Clamping mechanism for reciprocating dental tool

A reciprocating tool holder assembly, particularly suited for mounting a tool useful in the practice of dentistry, said assembly comprising, in combination, a hollow generally cylindrical tool holder defining therein a tool holder chamber adapted to have a tool inserted therein, means engaging said tool holder to produce reciprocating motion thereof, a plurality of bores formed through the walls of said tool holder and opening into said tool holder chamber, a plurality of generally shperically shaped clamping members, loosely fitted one within each of said bores and configured to partially extend to within said tool holder chamber to effect a radial clamping force against the body located within said chamber, said bores being shaped to limit movement of said clamping members radially inwardly of said bores to prevent said clamping members from passing through said bores into said tool holder chamber while enabling said clamping members to extend partially into said tool holder chamber to engage said tool and apply a radial clamping force thereagainst, a clamping nut adjustably engaged upon said tool holder and having defined thereon conical surface means located to engage said clamping members and adapted to force said clamping members radially inwardly of said bores toward said chamber upon adjustable positioning of said nut relative to said tool holder, and a conically shaped internal abutment surface defined interiorly of said tool holder chamber and adapted to be engaged by a complementary surface of a body placed within said chamber for axially positioning a tool within said chamber, with a tool inserted within said tool holder chamber being axially positioned by said internal abutment surface and have applied thereto a radially directed clamping force by operation of said clamping nut and said clamping members to hold said tool in place during operation of said assembly.