Information
-
Patent Grant
-
6390206
-
Patent Number
6,390,206
-
Date Filed
Tuesday, February 22, 200025 years ago
-
Date Issued
Tuesday, May 21, 200222 years ago
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Inventors
-
-
Examiners
Agents
-
CPC
-
US Classifications
Field of Search
US
- 175 5
- 175 6
- 175 7
- 175 8
- 175 10
- 175 58
- 175 50
- 175 60
-
International Classifications
-
Abstract
A hydrostatic working device for taking samples from the bottom of the sea. The working device has an outer tube (1), the cylinder tube (1), the cylinder tube with lead-through (5 and 7), and an inner tube (2), the sampling tube with a piston, whereby the space between the outer tube (1) and the inner tube (2), with the piston at the upper end, constitutes a low pressure chamber (29) filled by air under a moderate pressure, in order to keep the sampling tube (2) in an upper position until the valve opens for a working stroke. When the working device is used as a corer the sampling tube is at its lower end equipped with a catcher (4). When the tool is used as a CPT the lead-throughs (5 and 7) are replaced by (20 and 40) and the piston (3) with a piston (19), and the sampler tube (2) is replaced by a probe, and a choke valve (14) is replaced by a pressure compensated volumetric flow valve (39).
Description
BACKGROUND AND SUMMARY OF THE INVENTION
The invention is a hydrostatically driven working device, in particular a core sampler and a CPT sampler for investigation of sediments on the bottom of the sea, said working device comprising an outer tube (cylinder tube) and an inner tube (sampling tube), or a probe (CPT probe), having a piston fastened to the upper end of the tube/probe and a lead-through having a seal which surrounds the tube/probe at the lower end. This lead-through contains a valve for injecting and discharging air from the space between the outer and inner tube/probe, confined between the piston and the lower lead-through.
To the upper end of the outer tube is fastened a lead-through similar to the lower lead-through, without any air valve, said lead-through having no throughgoing bore for CPT, and to this lead-through is fastened an ear for attachment of a raising wire and with the possibility of attaching a wire for the piston. To the lower lead-through may be fastened a suction anchor for retaining to the bottom during the working stroke.
The working stroke starts when the raising wire becomes so slackened that the spring may open the valve which admits water through the choke valve to the piston, which is driven slowly downwardly, until the neck of the piston, having the same diameter as the sampling tube, passes the seals, and the working stroke starts when the water gets free access to the area between the outer and inner tube, the space between the piston and the lower lead-through being filled by air at an excess pressure which keeps the piston in its upper position until the valve opens.
For CPT the entire area above the piston will be a pressure area, and the stroke velocity will be adjusted to 2 cm/sec. by a pressure compensated flow rate regulation valve. Upon termination of the stroke the air cushion between the piston and the lower lead-through will expand and pull the tube back to its origin during pull-up. The liner will be confined between the catcher at the lower end and the clamping sleeve at the upper end. For expelling of the liner with the sample the clamping sleeve is removed and a piston is inserted in the neck of the piston, and a cover having supply of water is screwed into the neck, whereupon water having an excess pressure pushes out the liner and the sample.
By use of the same technique as for driving the sampling tubes into the sediment support legs may be shot down into the sediment in order to stabilize the sampler, said support legs being fastened to a device which can slide along the outer tube, the plate connecting the support legs being a brake against the raising forces during the shoot-down.
The invention may be combined as a twin, with one unit being a corer and another being CPT (Core Penetration Test), firmly connected to each other.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be closer explained in association to examples of embodiments shown on the accompanying drawings.
FIG. 1
shows a section through a first embodiment of a hydrostatic working device according to the invention.
FIG. 1
a
shows a variant of the embodiment of FIG.
1
.
FIG. 2
shows a twin-embodiment of FIG.
1
and
FIG. 1
a.
FIG. 3
shows
FIG. 1
a
and additional support legs.
FIG. 4
shows
FIG. 2
having support legs.
FIG. 5
shows a detail of the upper end of FIG.
1
.
FIG. 6
shows a detail of a device for controlling an inlet valve.
FIG. 7
shows a detail of the same device.
FIG. 8
shows a detail for expelling of liner with sample.
FIG. 9
shows a detail from the top of FIG.
1
.
FIG. 10
shows a detail of the lower end of FIG.
1
.
FIG. 10
b
shows a detail of the lower end of
FIG. 1
a.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION
FIG. 1
shows a section through a hydrostatic working device, in particular a corer, according to the present invention. The sampler consists of an outer tube (cylinder tube)
1
acting as a drive cylinder and an inner tube (sampling tube)
2
being a piston rod. At its upper end the piston rod has a piston
3
and at its lower end a catcher
4
. The cylinder tube
1
has at its upper end a lead-through
5
for the neck of the piston
3
and with a fastener for a raising device
6
. At the lower end of the cylinder
1
is positioned a lead-through
7
for the piston rod
2
and with a fastener for a suction anchor
8
. The cylinder
1
and the tube
2
may be composed of several lengths. The lead-through
5
and
7
may have a replaceable sleeve
41
with a gasket
42
.
FIG. 1
a
shows a variant of
FIG. 1
where the sampling tube has been replaced by a CPT probe
9
. The CPT probe may be composed of several lengths.
FIG. 2
shows a combination of FIG.
1
and
FIG. 1
a
constituting a permanent unit.
FIG. 3
shows
1
a
having support legs
10
. The support leg consists of a cylinder
34
, support leg
10
, piston
3
, lead-through
5
and
7
, valve
13
, spring
15
, rope
35
, rod having a support plate
36
and a frame
37
with a guide tube
38
. The support leg is shot down into the sediment when the support plate
36
reaches the bottom and the spring
15
can open the valve. Counterforce against the forcing down is constituted by flow resistance against the top and bottom plate of the frame
37
.
FIG. 4
shows a twin version of FIG.
3
.
FIG. 5
shows a detail of the upper end of
FIG. 1
, with a clamping sleeve
11
and a liner
12
.
FIG. 6
shows the upper end of
FIG. 1
, with an inlet valve
13
, a pressure compensated flow rate regulation valve
14
and a valve spring
15
.
FIG. 7
shows the upper end of
FIG. 1
, with an inlet valve
13
, a choke valve
16
and a wire for a piston
21
.
FIG. 8
shows a device for expelling of a liner with a sample, a piston
17
and an inlet seal
18
.
FIG. 9
shows a detail of the upper end of
FIG. 1
a
, with a piston
19
, which may have a sealed chamber for electronical storing of data, with a drain plug
43
and CPT probe
9
and cover
20
with sleeve
44
and plug
33
with seal
45
.
FIG. 10
shows a piston
22
, a suction anchor
8
, a flap valve
23
, an air regulation valve
24
and a plug
25
.
FIG. 10
b
shows
FIG. 10
in a CPT version.
FIG. 5
shows gaskets
25
,
26
,
27
and
28
which prevent water from getting into the cylinder chamber
29
and the slit
30
before the inlet valve
13
opens.
FIG. 6
shows the function of the valve device where the valve
13
is closed when the pull-up wire
31
is tightened because the rope
32
is fastened to the wire. The spring
15
opens the valve when the sampler reaches the bottom and the wire becomes slackened.
FIG. 7
shows a choke valve
16
which admits the water into the chamber above the piston
3
and the upper lead-through
5
, whereby the sampling tube is driven slowly down in order that the suction anchor
8
shall be given time for settling before the end of the neck of the piston passes the gaskets and permits free entry of water through the opening which equals the diameter of the piston rod. The area between the piston rod
2
and the cylinder
1
then becomes a pressure area, because the chamber
33
has air at a moderate pressure. The working stroke will occur rapidly until the air cushion is compressed and the stroke ceases, and the sampler can be lifted back to the vessel. During the stroke the piston
22
will be kept in place by the wire
21
which is fastened to the lifting device
6
, whereby a vacuum will be created below the piston, and an increased recovery will occur.
FIG. 8
shows a device for expelling the liner
12
with a sediment sample, whereby the clamping sleeve
11
is replaced by a piston
17
and an inlet seal
18
. After firstly having removed the catcher
4
, the seal
18
is subjected to water pressure, whereby the piston
17
will expel the liner with the sample.
FIG. 9
shows the CPR version, where the cover
20
is sealed, with inlet only through the inlet valve
13
and a pressure compensated volumetric valve
14
, in order to cause a constant velocity of 2 cm/sec.
FIG. 10
shows the suction anchor
8
, having a flap valve
23
for promoting the penetration into the sediment and simplifying the lifting when the working stroke is finished. The purpose of the suction anchor is to keep the sampler fastened to the bottom during the working stroke. The valve
24
is used to blow air into the chamber
33
in order to keep the sampler tube in place in the upper end until the working stroke starts and for pulling the tube back when the sampler is pulled up from the sediment. The plug
25
prevents ingress of water.
FIG. 10
b
shows the CPT lead-through.
Claims
- 1. A hydrostatic working device for use as at least one of a core sampler and a core penetration test sampler, for sampling of sediments at the bottom of the sea, wherein the working device comprises:an inner tube; an outer cylindrical tube having an upper lead-through and lower lead-through near ends of said inner tube, said lead-throughs having gaskets; a first piston movable in an annulus between the outer tube and the inner tube, said inner tube acting as a piston rod for the first piston; a catcher situated on a suction anchor which counteracts penetration forces; and a choke valve, wherein said first piston and said outer tube define sealed chambers below and above the first piston; wherein a flow velocity into the sealed chamber above the first piston can be regulated by said choke valve; and wherein the sealed chamber below the first piston constitutes a low pressure reservoir.
- 2. A hydrostatic working device according to claim 1, wherein said lead-throughs are cylindrical and have the same diameter.
- 3. A hydrostatic working device according to claim 1, further comprising a lifting device provided at the top of the upper lead-through.
- 4. A hydrostatic working device according to claim 1, wherein said suction anchor is provided at the lower lead-through, and includes a flap valve and an open-up cord fastened to a lifting wire.
- 5. A hydrostatic working device according to claim 1, further comprising a first inlet valve having an open-up spring and a cord, said first inlet valve being provided at the upper lead-through.
- 6. A hydrostatic working device according to claim 1, wherein said first piston has a neck with the same outer diameter as the inner tube, which defines said sealed chamber above the first piston during an initial part of a working stroke of the first piston.
- 7. A hydrostatic working device according to claim 1, wherein the device has a core penetration test arrangement, which includes a sealing upper lead-through and a pressure compensated volumetric flow valve to cause a constant velocity during the entire working stroke.
- 8. A hydrostatic working device according to claim 1, further comprising a liner kept in place by a clamping sleeve, which for expelling is replaced by a second piston and a second inlet seal.
- 9. A hydrostatic working device according to claim 1, wherein the lower lead-through has an air regulation valve and a plug for regulation of air pressure in the chamber.
- 10. A hydrostatic working device according to claim 1, wherein a third piston is situated at the lower end of a liner and a cord connects the third piston to a lifting device.
- 11. A unit comprising two hydrostatic working devices according to claim 1, one said working device comprises a core sampler and the other said working device comprises a core penetration test sampler combined into said unit.
Priority Claims (1)
Number |
Date |
Country |
Kind |
973858 |
Aug 1997 |
NO |
|
PCT Information
Filing Document |
Filing Date |
Country |
Kind |
PCT/NO98/00246 |
|
WO |
00 |
Publishing Document |
Publishing Date |
Country |
Kind |
WO99/10620 |
3/4/1999 |
WO |
A |
US Referenced Citations (10)