Grinding crown, in particular diamond grinding crown

摘要

This annular drill is an abrasive bit (10), in particular a diamond abrasive bit, for masonry installation openings in the dry grinding process. This abrasive bit (10) is a U-shaped body in cross-section which can be releasably connected to an intermediate piece, such as a drill-chuck receptacle (31), for coupling to a drilling machine. In this arrangement, the intermediate piece is mounted in a rotatable and tight manner in a hollow body, and the abrasive bit (10) is provided with a centre drill and with discharge lines for drilling dust which lie in the area of its top side. Connection to a dust extractor is possible in order to draw off the accumulating drillings. According to the invention, the top (14) of the abrasive bit (10) itself has the apertures (17) lying outside its centre. A hood-like collecting device (19) is arranged downstream of these apertures (17) of the abrasive bit (10) in such a way that its bottom area (25) overlaps the top (14) of the abrasive bit (10) all round. A conical centre part (21) with a large receiving space for the drilling dust adjoins the fastening area (25) of the collecting device (19). The peripheral surface of this conical centre part is interrupted at one point for creating an inlet for a connection piece (24). IMAGE