US2809806A - Earth sampling tool - Google Patents

Description

Oct. 15, 1957 I c. c; LAVAL, JR

EARTH SAMPLING 'rooi.

Filed ,Sept. 13. 1954 I m/vm'roe I HUEBNER, BEEHLER,

v ATIORNEKSE wanna. & HERZ/G cuwnE a. LAVAL, JR.

United States Patent i The present invention relatesto geological apparatus of. the earth sampling character and.moreparticularlycto improvements in coring tool construction. and operation.

It is a conventional. practice to'obtain samplings ofsoil and rock formations prior to, or during, the performance.

of certain subterranean operations such as drilling wells for oil; water, gas, mineralsiorztheslike, during tunneling and mining operations; and'in preparation. fordanr and building construction where dependable foundations are. necessary. The well-known apparatus for obtainingsuch samplings generally consists of Such tools are lowered into a. bore hole or exploratory cavity in the earths surface and by hydraulic, explosive,

geared or some'other. pressure applying means,.the tools.

are driven into earth penetrating engagement. An apparatus of this natureis shown in a copending U. S. patent application 5.. N: 455,619, filed September 13, 1954.. Therein are discussed several problems encountered in' this field and the subject matter ofthat invention deals;

with improvements in the complete-sampling. apparatus. This application pertains to the sampling tools them:-

selves and theimprovementshereinafter. more fully-de1-- scribed are. adaptable to various types of samplingap;

paratus irrespective ofthe driving means and other details of associated structure employed. As noted inmy ucopending application cited above, conventional sampling tools have frequently been known to stick, jam, lockor. otherwise anchor in penetrated engagement in. an earth formation. Withsampling operations conductedatcon siderable depths, this represents a serious problem, resulting in damage of the samplingapparatus, breakage of sampling tools, jamming of the bore hole and sometimes complete. loss of the apparatus andi consequent plugging of the hole.

Another problem of considerableconsequence issample:

loss during withdrawal of the tool fromithe:hole.. In order to. counteract sample loss from the'tools subsequent to collection thereof andparticularly in those tools withdrawn. from the bore hole in dangling fashion, the interior of.

the conventional core-receiving barrel hasbeen contoured in such a way as to permit easy entry of the sample into. the barrel but to restrict its exit- Suchra feature is shown in the U. S. patent to Miller, Patent No. 2,334428:f This device employs serrations at the mouth of the barrel;

This structure has met with success insofaras'preventing sampling loss is concerned but has introduced an. addi.-'.

tional problem. When it is desired to remove the sample collected for inspection and analysis, the serrations: function equally as well to prevent convenient dislodge-- ment of the sample from the barrel. packed hard within the barrel and with rock' samples,

considerable prying, digging and scraping is necessary Oftentimes a sample becomes to extract the sample. jammed in the barrel and fracture of the toolisrnecessary to removeit. In other instances, the sample must he granulated for removal ,..tl1us reducing/theintelligencetov be gained by its inspection. This construction completely a cylindrical or similarly formed tool having a. sample-receiving barrel therein.

With samplings i prevents removal ofithe sample in the exact shapfirlt as, sumes in the barrel, a procedure sometimes found-des1r-- able.

Accordingly, an object of this inventionis to facilitate removal ofsampling tools from earth penetrating engagement thus minimizingt or. preventing sticking, jamming;

and inadvertent anchoring of such tools.

Another object is to provide an expendible coveringi member. between a sampling tool and earth penetrated; thereby adapted to remain in the earth during removal;

of the tool.

Another object is to reduce friction between a sampling tool and earth penetrated thereby.

Another object is tominimize the development ofa partial vacuum and the: consequent suction between an. earth penetrating member and the surrounding earth:

formation.

Another objectis to; provide anexpendible: sleeve: slid ably-fittedover a sampling tooladapted to remain in an,

earth formation when the: tool is removed.

Another object is to' minimize. the development of suction between the sleeve as provided in the foregoing paragraph and the. sampling tool during extraction thereof from earth penetrating engagement.

Another object: is to provide a device as set forth in: the preceding'paragraphs which in no way impedes thev sample collecting action of the sampling tool.

Another object istto facilitate removal of a sample from a sampling tool which is designed to prevent sample loss.

during removal thereof from a bore hole.

Another object is to provide asamplingtool having an. irregularly contoured" core-receiving barrel adapted to. minimizersample loss with convenient means for extrac tion'ofthe sample from the barrel.

Another object is toobviate the needfordigging, prying and scraping of collectedsamples from earth sampling Another object is to provide a sampling tool adapted: to permit removal of a sample in substantiallythe exact" shape and form collected.

Another object is to provide. a samplingutook which is separable:- into'aepluralityofi parts to permit: easy removal of samples therefrom.

Other objects are'totprovidel a. sampling toolinfaccord ance with the foregoing objects. which is simple .to manu.-= 1 facture; durable-in construction, readily adaptable ;to1many types of sampling; apparatus andwwhichprovides features.

highly-efiectivesfor-the intended purposes.

Theseand other objects: willbecomeimorefully apei parent upon reference to the following description: In. the drawings:

Fig. 1 is a longitudinal cross sectioni'takenthrougha. bore hole and. showingthe sampling tool ofthe present invention and suitable operating; mechanism therefor inserted therein.

Fig. 2iis asfragmentary longitudinal cross sectionsiinilarto Fig;' l but showing'a. diiferent operating mecha-- nism for thesam'pling tool.

Fig; '3 is a. somewhat enlargedxtransverse cross section?" taken through the"; sampling apparatus shown'i niFig. 1".

Fig. 4 is a view similar to Fig. 3 but showing=the=sam=-.

pling-tool'in itsi extendinglimitz'of operation'f Fig. 5 is aasomewhatj enlargedrlongitudinal cross: sec} tion taken through; the 'samplingtool' of Figs. 3= and Fig. 6 is. an: exploded: perspective; view of A the. sampling I.

tool. as provided by; the present invention;

Referring: more particularly to. the drawings: A sampling apparatus Ill-is. shown in. Fig. 1

The sampling apparatus provides a substantially cylin- Patented Oct. 15, 1957:

beinghelcl. by, a cable: 11 within; a; borehole 12- containing .fiuid. 13... This sampling: apparatus provides a. mounting. structure: for arpllllallfiY-Ofi$flI11P1lflglOO1S 14 h0l18fid therein;

drical housing 20 elongated in form and having enormi- V reeeivethe sampling too ls 14 for slidable reciprocationl between a retracted position within the chamber and a position extended from the housing, the latter position being that shown in Fig. l. V

Each of the ramming chambers 22 provides a closed end 30 and an open end 31 opening exteriorly of the housing 20. An annular nut 32 is threadably received in the open end of the chamber and provides a central bore 33 extending therethrough axially aligned with the chamber. 7

The sampling tool 14, as provided by the present invention, is best shown in Fig. 6. Its construction includes a pair of semi-cylindrical keyed segments 40 each having threaded ends, as 41. The segments are arranged in interfitted elongated tubular relation thereby defining an outer wall 42 and an interior core-receiving barrel 43. An annular nut 44 is threadably fitted on one of the threaded ends 41 of the interfitted segments hereinafter referred to as the penetrating or cutting end thereby maintaining them in interfitted relation. The outer wall 42 is inwardly directed at the penetrating end and is provided with a plurality of grooves or bores 45 constituting breather openings extending longitudinally therethrough.

The core-receiving barrel 43 is provided with a plurality of longitudinally spaced annular serrations, threads or ribs, indicated at 46. It will be noted that these serrations are convergently inclined from the penetrating end of the barrel toward the other end, conveniently referred to as the mounting end. The core-receiving barrel is adapted to receive therein a sample of an earth formation, such soil or rock, being slidably received over the serrations during its inward travel within the barrel. The sample is retained within the barrel because of the radially inwardly directed ridges on the serrations which prevent or restrict outward movement of soil or rock once having been received within the barrel.

A ram 50 is provided in the chamber 22 for slidable reciprocation between a retracted position adjacent to the closed end 30 of the chamber and an extended position adjacent to the open end 31 of the chamber. The ram includes a piston head 51 and an extended body portion 52 disposed toward the open end of the chamber. The body portion is provided at its end with a countersunk threaded bore 53. At the inner end of this bore 53, an annular passage 54 is provided. The body portion also has a longitudinal passage 55 permitting communication between the annular passage and the ramming chamber through the body portion. The body portion further provides an inclined passage 56 establishing communication between that portion of the chamber 22 behind the piston head and a position centrally disposed of the annular passage 54 and within the threaded bore 53. A ball check valve member 57 having a threaded plug 58 is fitted in the inclined passage 56 permitting the passage of gases and fluids only in a direction toward the ramming chamber adjacent the rear face of the piston head. The plug 58 is provided with a longitudinal bore permitting gaseous passage therethrough. The piston head is also provided with an ellipsoidal depression 59 concentrically arranged therein which also extends somewhat into the body portion 52.

The ram 50 is fitted onto the sampling tool 14 by threadably connecting the bore 53 on the mounting end of the interfitted cylindrical segments 40. In this position the longitudinal grooves 45 are aligned with the annular passage 54 in the body portion 52. Furthermore, the wall thickness of the cylindrical segments overlaps the annular passage 54 isolating the core-receiving barrel 43 of the tool from such annular passage. Thus, it becomes evident that the inclined passage 56 and valve 57 permit uni-directional gaseous passage from the core-receiving barrel to 'the ' mechanism 84 is the noses ramming chamber 22 rearwardly of the piston head 51.

With the ram 50 and separably constructed sampling tool 14 threadably connected, a sleeve or cap 65 providing a cylindrical portion 66 and an annular inwardly directed flanged end 67 is slidably fitted over the outer wall 42 of the cylindrical segments 40. The flanged end bears against the outer end of the cylindrical segments and closes off the longitudinal grooves 45 therein. It is to be understood that segments 40 can be held in fitted relation by the sleeve alone, that is, by forming the penetrating end without threads and eliminating the annular nut 44. In this event, the mounting end is still threadably connected to the ram so as to maintain the segments together when the sleeve is removed.

Thus, the ram 50, sampling tool 14 and sleeve 65' are adapted for unitary movement between a retracted position within the chamber, as shown in Fig. 3, and an extended position exteriorly of the housing 20, as shown in Fig. 4. A spring 75 is provided in the chamber encompassing the ram and sampling tool and bearing at opposite ends against the annular nut 32 and the piston head 51, respectively.

In its retracted position, the piston head 51 is spaced somewhat from the closed end 30 of the chamber 22. An explosive charge of powder or the like, indicated at 80, preferably a shaped charge, is placed within this space, also filling the ellipsoidal depression 59 in the piston head 51 and body 52. A frusto-conical nose 81 extends in an embedded position within the explosive charge and provides thereon a threaded fitting 82 for threadable insertion into an opening 83 in the wall of the housing 20. A spark gap firing pin or igniting also embedded within the explosive charge and a control wire 85 is connected to the firing pin for extension upwardly in mounting block 21. Suitable packing seals, not shown, may be provided to render Operation The operation of this invention is believed to be readily apparent and is briefly summarized at this point. Ini tially, all'of the sampling tools 14 provided in the housing 20 are urged into their retracted positions by their respective springs 75. The space behind the piston heads 51 are filled with explosive powder or charge and 82 by means of the threaded fittings 83 are screwed tightly in place in the housing wall 20. Thus, conditioned for operation, the sampling apparatus 10 is lowered into a bore hole or other cavity in the earth wherein it is desired to extract a sampling of the earth formation.

When the device is positioned at the desired level a switch, not shown, at the surface of the wall or some other convenient remote controlling station, is closed whereupon the control mechanism 90 is effective to ignite one of the firing mechanisms 84 associated with its respective sampling tool 14.

The explosion created behind the piston head 51 thrusts the ram together with the sampling tool 14 outwardly from a position such as that shown in Fig. 3

into its extended position, as shown in Fig. 4. During.

Each of the wires 85 lead into.

whereby the explosive gas pressures arewonfined within the ramming chamber 22* for desireddrivirig effect.

The force created by the explosion is'sufiiciently great tially the inner end of the barrel; it" is possiblethat air or other fluid may be trapped betweenthe inner end of the sample entering the barrel and the inner'end of the barrel itself. For this reason, thei nclined passage 56 has been provided. It will be quite evident that a sample entering the barrel will force fluid or gases captured-therein outwardly through the inclinedpassage and past the ball check valve member 57. Since this action only occurs at substantially the fully extended position of the sampling tool, and because of the rela tively high pressure of'the explosion during the expansion stroke of the sampling tool, there is little danger that;

the ball check valvemernber will open to release any of the explosive force built up behind thepiston head. It will be understood that an equalizing. of pressures between the barrel 43 and that portion of the rammingchamber 22 behind the piston head has little effect on the operation of the sampling tool if this equalization occurs at substantially the fully extended position of the tool.

When the tool has reached its fully extendedpositionand is ready for retraction-due tddissipatioii of the expl0-* sive charge and the urgence of spring 75, its emergence from the formation is rendered easier by the provision of sleeve 65. It will be apparent that the sleeve 65 has segments 40. On the retraction stroke of a the ramthesleeve remains in the formation and the sampling tool is slidably withdrawn therefrom. Thus, thesleeve acts as a liner between the earth formation and the outer wall 42 to reduce friction between the formation and the tool. However, in order to prevent a partial vacuum from developing between the sleeve 65 and the cylindrical segments 40, the groove 45, theannular passage 54,,v and the longitudinal passage 55 have been provided. Thus, there is an equalization of pressure between the ramming chamber 22 and the area between the sleeve65- and the end of the cylindrical segments 40. This pre-.

vents sticking between the sleeve and the cylindrical segments and greatly facilitates separation of these members during the retraction stroke.

After the sampling apparatus has; obtained a plurality of earth samples at a single testing-position or at a 'variety of depths, as the case may be, it is withdra wn from the borehole. At fittings 83 are removed and the tool forced out of the housing a distance permitting the cylindrical segments 40 to begrasped and unthreaded from the ram. The

segments, still containing a collected sample, .are then ready tobe taken 'to a laboratory or the like for removal and analysis of the sample or simple observation thereof.

For this purpose, the segments are separated from one a-sampling of the 7 formation is received within'the" barrel 43 and' passes- 11y extenddposition, and the the surface of the hole, the

t 6 plirfg'fto'ol constructed of separable segments, these problem's areobviated"quite easily. I

Afterlthe samples havebeen removed, the segments I are again pctsitionedtn ilitiffi tte'd relation and replaced in motintingfpositionwithin the ramming. chambers. Anew charge 'of explosive pbv'v'deris placed in the chambefahd' the apparatus is generally reset forsubsequent utilization;

Although the above descriptionpr'oyides a' sampling too1jfor';use"in aisarnpling'apparatus; such as shown at 10in'Fig. 1, the construction of the sampling tool'may be employed ina'samplingapparatusilw, such as shownin- Fig." 2f That is, deconstruction of the sampling tool including'sl'eeve '65" is not to'be limited to any particular rr'ieans" for 'dr'iving the tool into earth penetrating engagemam; Theapparatusisthe onesho'wnin greater detailin'my' copendingapplication S.-N. 454,543, filed on Septe'rnber7,1954. Briefly, it includes a housing 101'rnounted in a bore hole 102 and has amounting disposed-for slidable'reciprocationin the housing; A plurality 'ofsar'nplirigltdolslM are mountedon the body 103 and are adapted for outward pivoting movement throughsl'otsil05'in'th'e' housing, the-walls of the bore holean'd into grooves 106' disposed Withinthe niountingbody 103. The sampling tools 104 been driven into the formation along with the cylindrical 40' are constructedinthe'sanie"manner as the tools 14, pro viding' separable segm'ents, serrations on the core' receiving'barrelanda sleeve, a's107, in Fig. 2, slidably received on the connectedcylindrical segments. Pins 108 pivotally mounted-mute blockhavernounting' portions 109 thereonwhic'hprovfide threadedife'male bores for connection to the int'e'rfitted" segments iri'the same manner as ram 50 is connected tothesegr'nents', asseen'in Fig. 6. The operation'of these tools issir'nilar'tothat discussed in relation.

to Fig. l in that as the tools move in upward arcs through the soil formation the sleeves 107 are left in embedded position withinthe formationthus permitting easy withdraw'al of the'tools 'fromthe formation for movement into the grooves106.

v Although a cylindrical tool and cylindrical sleeve have been shown and described hereinabove, it will be app'arent thatjother' shapes such asrectangular, oval, triangular and the like may be used.

Other features which could' be incorporated in the various means-for embedding and retracting the tools of the presenfin'vention have not been shownin thedraw ing' for drafting simplicity and to emphasize the more significant-features ofthe p'resentinvention. However, asin my copending application, S. N. 455,619, filed on September 13, 1954', venting passages and cooperating. latch means may be'provided in the embedding and retracting apparatus, especially with that of Figs. 1"to 5 employing explosive drive means for the tool. Likewise, a separablesampling tool and anexpendible sleeve can be provided in a telescoping sampling tool, such as that shownin my copendng application S. N. 455,619, filed September 13, 19541 7 It-will be apparent from the foregoing description that' thepresentinvention provides featuresin a samplingtool' apparatus which ensure withdrawal of the tool from'the sampledformation and greatly facilitate removal of the sample from the tool. Both problems vhave limited the effective use of well-known sampling apparatus. The. present invention provides a simple, economical and readily adaptablemeans for solving theseproblems.

Although theinvention has been herein shown and described in what is conceived to be the most practicaland preferred embodiment,it is recognized that departures may be made therefrom within the scope of the invention,- which is notto be limited to the details disclosed herein butis to be accorded the" full scope of the claims so as to emb'race any and allequivalent devices and apparatus.

Haying described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A coringtool comprising an elongated tubular mem ber having amounting end portion and an opposite cutting body or block'103 in upwardarcs through I .dinally into separable elements,

end portion, the tubular member having a wall defining a core-receiving bore and having a breather opening longitudinally through the wall, and, a sleeve slidably fitted over the cutting end portion of the tubular member having an annular inturned edge endwardly overlying the cutting end portion of the tubular member and the open end of the breather opening therein.

2. A coring tool comprising an elongated tubular member having a mounting end portion and an opposite penetrating end portion, said member being divided longitudinally into separable elements, said tubular member having a breather opening longitudinally through an element thereof from the mounting end portion to the penetrating end portion, and a sleeve slidably fitted over the tubular member in circumscribing relation to the elements having an annular inturned flange outwardly overlying the penetrating end portion of the tubular member and the end of the breather opening therein.

3. A coring tool comprising an elongated tubular member having a mounting end portion and an opposite penetrating end portion, said member being divided longitusaid tubular member having a breather opening longitudinally through an element thereof from the mounting end portion to the penetrating end portion; annular means screw-threadably mounted in circumscribing relation on opposite ends of the tubular member constraining the elements thereof to their tubular arrangement; and a sleeve slidably fitted over the penetrating end portion of the tubular member in circumscribing relation to the annular means at said end and the elements of the member and having an annular inturned flange endwardly overlying the penetrating end portion of the tubular member and the end of the breather opening therein.

4. In a geological apparatus for use in sampling earth formations, a sampling tool comprising a substantially cylindrical member having an outer wall and an interior core-receiving barrel open at both ends, a plurality of bores extending through the wall of the cylindrical member open at both ends thereof, a mounting head releasably fitted on the cylindrical member in closing relation to one end of the barrel and having a passage providing communication between the bores in the cylindrical member and the exterior of the head, a sleeve providing a substantially cylindrical portion slidably fitted over the outer wall of the cylindrical member and having an inwardly flanged end fitted in closing relation to the bores at the opposite end of the barrel from the head, and means for urging the tool into penetrating engagement with an earth formation and for removing the tool from such formation.

5. A geological apparatus for use in sampling earth formations comprising a sampling tool having a pair of semi-cylindrical segments arranged in interfitted relation forming an exterior wall and an interior core-receiving barrel open at both ends, means releasably retaining the segments in barrel forming relation, a mounting head releasably fitted in closing relation on one end of the barrel, a. sleeve slidably fitted over the outer surface of the semi-cylindrical segments having an open end aligned with the other open end of the barrel, the barrel having a plurality of annular inwardly inclined serrations therein permitting inward movement but restricting outward movement of a sample relative to the barrel, the mounting head having a passage providing communication between the exterior of the head and the barrel, and means for extending the sampling tool into earth penetrating engagement and for retracting the tool from such engagement.

6. A geological apparatus for use in sampling earth formations comprising a sampling tool having a pairof semi-cylindrical segments arranged in interfitted relation forming an exterior wall and an interior core-receiving barrel open at both ends, the wallhaving a plurality of bores longitudinally extending 'therethrough, meansreleasably retaining the segments in barrel forming relation, a mounting head releasably fitted in closing relation on one end of the barrel and having an annular passage communicating with said bores, a sleeve slidably fitted over the outer surface of the semi-cylindrical segments having an open end aligned with the other open end of the barrel, the barrel having a plurality of annular inwardly inclined serrations therein permitting inward movement but restricting outward movement of a sample relative to the barrel, the mounting head having a first passage providing communication between the exterior of the head and the barrel and a second passage providing communication between the annular passage and the exterior of the head, and means for extending the sampling tool into earth penetrating engagement and for retracting a tool from such engagement.

7. A geological sampling apparatus comprising a body member providing a chamber therein, a sampling tool mounted in the chamber for reciprocation between a retracted position within the chamber and a position extended from the body adapted in the extended position to receive an earth sample, the sampling tool having a plurality of releasably connected interfitted fracto-cylindrical segments forming interiorly thereof a core-receiving barrel, the barrel having annular serrations therein permitting movement of the sample inwardly of the barrel but restricting outward movement of such a sample, a sleeve slidably received over the interfitted segments adapted to remain in embedded position within an earth formation during movement of the cylindrical segments from extended to retracted position, means yieldably urging the tool into retracted position, explosive means for thrusting the tool into extended position, and control means for firing the explosive means.

8. A sampling apparatus for insertion into earth cavities comprising a housing having a slot therein, a mounting member mounted for slidable movement within the housing past the slot and having a groove therein disposed for alignment with the slot, a sampling tool connected to the mounting member adapted upon registration with the slot for pivotal movement in an upward are through the earth formation adjacent thereto from a dependent position relative to the mounting member to an upright position within the groove of the mounting member, the sampling tool including a plurality of releasably connected interfitted fracto-cylindrical segments having an outer Wall and an interior core-receiving barrel, the barrel having a plurality of annular inwardly inclined serrations adapted to permit entry but restrict exit of a sample relative thereto, a sleeve slidably fitted over the outer wall of the segments adapted to remain embedded in an earth formation therebyfacilitating slidable withdrawal of the tool, and means for moving the mounting member toward the slot for registration of the tool therewith and for moving the mounting member past the slot to enable entry of the tool into the earth formation and for further movement into its upright position within the groove of the mounting member.

9. A coring tool comprising an elongated tubular member having an open mounting end portion and an open opposite penetrating end portion, the tubular member having a wall defining a core-receiving bore and having a breather opening extended longitudinally through the wall; a mounting head connected to the mounting end portion in closing relation thereto having passages providing communication between the exterior of the head and the breather opening; and a sleeve slidably fitted over the cutting end portion of the tubular member having an annular inturned edge endwardly overlying the penetrating end portion of the tubular member and the open end of the breather opening therein.

10. A coring tool comprising an elongated tubular member having a mounting end portion, an opposite penetrating end portion, a wall defining a core receiving barrel, and a breather opening extended longitudinally through the wall from the mounting end portion to the penetrating end portion; a mounting head releasably fitted on the penetrating end portion of the tubular member having a passage extended from the barrel to the exterior of the head and a passage extended from the breatther opening to the exterior of the head; and a sleeve slidably fitted over the tubular member in circumscribing relation to the tubular member having an annular inturned flange endwardly overlying the penetrating end portion of the tubular member and the end of the breather opening therein.

11. In a geological apparatus for use in sampling earth formations, a sampling tool comprising a tubular member having an outer wall and an interior core-receiving barrel open at opposite ends, a bore extended through the wall of the tubular member open at opposite ends of said member, a mounting head connected to the tubular member in closing relation to one end of the barrel and having a passage providing communication between the bore in the cylindrical member and the exterior of the head, a sleeve slidably fitted over the outer wall of the tubular member and having an inwardly flanged end fitted in closing relation to the bore at the opposite end of the barrel from the head, and means for urging the tool and sleeve into penetrating engagement with an earth formation and for removing the tool from such formation, the sleeve being slidably removable from the tool to remain in the formation.

12. A geological sampling apparatus comprising a body member providing a chamber therein, a sampling tool mounted in the chamber for reciprocation between a retracted position within the chamber and a position extended from the body adapted in the extended position to receive an earth sample, the sampling tool having a plurality of releasably connected segments forming'interiorly thereof a core-receiving over the interfitted segments adapted to remain'in embedded position within an earth formation during movement of the cylindrical segments from extended to retracted position means yieldably urging the tool into retracted position, and explosive means for thrusting the tool into extended position.

13. A sampling appartus for insertion into earth cavities comprising a housing having a slot therein, a mounting member mounted for slidable movement within the housing past the slot and having a groove therein disposed for alignment with the slot, a sampling tool connected to barrel, a sleeve slidably received 10 earth formation adjacent thereto from a dependent position relative to the mounting member to an upright position within the groove of the mounting member, a sleeve slidably fitted over the tool adapted to remain embedded in an earth formation upon withdrawal of the tool therefrom thereby facilitating slidable withdrawal of the tool, and means for moving the mounting member toward the slot for registration of the tool therewith and for moving the mounting member past the slot to enable entry tof the tool into the earth formation and for further movement into its upright position within the groove of the mounting member.

14. A coring tool comprising an elongated tubular member having a mounting end portion and an opposite cutting end portion, said tubular member having a core receiving bore extended longitudinally thereof from the cutting end portion, and a sleeve member slidably fitted over the cutting end portion of the tubular member, one of said members providing a breather passage having a breather opening at the cutting end portion of the tubular member and overlaid by said sleeve member during cutting operations to exclude foreign material from said breather passage. 7

15. A coring tool comprising an elongated tubular member adapted for longitudinal reciprocation during coring operations having a mounting end portion and an opposite cutting end portion, said tubular member having a core receiving bore extended longitudinally thereof from the cutting end portion, and a sleeve member slidably fitted over the cutting end portion of the tubular member having an annular inturned edge endwardly overlying the cutting end portion of the tubular member, one of said the mounting member adapted upon registration with the slot for pivotal movement in an upward are through the members providing a breather passage longitudinally therethrough in spaced relation to the core receiving bore and shielded from the core receiving bore by the tubular member, said passage having a breather opening overlaid by the inturned edge of the sleeve member.

References Cited in the file of this patent UNITED STATES PATENTS 1,529,734 Barbour et a1 Mar. 17, 1925 1,671,544 Raymond May 29, 1928 2,008,523 Thomas July 16, 1935 2,643,858 Hardman June 30, 1953 FOREIGN PATENTS 807,815 France Oct. 26, 1936

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