PRESSURE RESPONDING SWITCH DEVICE HAVING TOLERANCE HAVING IMPROVED LIFETIME AND WIDE STATIC CONTACT ARRANGEMENT

摘要

PURPOSE: To provide a switch having a very long life expectation by including the center of a diaphragm deflecting between d1 and d2 during pressure buildup and between d2 and d1 during pressure drop and having a pressure-deflection relationship having a relatively small difference to pressure. CONSTITUTION: A diaphragm 60 is formed into a pan shape to obtain nonlinear pressure-toe diaphragm-center-point displacement. The diaphragm 60 has a relatively rigid effective spring coefficient as to increasing pressure from 0Kg/cm2 up to or in excess of a plateau having a range of deflection between d1 and d2 , and its center deflects between d1 and d2 at substantially the same pressure level; i.e., the center of the diaphragm 60 deflecting between d1 and d2 during pressure buildup and between d2 and d1 during pressure drop and having a pressure-deflection relationship having a relatively small difference to the pressure is provided. Then contacts are placed on the d1 side in the d1 -d2 range at the calibrated pressure level to permit contact wear, thus obtaining an excellent effect of continuous operation.