US3105560A - Weight controlled vibratory drilling device - Google Patents

Description

Oct. 1, 1963 J. AA. zuBLlN WEIGHT coN'rRoLLED VIBRAToRy DRILLING DEVICE Filed Jan. 4, 1960 3 Sheets-Sheet 1 IN V EN TOR.

Bz (QQ/,caw

Oct. 1, 1963 J. A. zUBLlN WEIGHT coNTRoLLED VIBRATORY DRILLING DEVICE Filed Jan. 4, 1960 3 Sheets-Sheet 2 f fd d/// 4. ZUB /A/ y INVENTOR.

Oct. 1, 1963 J. A. zUBLlN WEIGHT coNTRoLLED vIBRA'roRY DRILLING DEvcE Filed Jan. 4, 1960 n 5 Sheets-Sheet 3 INVENTOR.

United States Patent C) 3,165,569 WElGi-i'i CQNTRLLED VIBRATRY BEILLENG DEWCE lohn A. Zublin, Los Angeles, Calif.; Marie N. Znblin,

execntrix ot said .lohn A. Zuhlin, deceased, assigner of one-hallB to Maria N. Znblin and one-half to C.

William Zublin Filed lan. 4, 1960, Ser. No. 334 Claims. (Cl. 1'75-56) The present invention relates to vibratory drilling devices and more particularly to an 'nnproved drilling device which takes advantage of the substantial and signicant energy potential of the drilling fluids ordinarily circulated through a drill string in the drilling of oil and gas wells and the like.

lt is the conventional practice in the case of drilling oil and gas wells, and more particularly in the drilling of oil and gas wells by what is commonly called the rotary drilling method, to circulate down through the drill string or drill pipe so-called drilling uids which serve to ilush to the earths surface cuttings occasioned by penetration of the bit as the bore hole progresses. Obviously, the drilling fluid so circulated has substantial energy potential which in conventional rotary drilling methods is not utilized in the advancement of the drill bit.

Among the primary objectives of the present invention is the provision of a vibratory drilling device which avails of the energy potential oi the drilling fluid to eiect or assist in the drilling operation.

ln my Patent No. 2,743,083 dated April 24, 1956, for Apparatus to impart Vibrating Motion to a Rotary Drill Bit, there is disclosed an apparatus for imparting vibrating motion to a rotating drill bit including a rotatable uid ilow interrupter for intermittently interrupting the flow of drilling lluid through the string of drill pipe to the drill bit. This interrupter is driven by a portion of the drilling fluid owing through the drill string, and as a result of the interruption to the ilow of drilling iiuid high frequency vibrations are created so as to vibrate the drill bit during the drilling operation, thus to advance the bit into the earth formation.

ln the drilling of oil and gas wells, particularly at substantial depths, there is a substantial kinetic energy available by reason of the circulation of drilling fluid, and in asmuch as the kinetic energy or inertia force available is proportional to the velocity of the circulating drilling lluid the kinetic energy may be availed of by the partial and intermittent interruption of the fluid flow without adversely curtailing or diminishing circulation to the surface through the bore hole outside the drill string. However, unless means be provided for varying the extent to which the circulation of iluid is interrupted, then the only practical way to vary the application of available kinetic energy on the drill bit is to vary lthe interruption cycle time by varying the velocity of the circulating fluid since the mass of the drilling iiuid is more particularly determined by the variable well conditions, as for example, the down hole pressure conditions which may be encountered and which must be overcome by the drilling fluid in order to prevent the well from blowing out. On the other hand, the velocity of the drilling fluid cannot be varied except within the practical limits dictated by the type of formation being drilled through, since the velocity or" the iluid returning to the surface must be suicient to carry specific cuttings to the surface without permitting such cuttings to fall out or settle to the bottom of the hole.

Accordingly, the present invention contemplates as an object the provision of a vibratory drilling device having means operated by the circulation of drilling fluid through l-SM Patented ct. l, 1963 the device for intermittently partially interrupting the ilow of drilling iiuid through the device so as to impose on the drill bit beneath the device significant uid inertia forces causing high frequency vibrations of the drill bit to eiect penetration of the bit through the earth formation, wherein the device is so constructed as to vary the extent or degree to which the circulation is interrupted, as a function of the weight of the drill string or drill pipe above the drilling device.

ln the drilling of oil and gas wells as is well known to those skilled in the art, it is the practice to support the drill stem at the earths surface so that the string of pipe is in tension down to a predetermined point known as the eutral point, below which point the drill string is in compression. Thus, from the neutral point in the drill string to the present vibrating device, the weight of the drill string will be imposed on the device, and as more or less of the drill string is supported in tension the weight on the device will be proportionately varied. Therefore, it is another object of the invention to provide a drilling device of the type aforementioned having a iiuid flow interrupter providing a ow passage which is varied so as to vary the extent or degree to which the circulation of drilling fluid through the device is interrupted, upon variation in the Weight of the drill string which is imposed upon the device. In this connection, it is contemplated that on the order of of the circulation of drilling fluid through the interrupter of the invention may be interrupted per interruption cycle while the remainder of the fluid is free to circulate so as to carry formation cuttings to the surface. The percentage or degree of circulation interruption may be decreased by reducing the weight of the drill string which is imposed upon the drilling device so that less of the circulation is interrupted with resultant reduction in the inertia force or kinetic energy employed to effect vibration of the drilling device and thus to elect advancement of the drilling bit.

Yet another object of the invention is to provide a drilling device which is extremely rugged yet easy to manufacture and install in a string of drill pipe.

Gther objects and advantages of the invention will be hereinafter described or will become apparent to those skilled in the art, and the novel features of the invention will be defined in the appended claims.

Referring to the drawings:

FiG. l is a longitudinal sectional view through a vibratory drilling device made in accordance with the invention and disposed in a well drilling string with the in terrupter parts shown in a position for effecting a minimum interruption to the circulation of drilling iiuid through the device during each interruptor cycle;

FIG. 2 is a view corresponding to FIG. l but showing the interrupter parts in condition for effecting a maximum interruption to the flow of -circulation of drilling iiuid through the device during eac-h interrupter cycle;

FlG. 3 is an enlarged vfragmentary detail view in longitudinal section more particularly showing the interrupter device with the parts in position for interrupting the iiow of fluid therethrough;

FIG. 4 is a detail view in perspective `of the turbine drive means for the interrupter with certain of the parts broken away and shown in section;

FIG. 5 is a transverse sectional view `on a slightly enlarged scale as taken on the line 5-5 of FIG. l;

FIG. 6 is a transverse sectional view on a slightly enlarged scale as taken on the line 6 6 of FIG. l;

FIG. 7 isA a transverse sectional View o-n a slightly enlarged .scale as taken on the line 7-7 of FIG. 1;

FIG. 8 is a transverse sectional view on a slightly enlarged scale as taken on the line 8-8 of FIG. l;

FIG. 9 is a transverse sectional View on a slightly enlarged. scale as taken on the line 9 9 of FIG. l;

HG. l is a fragmentary view in section of a modication of the interrupter device; and

FIG. ll is a transverse sectional View as taken on the lil e Ill-ll of FIG. l0.

Like reference characters in the several views of the drawings and in the following description designate corresponding parts.

Referring to FIG. l, the drilling device of the invention is generally designated at D and is installed in a drilling string between a conventional bit B and the lower end of a drill string S which may be constituted by a so-called drill collar. A drill collar, as well recognized in the art, is a rigid, hollow, -relatively heavy length of pipe adapted to provide a rigid support for a drill bit. VAny number of drill collars may be employed above the device in order to assure directional control of the hole being drilled and if desired to aord additional weight to be imposed upon the drilling device for a purpose which will hereinafter be more particularly described. In addition, it desired, a further drill collar or bit sub may be installed between the bit B and the device D.

The device at its upper end includes a coupling l having an externally threaded pin 2 engageable in the internally threaded box 3 at the lower end of the drill string S. At its lowered end the connector l has an externally threaded pin 3 adapted to be threadedly received in the internally threaded upper end 4- of a tubular housing 5. At the lower end of the housing 5 there is appropriately provided or threadedly attached an externally threaded abutment sleeve 6 composed of hard material capable of withstanding heavy loads without adverse elect. Reciprocably disposed in the sleeve 6 and keyed thereto so as to preclude relative rotation as by a plurality or inter-tting splines or ribs and grooves as indicated at '7 is the neck S of a connector sub 9 having a shoulder lll opposed to the lower extremity of the sleeve o for abutting engagement therewith to limit movement of the ldevice D downwardly relative to the connector sub 9. ln the illustrative embodiment the connector sub 9 is provided with an internally threaded box lll adapted for connection yto the stem l2 of the bit B.

Movement oi' the connector sub 9 downwardly relative to the housing 5 is limited by a coupling i3 threadedlyV connected to lthe neck 8 of connector sub 9 as by a threaded connection llland having a shoulder l5 engageable with the inner end yof the sleeve 6. rThus, it -is apparent that the connector sub 9 and the housing 5 are interconnected for relative reciprocation, but the spline connections 7 preclude relative rotation therebetween.

Threadedly connected to the connector 13 as at 16 lis an interruptor stator 13 having an upstanding hollow section 19 and a pair of gradually tapered flow passages 29 therethrough at the opposite sides of an upstanding pin 2l supported in the body of the interrupter stator by -a pair of opposed webs 22, as best seen in FIG. 8.

Y interposed between the `connector l and the interruptor stator 1S is a packing ring 23 which prevents the passage of drilling fluids between the interruptor stator and the housing 5. Thus, it becomes apparent that the interruptor stator by virtue of the provision of 4the sealing ring 23 constitutes a piston reciprocable in the housing 5, and the neck S of connector sub 9 constitutes a rod connecting the piston to the bit B. The piston is ported, however, by means of the passageways Ztl which lead to a tapered passage 24 through the connector 13 and thence into a bore 25' Vthrough connector sub 9 and through a bore 26 in the neck 12 of Ibit B from whence iluidpasses into the wellbore generally designated W soV as to pass upwardly in the well bore outside the device and then to` the top of the well.

A rotor assembly is generally designatedV at 27 and includes an interrupter rotor `section 28 having `a downwardly extending portion 29 disposed in the upstanding annular portion 19 of interruptor stator 18. 'Ihe interrupter rotor Z8 has a downwardly tapering passage 3d therethrough partially closed at its lower end by arcuate segments 3l (see FIG. 7) disposed in diametrically opposed relation and having arcuate inner peripheries 32 disposed about the upstanding interruptor stator pin 2l. These arcuate rotor segments Si constitute valves which will upon rotation of the linterruptor rotor '2S partially interrupt the ow of drilling tluid through passages 2li in inte-rrupter stator i8, and between the arcuate segments 3l are flow vpassages 33 which when aligned with flow passsages 2G in the interrupter stator 18 enable a free flow of uid through the interrupter assembly for drilling fluids circulating through the device. The rotor assembly 27 above the interrupter rotor 23 has an interruptor drive turbine rotor 34 (see FIG. 4) comprising an annular body 35 having a hub 36 and `a plurality of circumferentially :spaced radiating ns 37. Preferably, the turbine rotor 34 is welded as at 38 to the interruptor rotor 2S, but of course, other suitable assembly means may be availed of.

/leans are provided for rotatably supporting the rotor assembly 27 in the housing 5. ln the illustrative ernbodiment such means are composed of a series or" bearing balls. The interruptor rotor 2S is provided with an outer peripheral annular ball race 25' and the housing 5 is provided `with an opposing ball race 5 in which is a plurality of bearing balls 4l?. These balls d@ are supplied to the opposing races 5 and 23 through an opening S" in the housing 5 which is closed by a plug 5'" after insertion of a suitable number of the balls di?. Similarly, a pu-rality of balls il and 4Z are disposed in vertically spaced races 5a, 5b and 35a and 3517 in the housing 5 and the turbine rotor Sil, respectively, the balls il being retained in the races by plug 5c and the balls l2 being retained in their races by a plug 5d.

Disposed in the housing S above the rotor assembly 27 and more particularly in close proximity to the turbine rotor 3i!- is a turbine stator 4S (see FIG. 4) composed of an annular body 46, a central hub i7 and radiating iins or vanes 48 spaced circumferentially and extending radially between the hub 4iand the body d6. The turbine stator 45 is suitably secured in the body 5 as by plug welds at 46 or, of course, may be otherwise secured in place.

Leading through the connector l is a fluid passage 49 which carries drilling duid from the drill string S to the turbine stator 45. It will be noted that the turbine stator iins or vanos 4S are angolari-J disposed so as to impart a circumferential component of motion to drilling uid passing therebetween, which fluid impinges upon the vanes 37 of the rotor 34 so as to drive the rotor assembly 27 with consequent rotation of the interrupter rotor 2S. Thus, during circulation of drilling iluid through the device the rotor assembly 27 will continuously revolve and luid will pass downwardly through the segmental passages 33 lying between segmental webs 3l and thence through openings 2i? in interruptor stator l.

ln the operation of the device it will be run into the well on the drill string S with the parts in the condition shown in FIG. l, shoulder l@ of connector sub 9 being spaced downwardly from sleeve 6, and with a resultant maximum spacing and free flow area between interr-upter rotor 28 and interruptor stator i8. lVhen the bit B is landed at the bottomof the well W as'shown in FIG. 2, the weight of the drill string above the device will cause the housing to move ydownwardly relative to connector sub stem 8 until sleeve 6 abuts with shoulder lll at which time there will be a minimum axial spacing between interruptor rotor 28 and internupter stator 18 as shown in FIG. 2.

Accordingly, circulation of drilling luid through the device will cause rotation of the turbine yrotor 35, thus causing interruptor rotor segments 3l to pass over ports or passageways 253 through interrupter stator 18 to partially interrupt the flow of drilling fluid through the device with resultant water hammer effect proportional to the mass and velocity of the drilling fluid. The extent or degree to which circulation of uid will not be interrupted is governed by the axial clearance between the interrupter rotor 2S and the stator 1S. The kinetic energy of drilling iiuid interrupted by Ithe interrupter device will, of course, be irnposed upon the piston constituted by the interrupter stator as referred to above to force the bit into the formation with powerful rapid shocks of a frequency determined by the velocity of the drilling fluid acting on the interrupter drive turbine and of a magnitude proportional to the velocity of the uid and its mass, under the control of the driller or operator of the drill string at the surface, who can by conventional methods control the portion of the weigh-t of the driil string which is imposed upon the device D and more particularly lwhich is imposed upon the housing 5 so as to hold the interrupter rotor 28 in a desired relation to the stator 1S to vary the axial spacing therebetween.

lt should be noted that the interrupter rotor 2S is substantially convex on its lower surface and is opposed by a complemental concave surface of the interrupter stator 18. The fluid passing between these opposed concave and convex surfaces when rotor elements 31 are in overlying relation to stator passages 2G travels in an arcuate downward path. Therefore, -while fluid velocity through these parts is at its peak when the ow is at a minimum, the resultant duid erosion is signicantly reduced. In addition, the stator pin 21 affords a blockage against the flow of huid in a short direct path from rotor passages Sii to stator passages 29 when rotor elements 3i partially block stator passages 2i), .the fluid being forced to flow circumferentially about the pin 2l. to stator passages 2t) which, as aforementioned, taper downwardly. By reason of this structure, sharp changes in the direction of fluid How are minimized, the life of the parts is enhanced since they are not subjected to the otherwise severe wearing eifects of high velocity abrasive drilling fluid.

It will be apparent that as the flow of iiuid is interrupted through the device, the hydraulic forces derived from the circulating iiuid, while acting `downwardly on the piston constituted by the interrupter stator 18, will also act upwarly on the drill string. 'l'he extent that this upward component 4of force on the drill string is effective :to enable actual separation of the interrupter rotor and interrupter stator will be dependent upon the weight of the drill string which is imposed upon the device D. Therefore, under the control of the driller significant and eective successive intermittent 'water hammer effects will be created for vibrating the bit B or imposing intermittent iiuid inertia forces thereon to drive the bit into the formation.

Such progression of the bit into the formation, it will be understood, is not dependent upon rotation of the drill string as in the rotary drilling method, but is independent of such rotation. However, if desired, the invention may be availed of while rotating the drill string to effect progression of the bit in accordance with the conventional rotary drilling method and augmenting such a progression by the successive water hammer effects created by virtue of the present invention.

Referring to FIG. l0, there is shown a modification of the invention in which a spacer 100 ds interposed between the sleeve 6 and the interrupter stator i8 so -as to prevent relative longitudinal movement of the bit relative to the housing 5 of the drilling device. Under these circumstances, intermittent interruptions in the flow of drilling uid caused by the interrupter previously described will create high frequency shock waves which will be transmitted to the entire string of drill pipe and drill collars which is virtually an elastic string, thus causing high frequency vibrations of the entire drilling string mass which 5 will create bit vibrations of increased frequency. The high frequency vibration yof the entire idrill string coupled with the lintermittent water hammer eiect created by the interruptor will further enhance the penetration rate of the bit through the formation.

While -a conventional bit -B has been herein shown, including toothed roller cones R, it will be understood that any conventional form of bit may be employed without departing .from the spirit of the invention.

Moreover, while specic structural `details have been shown `and described, it should be understood that changes and alterations may be resorted to without departing from the spirit yof the invention as defined in the appended claims.

'I claim:

1. Apparatus for imparting vibrating motion -to ia drill bit, comprising: Aa housing adapted to be disposed in a string of drill pipe above the drill bit; means in said housing for intermittently interrupting the iiow of drilling iiuid therethrough including van .interrupter stator and an interrupter rotor; said interrupter parts being supported in said housing for relative movement one towards the other; and a connector ldevice connected to one of said interrupter parts for axial movement therewith land projecting from said housing lfor connection to the drill bit in the drill string; said housing and said connector device having coengaged means axially movable relative to one another for transmitting torque Ito the drill bit and for allowing movement of said interrupter parts one toward the other.

2. Apparatus for imparting vibrating motion to la drill bit, comprising: a housing adapted to be disposed in a string of drill pipe above the drill bit; means in said housing yfor intermittently interiupting the flow of drilling fluid therethrough including an interrupter stator and an interruptor rotor; said interrupter parts being suppor-ted in said housing for relative movement one towards the other; and a connector device connected to one of said interruptor parts for axial movement therewith land projecting from said housing for connection to the drill bit in the drill stiing; said connector and said housing having opposing shoulders engageable with Ione another upon movement of said interrupter parts one towards the other; said connector and said housing also having coengaged means axially movable relative to one another for transmitting torque to the ldrill bit and for allowing movement of said interruptor part-s one toward the other.

3. Well drilling apparatus, comprising: a string lof drill pipe; a drill bit at the lower end of said ydrill pipe; a vibratory device interposed in said drill pipe above said bit; said device comprising an elongated housing having a connector at one end; a connector reciprocable in said housing -at the other end thereof and projecting therefrom; one of said connectors being connected to said drill pipe and the other of said connectors being connected to said bit; fluid ow interruptor means in said housing including a rotary part and a non-rotary part; one of said parts being connected to said reciprocable connector and shift-able axially :in said housing relative to the other part for varying the extent of iiuid interruption of said interrupter means; means for rotating said rotary interrupter part upon circulation of drilling uid through the device; and coengaged means on said reciprocable connector and said housing for transmitting torque to said bit.

4. Apparatus as deiined in claim 3, wherein `the means for rotating said rotary interrupter part comprises `a turbine stator carried by said housing and 'a turbine rotor carried by said rotary interrupter part.

5. Apparatus as defined in claim 3, wherein said interrupter parts each have arcuate openings land webs.

l6. Apparatus as defined in claim 3, including la spacer blocking said reciprocable connector `against movement in said housing.

7. Apparatus as defined in claim 3, wherein said axially shitable `interi-tiptel' part is provided with means sealingly engaging said housing.

8. A well drilling apparatus for a string of drill pipe having a drill bit at the lower end `of said string, comprising: yan elongated housing `conneetable at one end in said pipe string; a connector reciprocable in the other end of said housing and projecting beyond the housing for connection in said string; a drilling fluid ow passage through said housing and said connector; a fluid flow interrupter stator on said connector and reciprocable in said housing; ya iluid ow interrupter rotor rotatably mounted in said housing; said stator and rotor having iiow passages cyclically aligned with one another upon rotation of said rotor; and fluid ilow responsive means in said housing for driving said rotor. l

9. A well drilling `apparatus for a string of drill pipe having a drill bit at the lower end of said string, comprising: yan elongated housing `connectable at one end in said pipe string; a connector reciprocable in the other end of said housing and eonnectable in said string; a drilling iluid llow passage through said housing and said connector; a lluid ow interrupter stator yon said connector and reciprocahle in said housing; -a l'luid flow interrupter rotor rotatably mounted in said housing; said stator and rotor having tiow passages cyclically aligned with one another upon rotation of said rotor; Ia drilling lluid ow esponsive turbine rotor connected to said interrupter rotor; and a turbine stator in said housing adjacent to said turbine rotor.

10. A well drilling apparatus for a string of drill pipe having a drill bit at the lower end of said string, comprising: an elongated housing connectable at one end in said pipe string; a connector reciprocable in the other end of said housing and connectable in said string; a drilling fluid flow passage through said housing and said connector; a lluid low interruptor stator on said connector and reciprocable in said housing; sealing means between said stator and said housing; a fluid liow interrupter rotor rotatably mounted in said housing; said stator and rotor having liow passages eyclically aligned with one another upon rotation of said rotor; and fluid flow responsive means in said housing for driving said rotor.

1l. A well drilling apparatus for a string of drill pipe having a drill bit at the lower end of said string, comprising: an elongated housing connectable at one end in said pipe string; a connector reciprocable in the other end of said housing and conneetable in said string; a drilling fluid llow passage through said housing and said connector; a liuid flow interrupter stator on said .connector and reciprocable in said housing; a fluid flow interrupter rotor rotatably mounted in said housing; said stator and rotor having llow passages cyclically aligned with one another upon rotation of said rotor; said housing and said conynector having opposed portions engageable for limiting reciprocation of said connector in opposite directions; said opposed portions being located to prevent said stator from engaging said rotor to enable limited uninterrupted liow through said llow passage; and fluid ilow responsive means in said housing for driving said rotor.

12. A well drilling apparatus for a string of drill pipe having a drill bit at the lower end of said string, comprising: An elongated housing connectable at one end in said pipe string; a connector reoiprocable in the other end of said housing and connectable in said string; a drilling uid flow passage through said housing and said connector; said connector having a stern slidable in said body and an outward projection abutable with the end of said housing to limit inward movement of said connector in said housing; a ported stator at the inner end of said stem; means sealing said stator to said housing; and a rotor assembly rotatably disposed iu said housing above said stator and including a ported member adjacent said stator and a iluid ow responsive rotor above said ported member for driving the latter.

`v13. Well dr-illing apparatus for a string of drill pipe having a drill rbit on the lower end, comprising: an elongated housing connectable at its upper end to the drill string above it and having a longitudinally extending liuid passage; a liuid ilow interrupter rotor rotatably mounted in the housing passage; a liuid liow interrupter stator mounted within the housing passage downstream from the rotor7 said rotor and said stator each having liuid passageways therethrough oyclically intercommunicable with each other upon rotation of the rotor; and means for connecting .the stator rigidly to the drill bit below the housing and supporting the stator for axial movement toward and away from the rotor for variably restricting the flow of fluid through the housing.

14. Well drilling apparatus as in claim 13 that includes sealing means carried by the last mentioned means Vand engaging the walls of said housing passage whereby the stator acts as a piston lling the passage and exposed to pressure of liuid therein.

15. A fluid responsive, vibratory well drilling device for a string of drill pipe having a drill bit at the lower end of said string, comprising: a housing connectable at its upper end to the drill string and defining a fluid passage therethrough; and means for intermittently restricting the iiow of drilling iiuid through said passage to produce variable water hammer eiects responsive to variation of the fwei-ght of the drill string imposed on the device, said means including a pair of relatively rotatable interrupter parts in said passage and one of which is movable axially of the housing with respect to the other part to vary the `spacing between the parts and thereby the restriction imposed on fluid low ythrough the passage, connector means interconnecting said movable interrupter part to the drill string below the device, and means limiting the approach of the interrupter parts toward each other to prevent mutual contact whereby a predetermined minimum ow of fluid is maintained at all times.

References Qited in the lile of this patent UNlTED STATES PATENTS Beck lune 28,

Claims (1)

1. APPARATUS FOR IMPARTING VIBRATING MOTION TO A DRILL BIT, COMPRISING: A HOUSING ADAPTED TO BE DISPOSED IN A STRIP OF DRILL PIPE ABOVE THE DRILL BIT; MEANS IN SAID HOUSING FOR INTERMITTENTLY INTERRUPTING THE FLOW OF DRILLING FLUID THERETHROUGH INCLUDING AN INTERRUPTER STATOR AND AN INTERRUPTER ROTOR; SAID INTERRUPTER PARTS BEING SUPPORTED IN SAID HOUSING FOR RELATIVE MOVEMENT ONE TOWARDS THE OTHER; AND A CONNECTOR DEVICE CONNECTED TO ONE OF SAID INTERRUPTER PARTS FOR AXIAL MOVEMENT THEREWITH AND PROJECTING FROM SAID HOUSING FOR CONNECTION TO THE DRILL BIT IN THE DRILL STRING; SAID HOUSING AND SAID CONNECTOR DEVICE HAVING COENGAGED MEANS AXIALLY MOVABLE RELATIVE TO ONE ANOTHER FOR TRANSMITTING TORQUE TO THE DRILL BIT AND FOR ALLOWING MOVEMENT OF SAID INTERRUPTER PARTS ONE TOWARD THE OTHER.

Images