Patent ID: 6918451
Filing Date: 2005-07-19
Classification: F16C,F16D

Abstract:
1. A portable trimmer comprising: an internal combustion engine, said internal combustion engine having a crankshaft; a centrifugal clutch for transferring a rotation of said crankshaft and having a clutch drum, said clutch drum having an outer peripheral surface; an output shaft extending frontward from said centrifugal clutch; a gear case; a cutting blade connected to said output shaft through said gear case; and a brake mechanism for braking said clutch drum, said brake mechanism having a brake band having ends and an inner surface and formed in a curved strip shape extending along said outer peripheral surface of said clutch drum, said brake band being accepted to be tightened around or released from said outer peripheral surface in response to a movement of at least one of said ends, said brake band including a plurality of linings provided on said inner surface and to be opposed to said outer peripheral surface of said clutch drum, said linings being located spaced apart from each other along a longitudinal direction of said brake band; said brake mechanism including means for releasing said brake band and means for adjusting a tightening force of said brake band against said clutch drum; said releasing means having a brake control lever, a spring and a first swingable member which swings between an initial position and a swing position, said first swingable member being biased toward said initial position by said spring which has a proximal end connected thereto, and adapted to be moved to its swing position by said brake control lever, said first swingable member being connected to one of said ends of said brake band in such manner that said brake band is tightened to said clutch drum when said first swingable member is in said initial position, and loosened when said first swingable member is in said swing position; and said adjusting means having a distal-end-position adjusting member connected with a distal end of said spring located on an opposite side of said proximal end attached to said first swingable member, and a screw for moving said distal-end-position adjusting member in a direction to increase or reduce tension of said spring.