Electrical switch for detecting positions of an automatic transmission of an automobile

摘要

An electrical rotary switch in use with an automatic transmission for detecting the operative position of the transmission and controlling an electric circuit associated with the positions of the transmission. The switch comprises a switch casing composed of a base plate and a cover plate each formed of an electrically insulating material and provided in its interior surface with a plurality of fixed contacts. Supported between the base plate and the cover plate is an actuator which is rotatable about a rotation axis in response to the changing positions of the automatic transmission. The actuator has a coupling end to be interlocked with a control output shaft of the transmission which is provided to rotate in synchronism with changing positions of the transmission. The actuator has first and second opposed faces each confronting the interior surface of each one of the base plate and the cover plate, and carries first and second movable contacts respectively on the first and second faces for electrical conduction between selective ones of the fixed contacts on the individual plates depending upon a particular angular position of the actuator about the rotation axis. Also formed on the switch casing is a terminal assembly comprising a plurality of terminal pins leading from the individual fixed contacts for connection with the external electric circuits. The movable contacts are carried in slots in the actuator. A third moveable contact is used to energize the starter circuit when the park and neutral positions of the transmission are detected.