EP0458289B1 - Connection for drill pipes or the like - Google Patents

Abstract

In a detachable connection for drill pipes and other objects which can be used in the sinking of boreholes, a sleeve part (21) has in the interior radially directed projections, the undersides of which at least partly form engagement surfaces for bearing surfaces on an insertion part (11) for transmitting axial tensile forces. The insertion part (11) is provided on the outside with radially directed locking pieces which in each case form the bearing surfaces with at least part of their front sides. At least one supporting surface for seating the insertion part (11) for transmitting axial compressive forces is located on the sleeve part (21). Furthermore, there are push-in parts via which a torque can be transmitted. <IMAGE>

Description

The invention relates to a detachable connection for drill pipes or other objects that can be used when drilling holes, according to the preamble of claims 1 and 6.

In a known threadless coupling of drill pipe parts (DE-C-9471782), the sleeve part has a blind hole with a smooth wall, into which a cylindrical pin protruding from the plug-in part can be inserted. In addition, there are two diametrically opposed cams on the plug-in part, which can enter into recesses at the end of the sleeve part when the coupling is assembled. A torque can then be transmitted via them. The pin of the male part has an annular groove near its end, in which hemispherical approaches of screws can engage after the parts have been joined, which are screwed into radial bores of the socket part. The screws can only absorb tensile forces, if at all, to an extremely small extent. The male part and the female part both have a closed cross section. An internal axial passage is not available with such a coupling.

In another known drill pipe coupling (DE-A-1229932), the sleeve part is designed on the inside as a hexagon. The plug-in part has a pin with a corresponding external hexagon, which should fit into the socket part with tight play. The pin has an annular groove between its ends. In the socket part there are two parallel bores into which a U-shaped bracket can be inserted, the legs of which engage at opposite points in the ring groove of the pin when the insert part is inserted into the socket part up to a stop. It is only a matter of securing the parts against axial relative movement and preventing them from separating.

Finally, from FR-A-961165 a detachable connection for drill pipes is known, which corresponds to the type specified. The pipes are coupled by inserting an insertion part into a socket part and by rotating one part relative to the other part. However, the known connection is not reliable, because with it the assembled parts can still move relative to one another depending on the action of external forces and can take uncontrolled intermediate positions, so that the risk of unintentional unlocking is not excluded. In addition, the connection is not suitable for the transmission of higher torques.

The object of the invention is to provide a threadless, releasable connection of the type specified, which allows a safe transmission of even high torques in both directions, with full transmission of axial pressure and tensile forces, without being undefined when changing the direction of force or rotation Relative positions of the parts can occur and without the benefit of a large internal passage in each other parts to be connected must be dispensed with. The invention also aims for advantageous designs of the connection or its parts in detail. Further problems connected with all of this, with which the invention is concerned, result from the respective explanation of the indicated solution.

The invention is characterized by the features specified in claims 1 and 6.

This creates a connection for drill pipes or other parts that can be used when drilling bores, in particular so-called displacement screws and similar tools, which is characterized by a number of essential advantages. The connection, which is easy and quick to produce, is practically free of play in the operating state, so that no undesirable conditions can occur even when there are changes in force or torque. The connection is such that it can be designed without difficulty for the absorption of high loads, in particular for the transmission of high torques in both directions. All of this is achieved without blocking the interior of the parts, so that the connection is particularly suitable and advantageous even in those cases in which a drill string, a tool or an assembly used in drilling work is to be flowed through by a medium. It can e.g. is a drilling fluid or concrete that is to be routed to the bottom of a hole, such as in pile foundations.

The projections located in the interior of the sleeve part can in particular be formed like strips and with their sides form the counter surfaces for the torque transmission surfaces of the insert part. In another embodiment, inside the sleeve part, apart from the projections, are distributed radially over the inner circumference protruding parts are arranged, which form with their sides the counter surfaces for the torque transmission surfaces of the male part.

There are also various options for the design and arrangement of the slide-in parts. They can have the form of longitudinal bolts which can be inserted into recesses on the outer circumference of the insert part and in passages in the socket part. The number of these longitudinal bolts can be chosen depending on the requirements, in particular the size of the torque that is to be transmitted by them. If there are applications in which essentially only a not very large torque is to be transmitted in one direction, an arrangement of two longitudinal bolts can be sufficient and expedient, in particular at diametrically opposite points. The longitudinal bolts can advantageously be releasably attached to the insert, e.g. by clamping pins or the like.

In the embodiment of the invention, in which pins are provided as insertion parts on the outer circumference of the plug-in part, which can be inserted into recesses on the outer circumference of the socket part, the design can in particular be such that the pins are displaceably guided with limited travel and are under the force of compression springs .

The connection is also particularly suitable for double-walled parts in which, in addition to a central cavity, there is an annular cavity which is sealed off from this. An inner tube then extends into the socket part and into the insert part. When the connection is joined, their ends lie against each other, be it blunt or be it with a certain overlap, advantageously at least one seal being present.

Fig. 1

eine Ausführung eines Einsteckteiles teils in Ansicht, teils im Längsschnitt,

Fig. 2

eine Stirnansicht zu Figur 1,

Fig. 3

eine zum Einsteckteil nach den Figuren 1 und 2 passende Ausführung eines Muffenteiles im Längsschnitt,

Fig. 4

eine Stirnansicht zu Fig. 3,

Fig. 5

reine Einheit eines Bohrrohres (Bohrgestängeteiles), im Bereich der Enden teilweise im Schnitt,

Fig. 6

eine Verbindung zwischen einem Bohrrohr und einer Verdrängerschnecke, teilweise im Schnitt,

Fig. 7

einen Einsteckteil anderer Ausführung, teils in Ansicht, teils im Schnitt,

Fig. 8

einen Muffenteil anderer Ausführung, teils in Ansicht, teils im Schnitt,

Fig. 9

die zusammengesetzte Verbindung mit den Teilen nach den Figuren 7 und 8, teils in Ansicht, teils im Schnitt,

Fig. 10

einen Schnitt nach der Linie X-X in Fig. 9,

Fig. 11

eine weitere Ausführung eines Einsteckteiles, teils in Ansicht, teils im Schnitt,

Fig. 12

eine weitere Ausführung eines Muffenteiles, teils in Ansicht, teils im Schnitt,

Fig. 13

die zusammengesetzte Verbindung mit den Teilen nach den Figuren 11 und 12, teils in Ansicht, teils im Schnitt und

Fig. 14

einen Vorgang beim Lösen der Verbindung nach Figur 13.

Further details, features and advantages of the invention result from the following explanation of exemplary embodiments, from the associated drawing and from the claims. Show it:

Fig. 1

an embodiment of an insert part partly in view, partly in longitudinal section,

Fig. 2

2 shows a front view of FIG. 1,

Fig. 3

1 a design of a socket part in longitudinal section that matches the plug-in part according to FIGS.

Fig. 4

3 shows an end view of FIG. 3,

Fig. 5

pure unit of a drill pipe (drill pipe part), partially in the area of the ends,

Fig. 6

a connection between a drill pipe and a displacement screw, partly in section,

Fig. 7

a plug-in part of another design, partly in view, partly in section,

Fig. 8

a sleeve part of another design, partly in view, partly in section,

Fig. 9

the assembled connection with the parts according to Figures 7 and 8, partly in view, partly in section,

Fig. 10

a section along the line XX in Fig. 9,

Fig. 11

another version of a plug-in part, partly in view, partly in section,

Fig. 12

another version of a socket part, partly in view, partly in section,

Fig. 13

the composite connection with the parts of Figures 11 and 12, partly in view, partly in section and

Fig. 14

a process when loosening the connection of Figure 13.

1 to 4 show an advantageous embodiment of the connection with the insert part 11 and the socket part 21. Both parts each have a free axial passage D of relatively large diameter, which is located in the subsequent part, e.g. Drill pipe, tool or the like. Can continue. The sleeve part 21 is provided on the inside of its wall with projections 22 which are regularly distributed over the circumference and extend in the direction of surface lines, between which corresponding passages 23 remain. The undersides of the projections 22 form flat engagement surfaces 24 for contact surfaces 14 provided on the plug-in part 11.

These contact surfaces 14 are formed by the front sides of locking pieces 13, which are regularly distributed over the outer circumference on the insertion part 11 and are directed radially. The extent a of the locking pieces 13 in the circumferential direction is somewhat less than the circumferential dimension b of the passages 23 in the sleeve part 21.

In this embodiment, the socket part 21 has a support surface 25 on the end face, against which a support 15 can come into contact with the insert part 11 when the connection is made.

On the plug-in part 11 radially projecting lugs 12 are provided in addition to the locking pieces 13, which are expediently distributed in a regular arrangement over the outer circumference of the plug-in part 11, advantageously such that their number is equal to the number of locking pieces 13. As such, the lugs 12 can pass directly into the locking pieces 13. However, it is advantageous to leave a distance between the two, as can be seen from FIG. 1.

A side surface 17 of the lugs 12 is aligned with a side surface 18 of the locking pieces 13. The other side surfaces 16 of the lugs 12 serve as torque transmission surfaces when the connection is joined. They then come to rest against counter surfaces 26 in the interior of the sleeve part 21, which are formed in the embodiment shown from side surfaces of the projections 22.

The connection also includes elements referred to as insertion parts which, after the sleeve part 21 and the plug-in part 11 have been joined together, are in positive engagement with the latter and run parallel to the longitudinal central axis of the connection. The arrangement and design is such that a torque can be transmitted via the insert parts. There are various options for individual training.

For the embodiment shown in FIGS. 1 to 4 and also also in FIGS. 5 and 6, insert parts are used longitudinal bars 31 are advantageously considered, which can be inserted into recesses 19 on the outer circumference of the plug-in part 11 and into free passages 23 at the relevant points of the socket part 21. The insertion part 11 is designed so that the longitudinal bars 31 can be inserted in the direction of surface lines into the recesses 19 and the passages 23 aligned therewith.

FIG. 5 shows a drill pipe 1 which is designed as a socket part 21 at one end and as a plug-in part 11 at the other end. Any number of such drill pipes can then be assembled into a strand by means of the connecting parts explained.

In FIG. 6, a drill string part 2 is connected to a displacement screw 3 with the aid of the connection, which is shown in the assembled state, on one side in view, on the other side in section.

The connection is made in the illustrated embodiment as follows. The insertion part 11 is inserted axially into the sleeve part 21 such that the locking pieces 13 and also the lugs 12 can be pushed through the passages 23. The length of the passages 23 and the locations at which the locking pieces 13 are coordinated so that the locking pieces 13 at the inner end of the passages 23 can emerge from them before the support 15 on the plug-in part 11 is fully in contact with the support surface 25 of the sleeve part 21 comes. The insertion part 11 is then rotated relative to the sleeve part 21 about its axis in such a way that the contact surfaces 14 on the locking pieces 13 slide under the ends of the projections 22 and thus bear against the engagement surfaces 14. The torque transmission surfaces 16 also come at the lugs 12 of the Push-in part 11 for contacting the counter surfaces 26 of the projections 23 of the socket part 21. In this state of connection, the surfaces 14 and 24 can transmit an axial tensile force and the surfaces 15 and 25 can transmit an axial pressure force between the parts connected to one another. In addition, the transmission of a torque in one direction of rotation is possible via the surfaces 16 and 26. Torque transmission in the other direction of rotation is ensured by the longitudinal bolts 30 (FIG. 6) which are inserted into the recesses 19 and passages 23 aligned with them. The longitudinal bolts 30 or the like by a split pin or the like. be fixed on the plug-in part, as indicated at point 32.

Another embodiment of the connection is shown in FIGS. 7 to 9, which differs in some details from that according to FIGS. 1 to 4, but to which the statements made there also apply in principle. One difference is that a drill pipe or similar rod part with a single passage D is shown in FIGS. 1 to 6. In the embodiment according to FIGS. 7 to 9, the use of the connection in a so-called double wall linkage is shown. Both in the plug-in part 41 and in the socket part 51, in addition to a large inner passage D1, there is also an annular passage D2 surrounding the latter, which is achieved in that an inner tube 7 or 8 is inserted into an outer tube 5 or 6, respectively. When joining the connection, a bell-shaped end 7a of the inner tube 7 engages over the end of the inner tube 8, a seal 9 additionally ensuring that the two spaces D1 and D2 remain separate from one another.

In this embodiment as well, the insertion part 41 has radially projecting projections 42 and locking pieces 43, the extent of which in the circumferential direction is the same here Size. A side surface 47 of the lugs 42 is aligned with a side surface 48 of the locking pieces 43. The other side surfaces 46 of the lugs 42 serve as torque transmission surfaces.

In the interior of the sleeve part 51 there are projections 52 and parts 57 which protrude radially therefrom. Side surfaces 56 of the latter form the counter surfaces for the torque transmission surfaces 46 of the plug-in part 41. Passages 53 are left between the projections 52 and the parts 57, through which the lugs 42 and locking pieces 43 can move when the plug-in part 41 into the socket part 51 is inserted. When the two parts are subsequently rotated relative to one another, the locking pieces 43 engage with their contact surfaces 44 under the projections 52 and lie against the engagement surfaces 54 formed by their undersides, as a result of which perfect transmission of tensile force is ensured.

In the assembled state of the connection, which is shown in FIGS. 9 and 10, the insertion part 41 lies with a shoulder-like support 45 on a support surface 55 of the socket part 51, so that the transmission of pressure forces is also ensured.

Similar to the embodiment according to FIGS. 1 to 6, longitudinal bolts 31 are also present as further torque-transmitting elements, which can be inserted into recesses 49 on the outer circumference of the insert part 41 and into free areas of the passages 53 in the socket part 51 that are aligned with the recesses. Such a longitudinal bar 31 is only shown in FIG. 7. At least two longitudinal bars are advantageously provided at mutually opposite locations. Their number can also be larger depending on the requirements.

In the embodiment according to FIGS. 11 to 13, the sleeve part 71 in turn has inner projections 72 distributed over the circumference with passages 73 in between. On the insertion part 61 there are radially projecting locking pieces 63 which move through the passages 73 on the socket part 71 when the parts are joined and, after the relative rotation of the two parts, engage under the projections 72. The contact surfaces 64 come into contact with the rear engagement surfaces 74 of the projections 72. This ensures that the tensile force is transmitted correctly. Pressure forces are transmitted from the support 65 of the insert 61 to the support surface 75 of the sleeve part 71. In addition, a shoulder 66 can also rest on the insertion part 61 on the front sides 76 of the projections 72.

In this embodiment, insert parts in the form of pins 67 on the insert part 61, which can engage in through bores 77 on the socket part 71, serve to transmit torques in both directions, as can be seen in FIG. 13. The number of pins can be selected depending on the loads to be absorbed. The pins 67 are displaceable in guide bores and are under the force of compression springs 68. The extension path is in each case limited by a collar 69 on the pin 67. When inserting insert 61 and sleeve part 71 by pushing one into the other, pins 67 first sit on support surface 75 of sleeve part 71. They then slide along this during the subsequent relative rotation of the two parts until, at the end of this movement, they snap into the bores 77 arranged at the corresponding points.

When the connection is released, the pins 67 are pushed back so far against the force of the compression springs 68 that the plug-in part 61 can be rotated about its axis relative to the socket part 71, whereby the ends of the pins 67 slide on the support surface 75. The parts are then moved axially apart, whereby the connection is separated. A counter-holder 78 with lugs 79 fitting into the bores 77 can serve to push back the pins 67. The counter-holder is in particular ring-shaped, as shown in FIG. 14, so that it can be displaced on the cylindrical outside of the sleeve part 71. It can be divided so that it can be placed around the sleeve part for use.

Also in the embodiment according to FIGS. 11 to 13, the insertion part 61 has an inner tube 7 and the socket part 71 has an inner tube 8, so that two passages D1 and D2 are present, as can be the case with a double linkage.

All the features mentioned in the above description or shown in the drawing, if the known prior art permits, should be regarded as falling within the scope of the invention, either alone or in combinations.

Claims (8)

1. A releasable connection with a sleeve part (21, 51) and an insertion part (11, 41) for drill-pipes or other objects for use when sinking bore holes,

   - the sleeve part (21, 51) having a free axial passage (D, D1) and also having radially oriented projections (22, 52) distributed over the inner periphery of its wall, with axial gaps (23, 53) between the said projections;

   - the lower surfaces of at least a part of the projections (22, 52) forming engagement surfaces (24, 54) for contact surfaces (14, 44) on the insertion part (11, 41) for transmission of axial tensile forces;

   - the insertion part (11, 41) having a free axial passage (D, D1) and also having radially oriented locking parts (13, 43) distributed over its outer periphery, the extension (a) of the said locking parts in the peripheral direction being slightly less than the peripheral dimension (b) of the gaps (23, 53) in the sleeve part (21, 51), and by means of at least a part of their front surfaces the said locking parts respectively form the contact surfaces (14, 44) associated with the engagement surfaces (24, 54) of the projections (22, 52) on the sleeve part (21, 51);

   - the sleeve part (21, 51) having at least one supporting surface (25, 55) for a support (15, 45) on the insertion part (11, 41) for transmission of axial compressive forces;

   characterised in that

   - radially projecting shoulders (12, 42) with torque-transmitting surfaces (16, 46) are provided on the insertion part (11, 41) and are distributed over the outer periphery thereof, and are associated with opposite surfaces (26, 56) at the interior of the sleeve part (21, 51); and

   - slide-in parts (31; 67) are provided and after joining together of the sleeve part (21, 51) and the insertion part (11, 41) the said slide-in parts are in positive-locking engagement therewith, and extend parallel to the longitudinal central axis of the connection, in such a manner that torque can be transmitted thereby.
2. A connection in accordance with claim 1, characterised in that the projections (22) at the interior of the sleeve part (21) are formed to be strip-like, and the sides thereof form the opposite surfaces (26) to the torque-transmitting surfaces (16) on the insertion part (11).
3. A connection in accordance with claim 1, characterised in that in addition to the projections (52), radially projecting parts (57) are arranged at the interior of the sleeve part (51) and are distributed over the inner periphery thereof, and the sides of the said parts (57) form the opposite surfaces (56) to the torque-transmitting surfaces (46) on the insertion part (41).
4. A connection in accordance with one of claims 1 to 3, characterised in that longitudinal locking parts (31) are provided as slide-in parts, and can be inserted into recesses (49) on the outer periphery of the insertion part (11, 41) and into gaps (23, 53) in the sleeve part (21, 51).
5. A connection in accordance with claim 4, characterised in that the longitudinal locking parts (31) are releasably securable on the insertion part (11, 41).
6. A releasable connection with a sleeve part (71) and an insertion part (61) for drill-pipes or other objects for use when sinking bore holes,

   - the sleeve part (71) having a free axial passage (D, D1) and also having radially oriented projections (72) distributed over the inner periphery of its wall, with axial gaps (73) between the said projections;

   - the lower surfaces of at least a part of the projections (72) forming engagement surfaces (74) for contact surfaces (64) on the insertion part (61) for transmission of axial tensile forces;

   - the insertion part (61) having a free axial passage (D, D1) and also having radially oriented locking parts (63) distributed over its outer periphery, the extension (a) of the said locking parts in the peripheral direction being slightly less than the peripheral dimension (b) of the gaps (73) in the sleeve part (71), and by means of at least a part of their front surfaces the said locking parts respectively form the contact surfaces (64) associated with the engagement surfaces (74) of the projections (72) on the sleeve part (71);

   - the sleeve part (71) having at least one supporting surface (75) for a support (65) on the insertion part (61) for transmission of axial compressive forces;

   characterised in that
      - pegs (67) are provided on the outer periphery of the insertion part (61) as slide-in parts (67) which after joining together of the sleeve part (71) and the insertion part (61) are in positive-locking engagement therewith, and extend parallel to the longitudinal central axis of the connection, and torque can be transmitted thereby, and the said pegs (67) can be inserted into bore holes (77) or the like on the outer periphery of the sleeve part (71).
7. A connection in accordance with claim 6, characterised in that the pegs (67) are displaceably guided over a restricted path and are subject to the force of pressure springs (68).
8. A connection in accordance with one of claims 1 to 7, characterised in that a respective inner pipe (7 or 8) extends inside the sleeve part (51, 71) and the insertion part (41, 61), and when the connection is in operational state the inner pipes (7, 8) adjoin one another in a sealed manner.

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