US3047081A - Soil sampler - Google Patents

Description

July 31, 1962 J. N. PITCHER 3,047,081

SOIL SAMPLER i gf A T TOM/EMS July 31, 1962 Filed April J. N. PITCHER SOIL SAMPLER 2 Sheets-Sheet 2 INVENTOR.

JOHN N. PITCHER A TTOPNEVS United States This invention relates to a soil sampler, and has for one of its objects the provision of a thin wall or Shelby type soil sampler that is adapted to provide a correct sample of soil overa predetermined depth, and which may be of different degrees of firmness from relatively soft to relatively hard soil, and which may include rock.

Thin wall samplers are also known generally as Shelby or Shelby Type samplers, that include a Shelby tube in which the sample to be analyzed is contained.

The normal procedure has been to first drill a hole with any conventional drilling equipment that provides a reasonably clean hole.

After the hole is drilled to the desired level at which a sample is to be taken, a thin walled tube, provided with a sharpened lower edge, and open at its lower end is lowered into the hole so that said lower edge rests on the soil at said level. The tube is then forced downwardly, without impact or twisting, into the soil to ll the same.

The tubes that are used have usually been from .approximately two to five inches in diameter and say up to twenty diameters in length, according to the characteristics of the soil, the longer tubes being where the soil is cohesive and the shorter tubes and smaller diameter tubes, where the soil is relatively uncohesive.

After the tube is filled with soil, it is withdrawn from the hole, and is removed from the rod or pipe that has lowered it into the hole, a predetermined amount of enclosed material is removed from the ends of the tube, and then the ends are sealed with wax, or in any other suitable manner, and the tube is sent to the laboratory, where it is split to reveal the sample and for making an investigation thereof.

There are a number of objections to the conventional structures heretofore employed for taking soil samples. One of these is that no satisfactory Shelby type or thin wall soil sampler heretofore employed, insofar as I am aware, is capable of obtaining an accurate satisfactory sample where strata of rock or firm soil is encountered, since the tube cannot be forced through such formations. The tube in which the sample is enclosed shouldV not be twisted or driven by impact or manipulated in a manner that may disturb the sample, since the sample within the tube must accurately reflect the condition of the soil at the level from which it is taken, or it is of little, of any, value. y

Also, heretofore, the manner in which water is employed to assist in taking a sample has resulted in the sample being wetted to produce a false condition and one that is not a true reliection of actual conditions.

Heretofore, in many instances, the bottom of the hole may not be properly cleaned before the lower end or edgeV of the sampler tube is positioned at the lower end of the hole for taking a sample, and an undesirable quantity of loose material at the bottom end of the hole will enter the tube.

The present invention provides a structure that is adapted to overcome the aboveobjections, Aand others, to the use of the heretofore available soil samplers, and which invention is adapted for use with standard equipment.

Other objects and advantages will be .apparent from the drawings and description. f i

In the drawings,

FIG. 1 is a vertical sectional view taken through the soil sampler, with the sampler tube in a fully retracted position as would occur when the sampler tube is in enV gagement with har-d soil or rock that cannot be penetrated solely by pressure in the tube. A

FIG. 2 is a part sectional, part elevational view similar to that of FIG. 1, but showing the soil sampler tube in engagement with rm earth or soil that it is adapted to be moved into for taking a'sample. y

FIG. 3 is a vertical sectional view similar to that of FlG. 2, but showing the sampler tube fully extended and filled with a sample, as would occur in removing the tube from a hole.

FIG. 4 is a cross sectional view taken along line 4-4 of FIG. l.

FIG. 5 is an enlarged, fragmentary cross sectional view taken along line 5 5 of FIG. 6.

FIG. 6 is a cross sectional view taken along line 6 6 of FIG. 3, but indicating in dot-dash lines the ends of the flutes in the element thereabove.

In detail, referring first to FIG. 3, this view shows a thin wall, Shelby, soil sampler tube, generally designated l, as constituting the inner tube of the soil sampler, and` it is indicated in fully extended position with the soil 2 therein. This is also the normal position of the inner tube 1v with respect to the outer tube 3 with which the inner tube'is telescopically connected when the' soil sampler is empty and is first lowered into the pre-drilled hole 4 (FIG. 2) in the ground and before any pressure is exerted on tube 1.

The words soil sampler as used herein refer to the device that includes the outer tube 3 and the parts enclosed thereby, as well as the sampler tube V1. The sampler tube relates to the tube 1 including its head.

The soil sampler and parts-thereof will fbe described with the sampler in a vertically extending position for the purpose of deniteness in useV of the words uppen l0wer, and -words of like import. v

`The outer tube 3 of the soil sampler is provided with an'annular cutting bit 5 at its lower end Coaxial therewith, and through the central opening in which the innerv or sampler tube 1 is adapted to slidably project in close relation to the inner sides' of' the bit. The axially downwardly and radially outwardly directed sides of the bit" are respectively provided with cutting teeth 6, 7 and the radially inwardly facing sides are formed with verticallyv extending liutes 8 adapted to pass water between the outer sides of tube 1 and the radially inwardly directed sides ofthe bit.

As best seen in FIG. 2 the inside diameter of theE nects with the enlarged upper end portion thereof by an It fis' axially upwardly directed shoulder 10 (FIG. 5). the inner surface of the reduced diameter lower end p01'- tion of the bit thathas the utes 8 formed therein, and the depth of each flute is only a fraction of the width 0f the shoulder 10 (FIG. 5). Y A

The outer tube 3 is provided at its upper end with a head 11. This head is formed with a coaxial upwardly opening cylindrical `sided internally threaded recess 12 at its upper end, which is adapted to receive the lower end of the conventional drill pipe 13 that, in turn, is adaptedl to extend to the surface of the ground for connection vin the usual manner with means for transmitting downward pressure to the outer tube and for conducting water to the soil sampler, and for rotation of the outer tube.

The lower end of the pipe 13 terminates short of the lower end of recess 12, and a plurality of passageways 14 are formed in said head, extending divergently ydownwardly from the recess 12 andopening outwardly at their lower ends at the outer sides of the head (FIGS. 1, 4) at points spaced below said head.

The head'11 is threadedly secured inthe upper end 0f the outer tube 3 at a point intermediate the upper and lower ends of said head, and the outer diameter of the head is reduced below the threads that secure it to said outer tube, providing an annular passageway 15 between said outer tube and said head, which passageway is open at its lower end. The lower open ends of the passageways 14 open into said passageway 15.

The lower end portion of head 11 is centrally bored out to a point approximately midway -between the upper and lower ends of said head, as at 16, and is counterbored at 17 at the upper end of bore 16. Bores 16, 17 are coaxial with the head and with recess 12 that is in the upper end of the head.

A plurality of equally spaced fluid passageways 18 eX- tend divergently upwardly within head 11 from the counterbore 17 that is at the upper end of bore 16, which passageways communicate at their lower ends with said counter-bore, and with the outside of the soil sampler at their upper ends. Extending into the Ibore 16 and into the counterbore 17, is a vent tube 19 formed with an annular radially outwardly projecting flange 21 adjacent to, but spaced below its upper end, and which member is formed with external threads 22 at a point intermediate its ends.

, Within bore 16 between threads 22 and flange 21 are thrust bearings 23 that are held between nuts 20 on threads 22 and said ange, while a lluid seal 24 seals olf the upper end of the vent tube within the counterbore 17 against passage of iluid into bore 16. Thus the outerV tube including head 11 are rotatable relative to the vent tube.

The lower end of the Ihead 11 is closed by a centrally aperto-red plate 25 through the central aperture in which the vent tube rotatably extends, and below which the tube projects.

Screws 26 secure the plate 25 against the lower end of head 11, and said plate also ycarries a seal 27 coaxial with tube 19. This seal 27 is in a recess in the lower side of plate 25 and seals olf the lower end of the bore.

16 against passage of fluid into the. same at said lower end. a

A centrally apertured cap 29 is below the plate 25. The tube 19 extends through the central aperture in said cap and has an externally threaded lower end 30 that projects below the cap. A key 2-8 secures cap 29 rigid with tube 19. The outer cylindrical surface of said cap is slightly spaced from 'the inner sides of the outer tube 3 to permit passage of fluid through tube 3 past the outer surface o f cap 29.

An elongatedtubular member 31 is below cap 29, which member has a centrally aperturedV head 32, the aperture of Vlwhich is threadedly securedto the threaded lower end 30 of the vent tube 19.

The cap 29 is formed with'a recess in its lower side in which the upper end of the tubular member 31 is litted, and the sides 33 of said recess terminate in an annular axially :downwardly `directed surface around theV said upper end of member 31. Y Y

j The lower end of the tubular member 31 is open andY the surface of bore 34 in said member is tapered outwardly at the lower end of said bore, as at 35 (FIG. l). A vertically elongated, open end ed tubular element 36 is adapted to extend into the tubular member 31 through the lower open end of the latter. 'I'his element 36 is provided with a cup washer 38 at its upper end, that isV held on said tube 36by a nut 39 thereover (FIGS. 1, 2).

VThis element 36 is vertically reciprocable within the tubular member 31, and may move Ifrom the position shown in FIG. 1, in which its upper end is adjacent to the 4 head 32 of said member, to a position outside said member 31 and below the latter (FIG. 3).

The lower end of element 36 is secured within the central through bore 40 in a head 41. Said head is detachably secured to the upper end o-f the sampler tube 1.

The means for detachably securing the sampler tube 1 to head 41 may consist of centrally apertured, relatively thick circular disc 43 that is secured against the lower sur- `face of head 41 by screws 44, and said disc fits within the upper end of the sampler tubel. Screws 4S secure the tube Y1 to the disc, and consequently to the head 41 and to element 36.

By this arrangement sampler tubes of diierent wall thicknesses, but of the ysame outside diameter, may be used.

the lower face of the sides of cap 29 and the upper face of the head 41 is a strong helical spring 47.

When the soil sampler is lowered into a hole and the lower cutting edge of the sampler tube 1 is yagainst the bottom of the hole with the outer tube in its normal lower position at the commencement of an operation, the expanded or substantially Ifully expanded spring may be in approximately the position shown in FIG. 2 with a substantial length ofl the sampler -tube 1 projecting below the bit S. Thus the length of the expanded spring, as seen in FIG. 3 will normally be less than the length -to which the sampler tube 1 is adapted to project from the outer tube, as is seen in PIG. 3. Y

The lower edge of the sampler tube 1 is relatively sharp, lthe tube being beveled on its outer side, and the lower cutting edge projects radially inwardly slightly rela-V Vtive tothe inner sur-face of the sampler tube, which structure facilitates the loading operation.

Also, it is to be noted that the outer surface of the head 41 is formed withvertical, equally spaced ilutes 48 (FIG. 2) that may be the same number as the ilutes 8 in the bit, and the depth of these flutes is such -that when the lower shoulder y49 (FIG. 5) of the head 41 is against the upper shoulder 10 of the bitrS, ilow of iluid `from passagewayV 15 that is around the lower end portion of head 11, and from passageway 50 that is between the cap 29 and the outer tube 3 and that extends to the flutes in head 41 will not pass from flutes 48 to the flutes 8 in the bit. However, when the head `41 is spaced from the shoulder 10, uid will be `free to pass through utes 8 to -around the projecting end of the sampler Itube 1.

In operating during `the -lowering of the soil sampler the sampler tube 1 will be empty ,and in the position shown in FIG. 3. Water is normally supplied from pipey 13 under pressure Vfor passage through passageways 14, 15 and vent tube 36 to the inside ofthe sampler tube 1 and out of the latter, thus washing away loose material inthe bottom of the hole below the open lower end of the sampler tube. This is because the shoulders10, 49 (FIG. 5) will not permit the water to ow anywhere else than through the sampler tube.

As soon as the lower cutting edge of thejsampler tubeVV is seated against the bottom of the hole, the outer tube 3 will move down until the lower edges of sides 33 on cap 29 engage the upper end of the helical spring 47 (-FIG. 2). In this position the seal 38 on the upper end of the inner tubular element 36 will enter the bore in tubular member 31, and since the lower end of the sampler tube is sealed against the ground, the water entering the soil vsampler through pipe 13 lwill lilow through passageway 15 and will continue downwardly to pass through the flutes 48 in head 41 and through the flutes 8 in the cutter for ejection at the cutter, and the outer tube 3'including the drill `at its lower end will be revolved by conventionalk means at or above ground level, one such means being Y described in U.S. Letters Patent No. 2,403,002, issued to Henry L. Johnson, July 2, 1946.

The normal operating position is as shown in FIG. 2 in Disposed around the tubular member 31 and between which the sampler tube projects a substantial distance at its lower end outwardly of the bit 5, and under some soil conditions this spaced relationship between the cutting edge of the sampler tube and the cutting teeth of the bit may -be maintained as downward pressure is applied to the outer tube and is transmitted to the sampler tube through the spring 47. As the sampler tube moves downwardly and the soil fills the tube, the water above the soil is vented through the vent tube 19 and passageways 18, hence there is no water pressure on the soil in the tube other than that of the head above it.

Upon the sampler tube encountering harder material, added pressure will be transmitted to the core sampler as spring 47 is compressed, and the bit 5 will move downwardly toward the lower end of the sampler tube. The resistance may be such that, before the spring is compressed to the point shown in PIG. 1, the tube 11 will continue its downward movement. The bit may facilitate such downward movement even though it has not .reached the position shown in PIG. 1.

If the resistance to downward movement of the sampler tube be such that the spring 47 is fully compressed, the entire soil sampler will be rigid insofar as longitudinal movement of tubes 1, 3 is concerned and the teeth of the bit will cutaway the material around and below the sampler tube 1 permitting the hard material to enter the tube 1.

The slightly radially inwardly oifset position of the cutting edge of the sampler tube also prevents la binding or freezing of the material that enters the tube, such as may and has occurred where there is no such ofset.

In the position shown in FIG. l it should be noted that the water readily passes the flutes 8 in the bit for ejection to the cutting teeth.

Upon the tube 1 being filled with the sample, it is withdrawn and when the outer tube is elevated to the position of FIG. 3 the water yat utes 8 is sealed oif. by the engagement between shoulders 1G, 49 and the water will then be vented through the vent tube 19 and 4passageways 18 so that the material in the sampler tube 1 will not be atfected by water under pressure from the pump or hydraulic pressure system.

After the soil sampler is withdrawn, the inner tube 1 is removed from the outer tube by removing it from disc 43. A small amount of the material within the ends of the tube may be removed and the ends are then closed by wax or in any suitable manner and the tube of soil is then sent to the laboratory for examination.

Heretofore the obtaining of an accurate sample of soil where different degrees of hardness ranging from rock to relatively loose soil within the range of a sampler, has not been possible with `a thin wall or Shelby Type sampler. Also, as in thepatent hereinbefore mentioned, the soil sampler is rigid. There is a rotary cutter outside an inner tube, but they remain in a rigid position relative to each other longitudinally thereof and when hard material such as rock is encountered, the fact that the inner tube remains in a position projecting a substantial distance below the cutters renders the latter of no value.

In FIG. 1 I preferably provide a layer 51 of clay, such as bentonite, around the lower inner surface of the sampler tube 1 closely adjacent to the cutting edge. This material will be moved ahead of the soil along the sides and will preclude any likelihood of water entering the slight space that might exist due to the slight radially inwardly oifset cutting edge of the inner tube. This does not afyfeet the accuracy of the sample that is taken. Y

With the foregoing structure, the sampler tube 1 cannot possibly become stuck in the earth, as is many times the case where the sampler tube is merely pressed into the ground. The operation of the drill bit removing the material around the sampler tube prevents this occurrence.

Also in the present instance the removal of the material around the sampler ytube provides a sample of the harder soil within the tube that is not disturbed, because there is no outward displacement of material under pressure due to the volume of the tube. y Y

Such material as sandstone has been successfully included in a sampling operation by thin walled tube of sixteen gauge metal. 'I'he material that is around the cutting edge of the inner tube is readily sheared away as the cutting bit cuts the material around said cutting edge. y

It is to be understood that the detailed description and drawings are merely examples of the invention and are not to be considered as being limitations thereof.

I claim:

l. A soil sampler comprising: an elongated outer tube including an annular core cutting -bit on one end thereof and an inlet for liquid at its opposite end; an inner soil sampler tube within said outer tube and coaxial therewith supported for reciprocable movement within the latter longitudinally thereof between an extended position projecting through said bitra substantial distance outwardly of the latter and a collapsed position in which said sampler tube is enclosed within said outer tube with the one.

end thereof that is remote from said inlet being within said bit; said one end `of said sampler tube being formed with an axially outwardly directed, annular cutting edge; a passageway for liquid extending through said outer tube and bit outside said sampler tube for conducting liquid from said inlet tosaid bit for discharge at the latter when said sampler tube is in a partially collapsed position within said outer tube; first means within said outer tube carried thereby, second means carried by said sampler tube movable therewith into sealing relation with said first means-sealing said sampler tube against entry of said liquid into said sampler tube upon said movement of said sampler tube to said partially collapsed position and movable away from said first means to open said sampler tube to admission of said liquid into said sampler tube at the end of the latter that is opposite to said cutting edge When said sampler tube is moved to its said extended position.

2. A soil sampler comprising: an elongated outer tube including an annular core cutting bit on one end thereof and an inlet yfor liquid at its opposite end; means connecting said inlet with a source of liquid under pressure; an inner soil sampler tube within said outer tube and coaxial therewith supported for reciprocable movement within the latter longitudinally thereof between an extended position projecting through said bit a substantial distance outwardly of the latter and a collapsed position in which said sampler tube is enclosed within said outer tube with one end thereof that is remote from said inlet being within said bit; said one end of said sampler tube being formed with an axially outwardly directed, annular cutting edge and the opposite end of said inner tube being open; a passageway for liquid extending through said outer tube and bit outside said sampler tube .for `conducting liquid under pressure from said inlet to said bit `for discharge at the latter when said sampler tube is in a partially collapsed position within said outer tube; said opposite open end of said sampler tube being in communication with said passageway when said sampler tube is in its said extended position :for now of liquid from said passageway through said inner tube, sealing means within and carried by said outer tube engageable with said opposite end of said sampler tube upon movement of said sampler `tube `from said extended position to said partially collapsed position closing said opposite open end of said sampler tube to iiow of liquid from said passageway into said open end, means on said sampler tube at the end thereof that is opposite to said one end thereof and movable with said sampler tube [and means rigid with said outer tube at said bit movable into sealing relation upon movement of said sampler tube from its said partially collapsed position to its said extended position for closing said passageway at said bit to discharge of liquid from said passageway around said sampler tube at said bit.

3. A soil sampler comprising: an elongated outer tube including an annular core cutting bit on one end thereof and an inlet for liquid at its opposite end; an inner soil sampler tube within said outer tube and coaxial therewith supported for reciprocable movement within the latter longitudinally thereof between an extended position projecting through said bit a substantial distance outwardly of the latter and a collapsed position in which said sampler tube is enclosed within said outer tube with one end thereof that is remote rom'said inlet being within said bit; said one end of said sampler tube being formed with an axially outwardly directed, annular cutting edge; a passageway for liquid extending through said outer tube and bit outside said sampler tube for conducting liquid from said inlet to said bit for discharge at the latter when said sampler tube is in a partially collapsed position within said outer tube; rst means within said outer tube carried thereby, second means carried by said sampler tube movabl therewith into sealing relation with said first means sealing said sampler tube against entry of said liquid into said sampler tube upon said movement vof said sampler tube to said partially collapsed position and movable away from said first means to open said sampler tube to admission of said liquid into said sampler tube at the end of the latter that is oppositeV to said cutting edge when said sampler tube is moved to its said extended position, and means respectively carried bysaid sampler tube and said outer tube operative upon movement of said sampler tube to open said passageway at said bit to flow of liquid in said passageway through said bit when said inner tube is movedv toward said collapsed position from a fully extendedV position, and operative to close said passageway to low of liquid through said bit when,

said sampler tube is moved to its fully extended` position.

4. A soil sampler comprising: an elongated outer tube including an annular core cutting bit lon one end thereof and an inlet for liquid atrits opposite end; an inner soil sampler tube within said outer tube and coaxial therewith supported forV reciprocable movement within the latter longitudinally thereof between an extended position projecing through said bit a substantial distance outwardly of the latter and a collapsed position in which said sampler tube is enclosed within said outer tube with the one end thereof that is remote from said inlet being within said bit; said oneend of said sampler tube being formed with an axially outwardly directed, annular cutting edge; a passageway for liquid` extending through said outer tube and bit outside said sampler tube for conducting liquid from said inlet to said bit for discharge at the latter when said sampler tube is in a partially collapsed position within said outer tube; iirst means within said outer tube carried thereby, second means carried by said sampler tube movable therewith into sealing relation with saidl first means sealing said sampler tube against entry of said liquid into said sampler tube upon said movement of' tioned to engage said sampler tube and said outer tubey upon movement of said sampler tube to said partially co1- lapsed position for yieldably resisting movement of said inner tube to fully collapsed position.

References Cited in the le of this patent UNITED STATES PATENTS Re. 18,045 Baker Apr. 14, 1931 1,894,998 Macready Jan. 274, 1933 2,857,138 Svendsen et al Oct. 21, 1958 2,862,691

Cochran Dec, 2, 1958Y

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