JPS6418020A - Shielding apparatus for water meter - Google Patents

Abstract

PURPOSE:To enable the transmission of rotation of an impeller, generated with an inflow into a measuring section accurately to a receiving section, by shielding a mechanism rotating in a non-contact manner with a permanent magnet fastened on a rotating shaft leading from one end of a water meter gear mechanism. CONSTITUTION:With the generation of an inflow 6 into a measuring section 5 of a water meter body 1, an impeller 7 is rotated to transmit the rotation thereof to an integration instruction mechanism 9 via a gear mechanism 8. Permanent magnets 11 fastened on a rotating shaft 10 leading from one end of the gear mechanism through a water shielding glass plate 12 are energized through two reed switches 13 sealed and imbedded into the tip thereof 11 to be magnetized in opposite polarity to each other. Then, the magnets are covered 15 securely 18 with a laminated layer of a magnet sheet 29 made of magnetically shielding material, a synthetic resin 27, an amorphous metal 28 and the synthetic resin 27. with the rotation of the impeller 7 caused by the inflow 6 into the measuring section 5, the positions of the permanent magnets on the rotating shaft 10 of the mechanism 8 changes. Then, two switches 13 are opened or closed alternately at each half of rotation to generate an electrical signal to display 26 by integration on a receiver 3 via a transmission line 16.