U.S. patent application number 16/660230 was filed with the patent office on 2020-05-07 for rod section of an earth drilling string.
The applicant listed for this patent is TRACTO-TECHNIK GMBH & CO. KG. Invention is credited to Tobias Klein, Dieter Wurm.
Application Number | 20200141191 16/660230 |
Document ID | / |
Family ID | 67998266 |
Filed Date | 2020-05-07 |
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United States Patent
Application |
20200141191 |
Kind Code |
A1 |
Wurm; Dieter ; et
al. |
May 7, 2020 |
ROD SECTION OF AN EARTH DRILLING STRING
Abstract
A rod section of a ground drilling rod, wherein the rod section
is configured at its end as a plug connection and comprises at one
end (a) a connection plug or (b) a connection socket, wherein the
connection plug on the outside or the connection socket on the
inside comprises nonround segments along a cross section, wherein
the cross section is constant in configuration.
Inventors: |
Wurm; Dieter; (Kirchhundem,
DE) ; Klein; Tobias; (Lennestadt, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
TRACTO-TECHNIK GMBH & CO. KG |
Lennestadt |
|
DE |
|
|
Family ID: |
67998266 |
Appl. No.: |
16/660230 |
Filed: |
October 22, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
E21B 17/03 20130101;
E21B 17/046 20130101; E21B 17/028 20130101 |
International
Class: |
E21B 17/046 20060101
E21B017/046; E21B 17/02 20060101 E21B017/02 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 31, 2018 |
DE |
102018008533.4 |
Claims
1. A rod section of a ground drilling rod, wherein the rod section
is configured at its end as a plug connection and comprises at one
end: (a) a connection plug or (b) a connection socket, wherein the
connection plug on an outer surface thereof, or the connection
socket on an inner surface thereof, comprises nonround segments
along a cross section, wherein the cross section is constant in
configuration.
2. The rod section according to claim 1, wherein various nonround
segments are formed.
3. The rod section according to claim 2, wherein the various
nonround segments alternate along the circumference.
4. The rod section according to claim 1, wherein the nonround
segments extend for a length of 20 mm to 120 mm in the longitudinal
extension of the rod section.
5. The rod section according to claim 1, wherein an insertion
segment is formed at the entrance side to the nonround
segments.
6. The rod section according to claim 1, wherein inside the rod
section there is present a plug connection for an electrical
connection configured coaxially to the connection socket or
connection plug.
7. A driving element for driving a ground drilling rod into the
ground, being configured to engage with a rod section, wherein the
driving element engaging with the rod section is configured: (a) as
a connection plug, having on the outside a cross section with
nonround segment; or (b) as a connection socket, having on the
inside a cross section with nonround segments, while the cross
section is constant.
8. The driving element according to claim 7, wherein various
nonround segments are formed.
9. The driving element according to claim 8, wherein the segments
alternate along the circumference.
10. The driving element according to claim 7, wherein the nonround
segments extend for a length of 20 mm to 80 mm in the longitudinal
extension of the driving element.
11. The driving element according to claim 7, wherein an insertion
segment is formed at the entrance side to the nonround
segments.
12. The driving element according to claim 7, wherein inside the
driving element there is present a plug connection in the form of
an electrical connection plug or an electrical connection socket
for an electrical connection.
13. The driving element according to claim 12, wherein the plug
connection is oriented coaxially to the connection socket or the
connection plug.
14. A rod section system comprising two or more rod sections
according to claim 1.
15. A ground drilling device comprising a driving element according
to claim 7.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority pursuant to 35 U.S.C.
119(a)-(d) to German Patent Application No. DE 102018008533.4 filed
Oct. 31, 2018, the entire contents of which are incorporated herein
by reference for all purposes.
FIELD OF THE INVENTION
[0002] The invention relates to a rod section of a ground drilling
rod, a driving element for driving a ground drilling rod into the
ground, a rod section system and a ground drilling device.
BACKGROUND
[0003] During rod-based drilling in the ground, especially to
produce so-called horizontal boreholes, which may run substantially
parallel or at a relative slight angle of inclination to the ground
surface, a drill head is advanced by means of a drilling rod by a
drilling device situated on the ground surface or in a construction
pit. The drill rods used in this case usually consist of individual
rod sections which are joined together and which are mounted
gradually on the rear end of the already drilled drilling rod and
connected to it.
[0004] Various designs are known for connecting the rod sections
together. Thus, the rod sections may be connected by means of a
thread connection and/or a plug connection.
[0005] It is known from DE 10 2011 010 958 A1 how to provide a
possibility for connecting two rod sections of a drilling rod which
combines the benefits of the thread connections and the axial plug
connections known in the prior art. This describes a plug
connection which--similar to a thread connection--is based on
spiral projections/grooves extending on a circular-shaped threaded
plug or in a corresponding threaded socket, the projections/grooves
being designed so that the characteristic self-locking of a
threaded connection does not occur.
[0006] Starting from this prior art, the problem which the
invention proposes to solve is to indicate an improved plug
connection for a drilling rod, especially a rod section, which is
in particular more simple in its construction.
SUMMARY
[0007] The invention is based on the idea of indicating a
possibility of connecting two rod sections of a drilling rod and/or
a rod section to a driving element and/or a further element of the
drilling rod, based on nonround segments of a constant cross
section.
[0008] The invention creates a rod section of a ground drilling
rod, wherein the rod section is configured at its end to form a
plug connection and comprises at one end (a) a connection plug or
(b) a connection socket. The connection plug on the outside or the
connection socket on the inside comprises nonround segments along a
cross section. The cross section is constant in configuration.
[0009] The term "rod section" in the sense of the invention
comprises an element extending along a longitudinal axis, which may
be part of a ground drilling rod or a drill string for the soil.
The rod section may be configured as an element with an assigned
function (transmitter housing, drilling tool, or the like) arranged
at the front in the drill string or as an element merely
lengthening the drill string as a "normal" rod section. The rod
section may comprise mechanical ducts, such as for drilling fluid,
electrical cables, electrical elements and/or electronic elements.
The rod section may have a special function in the ground drilling
rod, for example, it may be designed as a transmitter housing.
[0010] A rod section may comprise a first end with a connection
plug or a connection socket as described. The rod section moreover
may comprise a second end, at a distance from the first end, which
usually comprises the other element of the pair of the plug
connection. The rod section, moreover, may have a center line
extending from the first end to the second end. The cross section
of the connection plug or the connection socket may for example be
a cross section perpendicular to the center line of the rod
section.
[0011] The rod section in the sense of the specification may also
be in particular a dual-tube rod section, in which both a so-called
inner rod and a so-called outer rod are present. In such a
dual-tube rod assembly, a drill head may additionally be driven in
rotation via the inner rod from a driving device situated on the
ground surface or in a construction pit, which also ensures the
advancement of the drill head. The inner rod may be mounted for
this purpose rotatably inside the outer rod of the dual-tube rod.
The outer rod in a dual-tube rod assembly must either not rotate at
all or only rotate with a slight speed. The rotations of the outer
rod and the inner rod may occur interpedently of each other. A
dual-tube rod assembly is especially suited to a rock drilling
device, where the wear on the drill string is kept within bounds,
since the outer rod coming into contact with the rock wall of the
borehole can be advanced with no rotation or only slight speed
along the rock wall of the borehole, while the inner rod driven at
higher speed can be mounted in the outer rod, reducing the wear.
The design of nonround segments may be provided in particular for
the connection of the inner rod sections. Nonround segments may
also be provided for the connection of the outer rod sections, but
it is also possible to select a different kind of connection for
the outer rod sections.
[0012] The term "ground drilling tool" encompasses a drill head
arranged at the front end of the ground drilling rod or drill
string, in which moving parts may be provided, but it may also be
provided that the ground drilling tool comprises a nonmoving or
rigid or largely nonmoving or rigid outer contour.
[0013] The term "ground drilling device" encompasses in the sense
of the invention any device which moves in particular a rod
consisting of rod sections in an existing or yet to be created
passage in the ground, in order to create or expand a borehole,
especially a horizontal drilling, or to lay pipelines or other long
bodies in the ground. A ground drilling device may comprise a
driving device which pushes and/or pulls a ground drilling rod. In
addition or alternatively, it may be provided that the driving
device drives the drilling rod in rotation.
[0014] The term "horizontal drilling" in the sense of the present
specification encompasses in particular any kind of existing or yet
to be created passages, preferably horizontal, in a body,
especially ground passages including earth boreholes, rock
boreholes, or earth conduits, as well as underground or aboveground
pipelines and water canals which can be produced or pulled in by
using a corresponding ground drilling device.
[0015] The terms "connection plug" and "connection socket"
encompass in the sense of the specification a configuration as one
element of a pair of mechanical coupling elements, of which the one
("connection plug") can be introduced at least partly into the
other ("connection socket") in order to form the connection.
[0016] The term "nonround segment" encompasses in the sense of the
specification a line segment along a cross section with which three
different points along the cross section are joined together,
wherein three points in particular cannot be situated along a
straight line or a circle segment. The nonround segment may in
particular be arc-shaped, including a configuration as an
arbitrarily curved line outside of a circular arc segment. The
nonround segment may be a curved line whose points have a different
distance from any given point in space, especially a center point.
The nonround segment may be described in partial regions by means
of formulas of the kind
x(a)=[R.sub.m-ecos(3.alpha.)]cos(.alpha.)-3esin(3.alpha.)sin(.alpha.)
y(a)=[R.sub.m-ecos(3.alpha.)]sin(.alpha.)+3esin(3.alpha.)sin(.alpha.)
[0017] The nonround segments comprise lines, edges or sides which
complement each other so as to form a closed polygonal line as a
cross section. In particular, a nonround cross section can be
formed which deviates periodically from a circle.
[0018] The term "constant" encompasses in the sense of the
specification a quality of the cross section such that the cross
section basically has no abrupt changes, i.e., the change in the
function values describing the cross section can be limited
arbitrarily by confining them to sufficiently small changes in the
argument, such as the polar angle. The term "constant" refers to a
macroscopic consideration, in which slight inconstancies might be
present.
[0019] According to the invention, it has been found that a form
fitting connection can be formed which may have mechanical
benefits, for example, a small form factor. A connection can be
created by which the highest torque in regard to the particular
diameter can be transmitted. The connection can basically be
designed with little or no notch effect. It is possible for the two
rod sections being joined to have two-dimensional contact with each
other, so that significantly less surface pressure may occur.
[0020] It has been found according to the invention that a cross
section having nonround segments for the connection plug and
connection socket may result in a greater torque transmitting
capacity, without enlarging the diameter of the rod section or the
participating connection plug and/or connection socket. In
particular, nonround segments can be used which together comprise
one or more segments obeying the same formula. In particular, the
cross section resulting from the nonround segments can be a
so-called polygon profile. According to the invention, it has been
found that a polygon profile may also have deviations, yet
nonetheless accomplish the effect according to the invention of
reducing the surface pressure, so that very slight deviations from
a polygon profile are possible. Deviations may be formed by
circular segments and/or straight segments. The nonround segments
may be respectively optimized in terms of a two-dimensional
contacting of connection plug and connection socket.
[0021] In one preferred embodiment, various nonround segments are
formed, so that in particular in the case of the connection socket
partial regions or segments can be formed which may be different
from each other and/or different from the contour of the connection
plug. In this way, the connection plug may be easily introduced
into the connection socket and a line contact between connection
plug and connection socket is avoided, which would entail a high
surface pressure. In particular, the connection socket may comprise
not only a pure "enlargement" of the outer contour of the
connection plug, but also in particular not be axially symmetrical
and/or rotationally symmetrical to the center point. In particular,
two mutually different nonround segments may be provided as the
cross section of the connection socket and/or the connection
plug.
[0022] In one preferred embodiment, two mutually different segments
may alternate along the circumference, so that segments are formed
which obey a given or predetermined function or formula, and which
are separated by other segments which obey a different
predetermined function or formula. Besides the providing of two
segments, it is also possible to provide further segments. The
providing of further segments is not ruled out, since according to
the embodiment at least one further segment is formed, not
represented by means of the (first) function, between two segments
which can be represented by means of the (first) function. The
segment which cannot be represented by means of the first function
may be directly or indirectly adjacent to one of the two other
segments. The segment which cannot be represented by means of the
first function may consist of circular segments or straight
segments.
[0023] In one preferred embodiment, in order to enlarge the
two-dimensional contact area, it is provided that the nonround
segments extend for a length of 20 mm to 120 mm, especially 30 mm
to 110 mm, especially preferably 60 mm to 100 mm, in the
longitudinal extension of the rod section.
[0024] In one preferred embodiment, an insertion segment is formed
at the entrance side to the nonround segments, being configured at
the end in particular on the connection plug or on the connection
socket. The insertion segment may at first have the respective
other element of the pair of the plug connection pass through it,
in order to arrive in the region with the nonround segments. In
this way, it is possible to achieve an easier introducing of the
connection plug into the connection socket. In the insertion
segment a relative rotational movement is possible between the
connection socket and the connection plug.
[0025] In one preferred embodiment, inside the rod section there is
present a plug connection for an electrical connection configured
coaxially to the connection socket or connection plug. The
configuration of the plug connection according to the invention
makes it possible to close the electrical plug connection under
constraint when forming the mechanical connection. The electrical
connection can also be closed with no movement other than that to
form the plug connection.
[0026] The invention also creates a driving element for driving a
ground drilling rod into the ground. The driving element is
configured to engage with a rod section. The driving element
engaging with the rod section is configured (a) as a connection
plug, having on the outside a cross section with nonround segments
or (b) as a connection socket, having on the inside a cross section
with nonround segments, while the cross section is constant.
[0027] In this way, a driving element of a driving device can be
used, which is designed for the special geometry of the rod
sections, so that a high torque can be transmitted in regard to the
diameter. A two-dimensional contacting of the driving element with
the rod section can be achieved and thus a significantly reduced
surface pressure.
[0028] The term "driving element" in the sense of the specification
encompasses an element of a driving device which provides for the
advancement of the ground drilling rod in the soil, whereby the
driving may be by pulling or by pushing, and the driving device in
addition may be designed to drive the ground drilling rod in
rotation. The driving element may be an element arranged on a
carriage. The carriage may be moved back and forth in or on a
frame, especially in parallel with the direction of the earth
borehole being made.
[0029] In one preferred embodiment, various nonround segments are
present. In particular, nonround segments which can be described by
means of the same function may be provided between segments which
can be described by means of another function. In this way, it is
possible to configure the connection socket in particular not just
as a pure "enlargement" of the outer contour of the connection
plug, but also in particular one that is configured not axially
symmetrical and/or rotationally symmetrical to the center point. In
particular, two mutually different nonround segments of the cross
section of the connection socket and/or the connection plug can be
provided.
[0030] In one preferred embodiment, the mutually different nonround
segments alternate along the circumference, so that an easily
constructed and easily manipulated cross section can be formed.
[0031] In one preferred embodiment, the nonround segments extend
for a length of 20 mm to 120 mm in the longitudinal extension of
the driving element.
[0032] In one preferred embodiment, an insertion segment is formed
at the entrance to the nonround segments in order to make it easier
to connect the driving element and the rod section. The driving
element can be moved relatively to the rod section or the rod
section relatively to the driving element for a certain region in
the insertion segment.
[0033] In one preferred embodiment, a plug connection for an
electrical connection to a rod section is present on the inside of
the driving element. In this way, an electrical connection of the
drill string can be accomplished by means of the driving element.
An electrical connection need not be laid outside of the rod
sections in order to provide a connection.
[0034] In one preferred embodiment, the plug connection is oriented
coaxially to the connection socket or to the connection plug, so
that a simple configuration can be achieved. A plug connection
oriented coaxially to the connection socket or the connection plug
may be rotation-invariant, especially when the connection socket
and connection plug are formed substantially centered in regard to
the cross section of the rod section or driving element. The design
of the connection socket/connection plug with a plug connection is
simplified. Furthermore, the plug connection can be formed on the
element provided for the mechanical connection.
[0035] The invention also creates a rod section system, which
comprises two or more rod sections of the above described
configuration.
[0036] In one preferred embodiment, the connection socket has a
form different from the connection plug. In particular, the
connection socket may be configured not only as a pure
"enlargement" of the outer contour of the connection plug, but also
in particular not axially symmetrical and/or not rotationally
symmetrical to the center point. For example, partial regions of
the cross section may serve as nonround segments for a clockwise
rotation as a bearing surface for corresponding bearing surfaces of
the connection plug and partial regions may serve as nonround
segments for a counterclockwise rotation as a bearing surface for
corresponding bearing surfaces of the connection plug.
[0037] Moreover, the invention relates to a ground drilling device
which comprises a driving element of the above described
configuration.
[0038] The preceding remarks, as well as the following description
of an exemplary embodiment, do not constitute any renouncing of
particular embodiments or features.
BRIEF DESCRIPTION OF THE DRAWINGS
[0039] The invention shall be explained more closely below with the
aid of an exemplary embodiment represented in the drawings.
[0040] The drawings show:
[0041] FIG. 1, an isometric view of a connection plug;
[0042] FIG. 2, a side view of the connection plug of FIG. 1;
[0043] FIG. 3, a view of the connection plug of FIG. 1 from the
front;
[0044] FIG. 4, an isometric view of a connection socket;
[0045] FIG. 5, a view of the connection socket of FIG. 4 from the
front, and
[0046] FIG. 6, a cross section transverse to the longitudinal
direction in the region of a connection plug inserted into a
connection socket.
DETAILED DESCRIPTION
[0047] FIG. 1 shows schematically in an isometric view a connection
plug 1, as may be provided at the end of a rod section or a driving
element. The end of the rod section or the driving element is
configured to form a plug connection. The connection plug 1 is part
of a pair which is formed in addition by a connection socket 2, as
is described more closely below. From the depicted first end of the
rod section or driving element there extends a center line 3 to a
second end (not shown) of the rod section or driving element. The
connection plug 1 comprises nonround segments 4 on its outside
along a cross section 5. The nonround segments 4 extend in the
longitudinal direction along the center line 3 for a region of 85
mm. There is formed a cross section 5 situated perpendicular to the
center line 3 and comprising substantially three nonround segments
4.
[0048] FIG. 2 shows schematically the connection plug 1 from the
side, wherein insertion segments 6 are formed on the connection
plug 1, being situated adjacent to the end of the rod section or
the driving element, in order to allow an easier connection to a
connection socket 2. Depressions are formed, extending in the
longitudinal direction (along the center line 3), being provided
for each nonround segment 4. The depressions of the insertion
segment 6 can interact as an insertion aid with a correspondingly
shaped insertion segment 6 on the connection socket 2 in order to
allow an orienting between connection plug 1 and connection socket
2.
[0049] From FIG. 3 it is seen that the rod section or the driving
element also comprises an electrical contact, which is present in
the form of an (electrical) connection plug 7, formed coaxially to
the (mechanical) connection plug 1.
[0050] FIG. 4 shows in an isometric representation a connection
socket 2, which may be present at one end of a rod section or a
driving element. The connection socket 2 comprises an insertion
segment 6, which extends across a longitudinally axial region of 20
mm.
[0051] FIG. 5 shows a front view of the connection socket 2.
Nonround segments 8 are provided to form an inside cross section 9
of the connection socket 2. The connection socket 2 comprises
coaxially an electrical connection socket 11 for an electrical
connection.
[0052] FIG. 6 shows a cross sectional representation which is
produced by introducing the connection plug 1 into the connection
socket 2. The sectioning is done substantially perpendicular to the
center line 3. FIG. 6 shows that the connection socket 2 in the
exemplary embodiment shown is not only a mere enlargement of the
outer contour of the connection plug 1, but also contains other
nonround segments 10 which the connection plug 1 does not contain.
Whereas for the connection plug 1 there are substantially provided
three nonround segments 4, the connection socket 2 contains two
times three nonround segments 8, 10, of which three correspond to
the three segments of the connection plug 1, but these are not
formed across the entire region, as in the connection plug 1. The
three nonround segments 8 corresponding to the nonround segments 4
of the connection plug 1 are separated by three of the nonround
segments 10 different from the nonround segments 4. This is shown
schematically in FIG. 6 in that the nonround segments 8 which
resemble each other in regard to the connection plug 1 and
connection socket 2 are provided with a dashed region, and the
regions in which the nonround segments 10 are not similar are
marked by a dashed and dotted region.
* * * * *