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Publication numberUS3301581 A
Publication typeGrant
Publication dateJan 31, 1967
Filing dateSep 30, 1965
Priority dateSep 30, 1965
Publication numberUS 3301581 A, US 3301581A, US-A-3301581, US3301581 A, US3301581A
InventorsWinberg Douglas F
Original AssigneeRobbins & Assoc James S
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Drilling shafts
US 3301581 A
Abstract  available in
Images(5)
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Claims  available in
Description  (OCR text may contain errors)

1967 D. F. WINBERG 3,301,581

DRILLING SHAFTS Filed Sept. 30, 1965 5 Sheets-Sheet l INVENTOR ATTORNE Y5 Dal/Gus A W/Msem;

2W4, 6 4 g fix-My Jan. 31, 1967 Q V wmB G 3,301,581

DRILLING SHAFTS Filed Sept. 30, 1965 '5 Sheets-Sheet z INVENTOR Dal/Gus A VIM/852G ATTORNEYs 19.67 v D. F. WINBERG DRILLING SHAFTS Filed Sept. 50, 1965 5 Sheets-Sheet :5

' Filed Sept. 30, 1965' I D. F. WINBERG DRILLING SHA'PTS Jan. 31,. 1967 5 Sheets-Sheet 4 INV DOUGLAS E BY Kl 7 0 K (jug/j A T TOR NE YS Jan. 31, 1967.

Filed Sept. 30, 1965 D. F; WINBERG 3,3(31581 DRILLING SHAFTS United States Patent This application isa continuation-impart of copending application Serial No. 314,142, filed October 7, l963, a nd entitled Sectional DrillingShafts, and I now Patent No. 3,258,283. V p

The present invention relates to improvements in drilling shafts or stems, and more particularly'to the provision of a high torque .drilling shaft of sectional constructionand characterized in' part by. a novel nonthreaded tool joint construction. '1 4 In earth boring operations according to therotary drilling method, the work: is. accomplished through the use of an elongated drilling shaft, at. the lower extremityof which is placed the cutting tool. [Through the inter mediacy of the drilling shaft the cutting tool is rotated and either pushed or pulled (e.g. as in a. raise drilling.

11:; joint components; In'other forms of tool joint accord-. ing to the invention the pin and box opening are comple--- operation) against the worktace of theinaterial being drilled. Basically, the. drilling shaft, consists of-the cutting tool, drill collars, lengths of drill pipe successively interconnected by .tool joints,. 7, and the. kelly 'or grief stern by which the shaftisattachedtoa drive. mechanism.

Known .vconventionaltool 'joints 'are merely threaded connections consisting of an internally threaded box constituting an end of a first member or component of the drillig shaft (e.g. a length of drillpipe) and.. an. externally threaded pin constituting an end of asecondfrnernher or component of saidshaft. The said first and sec-.

ond members or com-ponents are joined or coupled-to.-

gether by. merely screwing-the said pinfint'o the saidbox, This type of joint construction provedto be unsatisfactory for use in high torque operations, such as in raise drilling operations, for example, becausethe high torque to which the drilling shaft is subjected in such operations tends to. tie the threads .together, making it extremely difiicult,

and in some cases practically impossible, to unthread the joints for removal of lengths of drill pipe from the upper end of the drilling shaft. In raise drilling operations, tensile forces also account forthread distortionor tying. This is because the drilling shaft is in tension and the tensile forces .are carried by or. transmitted. through the joints solely by the threads.

A further disadvantage of threaded tool joints is that when such are employed each length of .drill pipe being added to or removed from the drilling shaft .must be both rotatedand moved endwise an amount equal to the pitch of the threads per each threehundredand sixty degrees (360) of rotation. Since in most installations the lengths of drill pipe are'too large and too heavy to be handled by hand, the drilling rig must be equipped with a mechanism for causing synchronous rotary and rectilinear movement of the drill pipe. Known mechanisms of this sort are highly complicated, are subject to breakdowns that stop the work, and in general are quite costly,

disadvantages that accompany the use of threaded tool joints. The unique-tool joint construction provided by- .z; j effecting synchronous rotary and rectilinear movements of the lengths of drill pipe being added to or through side wallmeans of said pin and box, and defined:

3,301,581 v Patented Jan. 31, 1967 ice the invention is in the nature of slip joint, and completely obviates the problem of thread tying or distorti'on, .and further-obviates the need of a mechanism for removed from the drilling shaft. e

Y. -Characteristically, the tool joint of the present invention comprises an elongated non-threaded pin interfittingly en.-

gageable within the elongated non-threaded socket opening of a box, and a coupling assembly consisting of a pair of plug elements, at, least a portion of which is frustro-coni cal inv shape,- which elements are insertable into diametri cally opposed frustro conical-. bores extending laterally by two pairs of complementary inwardly tapering openings formedin said side-wallmeans; and a coupling bolt insertable through an axial bore in one of the cones andthreadably engageable into an axial bore of the other.

In some forms of tool joint'according to the invention, the pin and box opening are cylindrical, and compressive stresses are essentially. transferred from one length of.

drill pipe to the next by way of surface-to-surface contact betweenshoulder and terminal portions of the pinand box mentary tapered, and the compressive stresses are transferred by way of surface-to-surfacev contact between the contactingside walls of the pin and the box opening. In

all forms the tensile andtorsional stresses are transmitted through the joint from one length of drill pipe to the-next length by the coupling assembly.

In the joint form involving a cylindrical pin and a cylindrical box opening the tolerances at the joint between the several surfaces of said pin and box opening are relatively close, in the order of a thousandth of an inch, for example. In the joint form involving a tapered pin and matching tapered box opening the pin is preferably driven into tight contact with the inside wall of thebox opening. Owing to either the close tolerance or tight 1 fit, in both forms the joint behaves during bending in essentially the same Way as an intermediate straight section During bending the curvaand has an opening in its mid-portion that is generallyaligned with the tapered side wall openings. The box portion of the joint is essentially the same as before. Also as before, the coupling assembly comprises a pair of plug elements and an interconnecting bolt, but such plug elements are somewhat different in form. They are longer and are each characterized by an inwardly tapering, preferably frustro-conical, outboardportion, and a generally straight, preferably cylindrical, inboard portion. The outboard portions of such elements fit into the side wall bores as in the previous forms, and the inboard portions thereof snugly fit into the opening in the transverse support member. Owing to this arrangement, both ends of the plug elements are supported by pin joint component, and the coupling bolt is centrally supported against bendmg.

The novel slip joint constructions of the present invention are not limited in use to the interconnection of successive lengths of drill pipe, but rather may be used for connecting together any two successive element or components of the drilling shaft, such as the drill bit or cutterhead to the drill collar, the drill collar to the drill pipe, and the drill pipe to the kelly, for example. Also, such slip joint constructions may have utility in other installations completely foreign to earth boring but requiring the interconnection of tubular and perhaps solid members.

Another principal object of the invention is to provide, as a new article of commerce, an improved form or type of drill pipe, such form being characterized by an generally straight tubular body or intermediate portion, a right cylindrical or frustro-conical pin at one end, and a box at the other end having a right cylindrical or frustroconical box opening, with diametrically opposed, inwardly tapering openings extending laterally through both the pin and the box, and with the openings in the pin corresponding in taper to the openings in the box. According to the invention, the drill pipe may be either internally or externally upset at the ends and the joint components, i.e., the pin and the box, may be fashioned from the upset end portions. Alternatively, the pin and box may be swaged onto the ends of a cylindrical section of drill pipe, or the pin and/or the box may be constructed as separate fittings to be welded or otherwise suitably fastened to the ends of a length of drill pipe.

In comparison to conventional threaded tool joints, ad ditional advantages gained by using the non-threaded, slip joint of the present invention include:

(a) A drilling shaft constructed according to the invention and employing the slip joint of the invention, is more readily assembled and disassembled, both in terms of the handling required and speed;

(b) The coupling assembly is wear compensating, i.e., wear on the plug elements and/or the frustro-conical bores is taken up by merely threading the coupling bolt an additional amount into the interiorly threaded plug element, so as to locate the plug elements closer together in the bores and put them once again in tight engagement with the side surfaces of such bores; and

(c) The several elements of the coupling assembly are relatively inexpensive to manufacture and hence are inexpensive to replace when they wear out or are lost.

These and other objects, features, advantages and characteristics of the drilling shafts, drill pipe and non-threaded tool joints of the present invention will be apparent from the following description of typical and therefore nonlimitive embodiments thereof, taken together with the accompanying illustrations wherein like letters and numerals refer to like parts, and wherein:

FIG. 1 is a small scale view of a raise drilling machine in operation as same is forming a pilot hole on a downward pass, the separation between the upper level and the lower level shaft between which the raise is to run being fragmented for simplicity of illustration, with said machine being equipped with a drilling shaft embodying features of the present invention;

FIG. 2 is an enlarged scale detail view of a tool joint construction typifying one form of the invention, with the coupling bolt shown in elevation in such view, and with the remaining elements shown in section;

FIG. 3 is an exploded perspective view of the tool joint of FIG. 2;

FIG. 4 is a view partly in medial longitudinal section, and partly in elevation, of a length of drill pipe, shown in the form of a one-piece casting;

FIG. 5 is a view similar to FIG. 4, showing a modified form of construction of the length of a drill pipe, namely, a composite form;

FIG. 6 is a cross-sectional view of the length of drill pipe shown in FIG. 4, such view being taken substantially along the line 66 of FIG. 4;

FIG. 7 is a cross-sectional view of the length of drill pipe shown in FIG. 5, such view being taken substan tially along line 7-7 of FIG. 5;

FIG. 8 is an exploded elevational view of a fragmented lower portion of the drill stem such view illustrating a drill collar especially constructed for coupling a conventional drill bit to the lowermost length of drill pipe;

FIG. 9 is a view like FIG. 4, but of a modified form of drill pipe;

FIG. 10 is a view like FIG. 2, but of a joint construc tion involving the FIG. 9 form of drill pipe;

FIG. 11 also is a view like FIG. 4, but entirely in medial section and of still another modified form of drill FIG. 12 also is a view like FIG. 2, but of a joint involving the FIG. 11 form of drill pipe and the modified form of plug elements; and

FIG. 13 is a cross-sectional view taken substantially along line 1313 of FIG. 12.

Referring to the several figures of the drawing more specifically, the raise drilling mechanism illustrated in FIG. 1 in general comprises a crawler or tractor C, a base member or footing B, and a rotary drilling rig D. The rotary drilling rig D includes a gear reducer 10 mounted on guide sleeves 12 for rectilinear movement along mastlike guide columns 14. A kelly or grief stem (not shown) is attached to the output of shaft (not shown) of the gear reducer 10. A sectional drilling shaft S is rotated and carried by the said kelly. Such drilling shaft includes an internal fluid passageway extending from end to end through which a suitable drilling fluid is delivered to the cutting tool and the work face of the hole being drilled.

The drilling operation involves first boring a small pilot hole from the upper level UL where the drilling mechanism is situated down to a lower level LL. The pilothole drill bit DB is of suitable size to leave the pilot hole PH just slightly larger than the drill stem S. Drilling of the pilot hole PH is commenced with the gear reducer 10 in its raised position. Then the drilling shaft S is rotated while the gear reducer 10 is hydraulically or otherwise suitably urged downwardly. When the drilling has proceeded to the point where the guide sleeves 12 and the gear reducer 10 have reached about their lowermost extent of travel on guide columns 14, the downward movement thereof is ceased, the portion of the drilling shaft S then in the ground is uncoupled from the kelly, and the gear reducer 10 is returned to its raised position. A length of drill pipe L is then coupled between the kelly and the portion of the drilling shaft S that is in the ground, and then the drilling is resumed. The pilot hole drilling operation thus progresses with' successively introduced lengths L of drill pipe and. downward work strokes until the pilot hole is formed through the mineral formation M between the upper level UL and the lower level shaft LL. 7

With the pilot hole .pH formed, the pilot hole drill bit DB is removed from the drill stern S and a raise cutterhead (not shown) is connected to the lower end of the drill stern S. The raise hole drilling operation is then commenced. This involves simultaneously rotating and hydraulically lifting of the drilling shaft S and the raise cutterhead. The raise hole boring operation proceeds with cyclic performance of a working lift of the drilling shaft S and raise cutterhead, and uncoupling and removal of the upper lengths of drill pipe, a lowering of the gear reducer 10, a recoupling of the drilling shaft S to the gear reducer 10, and a further raising of the drill stern S and cutterhead and so on until the raise hole is formed between the lower level shaft LL and the upper level UL.

For a more extensive and comprehensive discussion and disclosure of a typical raise drilling technique, and the mechanism employed therein, reference is made to the copending application of Cannon et 211., Serial No.

224,756, filed September 19, 1962, and entitled Raise- Drilling Method and Mechanism. To the extent that it may be necessary for a clearer understanding of the present invention, the disclosure of such application is expressly incorporated herein by reference.

Turning now to the features of the present invention, FIG. 4 shows a length L of drill pipe typifying one aspect of the invention, and FIG. 2 illustrates a tool joint J typifying another aspect of the invention.

FIGS. 2-13 are substantially drawn to scale and de- .pict rather accurately the relative proportions of the several parts of the drill pipe lengths L and of the various coupling elements typifying the invention.

According to the invention, the lower endof a length L of drill pipe is in the form of a right cylindrical pin 16 and the upper end of such length L is in the form of a box 18. Unlike known conventional pins and boxes, pin 16 and box 18 are not threaded. Rather, they form male and female parts, respectively, of what may be termed a non-threaded, slip joint J, retained by a cross pin coupling assembly 20, hereinafter to be described.

As illustrated in FIG. 5, for example, the length L of drill pipe is shown to include an internal upset at each of its ends, designated 22, 24, respectively. However, it is to be understood that in certain installations, e'.g., in installations requiring greater fluid volumes and reduced pump pressures, the upsets may be external so as to make possible a larger internal diameter. The purpose of the upsets 22, 24 are to give additional wall thickness and strength to the ends of the lengths L of drill pipe.

Referring now to FIG. 2 in particular, the pin 16 of an upper length L of drill pipe is shown fully accommodated within a right cylindrical opening provided in the box 18, of the lower adjacent length L. An interior shoulder 26, formed at the bottom of box 18, abuts the generally squared off terminal 28 of the pin 16. In similar fashion, the generally squared oif terminal 32 of the box 18 abuts against an external shoulder 34 formed at the base of pin 16. A relatively close tolerance is required at joint J between the inside wall of box 18 and the outside wall of pin 16, between internal shoulder 26 and terminal 28, and between terminal 32 and external shoulder 34. This tight fit of the pin 16 within the box18 makes joint J behave during bending of the drill stem S, such as during the pilot hole boring operation wherein the drill stern S is in compression, essentially the same as if the drill stem S were not broken at such joint I. The close tolerance between the outer cylindrical surface of pin 16 and the inner cylindrical surface of box 18 prevents the pin 16 from rocking within the box 18. Also, the close tolerances between the respective pairs of abutting surfaces of the terminals 28, 32 and the shoulders 26, 34 enhances the resistance of the joint I to rocking since each prevents the displacement of the surface against which it abuts, and such displacement is necessary in order for relative angular rnovernent, i.e. rocking between adjacent lengths of drill pipe,

to occur.

As shown. in FIG. 2, for example, inwardly tapered openings 34, 36 extend through the cylindrical wall of box 18 at diametrically opposed locations and are paired with inwardly tapered openings 38, 40 extending at diametrically opposed locations through the cylindrical wall of pin 16 so as to form a .pair of diametrically opposed, frustro-conical bores at thejoint J. The coupling assembly 20'includes a first frusto-concial plug member or cone 42 which is insertable into one pair of inwardly tapering openings, say openings 36, 40, for example, a second frustro-conical plug member or cone 44, insertable into the other pair of aligned tapered openings (i.e., openings 34, 38), and a coupling bolt 46. As shown, cone 42 includes a bore 48 sized to accommodate the shank of coupling bolt 46, and a countersink 50 sized to receive and accommodate the head 52 of such bolt 46. Cone 44 is shown to-be internally threaded at 55 (FIG. 3) and in effect is'a nut into which the threaded end 54 of bolt 46 is'screwed. Owing to their tapered construction, cones 42,44 are easily inserted into the frustroconical bores formed by paired openings 34, 38 and 36, 40, respectively. The coupling bolt 56 is then easily inserted through cone 42 and screwed into cone 44.- Cone 44 is prevented from turning by the insertion of an appropriate tool (not shown), similar toa screwdriver, into a slot 56, or the like, provided in the outboard end of cone 44, as the coupling bolt 46 is being turned by another appropriate tool, the end of which'is inserted into the socket opening 58 (shownas being of hexagonal shape merely by way of typical and therefore non-limitive example). The threading ofi bolt 46 into cone 44 draws the cones 42, 44 together and wedges them tightly in the openings 34, 38 and 36, 40.

As an added advantage, owing to the taperednature of cones 42, 44 and the bores composed of openings 34, 38 and 36, 40, the coupling assembly automatically compensates for its own wear and the wear of openings 34,

38 and 36, 40. As the cones 42, 44 and/or thepairs of openings 34, 38 and 36, 40 Wear, the bolt 46 is merely threaded a little bit further into cone 44 in order to take up'the wear and place the frustro-conical surfaces of the cones 42, 44 into tight engagement with the frustroconical surfaces of the pairs of openings 34, 38 and 36, 40, respectively. Also, owing to the symmetrical construction of the coupling assembly about the center line axis of the drilling shaft, the forces carried by said coupling assembly are balanced relative to said center line. Each length L of drill pipe is provided with. wrench receiving slots, Such as indicated in FIG. 6 at'60, 62. During the raised hole drilling operation a holding wrench (not shown) is used to engage the drilling shaft at such slots 60, 62 and prevent it from dropping downwardly into the hole when the upper length of drill pipe is being removed therefrom. Since there are no threadsat the joints, there is no rotation of'the uppermost lengthv of drill pipe relative to the remaining portion of the drill stem, and hence the wrench is not needed to hold-the drilling shaft S against rotation while lengths L are being added. During pilot drilling the drilling shafts need not be held against endwise movement because it is fully supported at its lower end by the contact of the drill bit DB with the bottom of the pilot hole PH.

The composite form of drill pipe, designated L' in FIG. 5, has substantially the same overall configuration as the one-piece offset form heretofor described. However, according to this form of the invention the pin 16 and the box 18' are originally formed as separate elements having inboard end portions 64, 66, respectively, of reduced diameter and adapted to tightly interfit within the cylindrical body portion 68. The pin 16' is welded to one end of a generally straight body portion 68 mm, and the box 18 is welded to the other end of the body portion 68 at 72. i

As shown in FIG. 8, a double box collar C, one box 74 being internally threaded at 76 and the other 'box 18 being constructed according to the invention, may be used for interconnecting the pin16 of the lower-length L of drill pipe with a conventional drill bit DB having a threaded pin 78. 'No particular harm is done by the threads of this threaded connection at' 76, 78 becoming tied together, as collar C and drill bit DB are both relatively short in length and light in weight and once assembled can later be handled as a unit, i.e. once assembled they need never be taken apart. Of course, the drill bit DB could be constructed to include a non-threaded pin, like pin 16of length L, and the collar constructed to in- :clude two non-threaded box ends 18".

Further modified forms of collars according to the in vention included a collar having a threaded pin and nonthreaded box for engagement with a non-threaded pin, and a collar having a non-threaded pin and a threaded box for connection to a threaded pin.

Referring now to FIG. 9, this figure shows another modified form of drill pipe involving a modified form of pin and box construction, designated 80 and 82, respectively. Pin 80 is provided with a pair of diametrically opposed, inwardly tapering openings 84, 86 that register with complementary openings 80, 90 extending through the side wall of box 82. Pin 80 and the box opening possess the same degree of taper and preferably the outside dimension of pin 80 is such that the pin 80 must be driven slightly into the box opening in order to align openings 84, 86 with openings 80, 90, respectively, in the axial direction. This assures an extremely tight fit between the outer surface of pin 80 and the inner surface of the box opening, and makes possible the elimination of the shoulders employed with the cylindrical pin and box construction shown in FIGS. 1-8, for example. The compressive stresses are carried at the joints by the complementary tapered surfaces.

The coupling assembly 20, comprising cones 42, 44 and pin 46 is employed in a joint involving pin 80 and box 82 in the same manner as described above in connection with FIG. 2.

According to the invention, the length of drill pipe 92, shown in FIG. 9, is formed by swage forming the pin 80 out of one end portion of an initially cylindrical piece of drill pipe, and swage forming the box 82 out of the other end portion thereof. While possessing the same advantages of the drill pipe shown in FIGS. 4 and 5 as to simplicity and ease in joint assembly and disassembly, this form of the invention further possesses the advantages of involving no welded parts nor shoulders.

FIGS. 11-13 relate to still another form of nonthreaded tool joint according to the present invention, and the drill pipe involved therein.

Referring first to FIG. 11, the pipe length L shown thereby is closely similar to the form illustrated by FIG. 5. Such length L comprises a tubular body portion 68, a box joint component 18" welded to one end of such body portion 68, and a pin joint component 16" welded to the opposite end of such body portion 68.

With respect to its joint forming features, the box 18" is essentially identical to boxes 18, 18 shown by FIGS. 4 and 5, for example. It includes a terminal surface 32", annular wall means forming an axially extending, generally cylindrical socket or box opening, a pair of diametrically opposed, inwardly tapering openings 34", 36" extending laterally through said wall means, and wrenchreceiving recesses 60", 62".

Pin 16" is quite similar to pins 16, 16 in FIGS. 4 and 5. It includes an external shoulder 30" against which the terminal surface 32" of the next drilling shaft component abuts, a terminal surface 28 of its own, annular side wall means forming a central passageway in the pin 16", constituting a reduced diameter end portion of the drilling fluid passageway in the pipe L", and a pair of diametrically opposed, inwardly tapering openings 38", 40" extending laterally through annular wall means. However, in this form pin 16" also includes a transverse support wall or member 94. The support member 94 is shown to be cast integral with the annular side wall means of pin 16", but it could be separately formed and then welded into place. In any event, it is rigidly attached to the side wall means of pin 16".

Support member 94 extends longitudinally through the pin portion of the drilling fluid passageway and divides same into two parallel, substantially D-shaped paths (FIG. 13). The medial plane of member 94 coincides with the longitudinal center line axis of pipe L", and such plane is generally perpendicularly related to the center line axes of the tapered openings 38", 40". Member 94 is relatively thick and is provided with an opening 96 (preferably cylindrical in shape), disposed between and generally in line with the tapered openings 38", 40".

As clearly shown by FIGS. 12 and 13, the plug elements 98, are substantially longer than plug elements 42, 44, and are of a different form. They each include an inwardly tapering, preferably frusto-conical outboard portion (102, 104) and a substantially straight, preferably cylindrical inboard portion (106, 108). As in the earlier joint forms, the outboard portions 102, 104 of the plug elements 98, 100 fit snugly into the bores formed by the complementary openings in the concentrically related side wall means of the pin and box joint components. The inboard portion 108 of plug element 98 extends part way into the opening 96, from its side of member 94, and the inboard portion 108 of plug element-100 extends part way into opening 96 from its side of member 94. The inboard portions 106, 108 of plug elements 98, 100 are rather snugly received in the opening 96. Thus, the plug elements 98, 100 are in effect supported at both of their ends by the pin 16", the outboard ends thereof by the side wall means of the plug and the inboard ends by the support member 94.

The head portion 58 of the coupling bolt 46 is countersunk into one of the plug elements (plug element 100, for example), as in the other forms of the invention, and the threaded portion 54 of such bolt 46 is threaded into an internally threaded bore formed in the other plug element (plug element 98 in FIGS. 12 and 13), also as in the other forms. Thus, through the inboard portions 106, 108 of the plug elements 98, 100, the support member also supports the central portion of the coupling bolt 46, and substantially prevents it from deflecting or bending.

The plug elements 98, 100 are of such a length relative to the pin 16" that their respective inner ends 110, 112 never abut. A gap Z (FIG. 12), the size of which; is dependent on the amount of wear experienced by plug elements 98, 100, and the bores in which they are situated, always exists between the end surfaces 110,, 112 of the plug elements 98, 100.

The advantage of this latter form of tool joint, involving plug elements which are supported at both of their ends by the pin component 16" of the joint, is that it is capable of withstanding high torque forces without distortion or destruction of the coupling assembly. The plug elements 98, 100 are securely held against lateral turning in their bores, and the coupling bolt 48 is restrained against bending under the influence of high torque and/or tension forces to which the joint is subjected.

Although the drill pipe and drill pipe joint construction presented by the invention has a particular advantageous application in connection with raised joint operations, wherein the high torque condition at the joints of the drill stem practically prohibits the use of threaded joint, such joint construction constitutes an improvement in drilling shafts in general and the principles herein disclosed have application in all types of drilling or boring operations.

From the foregoing, further variations, modifications, adaptations, and usages of drill pipe and drill pipe joints will be apparent within the scope of the following claims.

What is claimed is:

1. A slip joint construction comprising concentrically related, separable, first and second, tubular, joint forming members, said first joint forming member including side wall means forming an axially extending socket opening sized to snugly accommodate the second joint forming member, with at least one pair of opposed, inwardly tapering openings extending laterally through said side wall means, and said second joint forming member including side wall means forming an axially extending interior passageway, with at least one pair of opposed, inwardly tapering openings extending laterally through said side wall means, and being registerable with the inwardly tapering openings in the side wall means of the first joint forming member, when said second joint forming member is engaged in the socket opening of said first joint forming member, to form a pair of opposed, in-

wardly tapering bore's, and a transversesnpport member spanning the interior pasa-geway in said second joint forming member, between'the tapered openings in the side wall means thereof, said support member being rigidly attached to the side wall means of said second joint forming member, and having an opening therein that is generally aligned with the tapered openings; and coupling means comprising a pair of plug elements having tapered outboard portions sized to snugly fit Within the tapered bores, and inboard portions insertable from opposite directions into the opening in said support member, to be engaged thereby, with said support member serving to substantially prevent sideways movement ofthe inboard end portions of said plug elements, and bolt means detachably connectable to said plug elements for pulling them together, and the tapered outboard portions thereof into tight engagement with the side surfaces of the tapered bores.

2. A slip joint construction comprising concentrically related, separable, first and second, tubular, joint forrning members, said first joint forming member including side wall means forming an axially extending socket opening sized to snugly accommodate the second joint forming member, with at least one pair of opposed, inwardly tapering, frustro-conical openings extending laterally through said side wall means, and said second joint forming member including side wall means forming an axially extending interior passageway, with at least one pair of opposed, inwardly tapering, frustro-conical openings extending laterally through said side wall means, and being registerable with the frustro-conical openings in the side wall means of the first joint forming member, when said second joint forming member is engaged in the socket opening of said first joint forming member, to form a pair of opposed, inwardly tapering, frustro-conical bores, and a transverse support member extending across the open interior of said second joint forming member at a location therein between the frustro-conical openings in the side wall means of said second joint forming member, said support member being rigidly attached to the side wall means of said second joint forming member, and having a generally cylindrical opening therein that is general-1y aligned with the frustro-conical openings; and coupling means comprising a pair of plug elements having inwardly tapering, frustro-conical outboard portions sized to snugly fit within the frustro-conical bores, and generally cylindrical inboard portions insertable from opposite directions into, and sized to snugly fit into, the generally cylindrical opening in' said support member, said support member serving to substantially prevent sideways movement of the inboard end portions of said plug elements, and a bolt having an enlarged head at one end and a threaded portion at the other end, with one of said plug elements having'an elongated opening extending axially therethrough to accommodate the shank of said bolt, and the other having an internally threaded, elongated opening therein for receiving the threaded portion of said bolt, said bolt serving when tightened to draw the plug elements together, and the outboard portions thereof into tight engagement with the side surfaces of such bores. 3. In a sectional, high torque drilling shaft, separable, first and second tubular driling shaft elements, each formed to include a central drilling fluid passageway, and a slip-joint connection between said elements, said joint comprising:

-(a) a tubular box at an end of the first drilling shaft element, said box including annular side wall means forming an axial-1y extending bo-x opening, constituting an end portion of the drilling fluid passageway in said first drilling shaft element, with at least one pair of opposed, inwardly tapering openings extending laterally through said side wall means;

-(b) a tubular pin at an end of the second drilling shaft element, insertable into said box opening, said pin. including annular 'side' wall'means forming a interior passageway in the .pin that constitutes a reduced diameter end portion of the drilling fluid passageway in said second drilling shaft element, with at least one pair of opposed, inwardly tapering openings extending laterally through said side wall means and being registerable with the said inwardly taperingopenings of said box, when the pin is in the box opening, to form a pair of opposed, -inwardly tapering bores, and a transverse support member extending across the open interior of said pin, inbetween the inwardly tapering openings, said support member being rigidly attached to the side wall means of said pin, and'having an opening therein that is generally aligned with the inwardly tapering openings; and

(c) a coupling assembly comprising a pair of elongated plug elements insertable into said inwardly tapering bores, and each being of one-piece form, and each having an inwardly tapering outboard portion of like taper as its bore, and an inboard portion shaped to snugly fit part way into the opening in said transverse support member, and bolt means detachably connectable to said plug elements for pulling them together and the outboard portions into tight engagement with the side surfaces of the bores.

4. A slip-joint according to claim 3, wherein the pin inludes an external shoulder in abutting engagement with the terminal of said box.

5. A slip-joint between first and second tubular, drilling shaft components, each formed to include a central drilling fluid passageway, said joint comprising:

(a) a tubular box at an end of the first tubular drilling shaft component, said box including annular side wall means forming an axially elongated box opening constituting an end portion of the drilling fluid passageway in said first drilling shaft component, with at least one pair of diametrically opposed, inwardly tapering openings extending laterally through said side wall means;

(b) a tubular pin at an end of a second tubular drilling shaft component, insertable into and snugly engageably by said box opening, said pin including annular side wall means forming a central passageway in the pin constituting the end portion of the drilling fluid pasageway in said second drilling shaft component, with at least one pair of diametrically opposed, inwardly tapering openings extending laterally through said side wall means, and being registerable with the said inwardly tapering openings of the box when the pin is in the box, so as to form a pair of diametrically opposed, inwardly tapering bores, and a transverse support member extending transversely across the open interior of the pin, inbetween the inwardly tapering openings, said support member being rigidly attached to the side wall means of said pin, and having an opening therein that is generally aligned with said inwardly tapering openings; and

(c) a coupling assembly comprising a pair of elongated plug elements having tapered out-board portions of like taper as said bores, and sized to snugly fit within said bores, and an inboard portion shaped and sized to snugly fit within about a half or less of the opening in said transverse support member, and a bolt having an enlarged head at one end and a threaded portion at the other end, with one of said plug elements having an elongated opening extending axially therethrough to accommodate the shank of said bolt, and the other having an internally threaded, elongated opening therein for receiving the threaded portion of said bolt, said bolt serving when tightened to draw the plug elements together, and the outboard portion thereof into tight engagement with the side surfaces of such bores.

6. A slip-joint according to claim 5, wherein the pin includes an external shoulder in abutting engagement with the terminal of said box.

References Cited by the Examiner 5 1 994 791 UNITED STATES PATENTS 2,092,372

1/1897 Doyle 285191 2,872,227 8/1902 Merrie et al. 2'85191 6/ 1966 Winberg et al. 287-119 FOREIGN PATENTS References Cited by the Applicant UNITED STATES PATENTS Wachs.

FOREIGN PATENTS Canada.

CARL W. TOMLIN, Primary Examiner.

3/1913 Great Britain.

THOMAS P. CALLAGHAN, Examiner.

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Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3383124 *Apr 28, 1966May 14, 1968Ingersoll Rand CoCoupling for drill rods
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Classifications
U.S. Classification403/379.4, 285/404
International ClassificationE21B17/02, E21B17/046
Cooperative ClassificationE21B17/046
European ClassificationE21B17/046