Dentist's drill chuck

In a combination of a chuck of the kind having a tapped end section to which a dentistry drill tool is to be fastened by a screw and a utensil for screwing said screw into said tapped end section, the improvement comprising:

• said tapped section of said chuck terminated by an external polygonal head adapted to be engaged stably by a complementary seat of said utensil;
• said screw having a polygonal head;
• said utensil having a pipe wrench section and a substantially U-shaped supporting member defining opposed prongs between which there extends said pipe wrench section rotatable and axially translatable against the bias of a spring, said wrench section being borne by a selected prong of said supporting member whereas the opposite prong has a seat coaxial with the wrench section within which seat the chuck can be engaged, said screw having a polygonal head matching the wrench section, a drill tool being fastened to said chuck by said polygonal head screw by means of operation of the pipe wrench section, the drill tool being thus clamped between the wrench section and the prong of the supporting member;
• said selected prong having a bore formed therethrough and a bushing mounted in said bore, said bushing having an overhanging portion in which said wrench section is mounted, the wrench section extending beyond said overhanging portion by a knob opposite to the wrench section chamber;
• said seat of said opposite prong formed on a resting plane thereof, said resting plane having a gutter-like shape and terminating with a U-section placed between a couple of confronting shoulders, said U-section and said shoulders engaging the polygonal head of the drill tool chuck;
• and
• said opposite prong having a planar abutting surface disposed apart from said seat and exterior of said prongs, said planar abutting surface provided as a support to maintain planar alignment of said chuck with said screw and said wrench section.