| 摘要 |
A lawn mower blade clutch-brake mechanism having a driving drum and a driven blade carrier, the carrier having clutch shoes engageable with the inside of the drum and brake drum segments fixed to the shoes and disposed outside the drum for engagement by an encircling brake band which both applies braking drag and mechanically forces the segments inward to disengage the clutch shoes, and including the improvement that the clutch shoes are pivoted to the carrier at their leading ends in the direction of rotation so as to be aggressive and self-energizing, and the segments are pivoted on the same pivots and have trailing ends which are swung outward from a cylindrical position concentric with the axis of rotation when the clutch shoes are engaged so that the segments are first engaged by the brake band at and in the direction of their outward sloping trailing ends. The segments preferably also have leading ends extending forward beyond the pivot points, which swing inward from concentric position so as to clear the brake band during its initial engagement. Desirably, the clutch shoes are steam-treated, powdered-iron parts and the drum is hardened steel. The mechanism may include a flywheel and is especially compact and adapted to be mounted on an engine shaft without modification of the engine. The particular construction facilitates economical manufacture and improved operation.
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