Abstract: An embodiment of a reaction chamber is described that comprises a block of a material comprising a heat source positioned in a central location and a continuous channel comprising an inlet positioned at a first peripheral area of the block and an outlet positioned at a second peripheral area of the block, wherein the channel comprises a serpentine path from the inlet past the centrally located heat source to the outlet.

Abstract: A mode selector mechanism is provided for a rotary power tool for selecting between an impact mode and a drill mode. The power tool includes a housing, a motor oriented in the housing, an input shaft and an output shaft both rotationally mounted in the housing. An impact mechanism connects the input shaft to the output shaft for imparting a rotary impact to the output shaft when the torque load exceeds a predetermined torque capacity of the impact mechanism. A stopping member is shiftable by a user between a first orientation that permits the impact mechanism to operate in the impact mode and a second orientation that prevents a coupler of the impact mechanism from retracting, thus maintaining the connection of the input shaft and the output shaft in the drill mode.

Abstract: A proximity sensor module includes a housing; and a proximity sensor disposed in the housing, wherein the proximity sensor comprises a sensor plate configured to contact inside of the housing such that substantially no gap exists between the sensor plate and the housing. The housing may be a substantially explosion-proof housing. The housing may include two members coupled by a thread engagement, wherein a sensor plate of the proximity sensor is placed off-center with respect to an axis of rotation for the thread engagement.