Patent ID: 6946815

Claim:
A switch for a variable-speed induction motor, comprising: a housing defining an axis; a plurality of conductive connecting pieces mounted in said housing and adapted to be connected to the induction motor, said conductive connecting pieces having distal contact parts that surround said axis, said distal contact parts of any two of said conductive connecting pieces forming at least one of an angular difference and a height difference therebetween with respect to said axis; a rotary member mounted in said housing and rotatable about said axis, said rotary member being formed with at least three contacting regions that are arranged along said axis and that are in sliding contact with said distal contact parts of said conductive connecting pieces, at least one of said contacting regions having a set of non-contiguous conductive areas, at least one of which extending to one of said conductive areas of an adjacent one of said contacting regions; and a driving unit coupled to said rotary member, extending outwardly of said housing, and operable so as to drive rotation of said rotary member in said housing about said axis such that said conductive connecting pieces are bridged selectively and electrically by said contacting regions of said rotary member to thereby obtain a plurality of combinations of electrical connections for varying speed of the induction motor.