A chainsaw as a working machine, which switches among stop, drive, and choke operations of an internal combustion engine, includes an operation lever that is turnable, a turning member turnably combined with the operation lever, and a torsion coil spring holding abutting of the operation lever and the turning member. The turning member is coupled to a choke operating member via a choke rod and is regulated in turning from drive position to stop position. When the operation lever is turned from drive position to choke position, the turning member also turns to move the choke rod, by which the choke operating member closes the choke valve. Meanwhile, the operation lever is turned from drive position to stop position, against the turning force of the torsion coil spring.

The invention relates to a method for operating a work apparatus having a combustion engine. An ignition device is provided for triggering an ignition spark at a spark plug for igniting a fuel/air mixture in a combustion chamber of the combustion engine. The combustion chamber is bounded by a piston which drives a crankshaft in a rotating manner. In order to avoid the combustion engine stopping in rich mode, the speed (n) of the combustion engine is monitored over the period of time (t, T) and the ignition point (ZZP) of the ignition device is advanced if the speed (n) of the combustion engine lies within a predefined speed range (n.sub.min; n.sub.max) within a predefined period of time (t, T) and then the speed n drops below a speed limit value (n.sub.G).

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 garden tool, comprising a machine body (1), wherein a power portion (2) on a prime mover is arranged in the machine body (1), and a mechanical brake assembly (3) for braking the power portion is arranged in the machine body (1); the mechanical brake assembly (3) comprises a brake control member and a position limiting member, wherein the brake control member comprises a handle (31) and a first mechanical brake sheet (32), and the handle (31) is linked with the first mechanical brake sheet (32); a first position of the brake control member is formed when the first mechanical brake sheet (32) is away from the power portion (2), and a second position of the brake control member is formed when the first mechanical brake sheet (32) is in pressing contact with the power portion (2); and the position limiting member comprises an elastic member (4), and is configured to keep the brake control member in the first position or the second position. According to the garden tool, the brake control member is in pressing contact with the power portion (2), such that the power portion (2) is decelerated or stopped, and a braking state or a non-braking state is maintained through the elastic member (4). The garden tool is simple in structure and high in reliability.

Chainsaws are provided. A chainsaw includes a guide bar include an outer track. The chainsaw also includes a chain movably coupled to the outer track. The chainsaw further includes a housing defining an interior, wherein at least a portion of the guide bar and at least a portion of the motive device are disposed in the interior. The housing includes an upper surface and a lower surface spaced apart along a vertical axis, a first side surface and a second side surface spaced apart along a lateral axis, and a front surface and a rear surface spaced apart along a longitudinal axis. The chainsaw still further includes a motive device mounted within the interior and operable to move the chain relative to the guide bar.

A working machine is provided that includes a working portion and a main body portion including a main body case, an operation mechanism and a power switch. The operation mechanism includes a trigger lever, a lockout lever, and a restricting portion. The trigger lever includes a trigger lever body, and an operation portion including a projection portion. When an external force toward the main body case is applied to the trigger lever body, the projection portion of the operation portion comes into contact with the restricting portion and the trigger lever body comes into contact with the lockout lever, so that the trigger lever body is prevented from rotating relative to the main body case. When the working machine is viewed from a normal direction of a flat surface while being placed on the flat surface, a rotation center of the trigger lever body overlaps with the power switch.

A chainsaw includes a tool body and a power supply device, where the power supply device is configured to provide a power source for the tool body. The tool body includes: a housing; a chain configured to perform a cutting function; a guide plate for supporting and guiding the chain; a drive device, where the drive device is at least partially disposed in an accommodating space formed by the housing and includes a motor configured to drive the chain; and a brake device configured to brake the drive device. The tool body includes a main machine. The main machine includes at least the housing, the drive device, and the brake device. The motor is an outrunner. The power-to-mass density of the main machine is greater than or equal to 0.5 kW/kg and less than or equal to 2.0 kW/kg.

A system for protecting an operator (110) of a power tool (100) may include a first sensor network (240), a second sensor network (250), a third sensor network (252), and a controller (140) configured to detect a trigger event based on measurements made by the first, second and third sensor networks (240, 250 and 252) and initiate a protective action with respect to the power tool (100) responsive to detecting the trigger event. The controller (140) may be further configured to monitor performance data associated with each of the first, second and third sensor networks (240, 250 and 252) to perform sensor fusion based on the performance data.

A handheld, portable work apparatus includes a housing defining an interior space, a drive motor arranged in the housing for driving a tool, a brake device assigned to the tool, a hand guard, and a switching unit which is arranged in the interior space of the housing for detecting the position of the brake device. The hand guard is arranged outside the housing and has an actuation contour for actuating the switching unit. The housing has an elastic element. The hand guard, the elastic element and the switching unit are arranged relative to one another such that the switching unit can be actuated by the elastic element being pushed in via the actuation contour of the hand guard.

A working machine is provided that includes a working portion and a main body portion including a main body case, an operation mechanism and a power switch. The operation mechanism includes a trigger lever, a lockout lever, and a restricting portion. The trigger lever includes a trigger lever body, and an operation portion including a projection portion. When an external force toward the main body case is applied to the trigger lever body, the projection portion of the operation portion comes into contact with the restricting portion and the trigger lever body comes into contact with the lockout lever, so that the trigger lever body is prevented from rotating relative to the main body case. When the working machine is viewed from a normal direction of a flat surface while being placed on the flat surface, a rotation center of the trigger lever body overlaps with the power switch.