Abstract: A grass trimmer includes an operating device configured for a user to operate and a grass trimmer device including a grass trimmer head and a motor. The grass trimmer head includes a spool configured for a grass trimmer line to wind around and a housing formed with an accommodating cavity. When the grass trimmer is mounted with the grass trimmer line, a part of the grass trimmer line protruding outside the housing is defined as an effective part of the grass trimmer line. The grass trimmer further includes a controller configured to control the grass trimmer head to release a grass trimmer line when the grass trimmer head is mounted with the grass trimmer line and a length of the effective part is detected to be less than or equal to a preset value.

Abstract: A trimmer head includes a spool formed with a winding portion for winding a trimmer line and a head housing formed with an accommodating space for accommodating at least a portion of the spool. The trimmer head further includes an intermediate element for transmitting a torque between the spool and the head housing such that one of the spool and the head housing rotates with the other. The spool drives the intermediate element to rotate and the intermediate element is slidably connected to the spool in a direction along a rotation axis or parallel to the rotation axis. The spool does not move in the axial direction when the trimmer head of the grass trimmer is unwinding the trimmer line, thereby effectively avoiding the problem of the trimmer line jamming.

Abstract: A trimmer head includes a spool formed with a winding portion for winding a trimmer line and a head housing formed with an accommodating space for accommodating at least a portion of the spool. The trimmer head further includes an intermediate element for transmitting a torque between the spool and the head housing such that one of the spool and the head housing rotates with the other. The spool drives the intermediate element to rotate and the intermediate element is slidably connected to the spool in a direction along a rotation axis or parallel to the rotation axis. The spool does not move in the axial direction when the trimmer head of the grass trimmer is playing the trimmer line, thereby effectively avoiding the problem of the trimmer line jamming.

Abstract: A grass trimmer includes an operating device configured for a user to operate and a grass trimmer device including a grass trimmer head and a motor. The grass trimmer head includes a spool configured for a grass trimmer line to wind around and a housing formed with an accommodating cavity. When the grass trimmer is mounted with the grass trimmer line, a part of the grass trimmer line protruding outside the housing is defined as an effective part of the grass trimmer line. The grass trimmer further includes a controller configured to control the grass trimmer head to release a grass trimmer line when the grass trimmer head is mounted with the grass trimmer line and a length of the effective part is detected to be less than or equal to a preset value.