Drill steel and its manufacture
AssigneeDaltron Forge (Pty) Ltd
InventorDale Robert Cox
Life of this patent
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Abstract
A drill steel includes a metal rod with an end to fit within a chuck of a drilling machine, and an integrally formed collar provided along the length of the metal rod. A ferrule is fastened on the metal rod adjacent the integrally formed collar on the side of the end of the metal rod. The ferrule forms a stop that prevents the drill steel from moving too far into the chuck.
Claims20
A drill steel comprising a metal rod with a first end thereof to fit within a chuck of a drilling machine, wherein an integrally formed collar is provided along a length of the metal rod and a ferrule is fastened on the metal rod adjacent the integrally formed collar on the side of the first end of the metal rod, the ferrule forming a stop that prevents the drill steel from moving too far into the chuck.
A method of manufacturing a drill steel, the method comprising:
- connecting at least one electrode of an electric circuit to a metal rod in a position spaced from a first end of the metal rod;
- contacting the first end of the metal rod against an anvil within a die, the anvil being connected to the electric circuit, and the die having a main elongate chamber with a consistent width along its length;
- energizing the electric circuit so that electric current flows between the electrode and the anvil so as to heat a section of the metal rod between the electrode and the first end;
- applying a force to compress the first end against the anvil such that the first end is upset forged within the die;
- permitting heated material of the upset forged first end to move towards a mouth of the die and at least partly out of the main elongate chamber so as to widen and form an integral collar;
- the force being applied continuously and the electric circuit being energized for at least 30 seconds;
- allowing the upset first end to cool;
- and
- fastening a ferrule on the metal rod adjacent the collar on the side of the first end of the metal rod.
Dependencies are inferred from the claim text.