GB656601A - - Google Patents

Abstract

656,601. Calculating-apparatus. HERZSTARK, C. Dec. 31, 1947, No. 35027. Convention date, April 12, 1939. [Class 106 (i)] A compact calculatng machine with a single stepped-toothed drum and transfer and totalizing elements arranged in a circle round it, is characterised in that the entering wheels and tens transfer wheels are provided with less than ten teeth, preferably five, and a reduction drive is provided between the entering wheels and the number wheels so that the number wheels make a tenth of a revolution for each tooth of the stepped drum. Pinions 4 are slidably adjusted by arms 6, justified by spring-pressed balls 9 in notches 8, so that their positions on their respective splined shafts 5 vary in accordance with the digits in a number being set up and correspond to the number of teeth on a stepped drum 3, around which the shafts are arranged, with which the pinions will engage when the drum is rotated by a cranked handle 2, pin-wheels 10 on the shafts 5 then engaging pinions 11, justified by spring-pressed balls c and rigid with decade cams 12 and numeral drums 13 which are rotatable on pins 14 inserted in radial slots in a rotatably journalled body 16. When a numeral drum 13 passes from 9 to 0, its cam 12 depresses a spindle 20<SP>1</SP>, justified by a spring in grooves 29, and lowers a pinion 18, on the shaft 5 corresponding to the next higher denomination, into the path of a tooth 22 on a plate 24, rotatable on the shaft 1 of the drum 3 by which it is driven through pin and slot 27, and subsequently as the turn of the handle 2 is completed, the pinion 18 is advanced one tooth and a sloping lug 25 lifts the pinion 18 and spindle 20<SP>1</SP> free from the path of the tooth 22 to a position where a pinion 17 is locked against rotation by a plate 26. To spread the driving and transfer operations over as much of a complete turn of the handle 2 as possible, reduction gearing is introduced as, for example, by forming the pinions 11 each with ten teeth and the pin wheels 10 and pinions 4 each with five teeth. For strength the teeth of the drum and of the entering and transfer pinions are formed asymmetrically and resemble ratchet teeth, the drum rotating in one direction only.