Variable resistor

Abstract

A variable resistor whose resistance is adjustable by rotating a rotor on an insulating substrate having an arcuate resistive element. The rotor is formed of an insulating resin and includes an inner skirt and an outer skirt extending from a bottom surface thereof. The inner skirt contacts the upper surface of the insulating substrate inside the arcuate resistive element. A metallic slider is integrated with the rotor by insert molding. The slider comprises a base formed of a metal plate folded at least into two, and arms having contacts at the tips thereof for slidably contacting the resistive element on the insulating substrate. The arms are folded along lines which are parallel to a line extending from the center of the base to the contacts of the arms to cause the contacts to project toward the insulating substrate. One of the metal plates forming the base cooperates with the inner and outer skirts of the rotor to seal a space accommodating the resistive element and the arms of the slider. External electrodes formed on the insulating substrate, with each of them connected with the resistive element, comprises a lower layer of silver, an intermediate layer of nickel or a nickel alloy, and an upper layer of tin or a tin-lead alloy.

Dependencies are inferred from the claim text.