Abstract: Disclosed is a starting device for an internal combustion engine having a stationary bearing axle attached to the engine, a pulley rotatably mounted on the axle and adapted for accepting a starting rope wrapped thereabout, a recessed coupling attached to the drive shaft of the engine, coaxially surrounding the rope pulley in its recess and having a plurality of inwardly facing ratchet teeth.

Abstract: A guiding rail arresting device for motor driven hand saws, especially motor chain saws, in which a sword-shaped guiding rail provided with a guiding groove extending in the longitudinal direction of the guiding rail is adapted to be clamped transverse to the plane of said rail against an abutment having associated therewith a counter guiding member for cooperation with the flanks of the guiding groove. The counter guiding member for at least one of the groove flanks is formed by a supporting element adapted when clamping the rail against the abutment automatically to be clamped against the groove flank.

Abstract: A rotor for a centrifugal clutch which rotor is designed as an axially laminated packet and is provided with a central supporting element carrying at least two circular segmental centrifugal weights respectively having one end thereof connected to the supporting element by an elastic supporting member.

Abstract: A motor chain saw in which serially arranged clutches are interposed between the motor output shaft and the chain of the saw. The clutches include a centrifugal clutch and a mechanically controlled clutch. The mechanically controlled clutch has at least one drive element having an engaged position and a disengaged position and is acted on by centrifugal force urging it toward the position which it occupies. A spring urges the device element toward engaged position with a force less than the centrifugal force which acts on the drive element above a certain speed. The mechanically controlled clutch includes at least one control operable to move the drive element in at least disengaging direction during rotation of the clutch.