Hand held rotary power tool

A power tool (1,fig.1) includes a motor (22,fig.2) and a power supply (44,fig.2) that are connected by a switch (38,fig.3) disposed in an electrical circuit. The switch controls the on/off state of the motor and is actuated by a switch actuator 50 that serves as a spring element. The switch actuator includes a guide plate 51 supported on the tool's housing (optionally on a shelf 8,fig.5), and a resilient arm 66 that protrudes from the guide plate into an opening in the tool housing. When the switch actuator is in a first position (switched off) relative to the housing, the resilient arm is biased toward an edge of the opening and engages the edge (figs.6,9), preventing inadvertent movement of the switch actuator to the second actuator position (switched on). When the switch actuator is actuated by applying a bi-directional manual force to the resilient arm (pressing the switch into the casing and sliding the switch between positions), the resilient arm is displaced from the edge (figs.7,11), thereby permitting movement of the switch actuator to the second actuator position. The objective of the invention is to reduce the risk of a user accidentally activating the power tool.