CLAMPING HEAD ASSEMBLY FOR CLAMPING A DRILL PIPE ELEMENT

Abstract

The invention relates to a clamping head assembly for clamping a drill pipe element, comprising a clamping head base, at least one clamping jaws base body which is radially adjustable at the clamping head base between a clamping position and a releasing position relative to the drill pipe element, and at least one adapter element at the clamping jaws base body, wherein the adapter element is adapted to a shape of the drill pipe element to be clamped and is configured to abut and clamp the drill pipe element in the clamping position. According to the invention, it is provided that the adapter element is releasably arranged on the clamping jaws base body and can be locked by means of an actuatable locking device, and that the locking device comprises at least one latch element adjustable between a locking position, in which the adapter element is locked and secured to the clamping jaws base body, and a release position, in which the adapter element is released and removable from the clamping jaws base body.

Claims

1. A clamping head assembly for clamping a drill pipe element comprising a clamping head base, at least one clamping jaws base body which is radially adjustable at the clamping head base between a clamping position and a releasing position relative to the drill pipe element, and at least one adapter element on the clamping jaws base body, wherein the adapter element is adapted to a shape of the drill pipe element to be clamped and is configured to abut and clamp the drill pipe element in the clamping position, wherein the adapter element is releasably arranged on the clamping jaws base body and can be locked by means of an actuatable locking device, and the locking device comprises at least one latch element adjustable between a locking position, in which the adapter element is locked and secured to the clamping jaws base body, and a release position, in which the adapter element is released and removable from the clamping jaws base body.

2. The clamping head assembly according to claim 1, wherein the clamping head base is of substantially cylindrical or tubular design.

3. The clamping head assembly according to claim 1, wherein a plurality of clamping jaws base bodies are arranged to be distributed over a circumference of the drill pipe element to be clamped.

4. The clamping head assembly according to claim 1, wherein at least one latch element is biased and retained in the locking position by a biasing device.

5. The clamping head assembly according to claim 1, wherein the at least one latch element comprises an actuating portion for adjusting the latch element from the locking position to the release position.

6. The clamping head assembly according to claim 1, wherein the at least one latch element is mounted displaceably on or in a clamping jaws base body, and in the locking position, an actuating portion (44) of the latch element projects with respect to the clamping jaws base body.

7. The clamping head assembly according to claim 1, wherein the at least one clamping jaws base body is mounted to be axially displaceable, and a wedge gate valve mechanism is formed on the clamping head base, by means of which mechanism an axial movement of the at least one clamping jaws base body can be converted into a radial clamping movement.

8. The clamping head assembly according to claim 1, wherein at least one stop is arranged on the clamping head base, against which stop an actuating portion of the latch element is movable, wherein the latch element is adjustable from its locking position to the release position.

9. The clamping head assembly according to claim 1, wherein the adapter element comprises at least one retaining portion which projects into a recess in the clamping jaws base body, and the at least one retaining portion is configured to cooperate with the at least one latch element of the clamping jaws base body for at least positively securing the adapter element to the clamping jaws base body.

10. The clamping head assembly according to claim 9, wherein the retaining portion comprises a retaining pin on which a locking recess is formed, in which the latch element engages with a latch portion for positive locking in the locking position.

11. The clamping head assembly according to claim 10, wherein the latch element comprises a release portion which, in the release position, is arranged on the locking recess in such a way that the adapter element with the retaining portion is removable from the clamping jaws base body.

12. The clamping head assembly according to claim 1, wherein an adjusting device, in particular having at least one adjusting cylinder, is arranged, by means of which device the at least one clamping jaws base body is adjustable.

13. A drilling apparatus for making a borehole, in particular in a ground, comprising at least one drill pipe element, wherein a clamping head assembly according to claim 1 is provided.

Description

[0022] The invention is further described below with reference to preferred exemplary embodiments, which are shown schematically in the drawings. The drawings show in:

[0023] FIG. 1 a cross-sectional view through a clamping head assembly according to the invention;

[0024] FIG. 2 a perspective view of a clamping jaws base body with the adapter element being inserted in locking position;

[0025] FIG. 3 a perspective view of the adapter element with the associated latch element in the locking position without the clamping jaws base body;

[0026] FIG. 4 a perspective view of adapter element and latch element corresponding to in FIG. 3, but in a release position of the latch element; and

[0027] FIG. 5 a perspective view of the clamping jaws base body according to FIG. 2 when the adapter element is removed in the release position.

[0028] FIG. 1 schematically shows a clamping head assembly 10 according to the invention with a sleeve-shaped clamping head base 12. The clamping head assembly 10 can be firmly attached to a partially indicated rotary drive 80 and in particular to a rotationally driven output element 82 with a connection piece with an external thread 84. The clamping head base 12 can thus rotate with the output element 82 of the rotary drive 80. A drill pipe with a corresponding internal thread can be screwed on via the external thread 84 of the output element 82. The drill pipe is arranged inside the sleeve-shaped clamping head base 12 and is not shown in FIG. 1.

[0029] On the outside of the sleeve-shaped clamping head base 12, a clamping head carriage 14 is mounted axially displaceably. For axial displacement, an adjusting device 70 having one or more adjusting cylinders 72 can be arranged, as also shown schematically in FIG. 1. The adjusting device 70 can be fixedly attached to a base body (not shown), such as a drilling apparatus, and can be stationary relative to the rotating drive element 82. By means of the at least one adjusting cylinder 72, an actuator 74 can be displaced, which is connected to the axially movable clamping carriage 14 via pivot bearings 76. In this way, an axial actuating movement can be transmitted from the relatively fixed adjusting device 70 to the clamping carriage 14 rotating about a longitudinal and/or rotational axis at the clamping head base 12.

[0030] At a front side of the clamping carriage 14, one or more clamping jaws base bodies 20 can be connected to the clamping carriage 14 by means of an annular holder 22. The holder 22 can be configured in such a way that it creates an axially fixed connection with the at least one clamping jaws base body 20, but allows radial movement of the clamping jaws base body 20 with respect to the clamping head base 12 with respect to the longitudinal or rotational axis.

[0031] An outer side surface of the clamping jaws base body 20 is inclined or tapered so that it forms a wedge gate valve mechanism 18 with a corresponding inclined or conical guide element 17, which is fixedly attached to the outer side of the clamping head base 12. The wedge gate valve mechanism 18 is configured in such a way that during an axial advance movement of the clamping carriage 14, the clamping jaws base body 20 is adjusted not only axially but also in a defined manner in a radial direction, in particular radially inwards.

[0032] Plate-like adapter elements 30, preferably arc-shaped on their inner side and adapted to the drill pipe element to be clamped, are arranged on the clamping jaws base body 20 on the radial inner side. The adapter elements 30 extend through window-like passages 16 in the clamping head base 12 from the clamping jaws base body 20 attached to the radial outer side into the inner space of the sleeve-shaped clamping head base 12. The caused radial movement of the clamping jaws base bodies 20 with the adapter elements 30 attached thereto allows radial force-fit clamping of a cylindrical drill pipe element arranged in the clamping head base 12. By returning the clamping carriage 14 by means of the adjusting device 70, the clamping jaws base body 20 with the adapter element 30 is radially returned again, wherein the clamping of a drill pipe element is released.

[0033] In accordance with the invention, the adapter elements 30 are each releasably and replaceably retained on the clamping jaws base body 20 by means of a locking device 40, wherein the locking device 40 has a bolt-like latch element 42 arranged parallel to the longitudinal or rotational axis and having a pin-like actuating portion 44 which projects axially with respect to an end face of the associated clamping jaws base body 20.

[0034] To release the locking device 40, the clamping jaws base body 20 can be moved up to a forward end position at which the actuating portion 44 of the latch element 42 is pressed against an axial stop 60. The operation of the locking device 40 is described in greater detail below in conjunction with the further Figures.

[0035] FIG. 2 shows an enlarged view of a clamping jaws base body 20. The clamping jaws base body 20 has a recess 26 into which the adapter element 30 with a retaining portion 36 is fittingly inserted. FIG. 2 also shows that the adapter element 30 has an arcuate clamping surface 32 on its upper side, the contour of which is adapted to an outer contour of a cylindrical drill pipe element to be clamped.

[0036] The locking device 40 with a bolt-shaped latch element 42 is arranged inside the clamping jaws base body 20. The latch element 42 is displaceably mounted and retained in a receiving bore in the clamping jaws base body 20 via a screwed fastening plate 24, wherein a pin-like actuating portion 44 with a dome-shaped head projects in a defined manner from the latch element 42 out of the clamping jaws base body 20.

[0037] The design and operation of the locking device 40 are explained in greater detail in conjunction with the schematic illustrations of FIGS. 3 and 4. For reasons of clarity, only the adapter element 30 and the locking device 40 are shown, but not the surrounding clamping jaws base body 20.

[0038] FIG. 3 shows the locking device 40 in its locked position. The bolt-shaped latch element 42 is retained in the locking position by a biasing device 50, which can be configured as a helical spring 52 according to the exemplary embodiment shown. In the process, a latch portion 46 of the latch element 42 engages in an annular groove-shaped locking recess 38 of a retaining pin 37, which is formed on an underside of the retaining portion 36 of the adapter element 30. The retaining pin 37 is thereby received in a corresponding receiving bore within the clamping jaws base body 20. Thus, in this arrangement, the retaining pin 37 is retained positively by the latch portion 46 engaging in the locking recess 38. In this locking position, the front actuating portion 44 of the latch element 42 projects axially in a defined manner relative to the fastening plate 24 attached to the clamping jaws base body 20.

[0039] If the clamping jaws base body 20 is now moved axially against the stop 60 as shown in FIG. 1, the actuating portion 44 and thus the latch element 42 are pressed inwards into a release position, which is shown schematically in FIG. 4. During this actuating movement, the larger diameter latch portion 46 disengages from the locking recess 38. Further, as the latch element 42 is displaced into the area of the locking recess 38 on the retaining pin 37, a release portion 48 of the latch element 42 is pushed. The release portion 48 is smaller in diameter than the adjacent latch portion 46. The release portion 48 is configured in such a way that the retaining pin 37 is no longer positively blocked and the adapter element 30 can therefore be pulled upwards out of the recess 26 on the clamping jaws base body 20, as shown in FIG. 5. In this release position, a new adapter element 30 can then be inserted into the clamping jaws base body 20, which preferably has a different arc-shaped contour of the clamping surface 32.

[0040] After inserting the new adapter element 30, the clamping jaws base body 20 can be pushed away from the stop 60 again with the adjusting device 70 as shown in FIG. 1, wherein the bolt-shaped latch element 42 is adjusted. In the process, the latch element 42 is returned to the locking position by the biasing device 50 compressed in the release position by the helical spring 52. The latch element 42 returns again to the position according to FIG. 3.

[0041] FIG. 5 schematically shows the removal of the adapter element 30 from the approximately rectangular recess 26 on the clamping jaws base body 20. It is further evident from FIG. 5 that in this release position according to FIG. 4, the latch element 42 is pressed with the actuating portion 44 into the receiving bore in the clamping jaws base body 20, wherein the actuating portion 44 does not project relative to the face side of the clamping jaws base body 20 with the fastening plate 24.