An electrically powered rotary hammer comprising a hollow cylindrical spindle (18) mounted rotatably within a housing (2, 4) of the hammer with a tool holder arrangement (16) located at a forward end of the spindle for releasably holding a tool or bit within a forward tool holder portion of the spindle so as to enable limited reciprocation of the tool or bit within the spindle. An air cushion hammering mechanism (20, 21, 22) is located within the spindle for generating repeated impacts on the tool or bit and a rotary drive mechanism comprising a spindle drive gear (62) is mounted rotatably around the spindle for rotationally driving the spindle, or a part of the spindle, via an overload clutch. The overload clutch comprises a clutch ring (96) rotatably mounted around the spindle so as to have limited rotational movement with respect to the spindle drive gear and so as to be rotatably driven by the spindle drive gear via at least one spring element (94). At least one locking member (90) carried by the clutch ring is arranged so as to be shiftable with respect to the clutch ring from a first position in which the locking members transmit rotary drive from the clutch ring to the spindle. The overload clutch is arranged such that below a predetermined torque threshold the spring element or elements maintain(s) the spindle drive gear and the clutch ring in a relative rotational position in which the spindle drive gear locks the locking member or members in the first position and such that above the torque threshold the spring element or elements deform(s) and the relative rotational position of the spindle drive gear and the clutch ring changes so that the locking member or members move(s) out of the first position. IMAGE
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