| 摘要 |
The invention relates to a method of and apparatus for making an undercut in a drilled hole in a fixed base, such as concrete, masonry or the like. The shank of a milling cutter is supported and held eccentrically in the drill hole by means of a supporting sleeve which can be extended into the drill hole when the milling cutter is running. The supporting sleeve has an outside diameter slightly less than the diameter of the cylindrical drill hole so as to fit therein, and is formed with a receptacle groove extending longitudinally of the sleeve and opening at the periphery of the sleeve. The shank of the milling cutter is positioned in the groove, the axis of which is parallel to but radially outwardly spaced from the coaxial axes of the drill hole and sleeve. Rotation of the sleeve can be by a hand wheel interconnected to the sleeve, with the milling cutter rotating with the sleeve to form the undercut. |
