GB881200A - Improvements in or relating to counting mechanisms - Google Patents

Abstract

881,200. Zeroizing-mechanisms. ENGLISH NUMBERING MACHINES Ltd. April 1, 1960, No. 11560/60. Class 106 (1). In a counter in which the numeral wheels carry heart-shaped zeroizing cams, the zeroizing pawls are resiliently connected to a pawl-operating member so that after zeroizing; the disengaged transfer pinions are re-engaged while the pawls remain in contact with the cams, the numeral wheels being thus retained against undesired rotation after they have been zeroized. As described, a counter has four numeral wheels 1-4 driven by a driving pinion 7 and transfer pinions 18, the pinions being mounted on a shaft 8 carried on a carrier 22. The numeral wheels carry cams 21 adapted to be engaged by pawls 34 resiliently connected to pawl-operating members 29, the pawls and 34 pawl operating members 29 being formed as a unit 24 which may be of nylon. For zeroizing, the unit 24 is rotated clockwise (Figs. 3 and 5), a friction coupling in the form of a spring 38 causing the pinion carrier 22 to disengage the transfer and driving pinions. The pawls 34 bend due to their resiliency until they contact the operating members 29, whereupon continued clockwise rotation of the carrier 22 causes the wheels to be zeroized. During the anticlockwise return movement of the pawl unit 24, the pinions 7, 18 (Figs. 3 and 5) re-engage with the numeral wheel driving gears while the pawls 34 still remain in contact with the cams 21 thereby maintaining the numeral wheels against rotation.