Patent ID: 8678106
Filing Date: 2014-03-25
Classification: B25B

Abstract:
1. A rotary impact tool for use with a motor, comprising: a hammer configured to rotate by receiving a rotational force of the motor; an anvil configured to rotate by receiving a rotational force of the hammer; an end tool attached to the anvil, such that if a torque of a value not less than a predetermined value is applied to the anvil from the outside via the end tool, then the hammer is disengaged from the anvil to rotate idle and applies an impact to the anvil in a rotational direction after rotating idle by a predetermined angle; an impact detection device configured to detect impacts; a main switch configured to adjust the rotating speed of the motor according to a pulling amount of a trigger; and a speed switching device configured to switch the rotational speed of the motor between a low speed mode and a high speed mode, wherein both in the low speed mode and the high speed mode, the rotational speed of the motor is adjusted according to the pulling amount of the trigger; wherein the rotational speed in the high speed mode is higher than the rotational speed in the low speed mode when the trigger is pulled by the same amount; and wherein if the impact detection device detects start of impact during rotation of the anvil in a tightening direction while the motor rotates in the high speed mode, then the speed switching device switches the high speed mode to the low speed mode.