Abstract: A self-powered chainsaw, typically a battery powered chainsaw, including a housing, a power source, an endless cutting chain having a plurality of cutting elements and a motor arranged to drive the chain relative to the housing using power from the power source. The chainsaw also includes a sharpening element which is arranged so as to be driven relative to the cutting elements and the housing using the power source.

Abstract: A self-powered chainsaw, typically a battery powered chainsaw, comprising a housing (1; 21), a power source (5; 25), a endless cutting chain (4; 24) having a plurality of cutting elements and a motor (6) arranged to drive the chain (4; 24) relative to the housing (1; 21) using power from the power source (5; 25), in which the chainsaw further comprises a sharpening element (12; 32) which is arranged so as to be driven relative to the cutting elements and the housing (1; 21) using the power source (5; 25).

Abstract: A typically battery-operated power tool, such as a chainsaw or hedge trimmer, comprising a working element (4), a motor (6) arranged to drive the working element (4) and a controller (9) arranged to control the speed at which the motor drives the working element (4), in which there is provided a sensor (12) for at least one factor indicative of the efficiency with which the power tool is being operated, the controller (9) being arranged to vary the speed at which the motor (6) drives the working element (4) should the factor indicate that the power tool is being operated in a sub-optimal manner. Typically, the factor is the pressure which the user is applying the power tool, and the sensor (12) is a sensor for the current flowing through the motor (6).