US1796488A

US1796488A - Earth-coring machine

Info

Publication number: US1796488A
Application number: US87249A
Authority: US
Inventors: Stone Frederick
Original assignee: DOHENY STONE DRILL CO
Current assignee: DOHENY STONE DRILL CO; DOHENY-STONE DRILL Co
Priority date: 1926-02-10
Filing date: 1926-02-10
Publication date: 1931-03-17
Anticipated expiration: 1948-03-17

Description

March 17, 1931. STONE 1,796,488

' EARTH GORING MACHINE Filed Feb. ,10, 192s` Patented Mar. I7, 1931 `munie STATES PATENT@ :OFFICE rnEnEaIcx STONE, or sroxANE, WASHINGTON, As'sIGNoaTo nonENY-STONE nml. oo.,l on Los ANGELES, cALIFoENIA, A CORPORATION or DELAWARE EABTH-COBING MACHINE Application mea February 1o, 192e. serial No. 87,249.

My present invention relates to an improved earth coring machine designed especially for the purpose of drilling in soft rock or similar material in the formation of and 5 procuring a large core recovery, in order that the strata through which the drill passes maycarefully and thoroughly be examined and analyzed. The improvements are direct-' ed particularly tothe parts of the tool that are subjected to greatest strain and wear, and therefore require continuous replacement, and means are employed especially for use in connection with-.the cutter head and cutting tools whereby the slush `or muddy circulating fluid are utilized to facilitate the operation of the cutters. rIhe drill bit or cutter is of the hollow .rotary type, employing diamonds, steel, or other abrasives on the face of the cutting head, and a core barrel or receiver for the core is carried above the cutter head for the reception of the core, which is formed by the advance movement of the tool. The :utter head is fashioned with circulating ports and connections for directing and controlling the flow of uid tothe cutters, for loosening,

softening and removing the dbris or sludge, and reventin vobstructions that are frequent y forme y the dbris.

Means are provided for facilitating and '30 insuring l ro rlow downwardly of fluid through t e interior of the tool by the use of ball valves controlling and directing the Huid into different channels of the tool after the core barrel. has been laced in working position in the hole, and or causing proper upward flow at the exterior of the tool to the ound level, carrying the sludge with the Hui 'Thecor'e in the formA of" a solid cylinder is cut by the rotary tool and received in 40 4the core barrel above the cutter head from which core barrel it is removed after the tool has been withdrawn vfrom the drilled hole, and the removal of successively drilled cores may be accomplished as the drilling or coring continues.

' threade In the accompanying drawings I have illustrated one complete example of the physi- A cal embodiment of my invention wherein the parts are comblned and arranged according f to the best mode I have thus far devised. for

ythe practical application of the principles of my invention, but it will be understood that changes and alterations within'the scope of my appended claims are contemplated, without departing from the principles of my invention.

Figure 1 is a broken view showing ex-l terior vand interior features of the coring device at the lower or drilling end thereof. v

Figure 2 is an enlarged vertical sectional view-of a portion of the lower endof the tool.

Figure 3 is a transverse sectional view at line 3-3 of Fig. 1.

Figure 4 is a transverse sectional 'view at line 4--4 of Fig. 1.

Figure 5 is an endyiew at line 5-5 of Fig. 1 with the cutters omitted from` the cutter head. Figure' is an enlarged exterior view' 4The cylindrical sleeve or outer tube 1 of the tool barrel is of suitable diameter and length for the erformance of its functions, and is on the lower end of the core barrelhead 2, to which the upper tubular sections of the coring tool are attachedas by tubular coupling 6a for the suspension and rotation of the tool. Coupling, 6a may thus be considered as representing a part of a usual hollow drill stem through the bore of which circulating fluid from the ground surface (not indicated) is adapted to be passed. The head 2 is preferably fashioned with an annular inclined seat 2a which forms a pocket for catching and retaining gravel that may fall down on the core barrel-head, as the tool is being lifted, andon its exterior face the barrel-head' i below seat 7 is fashioned with a suitable number of longi-k tudinal grooves 2b for water passages. The hollow barrel head is provided with a number of passages 3 which diverge downwardly from the valve chamber 4 which is a part of head hollow 4a, for the purpose of directing the flow of water into the interior of the sleeve or outer tube 1, and below this chamber the barrel-head is fashioned with a reduced central bore or vent chamber 5. The flow of fluid through this vent chamber is controlled by a pair of

spaced ball valves

6 and 7, the lower and smaller ball stopper 7 being seated at 7 on a seat provided in head 2; for instance, in the upper end or head 11 of an interchangeable nipple 8 which is threaded into the lower end of the barrel head. Valve stopper or ball 6 is adapted to seat at 9 on valve 10, as will be described. A laterally or radially extending vent 12 leads from chamber 5, at a point between seats 7 and 9, to the outside of head 2.

The upward pressure of gas is sometimes of such force as to lift both ball Stoppers 6 and 7 from their seats. In such event if both ball Stoppers were projected to positions above seat 9 and the larger ball 6 were then to be the first to find its seat, the smaller ball 7 would be prevented from reaching its seat. To

avoid this, several retaining springs 7a are provided in nipple 8 above seat 7 which springs project radially toward the 'center of the nipple bore. Spring fingers 7 a yield to permit ball'7 to find its seat when said ball is dropped from above but subsequently prevent upward movement of the ball to the undesired extent indicated above. However, fingers 7a permit ball 7 to rise sulilciently from its seat to allow direct communication between chamber 5 and the bore of nipple 8 The upper and larger ball stopper 6, shown in Fig. 1, coacts wit its' seat 9 in the upper end of a cage or slidable, tubular piston valve 10 normally supported in the upper end of vent chamber 5. The anged head 10b of valve 10 is provided with a packing ring 10a to lit in a complementary annular groove in' the barrel-head when said valve is in lowered position, while an annularfpacking 10d about the stem of valve 10 gives a fluid-tight fit with the wall of chamber. `Ball 7 is small enough to pass freely through the bore of valve 10.

By-passes 13 open at their upper ends to chamber 5 and at their lower ends to the bore of nipple 8 at points below seat 7. When valve 10 is in its uppermost position, as in Fig. 1, the upper en s of by-passes 13 are uncovered, while said valve, when it is depressed, is adapted to close said upper ends.

Before describing in detail the putting of the valve stoppers into position and the action of said Stoppers, li will first describe the rest of the tool structure.

At the lower end of the nipple 8 a cage 13 is fashioned for a normally open ball valve 13a which is retained in the cage by the use of a pin 13b'. Valve 13a permits free passage of relatively slowly moving fluid (such as that normally put under pressure by the slowly L advancing or incoming core as it is cut) through port 8, valve 7 chamber 5 and port 12 to the outer face of the core barrel, but a sudden rush or exceptionally large volume of fluid or dbris will act to lift valve 13a to close the lower end of the n ipple 8, and prevent the liquid and dbris from being forced upwardly into the nipple 8 from which it might pass and interfere with the functions of the

ball valves

6 and 7.

Below the barrel head a packing head 14n for` the upper end of the inner tube or core barrel 18, is slipped over the end of the nipple 8, and the packing head is provided with a stuffing box or gland 15 and thrust plates or disks 16 for permitting the outside tube 1 and the cutter head 17 to rotate freely, while the inside tube 18 or core barrel and its parts, remain stationary with the core. that is being fashioned. The number of thrust plates may be varied for the purpose of adjusting the length of the core-barrel assembly, and packing, as 19 is used in the packing head to insure a tight joint.

The barrel or receiver 18 for the c ore is a cylinder of less diameter than the outer tube 1 and it provides an annular space or water chamber 20 within the outer tube with which the diverging ports 13 of the barrel ,head communicate from above. The` inner tube or core barrel' 18 is threaded on the exterior of the packing head 14, as shown.

As will be later described, while cutter 17 is actually cutting, water flows from the diverging channels or ports 3 of the barrel head, over the packing head, on its way from the water chamber 4, to and through the annular water chamber 20, to the cutter head 17.

At its lower end the barrel 18 is exteriorly threaded to receive a tapered sleeve or core shell 21, and the core shell is surrounded by a coupling sleeve 22 of larger diameter, which at its respective ends is coupled by threads to the outer tube 1 and the cutter head 17. At its upper end the coupling sleeve is fashioned with an inner annular shoulder 23 for co-action with the lower end of the outer tube 1. The cutter head with its coupling sleeve 22 revolves around the stationary or non-rotatable core assembly, and a packing ring 24 is provided in an exterior annular groove of the depending flange portion 25a and a bearing ring 25, which ring is threaded on the lower end of the tapered core shell 21. Flange portion 25a has nice running t in the counter bore 256 of head 17. It will be noted that the 'core shell 21 and its rigid bearing ring 25 are the cutter head, and that there is provided a free turning vpacked joint 24 between rthe cutter head and bearing ring. l

The rotary cutter head which carries on its lower face the usual diamond, steel or other abrasive devices or cutters, is fashioned inY the form of an open ring having at its end the annular bearing groove or counter bore 25?) receiving the bearing ring 25, and it will be noted that the inner diameter of the bearing ring, which ring forms the lower end of the core shell, and the inner diameter-0f the cutter head are the same to insure a smooth, flush interior face for the wall that surrounds the core as it is being fashioned. This construction permits the core as it is being cut, to gradually work upwardly through the cutter head and' into the .core shell, and thence into the core barrel. 1

It will be observed in Figures land 2 that the core shell and the flush-inner wall of the upper portion of the bearing ring are of tapered formation to form annular tapered seats for a pair of

split rings

26 and 27 that are formed with teeth 28 which are adapted to bite into the exterior face of the core. The teeth are provided on spaced, wedge-shaped portions of the split resilient rings or

corelifters

26 and 27, and the teeth in each group are alined with the outer face of the cylindrical core to guide it and subsequently to ele- Vateit with the barrel as it is being formed.

The lower core-lifter 26 is limited as to upward longitudinal displacement by means of an annular shoulder 26 at the upper extremity of the annular seat for the ring. The upper split ring or core-lifter 27 is limited as to upward longitudinal displacement by means of a removable retaining ring 27 which is seated in an enlarged counterbore or annular groove 27a below the interior threaded face at the upper end of the core shell. The retaining ring is flush with the inner face of the inner tube or core barrel and frictionally engages the lower end of the barrel. The ring is clamped in its seat by screwing the tapered core shell over the lower end of the core barrel as best seen in Figure 2.

The lower core-lifter is fashioned with an upper annular extension 266 above the teeth 28, andthe upper core-flifter 27, which is smaller in diameter, frictionally engages the inner face of this extension and a portion of the fiush inner face of the core shell 21. In other words, the two lifters are arranged to be partially telescopic or longitudinally overlapping and it will be noted that the upper ring is in peripheral engagement at its upper end 26" with the bore defining wall'of shell 21 at a, point above shoulder 26. Said upper ring is thus` given peripheral backing and guided at both ends so as to be held against tilting about the axis of the barrel. The upper end of ring 26 may thus bea considered as giving peripheral backing to the lower end of ring 27. The llarger spaces above the core-lifters permit them to be expanded when'mov'ed thereto. The lower, resilient core-lifter'it will be understood is inserted in place from' below by first removin the bearing ring 25, and the upper core-liter is inserted from above through the upper end of the shell 21.

After the two cQre-lifters or split rings have been seated in the interior of the core shell they are retained in frictional contact with the core by'their resiliency or elasticity, and the co e lifters, due to their resilient properties, Ilightly clamp the core to maintain its stability,l and they remain in nonrotatable position with it in relation to. the cutter head. v

The core-

lifter

27 and 26 may be elevated, as the core is formed, until their upper edges contact with ring 27 and shoulder 26', re-

1 spectively. When the shell 21 is subsequently raised, the frictional contact between the core-lifters and the eore causes the litters to` be drawn down into their annular tapered sockets or seats, thus closing the teeth of the lifters on the face of the core.

In case smallpieces of rock or other d- ,bris should bind either or both of the split rings to their seats in the shell 21, the core barrel 18 and the core shell 21 remain stationary. By thus maintaining the core in non-rotatable position it is not subjected to fracture or of being ground to pieces. It will also be noted that the core, as it is be- ,ing fashioned, is kept free by

balls

6 and 7 from flow of water from above, and therefore is not subjected to the corrosive action of fluid or water which is being fed through the cutter head. At its lower edge or face the circular cutter head is fashioned with a suitable number of spaced undercut portions or open notches 29, which communicate with complementary, arcuate, circulating ports 30 in the wall of the cutter head, and these ports at their upper open ends communicate with an annular water chamber 31 between the `coupling sleeve 22 and the inner, tapered core shell 21. This annular chamber. receives the water flowing down through the complementary chamber 20 between the outer .tubev 1 and barrel 18 of the tool.

1GOA

As sho'wn in section in Figure 2 these circulating ports 30, which have upper enlarged openings 30', are not parallel with the interior face of the cutter head, but are positioned with their longitudinal axes at an angle to the axis Aof the cutter head. are arcuate or horizontally elongated as appears in Fig. 5. In Figure 7 it will be seen that the ports are widened at their inlet ends 30 and restricted at their discharge ends or lower ends, in order that a nozzle effect may be produced from the water vunder pressure as it passes from the chamber 31 into and' through the ports 30, the restriction of the` Ports 30 A ports at their lower ends also choking down the fiowof the mud-laden circulating fluid so it does not have as serious abrasive effect on the cutter-head about the relatively large inlet orices of the ports as would be the case if the ports Were of uniform diameter. is important that this abrasive action about the inlet orifices be reduced to a minimum since said orifices are close to packing 24 and the threaded connection between the head and sleeve 22. Any appreciable wear of the head stock at this point soon destroys the effectiveness of the packing and thread connection. On the other hand wear on the head adjacent the restricted portions of the ports has no seriously harmful effect. The particular shape of the ports is such that danger of clogging them with foreign matter is reduced to a minimum.

This discharge .of the water at the bottom of the hole adjacent the cutters, aids the cutters in their work, and dbris or sludge (cuttings etc.) flow outwardly from the ports and cutters through the lateral notches 29 of the cutter head.

At the exterior of the coupling sleeve 22 its face is fashioned with a suitable number of spirally arranged grooves. 32 that start from the respective notches 29 of the -cutter head and extend throughout the length of the sleeve, for passage of the cuttings or sludge which flow upwardly toward the ground surface.

The arrangement of

valves

6, 7 and 10 and the passageways controlled therebyis such that the fluid directing and controlling system may be put into effect by bringing the valves into play in any selected one of sev eral possible sequences. However, it will be understood that irrespective of the order of steps, the valve system is finally brought into the same operating condition before the actual cutting of the core is started.` l will outline several of these sequences in order to make this point clear..

Under certain circumstances it is not deemed necessary, while the tool is being lowered, to prevent fluid standing in the well hole from passing up through passageways 3 into the bore of drill stem 6a. In such a situation valve 10 may be manually depressed before the tool is lowered. Such depression of valve 10 puts chamber 4 in communication with the bore of stem Ga, seats flange 10a in counterbore 10c and closes off by-passes 13. With valve 10 thus depressed and

Stoppers

6 and 7 not yet inserted, the tool is lowered toward working position, there usually being no tool rotation nor fluid circulation set up during this lowering until the tool is a short distance from bottom, unless decided resistance, such as that resulting from a cave-in, is previously encountered. Such fluid as lies in the hole in the path of the lowering tool passes upwardly through passageways 30,

chamber 20 and passageways 3 to hollow 4a, and through the bore of barrel 18, nipple 8, vent chamber 5 and the bore of piston valve 10 to said hollow. From hollow 4a this fluid is free to pass into the bore of drill stem 6a. Under certain circumstances, depending upon the lowering speed and the consist- 4ency of the fluid within the well bore, ball 13a may rise and close off the bore of nipple 8 to prevent the upward passage of fluid through said nipple.

' When undue resistance is encountered or at least by the time the tool is within a short distance vof the bottom, rotation of and fluid circulation through stem 6a and the coring tool is established, the rotation stirring up and loosening the resisting dbris in the well hole and the circulation clearing the tool passageways of foreign matter and then preventing the stirred up dbris in the hole from entering said passageways. Thus, circulating fluid from above passes into hollow 4a whence part of it passes -downwardly through '

passageways

3, 20 and 30, while the remainder passes thro'ugh the bore of valve 10, vent chamber 5, the bore of nipple 8 and out through the bottom of the central bore in cutter 17. In other words, the circulating fluid serves to flush and keep clear all the tool passageways and bores mentioned above.

Preferably before the tool quite reaches bottom and after the passageways mentioned have been cleared, the relatively small ball stopper 7 is dropped through the stem bore whence it passes through hollow 4a, the bore of piston 10, vent chamber 5 and, s ringing fingers 7a', aside, comes to rest on seat Where it is held by fluid pressure from above. rEhe fingers 7a spring back in-to the retaining position for the purpose previously described. n

The reason for dropping ball 7 before the tool has quite reached bottom is merely to give ample time for the ball to drop so it may seat as soon as or shortly after the tool reaches bottom, and thus eliminate undue delay in starting the actual cutting of the core. Circulation may `still be maintained, as is desirable, for though ball 7 closes off the bore of the nipple and hence'of barrel 18, the fluid 1s still free to pass through passageways 3 and finally out through pasageways 30.

The relatively large ball stopper 6 is then dropped through the stem bore and comes to rest on its seat 9, where it is held by fluid pressure from above, said larger ball thus serving with ball 7 as a double seal against the entrance lof circulating fluid to the bore of barrel 18, allcirculating huid passing through passageways 3 and finally out passageways 30 to lubricate and flush cutter 17. Such circulation forces the dbris at the bottom of the hole upwardly about the outside of the Cor ing tool in the manner usual to all rotary cutting tools.

l will delay discussion of the action of the tor valve Stoppers during the cutting operation until I have discussed severalother orders of steps of putting the balls to their places.

It takes appreciable time for the balls to drop through a fluid-filled stem several thouJ sand feet in length, and the exact time the balls seat cannot be determined with perfect accuracy. As a safety caution, extra time is usually allowed before the cutting operation takes place, and this delay is sometimes undesirable to the operator for various reasons. In such situations the operator. may insert the smaller ball 7 within its cage before the tool is lowered, it thus being assured that said ball is in operating position by the time the tool has reached the bottom.

In such a case, before the tool is lowered, piston valve 10 is put in its uppermost position, as illustrated in F ig. 1, leaving bypasses 13 open at their upper ends and bringing the upper face of valve flange 10b in contact with the lower end of drill coupling` 6a. Said flange then prevents fluid and debris from passing upwardly through passageways 3 into the bore of the drill pipe as the tool is being lowered. Since the coupling bore is thus 'closed ofl:` from passageways 3 by the piston valve head and since valve 13a will close off the bore of nipple 8 from below if the tool is lowered beyond a certain speed or through mud-laden fluid of certain consistency, said valve head and valve stopper 13a serve as float-in .valves whereby the tool and supporting drill stem may be floated in through the fluid standing in the well hole and thus relieve the lowering' tackle (not shown) from a portion of the load strain.

As the'tool approaches bottom or when 'undue resistance is encountered, the tool is rotated as before described and circulating fluid i-s forced down through the drill stem. Such fluid passes through the bore of valve 10 into vent chamber 5, thence through bypasses 13 around ball 7 into the bore of nipple 8, and into and through the bore of barrel 18, which bore it flushes clear of dbris. The fluid then passes through the central bore in cutter 17 to flush the cutter and also flush out the bottom of the hole and clear the way for the descending tool.

When the flushing of barrel 18 is completed the larger ball 6 is dropped through the stem bore, circulation continuing through the path mentioned immediately above, said ball finally seating at 9 on valve 10. This larger ball closes oil the bore of valve 10 to prevent further Huid passage therethrough, and the fluid pressure from above then acts on the ball to. force piston 10 downwardly to a position closing the upper ends of by- Vpasses 13. Such valve movement also clears flange 10b from the under side of coupling 6a and the fluid from above is then free to pass through chamber 4, passageways 3, chamber 20 and thence through passageways 30 to and through the bottom of cutter 17 where it acts as a flushing and lubricating means for said cutter. The first rush of fluid through passageways 3 will, of course, clear said passageways, as well as chamber 20 and passageways 30, of any debris which may have gathered therein.'

In other situations it is desired to drop, the balls successively after the tool has been lowered, as in the rst situation described, and yet embody the feature of the second situation` that is, prevent the upward flow of fluid throu h passageways 3 into the stem bore, both igor the purpose of preventing the entrance of dbristo said bore and for the purpose of floating in the tool and stem. In such other situations the tool is sent down with neither ball in place but with piston valve 10 in its uppermost position as shown in Fig. 1. When resistance is encountered or the bottom of the hole closely approached the lower ball is dropped just as described in the first situation. In the first situation, however, piston valve 10 was down and accordingly circulation could be maintained through passageways 3 while the upper ball was dropping to place. In the present situation since ball 7 is closing the nipple bore and the .piston valve is up to put chamber 4 out of communication with the coupling bore, such circulation is maintained through bypasses 13 around the lower ball and thence through nipple 8 and the bore of barrel 18. As soon as the upper ball seats on valve 10 the latter is depressed by fluid pressure, as noted in the second situation, closing off bypasses 13 and putting passageways 3 into communication with the coupling bore through chamber 4a the fluid from above thus being entirely diverted from the bore of shell 18 to the space 20 between shell 1 and barrel 18 from which space the fluid passes through 'passageways 30 to lubricate and flush the cutter as well as flush out the well hole.

In all the above situations it will be'seen `that

ball valves

6 and 7 and valve 10v are alwavs finally put into the same position that is valve 7 is seated at 7', valve lO'is down in the position where it closes by-passes 13 and i opens chamber 4a to the coupling bore, and valve 6 is seated on valve 10 in a manner to close ofi' its bore.. It will be also noted that the arrangement is such that when cutting starts, vent 12 opens to the outside of the tool from a point between the vertically spaced and upwardly opening

valves

6 and 7 in the centralpassageway leading from the coupling bore to the bore of barrel 18.

I will now discuss the action of the several valves during the vcore cutting operation. The main purpose of the valve Stoppers is, of

course, to close the opening which has first been used to flush out the inner shell 18, so

the circulating fluid which is subsequently used during the cutting operation may not pass through this opening against the incoming core, which passage of fluid would seriously interfere with and usually absolutely prevent the taking of proper core', as will be readily understood. At the same time the valv'e arrangement is such that pressure raised in barrel 18 by the incoming core (either due to its natural progress or the practice of spudding to clear the cutter of dbris by reciprocating the tool vertically while a part of the core is in the barrel) is most elficiently relieved by being vented to the outside of the barrel, rather than to the Huid filled space above the valves.

ln order to point out how the two stoppers with the vent between them act together to render the tool'particularly efficient, assume rst that only the upper ball 6 be utilized, vent 12 being below seat 9. Ball 6 would then serve to divert all circulating fluid to passageways 3 and thus protect the core from such Huid, while pressure raised in the core barrel by the incoming core would be relieved through vent chamber 5 and vent 12 without disturbing ball 6 until the capacity of said chamber and vent has been reached. This feature of providing the barrel vent below a valve which holds downcoming fluid from enteringl the barrel, so that venting maybe accomplished without raising the valve is, so far as ll am aware, novel in the art and is of decided advantage since it does not necessitate valve movement or the holding of the valve in open position throughout periods of normal venting. Consequently this arrangemet reduces wear on the valve and lessens danger of fluid leakage from above.

However, it sometimes happens that the capacity of chamber 5 and vent 12 is not sulficient to accommodate the pressure raised within the core barrel, which would result in a lifting of ball 6. lf, during the time the ball is ofi the seat, dbris or small particles from the core lodge on the seat, the ball will be subsequently prevented from seating properly and the fluid under pressure from above would pass into chamber 5 and all that could not escape through vent 12 would pass directly into shell 18, with obvious undesirable effect.

rllhis condition is overcome by use of the lower ball 7, for even if ball 6 be held from its seat, ball 7 will prevent leakage from above from entering shell 18. Such leakage passesv out through vent 12. Though there is a possibility'of both balls being lifted from their seats with a subsequent lodgment of dbris thereon, the possibility of such double lo'dgment is remote so there is very little chance of both balls becoming ineffective. It will be seen that either of the balls, if seated` properly, will hold the fluid under pressure from above from entering barrel 18.

While the lower ball must move upwardly every time there is a relief of pressure from shell 18, it will be seen that the upper ball 6 relieves the lower ball of fluid pressure from above, and hence ,the lower ball will not be hammered t 0 its seat when the pressure is relieved from below. Also, by relieving the lower ball of pressure from above, said lower valve is enabled to respond more easily to pressure from below and there is consequently less danger of damaging the core by back pressure. In thus saving the lower ball and its seat from undue wear by hammering, the ball and seat are more easily maintained in condition to resist leakage from above which might arise by reason of the upper ball being oli' its seat or by reason of damage to said upper seat. Thus, the upper ball serves as a seal if the lower valve :becomes defective and relieves the lower ball of fluid pressure from above, while the lower ball serves as a seal if the upper valve leaks. The two balls thus contribute to a particularly eflicient venting of shell 18 and a particularly eicient protection of the core from the circulating fluid.

It will be seen that by-passes 13 are for the purpose of allowing circulation around ball 7 to Hush barrel 18 initially in a situation where said ball is sent down with the tool rather than dropped after the tool is lowered, and to allow continued circulation around said ball in a situation where said ball is dropped to seat in the event piston valve 10 is up against coupling 6a when the tool is lowered. In both situations it is necessary that the by-passes be closed when the upper ball is seated, to prevent any fluid, which may leak past said upper ball, from entering barrel 18 through said by-passes. As has been described, the stem of valve 10, in moving to depressed position under. the influence of fluid pressure on ball 6, functions to close the by-passes as soon as the need for them ceases. Valve 10 would serve this same purpose whether or not it closed off chamber 4a from the coupling bore when in it uppermost position. However, valve head 10a is adapted to have this chamber-closing function as an added feature, and when this feature is utilized, by-passes 13 take care of the circulation until depression of valve 10 allows circulation through passageways 3.

Of course, when the tool is lowered with neither ball in place and with valve 10 depressed there is no need for by-passes 13 since after barrel 18 is flushed and ball 7 is dropped circulation may continue through passageways 3. With this condition obtaining, the stem of valve 10 remains stationary throughout the operation, rendering bypasses 13 ineffective, and seat 9 may be considered as stationary with respect to head 2 and valve seat 7.

I claimrod, an outer tube and its barrel head having avent chamber, and an inner core barrel and its packing head, of a nipple joining said heads and fashioned with a cage, a ball valve in the cage, a valve cage forming a floating valve in the barrel head for co-'action with the drillrod, a valve in the latter cage,

' said vent chamber having a lateral portand a by-pass ,between the vent chamber and nipple.

2. The'combination with an outer tube and its barrel head having a water chamber and a vent chamber and a valve between said chambers, and an inner core barrel and its packing head, ofa nipple joining said heads and opening inthe vent chamber and a valve in said nipple below said chamber, said head having. ports between the water chamber and the interior of the outer tube, a lateral port from said vent chamber, and ay by-pass port between said chamber and the nipple opening below the lower valve.

3. The combination with an outer tube and its barrel-head having a water chamber and a `4tu'be, a lateral port from the vent chamber and a by-pass between the vent chamber and nipple, and selective means in co-operation with said chambers and ports for controlling and directing flow of liquid through the barrel head.

4. A1"n a core barrel, an inner and an outer tube, said tubes extending vertically and bel ing annularly spaced apart to provide an annular circulation chamber extending longitudinally therebetween, a ring-shaped core cutter at the lower ends of said tubes and extending across the lower end of said chamk, ber, there being a plurality of angularly spaced ports through thecutter at points isolated from said inner tube and opening at their upper ends to said chamber and at their'lower ends to the exposed end of the cutter, said ports being horizontally elongated and being of greater cross-sectional area where they open to the chamber than where they open to said exposed end.

5. In a core barrel, an inner and an outer tube, said tubes extending vertically and. being annularly spaced apart to provide an annular circulation chamber extending longitudinally therebetween, a ring-shaped core cutter at the lower ends of said tubes and ex` tending across the lower end ot said chamber, there being a plurality of angularly spaced' ort's through the cutter at points isolated rom said inner tube and opening at their upper ends to said chamber and at their lower ends to the exposed end of the cutter, said ports being horizontally elongated and being of greater crossctional area where they open to the cham er than where they open to said exposed end, said ports at their lower ends including inwardly land downwardly toward the barrel axis.

6. In a core barrel, a core shell having a 'plurality of internal, annular tapered seats,

a plurality of split, resilient core guiding and gripping rings, one in each seat, -eachring being externally taperedin complement to its seat and beinrr movable, between limits, longitudinally albng said seat, said rings being relatively movable vlongitudinally and be.

4ing in longitudinally overlapping relation throughout such relative movement whereby onering gives constant peripheral bearing to its overlapping ring;

7 In a core barrel for attachment to hollow drill stems, a tubular head, an inner tube and an outer tube supportedV by and extending vertically from said head, said tubes be-v 'ing annularly spaced apart to provide an annular circulation chamber extending longitudinally therebetween, said head having a valve chamber adapted to be in communication with the bore of the drill stem, there being ports extending between'said chambers, said head having a vent chamber adapted to be put in communication at its upper end with the drill stem bore, there being in the head a vertical passageway from the ventV chamber to the bore of the inner tube and a radial passageway opening from the vent chamber to the outside ofthe head, a valve. seat in said vertical passagewa there being avby-pass from said vent cham r and opening to the vertical passageway at a point bellowsaid seat, and a piston valvein the vent circulation chamber extending longitudinally therebetween,said head having a valve chamf ber adapted to be in communication `with the bore of the drill stem, there being ports extending between said chambers, said head having a vent chamber adapted tobe put in communication at its upper end with the drill stem bore, there being in the head a vertical passageway from the vent chamber to uthe bore of the inner tube and a radial passageway opening from the vent chamber to the outside of the head, a valve seat in said vertical passageway, there being a by-pass from said vent chamber and opening to the vertical passageway at a point below said seat, and atubular piston alve in the vent chamber and movable vertically and oppositely between limits to close and open the byfpass, said valve having a seat to take a stopper dropped through the stem to close one end of its bore. 9. In a core barrel for attachment to hollow drill stems, a tubular head, an inner tube and an outer tube supported by` and extending vertically from said head, said tubes being annularly spaced apart to provide an annular circulation chamber extending longitudinally therebetween, said head having a valve chamber adapted to be in communication with the bore of the drill stem, there being ports extending between said chambers, said head having a vent chamber adapted to be put in' communication at its upper end with the drill stem bore, there being in the head a vertical passageway from the vent chamber to the outside of the head, avalve seat in said vertical passageway, a valve stopper dropped through the drill stem bore, valve chamber and vent chamber to said seat, there being a by-pass from said vent chamber and opening to the vertical passageway at a point below said seat, and a piston valve in the vent chamber and movable vertically and oppositely between limits to close andA open the by-pass.

`10. In a core barrel for attachment to hollow drill stems, a tubular head, an inner tube and an outer tube supported by and extending vertically from said head, said tubes being annular-ly spaced apart to provide an annularv circulation chamber extending longitudinally therebetween, said head having a valve cham- I ber adapted to be in communication with the bore of the drill stem, kthere being ports ex tending between said chambers, said head having a vent chamber adapted to be put in communication at its upper end with the drill stem bore, there being in the head a vertical passageway from the vent chamber to the outside of the head, a valve seat in said verti-` ing a by-pass from said vent chamber and opening to the vertical passageway at a point below said seat, and a piston valve in the vent chamber and movable vertically' and oppositely between limits to close and open the by-pass.

1l. In a core barrel for attachment to hollow'drill stems, a tubular head. `an inner ,said head having a vent chamber adapted to be put in communication at its upper end with the drill stem bore, there being in the head a vertical passageway from the vent chamber to the bore of the inner tube and a radial passageway opening from the vent chamber to the outside of the head, a valve seat inv said vertical passageway, there being a by-pass from saidvent chamber and opening to the vertical passageway at a point below said seat, a tubular piston valve in the vent chamber and movable vertically and oppositely between limits to close and open the by-pass, and a valve stopper dropped through the drill stem bore, piston valve bore and vent chamber to said seat.

l2. In a core barrel for attachment to hollow drill stems, a tubular head, an inner tube and an outer tube supported by and extending vertically from said head, said tubes being annularly spaced apart to provide an annular circulation chamber extending longitudinally therebetween, said head having a valve chamber adapted to be in communication with the bore of the drill stem, there being ports extending between said chambers, said head having a vent chamber adapted to be put in communication at its upper end with the drill stem bore, there being in the head a vertical passageway from the vent chamber to the bore of the inner tube and a radial passageway opening from the vent chamber to the outside of the head, a valve seat in said vertical passageway, there being a by-pass from said vent chamber and opening to the vertical passageway at a point below said seat, a tubular piston valve in the vent chamber and movable vertically and oppositely between limits to close and open the by-pass, a relatively small valve stopper dropped through the drill stem bore, piston valve bore and vent chamber to saidseat, and a relatively large stopper dropped through the drill stem bore 1pid seating on the piston valve to close off its ore.

13. In a core barrel for attachment to a hollow drill stem, a hollow head, an inner tube and an outer tube extending vertically below said head, there being a vertical passageway from the head hollow to the bore of said inner tube, a valve seat in said passageway, a

valve stopper adapted to be dropped through` the drill stem bore to said seat, and resilient confining members extending radially inward above said seat, said members being adapted to yield to admit the stopper to its seat when so dropped and then to spring to a position permitting only limited upward movement of the stopper. x

14. In a core barrel for attachment to a hollow drill stem, a hollow head, an inner tube and an outer tube extending vertically below said head, there being a vertical passageway from the head hollow to the bore of said inner tube, a pair of vertically spaced valve seats in said passageway, a pair of valve stoppers adapted to be dropped successively through the stem bore one to each of said seats, and means thereafter preventing the stopper on the lower seat from rising through thetpassageway to a point above the upper sea 15. In a core barrel for attachment to a hollow drill stem, a hollow head, an inner tube and an outer tube extending vertically below said head, there being a vertical passageway from the head hollow to the bore of said inner tube, a pair of vertically spaced, annular valve seats in said passageway, a vent leading from said passageway at a point between the seats to the outside ofthe barrel, the upper seat being of greater diameter than the lower seat, and a pair of valve Stoppers, one fitting each seat, adapted to be dropped successively through the stem bore to their respective seats, the stopper for the lower seat being dropped first and being of a diameter to pass freely through the upper seat to said lower seat.

16. In a core barrel for attachment to a hollow drill stem, a hollow head, an inner tube andan outer tube extending vertically below said head, there being a vertical passageway from the head hollow to the bore of said inner tube, a pair of vertically spaced, annular valve seats in said passageway, a vent leading from said passageway, at a point between the seats to the outside of the barrel, the upper seat being of greater diameter than the lower seat, a pair of valve Stoppers, one fitting each seat, adapted to be dropped-successively through the stem bore to their respective seats, the stopper for the lower seat being dropped firstand being of a diameter to pass freely through the upper seat to said lower seat, and means adapted subsequently to prevent the lower stopper from passing upwardly through the upper seat.

17. In a core barrel for attachment to a hollow drill stem, substantially co-extensive vertically extending and annularly spaced inner and outer tubes,ithe inner tube -being mounted for rotation throughout its length with respect to the outer tube, the bore of the inner tubebeing initially in communication with the bore of the stem whereby fluid from within thestem bore may enter and flush the bore ofthe inner tube, and a valve stopper adapted to be' dropped through the stem bore to a predetermined position in said barrel, said stopper when in said position preventing further fluid flow from the stem bore to the bore of the inner tube and diverting said flow to the space between the two tubes.

18. In a core barrel for attachment-toga hollow drill stem, vertically extending and annularly spacedinner and outer tubes, the bore of the inner tube being initially in communication with the bore of the stem whereby iuid from within the stem bore may enter and flush the bore of the inner tube, and a pair of valve Stoppers adapted to be dropped successively through the stem bore to spacedapart, predetermined positions in the barrel, sald stoppers serving together to prevent further fiuid flow from the stem bore to the bore of the inner tube, there being a vent leading from between the Stoppers to the outside of the barrel.

19. In a core barrel for attachment to a hollow drill stem, substantially co-extensive vertically extending and annularly spaced inner and outer tubes, the inner tube being mounted for rotation throughout its length with respect to the outer tube, the bore of the inner tube being initially in communication with the bore of the stem whereby fluid from lwithin the stem bore may enter and flush the bore of the inner tube, and a valve member movable subsequently to a position to divert further fluid flow from the bore of the inner tube to the space between the two tubes.

20. In a core barrel for attachment to a hollow drill stem, a hollow head, the head hollow being adapted to communicate with the drill stem bore, an'inner tube and an outer tube extending below said head, there being a vertical passageway from the said head hollow to the bore of said inner tube, and a normally open valve in said passageway, said valve being adapted to be closed by virtue of predetermined pressure from within the inner tube. v

21. In a core barrel for attachment to a hollow drill stem, a hollow head, an inner tube and an outer tube extending vertically below said head, there being a vertical passageway from the head hollow to the bore of said inner tube, a normally open valve in said passageway, said valve being adapted to be closed by virtue of predetermined pressure from within the inner tube, there being a vent leading from said passageway at a point above said valve to the outside of the barrel, and a second,rnormally closedvalve in said passageway at a point between the vent and the first mentioned valve.

22. In a core barrel for attachment to hollow drill stems, a tubular head, an inner tube and an outer tube extending vertically from said head, said tubes being annularly spaced apart to provide a circulation chamber e x tending longitudinally therebetween, said head having a second chamber adapted to be put into communication with the drill stem bore, there being ports extending between said chambers, there being in thehead a vertical passageway from the drill stem bore to the bore of the inner tube, a valve in said passageway and normally closing it off, there being a by-pass from the passageway above the valve to the passageway below the valve, and a vertically movable piston in the head, said piston, in one position, being adapted to put the second chamber out of communication with'the stem bore and to leave said by-pass open, and being movable to another position in'which it allows communication between the drill stem bores and second chamber and closes said 'byass.

23. In a core barrel lor attachment to hollow drill stems, a tubular head, an inner tube and an outer tube extending vertically from said head, said tubes being annularly spaced apart to provide a circulation chamber extending longitudinally therebetween, said head having a second chamber adapted to be put into communication with the drill stem bore, there being ports extending between said chambers, there being in the head a vertical passageway from the drill stem bore to the kbore of the inner tube, a valve in said passageway and normally closing it 0E, there being a by-pass from the passageway above the valve to the passageway below the valve, and means for opening and closing said byassn p 24. In a core barrel for attachment to hollow drill stems, a tubular head, an inner tube and an outer tube extending vertically from said head, said tubes being annularly spaced apart to provide a circulation chamber extending longitudinally therebetween, said head having a second chamber adapted to be ut into communication with the drill stem ore, there being ports extending between said chambers, there being in the head a vertical passageway from the drill stem bore to the bore of the inner tube, a valve in said passageway and normally closing it off, there being a by-pass from the passageway above the valve to the passageway below the valve, means for putting the second chamber out of communication with the drill stem bore, and means for closing said by-pass when the second chamber is in communication with the drill stem bore.

25. In a core barrel for attachment to a hollow drill stem, a hollow head, an inner tube and an outer tube extending vertically below said head, said tubes being annularly spaced apart to provide an annular circulation chamber extending longitudinally therebetween, there beine' a passageway from the head vhollow to said chamber and a second passageway extending vertically from the head hollow to the bore of said inner tube, a pair of valve seats in said second passageway, said seats being vertically spaced apart, there being a vent leading from said second passageway at a point between said seats to the exterior of the barrel, and a pair of valve Stoppers, one on each seat, normally closing said second passageway, one at a point above and the other at a point below said vent.

26. In a core barrel for .attachment to a hollow drill stem, a hollow head, an inner tube and an outer tube extending vertically below said head, said tubes being annularly spaced apart to provide an annular circulation chamber extending longitudinally therebetween, there being a passageway from the head hollow to said chamber and a second passageway extending vertically from the head hollow to the bore of said inner tube, a pair of valve seats in said second passageway, said seats being vertically spaced apart, there being a vent leading from said second passageway at a point between said seats to theexteriorof the barrel, a pair of valve Stoppers, one on each seat, normally closing said second passageway, one at a point above and the other at a point below said vent, and a normally open valve movable upwardly to close the second passageway at a point below said pair of seats.

27. In core barrel for attachment to a hollow drill stem, vertically extending and annularly spaced inner and outer tubes, the bore of the inner tube being initially in communication with the bore of the stem whereby luid from within the stem bore may enter and flush the bore of the inner tube, a valve member adapted initially to prevent fluid ow from the space between the two tubes to the drill stem bore, and a valve stopper adapted to be drop ed through the stem bore to a predetermined position/in said barrel, said stopper when in said position preventing further fluid flow from the stem bore to the bore of the inner tube and, under the influence of Huid pressure from above, moving said valve member to allow fluid flow from the stem bore to the space between the two tubes.

y 28. In a core barrel for attachment to a hollow drill stem, vertically extending and annularly spaced inner and outer tubes, the bore of the inner tube being initially in communication with the bore of the stem whereby fluid from within the stem bore may enter and flush the bore of the inner tube, a valve member adapted initially to prevent fluid flow from the space between the two tubes to the drill stem bore, and a normally open valve adapted to be closed by virtue of predetermined pressure within the bore of the inner tube, said last mentioned Valve, when closed, preventing fluid flow from the bore of the inner tube to the drill stem bore.

29. In a core barrel for attachment to a hollow drill stem, vertically extending and annularly spaced inner and outer tubes, there being a passageway between the stem bore and Jthe space between tubes, there being a second passageway between the bore of the inner tube and the stem bore, a valve member adapted initially to prevent fluid flow from the space between tubes to the drill stem bore, and a normally open valve in the second mentioned passageway adapted to be closed by virtue of predetermined pressure within the inner tube.

30. In a core barrel for attachment to a hollow drill stem, avhollow head, the head hollow being adapted to communicate with the drill stem bore, an inner tube and an and relatively rotatable,

hollow being adapted -of said nipple forming a passageway from the head hollow and hence the stem bore to the bore of the inner tube.

31. In a core barrel for attachment to a hollow drill stem, a hollow head, the head hollow being adapted to communicate with the drill stem bore, an inner tube and an outer tube extendingl vertically below said head, said tubes being annularly spaced apart a head for the upper end of the inner tube, a nipple extending from the hollow head into said tube head with rotational lit for centering the inner tube within the outer tube, the bore of said 1nipple forming a passageway from the head hollow and hence the stem bore to the bore of the inner tube, and a core catcher sup ported by said inner tube.

32. In a core barrel for attachment to a 'hollow drill stem, a hollow head, the head hollow being adapted to communicate with the drill stem bore, an inner tube and an `outer tube extending vertically below said head, said tubes being annularly spaced apart and relatively rotatable, a head for the upper end of the inner tube, a nipple extending from the hollow'head into said tube head with rotational lit for centering the inner tube within the outer tube, the bore of said nipple forming a pass-agewa from thehead hollow and hence the stem ore to 4the bore of the inner tube, and `means for rotatably supporting said inner tube from vbeneath near its lower end.

33. In a core barrel for attachment to a hollow drill stem, a hollow head, the head to communicate with the drill stein bore, an inner tube and an outer tube extending vertically belowsaid head, said tubes being annularly spaced apart and relatively rotatable, a headfor the upper end of the inner tube, a nipple extending from the hollow liead into said tube head with rotational fit for centering the in ner tube within the outer tube, the boreof said nipple forming a passageway from the head hollow and hence the stem bore to the bore of the inner tube, a core catcher supported by said inner tube, and means for rotatably supporting said inner tube from beneath near its lower end.

34. In a core barrel for attachment toa hollow drill stem, 'a hollow head, the head hollow being adapted to communicatewith the drill stembore, an inner .tube and an outery tube extending vertically below said head, said tubes being annularly spaced apart and relatively rotatable, a head for the upper end of the inner tube, a nipple extending from the hollow head into said tube head with rotational fit for centering the inner tube within the outer tube, the bore of said nippleI forming a passageway from the head hollow and hence the stem bore to the bore of the inner tube, and a valve for controlling fluid passage through the nipple bore.

In testimony whereof I afHxed my signature.

FREDERICK STONE.

CERTIFICATE OF CORRECTION.

Patent No. i,796,4ss. l Granted March 17, 193i, to

FREDERICK STONE.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2, line 122, strike out "25a' and" and insert instead 25a of; page 3, line 83, for "core-lifter" read core-lifters; page 7, line 67, claim 5, for "including" read inclining'g; page 9, line 90, claim 211, after the word "extending" insert the word vertically, and line 91, strike out the word "vertiea1"; and that the said Letters Patent should 'be read with these vcorrections therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 7th day of July, A. D. 1931.

M. J. Moore, (Seal.) Acting Commissioner of Patents.