GB2422564A

GB2422564A - Twist drill bit

Info

Publication number: GB2422564A
Application number: GB0509881A
Authority: GB
Inventors: Chi-Chin Lin
Original assignee: SHIAO PUO SHI ENTPR CO Ltd
Current assignee: SHIAO PUO SHI ENTPR CO Ltd
Priority date: 2005-01-31
Filing date: 2005-05-16
Publication date: 2006-08-02
Also published as: GB0509881D0; TWM270862U

Abstract

Twist drill bit includes a spur indicating an awl shape disposed at the most front edge of the drill bit; a lead screw disposed below the spur; a fluted land extending from the spur along the lead screw to a head; and a shank connecting to the head with a recessed fluted angle and containing flute(s) for expelling residual chips. Twist drill bit (1) comprises a spur indicating an awl shape disposed at the most front edge of the drill bit; a lead screw (20) disposed below the spur having a taper angle (21); a cylindrical head (30) disposed extending downward from the lead screw; a pair of cutter (40), each contains a blade (41) provided at the lead screw; a fluted land (50) related to a slope extending from the spur along the lead screw to the head; and a shank (60) connecting to the head with a recessed fluted angle (62) and containing flute(s) (61) for expelling residual chips. Each blade extends downward from the lead screw to form a cutting angle (42).

Description

TITLE: TWISTDRILLBIT

BACKGROUND OF ThE INVENTION

(a) Technical Field of the Invention

The present invention is related to a twist drill bit, and more particularly, to one that the drilling point is modified to indicate one point.

(b) Description of the Prior Art

As illustrated in Figs. I (a) and 1(b), a twist drill bit (lOa) of the prior art includes a bit cylindrical lead screw (20a) and body (30a). The body (30a) provides a pair of flutes (40a) and a shank (50a) secured by ajaw of a drill.

The lead screw (20a) of the drill bit (1 Oa) generally is made in conic and the tip indicates a ridge (21 a) where extends a blade (22a) in reverse radius direction and connects to the flute (40a).

A significant resistance is encountered to result in displacement of the drill point when the conic lead screw (20a) of the drill bit (I Oa) enters into a work piece, thus to compromise drill efficiency. Furthermore, the poor design of fluted land fails to effectively expel the residual chips in the drill hole for them to create even greater secondary resistance to the drilling.

Whereas the tip of the lead screw (20a) indicates the ridge (21 a), the ridge (21 a) upon contacting the work piece easily causes the displacement of the positioning of the drilling to further create error to the target drill location.

SUMMARY OF ThE INVENTION

The primary purpose of the present invention is to provide a totally new design and new construction of a twist drill bit that allows turnkey operation using automatic machinery, integrated and mass production at high speed to improve drill accuracy, drilling, heat dissipation and residual chips expelling capabilities.

To achieve the purpose, a spur in the shape of an awl is provided at the most front edge of the bit to secure a precise positioning of the drill hole.

The spur increases heat dissipation capability; a bland and a lead screw increase drilling capability; a fluted land achieves highly efficient heat dissipation and residual chips expelling capabilities.

The foregoing object and summary provide only a brief introduction to the present invention. To fully appreciate these and other objects of the present invention as well as the invention itself, all of which will become apparent to those skilled in the art, the following detailed description of the invention and the claims should be read in conjunction with the accompanying drawings. Throughout the specification and drawings identical reference numerals refer to identical or similar parts.

Many other advantages and features of the present invention will become manifest to those versed in the art upon making reference to the detailed description and the accompanying sheets of drawings in which a preferred structural embodiment incorporating the principles of the present invention is shown by way of illustrative example.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1(a) is a bird's eye view of a drill bit of the prior art.

Fig. 1(b) is a front view of the prior art illustrated in Fig. (la).

Fig. 2 is a perspective view of the present invention.

Fig. 3 is a bird's eye view of the present invention.

Fig. 4 is a front view of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following descriptions are of exemplary embodiments only, and are not intended to limit the scope, applicability or configuration of the invention in any way. Rather, the following description provides a convenient illustration for implementing exemplary embodiments of the invention.

Various changes to the described embodiments may be made in the function and arrangement of the elements described without departing from the scope of the invention as set forth in the appended claims.

Referring to Fig. 2, a drill bit 1 of the present invention includes a spur indicating an awl shape disposed at the most front edge of the drill bit 1; a lead screw 20 disposed below the spur 10 having a taper angle 21 greater than 90 degrees and preferred at 105 degrees for an optimal tapering angle for the drill bit 1; a head 30 is disposed extending downward from the lead screw 20 and made in a cylindrical shape; a pair of cutter 40 each containing a blade 41 provided at the lead screw 20 and each blade 41 extends downward from the lead screw to form a cutting angle 42; a fluted land 50 relates to a slope extending from the spur 10 along the lead screw 20 to the head 30; and a shank 60 connects to the head 30 with a recessed fluted angle 62 and contains one or a plurality flutes 61 for expelling residual chips.

As illustrated in Figs. 3 and 4, the bit I is secured in ajaw of a power tool (not illustrated) to start drilling a work piece. The awl shaped spur 10 accurately drill out a positioning point on the work piece. Both blades 41 from the cutter 40 disposed on the lead screw 20 drill into the work piece.

Meanwhile, both abutted cutting angles 42 from both blades 41 of the cutter 40 to cut deeper, and the fluted land 50 quickly guides the residual chips into those flutes 61 on the shank 60 to the surface of the work piece.

Furthermore, in the process of cutting and drilling, the lead screw 20 of the bit I upon contacting the work piece and revolving into the fluted land 50 provides excellent heat dissipation.

The present invention by improving the flows of displacement of drilling point, slower drilling process on the work piece and insufficient expelling of the residual chips complies with the requirements of applying for a utility pattern; therefore, this application is duly filed accordingly.

It will be understood that each of the elements described above, or two or more together may also find a useful application in other types of methods differing from the type described above.

While certain novel features of this invention have been shown and described and are pointed out in the annexed claim, it is not intended to be limited to the details above, since it will be understood that various omissions, modifications, substitutions and changes in the forms and details of the device illustrated and in its operation can be made by those skilled in the art without departing in any way from the spirit of the present invention.

Claims

I CLAIM: 1. A twist drill bit includes a spur indicating an awl shape

disposed at the most front edge of the drill bit; a lead screw disposed below the spur having a taper angle; a head disposed extending downward from the lead screw and made in a cylindrical shape; a pair of cutter each containing a blade provided at the lead screw and each blade extending downward from the lead screw to form a cutting angle; a fluted land being related to a slope extending from the spur along the lead screw to the head; and a shank connecting to the head with a recessed fluted angle and containing one or a plurality flutes for expelling residual chips.
2. The twist drill bit of Claim 1, wherein the taper angle is greater than degrees.
3. The twist drill bit of Claim 1, a recessed guide angle is provided at where the head is connected to the shank.