Patent ID: 6259797
Filing Date: 2001-07-10
Classification: H04R

Abstract:
A metal base assembly for a speaker that combines with a magnetic circuit to produce a fluctuating magnetic field which drives an acoustic diaphragm into vibration to produce a warning alarm, comprising:a top pad, wherein the top pad is a circular metallic disk having a hole in the middle and a plurality of positioning holes around its periphery;a middle pad connected to the top pad, wherein the middle pad is a circular metallic disk having a hole in the middle and a plurality of positioning holes around its periphery that matches the set of positioning holes in the top pad;a bottom plate connected to the middle pad, wherein the bottom plate is a circular metallic disk having a plurality of positioning holes that matches the positioning holes in the middle pad;a plurality of positioning rivets that pass through the positioning holes of the bottom plate and through the positioning holes of the middle pad, and terminate inside the positioning holes of the top pad, such that the top pad, the middle pad and the bottom plate together form a metal base having a recess cavity, which recess cavity results from the combination of the central holes of the top pad and the middle pad;a magnetic plate inside the recess cavity for generating a fluctuating magnetic field; anda metal plate above the magnetic plate inside the recess cavity.