| 20090255796 | DIFFERENTIAL ADJUSTMENT MECHANISM FOR PRESSURE SWITCHES - A calibration mechanism for setting the tripping point of a microswitch in a pressure switch has a lower collar fixed to the upper end of the pressure switch push rod, and an upper collar disposed above the lower collar and adapted to actuate the trigger of the microswitch when raised a sufficient distance above the lower collar. The upper and lower collars each have a threaded bore, each with a different thread pitch, plus guide means for keeping the threaded bores aligned for receiving a double-threaded adjustment screw having an upper section threaded to engage the upper collar's threaded bore, and a lower end threaded to engage the lower collar's threaded bore. Due to the different thread pitches, rotation of the adjustment screw will cause gradual movement of the upper collar either toward or away from the lower collar, thus facilitating fine adjustment of the microswitch trigger point. The calibration mechanism may also include a reset mechanism, operable on similar principles to set the mieroswitch's reset point. | 10-15-2009 |
