CONTROL METHOD FOR A POWER DRILL AND A POWER DRILL WITH LOAD CONTROL MEANS

摘要

A control method for a power drill and a power drill relating to the type of power drill having a rotatable and longitudinally displaceable drill spindle (11)and carrying a drilling implement, a power transmission (12) coupling a rotation motor (13) to the drill spindle (11), and a control unit (17) for controlling the operation of the drill spindle (11), wherein the power transmission (12) includes an indicating device(38)for indicating a load magnitude corresponding to the total load transferred by the drill spindle (11) during drilling. An activating device (26) is arranged to activate the indicating device (38) as the load transferred by the drill spindle (11) reaches a predetermined level to thereby accomplish a shifting of the drill spindle operation from a forward directed feeding movement to a reverse retract movement, whereby the drilling implement and/or the object being drilled are prevented from being damaged.