Patent GB-191400829-A (GB)
Title: Improvements in Adding and Subtracting Apparatus.
Inventor: DICKER STANLEY GORDON SINCLAIR
Filed: 1914-01-12
Granted: 1915-02-12
Abstract: 829. Dicker, S. G. S., [Heath, W. R.]. Jan. 12. Adding and subtracting apparatus; transfer mechanism. - In the totalizing - counters of adding and subtracting apparatus adapted to be attached to a typewriter and provided with totalindicating drums bearing two sets of oppositely - arranged numerals and an automatically-operated shutter bearing sight-openings distinguished by positive and negative signs, the whole designed for registering results that may pass through zero value, the total drums and actuateing-wheels are loose on the shaft 12, each set comprising a spur-wheel 13, a single-toothed disk 14, and a total drum 15 secured together. At each end of the shaft are mounted arms 17, 19 carrying the apertured shutter 22, teeth 21 being formed on the upper part of the arm 19 and adapted to engage a sector 37 secured to a shaft 25. The transfer gear devices are mounted on the shaft 25 and comprise differential bevel-wheels 26, 27 connected by a pinion 30 mounted in a driving- wheel 28. Secured to each wheel 27 is a wheel 29, gearing with a wheel 13. Adjacent to each wheel 30, except in the unit sets, is a loose Geneva-wheel 31 which is engaged by a single-toothed wheel 14 and has secured thereto a bevel-wheel 32. Pinions 35, carried by brackets on the framing, are provided to connect the wheels 32 to wheels 33 secured to the wheels 26. The hundreds-wheel 31 is carried by the hub 36 of the sector 37, the movement of this sector being limited by a pin 38, Figs. 1 and 4. On the hub 40 of the units-wheel 26 are secured a toothed segment 41 and a differential bevel-wheel 42, connected by a pinion 45 to a similar wheel 39 pinned to the shaft 25, the pinion 45 being carried by a plate 43 loose on the shaft and provided with an arm 44. Carried in the top part of the casing are telescopic shafts 46, 47, 48, each bearing a broad pinion 49 engaging the wheels 28 and normally locked by projections carried by an alining-bar 50, the pinions being broad enough to remain in engagement with their wheels when freed from the alining-bar. Loose on the shaft 46 is an arm 51 always engaged by the alining-bar projections and provided at the lower end with diverging cam-projections 52, Fig. 7, between which the arm 44 engages. When moved into the operative position, the sector 41 is engaged by the parallel portions of the cams 52. In the operation of subtraction, the movement through zero from positive to negative causes a rotation of the hundreds single-toothed wheel 14, which moves the shutter through the wheel 31 and the sector 37, to obscure the positive and show the negative readings. The shaft 25, rotated by the sector 37, drives the bevel-wheel 39 and, the wheel 42 being locked, moves the pinion 45 and thus the finger 44 into engagement with one of the cam-surfaces 52, so that when the telescopic shafts are returned to their initial position, the wheel 42 is actuated bv the camsurfaces to advance the units-wheel through one division to give the correct result. In a modification, the part 51 is not moved in agreement with the shafts 46 &c., but independently by means of a projecting piece: or it may be arranged to remain stationary in the right-hand position, the gearing being then adapted to deal with a simultaneous actuation of the unitswheel and a transfer of the necessary unit movement thereto.