GB166011A - Improvements in indicating devices for measuring apparatus - Google Patents

Abstract

166,011. Gros, P. M. F. Dugit-, (known as Dugit, M.). May 13, 1920. Dials and scales; index hands and pointers; multiple-indication apparatus.-Consists in a uniformly graduated scale carried at the edge of a radial slot in a stationary disc and a relatively rotatable disc mounted on the same axis upon which is marked a spiral or series of spirals representing the polar co-ordinates of the variable which is to be measured, the reading at the intersection of the scale and spiral or one of the spirals giving the result. Figs. 2 and 3 show the application to an aneroid barometer, a rod 3 fixed to the diaphragm 5 acts upon a finger 6 secured to a shaft 7 and is thereby oscillated and through a second finger 8 engaging the forked end 9 of a toothed sector 12 actuates a pinion 13 to the spindle of which is keyed the disc 15 marked with a curve C<1> representing the atmospheric pressure as a function of the angular displacement of the disc. A cover disc 16 arranged above the disc 15 is provided with a radial slot 17 and uniform scale 18. To compensate for variations in temperature a series of spirals C<0>, C<1>, C<2>, Fig. 7, corresponding to the various temperatures are traced on the disc 15; corresponding curves G‹, G<1>, G<2> may also be provided for giving the altitude for the same temperatures, an altitude scale 23 being arranged on an adjustable frame 24. The terminal elements of an altimeter as shown in Fig. 8 comprise in addition to the main spiral C several auxiliary spirals and a corresponding scale for reading off the units of inferior order. The main and auxiliary scales F, f are provided with means for enabling the zero of the scale to be adjusted comprising a screw 38 rotatable in the framework and engaging a flange on the scale bearing members which are slidable in slots in the framework. In a modification Fig. 11 only one auxiliary curve c is provided the reading of inferior units being effected by means of this spiral on several auxiliary scales f<0>, f<1>, &c.