Drilling aid for drilling machine

摘要

The drill holder part (15) acts as a clamp around the drill body and is clamped in position by a bolt (20). The holder is joined to a yoke section (68) with two arms (71,72) which fasten around a clamp piece (74) via a of screw through the arms, allowing the arms to rotate in relation to it. The clamp piece has a central main bore which extends from the downwards through the clamp piece. A second smaller bore (7) joins the main bore to the bottom of the clamp piece. A support wire (16) runs through both bores and at its lower end has a hook piece (37) for locating under the work piece. The main bore has a sleeve (78) with a conical internal bore which accepts a tension bush (81) and stop bush (84) held against the tension bush by a spring (85). At the top end of the spring is a support ring (86) which is screwed into the clamp piece. A stop release bush (89) is located at the bottom of the clamp piece which serves to release the clamp on the cable.