Drill tool
OwnerArtur Fischerinventor
Life of this patent
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Abstract
A tool for drilling a cylindrical hole with an enlarged end undercut portion comprises a shank with cutting edges and a drill collet screwed to the shank by a knuckle thread. The collet is provided with a stop collar having a semispherically-shaped face supported in a matingly configurated recess provided in a stop plate so as to form a swivel bearing. A portion of the collet is closed by a bell connected to the stop plate and formed with a central hole to receive the shank of the tool.
Claims10
A tool for drilling holes with undercut enlarged portions in a support structure, comprising an enlongated drill shank having an axis of rotation, a drill bit at one end of said drill shank and having cutting edges extended radially outwardly of said drill shank;
- a drill collet at the other end of said drill shank, said drill collet being provided with a stop collar being of a substantially semispherical configuration;
- a stop plate being formed with a recess supporting said stop collar and being shaped so as to matingly complement the configuration of said stop collar thus forming therewith a swivel bearing;
- said drill shank being screwed into said drill collet;
- and a drill bell connectable to said stop plate and having a central through bore to receive said drill collet, said cutting edges being operative for forming a cylindrical hole in said support structure when the tool is axially advanced within said structure and for forming an enlarged undercut portion of the hole when a swiveling movement is imparted to the tool.
Dependencies are inferred from the claim text.