The Segment is the semi-circular metal block with slots that holds all the type bars in place. The Fulcrum wire (also known as the segment wire) is a thin, strong wire that passes through the pivot holes of all the type bars within the segment slots.
Function: It acts as the common axis or "pivot point" for all type bars. When you press a key, the type bar swings upward, rotating around this wire to strike the platen.
