Operating key part

An operating key part comprising:

• at least one key top having a protrusion extending through at least one hole formed through the outer wall of a main apparatus from the inside of the wall to the outside of the wall;
• at least one hinge key for coming into contact with a switch fitted to the main apparatus by moving in a pushing direction from the front side thereof to the back side thereof, the front side being adapted to come into contact with the back side of the key top in the direction opposite to the pushing direction;
• and
• a single frame positioned near a side of the hinge key and supporting the key as floating through a hinge;
• the key top, the hinge key, the frame, and the hinge being molded integrally out of thermoplastic resin;
• the frame having at least three protrusions positioned on the front side thereof around the center of gravity thereof;
• wherein the front ends of the frame protrusions are positioned at a predetermined distance in the direction opposite to the pushing direction from the position to which the front side of the hinge key has moved farthest in the opposite direction when the front side of the hinge key is fitted to the main apparatus.