -5 of a plate 22. After this setting operation and, during the time that the slides 5 are lowered to couple the crossbars of the pantograph members to the actuators 1 the plates 22 are lowered to the position A for additive operations or raised to the position S for subtractive operations thereby imparting a rocking movement to the levers 8. To each lever 8 is connected one end of a link 9, forming a position checking member, the other end of which is connected to a link 10 pivoted at its upper end to an arm 11 on a shaft 45. The movement of the lever 8 depends on the digit set up and imparts a proportional displacement to the corresponding link 9. If during this displacement a projection o<1> on the link 9 meets or moves past a projection o on the numeral wheel the link 9 is depressed to rock the arm 11 against the action of its spring 59 thereby depressing a depending link 12 on the end of the arm 11. The lower end of the link encounters a bellcrank lever 17 and pushes a slide 30 to the right so that a roller thereon meets a projection on a corresponding cam disc 21 and effects the depression of the lever 18 to raise or lower the pawl 19 depending on which of the pivots is active. The cam discs by means not shown, receive a quarter revolution during the operative movement of the plates 22. If the lowering of a link 12 occurs at the instant when its cam disc 21 completes its movement it cannot act on the bell-crank lever 17 as a hammer-shaped lever 14, through its cooperation with a cam projection, meets a projection on the link 12 and swings it clockwise. The swinging movement is imparted to an arm 13 which pushes a link 15 so as to straighten a pair of toggle levers 16 that carry pins 44 located in holes in adjacent levers 18. By this arrangement the levers 18 can be connected together to vary the position of the pawls 19 and a connection is also provided between the highest and lowest denominational levers 18 as shown in Fig. 5f. The action of the mechanism will be understood by -reference to the numerical examples set forth in the Specification. Multiplying and dividing apparratus.-For multiplication the multiplicand is set up on the keyboard 7 and the multiplier digits are set successively by depressing the appropriate key levers 38. After the preliminary settings, as for addition, the pantograph 'is moved a number of unitary steps in accordance with the multiplier digit. The mechanism (not shown), operating the cams 21 is operativelyconnected with the pantograph so as to carry out a quarter revolution for each unitary step of movement so that the checking operation, by the previously set links 9, is prepared during each step for movement for the next succeeding step. To ensure the correct setting of the lever 18 for the successive steps the lever 18 of one denomination is connected to that of the next higher denomination by means of a lever 36 pivoted to the respective levers at points 60, 61. The lever 36 assumes one or other full line position if one lever 18 is up and the other down or the dotted line position of both levers 18 are in the same position. In this latter position the end of the lever 36 forms a stop for an angle lever 33 pivoted on the arm 13 so that when the arm 13 is swung clockwise a hooked lever 34 pivoted on the slide 30 is raised into the path of a pin 35 on the corresponding cam disc 21 so that on the rotation of the cam disc the slide is pulled to the right, Fig. 5h, to prepare for the next setting of the lever 18. For multiplication the numeral wheels are mounted in a displaceable carriage. In division operations the dividend is set up on the numeral wheels and the divisor on the keyboard ; the pantograph is moved to the full extent of its travel and the numeral wheels engaged. During the return movement the lever 18 of the lowest denomination is lowered bv its connection with the lever 18 of the highest denomination. When this occurs a lever 54, Fig. 7, is rocked and a pawl 53 is moved into engagement with teeth of a rack 55 rigidly connected to one of the cross-bars of the pantograph so as to arrest the movement of the frame prior to that step which would cause the numeral wheels to pass to the negative numeration. Division could also be performed by setting up the dividend on the negative numeration and adding the divisor set up in the machine.