| 摘要 |
<p>A rotary hammer and a power tool. The rotary hammer is operable in an idle mode and a hammer mode and comprises a housing (14) and a barrel (50) positioned in the housing and having a forward portion. A ram (78) is positioned within the barrel and is movable relative to the barrel between hammering positions and an idle position. In some aspects, a ram catcher assembly (110) is positioned along the axis adjacent the forward portion of the barrel to releasably hold the ram (78) in the idle position. The ram catcher (110) assembly includes a friction member (114) frictionally engageable with the ram and a damping member (118) at least partially surrounding the friction member. As the ram moves to the idle position with a force, the damping member absorbs at least a portion of the force and the friction member (114) applies friction to the ram. Also disclosed is a ventilated crank case, an air cooled damping member (116), a chuck configuration using a transverse pin (146), and an air cushion for the ram as its enters the idle position.</p> |
