GB140765A - Electric meters for alternating currents - Google Patents

Abstract

140,765. Azienda Elettrica Municipale della citta di Milano. March 26, 1919, [Convention date]. Induction motor meters.-In an alternating-current motor meter of the induction type, the armature Z, Fig. 3<A>, counting-mechanism, and brake magnet B are mounted on a frame Q so as to be removable as a whole from the case S<0>, Fig. 1<A>, carrying the magnetic system. The central core M<A> of the series magnet, or a soft-iron pole-piece attached thereto, is adjustable for phase displacement. On the outer arms M are mounted shortcircuited coils S<1>, S<R>. The shunt magnet Nv is formed of laminations of soft iron alloyed with silicon, and has polar extensions N to which is attached a brass cross-piece T. An iron rod S is slidably mounted on the cross-piece T to overcome starting friction. An iron piece F, bent twice at right-angles, is attached at one end to the core and attracts at its free end an iron screw I, Fig. 3<A>, on the armature spindle P. This spindle rests at its lower end on a stone bearing-block in a footpiece P<1> held by a spring m. The upper end of the spindle P is provided with a stone bearing Y, Fig. 3<B>, having a central hole which engages a fixed pin. The brake magnet B is adjustable about a pivot h by means of a screw x, Fig. 3<A>