A hammer drill having a motor mounted within a body and an output spindle; a tool holder mounted on the body capable of holding a cutting tool; a hammer mechanism having a piston; a reciprocating drive for converting rotary movement of the motor into reciprocating movement of the piston; a ram reciprocatingly driven by the piston via an air spring to strike a cutting tool held in the tool holder, the hammer mechanism performing one hammer cycle each time the ram strikes a cutting tool during normal use; an air replenishment mechanism capable of refreshing the air spring during certain time periods during normal use; the air replenishment mechanism capable of being adjusted to refresh the air spring during time periods within the hammer cycle and/or the system allows different volumes of air into or out of the air spring during the refreshment time periods.

A hydraulic hammer including a housing, a piston arranged for reciprocating movement within the housing, a hydraulic circuit within the housing. The hydraulic circuit is configured for connection to a source of pressurized fluid. The hydraulic circuit includes an inlet passage configured to provide a hydraulic fluid to the piston, an outlet passage configured to provide a return flow path for the hydraulic fluid from the piston a bypass passage selectively connecting the inlet passage to the outlet passage and a thermostatic valve assembly configured to connect the inlet passage to the piston when the temperature of the hydraulic fluid is below a threshold temperature and connect the inlet passage to the bypass passage when the temperature of the hydraulic fluid is above the threshold temperature.

A rotary hammer includes a housing and a mode selection dial supported in the housing. The mode selection dial includes a cam. The housing supports a motor providing a rotational output. The housing supports a linkage moveable between a first position and a second position in response to engagement by the cam. A loss-of-control detection system measures acceleration of the housing and disables the motor upon the acceleration exceeding an acceleration threshold. The housing supports an operating mode detection system including a magnet and a Hall-effect sensor. The magnet is coupled to the linkage and moveable therewith between a third position corresponding to the first position of the linkage and a fourth position corresponding to the second position of the linkage. The Hall-effect sensor provides an output signal indictive of the position of the magnet. The loss-of-control detection system is selectively disabled based upon the output signal.

A power tool includes a housing, a motor supported by the housing, and a mode selector movable between a plurality of positions, each of the plurality of positions corresponding to one of plurality of operating modes of the power tool. The power tool further includes an operating mode detection system that detects a current operating mode of the power tool and generates an output signal corresponding to the current operating mode, and a loss-of-control detection system that performs protective operation based on an acceleration of the housing. The loss-of-control detection system is enabled or disabled based upon the output signal from the operating mode detection system.