Electric wall socket aperture drilling device - has diamond cutting crown around central drill bit and selective hammer drill operating mode

摘要

The drilling device uses a central drill bit (32) and a driven hollow shaft (14) which has a diamond cutting crown (17) at its front end, fitting around the outside of the drill bit (32), so that the tip of the latter lies in the same plane as the cutting crown (17). The drill bit (32) is selectively acted on by an impact device with an impact hammer (25, 26, 27, 29) contained within the drive hollow shaft (14). ADVANTAGE - Has hammer drill and drill operating modes.