| 摘要 |
AIRFLOW SWITCH FOR AIR DUCTS An airflow switch for sensing airflow or lack OF same in an air duct comprising a housing base, mounting in side-by-side relation an adjustable range spring and a single-pole double-throw snap action microswitch, with the microswitch having its actuating lever operated by a bellcrank type input lever against an adjustable spring bias applied thereto by the range spring, with the housing base having an open center across which is secured a metallic disc that forms with the base an essentially isolated chamber in which the input lever is disposed, with sealing gasketing being applied to and about the disc rim, and with the disc being formed adjacent the mid portion thereof with a cross aperture through which the shank of a vane assembly extends for securement to the bellcrank input lever for operation of the vane assembly against the range spring bias; the vane assembly includes a vane adapted to be disposed well within the duct, and the vane assembly shank is dust sealed thereabout adjacent the disc through aperture by flexible sealing fingers that dust seal the chamber, in which the bellcrank operates, from dust in the duct airflow. |
