A guide bar for a chain saw comprising two opposite elongate surfaces and a slot formed between said opposite sides running along the periphery of the guide bar, in order to receive and retain the chain during cutting. At least one of the elongate surfaces is furrowed across its surface in the direction of the cutting movement of the guide bar. The invention also relates to an apparatus for operating the chain saw in a forestry machine.

A chainsaw having a scraper used to clean or debark wood before a saw chain makes a cut is disclosed. The chainsaw includes a housing, a first casing and a second casing coupled to the housing. The first casing has a plurality of first spikes and the second casing has a plurality of second spikes. Further, the chainsaw includes a guide bar coupled to the housing. Additionally, the chainsaw includes a saw chain provided around the guide bar. The chainsaw further includes a scraper coupled to the first casing and the second casing. The scraper is aligned in axis with the saw chain. The scraper is used to clear dirt or debark on wood before the saw chain makes a cut on the wood. Thereby, protecting the teeth of the chain of the chainsaw as to extend its lifespan and require less sharpening of the teeth of the chain.

A power tool includes a function member, a motor, a driving circuit electrically connected to the motor to drive the motor, and a first control module configured to output a first control signal to the driving circuit. The first control module has a first working state and a first failure state. The first control module outputs a first working signal when the first control module is in the first working state, and outputs a first failure signal when the first control module is in the first failure state. A second control module is electrically connected to the first control module to receive the first working signal or the first failure signal from the first control module. The second control module outputs a second control signal to turn off the motor when the second control module receives the first failure signal from the first control module.

A handheld work apparatus includes a first assembly, a second assembly and an anti-vibration unit which includes a coil spring. A first end of the coil spring forms a fastening eyelet fixed to the first assembly by an attachment screw which extends through the fastening eyelet and the head thereof projects into the coil spring. A second end of the coil spring is screwed onto a connecting piece of the second assembly which has an opening extending through the connecting piece and through which an engagement contour in the head of the attachment screw is accessible for a tool. When the work apparatus is in a non-loaded state, the distance (f) between the fastening eyelet and a front end of the connecting piece is the length (g) of the attachment screw. The distance (p) of the above support surface from the front end of the connecting piece is the length (g).

A cutting device includes a housing formed with a handle portion and an accommodation portion, a cutting portion connected to the housing and at least partially disposed in the accommodation portion, a motor disposed in the accommodation portion and extending in a first linear direction, and a bottom plate extending in a plane of the bottom plate and formed with an opening through which at least part of the cutting portion passes. The cutting device further includes a worm gear and worm structure disposed in the accommodation portion. The cutting portion includes a chain and a guide plate connected to the housing and used for supporting the chain. The motor includes an output shaft, the cutting portion is connected to a driving shaft, the output shaft transmits power to the driving shaft through a worm gear and a worm, and the driving shaft is capable of driving the chain.

A rope severing guard is engageable around a rope or flexible member to protect it from severing by a chainsaw cutting chain. The guard has a flexible body having a rope passage through which a protected rope is positioned. An interior cavity in the body of the rope severing guard is filled flexible fibers which if contacted by a moving cutting chain of a chainsaw, will form clogging engagements with the cutting chain and the chain support it moves upon or with the cutting chain and the motor drive gear powering it.

A chainsaw includes a handle with a handgrip; an electric motor for endlessly moving a saw chain; a control unit for controlling rotation of the motor; and a main power switch switchable between an ON state and an OFF state. The handgrip is provided with a gripping detection device for detecting whether the handgrip is gripped by the worker, and the chainsaw is configured to, when the control unit is manipulated to deactivate the electric motor in a state in which the gripping detection device detects that the handgrip is gripped, maintain the main power switch in the ON state, and to, when the control unit is manipulated to deactivate the electric motor in a state in which the gripping detection device detects that the handgrip is not gripped, switch the main power switch to the OFF state.

A guide bar for a chain saw comprising two opposite elongate surfaces and a slot formed between said opposite sides running along the periphery of the guide bar, in order to receive and retain the chain during cutting. At least one of the elongate surfaces is furrowed across its surface in the direction of the cutting movement of the guide bar. The invention also relates to an apparatus for operating the chain saw in a forestry machine.

A power saw system has a power saw with housing; guide bar; and saw chain driven about the guide bar by an electric drive motor. A battery is arranged outside of the housing. A power cable is connected with its first end through an electrical connection to the battery and with the second end to the drive motor to supply the drive motor with power. An elastic securing element is connected by a fastening element to the housing. A connecting device connects by a mechanical connection the securing element to an operator of the power saw. The connecting device has an overload protection separating the mechanical connection between securing element and operator when a maximum pulling force is surpassed. Securing element and power cable form a cable assembly. A pull-out force for separating the electrical connection is smaller than the maximum pulling force.

A chainsaw includes a handle with a handgrip; an electric motor for endlessly moving a saw chain; a control unit for controlling rotation of the motor; and a main power switch switchable between an ON state and an OFF state. The handgrip is provided with a gripping detection device for detecting whether the handgrip is gripped by the worker, and the chainsaw is configured to, when the control unit is manipulated to deactivate the electric motor in a state in which the gripping detection device detects that the handgrip is gripped, maintain the main power switch in the ON state, and to, when the control unit is manipulated to deactivate the electric motor in a state in which the gripping detection device detects that the handgrip is not gripped, switch the main power switch to the OFF state.