Patent ID: 8784015

Claim:
A portable power drill comprising: a housing; a drive motor; a rotative drive spindle configured to carry a drilling implement and being axially displaceable relative to the housing for feeding movements; a coupling for transferring rotational movement from the drive motor to the drive spindle irrespective of axial displacement of the drive spindle; and a feed mechanism for axially displacing the drive spindle; wherein the feed mechanism comprises: a threaded portion of the drive spindle; a nut piece rotative but axially immovable relative to the housing and arranged to cooperate with said threaded portion; and a feed shaft located in parallel with and coupled to the drive motor via a transmission and drivingly connected to said nut piece; wherein said transmission comprises: a belt drive provided with a toothed flexible belt; a first pulley arranged on the drive motor; and a second pulley arranged on the feed shaft; and wherein said first and second pulleys are exchangeable to change a rotation speed of said feed shaft in relation to a speed of the drive motor.