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.

The invention is directed to a handheld work apparatus having a work tool. The work apparatus defines a longitudinal plane and includes a handle having a longitudinal axis. The blocking lever is mounted so as to be pivotable about a rotational axis. The blocking lever blocks the actuating lever in a blocking or disable position and enables the actuating lever for actuation in at least one operating enable position. In the direction of view perpendicular to the longitudinal plane, the longitudinal axis of the handle and the rotational axis of the blocking lever conjointly define an angle (). The angle () lies in a range of from 10 to 60.

The invention is directed to a handheld work apparatus having a work tool. The work apparatus defines a longitudinal plane and includes a handle having a longitudinal axis. The blocking lever is mounted so as to be pivotable about a rotational axis. The blocking lever blocks the actuating lever in a blocking or disable position and enables the actuating lever for actuation in at least one operating enable position. In the direction of view perpendicular to the longitudinal plane, the longitudinal axis of the handle and the rotational axis of the blocking lever conjointly define an angle (). The angle () lies in a range of from 10 to 60.

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.

Multi-speed automatic transmissions for power tools are provided. A multi-speed automatic transmission includes an output shaft configured to be coupled to a chain sprocket to rotatably drive the chain sprocket, wherein the automatic transmission is configured to automatically shift between a plurality of gear ratios in response to a rotational speed of the output shaft reaching a preset rotational speed.

A an electric machine tool having a body to which a work tool is attached, a motor, and a battery. The body has a motor receiving chamber, a battery receiving chamber opening through an outer surface of the body, and a communication path through which the battery receiving chamber is in communication with the motor receiving chamber. A first air inlet opening is formed between the inner edge of an opening of the battery receiving chamber and the outer periphery of the battery disposed in the battery receiving chamber. Further, an inflow port of the communication path opens to an inner side surface of the battery receiving chamber and an air filter is fitted over the inflow port.

An apparatus and method for managing power supplied to a portable electrical device includes an electrical connector configured to engage a complementary electrical connector of the respective battery. The portable battery-powered device also includes a selector switch configured to couple the electrical connectors of the plurality of power receptacles in at least one of a series configuration, a parallel configuration, and a combination of series and parallel configuration. The portable battery-powered device further includes an electrical load device including one or more electrical leads coupled to the selector switch. The selector switch is selectable during operation of the portable battery-powered device to provide power to the electrical device from a plurality of battery packs coupled in the at least one of a series configuration, a parallel configuration, and a combination of series and parallel configuration.

An interchangeable concrete cutting chainsaw cutting assembly adapted for installation upon a drive assembly in exchange for a removed, different type cutting head assembly. The chainsaw cutting assembly includes a housing that has fasteners that releasably attach the housing to a drive assembly in an installed configuration. A ration transmission has a plurality of interconnected rotation member, each rotatable member having a mounting shaft positioned at a fixed location on the housing by a bearing assembly. The driven member has a receiver that interconnects with a driveshaft of the driver assembly in the installed configuration whereby the driven member is rotated by the drive assembly. The cutting chain drive member operatively interconnected with a drive sprocket whereby rotation of the cutting chain drive member rotates the drive sprocket. The chainsaw cutting assembly is pivotable relative to the drive assembly.

An interchangeable concrete cutting chainsaw cutting assembly adapted for installation upon a drive assembly in exchange for a removed, different type cutting head assembly. The chainsaw cutting assembly includes a housing that has fasteners that releasably attach the housing to a drive assembly in an installed configuration. A ration transmission has a plurality of interconnected rotation member, each rotatable member having a mounting shaft positioned at a fixed location on the housing by a bearing assembly. The driven member has a receiver that interconnects with a driveshaft of the driver assembly in the installed configuration whereby the driven member is rotated by the drive assembly. The cutting chain drive member operatively interconnected with a drive sprocket whereby rotation of the cutting chain drive member rotates the drive sprocket. The chainsaw cutting assembly is pivotable relative to the drive assembly.

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.