Drive shaft with a coupling arrangement

Claim 1

Drive shaft, connectable for driving purposes to a motor or geared motor, said drive shaft being made of flexible steel wire with a round profile, or flexible steel wire with several concentric layers of wire wound around a core made of flexible steel wire with a round profile and being disposed in a tube of synthetic material or coiled steel wire tightly bound therearound and including a coupling element for attachment of said drive shaft to a tool-shaft of a symmetrically rotating tool provided with a head for milling, polishing or grinding purposes, a tubular housing (6) attached to said tube on the side away from said motor or geared motor, and cylindrical coupling element rotatably disposed in said housing, said drive shaft characterized by a permanent bar magnet (12) secured in the coupling element (7), the rear end of which is firmly attached centrically to the forward end of said drive shaft (1), said coupling element having a front end-face and a hole (17) having a cross-sectional shape compatible with said tool-shaft and in which said tool-shaft cannot turn in the middle thereof running longitudinally therein, and into which said tool-shaft (24) is disposed through an opening in the front of said housing (6), the end part (26) of said tool-shaft corresponding to the cross-sectional shape of said hole (17) and having a flat end-face, which, when in coupled position, sits flat on the smooth pole face (29) of said bar magnet which forms the base of said hole (17), the opening of said hole (17) in the coupling element (7) being funneled away from the edge of said opening, and a piece of piping (19) fitted in the front part of said housing which forms a positioning and guiding bushing for said tool-shaft (24).