Pressure responsive switch

摘要

A sealed pressure-responsive switch is manually resettable and trip-free. The switch has a separate snap-acting, bistable, dished metal disc or disc element disposed between a sealed snap-acting pressure-responsive diaphragm and a spring-biased switch arm. The disc moves to an inverted dished configuration with snap action to move the switch arm to a trip position against the arm bias when the diaphragm moves in response to application of a selected fluid pressure. The disc remains in its inverted shape to releasably hold the arm in tripped position until the switch is manually reset even when the diaphragm returns to its original position after removal of the selected fluid pressure from the diaphragm. A push button or push button means is selectively movable to apply a force to the disc sufficient to restore the disc to its original disc configuration after the fluid pressure is removed from the diaphragm, thereby to permit the switch arm to reset in response to its spring bias and provide trip-free manual reset switch operation.