Patent ID: 6040757
Filing Date: 2000-03-21
Classification: H01C

Abstract:
A variable resistor comprising:a case;a rotatable rotor accommodated in the case;a shaft projecting from an upper surface of the case being engaged with the rotor;a resistance substrate having a collector electrode formed on the central portion of the surface thereof and a circular resistor formed concentrically on the periphery of the collector electrode being accommodated in the case; anda slider having a first contact portion contacting the collector electrode and a second contact portion slidably contacting the resistor being provided with the rotor, whereinthe case includes a stepped surface on an upper surface of the case, the stepped surface supporting the peripheral surface and the bottom surface of an O ring,the shaft includes a boss portion contacting the inner circumference of the O ring and an operating portion projecting from the upper surface of the case and covering the stepped surface of the case,the inner and outer circumferences of the O ring are in compressed contact with the stepped surface of the case and the boss portion of the shaft, anda gap is provided between either upper or lower end surface of the O ring and the stepped surface and the bottom surface of the operating portion.