US3005504A

US3005504A - Drilling device

Info

Publication number: US3005504A
Application number: US812330A
Authority: US
Inventors: Jr Herman W Mayhew
Original assignee: Gardner Denver Inc
Current assignee: Gardner Denver Inc
Priority date: 1959-05-11
Filing date: 1959-05-11
Publication date: 1961-10-24
Anticipated expiration: 1978-10-24

Description

Oct. 24, 1961 H. w. MAYHEW, JR 3,005,504

DRILLING DEVICE Filed May 11, 1959 3 Sheets-Sheet 1 63 INVENTOR Herman W. Mayhew,Jr.

ATTORNEY Oct. 24, 1961 H. w. MAY-HEW, JR

DRILLING DEVICE 5 Sheets-Sheet 2 Filed May 11, 1959 Q A KS, 4 ///flflfl/ m m INVENTOR Hermon W.Muyhew, Jr.

Oct. 24, 1961 H. w. MAYHEW, JR

DRILLING DEVICE 3 Sheets-Sheet 3 Filed May 11, 1959 INVENTOR Hermon W. M0yhew,Jr.

BY ME ATTORNEY United States Patent 6 3,005,504 DRILLING DEVICE Herman W. Mayhew, Jr., Dallas, Tex., assignor to Gardnet-Denver Company, a corporation of Delaware Filed May 11, 1959, Ser. No. 812,330 16 Claims. (Cl. 175-200) This invention is concerned with a drilling device for drilling holes into the earths strata and is particularly concerned with a drilling device having a drill stem made up of concentrically arranged and slidably related tubular members which may be disengagably keyed together for rotation wherein the inner tubular member may be withdrawn from the outer tubular member to permit the outer tubular member to remain in the hole to serve as a casing for the hole while explosives or other instruments are lowered into the hole.

This application is a continuation-in-part of patent application Serial No. 652,989 (series of 1948), now abandoned, filed April 15, 1957, by Herman W. Mayhew, Jr., Drilling Device.

In quarrying operations and geophysical exploration it is the practice to drill a hole into the surface of the earth and lower into such hole an explosive charge which is detonated to break up the substance to be quarried, or to supply a detonating impulse for recordation of geophysical information.

It has been the practice in the past to withdraw the entire drill stem from the hole prior to lowering the explosive charge therein, and the explosive charge was usually lowered into the open hole on wires or cables extending from the surface.

In many areas where such operations are carried-onthe formations of the earth through which the hole is drilled are of loose, crumbly nature so that when the drill stem is withdrawn from the hole the walls of the hole often crumble and slough off, thereby partially filling the hole and making it ditficult, if not impossible, to lower the explosive charge into the hole, thereby resulting in added expense and time to the operator in carrying out such operations.

The present invention comprehends a drilling device which permits the operator to lower the explosive charge through a casing or liner, which is a part of the drill stem, so that the walls of the hole cannot cave in to prevent the lowering of the explosive charge therein.

The invention includes concentrically arranged and separately raisable drill pipes, each having a drill bit thereon, so that the outer drill pipe may be left in the hole when the inner drill pipe is withdrawn to provide a cased hole through which explosives and other devices may be lowered into the hole.

The separately withdrawable drill pipes. are keyed or splined together for rotation in unison so that the two drill pipes, when so keyed together, perform the function of a single drill stem.

Thus this device assures a free passage to the bottom of the hole for lowering explosives and other objects therein.

It is therefore a primary object of this invention to provide a drilling device which permits the operator to lower explosive charges into the hole through a tubular casing forming a part of the drill stem.

Another object of this invention is to provide a drilling device for quarrying and geophysical exploration which results in a great saving in time and expense to. the operator.

A still further object of the invention is to provide a drill stem having concentrically arranged and slidably related tubular parts which may be keyed together for unitary rotation but which are separately withdrawable from the hole.

' a bore hole 15 therein.

An additional object of the invention is to provide a drill stem made up of concentrically arranged tubular.

members wherein the inner member may be withdrawn FIGURE I is a side elevational view showing one emr bodiment of the drilling device mounted on the frame of a truck, with the drill stem extending-into a hole which has been drilled in the earths surface;

FIGURES II, III andIV show a fragmentary, partially sectionalized, elevational view of a drilling device incorporating the invention disclosed herein, said view illustrating the concentrically arranged and separately raisable drill pipes, keyed together to rotate as a single drill.

stem;

FIGURE V is a cross-sectional view taken on the line VV of FIGURE III;

FIGURE VI is a cross-sectional view taken on VI--VI of FIGURE II;

FIGURE VII is a bottom plan view of the drill bit-attached to the lower end of the inner drill pipe;

FIGURE VIII is a bottom plan view ofthe drill bit attached to the lower end of the outer drill pipe;

FIGURE IX is a cross-sectional, elevational view of a modified. form of. spindle and adapter head showing a. bayonet joint type of connection between such members;

FIGURE. X is a transverse sectional view taken on the line X-X of FIGURE IX;

FIGURE XI is a side elevational view, showing the bayonet joint connection between the spindle and the adapter head.

In the drawings numeral references are employed to indicate the various parts shown, and like numerals indicate like parts throughout the various figures of the drawings.

vIn FIGURE I is shown a suitable form of mast 10 to support the drill stem as it is rotated to penetrate the earth to form a hole therein, and to provide a supporting frame for raising and lowering the drill pipes, as will be hereinafter described.

The mast 10 may take dilferent forms, but it is preferably mounted on a truck 24 or trailer for the purpose of vide such feature the opposite legs of the mast 10 may be pivotally mounted to the truck frame 13 by means of pivot bolts 11 and when in upright position, as shown in the drawing, it may be detachably secured to the truck frame by means of a bolt and nut 12, or by other suitable detachable securing means.

The drill stem, indicated generally by the numeral 14;

is made up of concentrically arranged and slidably re,

lated tubular members which are keyed together for rota f tion in unison, as will be hereinafter described. As shown in FIGURE I, the

drill bits

67 and 74, attached to the lower ends of the concentrically arranged drill pipes, have been rotated to penetrate the earths strata 16 to form The drill stem 14 slidably extends through, and is keyed to, a rotary table 18, rotatably attached to the frame 13 of the truck, the drill stem 14 being keyed to the rotary table 18 for rotation therewith by means of a drive bushing as- I sembly 17, which will be hereinafter described in detail,

the line The rotary table 18 may be rotated in any suitable manner as by a drive chain 1'9, extending thereabout, from power supplied by a power unit 20, mounted on the truck 24. The drive chain 19 may be rotated to drive the rotary table 18 through a gear train driven from the power take-01f 25 of the power unit 20, such gearing being illustrated as articulating bevel gears 21 and 22 which drive a horizontally disposed sprocket 23, about which the drive chain 19 is arranged.

The drill stem 14 may be suspended to the mast it by nieans of a cable 29 attached to the bail 26, the ends of said bail being pivotally attached on opposite sides of the rotary spindle 27.

The cable 29 is wound and stored about a rotatable drum 30 mounted on the truck frame 13, said drum being rotatable by means of a belt 31 which is driven by a suitable power take-off (not shown) of the power unit 20.

The cable 25 extends about a sheave 32, which is rotatably mounted at the upperend of the mast it). A hook 33, attached to the end of the cable 29, is engaged with the bail 26 to thereby suspend and support the drill stem 14, and by which the outer drill pipe 65 may be raised out of the hole 15 in the manner hereinafter described.

Another cable 34 is wound and stored about a drum 4d, rotatably mounted'on'the truck frame 13, which drum may be rotated by a drive belt 41 from a power take-01f (not shown) of the power unit 20.

The cable 34 extends about a sheave 35, rotatably attached at the upper end of the mast 10.

A hook 36, onrthe end of the cable 34, may be attached tothe eye 37, provided on the rotary swivel 28, for the purpose of withdrawing'the inner drill pipe 64 from the outer drill pipe 65 in the manner which will be hereinafter described.

V A fluid circulating hose 38 is attached between the rotary swivel or circulating head 28 and a pump 39, mounted on the truck frame 13. Suitable circulating fluid, such as liquid or air, may be forced through the hose 38, the circulating head 28, and downwardly through the inner tubular member 64 of the drill stem 14 to thereby provide fluid circulation through the drill stem 14 and upwardly through the. annular space between the wall of the bore hole 15 and the drill stern as drilling is progressing.

Referring to FIGURES II, III and IV, which show the concentrically and slidably arranged tubular members making up the drill stem 14, the annular spindle body 42 is rotatably mounted on upper and lower roller bearings 43 and 44. The bearings43 and 44 are maintained in assembled position about the spindle body 42 by means of a bearing retainer ring 45 and a spacer sleeve 45a, arranged about the spindle body 42.

The bearing retainer ring 45 has diametrically opposed

ears

46 and 47 arranged on the outer side thereof about which ears the free ends of the bail 26 are pivotally attached to thereby provide'means for hingedly supporting the drill stem. 7

Upper and lower fluid seals 48 and 49 are disposed between the bearing retainer ring 45 and the spindle body 42. to maintain lubricating fluid in the reservoir 54 of the b'earing'assembly. The bearings 43 and 44, and retainer ring 45, are held in assembled position with relation to the spindle body 42 by means of a retainer nut 54 which is threadedly engaged about the lower end of the spindle body 42, the retainer nut 50 being held in place against rotation by means of a set screw 51 which passes through the retainer nut 50 and penetratingly contacts the spindle body 42; g

It will be seen that the spindle body 42 may rotate on thebearings 43 and 44 as the drill stern, attached thereto, is rotated.

- A lubrication supply passage 52 extends through the ear 46 and may be closed at its outer end by a removable plug 53. Suitable lubrication fluid may be supplied to the lubricant reservoir 54, in the bearing assembly, through the passage 52.

An insertable and withdrawable inner adapter head 56 is slidably disposed in the spindle body 42, the said adapter 56 having an enlarged head 57 thereon which is arranged to come into mating contact with the upper end of the spindle body 42 to thereby suspend the adapter head 56 in the spindle body 42.

An upwardly extending attachment neck 55 is provided on the adapter head 56, which neck 58 is threadedly engaged at its upper end to the rotary swivel 28.

The rotary swivel 25 is detachably secured to the hose 38 by a coupling 38a.

The rotary swivel 28 is of conventional construction, having a fluid passage (not shown) therethrough, and includes a tubular part 55 which is rotatable, in sealed engagement, with reference to the main body of the rotary swivel 28. As the drill stem 14 is rotated the tubular part 55 rotates with respect to the main body of the swivel 28. Drilling fluid is circulated through the hose 5% and the rotary swivel 28 into and through the inner pipe 64 of the drill stem 14 and upwardly through the hole 15 to the surface.

A concentric flow passage 59 is provided through the inner adapter 56 whereby fluid may be circulated through the rotary swivel 28 and downwardly through the inner tubular member 64 of the drill stem.

A plurality of longitudinal keys or splines 60 are formed, in spaced relationship, about the outer side of the inner adapter 56, said keys being arranged to be inserted in coinciding key channels 61, formed on the inner side of the spindle body 42. The keys 66 are slidably inserted in the key channels 61 so that the inner drill pipe 64, attached to the adapter 56-, may be drawn upwardly out of the outer driil pipe, but said keys 6% and key channels 61 disengagably key the inner drill pipe with the outer drill pipe, whereby they may be rotated together, v

After the inner adapter 56 has been inserted in the spindle 42 with the keys 6%) and key channels 61 in mating relationship, a hammer nut 62 may be threadedly engaged about the upper end of the spindle body 42, in engagement with a shoulder 57a on the head 57 of the inner adapter 56, in order to disengagably attach the inner adapter 56 in the'spindle body 42.

The hammer nut 62 has hammer lugs 63 spaced thereabout which may be struck by a hammer or-other instrument to rotate the hammer nut to thread 'or unthread it about the spindle body 42. The hammer nut 52 may be disengaged from the spindle body 42 to allow the inner drill pipe 64 to be withdrawn from the outer drill pipe 65 as will be hereinafter described.

The lower end of the spindle body 42 is threadedly connected to the outer drill pipe 65 by means of an adapter coupling 66.

The outer drill pipe' 65, as shown", is'cornprised ofa unitary tubular member. It will'be understood, however, that it could be made up of several sections of pipe joined by suitable couplings or threads. Ordinarily the bore holes drilled in quarrying or geophysical exploration are relatively shallow so that the outer drill pipe can be made in one piece, but in the event holes are to be drilled to such depth as to require several joints of pipe, such can be provided.

An annular cutting bit 67" is threadedl engaged to the lower end of the outer drill pipe 65, said bit 6'7 having annularly spaced cutting teeth 63 formed on the lower side thereof. The bit'67 has a circular passage 69 therethrough of sufficient diameter to permit the passage of the inner bit there'through. The outer bit 67 may be engaged with the lower end of the outer drill pipe 65, after the drill pipe has been passed through the rotary table 18, and of course may be replaced when desired.

The inner drill pipe, indicated generally by the numeral 64, passes through the outer driil pipe 65 and as shown is made up of a plurality of sections of tubular members 70 which are threadedly joined together by ineans of subs 71. The upper section of the inner drill pipe 64 is threadedly connectedto the lower end of the inner adapter 56 and is supported thereby when the adapter 56 is keyed to, and suspended in, the spindle body 42, as shown in FIGURE II.

The inner drill pipe 64 has an inner drill bit 74 threadedly engaged to the lowermost section 70 by means of an adapter sub 72.

The inner drill pipe 64 is of such length as to permit the lower end of the inner bit 74 to slightly extend beyond the lower end of the outer bit 67, when the inner adapter 56 is disposed in, and keyed to, the spindle body 42. The inner bit 74 and outer bit 67, when so disposed, in effect, form one drill bit for penetrating the earth.

The inner bit 74 has a plurality of cutting teeth 76 spaced about the lower face thereof, and between the cutting teeth 76 are flow orifices 75 through which circulating fluid may pass when circulated downwardly through the inner drill pipe 64. Such fluid passes downwardly through the inner drill pipe 64 and outwardly through the orifices 75 and upwardly through the annular space between the outer drill pipe 65 and the well bore 15 to the surface, in order to provide circulation for carrying away the cuttings of the bits, and for the purpose of providing coolant for the bits.

Suitable mechanism is provided for keying the drill stem 14 to the rotary table 18 for rotating the drill stem. Such keying mechanism may take different forms, but the specific form disclosed herein includes a substantially square-shaped master bushing 79, having straight inner and outer sides, which may be inserted in a mating receptacle (not shown) in the rotary table 18, whereby the rotation of the rotary table. will rotate the bushing 79.

The master bushing 79 has an annular flange 80 thereon which comes into supporting engagement with the top of the rotary table 18 when the bushing 79-is inserted therein,

An inner bushing 81, having fiat outer sides and a circular inner side, is arranged to be inserted in, and gome into mating engagement with, the master bushing The inner bushing 81 has an annular flange 82 thereon arranged to rest upon the upper end of the master bushing 79 to support same with reference thereto.

An annular handle 83, which is secured to flange 82 on the inner bushing 81 by means of spaced arms 84, is provided for the purpose of allowing handling and manipulation of the bushing 31 for removing same from the master bushing 79 or inserting it therein.

A plurality of spaced longitudinal slots 85 are formed on the inner side of the inner bushing 81, and a squaresided plate 86 is secured to the lower endof the inner bushing 81 by means of a suitable weld, said plate 86 overlapping the lower ends of the slots 85 to form a support for the drive pins 88.

A plurality of spaced longitudinal channels 87, which are complementary to the slots 85, are formed on the outer side of the outer drill pipe 65. The channel 87 extend substantially the entire length of the outer drill pipe 65. The drive pins 88 may be inserted in the complementary channels 87 and slots 85 to thereby key the bushing 81 to the drill pipe 65.

In assemblying the drive mechanism with relation to the outer drill pipe 65, the inner bushing 81 is inserted in the outer bushing 7? and the inner bushing is placed about the outer drill pipe 65. The slots 85 and channels 87 are brought into alignment and the drive pins 88 are inserted in the coinciding slots and channels. After the drive pins are so inserted a retaining ring 89 is passed about the drill pipe 65 and disengagably attached to the upper end of the inner bushing 81 by means of a cap screw 9%). The drive pins 88 may be quickly changed by-removing the retaining ring 89, thus permitting the drive pins to be withdrawn.

6 It will thus be seen that the inner bushing 81 is slidably keyed to the outer drill pipe 65 by means of drive pins 88 which may slide longitudinally in the channels 87. As described above, the inner drill pipe 64 and outer drill pipe 65 are keyed together for rotation in unison by the keys 6t? and key channels 61, and since the outer drill pipe 65 is keyed to the rotary table 18 by the drive as-.

sembly just described, the rotation of the rotary table will rotate the drill stem, made up of the inner tubular member 64 and the outer tubular member 65.

The outer drill pipe 65 is permitted to slide downnumber of sections 70 to provide sufficient length to.

extend through the outer drill pipe 65, and the inner adapted 56 and swivel 28 are attached to the upper end' thereof. The inner drill pipe 64 is run into the outer drill pipe until the inner adapter 56 is suspended in the spindle body 42, with keys 60 and key channels 61 in mating.

relationship. The outer drill pipe may be suspended to the mast 10 by means of the cable 29 attached to the bail 26.

The bearing spindle assembly 27 and the drive mechanism 17 are attached to the outer drill pipe in themanner" hereinbefore described.

The master drive bushing 79 isinserted in the'rotary table in the manner described, and the

bits

67 and 74 are attached to the lower ends of the concentric drill pipes.v

After the device is thus assembled, as shown in FIGS.

II, III and IV, the circulating hose 38 is connected and it is suspended to the mast 10 by the cable 29, as shown, The rotary table may then be rotated to there-..

in FIG. I. by rotate the assembled drill stem to cause the drill bits to dn'll a hole into the earth. As the hole is drilled the drill stem 14 slides downwardly through the rotary table.

After the hole has been drilled to a desired depth, the hammer nut 62 may be disengaged from the spindle body 42, the cable 34 may be attached to the eye 37 on the rotary swivel 28 and the inner drill pipe 64 may be drawn upwardly out of the outer drill pipe 65, thus leav-' ing the outer drill pipe 65 in the hole.

Before withdrawing the inner drill pipe from the outer drill pipe the hose 38 should be disconnected from the rotary swivel 28.

An explosive charge may then be lowered to the bottom of the hole through the outer drill pipe 65 and throughthe opening 69 in the lower end of the bit 67. Such explosive charge may be lowered into the pipe 65 onelectric leads through which the charge may later be detonated from the surface.

After so placing the explosive charge in the hole, the

outer pipe 65 may then be withdrawn from the hole on the cable 29. Before withdrawing the outer pipe from the hole the end of the inner pipe 64 is placed in the top of the outer pipe 65 and the two pipes are telescoped together as the outer pipe is pulled out of the hole.

The explosive charge in the hole may then be deto-- nated. 7

After the inner and outer drill pipes have been thus 'telescoped and again brought into concentric relationship, the hammer nut 62 is again engaged with the spindle body 42 to thereby join the pipe strings together.

The drilling device may then be transported to another location for the drilling of another hole.

In FIGURES IX-XI is shown a modified structure for detachably connecting the rotating spindle and the adapter head against relative rotational and longitudinal movement, whereby the inner drill pipe and the outer drill pipe may be detachably connected for rotation together.

Referring to the drawings of such modified form, the

numeral 91 generally indicates the modified adapter head which includes a tubular body 92 having an integral upwardly extending neck 93 thereon, on which neck is formed male threads 94 for threaded attachment to the rotatable tubular part 55 of the rotary swivel 28.

The tubular body 92 has male threads 935 formed on the lower end thereof which may be threadedly attached to the sub 96. The sub 96 is secured to a section of drill pipe '97 by means of a weld 97a. The section of pipe 97, which constitutes a section of the inner drill pipe, has provided on its other end a sub (not shown) like that shown at 96, which may be threadedly attached to another section of the inner drill pipe.

An annular shoulder 98 is secured to the tubular body 92 by means of welds 99 and 99a.

An annular skirt 1% is secured to the shoulder 98 by means of a weld 101.

The skirt 1130 has a plurality of J-slots 102 formed therein, each J-slot 102 including a horizontal portion 103 communicating with a vertical opening 104 which is arranged to receive the lock pins 115, hereinafter described.

The tubular spindle body 1105 includes an integral bearing retainer skirt 1%. The upper bearing 1%! and the lower bearing 1% are spaced apart and retained in place against outward movement by a bearing retainer ring 169, the upper end of which extends under the skirt 1%. A pair of cars 11% are formed on the bearing retainer ring 109, to which the bail 111 is pivotally attached on the bearings 11 1a.

The bearing assembly is held together by means of -a retainer nut 112 threadedly engaged to the spindle body 1115. The bearing retainer nut is secured against rotation by a set screw 113, after it has been rotated in place. A seal 118 is disposed between the bearing retainer nut 112 and the retainer ring 109 to prevent the escape of lubrication from the bearing assembly.

A lock ring 1 14 is secured to the spindle body 105 by means of a weld 114a.

A plurality of lock pins 115, there being one for each of the J-slots 102, are secured to the lock ring 114 by means of welds 116, such lock pins being extended through passages in the wall of the lock ring 114 and fixedly attached therein by the welds 116. The lock pins 115 extend outwardly of the lock ring 114 and are so arranged about the periphery thereof that they may be placed in alignment with the vertical openings 194 of the J-slots lit-2.

A seal ring 118 is provided between the shoulder 98 and the lock ring 114, said seal ring being held in place by the screws 119.

To attach the modified adapter head 91 hereinbefore described, to the modified spindle body 195, the skirt or depending portion 109 is positioned over the lock ring 114, and the vertical openings 104- of the J-slots 1632 are brought into alignment with the lock pins 115, so that the lock pins 115 may be passed through the vertical passages 1M and be brought into alignment with the horizontal portion 133 of the J-slots 1&2 when the skirt 1% is positioned in overlapping relationship to the lock ring 114. The adapter head 91 is then rotated counter clockwise with relation to the spindle body 165, thereby causing the lock pins 115 to move laterally in the hori: zontal portions 1% of the J-slots 102. It will be seen that the inner drill pipe and outer drill pipe are thus detachably secured together against relative longitudinal movement and that when the spindle body 105 is rotated clockwise by means of the drive mechanism hereinbefore described, the lock pins 115, by virtue'of their engagement with the end of the horizontal portions 103 of the J-slots 102, cause the rotation of the adapter head 91 and the inner drill pipe attached thereto. The pins 115 and the J-slots 1612 provide a modified form of slidably keyed connection between the adapter head 91 and the rotating spindle 105, and thereby provides a detachable connection between the telescoping inner and outer' drill pipes so that the drill pipes may be sepa-. Such bayonet type conrately withdrawn from the hole. nection provides means to detachably secure the inner and outer drill pipe together for preventing relative rotation therebetween and means for preventing relative longitudinal movement thereb etween while drilling.

The adapter head 91, and the rotating spindle 155, may be easily separated by simply rotating the skirt 1% in a clockwise direction with relation to the lock ring 114 so as to bring the lock pins in alignment with the vertical openings 164, so that the adapter headand the rotating spindle may be separated by relative longitudinal movement.

The procedure for drilling and the assembly of the inner and outer drill pipes and the placing of the explosives in the hole and detonating same is the same asv that described with relation to the first form herein described.

It will be seen that we have provideda drilling device for the purposes herein described, wherein there is provided an inner drill pipe which may be withdrawn from an outer drill pipe for the purpose of leaving a casing in the hole while explosive charges or otherdevices are lowered into the hole, thereby facilitating the placing of. such explosive charges into the hole and eliminating the possibility of the hole becoming obstructed by loose material prior to lowering the explosive charge therein. Such a drilling device results in a great savings in time and expense in carrying out quarrying or geophysical exploration.

It will be understood that this invention would have general application in any drilling operation where it is desired to leave a casing in the hole after it has been drilled, thus eliminating the necessity of running and setting a separate casing.

It will be apparent that other and further forms of my invention, in addition to that disclosed herein, may be devised without departing from the spirit and scope of the appended claims.

I claim:

1. In a drilling device, an outer drill pipe; a rotatable spindle attached to the upper end of the outer drill pipe; an inner drill pipe telescopically disposed in the outer drill pipe; a hollow head attached to the upper end of the inner drill pipe and being positioned in the spindle; and key and keyway means arranged between the spindle and the head whereby they may be rotated together; and means to secure the spindle and head together against relative longitudinal movement.

2. in a drilling device, an outer drill pipe; a rotatable spindle attached to the upper end of the outer drill pipe; an inner drill pipe telescopically disposed in the outer drill pipe; a hollow head attached to the upper end of the inner drill pipe, and being positioned in the spindle; longitudinally slidable key and keyway means arranged between the spindle and the head whereby they may be rotated together; means to secure to spindle and head together against relative longitudinal movement; and means to rotate the outer drill pipe.

3. In a drilling device, an outer drill pipe; a rotatable spindle attached to the upper end of the outer drill pipe; an inner drill pipe telescopically disposed in the outer drill pipe; a hollow head attached to the upper end of the inner drill pipe and being positioned in the spindle; longitudinally slidable key and keyway means arranged between the spindle and the head whereby they maybe rotated together; means to rotate the outer drill pipe; and means for securing the spindle and the head against relative longitudinal movement, said means being releasable to permit the inner drill pipe to be Withdrawn from the outer drill pipe.

4. In a drilling device, an outer drill pipe; a rotatable spindle attached to the upper end of the outer drill pipe; an inner drill pipe telescopically disposed in the outer drill pipe; a hollow head attached to the upper end of the inner drill pipe, and being positioned in the spindle; longitudinally slidable key and keyway means arranged between the spindle and the head; means to secure the spindle and head together against relative longitudinal movement; and a fluid circulating head attached in communication with the hollow head.

5. In a drilling device; an outer drill pipe; a rotatable spindle attached to the upper end of the outer drill pipe; an inner drill pipe telescopically disposed in the outer drill pipe; a hollow head attached to the upper end of the inner drill pipe, and being positioned in the spindle; the said hollow head being slidably keyed to the spindle for rotation therewith; and means to secure the spindle and head together against relative longitudinal movement.

6. In a drilling device, an outer drill pipe, a rotatable spindle attached to the upper end of the outer drill pipe; an inner drill pipe telescopically arranged within the outer drill pipe; a hollow head attached to the upper end of the inner drill pipe and being positioned in the spindle; means disengageably attaching the spindle to the head to prevent relative rotation therebetween; and means to secure the spindle and head together against relative longtudinal movement.

7. In a drilling device, an outer drill pipe; a rotatable spindle attached to the upper end of the outer drill pipe; an inner drill pipe telescopically arranged within the outer drill pipe; a hollow head attached to the upper end of the inner drill pipe and being positioned in the spindle; longitudinally slidably related means on the head and in the spindle to prevent relative rotation therebetween; and disengageably attached means between the head and the spindle to prevent longitudinal movement therebetween.

8. The combination called for in claim 7 wherein the longitudinally, slidably related means consists of key slots on the inner side of the spindle and complementary keys formed on the outer surface of the head.

9. The combination called for in claim 7 wherein the disengageably attached means comprises a nut threadedly engaged about the spindle and having a part engaged with the supper side of the head.

10. In a drilling device, an outer drill pipe, a rotatable spindle attached to the upper end of the outer drill pipe; an inner drill pipe telscopically arranged within the outer drill pipe; a hollow head attached to the upper end of the inner drill pipe and being positioned in the spindle; and means disengageably attaching the spindle to the head to prevent relative rotation and longitudinal movement therebetween.

11. In a drilling device; an outer drill pipe; a rotatable spindle attached to the upper end of the outer drill pipe;

an inner drill pipe telescopically arranged within the outer drill pipe; a hollow head attached to the upper end of the inner drill pipe and being positioned in the spindle; and means disengageably attaching the spindle to the head, said means including a portion depending from the head overlapping the upper end of the spindle; and means disengageably attaching the overlapping portion to the spindle.

12. The combination called for in claim 11 wherein the means disengageably attaching the overlapping portion to the spindle consists of a bayonet joint connection between such members.

13. The combination called for in claim 11 wherein the means disengageably attaching the overlapping portion to the spindle comprises at least one J-slot in the overlapping portion, and a pin extending outwardly of the spindle arranged to engage the J-slot.

14. In a drilling device, an outer drill pipe; a rotatable spindle attached to the upper end of the outer drill pipe; an inner drill pipe telescopically arranged within the outer drill pipe; a hollow head attached to the upper end of the inner drill pipe and being positioned in the spindle; an annular skirt depending from the head arranged to overlap the upper end of the spindle; a plurality of J-slots arranged in the wall of the skirt; and a plurality of lock pins arranged about the spindle in position to engage in the J-slots to thereby disengageably attach the head to the spindle.

15. The combination called for in claim 10 wherein the means disengageably attaching the spindle to the head consists of a bayonet joint connection between such members.

16. In a drilling device, an outer drill pipe; a rotatable spindle attached to the upper end of the outer drill pipe; an inner drill pipe telescopically arranged Within the outer drill pipe; a hollow head attached to the upper end of the inner drill pipe and being positioned in the spindle; an annular skirt depending from the head arranged to overlap the upper end of the spindle; and means defining a bayonet joint connection between said skirt and said spindle to thereby disengageably attach the head to the spindle.

References (Iited in the file of this patent UNITED STATES PATENTS 1,908,227 Dodds May 9, 1933 2,684,229 Bergstrom July 20, 1954 2,784,949 Peck Mar. 12, 1957 FOREIGN PATENTS 1,042,438 France June 3, 1953