Soil-displacement drill, method for converting a soil-displacement drill and method for forming a foundation pile

Abstract

Soil-displacement drill (1) for soil-displacing drilling in a surface (10) in order to form a foundation pile (2), comprising a drill pipe (3), a drill head (4) at an end of the drill pipe (3) with several flap leaves (5) which are pivotable between a closed position for closing off the end of the drill pipe (3) and an open position for making this end freely accessible and one or several closing elements (6) to keep these flap leaves (5) in their closed position and prevent pivoting of the flap leaves (5) which are configured to fail during drilling into the surface (10) in such a way that these closing elements (6) do not impede pivoting of the flap leaves (5). In addition, the present invention relates to an assembly of a drill head (4) and one or several closing elements (6) for such a soil-displacement drill (1), a method for soil-displacing drilling and a method for converting a soil-displacement drill (1) to form such a soil-displacement drill (1).

Claims

1. Soil-displacement drill for soil-displacing drilling in a surface in order to form a foundation pile, comprising: a drill pipe; and a soil-displacement assembly of a drill head, wherein the drill head comprises several flap leaves which are arranged so as to be able to pivot between a closed position and an open position, and wherein one or several closing elements are attachable to the outside of at least two flap leaves in order to keep these flap leaves in their closed position and to prevent the flap leaves from pivoting and are configured to fail during drilling of the soil-displacement drill into the surface in such a manner that these closing elements do not impede pivoting of the flap leaves, wherein the drill head of the assembly is attached to one end of the drill pipe and the flap leaves of the drill head are arranged for closing off the end of the drill pipe in the closed position and for at least partly making the end of the drill pipe freely accessible in the open position, wherein each closing element comprises one or several weakened sections in order to cause this closing element to fail more quickly during drilling, and wherein each closing element comprises one or several recesses to form the said weakened sections.

2. Soil-displacement drill according to claim 1, wherein the soil-displacement drill comprises only one said closing element which is configured to keep all flap leaves in their closed position.

3. Soil-displacement drill according to claim 2, wherein the closing element is at least partly annular.

4. Soil-displacement drill according to claim 1, wherein each closing element comprises one or several engagement elements in order for the surface to engage thereon while drilling the soil-displacement drill into the surface in order to accelerate the failing of this closing element.

5. Soil-displacement drill according to claim 4, wherein each closing element comprises an annular base body and in that the one or several said engagement elements are raised with respect to this base body and delimit the one or several recesses.

6. Soil-displacement drill according to claim 5, wherein the drill tip comprises a cylindrical base body, over which the annular part of the closing element is arrangeable in order to attach the closing element to the flap leaves.

7. Soil-displacement drill according to claim 1, wherein the soil-displacement drill comprises a drill tip which is attachable to or forms part of the flap leaves, away from the end of the drill pipe.

8. Soil-displacement drill according to claim 1, wherein each flap leaf comprises a drill tip part, wherein these drill tip parts together form the drill tip in the closed position of the flap leaves.

9. Soil-displacement drill for soil-displacing drilling in a surface in order to form a foundation pile, comprising: a drill pipe; and a soil-displacement assembly of a drill head, wherein the drill head comprises several flap leaves which are arranged so as to be able to pivot between a closed position and an open position, and wherein one or several closing elements are attachable to the outside of at least two flap leaves in order to keep these flap leaves in their closed position and to prevent the flap leaves from pivoting and are configured to fail during drilling of the soil-displacement drill into the surface in such a manner that these closing elements do not impede pivoting of the flap leaves, wherein the drill head of the assembly is attached to one end of the drill pipe and the flap leaves of the drill head are arranged for closing off the end of the drill pipe in the closed position and for at least partly making the end of the drill pipe freely accessible in the open position, wherein the soil-displacement drill comprises one or several projections which are provided at the end of the drill pipe or on an annular wall section of the drill head, and in that each flap leaf comprises at least one corresponding recess, so that the flap leaves are arranged on the one or several projections in a secured manner in their closed position.

10. Soil-displacement drill according to claim 9, wherein every two mutually adjoining flap leaves are secured on the same said projection in their closed position at the location where they adjoin.

Description

(1) In this detailed description, reference numerals are used to refer to the attached drawings, in which

(2) FIG. 1 shows the bottom part of a soil-displacement drill according to the present invention with a part of its drill pipe, its drill head and its closing element in perspective, with the drill head in a closed position;

(3) FIG. 2 shows the part of the soil-displacement drill from FIG. 1 in a front view with the drill head in a closed position;

(4) FIG. 3 shows the bottom part of an alternative soil-displacement drill according to the present invention with a part of its drill pipe, its drill head and its closing element in perspective, with the drill head in a closed position;

(5) FIG. 4 shows the part of the soil-displacement drill from FIG. 3 in a front view, with the drill head in a closed position;

(6) FIG. 5 shows the closing element from FIGS. 3 and 4 separately in perspective;

(7) FIG. 6 shows a bottom part of the soil-displacement drill from FIG. 3 in perspective, with the closing element worn away and the drill head in an open position;

(8) FIG. 7 shows the part of the soil-displacement drill from FIG. 6 in a front view, with the closing element worn away and the drill head in an open position;

(9) FIG. 8 shows a part of the soil-displacement drill from FIG. 3 at the location of the drill head in more detail in perspective, with the drill head in a closed position;

(10) FIG. 9 shows a part of the soil-displacement drill from FIG. 3 at the location of the drill head in more detail in perspective, with the closing element worn away and the drill head in an open position;

(11) FIGS. 10a and 10b diagrammatically show in several steps how a foundation pile can be formed in a surface by means of a soil-displacement drill according to the present invention.

(12) The illustrated soil-displacement drills (1) comprise a drill pipe (3), a drill head (4) attached thereto and a closing element (6).

(13) In the illustrated embodiments, the drill pipe (3) is substantially cylindrical and is provided with a displacer (11) at the bottom which is formed as a widening of the drill pipe (3). In the illustrated embodiments, at the location of this displacer (11), the drill pipe (3) is provided with a spiral (12) on its outside. Alternatively or additionally, the drill pipe (3) may be provided with one or several external spirals along its entire length. In alternative embodiments, the drill pipe (3) may also be provided without said displacer (11) and/or without spirals.

(14) A cylindrical space (16) extends through the entire drill pipe (3). In specific embodiments, this cylindrical space (16) may be provided with one or several internal spirals.

(15) This drill pipe (3) may, for example, be made of metal.

(16) In the embodiment in FIGS. 1 and 2, the drill pipe (3) is cut off straight at the bottom end of the drill pipe (3) where the drill head (4) is attached, and has an end face which is virtually perpendicular to the direction of drilling. In the embodiment in FIGS. 3-9, projections (22) project with respect to this end face.

(17) The illustrated drill heads (4) in each case comprise two flap leaves (5). In alternative embodiments, a drill head (4) may also be provided with several flap leaves (5).

(18) The flap leaves (5) are arranged so as to be able to pivot between a closed position, for closing off the bottom end of the drill pipe (3), as illustrated in FIGS. 1-4 and 8, and an open position, for at least partly making this end of the drill pipe (3) freely accessible, as illustrated in FIGS. 6, 7 and 9. To this end, each flap leaf (5) is hingedly attached to the drill pipe (3) by means of a hinge (9).

(19) In the embodiment in FIGS. 1-2, this hinge (9) extends substantially inside a space in the pipe wall (15) of the drill pipe (3) in the closed position of the flap leaf (5). To this end, this pipe wall (15) is made sufficiently wide at the location of the displacer (11) in order to provide these spaces for the hidden hinges (9) which end at the said end of the drill pipe (3).

(20) In the embodiment in FIGS. 3-9, this hinge (9) extends substantially inside a space (24) in the flap leaf (5) in the closed position of the flap leaf (5). To this end, an attachment body (25) is provided at the bottom of the displacer (11) for each flap leaf (5) and is arranged within the width of the pipe wall (15) of the displacer (11) and is bevelled in order to be able to extend substantially inside the space (24) in the flap leaf (5) in the closed position. A hinge pin (26) is arranged through this attachment body (25) and in the flap leaf (5) in order to attach this flap leaf (5) to this attachment body (25) so as to be able to pivot about this hinge pin (26).

(21) In the second embodiment, the flap leaves (5) are also provided with recesses (23) which correspond to the aforementioned projections (22) in such a way that the flap leaves (5), in their closed position, are secured with respect to these projections (22), this at the location where the flap leaves (5) adjoin each other.

(22) The drill head (4) tapers away from the drill pipe (3). In this case, the illustrated flap leaves (5) are of a shell-shaped design and together, in their closed position, form a substantially bit-shaped drill head (4). In this case, these flap leaves (5) preferably extend completely next to each other, without overlapping one another.

(23) In their open position, these flap leaves (5) extend substantially inside the smallest surrounding cylinder of the drill pipe (3).

(24) In the illustrated embodiment, each flap leaf (5) is provided with a drill tip part (8) away from the drill pipe (3). In the closed position of the flap leaves (5), the drill tip parts (8) of both flap leaves (5) together form a drill tip (7). This drill tip (7) comprises a cylindrical base body (20) over which the closing element (6) is arrangeable in a clamping manner, and a conical tip (21).

(25) In the first embodiment, the closing element (6) is of annular design and made from plastic. To this end, this closing element (6) may be rigid or elastic.

(26) In the second embodiment, the closing element (6) comprises an annular base body (17) and four engagement elements (19) which are raised with respect to this base body (17). To this end, this closing element (6) is substantially cylindrical and comprises four virtually triangular incisions (18) which delimit the said engagement elements (19). By means of the annular base body (17), this closing element (6) is clamped around the cylindrical base body (20) of the drill tip (7), as can be seen in FIGS. 3, 4 and 8. In this case, the engagement elements (19) project downwards, so that the surface (10) engages with these engagement elements (19) when drilling in a surface (10) in order to break and/or crack the annular base body (17) at the location of the incisions (18). To this end, this closing element (6) is preferably made of plastic by means of injection-moulding.

(27) A drill head (4), such as for example an illustrated drill head (4), and a closing element (6), such as for example an illustrated closing element (6), may together also form a said assembly according to the present invention by means of which an existing soil-displacement drill can be modified to form a soil-displacement drill (1) according to the present invention.

(28) To this end, the existing drill head of this existing soil-displacement drill may be removed and replaced by this new drill head (4). The closing element (6) may be provided on the outside of the flap leaves (5) of this new drill head (4) in order to keep these flap leaves (5) in their closed position.

(29) FIGS. 10a and 10b show how drilling in a surface (10) can take place by means of a soil-displacement drill (1) according to the present invention in order to form a foundation pile (2). The drill pipe (3) and the drill head (4), with the flap leaves (5) in their open position, are first lifted up (step A) to a height at which the flap leaves (5) can be closed easily and the closing element (6) can be fitted (step B). Thanks to the closing element (6), the flap leaves (5) in this soil-displacement drill (1) according to the present invention are easily held together when using it to drill in the surface (10) (step C). The drill (1) is lowered and drilled into the surface (10) (step D). When the drill head (4) is in the surface (10), the flap leaves (5) automatically remain closed during drilling to a deeper level. If the closing element (6) fails completely, the flap leaves (5) thus remain closed when drilling continues. The surface (10) is displaced laterally until the drill pipe (3) is situated in the surface (10) virtually completely (step E). Then, reinforcement (13) is introduced into the drill pipe (3) (step F) and the drill pipe (3) is filled with filling material (14) (step G), such as for example concrete. The closing element (6) is configured in such a way that this closing element (6), even if it does not fail completely, does not impede the flap leaves (5) from opening again when the soil-displacement drill (1) is drilled out of the soil again. Opening these flap leaves (5) may be effected in a simple manner on account of the filling material (14) and the reinforcement (13) when the soil-displacement drill (1) is lifted up. The drill pipe (3) is pulled out of the surface (10) (step H), with the reinforcement (13) and the filling material (14) remaining behind in the surface (10) to form the foundation pile (2) (step I).