Patent GB-251991-A (GB)
Abstract: 251,991. Weiskopf, O. May 5, 1925, [Convention date]. Adding and subtracting apparatus, adapted for use with typewriters, has a lengthy counter divisible into smaller counters for computing in different columns, and laterally shiftable to bring these counters singly into operative position. A cross-computing counter is also provided. Attachments and connections to typewriters; differential-mechanism.-The vertically computing counter 57, Figs. 1 and 3. is actuated by a master pinion 29, Fig. 6, slidably keyed to a shaft 28 bevel-geared with a spur-wheel 20, Fig. 5a, driven differentially through a pin 19 by a slide 15, Fig. 4, controlled by a spring 10. Depression of a numeral key 2, Fig. 1, effects the descent of a corresponding plunger 11, a roller 11<a>, Fig. 9, on which enters a slot in the slide and by virtue of the inclination of the wall 16a of the slot forces the slide 15 to the right to a differential extent. This movement of the slide is also conveyed through another pin 19 and spur wheel 20, Fig. 5a, to a shaft 28 and master pinion actuating the cross-computing counter 59<1>, Fig. 3. Adjusting for addition or subtraction. The pins 19 for conveying the differential movements of the slide 15 to the spur wheels 20 are slidably mounted in an extension 18 of the slide, Figs. 4a and 5a, and are duplicated for each wheel so that the direction of the actuating movement imparted to this may be reversed by disabling say the lower pin and permitting the upper to be effective. To control the pins a spindle 22 having recesses disposed at 120‹ apart opposite the pins may be turned to permit one pin to spring forward into engagement with a slot in the wheel 20 and to withdraw the other. By giving the spindle a further rotation both pins may be disabled so as to render the corresponding counter inoperative. Thus by manipulation of the two spindles 22 the counters may add or subtract or be idle inde. pendently of each other. Adjusting for recording only.-The numeral keys 2 normally bear on rods 3, Fig. 1, carried by bars 4 pivotally attached to the aforesaid plungers 11. At their rear ends the bars 4 are mounted on a spindle 5 forming part of a stirrup frame 6 pivoted at 7 and drawn upwardly to the position shown in Fig. 1 by a spring 8. To disconnect the calculating-apparatus from the typewriter a key 6a may be depressed so as to lower the frame 6 and place the rods 3 out of reach of the keys 2. Selecting denomination.-The master pinions 29 of the two counters are shifted along their spindles 28 by means of slides 30, Figs. 6 and 10, connected by a rod 52. To one of the slides is attached a cord 39 secured to a pulley 38 adapted to be rotatably adjusted by a sector 35 forming part of a lever pivoted at 33. Above the other arm of this lever are ranged the denominationselecting keys! 40 their distances from the pivot 33 determining the amount of rotation given to the sector 35 and therefore the particular numeral wheels to be actuated. The slide is held in its adjusted position by the engagement with a pivotally mounted and spring-influenced rack 45 of a one-way pawl 41 pivoted to the slide. The descent of the plunger 11 continues to a slight extent after the differential movement of the slide 15 has ceased and this causes a rocking of the rack sufficient to disengage its tooth from the slide 30 so that this moves half a step to the right under the action of its spring 32 until stopped by contact of a finger 30<b> with the next rack tooth. The master pinion is thus disengaged from the numeral wheel so that the return stroke of the key may have no influence upon the counter. The rack is retained in its displaced position until the return stroke has been completed and for this purpose a one-way pawl 46 is pivoted on the rack and co-operates with a recess 49 :n the differential slide 15 so that when this is out of home position the pawl is free of the recess and by engaging with the slide will prevent restoration of the rack. When the return movement is ended and the pawl may again engage the recess the consequent restoration of the rack frees the finger 30<b> and permits the slide 30 to complete its step to the right. Splitting machine.-The counter 57 containing say fifty denominational places may be divided up into a number of separate counters each allocated to a different column. The counter as a whole tends to move to the left under spring action but is normally prevented by the engagement of one of a number of pins 62, Figs. 3 and 14, with a spring-controlled lever 53 mounted on the stationary casing and adapted to be depressed by a key 54 to free a pin 62 so that the counter may shift to the left until stopped by the next pin 62. The pins may be placed in any of a number of holes 61 so that the capacity and number of the various columnar counters may be varied at will.