US3647009A - Fluked core retainer - Google Patents

Abstract

An arrangement for retaining a soil sample in a sampling tube, especially but not exclusively from remote locations such as the floor of the ocean or other body of water. A series of pivoted fingers are circumferentially spaced about the end of the tube, each finger having a sharp leading edge and a fluked rear edge which catches in the soil surrounding the tube when the latter is withdrawn. This pivots the leading edge inwardly to close the lower end of the tube and supports the enclosed soil sample during tube withdrawal.

Description

United States Patent Drelicharz [54] F LUKED CORE RETAINER [72] Inventor: Joseph A. Drelicharz, 2317 Chico Court,

Oxnard, Calif. 93030 [22] Filed: Sept. 17,1970

211 Appl. No.: 72,907

[52] us. Cl ..175/242, 175/254 511 Int. Cl ..-.r;2 1 l gs [58] Field ofSearch ..175/20, 58,248, 249, 251, 175/253, 254, 242

[56] References Cited U NIT ED STATES PATENTS 1,889,277 11/1932 Draper ..175/254 2,161,582 6/1939 Mackenzie et 31.. ....l75/254 X 2,315,590 4/1943 Cantrell ....175/253 X 2,698,737 1/1955 Dean ....175/254 X Mar. 7, 1972 Du Berger l /254 3,095,050 6/1963 3,285,354 11/1966 Sanders et al 3,409,094 I l/ 1968 Kretschmer et al Primary Examiner-David H. Brown Attorney-Richard S. Sciascia, Q. Baxter Warner and Howard J. Murray [57] ABSTRACT An arrangement for retaining a soil sample in a sampling tube, especially but not exclusively from remote locations such as -the floor of the ocean or other body of water. A series of 5 Claims, 11 Drawing Figures PATENTEDMAR 7 m2 SHEET 1 [IF 3 I ONE FLUKE REMOVED SEPH A. DREL/CHARZ INVENTOR 6km, y AGENT 22 (0 I PATENTEDMAR 7 I972 SHEET 2 [IF 3 Fig.3

,ONE FLUKE REMOVED PAIENIEDHAR mm SHEET 3 [IF 3 Macaw FLUKED CORE RETAINER STATEMENT OF GOVERNMENT INTEREST BACKGROUND OF THE INVENTION Increasing interest in oceanography, and especially in the extraction of oil and minerals from beneath the surface of the sea, has led to the development of devices for obtaining samples of the soil at selected underwater locations where exploratory action is contemplated. Analysis of these samples yields useful information as to the composition and consistency of the sediment and hence aids in determining whether further exploratory efforts are indicated and if so the most efficient procedures to be employed.

However, many arrangements now being utilized for obtaining such soil samples are not completely satisfactory in that they are either so complex as to be unreliable or else that they possess a relatively poor area ratio (the ratio of the difference between the sectional core barrel area and the sectional core sample area to the sectional core sample area). A poor area ratio indicates a thick core barrel, causing excessive disturbance of the soil sample and introducing errors into the derived data. Devices which incorporate springs and levers fall in the above category, as well as those that are operated with wire actuators from some remote point such as a surface vessel.

SUMMARY OF THE INVENTION The present invention is directed to a core retainer of simple design which is capable of efficient operation in many different environments. The concept embodies a tubular body around the lower end of which a plurality of pivoted fingers are circumferentially disposed, these fingers respectively lying within recesses in the retainer body while the latter is being driven down into the soil. Hence the fingers offer no resistance to soil penetration and cause no disturbance of the sample. However, during pullup of the device, a'fluked rear edge of each finger catches in the soil exterior to the tube and forces the finger to pivot until that portion thereof within the retainer lies essentially horizontal and at right angles to the tubes longitudinal axis. This in effect blocks the open end of the tube and prevents any dislodgement of thesample during the remainder of the extraction'proeess. An exterior sleeve maintains the fingers in closed position after the tube leaves the soil and until the sample is removed.

STATEMENT OF THE OBJECTS OF THEINVENTION One object of the present invention, therefore, is to provide a core retainer which is simple in design and adaptable to many different types of environments.

A further object of the invention is to provide a core retainer which has a low area ratio and which operates to extract a soil sample with minimum disturbance thereto.

An additional object of the invention is to provide a core retainer having a plurality of pivoted fingers each of which is provided with a fluked rear edge adapted to catch into the soil when the retainer is withdrawn, thereby pivoting the fingers to closed or core-retaining position.

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

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a sectional view of a portion of a core retainer constructed in accordance with a preferred embodiment of the present invention, showing the device in open position to receive a core sample;

FIG. 2 is a full sectional view taken along the line 22 of FIG. 1;

FIG. 3 is a view of the core retainer of FIG. 1 illustrating the device in closed position;

FIG. 4 is a full sectional view taken along the line 44 of FIG. 3;

' FIGS. 5a, b, c and d illustrate the relative positions of certain parts of the core retainer during soil penetration and withdrawal;

FIG. 6 is a preferred design for one of the fingers of the embodiment of FIGS. 1 through 5; and

FIGS. 7a and b illustrate the manner in which a curved slot may be formed in the fingers of FIG. 5.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, there is shown in FIG. 1 a sectional view of the invention device in open position. It comprises a tubular body member 10 having an upper portion 12 to hold the soil-sample and a lower portion 14 constituting the core head, the latter being threadably attached to the upper body portion 12 at 16. In use, a core sample is retained within body portion 12 while theapparatus is brought back to a laboratory or other examination point.

To achieve this result, there is provided a plurality of fingers 18 spaced-apart in circumferential fashion around the body portion 14 near the lower end thereof, as illustrated in FIGS. 1 and 2. Each of the fingers 18 has a sharp leading edge 20 extending downwardly as viewed in FIG. I, and a fluked rear edge 22. The leading edge 20 of each finger 18 is sharply pointed while the fluked rear edge 22 is relatively wide in order to catch into the soil surrounding the tube upon retainer withdrawal. This acts to pivot the leading edge 20 of the finger inwardly to close the lower-end of the tubular body member 10, thereby supporting a retained core sample. To allow for this operation, each finger 18 is designed with a narrow intermediate portion 24 interconnecting its sharp leading edge 20 and its fluked rear edge 22. This narrow intermediate portion 24 is pivoted on a pin 26 inserted into the body portion 14 of the assembly, as best illustrated inFIG. 2 of the drawings. Consequently, during soil penetration, the fingers 18 have positions relative to the body member 14 as shown in FIGS. 1 and 2, with their leading edges 20 essentially flush with the inner surface 28 of the tube portion 14. The fluked rear edges 22 of the'fingers also lie close to the tube body, each suchedge abutting a cam surface 30 (FIG. 1) which limits movement of finger 18 and also enables such finger to resist the pressure developed thereon when theassembly is forced downwardly intothesoil.

Enclosing the core'retainer body portion 12 is a sleeve 32 slidablelongitudinally of the core retainer and having an outwardly flared lower end portion 34. The latter has a circumferential groove 36 cut thereinto adapted to receive the fluked rear edges 22 of the fingers l8 when the various portions of the assembly are in their relative positions shown in FIGS. 1 and 2, or, in other words, during the initial period of downward movement'of the core retainer. This will be subsequently described in conjunction with a discussion of FIG. 5a of the drawings. In such position of FIG. 1, the fingers 18 are held so that their sharp leadingedges 20 are essentially parallel to, and flush with, the inner surface 28 of the tubular body member 14, and with their fluked rear edges 22 resting against the cam surface 30.

OPERATION The operation of the invention device is illustrated in FIGS. 5a through 5d of the drawings. Initially, the entire assembly descends, the lower portion 14 penetrating the soil as shown in FIG. 5a. This is the Driving Mode No. 1. This action continues until the flanged end portion 34 of the sleeve 32 contacts the soil surface. At this point, a sliding action takes place between the sleeve 32 and the tubular body member 10, the latter continuing to move downwardly while the sleeve 32 is prevented from so doing by contact between the flared end 34 and the soil surface, as illustrated in FIG. 5b, or Driving Mode No. 2. The fluked edges 22 of the fingers 18 leave the groove 36, but the fingers are prevented from pivoting by pressure of the soil against the wide surface of the fluked edge 22, the soil movement relative to the fluked rear edges of the fingers 18 being represented by the arrow 38.

When the sampling device has reached its desired penetration of the soil so as to enclose a sample therewithin, the downward movement terminates and it is withdrawn. As soon as upward motion begins, as illustrated in FIG. 5c, Withdrawal Mode No. l, the fluked rear edges 22 of the fingers l8 catch into the soil, and the soil pressure depicted by arrow 40 causes such fingers to rotate about their respective pivots 26 to bring their sharp leading edges 20 upwardly and inwardly relative to the tubular portion 14. This action continues until the parts have assumed their relative portions of FIG. 4. As shown therein, the edges 20 of all the fingers l8 effectively close the lower tubular portion 14 of member 10 and prevent the soil sample entrapped in tube portion 12 from dropping out during the withdrawal operation.

When the upward movement of the core retainer has resulted in the fluked edges 22 of fingers 18 reaching the surface of the soil, the soil pressure represented by arrow 40 in FIG. 5c is no longer present. This would normally result in a reverse rotation of the fingers due to gravity acting on the retained soil sample, allowing the sample to drop out of the end of the retainer. However, when the fluked edges 22 reach the soil surface, they engage the lower surface of the flanged portion 34 of the sleeve 32 as shown in FIG. 5d, Withdrawal Mode No. 2. Further upward motion of tubular member 12 now draws sleeve 32 upwardly therewith, the engagement of the latter with the fluked edges 22 of fingers l8 preventing the latter from pivoting and maintaining the sharp leading edges 20 projecting radially inwardly to hold the core sample in place.

The sharp leading edges 20 of the fingers 18 may be configured to conform to the nature of the particular type of soil a sample of which is to be extracted. In FIG. 6 is shown one preferred design. However, their shape is chosen according to the nature of the sample, since, on the onset of the removal or extraction step, the sharp edge 20 of the finger cuts into the sample and retains it, hence this portion of the finger must be large enough to prevent loss of the sample. The area of the edges 20 (looking along the axis of the tubular member 10) taken together as a unit should be at a maximum (as in FIG. 4) for soil made up of noncohesive materials. For normal soils, only about one-half of this maximum area is required; for highly cohesive soils, as little as one-quarter the area is needed. The criterion is that the sample be effectively held in place by the particular set of fingers employed.

The sleeve 32 should be long and with a low center of gravity so as not to bind the tubular member 10. As above brought out, it functions as a keeper when the fingers 18 are out of contact with the soil both in the driving (FIG. 5a) and withdrawal (FIG. 5d) modes. In other words, the fluked edges 22 lie in the groove 36 during the former movement, while such edges abut the outer surface of the flared end 34 of the sleeve 32 during the latter phase.

Generally, the dimensions of the various parts are not critical, and the diameter of the head can be chosen to fit the particular environmental conditions encountered. For fingers having rather narrow cutting edges 20, assembly is accomplished by inserting them in a downward direction in slits 42 (one of which is visible in FIG. 1) in tube portion 14. They are then snugged-up" into the head and the pins 26 inserted (see FIG. 2). With wide cutting edges (as in FIG. 4) the fingers should be designed so that either the cutting edge or the fluked rear edge is removable. FIG. 6 illustrates the former, the cutting edge being slid down a dovetail to a fluke. An alternate procedure is to screw this part into place. FIG. 7 illustrates how a curved slot 44 may be utilized and within which the pin 26 rides when finger 18 moves from driving mode (FIG. 7a) to withdrawal mode (FIG. 7b).

The above process allows differently shaped fingers to be used with different diameter core retainers, adding to the flexibility of the invention.

Since both the tube portions 12 and 14 are of thin construction, the invention device has an extremely low area ratio. Furthermore, no mechanical actuators, levers, or springs are utilized. Hence, reliability is high with negligible possibility of malfunction, Also, no scarring or other disturbance of the sample occurs, since the internal flanges are recessed and hence do not exert any forces on such sample in the driving modes.

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.

Iclaim:

1. A core retainer for obtaining a soil sample from a relatively inaccessible location, said core retainer comprising:

a sampling tube within which the soil sample is to be retained, said tube having a plurality of openings spacedapart circumferentially near one end thereof; and

. a plurality of fingers equal in number to the number of openings and respectively pivotally receivable therein,

each of said plurality of fingers having a sharp leading edge lying within said sampling tube and a fluked rear edge lying outside said tube, said leading edge resting essentially flush with the inner wall of said tube when the latter is penetrating the soil a sample of which is to be obtained,

said fluked rear edge being designed to catch into the soil surrounding said tube when the latter is withdrawn from the soil to pivot the finger of which it is a part and orient the leading edge thereof to a position in which it projects radially inwardly and essentially normal to the longitudinal axis of the tube,

the combined pivoting action of said plurality of fingers being effective to close the end of said tube and retain the said soil sample therewithin.

2. A core retainer according to claim 1 further comprising:

a sleeve carried on said sampling tube and slidable therealong, said sleeve engaging the fluked rear edge of each of said fingers while the latter are above the surface of the soil to be sampled.

3. The combination of claim 2 in which said sleeve is formed with a flared end portion, such flared end portion having a circumferential groove cut therein into which the fluked rear edges of said fingers are receivable prior to the time such fingers penetrate the soil a sample of which is to be obtained.

4. The combination of claim 3 in which each finger of said plurality is pivoted in its respective opening on a pin supported by said tube.

5. The combination of claim 4 in which the flared end portion of said sleeve is designed to engage the fluked rear edge of each of said plurality of fingers when the latter leave the soil upon withdrawal of said tube, thereby maintaining the sharp leading edge of each finger projecting radially inwardly and preventing the enclosed soil sample from dropping out of said tube.

Claims (5)

1. A core retainer for obtaining a soil sample from a relatively inaccessible location, said core retainer comprising: a sampling tube within which the soil sample is to be retained, said tube having a plurality of openings spaced-apart circumferentially near one end thereof; and a plurality of fingers equal in number to the number of openings and respectively pivotally receivable therein, each of said plurality of fingers having a sharp leading edge lying within said sampling tube and a fluked rear edge lying outside said tube, said leading edge resting essentially flush with the inner wall of said tube when the latter is penetrating the soil a sample of which is to be obtained, said fluked rear edge being designed to catch into the soil surrounding said tube when the latter is withdrawn from the soil to pivot the finger of which it is a part and orient the leading edge thereof to a position in which it projects radially inwardly and essentially normal to the longitudinal axis of the tube, the combined pivoting action of said plurality of fingers being effective to close the end of said tube and retain the said soil sample therewithin.

2. A core retainer according to claim 1 further comprising: a sleeve carried on said sampling tube and slidable therealong, said sleeve engaging the fluked rear edge of each of said fingers while the latter are above the surface of the soil to be sampled.

3. The combination of claim 2 in which said sleeve is formed with a flared end portion, such flared end portion having a circumferential groove cut therein into which the fluked rear edges of said fingers are receivable prior to the time such fingers penetrate the soil a sample of which is to be obtained.

4. The combination of claim 3 in which each fingEr of said plurality is pivoted in its respective opening on a pin supported by said tube.

5. The combination of claim 4 in which the flared end portion of said sleeve is designed to engage the fluked rear edge of each of said plurality of fingers when the latter leave the soil upon withdrawal of said tube, thereby maintaining the sharp leading edge of each finger projecting radially inwardly and preventing the enclosed soil sample from dropping out of said tube.

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