ES55915U - Plumier with device to add and subtract (Machine-translation by Google Translate, not legally binding) - Google Patents

Abstract

Plumier with addition and subtraction device, characterized by being constituted by a cassette of suitable shape and dimensions in which one of its faces, preferably the lid, is hollow and contains in its interior a plurality of disks, in equal number to the indicated by the order of the upper unit provided maximum for the sum or minuendo, which, equipped on its edge with two projections with their corresponding escape and arranged in convenient order and susceptible to rotation with a tendency to be immobilized in certain positions under the action of appropriate elements, have correlatively numbered the periphery of its upper face with the figures of the numbering system that are adopted corresponding to each disc in each of the aforementioned figures, visible successively through a window-box opened in the cover for each disk, two holes facing circular openings in the lid, which determine each plate attached to the cover by a small bridge, which at the same time acts as a stop when rotating the disc by means of a stylus engageable in the recesses, the lower face of each disk being shaped as a gear wheel, of smaller diameter than that and with so many teeth as figures have the numbering system and a projection next to the edge by which each disc links with another gear of equal number of teeth, mounted between each two consecutive discs, which in turn links with the bottom of the next disc and remains subject to the action of a lever actuated by the projections of the previous disc, the circular openings of the cover on both edges having corresponding numbers, in reverse order and from the stop-bridges, formed by the figures of the numbering system, which are used, respectively, in the addition and subtraction operations to rotate the corresponding disk in one or the other direction. (Machine-translation by Google Translate, not legally binding)