Patent ID: 6307461
Filing Date: 2001-10-23
Classification: H01H

Abstract:
A condition responsive electric switch comprising:a housing;a first electrical contact and a second electrical contact within the housing, at least one of said first and second contacts moveable between an open position breaking an electrical circuit and a closed position completing an electrical circuit in response to environmental conditions outside said housing;an actuator arm pivotally mounted within said housing for moving at least one of said first electrical contact and said second electrical contact;a rotatable shaft partially extending through said housing, said shaft comprising a center axis;a cam within said housing and connected to said shaft, said cam comprising a cam surface comprising a first portion, a second portion, and a third portion, said cam surface first portion comprises a first end and a second end, said first end positioned a greater radial distance from said center axis than said second end, said cam surface second portion comprises a first end and a second end, said first end positioned a greater radial distance from said center axis than said second end, said cam surface third portion longitudinally displaced from said cam surface first portion and second portion relative to said shaft center axis, said cam surface third portion positioned a greater radial distance from said center axis than said first end of said second portion;a cam follower contacting said cam surface, said cam follower moveable in response to said cam surface as said cam and said shaft are rotated; anda spring connected to said cam follower and to said actuator arm, said spring including a preset calibration position corresponding to a preset calibration load and an adjustable calibration position corresponding to an adjustable load from rotation of said shaft and said cam when said cam follower contacts said cam surface first portion, said spring connected to said actuator arm such that said spring is returned to said preset calibration position when said cam follower contacts said second portion.