SNAP ACTION MECHANISM AND PRESSURE SWITCH USING THE SAME

摘要

A pressure switch using a snap action mechanism, comprising an external force transmission mechanism separating a cover from a housing. A room partitioned by the cover and the external force transmission mechanism is designated as a first pressure chamber and a room partitioned by the housing and the external force transmission mechanism is designated as a second pressure chamber. The second pressure chamber comprises a movable piece having a first movable part and a second movable part positioned oppositely to each other and one or more fixed contacts. The first movable part is joined to the second movable part through a leaf spring. The second movable part comprises a contact which functions as a movable contact. When the external force transmission mechanism applies an external force to the first movable part, the first movable part is displaced, the second movable part is inverted at the acting point of the first movable part, and the movable contact is brought into contact with the fixed contact.