Patent ID: 6470603
Filing Date: 2002-10-29
Classification: F16D,F16H

Abstract:
A walk behind self-propelled snowplow comprising:a frame; a snowplow mechanism supported by the frame and having a rotating shaft, and an auger and a blower connected in driven relation to the rotating shaft; an engine supported by the frame for driving the snowplow mechanism; a belt drive power transmission mechanism for transmitting rotational power from the engine to the rotating shaft, the power transmission mechanism having a driving pulley releasably coupled with an output shaft of the engine, an electromagnetic clutch adapted to be engaged and disengaged for connecting and disconnecting the engine output shaft and the driving pulley, a driven pulley connected to the rotating shaft, and an endless drive belt entrained around the driving and driven pulleys; and an overload protection device associated with the belt drive power transmission mechanism for protecting the engine against overload, the overload protection device comprising a tension sensor for detecting a tension in the endless belt and generating an electric overload signal to disengage the electromagnetic clutch when the detected belt tension is greater than a predetermined value, the tension sensor comprising a tension roller, bias means for applying a bias force to urge the tension roller against an outer circumferential surface of the endless belt to cause a tension run of the belt to flex inwardly, and a detector unit for detecting displacement of the tension roller in a direction outward of the endless belt when the tension run of the belt is stretched substantially due to an overload acting on the snowplow mechanism.