US3008529A

US3008529A - Core sample retaining means

Info

Publication number: US3008529A
Application number: US787842A
Authority: US
Inventors: Eugene J Lynch; Frederick W Davenhall
Original assignee: Acker Drill Co Inc
Current assignee: Acker Drill Co Inc
Priority date: 1959-01-20
Filing date: 1959-01-20
Publication date: 1961-11-14
Anticipated expiration: 1978-11-14

Description

Nov. 14, 1961 E. J. LYNCH ET AL CORE SAMPLE RETAINING MEANS Filed Jan. 20, 1959 INVENTORS% E W. DAVENHALL EUGENfi' J. LYNG'H FIG.4 7

ATTORNEYS l 0 \v I J, 0 2 4 m 2 I Q. F 7 I v a I/(Inl F I. AM m/ F/ 1114442 7 w 3,008,529 CORE SAIVWLE RETAINING MEAN Eugene J. Lynch, Woodside, N.Y., and Frederick W.

Davenhall, Clarks Summit, Pa., assignors to Acker Drill Company, Inc Scranton, Pa., a corporation of Pennsylvania Filed Jan. 20, 1959, Ser. No. 787,842 8 Claims. (Cl. 175-243) This invention relates to soil sampling devices and more particularly, to a soil sampling device for collecting core samples in loose unconsolidated soils.

The main problem of collecting core samples in soils having a fluid or sandy consistency lies in retaining the core sample in conventional sampling tools.

Heretofore, it has been necessary to use check valves and other similar devices to retain loose or fluid core samples, and in some cases even these devices are unable to collect some types of soils. These devices raise the initial cost of the core sampling tools in which they are used. In addition, they create a maintenance problem as they tend to clog easily and are in need of constant attention.

It is, therefore, an object of this invention to provide a core sample retaining means for sampling tools, which is capable of retaining samples of heretofore uncollectable soils. 7 I

Another object of this invention is to provide a core sample retaining means which is low in initial cost.

Still another object of this invention is to provide a core sample retaining means which is readily replaceable and maintenance free.

Still another object of this invention is to provide a core sample retaining means readily adaptable to various soil sampling tools.

These and other objects of this invention will become apparent from the following specification and drawings. It is to be understood that the embodiment shown in the drawings and hereinafter described is for the purpose of example only and is not intended to limit the scope of the invention.

The invention consists, basically, of a flexible generally cylindrical tubular member mounted interiorly of a hollow core sampling tool. The tubular member is so mounted that it allows the core sample to enter the sampling tool when it is lowered into the soil but does not allow the core sample to escape from the tool when it is raised to recover the core sample.

In the drawings:

FIG. 1 is a cross-sectional view of the core sample retaining means in combination with a sampling tool in one phase of a sampling operation.

FIG. 2 is a detailed cross-sectional view of the core sample retaining means.

FIG. 3 is similar to FIG. 1 but relates to another phase of a core sampling operation; and

FIG. 4 is a view similar to FIG. 3 showing a fragmentary section of the upper portion of the flexible tubular member collapsed and folded across the tops of the spring fingers to form a barrier.

Referring in detail to the drawings, and more particularly to FIG. 1, a tubular core sampling tool is shown. The core sampler comprises an outer tubular shell which extends to an intermediate point 14 on the outer longitudinal dimension of the sampling tool 10 where it abuts with a tubular retaining collar 16.

Inside of the outer shell 12 and retaining collar 16 is a core sample retaining chamber generally indicated at 18 which is defined by a tubular inner shell 21 The inner shell 20 is provided with externally threaded end sections 22. The upper threaded section 22 cooperates with internal screw threads in the outer shell 12 while '2 the lower section 22 cooperates with an internally threaded section in the retaining collar 16. In this Way, the outer shell 12 and the retaining collar 16 are held in positive contact at the point 14. 7

Located interiorly of the retaining collar 16 and extending around the inner circumference thereof, is a mounting ledge 24. The mounting ledge 24 is adjacent the lower edge 26 of the inner shell 20 and axially spaced therefrom to provide a mount for the core sample retaining means to be hereinafter described. The mounting ledge 24 extends from the outside diameter of the inner shell 20 radially inward to a diameter defining a core sample inlet bore 28 in the lower end of the retaining collar 16.

' Referring to FIGS. 1 and 2, the core sample retaining device comprises a hollow cylindrical base member 30 having a relatively'thick lower portion 32 which is stepped to form a shelf 34. The shelf 34 extends radially inward to meet an upwardly'extending cylindrical section 36. The inner diameter of the lower section 32 and upper section 36 remains constant throughout the axial length of the base member 30 and is substantially equal to the diameter of core sample inlet bore 28 of the sampling tool 10.

A spring finger core retaining member comprising a constant diameter intermediate portion 38, base flange 40 and a plurality of upwardly extending spring fingers 42 circumferentially located about the intermediate portion 38 to form a truncated cylindrical section, is mounted on the base member 30. The constant diameter intermediate portion 38 of the spring finger core retaining member is in circumferential juxtaposition with the upwardly extending cylindrical section 36 of the base mem ber 30, while the base flange 40 of the spring finger core retaining member abuts the shelf 34 on the base member 30. The spring fingers 42 are of steel or other springy material and for the size of said sampler will flex about their lower ends but will not bend so as to be doubled back on themselves and project down into inlet bore 28.

A flexible generally tubular member 44 open at both ends is mounted with one end on the base member 30 exteriorly of the spring finger core retaining member by means of a cylindrical retaining collar 46- which cooperates with the intermediate portion 38 and base flange 40 of the spring finger core retainer and the shelf 34 and upper cylindrical portion of the base member 30 to secure the tubular member 44 and the spring finger core retainer to the base member 30. This combination comprises the core sample retaining device.

The upper end of the tubular member 44'comprises a multiplicity of flexible fingers 48 (FIG. 1) which act in combination with the rest of the tubular member 44- and the spring fingers 42 of the core retainer to provide a novel and positive core retaining action.

The core sample retaining device, as described, is mounted on the mounting ledge 24 in the retaining collar 16 of the sampling tool 10. The retaining collar 16 is then threaded onto the lower end of the inner shell member 20 to positively secure the core sample retaining device between the lower edge 26 of the inner shell 20' and the mounting ledge 24 on the retaining ring 16. The sampling tool 10 is now ready to take and retain a core sample of fluid or unconsolidated soils. 7

Referring to FIG. 1, the motion of the core sampling tool 10 is shown, by the arrow, to be in a downward direction. This direction of motion is used in forcing a core, of the soil to be sampled, up through the core inlet bore 28 in the retaining collar 16 of the sampling tool 10. As the sampling tool penetrates farther into the soil, the core sample, generally indicated at 50, is forced upwardly through the base member 30, spring fingers 42 3 and flexible tubular member 4-4 until the sample chamber 18 is filled.

If the core sample is fluid or of an unconsolidated nature, the spring fingers 4-2, above, would be insuflicient to prevent the core sample 50 from running back out through the inlet bore 28 and being completely lost when the motion of the sampling tool 19 is reversed to lift the tool and core sample 50 to the surface.

With the plastic tubular member 44 combined with the spring fingers 42, however, the results are altogether different,

Referring to FIG. 3, the arrow shows the direction of motion as having been reversed from that of FIG. 1. After the core sample St) has been forced into the chamber 18, the flexible bag 44 and the flexible fingers 48 thereon are stretched out to their fullest extent as shown in FIG. 1. Upon reversal of motion of the sampling tool 10, the core sample 50, due to its fluid or unconsolidated state, starts to flow out through the spring fingers 42 and inlet bore 28. The chamber 18, however, being longer than the tubular member 44 and the flexible fingers 48 thereon, contains core sample material 50 above the upper end of the tubular member 44.

The suction created by the escape of part of the core sample 50 causes the flexible fingers 4S and subsequently the tubular member 44 at its upper portion thereadjacent the fingers 48 to collapse and bunch and fold itself together and rest on and drape itself across the upper ends of the spring fingers 42 as shown in FIGURES 3 and 4. Thus, the core sample material 54 can no longer flow through the base member 30 of the core sample retaining means in that the tubular member 44 has collapsed and sealed off the opening therein. The core sample 5% located above the upper end of the tubular member 44 in the chamber 18 is thereby retained.

As can be seen from the above description and drawings our device satisfies a long felt need in the core sampling art for retaining samples of fluid and unconsolidated soils in their authentic, uncontaminated state. Heretofore, this was not possible with conventional sampling tools.

We claim:

1. A core sampling tool comprising, in combination, an inner shell defining a core retaining chamber, an outer shell surrounding and partially coextensive with said inner shell, said inner shell having an end section extending below the lower extremity of said outer shell, a hollow retaining collar, having an inlet bore therein communicating with said core retaining chamber, fixed to said end section of said inner shell and abutting said lower extremity of said outer shell, a mounting ledge interior of said retaining collar and spaced apart from the lower edge of said end section of said inner shell, and a core sample retaining device mounted between said mounting ledge and said lower edge of said inner shell, said core sample retaining device comprising ring means having spring fingers extending into said inner shell core retaining chamber in spaced relation therewith and a flexible relatively frail collapsible tubular member open at both ends and secured at one end in said ring means and extending between said inner shell and the spring fingers and beyond said fingers on into said core retaining chamber, said ring means with its spring fingers and the flexible relatively frail collapsible tubular member freely admitting core sample material into said core retaining chamber, said flexible relatively frail collapsible tubular member extending beyond said fingers and within said inner shell collapsing upon attempted exit of said core sample material that lies generally within the flexible relatively frail collapsible tubular member beyond said fingers and within said core retaining chamber and lying over said fingers across the opening formed thereby to form a transverse barrier and seal off said inlet bore and retain said core sample in said retaining chamber.

2. In combination with a core sampling tool havinga core retaining tubular shell device having an inlet bore and a core sample retaining chamber for collecting core samples of unconsolidated soils comprising, a truncated spring finger core retainer mounted in the bore of the sampling tool in spaced relation between the inlet bore sample and the core retaining chamber thereof, and a flexible relatively frail tubular member, open at both ends, aflixed at one of its ends to the base of said truncated core retainer and with the other end free to move in said core retaining chamber of said sampling tool beyond said truncated spring finger core retainer an amount so as to collapse and fold generally transversely over the ends of said fingers, whereupon when the weight of a collected core sample within the sample retaining chamber and within and above the relatively frail flexible tubular memher on withdrawing the sampling tool causes the free end of said tubular member to collapse and engage said spring finger core retainer to seal oil the bore of said sampling tool and prevent the escape of a core sample from said core retaining chamber.

3. The device as described in claim 2 wherein said free end of said tubular member comprises a plurality of flexible fingers. 1

4. In combination with a core sampling tool, having an inlet bore and a core retaining chamber, a core retaining means in the bore of said tool between the inlet bore and the core retaining chamber thereof, comprising a relatively frail flexible tubular member having one fixed end and one free end, both of said ends being open to allow passage of material through said flexible tubular member, a base member for said flexible tubular member mounted in the bore of said tool and having a bore therein communicating with the bore of said tubular shell, said fixed end of said flexible tubular member being fixed to said base member concentric with the bore therein, and said free end of said tubular member being free to move in the core retaining chamber of said core retaining tubular shell, whereupon when the weight of a collected core sample within the core retaining chamber and within and above the relatively frail flexible tubular member on withdrawing the sampling tool causes the free end of said flexible tubular member to collapse and in its collapsed condition to seal off the bore in said base member to prevent further escape of said core sample.

5. The device as described in claim 4 wherein said free end of said flexible tubular member comprises a plurarity of flexible fingers.

-6. A core sample retaining means comprising a hollow elongated base member having a bore therein and a flexible relatively frail and readily foldable open ended tubular member open at each end mounted at one end on said base member circumterentially of said bore therein whereby flow of a material through said bore in one direction is unimpeded and flow of material collected within said bore and beyond said flexible tubular memher through said bore in the opposite direction causes, when the core sample is withdrawn from taking a sample, said tubular member to collapse, fold upon itself and seal said bore to prevent further flow in said opposite direction.

7. A core sample retaining means comprising a hollow elongated base member having a bore therein, a truncated spring finger core retaining means mounted in said base member concentrically within said bore and having an aperture therethrough, a flexible double open ended relatively frail tubular member having one of its ends mounted concentrically within and attached to said base member and surrounding said truncated core retaining means, said flexible open ended tubular member having a free end extending beyond the outermost extremity of said truncated spring finger core retaining means a distance sufficient on collapsing of the tubular member that the tubular member crumples over said truncated spring fingers to close off the aperture therethrough, whereby material flowing through said bore and said truncated retaining means passes unimpeded through said tubular member and flow of material collected within and above the flexible relatively frail tubular member and above said spring finger core retaining means in the opposite direction collapses said free end of said tubular member into engagement with said truncated spring finger retaining means to seal 01f said bore and prevent further flow on Withdrawing the core sample retaining means from taking a core sample.

3. The device as described in claim 7 wherein said free end of said tubular member comprises a plurality of flexible fingers.

References Cited in the file of this patent UNITED STATES PATENTS Oliver Mar. 16, 1937 Johnson July 7, 1959 llildebrandt Mar. 8, 1960 FOREIGN PATENTS Sweden Apr. 21, 1938 France Apr. 3, 1955