US3383131A - Core sampler - Google Patents

Description

CORE SAMPLER Filed July 27, 1966 2 2 i 22 mun-2:1;

, FIG. 5.

INVENTOR. ANDRE M. ROSFELDER BY FIG. 4. Z

ATTORNEY.

United States Patent 0 3,383,131 CORE SAMPLER Andre M. Rosfelder, La Jolla, Calif., assignor, by mesne assignments, to the United States of America as represented by the Secretary of the Navy Filed July 27, 1966, Ser. No. 568,359 10 Claims. (Cl. 294-69) ABSTRACT OF THE DISCLOSURE The description discloses a tubular core sampler which utilizes a flexible tube at its lower end for closing such end when a core sample has been obtained. The closure is effected by twisting the flexible tube until the tube constricts any passage. The twisting action may be accomplished by a torsion spring which is connected at its ends to the respective ends of the tube. The spring is held in a biased condition with the flexible tube open until such time that closure is desired, whereupon the spring is released to twist the flexible tube for closure purposes.

The present invention relates to a closure valve and more particularly to a core retaining closure valve for use in combination with an underwater core sampler.

Underwater exploration has been under study for many years in an effort to acquire more scientific information about the undersea environment. One of the standard tools of underwear exploration is a core sampler, a device used to secure samples of the ocean bottom. While the use of core samplers is not new, many diflicult problems have arisen in regard to their use. Perhaps the most difficult problem has been the inability of the core sampler to retain the core once it has been secured, particularly in deep sea operations. The difficulties involved occur at various steps of the core sampling operation, for example: 1) after a core sample has been taken and removal of the core sampler started, a suction takes place at the bottom of the core sampler which tends to extract a part of the core; (2) if a small leak is present during ascent water tends to wash the core sample away; (3) once the core sampler is brought to the surface and before it is taken aboard ship, wide fluctuations in the pressure due to wave actions and handling operations often cause the core to suddenly collapse occasioning a total loss of the core just moments before complete retrieval. Accordingly, in most sampling operations it is necessary that a valve be employed to close the bottom of the core sampler so as to retain the soil sample therein.

Prior art core valves or retainers may be divided into two categories. The first type is the oldest and most common and can be classed as passive. Such retainers include finger springs which are devices that are comprised of thin strips of metal adapted to bend in one direction only so as to allow the core sample to enter the sampler tube while preventing its removal. A second such device is the flap valve. The flap valve is simply a small hinged plate allowed to open by the pressure of the entering core sample and then biased shut by a spring means when the pressure ceases. In addition, there are many passive core retainers which are mounted externally of the core sampler. The disadvantages of the passive devices are that they do not always close or that they injure or damage the sample because of protrusions adjacent the inside wall of the core sampler. Some of the external core retainers have proven to be too fragile for use.

The second category of core retainers, which seems to be more extensively used as it is more efficient and allows for less disturbance of the sample, can be classed as the dynamic type; this type relies on some additional source of energy for closure during the initial removal from the ground. Some of these devices work as follows: an expandable weight may close a turnable valve, a flap valve may be actuated by a wire leading to the surface vessel, or a rubber annular chamber may be expanded by pumping fluid from the surface vessel; but all these dynamic core retainers have the disadvantage of either being too complex and uneconomical or requiring some type of connection to the surface vessel.

The present invention overcomes the aforementioned disadvantages of prior art closure valves and features a novel and very inexpensive core sampling closure valve which imposes a minimum of disturbance on the soil sample and which may be adapted to effect automatic and tight closure of the corer upon its withdrawal from the soil. The present invention has been accomplished by providing a core sampler with a closure valve which comprises a flexible tube within the lower end of the core sampler which is capable of twisting to close the core sampler, a spring means adapted to twist the flexible tube to effect closure as the spring translates from a biased to an unbiased condition, and means for retaining and then releasing the spring means from a biased condition when the core sampler is to be closed.

An object of the present invention is to provide a core sampler with a closure valve which overcomes each of the aforementioned disadvantages of prior art closure valves.

Another object is to provide a very inexpensive core sampler with a closure valve which imposes minimum disturbance on the soil sample and is automatically actuated by upward withdrawal of the core sampler through the soil.

A further object is to provide a highly responsive and quick closing core sampler with a closure valve which can be constructed with thin walls so as not to obstruct the inner space of the core sampler nose and yet can be easily removed and replaced within the core sampler.

Other objects, advantages and novel features of the invention will become apparent from the following detailed description of the invention when considered with the accompanying drawing wherein:

FIG. 1 is a side view of a core sampler in the ocean bottom.

FIG. 2 is a top section view of the valve shown in open position taken along plane 22 of FIG. 1 or FIG. 4.

FIG. 3 is a top section view of the valve shown in closed position taken along plane 3-3 of FIG. 5.

FIG. 4 is a section side view taken along plane 4-4 of FIG. 2; and

FIG. 5 is a section side view taken along plane 55 of FIG. 3.

Referring now to the drawing wherein like reference numerals designate similar or corresponding parts throughout the several views, there is shown in FIG. 1 a core sampler 10 which has been driven by its own weight into the ocean bottom to secure a soil sample. The core sampler 10 comprises a tubular corer 12 which receives the core sample, and a weight means 13 to provide negative buoyancy. The tubular corer 12 comprises an outer tube 14, FIG. 4, within which is fitted a tubular liner 16 which may be constructed of a material such as plastic; the liner 16 with a core sample is removable from the outer tube 14 providing a convenient method for handling and storing the core sample until it is ready to be tested in the laboratory. The tubular corer 12 has at its bottom end a soil cutter 18 which is threaded at its upper extreme to the bottom of the outer tube 14 so as to allow for easy removal of the cutter in the event of breakage or in case the ocean bottom requires a different type of cutter. The closure valve is located at the lower end of the tubular corer 12 between the liner 16 and the cutter 18.

The closure valve comprises a flexible tube 20 which may be made of nylon and is situated generally concentric with the inner surface of the outer tube 14 in a generally loose condition as shown in FIGS. 2 and 4 when in an open position. As shown in FIG. 2, there are no protrusions which might damage a core sample and resistance to the sample is kept to a minimum. Thus, the core sample is received in substantially the same state as it is found on the ocean bottom. In addition, the lack of scratches or grooves formed in the core sample prevents the loss of a partial vacuum which is usually formed between the top end of the core sample and the top of the sampler tube. The vacuum provides an additional holding force retaining the core sample within the sampler tube. Another advantage is that the inside cutter dimension is not changed as the sample passes from the cutter 18 through the closure valve to the liner 16. Therefore, many of the disadvantages of the prior art are avoided.

The top end of flexible tube 20 may be connected to a support ring 22 while the bottom end may be connected to another support ring 24. Each support ring may be made in two annular sections so as to receive and retain an end of the flexible tube 20 therebetween thus providing for secure retention. The upper support ring 22 may be attached to the outer tube 14 by any suitable means such as by screws which may be easily removed to allow replacement. The other support ring 24 may be slidably and rotatably disposed within the core sampler so as to be able to move from a first position in which the flexible tube is open, as shown in FIGS. 2 and 4, to a second position in which the flexible tube is twisted closed as shown in FIGS. 3 and 5.

Connected to the flexible tube 20 and the outer tube 14 is a spring means 26 which may be in the form of a torsion spring. The spring means 26 may be substantially concentric with and located between outer tube 14 and the flexible tube 20 with each spring end adjacent and attached to a respective support ring. The movement of the spring means 26 as it translates from a biased to an unbiased condition twists the flexible tube 20 from an open to a closed position. As shown in FIGS. 2 and 4, the spring is in a biased position, the flexible tube in an open untwisted position; in FIGS. 3 and 5, the spring is shown in an unbiased position holding the flexible tube in a twisted closed position.

One of the main problems of the prior art devices is the inability to retain the core sample against the suction created when the core sampler is withdrawn from the ocean bottom. This disadvantage has been overcome in the present invention by having the core sampler automatically close as it begins to withdraw itself from the ocean bottom. The automatic closing is initiated by arelease means which may comprise a latch means 28 operatively connected to an arm 29. The latch means 28 may communicate with the support ring 24 through a slot 30 in the support ring and a slot 31 in outer tube 14 located opposite the slot 36 when the flexible tube 20 is in an open position. The latch means 28 may be a high pitch threaded screw with the slots 30' and 31 having corresponding high pitch threads.

The arm 29 is connected to the latch means 28 and is rotatable from a substantially upward position to a downward position. As shown in FIG. 4, the arm 29 is in an upward position when the flexible tube 20 is in an open position as the core sampler is driven into the ocean bottom. Upon the initiation of withdrawal of the core sampler, soil exterior the core sampler acts upon the arm 29 causing it to rotate to a downward position as shown in FIG. 5. The rotation of the arm 29 and the screw latch means 28 causes the latch means to disengage from the support ring 24. As the support ring 24 is no longer retained, the spring means 26 will be free to return to an unbiased position. Under the spring means influence the support ring 24 will rotate and slide to a new position as shown in FIG. 5. As the spring means translates to its unbiased position it twists the flexible tube into a closed position. Since the rotation of the arm 29 occurs immediately upon the core sampler being raised from the ocean bottom, there is little likelihood that much or any of the core sample will be lost. As shown in FIG. 5, once the valve closes, a tight substantially waterproof closure is formed. The tight closure prevents any leaks which may cause the core sample to break away and fall into the ocean. If the sampler should fail to close completely the biasing force of the spring means 26 will continue to exert a closing force on the flexible tube so that complete closure occurs when the obstruction or excess soil falls away.

The outer tube 14 is threadedly separated at 34 so as to enable quick and easy access to the closure valve in case of repair or replacement. The connection 34 also allows the lower part of the tubular corer 12 to be removed so as to allow the liner [16 with a core sample to be removed after it is back aboard ship.

Operation Operation of the core sampler is extremely simple and very reliabie. The core sampler 10 is either dropped over the side of a surface vessel or lowered into the ocean until it reaches the ocean bottom. The core sampler will penetrate the soil so as to cause a core sample to be received inside of the tubular corer 12. Once a core sample has been achieved it is desired that the sampler be closed to prevent destruction or damage to the sample. Closure occurs when the core sampler 10 is lifted upward out of the ocean bottom. The lifting causes the ocean sediment or soil exterior of the sampler to act downwardly on the arm 29 causing the arm to rotate from an upward position to a downward position. The rotation of the arm 29 causes the latch means 28 to disengage from the support ring 24.

Under the influence of the spring means 26 as it translates from a biased to an unbiased condition the support ring 24 will rotate and slide until the spring means 26 assumes the position as shown in FIG. 5. The rotating, sliding motion of the support ring 24 causes the connected flexible tube 20 to twist approximately so as to ciose the tubular corer 12 and retain the core sample. Tests have shown that the flexible tube 20 does not go through a quick circular motion cutting through the core sample but rather goes through a progressive strangulation of the core sample column, the flexible tube pushing continuously on the bottom of the core sample and taking the place of that which is displaced. Hence, there is a continuous spring bias to continually tighten around the bottom of the core sample and prevent loss of the sample.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

I claim:

1. A tubular core sampler comprising:

a tubular core receiving member;

a flexible tube adjacent the lower end of and substantially concentric with the inner surface of the tubular member and adapted to be twisted for closing said tubular member;

spring means, one end connected to the tubular member and the other end connected to the flexible tube, for twisting the flexible tube from an opened position to a closed position as the spring means translates from a biased to an unbiased condition; and

means connected to the tubular member for releasing the spring means from the biased condition to said unbiased condition,

whereby after a core sample is taken the release means is adapted to release the spring means which causes the flexible tube to twist and close the tubular member.

2. A core sampler as claimed in claim 1 including:

support rings connected to opposite ends of the flexible tube and to ends of the spring means, with one support ring being connected to the tubular member and the other support ring being slidably and rotatably disposed with said tubular member.

3. A core sampler as claimed in claim 2 wherein the spring release means comprises:

latch means disposed inside said tubular member for releasably retaining said other support ring with the spring in the biased condition;

an arm rotatably mounted to the exterior of said tubular member and capable of rotating from an upward position to a downward position with respect to the tubular member;

said arm being operatively connected to the latch means so that the support ring is retained when the air is in the upward position and the support ring is released when the arm is in the downward position, whereby upon withdrawal of the core sampler from the ocean bottom soil exterior the sampler will act on said arm to rotate it to said downward position to close said tubular member.

4. A core sampler as claimed in claim 3 including:

the other support ring having a slot therein;

the tubular member having a slot which is located opposite from the slot in the support ring; and

the latch means being disposed within said tubular member slot and engaging the support ring slot when the spring is in the biased condition.

5. A core sampler as claimed in claim 3 wherein the spring means is a torsion spring disposed between and substantially concentric with the inner surface of the tubular member and the exterior of the flexible tube.

6. A core sampler as claimed in claim 1 wherein each support ring comprises:

two sections adapted to retain an end of the flexible tube therebetween.

7. A core sampler as claimed in claim 1 wherein:

the spring release means includes means responsive to movement of soil adjacent the exterior of the core sampler upon withdrawal of said core sampler for releasing said spring means.

8. A core sampler as claimed in claim 1 wherein the spring means is a torsion spring disposed between and substantially concentric with the inner surface of the tubular member and the exterior of the flexible tube.

9. A core sampler as claimed in claim 1 wherein the flexible tube is a nylon cloth.

10. A core sampler comprising:

a tubular core receiving member;

a flexible tube disposed adjacent the lower end of and substantially concentric with the inner surface of the 6 tubular member and adapted to be twisted from an open to a closed position;

a pair of support rings connected to opposite ends of the flexible tube wherein one support ring is attached to the inner surface of the tubular member and the other support ring is slidably and rotatably disposed within said tubular member;

said other support ring having a slot;

said tubular member having a slot which is located opposite from the slot in the support ring;

a torsion spring disposed between and substantially concentric with the inner surface of the tubular member and the exterior of the flexible tube and connected at each end to a respective one of the support rings, said spring adapted to twist the flexible tube;

a latch means disposed within said tubular member slot and engaging the support ring slot with the spring in the biased condition;

an arm rotatably mounted to the exterior of said tubular member and capable of rotating from an upward position to a downward position with respect to the tubular member; and

said arm being operatively connected to the latch means so that the support ring is retained when the arm is in the upward position and the support ring is released when the arm is in the downward position,

whereby upon withdrawal of the core sampler from the ocean bottom soil exterior the sampler will act on said arm to rotate it to a downward position causing the spring to twist the flexible tube and thus close the said tubular member.

References Cited UNITED STATES PATENTS 562,628 6/1896 Lester 25174 X 1,582,936 5/1926 Shriver 175253 1,655,644 1/1928 Baker l75243 X 1,761,292 6/1930 Bone -240 1,960,973 5/1934 Knight 25174 X 2,746,225 5/1956 Cloud 2514 X 2,893,691 7/1959 Johnson 73-425 X 3,008,529 11/1961 Lynch et a1. 175243 3,188,070 6/1965 Lee 2514 X 3,302,464 2/1967 Langguth 175-58 X FOREIGN PATENTS 24,326 1899 Great Britain.

CHARLES E. OCONNELL, Primary Examiner.

I. A. CALVERT, Assistant Examiner.

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