U.S. patent application number 12/291902 was filed with the patent office on 2009-06-04 for self-drilling connection anchor.
This patent application is currently assigned to Hilti Aktiengesellschaft. Invention is credited to Michael Bayerl, Kay Heemann, Wolfgang Ludwig, Kolja Wieczorek.
Application Number | 20090142142 12/291902 |
Document ID | / |
Family ID | 40394054 |
Filed Date | 2009-06-04 |
United States Patent
Application |
20090142142 |
Kind Code |
A1 |
Bayerl; Michael ; et
al. |
June 4, 2009 |
Self-drilling connection anchor
Abstract
A self-drilling connection anchor (10) includes an anchor tube
(11), a drilling head (13) provided at the first end (12) of the
anchor tube (11), an inner tube (15) arranged in the anchor tube
(11) and having an interior space (16) for receiving an ejectable
mass (30), a first axial, with respect to the longitudinal axis (L)
defined by the anchor tube, opening (18) provided in a region of
the second free end (14) that communicates with the interior space
(16) of the inner tube (15), at least one outlet opening (20)
provided in a region of the drilling head (13), and at least one
second radial, with respect to the longitudinal axis (L), opening
(19) provided in the region of the free second end (14) and
communicating with the at least one outlet opening (20) via an
intermediate space (17) formed between the anchor tube (11) and the
inner tube (15).
Inventors: |
Bayerl; Michael; (Tuerkheim,
DE) ; Ludwig; Wolfgang; (Zaisertshofen, DE) ;
Wieczorek; Kolja; (Landsberg, DE) ; Heemann; Kay;
(Kaufering, DE) |
Correspondence
Address: |
ABELMAN, FRAYNE & SCHWAB
666 THIRD AVENUE, 10TH FLOOR
NEW YORK
NY
10017
US
|
Assignee: |
Hilti Aktiengesellschaft
|
Family ID: |
40394054 |
Appl. No.: |
12/291902 |
Filed: |
November 13, 2008 |
Current U.S.
Class: |
405/259.5 |
Current CPC
Class: |
F16B 13/143 20130101;
E21D 21/0033 20130101; E21D 21/0053 20160101; F16B 13/003 20130101;
E21D 20/02 20130101 |
Class at
Publication: |
405/259.5 |
International
Class: |
E21D 20/00 20060101
E21D020/00 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 30, 2007 |
DE |
10 2007 057 763.1 |
Claims
1. A self-drilling connection anchor (10) for use in mining and
tunneling, comprising an anchor tube (11) defining a longitudinal
axis (L) and having a first end (12) and a free second end (14); a
drilling head (13) provided at the first end (12); an inner tube
(15) arranged in the anchor tube (11) and having an interior space
(16) for receiving an ejectable mass (30); a first axial, with
respect to the longitudinal axis (L), opening (18) provided in a
region of the second free end (14) that communicates with the
interior space (16) of the inner tube (15); at least one outlet
opening (20) provided in a region of the drilling head (13); and at
least one second radial, with respect to the longitudinal axis (L),
opening (19) provided in the region of the free second end (14) of
the anchor tube 11 and communicating with the at least one outlet
opening (20) via an intermediate space (17) formed between the
anchor tube (11) and the inner tube (15).
2. A connection anchor according to claim 1, comprising two
opposite radial second openings (19).
3. A connection anchor according to claim 1, wherein the at least
one second radial opening (19) is provided in the anchor tube
(11).
4. A connection anchor according to claim 1, wherein the at least
one radial second opening (19) is spaced from the free second end
(14) of the anchor tube (11) by a distance (A) corresponding to
from 0.5 to 2 times of an anchor tube diameter (D).
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a self-drilling connection
anchor including an anchor tube having a first end and a free
second end, a drilling head provided at the first end, an inner
tube arranged in the anchor tube and having an interior space for
receiving an ejectable mass, a first axial, with respect to the
longitudinal axis of the anchor, opening provided in a region of
the second free end of the anchor tube and which communicates with
the interior space of the inner tube, and at least one outlet
opening provided in a region of the drilling head.
[0003] 2. Description of the Prior Art
[0004] Self-drilling anchors of the type described above are used
in mining and tunneling where they serve for securing hollow spaces
such as tunnels, galleries, and the like. During formation of
hollow spaces, mechanical characteristics and in particular the
carrying capacity of rock layers are reduced. These rock layers are
anchored to and are, thereby, are secured to further, remote,
undamaged rock layers with the connection anchors.
[0005] The setting process of the known connection anchors is
carried out in two steps. In the first step, a connection anchor is
drilled in the rock formation with a drilling tool. Stone, which is
produced and crushed by the drilling head of the drill anchor which
is provided a the boring direction-side end of the anchor, is
removed through outlet openings, which are provided in a region of
the drilling head, and the intermediate space between the bore wall
and the outer circumference of the connection anchor. During a wet
drilling process, water is fed in the setting direction, and the
removed and crushed stone is flushed out. During a dry drilling
process, the removed and crushed stone is aspirated. In the second
step, from the side of the connection anchor remote from the
setting direction side, a chemical mass is ejected in the direction
of the bore bottom with a press-out mechanism. The mortar mass,
which is located in the connection anchor, is thereby brought in
the bore from the connection anchor through the outlet opening and
the drilling head and is distributed in the intermediate space
between the bore wall and the outer circumference of the anchor
tube.
[0006] German Publication DE 103 36 043 A1 discloses a
self-drilling connection anchor of the type discussed above. The
disclosed connection anchor has an anchor tube at the first end of
which a drilling head is provided, and a second free end. In the
anchor tube, an inner tube is arranged. Between the inner tube and
the anchor tube, there is provided an intermediate space extending
along the longitudinal axis of the anchor tube at least in some
regions and formed as an annular gap. The intermediate space
provides for feeding of water during a wet drilling process. In the
drilling head, to this end, outer openings are provided and which
communicate with the intermediate space and which are connectable
with the interior space of the inner tube. In the interior space,
an ejectable mass, which is packed in a foil bag, is located. The
chemical mass can be delivered through the outlet openings in the
drilling head. At the second, free end of the anchor tube, there is
provided a first opening that extends along the longitudinal axis
and communicates with the intermediate space and the interior space
of the inner tube.
[0007] An object of the present invention is to further improve a
self-drilling connection anchor described in the German Publication
DE 103 36 043 A1.
SUMMARY OF THE INVENTION
[0008] This and other objects of the present invention, which will
become apparent hereinafter, are achieved by providing at least one
second, radial, with respect to the longitudinal axis, opening in
the region of the free second end which communicates with at least
one outlet opening via an intermediate space formed between the
anchor tube and the inner tube.
[0009] By separation of the access to the intermediate space, on
one hand, from the access to the interior space of the inner tube,
on the other hand, crossing of the fed flushing water and the
advanced press-out means can be prevented. Separate feeds can be
provided at the axial, first opening and the at least one radial,
second opening. Thereby, conventional drill drive motors with
central flushing water feeding in which no second loop for a
high-pressure press-out media is available, can be used.
[0010] Advantageously, there are provided two opposite radial,
second openings whereby a sufficient flushing water supply is
insured when the connection anchor rotates.
[0011] Advantageously, the at least one radial, second opening is
provided in the anchor tube. This insures a good access to the
radial, second opening from outside and that it opens directly in
the intermediate space.
[0012] It is further advantageous when the at least one radial,
second opening is spaced from the free second end of the anchor
tube by a distance corresponding to from 0.5 to 2 times of an
anchor tube diameter. Thereby, it is achieved that common flushing
water systems are used simultaneously with common drill motors with
the central water feeding.
[0013] 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
[0014] In the drawings:
[0015] Single FIGURE shows a longitudinal cross-sectional view of a
self-drilling connection anchor according to the present
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0016] A self-drilling connection anchor 10 according to the
present invention, which is shown in the FIGURE, includes a steel
anchor tube 11 and an inner tube 15 which is formed of steel or a
plastic material and is arranged in the anchor tube 11. In the
interior space 16 of the inner tube 15, there is arranged an
ejectable mass 30 such as one-or multi-component chemical mass and
which is packed in a foil bag 31. The anchor tube 11 has a first
end 12 with a drilling head 13 inserted therein, and a free second
end 14. The anchor tube 11 defines a longitudinal axis L of the
connection anchor 10. A first centering element 24 and a second
centering element 25 axially and radially retain the inner tube 15
in the anchor tube 11, so that the inner tube 15 can be guided
coaxially with respect to longitudinal axis L.
[0017] In the region of the free second end 14 of the anchor tube
11, there is provided an axial, with respect to the longitudinal
axis L, first opening 18 that communicates with the interior space
16 of the inner tube 15. Through this first opening 18, a pressure
medium (first arrow 21), e.g., water can be fed under pressure in
the interior space 16, whereby the foil bag 31, which is located in
the inner tube 15, is ejected by a press-out member 33 displaceable
in the inner tube 15 between the axial first opening 18 and the
foil bag. The mass 30, which is contained in the foil bag 31, is
displaced through a mixing member 32, whereby the components of the
mass 30 intermix. The intermixed mass 30 can then be displaced in
the direction of the second arrow 22 from the inner tube 15 or the
mixing member 22 into the drilling head 13 and further through
outlet opening 20, which are provided in the drilling head 13, into
an outer space that surrounds the connection anchor 10.
[0018] The centering element 24, 25 so position the inner tube 15
in the anchor tube 11 that an intermediate space 17 in form of an
annular gap is formed between the anchor tube 11 and the inner tube
15. In the region of the free second end of the anchor tube 11,
there are provided, in the anchor tube 11, two, opposite, with
respect to the longitudinal axis L, radial openings 19. The radial
openings 19 communicate with outlet openings 20 formed in the
drilling head 13 via the intermediate space 17. The intermediate
space 17 provides for feeding water in case of a wet drilling
process. The water can flow through the radial second openings 19
into the intermediate space 17 (third arrow 23) and, finally,
through the outlet openings 20 in the outer space of the connection
anchor 10.
[0019] The radial second openings 19 are preferably axially spaced
by a distance A from the free second end 14 of the anchor tube 11.
The distance A corresponds to form 0.5 to 2 times of the diameter D
of the anchor tube 11.
[0020] It should be clear that the outlet openings 20, the
intermediate space 17, and the radial second openings 19 can be
used for aspirating bore dust during a dry drilling process.
[0021] 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.
* * * * *