US Patent 11937541 Grass cutting head and grass trimmer using the same

A grass cutting head includes a spool for winding a grass cutting line, a head housing for accommodating the spool, a first guiding structure disposed at least partially in the head housing, and a second guiding structure formed on the spool. The first guiding structure guides the grass cutting line through the head housing when threading the grass cutting line. The second guiding structure guides the grass cutting line to move and be wound around the spool by relative motion created between the spool and the head housing. The head housing includes a first housing and a second housing. The first guiding structure is disposed at least partially in the first housing. The spool is disposed between the first housing and the second housing. The first housing or the second housing is provided with an outer threading hole for allowing the grass cutting line to pass in or out.