US Patent 8464431 String head for a trimmer

A trimmer head configured for operating in a fixed line configuration and a bump-feed configuration. The trimmer head includes a base including a cup having a top wall and a substantially cylindrical side wall defining an aperture. The base also includes a collar extending axially from the top wall of the cup for coupling the trimmer head with the output shaft. A fixed line head is at least partially received within the cup when the trimmer head is in the fixed line configuration and a bump-feed spool is at least partially received within the cup of the base when the trimmer head is in the bump-feed configuration.