| 摘要 |
<p>A hand-held powered hammer comprising a hammer housing (2), a spindle (4) rotatably mounted within the housing, a hammering mechanism (24, 28, 32) for generating repeated impacts on a tool or bit mounted at the forward end of the spindle, a spindle lock arrangement (60), comprising at least one spindle lock tooth (66), which arrangement is mounted within the housing and a set of teeth (43) arranged for rotation with the spindle. The hammer, which may be a rotary hammer, has at least two modes including a first mode, which may be a rotary hammer or drilling only mode, in which the spindle is rotatable within the housing and a second mode, which may be a hammer only mode, in which the set of teeth (43) engage the spindle lock tooth or teeth (66) so as to lock the spindle (4) against rotation within the housing. An improved spindle lock arrangement (60) is provided which comprises a resilient synchronising element (72, 74, 92) positioned to engage the set of teeth before the spindle lock tooth or teeth engage the set of teeth on movement from the first mode to the second mode so as to bring the set of teeth into meshing alignment with spindle lock tooth or teeth.</p> |
