High speed stone cutting chain saw - has inserts protecting chain at junctions with drive and return wheels

摘要

The stone cutting chain saw has a toothed driving wheel (3) at the rear and a return wheel (13) at the front. The arm (4) between them has curved sides to guide the cutting chain. At the regions where the chain runs onto and away from these two wheels are inserts (9, 12) which partially enclose the chain. The insert (12) at the driving wheel (1) has a yoke shaped portion with two side plates (12) with a cut out to clear the wheel spindle. The insert (9) at the return wheel (13) has a tongue (9) each side to cover the region where the chain is tangential to the return wheel (13). Each tongue has a curved edge which matches the periphery of the return wheel.