US2819039A

US2819039A - Deflecting tools

Info

Publication number: US2819039A
Application number: US477437A
Authority: US
Inventors: Onos M Lindsay; William G James
Original assignee: Eastman Oil Well Survey Co
Current assignee: Eastman Oil Well Survey Co
Priority date: 1954-12-24
Filing date: 1954-12-24
Publication date: 1958-01-07
Anticipated expiration: 1975-01-07

Description

Jan. 7, 1958 o. M. LINDSAY ETAL 2,819,039

DEFLECTING TOOLS 4 Sheets-Sheet 1 Fi led Dec. 24

A TTOfP/VE w Jan. 7, 1958 o. M. LINDSAY ET AL DEFLECTING TOOLS 4 Sheets-Sheet 2 Filed Dec. 24, 1954 fix; ,a 0/70: M, l/na Jay will/am afimesuw Ezvrozes I l Wm I! BY 5 a Z l fa M ATTO/P/VEVJ Jan. 7, 1958 o. M. LINDSAY ET AL 2,8

DEFLECTING TOOLS 4 Sheets-Sheet 4 Filed Dec. 24, 1954 RHII ATTORNEYS United States Patent DEFLECTING TOOLS Onos M. Lindsay, Long Beach, Calif., and William G. James, Denver, Colo., assignors to Eastman Oil Well Survey Company, Denver, Colo., a corporation of Delaware Application December 24, 1954, Serial No. 477,437

13 Claims. (Cl. 255-16) This invention relates to new and useful improvements in deflecting tools.

One object of the invention is to provide an improved deflecting tool for effectively drilling a well bore at an angle from the vertical whereby directional drilling of the well may be accomplished.

An important object of the invention is to provide an improved deflecting tool adapted to be connected in the lower portion of a drill pipe or string and having a radially extensible means for urging the lower portion of the drill pipe and the drill bit attached thereto laterally toward one side of the well bore, whereby subsequent rotation of the drill pipe and bit will result in. drilling the well bore at an angle with respect to the remainder of said bore.

Another object is to provide a deflecting tool having an improved deflecting element which is normally in a retracted positionand is adapted to be positively and mechanically moved radially outwardly by the imposition of the weight of the drill pipe thereon, whereby said element is automatically moved into expanded or extended position when the drill pipe weight is imposed upon the bit to perform the drilling operation.

Another object is to provide an improved deflecting tool having telescoping sections which are adapted to mechanically urge a deflecting element outwardly into a radially extended position and to positively maintain the element in such position when the sections are telescoped relative to each other; retraction of the deflecting element being automatically accomplished when the members are moved to an extended position.

A particular object is to provide a deflecting tool having a metallic deflecting element which is adapted to be moved outwardly by an expander which positively maintains the element in expanded position; said tool being arranged to be mounted in close proximity to or adjacent the drill bit whereby when the deflecting element is expanded, a constant radial pressure or lateral force is maintained upon the bit to constantly force said bit laterally of the well bore and thereby accomplish a directional drilling operation.

Still another object is to provide an improved deflecting tool, of the character described, which is simple in construction and which comprises a unitary assembly capable of being readily connected in the usual drill pipe; said tool, having its deflecting element mounted so that the element may remain stationary and will merely slide down the wall of the bore when the drill pipe and bit are rotated to perform the drilling operation.

A further object is to provide a tool, of the character described, including an improved orienting means whereby the deflecting element may be accurately oriented to properly position the deflecting element of the tool in a desired azimuthal position.

Another object is to provide a deflecting tool, of the character described, wherein the main portion of the tool comprises a pair of telescoping sections, the relative ice movement of which with respect to each other, control the expansion or radial extension or the retraction of the deflecting element; the deflecting element coaeting with a tapered expander which may be rotatable with the telescoping sections or which may be so mounted that said expander remains stationary while said sections rotate.

The construction designed to carry out the: invention will be hereinafter described, together with other features thereof.

The invention will be more readily understood from a reading of the following specification and by reference to the accompanying drawings forming a part thereof, wherein an example of the invention is shown, and wherein:

Figure 1 is an elevation of the lower portion of a drill pipe within a well bore and showing the improved deflected tool connected therein,

Figure 2 is a vertical sectional view of a deflecting Figure 7 is a longitudinal, sectional view of a modified form of the invention, showing the deflecting element in expanded position,

Figure 8 is a similar view with the deflecting element retracted,

Figure 9 is a horizontal, cross-sectional view, taken on the line 99 of Figure 7,

Figure 10 is a view, partly in section and partly in elevation of still another form of the invention, and

Figure 11 is a horizontal, cross-sectional view, taken on the line 1111 of Figure 10.

In the drawings the numeral 10 designates the usual drill pipe or drill stem which is adapted to extend through a well bore W and which is utilized to impart rotation to the drill bit 11 connected to the lower end of said drill pipe. present invention is arranged to be interposed between the drill pipe 10 and the drill bit 11 and said tool includes r a deflecting element which is generally indicated at B and which is movable radially of the body between a retracted and an expanded or extended position. When in an expanded position as illustrated in Figure 1, portions of the deflecting element engage the wall of the well bore W at one side of the bore just above and in close proximity to the drill bit 11 and said element functions to urge the lower portion of the drill pipe 10 in a direction away from the point of contact of the element with the wall of the bore. It is apparent that with the deflecting element in its expanded or radially extended position, the bit 11 is constantly urged toward that area of the wall of the well bore which is directly opposite the deflecting element and the subsequent rotation of the drill pipe and bit results in a drilling of the well bore at an angle with respect to the main. portion of said bore.

The deflecting tool A is clearly shown in Figures 2-6 and includes a pair of telescoping sections T and T1. The upper section T includes an elongate tubular body 12 having an axial bore 13 extending entirely therethrough, and the drill pipe 10 is adapted to have its lower end secured to the upper end of said body. An external The improved deflecting tool A comprising thev flange 12a is formed on the upper portion of the body and, the underside of said flange forms an annular shoulder 14. Nearer its lower end, the tubular body 12 is provided with outwardly extending drivelugs-or blocks .15.

The lower telescoping section T1 is formed of a generally cylindrical sleeve 16 which engages over the lower .portion of the tubular bod-y12 of .the upper section. The sleeve is provided with diametrically opposed slots 17, which slots receive the outwardly'directed drive lugs or blocks 15 on the body 12, whereby the upper section T is rotatively coupled to the lower section while permitting telescoping movement of the sections with respect to each other. "The lower end of the section T1 is formed with an expander .18 which is circularincross-section and whichisrgradually enlarged in diameter toward its lower end, wherebyits outer surface 18a 'is inclined downwardly and outwardly. ,The drill bit '11 is threaded into thelower end of the -.lower section T1, as clearlyshownrin Figure .2. The-deflecting element'B comprises a generally arcuate wedge1'9 which has its upper end pivoted at 20rto the flowertend of an outer sleeve 21. As shown in "Figure 6, the wedge 19 is disposed at one side of'the 'tool and extends only through a relatively small portionof .the circumference of the tool. The outer sleeve 21 surrounds the upper portion of .the sleeve 16 of the main section T1 and the lower-portion of'the upper'section T and'is' rotatably suspended from the upper surface 12b (of the external flange 12a on the body of said upper section. The outer sleeve 21 is retained against displacement "from'its'supp'ortin'g surface 12b by "a retaining collar '22.

The telescoping sections T andT-lare normally urged toward an extended position as illustrated in Figure 3 by a coil spring 23 which is "confined between the shoulder '14 on the upper section Tand the "upperend 16a of the sleeve '16 'of the 'lower "section T1. "When the sections are extended with respect to each other, the arcuatedeflecting element 13 is in a'retracted position, since its lower end is in a plane above the inclined surface 18a of the expander 18. At certain times it-is desirable to prevent rotation of the outer sleeve '21-'which carries the deflecting element B with respect to the sections and for this purpose the lower-section T1 has a pair of diametrically opposed recesses or grooves 24 (Figures 3 and 4) formed in its external surface. -As shown in Figure 3, each recess 'is open at its lower end and terminates at an external shoulder 24a formed on the body 16 of said lower section. A pair of pins 25 aresecured within the wall of the outer sleeve 21 and are located diametrically opposite each other, each pin "25 projects inwardly into the bore of the sleeve 21 and-is adapted to engage'within oneof therecesses 24 when the .sections are extended. At such time, the sleeve is locked againstlrotation with respect to the-lower section T1, and since .the 'lower section is 'rotatively coupled to the upper section at all.times, the-deflecting element Bis locked againstrotation .with .respcct tothe drill pipe. When the sections are moved into a telescopedgposition, as illustrated in Figure 2,:each pin 25 moves out .ofits recess 24 to :the-dottedline position 2551 in Figure 3, whereby-the. sections may be rotated-while the wedge element B and its carrying sleeve 21 'may remain stationary. Although a pair of 'pins 25 and recesses 24 are-illustrated,:it is evident that only 'onesuch pin and recess-would suflice. To facilitate rotationof the upper section with respect to the .outer sleeve, a suitable bearing surface .27 may be provided between the upper-end of the-sleeve'and theretaining collar'22.

It is apparent that when the pin 25 is engaged within its recess 24, the deflectingelement is locked-in a-fixed position with respect tovthe drill pipe. Bylocating .a magnet 28 (Figure ,1) .in the drill pipe in a known radial position orrelationship tothe deflectingelement,

it is possible todetertnine theradial position :orazimuth of the deflecting element by known methodsv of ,botttomhole orientation. For example, a method of orientation which may be employed is that shown in the patent to Miller, 2,327,658, or Hyer, 2,120,670. With the magnet 28 in a known radial relationship to the deflecting element when the latter is locked against rotation on the drill pipe, a suitable well survey instrument illustrated in dotted lines in Figure 1, may be lowered within the pipe to an elevation substantially opposite the magnet; thereafter the instrumentis operated to record the azimuthal' position of the-magnetand bysubsequent examination of the records so :made, the compass position 0f the deflecting element may be readily determined after the tool has been loweredinto position within the .well bore.

In the operation .of the tool, the parts are normally in the position shown in Figure 3 with the sections T and T1 in an extended position. In such position, the deflecting element is in itsretracted position and each orienting pin 25 is engaged in its recess 24. As explained, the drill pipe is connected to the upperscction T which is coupled to the lower telescoping section T1 through the drive lugs 15 and'slots 17.

When the tool reaches bottom, .the compass position of thedeflecting element B may be determined by ascertaining the position of the magnet 28 by means .ofany well-known orientation method. Thereafter, the drill pipe may be rotated tollocate the deflecting element in the desired az'imuthalposition.

Upon being lowered to bottom, the drill bit strikes the bottom of the well bore and thereafter the weight of the drill pipe is imposed upon the tool. This causes a further telescoping of the upper section T with respect to the lower section T1, such movement being permitted by the coil spring 23. The downward movement of the upper section Twith respect to the lower section T1 moves the arcuate deflecting element B downwardly along the in clined face 18a of the expander .18 to cause the deflecting Y elem'ent'ot'be moved -radially outwardly into contact with the wall of the well bore W. At the same time, the downward movement of the upper section with respect to the lower section results in disengaging the pins 25 from the recesses 24 because the outer sleeve 21 moves downwardly with the uppersection. The connection between the outer sleeve 21 and the lower section T1, as effected bythe pins -25and recesses24, is released and thereafter the sections Tand T1 may be rotated with respect to said outer sleeve.

When the deflecting element B is moved radially outwardly, said element contacts the wall of the bore and applies a lateral pressure to the drill bit 11 to urge the bit in a direction which is opposite the position of the deflectingrelement, and therefore .thebit is urged toward one side of the 'bore. By proper orientation of the element, the drill bitis urged laterally in a desired compass direction 'so that subsequent rotation of the drill pipe and of the bit will perform the drilling operation. So long as the weight of the pipe isimposed upon-the tool, the sections T and T1 remain in fully telescoped position and maintain the deflecting element in its radially expanded position. Obviously, the element remains stationaryduring rotation of the drill pipeand drill bit, and as drilling proceeds, the deflecting element merely slides down the wall of the Well bore but constantly maintains a lateral pressure on the bit to urge .it toward the opposite wall. It is preferable that the element 'B :be located in close proximity or adjacent to the drill bit 11 so that the required constant lateral pressure can be maintained throughout the drilling operation.

In Figures 7 and 8, a modified form of the invention is shown. In thisform, the tool A1 is constructed of an upper telescoping section T3'anda lower telescopingjsection T4. The upper section comprises a sub or coupling member 30 which has connection with the drillpipe 10.

The sub 30-is.-tubular, being formed with a bore 31, and

asleeve 32 is (connected to and dependsfrom said-sub.

astaoss The lower end of the sub is formed with downwardly extending clutch teeth 33. i

The lower telescoping member T4 includes a tubular body 34, having an axial bore 35. A wash tube or condoctor 36 is threaded into the upper end of the bore and extends upwardly through the bore 31 of the sub 30; a suitable packing 37 seals off around the tube and said tube functions as a conductor for establishing communication between the bore a of the drill pipe and the bore 35 of the body'34. The upper end of the body 34 is formed with clutch teeth 38 which. are adapted to interengage the teeth 33 of the sub 30 when the sections T3 and T4 are in fully telescoped position. The

clutch teeth

33 and 38 are of considerable strength and function to carry the load when rotation is imparted from the section T3 to the section T4 during the drilling operation. A coil spring 39 which is disposed between the sub 30 and the body 34 exerts its pressure to constantly urge the sections toward an extended position.

The lower end of the body 34 of the lower section T4 is formed with an expander 40 having an inclined expanding surface 40a and the drill bit 11 is connected to the lower end of the body 34. The body 34 is rotatively connected to the sub 30 by splines 41 formed on the body which coact with splines 42 provided within the bore of the sleeve 32; as explained, the sleeve 32 is connected with and depends from the sub 30 of the upper section T3.

A deflecting wedge element 43 which is arcuate in crosssection (Figure 9) is pivotally mounted on a pin 44 which is secured within the lower end of an outer sleeve 45 formed of interconnected sleeve members. As is clearly shown in Figures 7 and 8, the sleeve 45 surrounds the lower section T4 and also surrounds the sleeve 32 as well as the lower portion of the sub 30 of the section T3. The upper end of the outer sleeve 45 is adapted to abut an external shoulder 46 formed on the sub 30 and suitable bearing material 47 may be provided on the upper end of said sleeve. The sleeve 45 is suspended from a shoulder 48 formed at the lower end of the sleeve 32, and additional bearing material 49 may be provided at this point.

For locking the outer sleeve 45 against rotation with respect to the sections and to the drill pipe to permit orientation, an orienting pin 50 and a co-acting notch 54 are provided. The pin 50 is adapted to extend inwardly from the sleeve 45 into an annular recess 51 which is formed in the exterior of the body 34 of the lower section T4. The recess 51 is defined by an upper shoulder 52 and a lower shoulder 53 and the space between the shoulders limits the movement of the outer sleeve in an axial direction with respect to the section T4. A notch or recess 54 extends upwardly from the shoulder 52, and when the orienting pin 50 is engaged within the notch, the outer sleeve is coupled to the lower section T 4. At this time the deflecting element 43 is retracted and the sections T3 and T4 are extended as shown in Figure 8.

The operation of this form is substantially similar to the other form with the tool being connected between the drill pipe and the drill bit. During the lowering of the tool into the well the parts are in the position shown in Figure 8 with the spring 39 holding the sections extended. In such position, the

clutch teeth

33 and 38 are disengaged, but a rotative connection between sections T3 and T4 is set up through the

splines

41 and 42. The outer sleeve 45 is locked against rotation by the orienting pin and the deflecting element 43 is retracted.

After proper orientation of the deflecting element, the bit is lowered to bottom and the drill pipe weight is imposed thereon to telescope the parts. This moves the sections to the position shown in Figure 7 which releases the orienting pin 50 from the locking recess 54 and causes the deflecting element 43 to be moved radially outwardly along the inclined surface 40a of the expander 40. As is the case of the deflecting element B in the first form, a

latet l Pressure is imparted to the drill bit by contact of 75.

the deflecting element 43 with the wall of the bore. At the same time that the element is expanded, the

clutch teeth

33 and 38 are engaged to set up a direct drive from the drill pipe through the sections T3 and T4 to the drill bit, whereby subsequent rotation will carry out the drilling operation. It is evident that as long as the drilling operation is continued the deflecting element remains in its radially extended position, and since the orienting pin 50 has been disengaged from its recess, the sections of the tool may be rotated relative to the outer sleeve 45 and said deflecting element. Therefore, the element merely slides down the wall of the well bore and applies a lateral pressure as the drilling proceeds.

Still another form of the invention is shown in Figures 10 and 11. This modification is substantially the same as the form shown in Figures 7-9 with the exception that a different type of deflecting element is provided. As shown in Figure 10, a sleeve 45a is substituted for the sleeve 45 and a body 34a is substituted for the body 34. The body 34a which forms the main member of the lower telescoping section T4 is not provided with an expander such as 40, but rather has a substantially cylindrical surface on which an expander is mounted. The expander 140 is rotatably supported on a shoulder 34b of the body 34a and said expander is formed with a trio of expander surfaces 60. Each expander surface has an arcuate deflecting wedge element 61 keyed thereon, and each deflecting element is connected through a pivoted link 62 with the lower end of sleeve 45a. As is clearly shown in Figure 11, the deflecting elements 61 are substantially arcuate in cross'section and .are disposed all on one side of the tool.

For locking the expander sleeve 140 and the deflecting elements which have connection thereto against rotation on the body 34a, said sleeve is provided with an orienting pin 63 adapted to coact with a locking recess 64; the orienting pin engages said recess when the sections T3 and T4 of the tool are in extended position.

The operation of this form is exactly the same as that of the form shown in Figures 7-9. When the sections T3 and T4 are extended, the orienting pin 63 engages the recess 64 and the expander sleeve 140, together with the deflecting elements 61, are locked against rotation with respect to said sections. At this time the deflecting elements 6i. are in a radially retracted position.

When the device has been lowered into the well bore and the deflecting elements properly oriented, the sections T3 and T4 are moved into fully telescoped position as shown in Figure 10. This moves the deflecting elements 61 downwardly on the inclined surfaces 60 of the expander to thereby radially expand said elements. At the same time, the orienting pin 63 is disengaged from its recess and a direct drive is set up between the sections through

clutch teeth

33 and 38. Rotation of the drill pipe will rotate the sections T3 and T4 to impart rotation to the drill bit 11, and since the deflecting elements are expanded a lateral pressure is applied to the bit. Since the expander sleeve 140 has been disconnected from the body 34a of the lower section T4, it is obvious that the defleeting elements 61, the expander sleeve 140 and the supporting sleeve 45a all remain stationary as the drill pipe and its connected parts rotate to rotate the drill bit and perform the drilling operation. The main diflerence between the form shown in Figure 10 and that shown in Figures 7-9 is that the expander in Figure 10 does not rotate during the drilling operation, while in Figures 7-9 the expander 40 is rotatable with the drill bit.

In all forms of the invention, the deflecting element or elements is or are positively urged radially outwardly during the drilling operation, and therefore a constant lateral pressure is maintained against the drill bit. Since the deflecting element or elements may be properly oriented, it is apparent that a directional drilling operation may be accomplished.

The foregoing disclosure and description of the invenagar-9,039

'7 tion is "illustrative and explanatory "thereof and various changesrin the size, shape and materials,as well as in the details of Lthe illustrated construction, may be .made within the scope of the appended claims without departing from the spirit of the invention.

What we claim is:

1. A deflecting tool including, an upper tubularsection, a lower tubular section in telescoping relationship with respect to the upper tubular section, means interconnecting the sections for axial movement relative to each other whereby the sections.may be moved to a'first position in which the sections .are extended and .to a second position in which said sections :are more fully telescoped, means for rotatively .connecting'the sections in all positions of the secitions, springmeansgnormally urging the sections towardsaid first-extended position, an .expander-element onjthe lower portion of the lower section and havinganexternal inclined surface, and a radially movable deflecting element carried by the upper section and disposed in a plane abovefthe expanding surface of the expander when the sections are in said first position, movement of the sections to said second position effecting a movement of said deflecting element with respect to the inclined surface ofthe expander whereby said deflecting element is moved radially outwardly when said sections are in. said second position.

2. A deflecting toolas set forth in claim 1, together withmeans for rotatablymountingthe deflecting element on said upper section, whereby the sectionsmay be rotated with. respect to the element.

3. A deflecting tool as set forth in claim .1, Qgether withmeans forvrotatably mountingthe. deflecting element on :said upper section, whereby the sections may be rotated withrespect to theelement, and means operable when the sections are in said .firstnposition for locking the deflecting element against rotation with respect -to said sections, said lastnamed means unlocking the deflecting element for rotation independently of the sections when said sections are in said second position.

.4. A deflecting tool including, an upper section, a lower section in telescoping relationship with respect to the upper section, means interconnecting the sections for axial movement relative to each other, said sections being movable axially with respect .to each otherfrom a first extended position to a second more fully telescoped position, spring means normally urging the sections toward said first extended position, means rotatively connecting the sections in all positions of the sections, an expander having anexternal inclined expanding surface mounted on the lower section below the upper section, an outer sleeve rotatably suspended from the upper section, and aradiallymovable deflecting element suspended from the upper section andlocated in a plane above the expander when the sections are in extended position, said deflecting element being movable downwardly relative to the inclined. expanding surface of the expander when the sections are telescoped, whereby the coaction between said expander and the element moves said element outwardly in a radial direction.

5. A deflecting tool including, an upper section, a lower section in telescoping relationship with respect to the upper section, means interconnecting the sections for axial movement relative to each other, said sections being movable axially with respect to each other from a first extended position to a second more fully telescoped position, spring means normally urging the sections toward said first extended position, meansrotatively connecting the sections in all positions of the sections, an expander having an external inclined expanding surface mounted on the lower section, an outer sleeve rotatably suspended from the upper section, a radially ,movably deflecting element suspended from the .upper section and located in a plane above the expander when the sections are in extended position, said deflecting element'being movable downwardly relative to the inclined expanding'surface of the expander when the -sections-areitelescoped, whereby the coaction between said, expander and the element moves said element outwardly in a radial directionyand means operable rwhenwthe sections are extended for locking the outer-sleeve against-rotation with respect to the sections.

v6. A deflecting toolas set forth in claim 5, wherein the locking means comprises a-pin within the bore of the outer sleeve and ,fl IGCfiSSfOI'lIlCd in'the external surface of theglower section.

7. A-deflecting tool assctforth in claim 4, wherein the expander is formed-asan integral part of the lower section.

8. A deflecting tool as set forth in claim 4, together with means for, rotatably mounting the expander on the lower section, ,means connecting the deflecting element to the expander toprevent rotative movement while permitting longitudinal movement, and locking means operable when the sections are extended for locking the expander. against rotation relative to the sections when the sections .are. extended relative to each other.

9. A deflectingtool including an-upper section, a lower section in telescoping relationship with respect to the upper section, means interconnecting the sections for axial movement relative to each other, said sections beingmovable axially with respect to each other from a first -extended to a second more fully telescoped position, resilient means normally urging the sections toward an extended ,position, means 'rotatably connecting the sections in all positions of said sections, an expander having ,an external inclined expanding surface mounted on thelowersection below the upper section, an outer sleeve rotatably suspended from the upper section and surrounding .aportion of the .lower section, an orienting projection cxtendinginwardly'from the bore of ,the outer sleeve and adapted to engage an orienting recess 'formedfinthe surface of thelower section, said orienting projection'Ibeing engaged within its co-acting recess whenjthesseotiQns are in, saidjfirst position to latch the outer ,sleeve against rotation with respect to the sections, said projection being disengaged from the recess when the sections ,are ,moved to ,said second position wherebythesections. may be rotated relative to the outer sleeve,, and a radially movable deflecting elementsuspendedffromthe outer sleeve and located in a plane above the expanding surface ofthe expander when the sections are in said first position, said deflecting element being movable downwardlyrelative to the inclined expanding surface ,ofrthe expander when thesections are more fully telescoped, whereby the co-,a ction between the expander and the elementmoYQsthe-elcment outwardly in a radial direction.

10..A deflecting toolas set forth in claim.9, together with clutch members .on the upper and lower sections, Whichclutchmernbers-are adapted to engage each other when,thesectiousaremovedto Said more fully telescoped position to ,providea ,directrotative drive between the sections.

.11. .A ,deflectingtoolaasset forth in claim 9, wherein the expanderis rotatably mounted upon the lower section.

12. A.,defle.ctin g .t0ol.;a,dapted@to vhe,lowered in a well bore by ,the ..dri;lling,string and being positioned adjacent the drill bit,:cO mPrising. an upp,er section, a lower section having ,,a telescoping connection with the upper section,

said sectionslbeing moyableaxially with respect to each other from an extended position to a retracted position,

resilient meansinormally .urging the sections toward an extended position, means ,rotatably connecting the sections ,irnall positions of \the sections, anexpanderhaving anexternalsurface mounted on the lower section below the ,uppersection, .a, r adially movable deflecting element arranged to ,c,ogpera te with ,saidsurface when said sections are moved from v,theirgextended position to a retractefd position and thereby gradually move radially outwardly with respect to'thebit to'enga'ge the bore *and' impartg'lateral thrust-to-the*bit, "said elementbeing positioned within the gauge of said bit and in a plane above the expander when the sections are in extended position, and said element being positioned outside of the gauge of the bit when said sections are in a retracted position.

13. A deflecting tool, as set forth in claim 12, together with latching means between the deflecting element and the lower section, said latching means comprising a recess and a projection engageable within said recess, said elements which comprise said latching means being disposed one on the deflecting element and the other on the lower section, .the position of said projection and recess being such that the projection is engaged with the recess when the upper and lower sections are in an extended position with respect to each other to thereby lock the deflecting element against rotation relative to said lower section and said projection is disengaged from said recess when the sections are in retracted position, whereby the inner section may be rotated independently of said deflecting element.

References Cited in the file of this patent UNITED STATES PATENTS 10 2,120,670 I-Iyer June 14, 1938 2,179,567 Strength Nov. 14, 1939 2,196,944 Sharp Apr. 9, 1940 2,329,597 Diehl et a1 Sept. 14, 1943 2,643,859 Brown June 30, 1953