Push button switch including dome-shaped movable contact having reverse function

A push button switch, comprising:

• fixed contacts;
• a dome-shaped movable contact disposed above said fixed contacts and having a dome-shaped apex portion;
• a projection formed on an inner surface of said movable contact at a portion excluding said dome-shaped apex portion so as to be in contact with and separated from one of said fixed contacts;
• a housing;
• said fixed contacts disposed on an inner bottom of said housing;
• said movable contact formed of a metal material having a spring property;
• a stem movably disposed to said housing;
• a plurality of projections disposed on said dome-shaped inner surface in a scattered state at positions where they can come into contact with the portion around the center of the fixed contact excluding the center;
• said plurality of projections independently formed in said scattered state;
• said dome-shaped apex portion of said movable contact disposed inwardly of said projections acts as a movable region when said movable contact is reversed;
• a press section disposed at the lower end of said stem and abutted against said dome-shaped apex portion of said movable contact;
• and
• said stem being urged in a direction to project externally of said housing by the pressure of a dome-shaped spring through said press section.