Retarding magnet assembly for electricity meter

Abstract

A retarding magnet assembly includes magnets configured to apply a constant drag on the rotating disk of an electromechanical electricity meter. The assembly includes upper and lower keepers secured to opposing extensions of the meter frame. A spacer is secured, at a first end, to the upper keeper, and a non-magnetic flexure spring is secured to a second end of the spacer. A pair of upper magnets are secured to the flexure spring member at opposing ends. A pair of lower magnets are secured to the lower keeper at opposing ends. The meter rotating disk extends between the upper and lower magnets. The equilibrium point of the flexure spring changes, depending on strength of the upper magnets and their consequent attraction to the upper keeper. Thus, if the upper magnets becomes stronger due to a temperature change, the attraction of the upper magnets to the upper keeper increases, and the upper magnets move closer to the upper keeper. Since the upper keeper is mounted rigidly with respect to the disk, this motion results in the upper magnets moving away from the disk, which in turn reduces the strength of the magnetic forces from the upper magnets on the disk. By increasing the distance between the upper magnets and the disk when the magnetic strength of the upper magnets increases, a substantially constant drag is exerted on the disk. Similarly, if the upper magnets decrease in strength, the upper magnets move away from the upper keeper, reducing the distance between the upper magnets and the disk.

Dependencies are inferred from the claim text.