# US 2014/0154022 A1 · Drill head for deep hole cutting

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- Number: US 2014/0154022 A1
- Document ID: US20140154022A1
- Status: Published application
- Kind: A1
- Application number: 14/117,910
- Filed: 2011-05-16
- Published: 2014-06-05
- Earliest claimed: 2011-05-16
- Assignees: botek Präzisionsbohrtechnik GmbH
- Inventors: Takuji Nomura
- Web page: https://patentgrep.com/patent/US20140154022A1

## CPC

- B23B 51/0054: {Drill guiding devices}
- B23B 51/0493: {with exchangeable cutting inserts, e.g. able to be clamped}
- B23B 51/0486: {with lubricating or cooling equipment (B23B51/042 takes precedence)}
- B23B 51/063: {Deep hole drills, e.g. ejector drills}
- B23B 2240/08: Brazed connections
- B23B 2251/44: Margins, i.e. the narrow portion of the land which is not cut away to provide clearance on the circumferential surface
- B23B 2251/56: Guiding pads
- Y10T 408/5586: Engaging surface subsequent to tool-action on that surface
- B23B: TURNING; BORING (arrangements for copying or controlling B23Q)
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

A drill head for deep-hole drilling includes cutting blade tips brazed to cutting chip discharge ports opened on a head distal end surface, guide pads mounted on a plurality of positions of the circumferential surface at the head distal end side, and a hollow inside portion made into a cutting chip discharge passage communicating with the cutting chip discharge ports. A guide pad portion having an arc surf ace that slide-contacts with the inner circumference of a cutting hole is formed on the outer end surface of the circumferential portion cutting blade tip.

## Claims

### Claim 1

A drill head for deep-hole drilling including one or a plurality of cutting blade tips mounted by brazing to face a cutting chip discharge port opened on a head distal end surface, guide pads mounted on a plurality of positions of a circumferential surface at the head distal end side, and a hollow inside portion made into a cutting chip discharge passage communicating with the cutting chip discharge port, wherein
a guide pad portion having an arc surface that slide-contacts with the inner circumference of a cutting hole is formed on the outer end surface of the cutting blade tip taking charge of cutting a circumferential side.

### Claim 2 (depends on 1)

The drill head for deep-hole drilling according to claim 1, wherein the blade point side of the cutting blade tip taking charge of cutting a circumferential side is set upward, a margin portion facing the front edge in a cutting rotation direction and a flank face to be spaced apart from the inner circumference of the cutting hole along the rear side in the cutting rotation direction from the margin portion are formed at an upper portion side of the outer end surface of the cutting blade tip, and the guide pad portion is formed at a lower portion side of the outer end surface of the cutting blade tip.

### Claim 3 (depends on 2)

The drill head for deep-hole drilling according to claim 2, wherein the margin portion and the guide pad portion form a continuous arc surface.

### Claim 4 (depends on 2)

The drill head for deep-hole drilling according to claim 2, wherein the margin portion and the guide pad portion are separated from each other by a groove portion.

### Claim 5 (depends on 1)

The drill head for deep-hole drilling according to claim 1, wherein the guide pads are mounted by brazing on a position radially opposite to the cutting blade tip taking charge of cutting a circumferential side and an intermediate position in the middle of a route leading to a mounting portion of the cutting blade tip in the cutting rotation direction from the aforementioned position.

### Claim 6 (depends on 1)

The drill head for deep-hole drilling according to claim 1, wherein the cutting blade tip is fitted to and brazed to a mounting seat recessed on the head distal end side.

### Claim 7 (depends on 1)

The drill head for deep-hole drilling according to claim 1, wherein a stepped chip breaker is formed on the front surface of the cutting blade tip.

### Claim 8 (depends on 1)

The drill head for deep-hole drilling according to claim 1, wherein the cutting blade tip is made of a super hard material such as cemented carbide and cermet, etc.

### Claim 9 (depends on 1)

The drill head for deep-hole drilling according to claim 1, wherein the guide pads are made of a super hard material such as cemented carbide and cermet, etc.

### Claim 10 (depends on 1)

The drill head for deep-hole drilling according to claim 1, wherein respective key ways for twisting operation are formed in radially opposed positions nearer the proximal end side than the mounting positions of the guide pads mounted on a plurality of positions on the circumferential surface at the head distal end side.