Patent GB-913554-A (GB)
Title: Adding and subtracting machine
Inventor: ARVAI TIBOR
IPC: G06C7/08
Filed: 1959-05-15
Abstract: 913,554. Mechanical calculating-apparatus. SOC. DE MECANOGRAPHIE JAPY. May 15, 1959 [May 19, 1958], No. 16767/59. Class 106 (1).  In a ten-key keyboard calculating-machine, the actuator racks are carried by a carriage movable transversely with respect to the machine, the effective displacement of the racks is visible to the operator through a window and the racks carry printing bars whereby results can be printed on a paper tape. As described, each rack 10, Fig. 2, carries a stop 10a to limit movement during registration, toothing 10b to ensure alignment during printing, toothing 10c for latching the rack, toothing 10d for co-operation with the totalizer, legible figures 10e and printing figures 10f. The rack assembly is mounted in a carriage comprising side-plates 11, 12, toothing 21b on a plate 21 on the carriage serving for the step-by-step displacement of the carriage, which slides on a rod 22. Keyboard, Figs. 5, 6.-Each numeral key 25 is connected to a pivoted lever 31, the levers 31 being pivoted on a common shaft 32, and each lever bearing a lug 31b adapted to project, when a corresponding key is depressed through an aperture 30a in a lower horizontal plate 30 defining the keyboard. Depression of a numeral key also depresses a stirrup pivoted on the shaft 32, the stirrup having a lug 33b disposed opposite the escapement toothing 21b which co-operates with an escapement lever 35. The carriage being spring-urged to the left by a spring 43, Fig. 1, is thus allowed to move one step to the left on the depression and release of a numeral key 25. Depression of a sub-total or total key 27 or 28 moves a lever 39 transversely, Fig. 5, to act directly on the escapement lever 35, allowing the carriage to move fully to the left under the action of the spring 43. On depression of a numeral key, the stirrup pivoted on the rod 32 is lowered as described above to raise the end 36b of a lever 36 pivoted on a lug on the plate 30, to lift the latch 17 which is in engagement with the end 36b. The rack 10 associated therewith is thereby released and moves under the influence of a spring 15 until the stop 10a meets the lug 31b. When the key is released, the lug 31b is released and the latch 17 is effective to lock the rack in its displaced position. The depressed numeral appears in a window 59, Fig. 2, the successive numerals entered appearing sequentially in a window 181, Fig. 1, in the cover of the machine as the carriage steps to the left. The machine is operated by pulling forwardly and bringing back to its original position a crank 45 which is fixed to the main shaft 46. The crank 45 operates a pulley and cord arrangement (Fig. 3, not shown) effective to return the carriage to the right during the return stroke of the crank 45. Alignment for printing. Fig. 4.-The main shaft 46 carries a cam 60 co-operating with a roller 61 on a lever 62 articulated to an alignment rake 66 pivotable on a shaft 67. When the crank 45 is initially moved, the roller 61 mounts a boss 60b on the cam 60 and the teeth of the rake 66 project into the toothing 10b on the racks 10b which are thereby aligned. Printing from the racks 10 is carried out while rake 66 and toothing 10b are in engagement, whereafter the rake 66 releases the racks. Printing, Fig. 8.-Paper 68 from a supply reel passes over a roller 9 supported on a shaft 69 mounted in a frame 71 oscillatable about a fixed shaft 70. The main shaft 46 carries a cam 74 which supports a latch 75 opposite which is a cam roller 78 carried by a pivoted lever 79. The cam 74 also controls a further lever 82. During the initial movement of the main shaft 46, the lever 79 is rocked to permit the roller to be snapped towards the paper under action of spring 72. The lever 82 then causes the frame carrying the roller 9 to be reset against the springs 72. At the end of the initial movement of the crank 45, a transverse rod 51, Fig. 1, returns the racks to enter the number they contain into the totalizer. Totalizer, Figs. 12, 19.-The totalizer comprises two sets of wheels 93, 94 mounted on parallel shafts 91, 92, the sets 93, 94 mesh mutually in pairs and are alternatively engageable with the actuator racks 10. A detent 95 prevents unwanted rotation of the numeral wheels. One tooth of each wheel bears a transfer stud 98. The wheels 93 form an adding totalizer and the wheels 94 a subtracting totalizer. Transfer mechanism, Figs. 12, 19.-A set of transfer latches 99 pivoted on a shaft 100 are adapted to co-operate with the transfer studs 98 on the numeral wheels. Coupled with each latch 99 is a tongue 102, Fig. 12, having a bevelled end. When a stud 98 has rocked the latch 99, the latter comes to engage its notch 99e on the heel of a catch 103 to set the corresponding transfer mechanism. A transfer drum comprises a shaft 106 driven by gearing from the main shaft 46 to perform two revolutions when the crank 45 is moved out and back. The shaft 106 carries helically-arranged fingers 111 0 , 111 1 , &c., Figs. 1 and 2, constituted by the points of plates threaded on grooves of a sleeve 112 fast with the shaft 106. Transfer is effected during the return movement of the crank 45, when, since the totalizer is disengaged from the actuator racks, the set tongues 102 are in the path of travel of the fingers 111 1 , 111 2 , &c., which are displaced sideways by the bevelled ends of the set tongues 102 to engage in a tooth space in the numeral wheel of next higher order and step it on by one tooth. Articulated on a shaft 105 are two stirrups 115, 116, the lower edges of which are adapted to de-set the transfer latches 99, a notch on the stirrup 116 preventing de-setting of the first latch which is to the right of the units wheel. A further stirrup 120 is pivotable on the shaft 88 on which the totalizer is rockable, and this stirrup is effective during the second revolution of the transfer sleeve 112 to transfer to the first right-hand latch if the sign of the balance in the totalizer has been changed. During the return movement of the crank 45, the stirrup 116 disengages all the transfer latches except the first which, in the following revolution of the sleeve 112 permits the units wheel to be advanced by the finger 111 0 . Subsequently the stirrup 115 returns all the latches set in the second rotation to their de-set positions. Interchanging totalizer sets, Fig. 17.-As shown, the totalizer wheels 93, on the shaft 91 are adapted to engage the actuator racks. To interchange the totalizer sets, as for subtraction, a lever 121 is manually rocked in the direction of the arrow f 13 . A cam roller 125 therefore mounts a boss 121c to rock a lever 126. The transfer latches are disengaged, and bearing- plates 89 carry out a half-revolution, the roller 125 falling in a recess 121b. The transfer latches are then freed. Totalling operation, Fig. 20.-When a total or sub-total key 27 or 28 is depressed the carriage is released and at the end of its travel to the left an extension on the carriage contacts an extension 133a on a pivoted lever 133 to arrest the carriage. When the key is released, the extension 133a is withdrawn and the carriage moves slightly to the left to a position in which each rack is aligned with one of the pairs of totalizer wheels. In this slight movement, a trigger 137 is rocked to release a hammer 139 which moves under the action of a spring 140 to meet a rod 132, thereby lifting all the latches 17 to release the actuators which are differentially displaced according to the totalizer registration. The crank 45 is then operated and the required total is printed. Correction operation.-If an incorrect number is seen to have been set in the racks, depression of a correction key prevents its being entered in the totalizer when the crank 45 is operated.