Sensor switch

A sensor switch comprising:

• a ceramic body made from a plurality of raw ceramic blanks that are sintered after being stacked, said ceramic body including an intermediate layer assembly having an intermediate layer inner peripheral surface that defines a through hole, a first side layer assembly disposed on one side of said intermediate layer assembly and closing one end of said through hole, and a second side layer assembly disposed on the other side of said intermediate layer assembly and closing the other end of said through hole, said first side layer assembly having a first groove that opens toward said through hole and that communicates with said through hole, and a first side layer outer peripheral surface, said second side layer assembly having a second groove that opens toward said through hole and that communicates with said through hole, and a second side layer outer peripheral surface;
• and
• a first conductive unit made of metal and including a first conductive layer disposed in said first groove and having a first contact surface facing said through hole, and at least one first internal circuit connected to said first conductive layer and extending from said first conductive layer to said first side layer outer peripheral surface;
• a second conductive unit made of metal and including a second conductive layer disposed in said second groove and having a second contact surface facing said through hole, and at least one second internal circuit connected to said second conductive layer and extending from said second conductive layer to said second side layer outer peripheral surface;
• said intermediate layer inner peripheral surface, said first contact surface and said second contact surface cooperatively defining a sensing cavity;
• and
• a conductive member rollably disposed in said sensing cavity and movable between a closed circuit position and an open circuit position;
• when said conductive member is in the closed circuit position, said conductive member is simultaneously in contact with said first contact surface and said second contact surface to form a current path;
• and
• when said conductive member is in the open circuit position, said conductive member is not in contact with one or both of said first contact surface and said second contact surface so as not to form a current path.