US3707196A

US3707196A - Sediment sample retriever

Info

Publication number: US3707196A
Application number: US162107A
Authority: US
Inventors: William P Verville
Original assignee: US Department of Army
Current assignee: US Department of Army
Priority date: 1971-07-13
Filing date: 1971-07-13
Publication date: 1972-12-26
Anticipated expiration: 1989-12-26

Abstract

A subaqueous sediment sample retriever head is affixed to the lower end of a continuous casing, which is positioned about a drill rod string and lowered onto a sampler tube, contiguous with the drill rod string. The retriever head houses in oppositely disposed cavities to a central bore, a pair of spools which store and actuate a flexible sealing slide respectively, and two pairs of spring actuated locking lugs which actuate simultaneously with the slide when the retriever head reaches the sampler tube bottom. A sleeve like follower device guides the retriever head onto the sampler tube and retains the sealing mechanism in an open position during mounting. The retriever head is advanced over the sampler by its own weight in conjunction with hydraulic jetting action.

Description

United States Patent 1151 3,707,196 Verville 51 Dec. 26, 1972 [54] SEDIMENT SAMPLE RETRIEVER Primary Examiner-James A. Leppink [72] Inventor. William P. Vervllle, Concord, N.I-l. Assistant Examiner Richard E Favreau [73] Assignee: The United States of America as Attorney-Chag'leS K, Wright, Jr. et a].

represented by the Secretary of the Army [57] ABSTRACT [22] Filed: July 13, 1971 A subaqueous sediment sample retriever head is affixed to the lower end of a continuous casing, which is [21] Appl' l62107 positioned about a drill rod string and lowered onto a sampler tube, contiguous with the drill rod string. The 175/2 0, 175/243 retriever head houses in oppositely disposed cavities [51] Int. Cl ..E2lb 7/12, E2) 25/00 to a central bore, a, pair of spools which store and 3c. Field of Search tuate a flexible sealing slide respectively, and two pairs 242 of spring actuated locking lugs which actuate simultaneously with the slide when the retriever head [56] References Cited reaches the sampler tube bottom. A sleeve like follower device guides the retriever head onto the sam- UNITED STATES PATENTS pler tube and retains the sealing mechanism in an 706,396 8/1902 Ebrenfeld ..17s/241 open position during mounting. The retriever head is 1,896,106 2/1933 Simmons.... ..175/243 X advanced over the sampler by its own weight in con- 2,915,284 12/1959 Ortloff ..175/233 X junction with hydraulic jetting action. 3,301,336 1/1967 Blount ..l75/5 3,409,094 11/1968 Kretschmer et al. ..175/242 10 Claims, 10 Drawing Figures '1 i\ 0 7 A I 1* B r PATENTED B I912 3 707. 19s

SHEET 1 0F 3 INVENTOR. WILL/AM P. VE'RV/LLE ATTORNEY SEDIMENT SAMPLE RETRIEVER The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment to me of any royalty thereon.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a subaqueous sediment sample retriever assembly, more particularly to a retriever head which is propelled by hydraulic jetting action and employs a flexible sealing slide which is self-actuating when the retriever head reaches the bottom of the embedded sample tube.

It is well known in the art that laboratory tests to determine the engineering characteristics of soil samples require that such samples approximate as nearly as possible, their natural state. Obtaining undisturbed samples of very soft, unconsolidated sediments, or saturated, cohesionless soils, or loose, compressible materials such as industrial waste products is a very real and serious problem. For a soil sample to be suitable for laboratory testing, there must be no disturbance of natural soil structure, no change in the water content or void ratio, and no change in the constituency or chemical composition.

bottom of said sampler tube. This is accomplished by housing a pair of oppositely disposed spool assemblies in the retriever head. A first spool stores a flexible slide which is retained in an open position by the outer sampler tube wall as said retriever head advances downward, and a second actuating spool draws the slide across the sampler tube bore as soon as the slide is advanced below the bottom of said sampler tube. Two pairs of oppositely disposed locking lugs, housed directly below the flexible slide, are actuated simultaneously with said slide providing support therefor.

Accordingly, it is an object of this invention to provide a self-actuating sediment sample retriever head which will sever the bottom of the sample from its en- It is a further object of this invention to provide a sediment sample retriever assembly which utilizes Disturbance of the soil structure may occur either during or after the actual sampling operation. Experience has shown that the use of thin wall tube samplers reduces the disturbance of the soil structure during the insertion stage to a very narrow zone on the outer surface of the sample. Maximum possibility for disturbance occurs when the sample is detached from the subsoil and during the subsequent withdrawal of the sampler tube from the bore hole. In addition to the force of gravity, suction on the sides and bottom of the sampler tube during withdrawal serves to further distort samples from their natural state.

2. Description of the Prior Art Various attempts have been made to obtain subaqueous soil samples in their undisturbed state. One of the early devices consisted of flexible metal fringes mounted on a ring which fit into the interior of a core barrel near the cutting shoe. These flexible metal fingers allowed the core sample to enter but were biased so that the sample was prevented from movement out of the barrel. The primary disadvantage of this type of device was that it restricted the core barrel entrance during corer penetration and it seriously disturbed and remodeled the core sample as the sample entered the barrel.

Another sample retriever of more recent design is described in a patent issued to T. R. Kretschmer et al., U.S. Pat. No. 3,409,094. This sample retriever is representative ofv those designs wherein the closure device is actuated upon withdrawal of the core retainer. This type of sample closure is not reliable, particularly in silt-like soils, in that proper sealing is dependent upon sufficient downward sediment forces to actuate the oppositely disposed pair of holding elements.

SUMMARY OF THE INVENTION The invention solves the aforementioned problems by providing a retriever head assembly which will automatically seal the sampler tube as soon as it reaches the hydraulic jetting action as its advancing means.

Another object of the invention is to develop a retriever assembly which can easily accommodate other drilling means so that this retriever apparatus mayv be used to sample various silt-like to course sediments.

These and 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. 1 is a side sectional view of the retriever head showing one pair of locking lugs;

FIG. 2 is an isolated, perspective view of the follower, showing the fluted waterways and locking lug recesses;

FIG. 3 is a partial sectional, perspective view of one locking lug assembly, showing the locking lug, cavity, and actuating spring;

FIG. 4 is a plan view of the upper section of the retriever head showing the removable crank used to wind up the stainless steel slide;

FIG. 5 is a perspective view isolating the spool assemblies and showing the slide in a half-open position;

FIG. 6 is the first in a series of sequential vertical sectional views showing a sampler tube and attached drill rod embedded in a subwater soil;

FIG. 7 shows the sample retriever head positioned about a drill rod with the follower in place holding the slide and locking lugs open;

FIG. 8 is a view of the'retriever head in a depressed position about the sampler tube showing the follower in its stopped position;

FIG. 9 shows the retriever head at the bottom of the sampler tube wherein the slide and locking lugs have been activated to seal off the sampler tube; and

FIG. 10 is the final sequential view showing the sampler tube assembly being withdrawn from the subwater soil.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings, more particularly to FIG. 1, a sediment sample retriever head 1 is shown in sealing position about the lower end of a sampler tube 2.

The retriever head is constructed of steel and consists of two main parts, an upper section 3 and a lower section 4.

The upper section 3 includes a threaded neck portion 5 to which is attached a flush joint casing 6 which extends upwardly to a control station, a smooth central bore 7, the diameter of which is approximately 5% inch larger than the outside diameter of the thin wall tube sampler to be used, a plurality of outwardly, downwardly, and angularly projecting waterways 8 emanating from the central bore 7 and extending to the outer edge of the retriever head, which together with the vertical, annular waterway 9 formed between the central bore 7 and the sampler tube 2, foster hydraulic jetting action generated from an above water head .of conventional design, and a pair of rectangular chambers 10 and 11 disposed on opposite sides of the central bore 7 which accommodate a pair of communicating spool assemblies 12 and 13.

The housing for a first spool assembly 12 is a dimensioned rectangular insert 14, the upper end of which is permanently affixed to a complementing rectangular chamber 10 by machine bolts 15. A storage spool 16 is adapted for rotary motion within said chamber by means of a pair of contiguous, oppositely disposed axle hubs 17 and 18 which fit into corresponding slots 19 and 20 located in end portions 21 and 22 of said rectangular insert, as shown in FIG. 4. t

The housing for a second spool assembly 13 is a similarly dimensioned rectangular insert 23 which is permanently affixed to a second complementary rectangular chamber 11 by machine bolts 24. A torsion spring activated spool 25 is similarly adapted for rotary motion within said chamber 11 by means of a pair of contiguous, oppositely disposed axel hubs 26 and 27 which fit into corresponding slots 28 and 29 located in end'portions of said rectangular insert. A fixed end torsion spring 30 is mounted within and activates said second spool 25 as shown by the cutaway portion of FIG. 4.

Directly communicating with both spool assemblies is a flexible stainless steel slide 31, the width of which is made to exceed the sampler tube 2 diameter as shown in FIG. 4. The flexible slide 31 is affixed to and stored on the storage spool 16 and two stainless steel wires 32 and 33 are attached to a positively tapered edge 34 of the slide and affixed to the spring activated spool 25.

When activated into sealing position, the flexible slide 31 is drawn through a longitudinal slot 35 in insert 14, across the central bore 9, and into mating engagement with a negatively tapered, longitudinal receiving slot 36 in oppositely disposed insert 23. Receiving slot 36 is provided with a pair of openings 37 and 3.8 through which stainless steel wires 32 and 33 pass.

An access hole 39 through the steel upper section leads, to axel hub 17 which is equipped with an Allen type recess 40. A hand crank 41 which is equipped with a male type Allen wrench 42 is inserted in the access hole to engage the axe] hub 17 of the storage spool. Said storage spool can thus be rotated to wind up the attached flexible stainless steel slide 31.

The lower section 4 of the retriever head is designed to fit the upper section 3 and is joined to it with machine bolts 43. A plurality of locking lugs 44 with means for actuating same are located around the central bore 7 in dimensioned cavities 45. The preferred embodiment shows two pairs of oppositely disposed locking lug assemblies located near the top of the lower section 4 with compression actuating springs 47 as shown in FIG. 1.

When actuated, the oppositely disposed pairs of locking lugs 44 move out of their respective cavities 45, into sealing engagement with one another, providing support to the flexible slide 31 which is actuated simultaneously. Although the preferred embodiment shows a plurality of locking lugs, it can readily be seen that a single locking lug member, extending across the central bore could also be utilized. I

The preferred embodiment of the instant invention utilizes hydraulic jetting action wherein a retriever head 1 is advanced over a sampler tube by means of its own weight in conjunction with the advance sediment erosion induced by the hydraulic jetting. There are instances, however, where the material to be sampled is too coarse grained or compact to be removed solely by jetting action. In such instances, the invention can be expanded upon to include a rotary drilling motion. By orienting the waterways 8 in an angular fashion and equipping the lower surface 49 of the retriever head lower section 4 with cutting blades, the invention can be made to hydraulically drill a hard surface. Tungsten carbide inserts, either sweated into or welded to the receiver head, are representative of suitable cutting blades.

As shown in FIG. 6, sampler tube 2 is contiguously affixed to the lower end of a drill rod string 48, of lesser diameter, which emanates from an overhead station. The annulus 50 formed between the outside diameter of the drill rod 48 and the inside diameter of the flush joint casing 6 accommodates water passage from a surface pumping station to provide the water pressure for the required jetting action.

Because of the diameter disparity between the sampler tube 2 and the drill rod string 48, a follower device 51 as shown in FIG. -2 is required. Follower 51 is adapted to guide the retriever head 2 over the drill rod string 48 onto the sampler tube 2 with means for retaining the locking lugs 44 and flexible slide 31 in an open position. More specifically, follower 51 is a cylindrical sleeve of steel construction, having an inside diameter which is approximately Vs inch larger than the outside diameter of the drill rod and an outside diameter which is the same as that of the sampler tube being used. Said follower includes a plurality of downwardly extending fluted waterways 52, a plurality of locking lug recesses 53 to retain said locking lugs in open position, and a beveled bottom 54 which engages and is retained by the tapered shoulder 55 of the sampler tube.

OPERATION OF SEDIMENT SAMPLE RETRIEVER A thin wall sampler tube 2 with a connecting drill rod string 48 is pressed into a subaqueous soil from an overhead station. Having inserted the sampler tube, a sample retriever head 1 with contiguous flush joint casing 6 and attached follower guide 51 is positioned about the drill rod string and lowered onto the shoulder 55 of the embedded sampler tube. At this point, hydraulic jetting action is instituted from the overhead station, whereupon the retriever head disengages from the follower 51 which remains atop the sampler tube, and the retriever head advances downwardly about said sampler tube propelled by its own weight and hydraulic jetting action as shown in FIG. 8. As the retriever head disengages from follower guide 51, the flexible slide 31 and locking lugs 44 simultaneously engage the outer diameter of the sampler tube, thus remaining in open position until the bottom of the sampler tube is reached. When retriever head 1 reaches the sampler tube bottom as shown in FIG. 9, the flexible slide and supporting locking lugs, no longer retained by the outside diameter of the sampler tube, are simultaneously spring actuated thereby sealing off the sampler tube bottom. At this point the hydraulic jetting action is stopped and the sampler tube is withdrawn with the inclosed and undisturbed sample.

lclaim:

1. A sediment sample retriever assemblycomprising in combination:

a. a drill rod string and attached sampler tube;

b. a casing and attached retriever head adapted to be positioned about said drill rod string and lowered onto said sampler tube;

c. drilling means for advancing said retriever head in a downward direction about said sampler tube; and

d. a flexible slide, with housing and actuating means, for sealing off a lower, open end of said sampler tube.

2. A sediment sampler retriever assembly according to claim 1 wherein said assembly further comprises a plurality of locking lugs, with actuating means, for supporting said flexible slide.

3. A sediment sample retriever assembly according to claim 2 wherein said assembly further comprises a follower device, adapted to guide said retriever head about said drill rod string and onto said sampler tube, wherein said follower device further includes means for retaining said locking lugs and flexible slide in open, nonactuated positions.

4. A sediment sample retriever assembly according to claim 3 wherein said sampler tube is of greater diameter than said drill rod string forming a shoulder on said sampler tube at the function of said drill rod string and said sampler tube providing a stop for said follower whereby further travel of said retriever head beyond said juncture disengages said locking lugs from to claim 1 wherein said drilling means compriseshydraulic jetting from an overhead pumping station which passes through a plurality of waterways located in said retriever head.

6. A sediment sample retriever head comprising in combination:

a. a central bore;

b. an upper section which houses a flexible slide, with actuating means, adapted to move between ;an open position and a closed, actuated position wherein said bore can be effectively sealed c. a lower section which houses a plurality otlockmg lugs, with actuating means, adapted to move between an open position and a closed, actuated position, thereby providing support for said flexible slide.

7. A sediment sample retriever head according to claim 6 wherein said upper section of said retriever head includes a plurality of waterways emanating from the central bore and extending to an outer periphery of said upper section.

8. A sediment sample retriever head according to claim 6 wherein said upper section includes a pair of spool assemblies housed in chambers oppositely disposed to the central bore, a first spool serving as a storage spool about which said flexible slide is stored, and a second actuating spool, communicating with said slide, which when actuated draws the slide across said bore, thereby sealing said bore.

9. A sediment sample retriever head according to claim 8 wherein said lower section includes two pairs of oppositely disposed, spring actuated locking lugs, housed in dimensioned cavities, oppositely disposed to said central bore.

10. A sediment sample retriever head according to claim 9 wherein said flexible slide and locking lugs are retained in an open position by a cylindrical sleeve like follower, the outside diameter of which is slightly less than that of said central bore.

Claims

1. A sediment sample retriever assembly comprising in combination: a. a drill rod string and attached sampler tube; b. a casing and attached retriever head adapted to be positioned about said drill rod string and lowered onto said sampler tube; c. drilling means for advancing said retriever head in a downward direction about said sampler tube; and d. a flexible slide, with housing and actuating means, for sealing off a lower, open end of said sampler tube.

4. A sediment sample retriever assembly according to claim 3 wherein said sampler tube is of greater diameter than said drill rod string forming a shoulder on said sampler tube at the function of said drill rod string and said sampler tube providing a stop for said follower whereby further travel of said retriever head beyond said juncture disengages said locking lugs from said follower, said locking lugs being maintained in an open, nonactuated condition by said sampler tube for the balance of travel of said retriever head on said sampler tube and being actuated to support said flexible slide upon completion of travel beyond said sampler tube.

5. A sediment sample retriever assembly according to claim 1 wherein said drilling means comprises hydraulic jetting from an overhead pumping station which passes through a plurality of waterways located in said retriever head.

6. A sediment sample retriever head comprising in combination: a. a central bore; b. an upper section which houses a flexible slide, with actuating means, adapted to move between an open position and a closed, actuated position wherein said bore can be effectively sealed; c. a lower section which houses a plurality of locking lugs, with actuating means, adapted to move between an open position and a closed, actuated position, thereby providing support for said flexible slide.