Twist drill
AssigneeHilti Aktiengesellschaft
InventorsRobert S. Saitta, Troy D. Wells, Christian Putzi
Life of this patent
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Abstract
A twist drill including a spiral-forming hollow shaft (3) having a spiral-shaped inner surface, and drilling head(5) and shank (6) connected with the shaft (3) at its opposite ends, respectively; and a method for forming such a twist drill.
Claims14
A twist drill, comprising a hollow shaft forming, at least partially, a spiral (2) and having a spiral-shaped inner surface;
- a drilling head (5) provided at one end of the shaft (3) and having a cutting bit (4) formed of a hard material;
- and a shank for securing the twist drill in a hand-held tool for joint rotation therewith and with a possibility of a limited axial displacement therein.
A method of manufacturing of a twist drill including a hollow shaft forming, at least partially, a spiral (2) and having a spiral-shaped inner surface, a drilling head(s) provided at one end of the shaft (3) and having a cutting bit (4) formed of a hard material, and a shank for securing the twist drill in a handheld tool for joint rotation therewith and with a possibility of a limited axial displacement therein, the method comprising the steps of:
- shaping a tubular blank formed of one of metal and metal alloy to form thereon outer and inner spirals (2);
- cutting the blank provided with the outer and inner spiral to a predetermined length to form the shaft (3);
- and
- fixedly connecting the shaft (3), at opposite ends thereof, with separately formed drilling head and shank (6), respectively.
Dependencies are inferred from the claim text.