Centrifugal actuator for motor starting switch

Claim 1

In an electric motor having a starting winding, a starting switch for energizing and deenergizing the starting winding, a rotor shaft, and a centrifugal actuator for actuation of said starting switch, said centrifugal actuator being rotatable with said rotor shaft, said centrifugal actuator having a pair of movable members disposed on opposite sides of said rotor shaft centrifugally responsive to the rotational speed of the shaft for moving outwardly from a starting position to a run position upon rotation of said rotor shaft at a predetermined operational speed, means for resiliently biasing said movable members toward their starting position, said movable members being movable from their run to their starting positions upon said shaft slowing down from said predetermined speed, said centrifugal actuator being adapted to be operatively interconnected to said starting switch so as to effect opening and closing thereof as said centrifugal actuator moves between its starting and its run position, wherein the improvement comprises: said centrifugal actuator biasing means including a pair of compression coil springs, a pair of linkages, one for each of said springs, each said linkage interconnecting a respective said spring between said movable members, each of said linkages comprising a first element engageable with one end of its respective compression coil spring and with the movable member opposite said one end of said compression spring and a second element engageable with the other end of said compression coil spring and with the other movable member so that movement of said movable members from their starting to their run positions causes said first and second elements to move relative to one another and causes said spring to be resiliently compressed.