A string trimmer includes: a housing; a line container, configured to accommodate a trimmer line, and an end of the trimmer line extending out of the line container; a motor, configured to drive the line container to rotate to perform cutting work; a start switch, configured to generate a start signal according to an operation of a user, to control the motor to start or stop; a release mechanism, capable of selectively releasing the trimmer line, to increase the length of the trimmer line that has extended out of the line container; and a calculation unit, configured to respond to a release signal to calculate the usage and/or remainder of the trimmer line. In the embodiments of the present disclosure, the calculation unit configured to calculate the usage and/or remainder of the trimmer line is disposed in the string trimmer. In this way, when currently the usable amount of the trimmer line in the string trimmer is relatively small, the user can be reminded to change the trimmer line in time, thereby reducing the waste of time and labor during use because the trimmer line is used up.

A vegetation cutting device comprises: a rotating cutting head and having a cutting line, the cutting line arranged to define a swath for cutting vegetation. A cutting line feeding mechanism comprises a counterweight for balancing a free end of the cutting line protruding from the cutting head, the counterweight being configured to actuate the cutting line feeding mechanism and feed more cutting line when the length of free end the cutting line is shorter than or equal to a feed length. A guide wheel is mounted on the vegetation cutting device and has an outer surface for engaging the ground. The guide wheel is moveable between a retracted position and an extended position wherein when the guide wheel is in the retracted position, the feed length is substantially equal to a distance between the outer surface of the guide wheel engaging the ground and the cutting head.

A hand-held cutting device (10) including an elongated member (45) graspable along a portion thereof by an operator, a trimmer head (25) disposed at one end of the elongated member, and a power unit operably coupled to the trimmer head to selectively cause rotation of the trimmer head, wherein the trimmer head comprises a line holding assembly (110) to hold and selectively release the trimmer line (70) and a housing to house the line holding assembly, wherein the line holding assembly includes a core (340) having a first portion (342) and a second portion (350), and a spool (130) configured to hold trimmer line that is operably coupled to the core, and wherein the second portion of the core is non-rotatably fixed to the first portion of the core when the trimmer head is in an at-rest state, and is rotatable with respect to the first position of the core when the trimmer head is in an in-use state and rotating.

A line(F)-type trimmer head (1) is described, configured to rotate around a rotation axis (A-A) and comprising a housing (3) composed of at least one first housing portion (5) and one second housing portion (7), which can be torsionally and axially coupled to one another and which form a volume for a stock of cutting line (F). The second housing portion comprises at least one first passage (31), transverse with respect to the rotation axis of the trimmer head, with a first end and a second end configured and arranged so as to be positioned in correspondence of the two exit holes (9) for the cutting line, so that a cutting line can be inserted through one exit hole and extracted from the other exit hole, passing along the first transverse passage.

A strand trimmer and method of use thereof. The strand trimmer includes a pair of pivotable arms each having a motor, a follower wheel, and a cutter-spindle assembly disposed thereon. The arms are biased toward one another and are guided by the follower wheels to pivot around obstacles passing between the arms. The motor rotates the cutter-spindle assembly to move cutting strands extending therefrom through a cutting path with sufficient rotational velocity to cut vegetation. The cutter-spindle assembly includes a reloadable spool and a strand-feed mechanism. The strand-feed mechanism includes a solenoid actuated plunger within a shaft of the cutter-spindle assembly which operates to non-contactingly actuate the plunger to feed out a length of strand. The solenoid is non-rotatably carried on the trimmer arm while the shaft of the cutter-spindle assembly is encircled by and rotated within the solenoid.

A grass trimming head includes a housing assembly and a spool. The housing assembly is formed with a housing cavity and an outer aperture for allowing a cutting line to be inserted from an outside of the housing assembly into the housing cavity. At least a portion of the spool is arranged inside the housing cavity, and the spool is rotatable with respect to the housing assembly about a central axis. The spool is formed with an inner aperture for allowing the cutting line to be inserted into the spool or a clamping portion configured to fix the cutting line.

An automatic feed system for a trimmer is provided. Such trimmers include a line that can be spun at high speeds to cut vegetation along roadsides or other areas. The automatic feed system is configured to dynamically detect the current length of the line and automatically feed the line to maintain a maximum or desired length for cutting. This length may typically correspond with the radius of a trimmer deck in which the line spins.

A robotic lawnmower comprising a robotic body and a trimmer mechanism. A mount column hole is arranged in a side face of the robotic body. The trimmer mechanism includes a mount, a trimmer head and a drive motor. The mount includes a stand and a connection portion. The connection portion is fixedly connected to the stand and configured to be inserted into the mount hole. The trimmer head is rotatably arranged on a bottom face of the stand. The drive motor is configured to drive the trimmer head to rotate. The robotic lawnmower with the trimmer mechanism is capable of covering and trimming the areas within a specific width distant from the edges of the lawns, which effectively solves the problem that the conventional robotic lawnmowers are incapable of covering and trimming such areas of the lawns, reduces manual workload, and lowers cost of manpower.

A trimmer head that includes a casing to be coupled to a driveshaft. The casing includes an upper shell and a lower shell, with the lower shell including a second toothing that protrudes upwardly. The trimmer head further includes an upper disk and a lower disk within the casing, with the lower disk including a first toothing that protrudes downwardly. A spool of cutting wire is positioned between the lower disk and the upper disk. In an engagement position, the first toothing and the second toothing are engaged and the upper disk and lower disk rotate with the lower shell. In a free position, the first toothing and the second toothing are disengaged and the upper disk and lower disk rotate with respect to the lower shell.

An accessory mount device for a power tool, wherein a reference axis forms an axis of rotation of the accessory mount device, the accessory mount device including a housing forming an interior volume, the housing including a ramped surface in the interior volume at which a bearing is positioned; a first plate forming a channel at which the bearing is positioned at the ramped surface to push the first plate along the reference axis; and a second plate configured to push a spool in the direction of the reference axis, wherein the bearing is configured to selectively push the first plate to the second plate when a centrifugal force threshold is exceeded, and wherein the second plate is allowed to rotate around the reference axis separate from the first plate.