Patent ID: 6378623
Filing Date: 2002-04-30
Classification: B25B

Abstract:
A torque control type impact wrench comprising:torque producing means for producing pulsed torque; driving means for driving the torque producing means; a rotating shaft fitted to a predetermined male screw and rotated by the pulsed torque produced from the torque producing means, for screwing the male screw into a predetermined female screw; first setting means for setting an ideal upper limit of the pulsed torque for screwing the male screw into the female screw; second setting means for setting a driving speed at which the driving means drives the torque producing means; first storage means for storing the ideal upper limit of the pulsed torque, which is set by the first setting means, as a first storage value; second storage means for storing the driving speed, which is set by the second setting means, as a second storage value; and control means for causing the driving means to drive the torque producing means at the second storage value and stopping the driving means when the pulsed torque exceeds the first storage value, wherein the control means causes the second storage means to store a value, which is larger than the second storage value, as a new second storage value when the pulsed torque does not reach the first storage value within a given time period after the driving means starts.