U.S. patent application number 11/703004 was filed with the patent office on 2007-08-23 for rock drilling head.
This patent application is currently assigned to Hilti Aktiengesellschaft. Invention is credited to Uwe Bohn, Kay Heemann, Wolfgang Ludwig.
Application Number | 20070193784 11/703004 |
Document ID | / |
Family ID | 38288551 |
Filed Date | 2007-08-23 |
United States Patent
Application |
20070193784 |
Kind Code |
A1 |
Heemann; Kay ; et
al. |
August 23, 2007 |
Rock drilling head
Abstract
A rock drilling head (1) with a drilling diameter (D) between 25
mm and 60 mm and formed of no more than five separate parts, has at
least one rinsing channel (2) formed in the outer surface (3) of
the drilling head and expanding from the outer surface (3) inward
in form of a nozzle, the rinsing channel having a diameter (S)
amounting to between 1/20 and 1/5 of the drilling diameter (D).
Inventors: |
Heemann; Kay; (Kaufering,
DE) ; Ludwig; Wolfgang; (Klosterlechfeld, DE)
; Bohn; Uwe; (Kissing, DE) |
Correspondence
Address: |
ABELMAN, FRAYNE & SCHWAB
666 THIRD AVENUE, 10TH FLOOR
NEW YORK
NY
10017
US
|
Assignee: |
Hilti Aktiengesellschaft
|
Family ID: |
38288551 |
Appl. No.: |
11/703004 |
Filed: |
February 6, 2007 |
Current U.S.
Class: |
175/393 ;
175/339 |
Current CPC
Class: |
B23B 51/06 20130101;
B23B 2226/75 20130101; B23B 2270/62 20130101; E21B 10/38 20130101;
B28D 1/146 20130101 |
Class at
Publication: |
175/393 ;
175/339 |
International
Class: |
E21B 10/60 20060101
E21B010/60 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 20, 2006 |
DE |
10 2006 000 081.1 |
Claims
1. A rock drilling head having a drilling diameter (D) between 25
mm and 60 mm and formed of no more than five separate parts,
comprising an outer surface (3); and at least one rinsing channel
(2) formed in the outer surface (3) and expanding from the outer
surface (3) inward in form of a nozzle, and having a diameter (S)
amounting to between 1/20 and 1/5 of the drilling diameter (D).
2. A rock drilling head according to claim 1, wherein the rinsing
channel (2) expands with a cone angle (.alpha.) between 3.degree.
and 30.degree..
3. A rock drilling head according to claim 1, comprising a further
rinsing channel (2).
4. A rock drilling head according to claim 1, comprising a base
member (4).
5. A rock drilling head according to claim 4, wherein the base
member (4) is formed as a steel casting.
6. A rock drilling head according to claim 4, further comprising a
hard material insert (5) extending diametrically over the drilling
diameter (D) and secured in a groove (6) formed in the base member
(4).
7. A rock drilling head according to claim 1, comprising only one
base member (4), and only one hard material insert (5) extending
diametrically over the drilling diameter (D) and secured in a
groove (6) formed in the one base member (4).
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a rock drilling head
provided with hard material means and having rinsing channels and
designed for use, in particular, in blast shot drills or injection
self-drilling anchors.
[0003] 2. Description of the Prior Art
[0004] Such mass-produced drilling heads, to which the present
invention is limited, have, at a drilling diameter between 25 mm
and 60 mm, a small degree of complexity. So the number of separate
parts, such as hard material inserts that form cutters, is limited,
for manufacturing reasons, to a small number, maximum five.
Dependent on the type of a to-be-drilled underground, these rock
drilling heads are operated in a wet drilling process with low (5
to 30 bar) water pressures or in a dry drilling process with
aspiration of drillings (with suction pressure 0.3 to 0.7 bar),
with the rinsing or suction taking place through the rinsing
channels having a rinsing channel diameter between 1/20 and 1/5 of
the drilling diameter.
[0005] U.S. Pat. No. 4,185,708 discloses such a rock drilling head
equipped with hard material cutter means and having cylindrical
rinsing channels formed directly of the drilling head base body and
having different channel diameters.
[0006] U.S. Pat. No. 4,540,056 discloses a rock drilling head
equipped with hard material cutter means with a drilling diameter
of 2.5 cm replaceably secured in head support in which special high
pressure nozzles, which are formed as screw-in inserts, are screwed
in cylindrical openings. The opening diameter of the high-pressure
nozzles is too narrow to provide for removal of drillings at a dry
drilling or to obtain, at wet drilling with a low water pressure, a
necessary rinsing medium flow.
[0007] An object of the present invention is to provide a rock
drilling head equipped with hard material cutter means, having a
drilling diameter between 25 mm and 60 mm, rinsing channels
suitable for both wet and dry drilling, and suitable for mass
production.
SUMMARY OF THE INVENTION
[0008] This and other objects of the present invention, which will
become apparent hereinafter, are achieved by providing a rock
drilling head having a drilling diameter between 25 mm and 60 mm
formed of no more than five separate parts and including at least
one rinsing channel formed in the outer surface of the drilling
head and expanding from the outer surface inward in the form of a
nozzle, and having a diameter(s) amounting to between 1/20 and 1/5
of the drilling diameter.
[0009] With a rinsing channel that constantly expands inwardly in
the form of a nozzle (along the flow and having a concave, conical,
or convex profile and being, in flow cross-section, rotationally
symmetrical, completely symmetrical, and asymmetrical), the
drillings, which are aspirated from outside in the rinsing channel
in the dry drilling process, cannot be detained there because the
cross-section of the rinsing channel constantly widens inward.
During wet drilling with low-pressure rinsing means, with the flow
directed from the interior outwardly, a high flow velocity is
achieved in the narrowing outer region of the rinsing channel, and
the drillings, which are accumulated in the rinsing channel, are
subjected to the dynamic pressure of the rinsing medium flow and
are carried along.
[0010] Advantageously, the rinsing channel expands from the outer
surface with a cone angle between 3.degree. and 30.degree., which
ensures a sufficiently large widening of the cross-section
inwardly.
[0011] Advantageously, there are provided two rinsing channels
which are advantageously arranged symmetrically with respect to the
drilling axis, so that with blocking of one of the rinsing
channels, at least one other rinsing channel is available.
[0012] Advantageously, the rock drilling head is formed of a base
member formed as a casting, with the rinsing channel being
advantageously formed during casting.
[0013] Advantageously, the rock drilling head is formed of only one
base member and only one hard material insert extending
diametrically over the drilling diameter and secured in a groove
formed in the one base member. This ensures an economical
production of the rock drilling head with few process steps.
[0014] The novel features of the present invention which are
considered as characteristic for the invention, are set forth in
the appended claims. The invention itself, however, both as to its
construction and its mode of operation, together with additional
advantages and objects thereof, will be best understood from the
following detailed description of preferred embodiment, when read
with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The drawings show:
[0016] FIG. 1 a longitudinal cross-sectional view of a rock
drilling head according to the present invention along line I-I in
FIG. 2 in three planes; and
[0017] FIG. 2 a plan view of the rock drilling head according to
the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0018] A drilling head 1 for a rock drill, which is shown in FIGS.
1-2, has drilling diameter D of 35 mm and two rinsing channels 2
located on opposite sides of a drilling head axis A. The rinsing
channels 2 have a rinsing channel diameter S at an outer surface 3
and equal to about 1/10 of the drilling diameter D. The rinsing
channels 2 expand conically inward from the outer surface 3 in form
of a nozzle with a cone angle .alpha. of 20.degree. that constantly
diminishes further inward. The drilling head 1 is formed of exactly
two separate parts, a base member 4 of steel cashing and a hard
material insert 5 secured in a groove 6 of the base member 4. The
hard material insert 5 extends diametrically over the drilling
diameter D and forms drilling cutters 7,
[0019] Though the present invention was shown and described with
references to the preferred embodiment, such is merely illustrative
of the present invention and is not to be construed as a limitation
thereof and various modifications of the present invention will be
apparent to those skilled in the art. It is therefore not intended
that the present invention be limited to the disclosed embodiment
or details thereof, and the present invention includes all
variations and/or alternative embodiments within the spirit and
scope of the present invention as defined by the appended
claims.
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