PRESSURE SWITCH

PURPOSE:To rotate a moving contact each time when it makes contact with a fixed contact, always change the contact position with a fixed contact and block the deterioration of the moving contact so as to prevent contact failure by forming the moving contact in a spherical shape, and fitting this contact in a housing while supporting it by means of a moving member for setting the contact rotatable. CONSTITUTION:When a pressure P does not act in a pressure introduction hole 30, a moving member 20 is pressed toward a caulking 21 side by the second spring 27, a moving contact 25 is departed from a fixed contact 28, and a pressure switch is in open condition. Then, when the pressure P is applied to the pressure introduction hole 30, the pressure receiving piston 15 moves in the direction to contact the spring 27 through the member 20, and brings the contact 25 in contact with contact 28. By this contact, the contact 25 flexes the first spring 24 while making turning movement and brings it in contact with the contact with 28 by only a specified quantity. This operation happens in each contact so as to bring both contacts 25 and 28 in mutual contact, thus a specified electric signal is allowed to flow. A center housing 12 and a front housing 10 are isolated from each other by a diaphragm 22 so as to avoid contact failure due to leakage of from a gap.