| 摘要 |
A special clamping block in combination with a screw clamp fitted with a pair of bores, one bore provided on the top face of the screw clamp and the other bore provided on the outer side face of the screw clamp, the special clamping block having a clamping ring at the end thereof adapted to receive the neck of an electrical hand drill at said end and having a projection plug which fits either into the top face bore of the screw clamp or the outer side face bore whereby the drill may be positioned to the side of the screw clamp or over the top surface thereof. In a preferred embodiment a molded one piece clamping block is formed with supporting struts to strengthen the structure and adjustable clamping projections or fingers are provided at the inner edge of the clamping ring closest to the projecting plug which permit tightening of the clamping ring by tightening screws passing perpendicularly through said fingers to close the slit therebetween or to open the slit by loosening the screws to permit removal of the electrical drill. |
