Abstract: A pipe-shaped fixture (100) to be attached to a housing (120) of a work machine includes a fixture body (102) having a front-end projection (110) and a rear-end projection (112) that make front and rear limits of a rubber cushion (104) that encloses the fixture body (102) closely and circumferentially. The front- and rear-end projections (110, 112) are connected to each other by a plurality of longitudinally extending ridges (114) formed at circumferential intervals. The ridges (114), front- and rear-end projections (110, 112) define a plurality of concavities (116) surrounded thereby on the outer circumference of the fixture body (102). The front- and rear-end projections (110, 112) cause longitudinal vibration of an operation rod (130) relative to the housing (120) to act as a compression force on the rubber cushion (104), and thereby suppress longitudinal vibration of the operation rod (130) while maintaining effects of suppressing horizontal and vertical vibrations.

Abstract: A portable power tool includes an internal combustion engine that includes a crankshaft in which a load applied thereto is unevenly distributed along the axis of the crankshaft with respect to the axis of the reciprocating movement of a piston. The portable power tool also includes operational members that are driven by the internal combustion engine, a rotational body fixed to an end of the crankshaft to which a smaller component of the load is applied, and a balancing weight provided on the rotational body for absorbing vibrations generated by the reciprocating movement of the piston. The centroid of the balancing weight is disposed at an angular position from 140 degrees to 180 degrees with respect to the axis of the reciprocating movement of the piston in a rotational direction of the rotational body, when the piston is positioned at a top dead center.

Abstract: A portable power tool includes an internal combustion engine that includes a crankshaft in which a load applied thereto is unevenly distributed along the axis of the crankshaft with respect to the axis of the reciprocating movement of a piston. The portable power tool also includes operational members that are driven by the internal combustion engine, a rotational body fixed to an end of the crankshaft to which a smaller component of the load is applied, and a balancing weight provided on the rotational body for absorbing vibrations generated by the reciprocating movement of the piston. The centroid of the balancing weight is disposed at an angular position from 140 degrees to 180 degrees with respect to the axis of the reciprocating movement of the piston in a rotational direction of the rotational body, when the piston is positioned at a top dead center.

Abstract: A backpack frame for mounting a blower having an inlet port is provided with an intake air muffler on a surface facing the inlet port. The intake air muffler may be formed of a large number of through holes which are communicated with the backpack frame and have a small diameter and no angular portions, or a large number of dimples with a small diameter formed on the surface.