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.

An electric working machine in one aspect of the present disclosure includes two or more circuits and a control circuit. The control circuit executes two or more diagnoses one by one in order. The diagnoses at least include a first diagnosis and a second diagnosis. The first diagnosis diagnoses a first circuit. The second diagnosis diagnoses a second circuit. The control circuit executes the first diagnosis or the second diagnosis at a first diagnosis timing. The control circuit executes the first diagnosis or the second diagnosis at a second diagnosis timing. The second diagnosis timing follows the first diagnosis timing.

The invention concerns a method using a robot for an automatic treatment of a weed, the method comprises steps of capturing images of said weed with a camera on said robot; determining with said images a distance between the weed and a second vegetable organism; and selecting a treatment tool of said robot for a treatment of the weed from a group of treatment tools as function of said distance. The invention further concerns a robotic vehicle for carrying out the method for an automatic treatment of a weed.

A cutting head for use with a cutting tool, such as a grass trimmer. The cutting head has a housing, a line spool and a supporting cap. One end of the housing is coupled to an end of a motor output shaft and another end has an opening. A line spool is disposed in the housing and rotates along with the housing. At least one end of a line wound around the line spool extends out of the housing. The supporting cap is rotatably disposed at the end of the line spool adjacent to the opening and is exposed to an exterior of the housing through the opening.

A string trimmer attachment assembly for edging a lawn includes a weed trimmer that has a pole, a gear head that is coupled to the pole and a trimming head that is rotatably coupled to the gear head. The gear head is angled between the pole and the trimming head. A rolling unit is removably coupled to the pole of the weed trimmer. The rolling unit is oriented to extend along a perpendicular axis with respect to a rotational axis of the trimming head. Additionally, the rolling unit horizontally orients the rotational axis of the trimming head when the rolling unit is positioned to roll along a support surface. In this way the trimming head is positioned to perform edging along a vertical edge.

A transmission shaft assembly includes a connecting tube extended along a central axis, a transmission shaft being a rigid shaft made of metal material, which is extended along the central axis and disposed in the connecting tube, a first limiting element disposed on an end of the connecting tube and formed with a first hole allowing the transmission shaft to pass there through, a second limiting element disposed on the other end of the connecting tube and formed with a second hole allowing the transmission shaft to pass there through, and a bushing. The bushing includes a main body formed with a channel extended along the central axis and several projecting parts disposed on the periphery of the main body. The bushing is located in the connecting tube and disposed between the first limiting element and the second limiting element. The transmission shaft passes through the first hole, the channel, and the second hole successively.

A blade assembly for cutting roots is installed on a hand-carried weed cutter or hand-carried sidewalk edger. The blade assembly comprises a rear blade configured to support a plurality of blades on the shaft of the weed cutter. The rear blade has a plurality of teeth disposed around its perimeter, and a central opening configured to be received by the shaft of the weed trimmer. A front blade has a plurality of teeth disposed around its perimeter. Stacks of grinding segments are sandwiched together between the rear blade and the front blade, each stack of grinding segments extending partially around the blade assembly at an angle. Each grinding segment has a plurality of teeth disposed along an outer edge of the grinding segment. Spacers without teeth are adjacent to and separate the stacks of grinding segments from one another. The spacers are also sandwiched between the rear blade and the front blade.

Described herein is a combination apparatus and methods of using the combination apparatus. The combination apparatus is operable as both an edger and a sod cutter. The combination apparatus includes an arm that oscillates when driven by a motor. Both a sod cutter blade and an edger blade are coupled to the arm.

An outdoor surface treating apparatus having a body having a handle and a head arranged to be removably connected with an accessory tool assembly. The head includes a first engagement arrangement for releasably engaging with a second engagement arrangement in the accessory tool assembly. A drive unit, arranged in the head, includes a first coupling member for drivingly coupling with a second coupling member in the accessory tool assembly. The first engagement arrangement is fixed. The second engagement arrangement is movable between an extended position and a retracted position. The accessory tool assembly includes a biasing element for biasing the second engagement arrangement into the extended position. As the accessory tool assembly is aligned with the head, in particular when the first engagement arrangement is aligned with the second engagement arrangement, and is moved along a movement axis into engagement with the head, the second engagement arrangement first moves over the first engagement arrangement against the bias then returns to the extended position and locks with the first engagement arrangement while the first coupling member couples with the second coupling member.

A plant sawing assembly for removing plants around a sprinkler head includes a hole saw that may be positioned around a sprinkler head to remove plants growing around the sprinkler head. A receiver extends upwardly from the hole saw and a shaft is removably positioned in the receiver. The shaft is coupled to a power tool thereby facilitating the power tool to spin the hole saw to cut the plants.