Kombinierte Sägeketten-Bremstrommel-Stoppvorrichtung für eine elektrisch angetriebene Kettensäge

摘要

The chain (CH) of an electromotive chain saw (10) is quickly stopped by the combined use of an electric brake and a mechanical brake (40) when a trigger member (15) is turned off. The rear end of a brake band (23) disposed to tighten a brake drum by operating a hand guard (17) is secured to a bent rod (41). When the trigger member (15) is released, the brake band (23) is normally tightened around the outer periphery of a brake drum (21) by the urging force of a coil spring (34). When the trigger member is released, a circuit provided with a brake winding is closed, thereby applying a dynamic braking force. When the dynamic brake force is applied, a centrifugal clutch is released quickly and the speed of stopping the brake drum (21) is accelerated.