U.S. patent application number 11/696983 was filed with the patent office on 2007-10-18 for method and apparatus for operating an actuator.
This patent application is currently assigned to Tracto-Technik GmbH & Co. KG. Invention is credited to MANFRED SCHAUERTE.
Application Number | 20070240907 11/696983 |
Document ID | / |
Family ID | 38090907 |
Filed Date | 2007-10-18 |
United States Patent
Application |
20070240907 |
Kind Code |
A1 |
SCHAUERTE; MANFRED |
October 18, 2007 |
METHOD AND APPARATUS FOR OPERATING AN ACTUATOR
Abstract
A drilling or flushing medium is used in the operation of an
actuator for controlling an earth working device which uses the
drilling or flushing medium for its operation as well. The actuator
is acted upon by the medium , which can be retained in the actuator
through suitable operation of a valve assembly, while at the same
time can be supplied to the earth working device to execute a
desired function. The valve assembly is hereby actuated by a
separate switch.
Inventors: |
SCHAUERTE; MANFRED;
(Schmallenberg, DE) |
Correspondence
Address: |
Henry M. Feiereisen;Henry M. Feiereisen, LLC
Suite 4714
350 Fifth Avenue
New York
NY
10118
US
|
Assignee: |
Tracto-Technik GmbH & Co.
KG
Lennestadt
DE
|
Family ID: |
38090907 |
Appl. No.: |
11/696983 |
Filed: |
April 5, 2007 |
Current U.S.
Class: |
175/61 ;
175/73 |
Current CPC
Class: |
E21B 7/046 20130101;
E21B 23/04 20130101; E21B 21/10 20130101 |
Class at
Publication: |
175/061 ;
175/073 |
International
Class: |
E21B 7/04 20060101
E21B007/04 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 6, 2006 |
DE |
10 2006 016 613.2 |
Claims
1. A drilling or flushing medium for use in the operation of an
actuator for controlling an earth working device.
2. Apparatus, comprising: at least one actuator for controlling an
earth working device; and a valve assembly for operating the
actuator by means of a fluid selected from the group consisting of
drilling medium and flushing medium.
3. The apparatus of claim 2, wherein the valve assembly includes a
camshaft, and plural valves which are operated by the camshaft.
4. The apparatus of claim 3, wherein the valve assembly includes a
cylinder which is operated by the fluid and operatively connected
to the camshaft.
5. The apparatus of claim 2, wherein the actuator is configured as
lift pad.
6. The apparatus of claim 2, wherein the earth working device is
constructed for advancing along a predefined drilling route, and
further comprising a tool for correcting an advance of the earth
working device to compensate for a deviation from the drilling
course.
7. The apparatus of claim 3 , wherein the valves are spring-biased
valves.
8. The apparatus of claim 2, wherein the fluid is bentonite.
9. The apparatus of claim 2 for carrying out any one of the
operations selected from the group consisting of correcting a
deviation of a drill head in a pilot bore, when the earth working
machine is the drill head, correcting a deviation of an expansion
head, when the earth working machine is the expansion head and
lines are pulled in, opening and closing of valves or gates,
operation of borehole tools, disengagement or engagement of tools
in the ground, and moving out of a bore route for establishing
branch lines or for exploration.
10. A method for operating an actuator for controlling an earth
working device, comprising the steps of: subjecting the actuator to
a fluid selected from the group consisting of drilling medium and
flushing medium and used as the fluid for the earth working device;
and controlling an operation of a valve assembly such that the
drilling or flushing medium is retained in the actuator, while at
the same time is supplied to the earth working device for executing
a desired operation.
11. The method of claim 10, wherein the earth working device is a
drill head or expansion head.
12. The method of claim 10, wherein the controlling step includes
the step of actuating a separate switch for adjusting the operation
of the valve assembly.
13. The method of claim 10, wherein the valve assembly includes
plural spring-biased valves which return to their initial position
when a pressure of the drilling or flushing medium drops below a
spring force which acts on the valves.
Description
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application claims the priority of German Patent
Application, Serial No. 10 2006 016 613.2, filed Apr. 6, 2006,
pursuant to 35 U.S.C. 119(a)-(d), the content of which is
incorporated herein by reference in its entirety as if fully set
forth herein.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to a method for operating an
actuator, and apparatus for carrying out the method.
[0003] Nothing in the following discussion of the state of the art
is to be construed as an admission of prior art.
[0004] Earth boring and laying of pipelines in the ground involves
the use of tools or drill heads which can be controlled in various
ways. Examples include the use of asymmetric drill heads which can
be adjusted through turning at the hose, or a control of the head
by means of an asymmetric jet of drilling liquid issuing out of the
drill head. Control of the drill head may hereby serve for targeted
change in the drill course or also to only compensate for
variations in soil conditions. Conventional approaches, which use
actuators in the area of the drill head or other equipment elements
that are difficult to access in the ground, have all the basic
problem that any control of the actuators, which are also situated
inaccessibly in the ground, has to be carried out from ground
level, e.g. using mechanical systems, electrical auxiliary lines,
wireless communication, or a pressure medium source.
[0005] However, for a number of reasons, the various proposals are
endowed with drawbacks and shortcomings relating to the effect that
is hoped to be obtained but may not always be realized. For
example, purely mechanical solutions oftentimes are difficult to
operate in view of the conditions on the construction site and the
forces and frictions caused during drilling.
[0006] There is a special need for the precise control to realize a
compensation control for maintaining a straight drilling course in
the ground, when laying sewage lines at slight gradient is
involved, which are operated solely by the force of gravity. This
requires high precision, in particular for the installed depth,
because excessive deviations may result in deposits or clogging of
the sewage pipe during later operation. Difficulties arose when
installing lines into the ground because of the inability to
install them in a sufficiently straight manner along the intended
path. The vertical and horizontal rectilinearity always fluctuates
more or less. These fluctuations oftentimes exceed the admissible
tolerances, in particular when sewage lines are involved in very
flat terrain, so that the installation using current horizontal
drilling technique caused problems.
[0007] Known methods (open construction, auger equipments, etc.)
operate very slowly. Open construction may damage in some
circumstances high-quality surfaces which require repair after
installation. Respective methods are known from WO 02/057590 A2,
U.S. Pat. No. 6,668,946 B2, DE 196 05 983 C2, and DE 198 02 209
C2.
[0008] It would therefore be desirable and advantageous to provide
an improved method and apparatus for operating an actuator to
obviate prior art shortcomings.
SUMMARY OF THE INVENTION
[0009] According to one aspect of the present invention, a drilling
or flushing medium is used in the operation of an actuator for
controlling an earth working device.
[0010] According to another aspect of the present invention, an
apparatus includes at least one actuator for controlling an earth
working device, and a valve assembly for operating the actuator by
means of a drilling or flushing medium.
[0011] The present invention resolves prior art problems by
implementing an adjustment of the actuator (e.g. lift pad,
cylinder, etc.) by the potential energy (pressure energy) of the
provided drilling medium (e.g. bentonite). As a consequence, the
actuator can be operated inside a drilling tool or expansion tool
in the absence of any supply of separate control means (like e.g.
electric energy or hydraulic pressure). The use of respective feed
lines may also be omitted because the use of the drilling liquid,
which exists anyway, as control means eliminates the need for
additional supply lines and/or control lines which would have to be
conjointly routed e.g. from drill rod section to drill rod section
and respectively connected. Liquids that pose a hazard to the
environment, like e.g. hydraulic oil, are not necessary so that a
risk of soil contamination is avoided.
[0012] According to another feature of the present invention, the
valve assembly may include a camshaft, and plural valves which are
operated by the camshaft. Suitably, the valve assembly includes a
cylinder which is operated by the fluid and operatively connected
to the camshaft.
[0013] According to another feature of the present invention, the
actuator may be configured as lift pad.
[0014] According to another feature of the present invention, the
earth working device is constructed for advancing along a
predefined drilling route, wherein a tool can be provided for
correcting an advance of the earth working device to compensate for
a deviation from the drilling course. Thus, the tool is able to
correct any fluctuations of the drilling course in the absence of a
separate supply of electric current or other control means.
[0015] According to another feature of the present invention, the
valves may be spring-biased valves.
[0016] According to another feature of the present invention, the
apparatus is suitable for carrying out any one of the operations
selected from the group consisting of correcting a deviation of a
drill head in a pilot bore, when the earth working machine is the
drill head, correcting a deviation of an expansion head, when the
earth working machine is the expansion head and lines are pulled
in, opening and closing of valves or gates, operation of borehole
tools, disengagement or engagement of tools in the ground, and
moving out of a bore route for establishing branch lines or for
exploration.
[0017] According to another aspect of the present invention, a
method for operating an actuator for controlling an earth working
device includes the steps of subjecting the actuator to a drilling
or flushing medium used for the earth working device, and
controlling an operation of a valve assembly such that the drilling
or flushing medium is retained in the actuator, while at the same
time is supplied to the earth working device for executing a
desired operation.
[0018] According to another feature of the present invention, the
controlling step can be realized by actuating a separate switch for
adjusting the operation of the valve assembly.
[0019] According to another feature of the present invention, the
valve assembly may include plural spring-biased valves which return
to their initial position when a pressure of the drilling or
flushing medium drops below a spring force which acts on the
valves.
BRIEF DESCRIPTION OF THE DRAWING
[0020] Other features and advantages of the present invention will
be more readily apparent upon reading the following description of
currently preferred exemplified embodiments of the invention with
reference to the accompanying drawing, in which.
[0021] FIG. 1 shows a schematic illustration of a line and actuator
arrangement according to the present invention, with the actuator
assuming a moved-out position;
[0022] FIG. 2 shows a schematic illustration of the arrangement of
FIG. 1 in a control state, in which the actuator assumes a position
prior to moving out;
[0023] FIG. 3 shows a schematic illustration of the arrangement of
FIG. 1 in a control state in which the actuator assumes a position
prior to its return to an initial position; and
[0024] FIG. 4 shows a schematic illustration of a valve assembly
for controlling operation of the actuator.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0025] Throughout all the Figures, same or corresponding elements
are generally indicated by same reference numerals. These depicted
embodiments are to be understood as illustrative of the invention
and not as limiting in any way. It should also be understood that
the figures are not necessarily to scale and that the embodiments
are sometimes illustrated by graphic symbols, phantom lines,
diagrammatic representations and fragmentary views. In certain
instances, details which are not necessary for an understanding of
the present invention or which render other details difficult to
perceive may have been omitted.
[0026] Turning now to the drawing, and in particular to FIG. 1,
there is shown a schematic illustration of a line and actuator
arrangement according to the present invention for operating an
earth working device, e.g. a drill head or an expansion head. The
actuator, e.g. a lift pad, is positioned underneath a control gate
and is constructed to be able to move out by pressure applied by a
drilling liquid, which is used anyway for operation of the earth
working device, after the control gate with the lift pad is
transferred into the desired control direction by turning a drill
rod into the hold direction of a freewheel. After conclusion of the
control process, the control gate has to move back again (i.e. the
drilling liquid must be removed from the lift pad/actuator). A
further state involves drilling/expanding with the control
gate/lift pad having been moved out. All three control states are
realized through logic combination of three seat valves (check
valves) 3, 6, 8 which are acted upon by springs 2, 4, 9,
respectively, and locked alternatingly in the exemplified
embodiment by a camshaft 10 which is also operated by the drilling
liquid, as will now be described with reference to FIGS. 1-4.
[0027] FIG. 1 shows by way of example an expansion tool 5 which
includes in prolongation thereof a non-rotating control gate which
has been moved out via an actuator 1, e.g. a lift pad, by means of
a drilling liquid pressure generated by a drilling liquid pump 7.
The closed and locked valves 3 and 8 prevent escape of drilling
liquid from the actuator 1. Valve 6 opened by the drilling liquid
pressure allows a flow of drilling liquid to the expansion head 5.
This state of the valves 3, 6, 8 is shown in FIG. 4.
[0028] In FIG. 2, the actuator 1 should be lifted with drilling
liquid pressure. The drilling liquid pressure is initially reduced
to 0 bar so that all valves 3, 6, and 8 are returned to the closed
position by spring force applied by the spring 2, 4, 9. Turning in
this exemplified embodiment of the camshaft 10, shown in FIG. 4,
causes a locking of the valves 6 and 8. After the drilling liquid
pump 7 is switched on, pressure builds up in the actuator 1,
causing the actuator 1 to rise.
[0029] FIG. 3 illustrates the situation when the actuator 1, after
use, should be returned to its initial position again. At first,
the drilling liquid pressure is again set to 0 bar so that the
valves 3, 6, and 8 are returned to the initial position by spring
force applied by the spring 2, 4, 9. By continuing to turn the
camshaft 10 about 120.degree., the valve 3 is locked. Valve 8 is
opened by the ground pressure present at the control gate and thus
at the actuator 1, and the drilling liquid is able to escape the
actuator 1 into the soil. The locked valve 3 prevents a renewed
expansion of the actuator 1 when the drilling liquid pump 7 is
switched on so that the drilling liquid is able, without exception,
to flow via the unlocked valve 6 to the expansion head 5.
[0030] FIG. 4 depicts a section through the valve assembly and the
camshaft 10 used in this exemplary embodiment. The state described
in FIG. 1 is illustrated here. The indexed switching of the
camshaft 10 is implemented in this exemplary embodiment by a
single-action cylinder (not shown) which is also operated by the
drilling liquid. After decreasing the drilling liquid pressure to 0
bar, the drilling liquid pump 7 is suddenly switched on again. The
controls and the springs 2, 4, 9 of the valves 3, 6, and 8 as well
as an upstream faceplate cause actuation of the cylinder
chronologically before the valves so that the camshaft 10 is
indexed further.
[0031] While the invention has been illustrated and described in
connection with currently preferred embodiments shown and described
in detail, it is not intended to be limited to the details shown
since various modifications and structural changes may be made
without departing in any way from the spirit of the present
invention. The embodiments were chosen and described in order to
best explain the principles of the invention and practical
application to thereby enable a person skilled in the art to best
utilize the invention and various embodiments with various
modifications as are suited to the particular use contemplated.
[0032] What is claimed as new and desired to be protected by
Letters Patent is set forth in the appended claims and includes
equivalents of the elements recited therein:
* * * * *