Rotary switch including cam operated flexible contacts

Abstract

A rotary switch includes a plurality of switching terminals exposed within a chamber in a housing. A fixed planar contact member, having a plurality of spring contact arms, is mounted in the chamber above the terminals. Each of the contact arms is movable out of the plane of the contact member to contact an associated one of the terminals. Each of the contact arms includes a cam follower, at least two of the cam followers being equidistant from the center of the contact member. The cam followers are operatively engaged, in a predetermined sequence, by camming elements extending axially from the bottom surface of a rotor mounted in the chamber above the contact member. The equidistant cam followers are engaged by camming elements that are spaced from the center of the rotor by a distance equal to the distance separating the equidistant cam followers from the center of the contact member. Thus, at least two contact arms are actuated by camming elements sharing a common radius, thereby allowing the optimum use of space. The contact member is fixed in the chamber by a set of asymmetrical tabs that are received in slots in the chamber wall, thereby preventing an inadvertent erroneous orientation of the contact member during assembly.