DRILLING TOOL AND METHOD FOR PRODUCING A BORE IN THE GROUND

Abstract

The invention relates to a drilling tool for producing a bore in the ground, comprising a rotatably drivable basic body, a removal means at a lower end of the basic body for removing soil material, and at least one adjustable removal element, which is adjustable between a radially inner retraction position and a radially outer extension position in which the removal element protrudes radially outwards relative to the basic body in order to widen a bore diameter. According to the invention it is provided that for adjusting the removal element, an adjustment mechanism with a rotary member is provided, which is rotatable on the basic body about the drilling axis between a first rotary position and second rotary position, that at least one removal element is arranged on a pivot arm which is pivotable relative to the basic body between a first pivot position, in which the at least one removal element is in its retraction position, and a second pivot position, in which the at least one removal element is in its extension position, and that an actuating cam is provided on the rotary member and/or on the at least one pivot arm, by means of which actuating cam a rotary movement of the rotary member can be converted into a pivot movement of the at least one pivot arm.

Claims

1-12. (canceled)

13. Drilling tool for producing a bore in the ground, comprising a rotatably drivable basic body, a removal means at a lower end of the basic body for removing soil material, and at least one adjustable removal element which is adjustable between a radially internal retraction position and a radially external extension position in which the removal element protrudes radially outwards relative to the basic body to widen a bore diameter, wherein for adjusting the removal element there is provided an adjustment mechanism with a rotary member which is rotatable on the basic body about the drilling axis between a first rotary position and a second rotary position, wherein the at least one removal element is arranged on a pivot arm which, relative to the basic body, is pivotable between a first pivoting position, in which the at least one removal element is in its retraction position, and a second pivoting position, in which the at least one removal element is in its extension position, and there is provided on the rotary member and/or on the at least one pivot arm an actuating cam by which a rotary movement of the rotary member can be converted into a pivoting movement of the at least one pivot arm, wherein the basic body has a drum-shaped drilling case with at least one lower receiving opening, and the rotary member is configured as a rotary base for opening and closing the at least one receiving opening.

14. Drilling tool according to claim 13 wherein the at least one actuating cam is configured as a pin.

15. Drilling tool according to claim 14 wherein the actuating cam which is configured as a pin is attached to the rotary member, and on the at least one pivot arm there is formed a link hole in which the pin engages.

16. Drilling tool according to claim 13, wherein on the basic body there is arranged at least one pivot pin on which the at least one pivot arm is pivotably mounted.

17. Drilling tool according to claim 13, wherein two pivot arms with at least one removal element are provided in an opposing arrangement on the lower end of the basic body.

18. Drilling tool according to claim 13, wherein the removal means is arranged on the rotary base.

19. Drilling tool according to claim 13, wherein on a lower region of the drum-shaped drilling case there is arranged in a hinged manner a folding base on which the rotary base is rotatably mounted.

20. Drilling tool according to claim 13, wherein the at least one pivot pin is formed on the basic body as a stop for limiting the rotary movement of the rotary base.

21. Drilling tool according to claim 13, wherein a cutout for forming a passage region for removed soil material is formed on the at least one pivot arm.

22. Drilling tool according to claim 13, wherein the at least one removal element is in the retraction position if the rotary base is closing the at least one receiving opening on the drilling case, and the at least one removal element is in the radially projecting extension position if the rotary base is revealing the receiving opening.

23. Method for producing a bore in the ground, wherein a drilling tool according to claim 13 is used.

Description

[0026] The invention is described further below using a preferred exemplary embodiment, which is shown in the drawings. In the drawings show:

[0027] FIG. 1 a first side view of a drilling tool according to the invention;

[0028] FIG. 2 a second side view, rotated by 90 from the side view of FIG. 1, of the drilling tool of FIG. 1 with removal elements in the retraction position;

[0029] FIG. 3 a view from below of the drilling tool of FIGS. 1 and 2 with removal elements in the retraction position;

[0030] FIG. 4 a side view of the drilling tool corresponding to FIG. 2 with radially extended removal elements;

[0031] FIG. 5 a view of the drilling tool of FIG. 4 from below; and

[0032] FIG. 6 an exploded perspective view of the drilling tool according to FIGS. 1 to 5.

[0033] A drilling tool 10 according to the invention in the state with removal elements 30 in the retraction position is explained below in conjunction with FIGS. 1 to 3. In the exemplary embodiment shown, the drilling tool 10 is configured as a drill bucket with a basic body 12, which comprises a housing-like drum-shaped drilling case 14. In a cover region 15 of the basic body 12, there are positioned, in a manner known per se, a connecting device 16 for releasably attaching drilling rods and an unlocking device 17. The unlocking device 17 is used to unlock and open a folding base 24, which is mounted on the underside of the drum-shaped drilling case 14, so as to be swung open via a hinged joint 26.

[0034] The mechanics for unlocking and locking the folding base 24 are known in principle and are not explained in more detail below.

[0035] On the folding base 24 on the underside of the basic body 12, a plate-shaped rotary member 40 is mounted rotatably about a central drilling axis between a first rotary position and a second rotary position. In FIGS. 1 to 3, the plate-shaped rotary member 40 is in the first rotary position, in which the adjustable removal elements 30 are in their radially retracted retraction position, as is shown clearly, in particular in FIGS. 2 and 3.

[0036] In the retraction position, the removal elements 30 in the form of cutting teeth are retracted radially inwards such that they do not protrude radially relative to the outer circumference of the drum-shaped drilling case 14.

[0037] For adjustment of the removal elements 30, they are arranged on two opposing pivot arms 50 in the drilling tool 10. Therefor, the pivot arms 50 are each mounted pivotably on a pivot pin 28 at their radially internal end. The pivot pin 28 is attached fixedly to the folding base 24 and extends parallel to the central drilling axis with a certain radial offset. Furthermore, the pivot arms 50 each have a link hole 52 which extends approximately in the radial direction and is substantially in the form of a slot in the exemplary embodiment shown. In each case two removal elements 30 at angles to one another are attached releasably to the radial outer end of the pivot arms 50.

[0038] The strip-shaped pivot arms 50 have a reinforced outer region and a thinner inner region, with a cutout 58 being formed in the inner region of the pivot arm 50. The cutout 58 allows passage of removed soil material below the pivot arm 50.

[0039] On the plate-shaped rotary member 40, which is in the form of a rotary base 42, there are arranged two removal means 20 with removal teeth 22, each on one holder 21. The removal teeth 22 in the form of cutting teeth are used to remove in-situ soil material during drilling. A pilot bit 19 for centering the drilling tool 10 during drilling is still arranged on the lower end of the drilling tool 10, in a manner known in principle.

[0040] The operating principle of the adjustment mechanism for displacing the removal elements 30 is explained in more detail in conjunction with FIGS. 4 to 6. The two pivot arms 50 are each mounted pivotably about pivot pins 28 which are attached fixedly to the folding base 24 and thus to the basic body 12 of the drilling tool 10. To pivot the pivot arms 50, two actuating cams 46 in the form of pins 48 are attached to the plate-shaped rotary member 40. Here, the pins 48 each engage in the associated link hole 52 in the respective pivot arm 50.

[0041] With reference to FIGS. 3 and 5, if the drilling tool 10 is driven in a drilling rotation direction, which is anticlockwise, the plate-shaped rotary member 40 with the removal means 20 attached thereto is adjusted counter to the drilling rotation direction out of the first rotary position according to FIG. 3 into a second rotary position according to FIG. 5. In this second rotary position, two receiving openings 25 in the folding base 24 are exposed, through which the removed soil material can pass into the receiving space in-side the drum-shaped drilling case 14. The rotary member 40 is mounted rotatably on the folding base 24 via a central rotational axis 44.

[0042] By means of the rotary movement counter to the drilling rotation direction, the actuating cams 46 in the form of pins 48 are also adjusted in the respective link hole 52 relative to the pivot arms 50 mounted on the folding base 24. As a result of this forced relative movement, the pivot arms 50 with the removal elements 30 attached thereto are adjusted from their radially retracted retraction position according to FIG. 3 into their radially extended extension position according to FIG. 5. In this extension position, the removal elements 30 protrude radially outwards relative to the outer circumference of the drum-shaped drilling case 14, so that the removal elements 30 effect an enlargement of the drilling diameter. The enlargement of the drilling diameter can there be set such that soil material below a supporting pipe (not shown) is removed, so that the supporting pipe can be fed into the borehole in a simplified manner.

[0043] When a drilling step is finished, for instance when the receiving space in the drilling case 14 is sufficiently filled with removed soil material, the rotary member 40 in the form of a rotary base 42 can be rotated back again into the first rotary position according to FIG. 3 by rotating the drilling tool 10 backwards counter to the drilling direction in a short-time, that is, clockwise with reference to FIGS. 3 and 5. In the process, the receiving openings 25 are closed at the bottom, so that no soil material can fall downwards out of the receiving space when the drilling tool 10 is pulled out of the borehole.

[0044] At the same time as the receiving openings 25 are being closed, the rotation of the rotary base 42 back into the first rotary position causes the pivot arms 50 with the removal elements 30 to pivot back into their retraction position according to FIG. 3. In this retracted position, the drilling tool 10 can problem-free be pulled axially through the supporting pipe positioned from above.