GB2603479A

GB2603479A - Tool, system and method for under reaming

Info

Publication number: GB2603479A
Application number: GB2101477.4A
Authority: GB
Inventors: Hibbert Chris; Lasbury Timothy
Original assignee: Roger Bullivant Ltd
Current assignee: Roger Bullivant Ltd
Priority date: 2021-02-03
Filing date: 2021-02-03
Publication date: 2022-08-10
Anticipated expiration: 2041-02-03
Also published as: GB202101477D0; GB2603479B

Abstract

A tool 100 for creating an under reamed void in a hole has an outer collar assembly 101; an inner collar assembly 102, a part of which is located within the outer collar assembly; a shaft member 103, a part of which is located within the inner collar assembly, the shaft member having a proximal end 103pe and a distal end 103de and defining a longitudinal axis 104; and a linkage arrangement 105 pivotably coupled to the inner collar member and a distal portion of the shaft; wherein: the inner collar assembly and the shaft member are rotatable 106, relative to the outer collar assembly, about the longitudinal axis; the shaft member is longitudinally movable 107 relative to the inner collar assembly, and the linkage arrangement is configured such that movement of the distal portion of the shaft member axially towards the inner collar member causes the linkage arrangement to extend radially outwards 108. Also claimed are methods for creating a void under a slab using an underreaming tool operating in an upwards direction, and methods for supporting a slab by forming a void under the slab and then filing the void with a settable material such as a concrete.

Description

TITLE

TOOL, SYSTEM AND METHOD FOR UNDER REAMING

TECHNOLOGICAL FIELD

Examples of the present disclosure relate to a tool, a system and a method for under reaming. Some examples, though without prejudice to the foregoing, relate to a tool for creating an under reamed void, through a hole in a slab, directly beneath the slab.

BACKGROUND

Under reaming tools/under reamers are typically designed to modify a pre-existing hole (e.g., an augered hole or a borehole) by forming an enlargement (e.g., a void/oversized portion of the pre-existing hole), below the surface, in the pre-existing hole.

Conventional under reaming tools, are not always optimal. Conventional under reaming tools may be limited to creating an oversized hole portion/void at depth, e.g., at a bottom of a hole and may not be able to create the same at an upper portion of the hole or proximal to the surface. Conventional under reaming tools may be unable to under ream directly below an existing slab, e.g., creating an under reamed void within a pre-existing hole directly beneath a foundation floor slab. Conventional under reaming tools may require a flushing system to remove spoil generated from the under reamed oversized hole portion/void.

In some circumstances it may be desirable to provide an improved tool, system and method for under reaming. In some circumstances it may be desirable to provide an under-reaming tool, system and method that enables the creation of an under reamed void, through a hole in a slab, directly beneath the slab, wherein such a void may be used in the formation of an underground support structure for the slab. In some circumstances it may be desirable to provide an under-reaming tool, system and method that enables a reduction in resource usage.

The listing or discussion of any prior-published document or any background in this specification should not necessarily be taken as an acknowledgement that the document or background is part of the state of the art or is common general knowledge. One or more aspects/examples of the present disclosure may or may not address one or more of the background issues.

BRIEF SUMMARY

The scope of protection sought for various embodiments of the invention is set out by the independent claims.

Any examples/embodiments and features described in this specification that do not fall under the scope of the independent claims are to be interpreted as examples useful for understanding various embodiments of the invention.

According to at least some examples of the present disclosure there is provided a tool for use in creating an under reamed void in a hole, the tool comprising: an outer collar assembly; an inner collar assembly, a part of which is located within the outer collar assembly; a shaft member, a part of which is located within the inner collar assembly, the shaft member having a proximal end and a distal end and defining a longitudinal axis; and a linkage arrangement pivotably coupled to the inner collar member and a distal portion of the shaft; wherein: the inner collar assembly and the shaft member are rotatable, relative to the outer collar assembly, about the longitudinal axis; the shaft member is movable, relative to the inner collar assembly, along the longitudinal axis; and the linkage arrangement is configured such that movement of the distal portion of the shaft member along the longitudinal axis towards the inner collar member causes the linkage arrangement to extend radially outwards.

In some but not necessarily all examples, the tool further comprises a cutting member pivotably coupled to the inner collar member and the distal portion of the shaft via the linkage arrangement.

In some but not necessarily all examples, the cutting member is removably attached to the linkage arrangement.

In some but not necessarily all examples, the linkage arrangement is configured such that movement, relative to the inner collar member, of the distal portion of the shaft member along the longitudinal axis causes the cutting member to pivot about an axis perpendicular to the longitudinal axis.

In some but not necessarily all examples, the cutting member is pivotable so as to be aligned perpendicularly to the longitudinal axis.

In some but not necessarily all examples, the linkage arrangement is configured such that movement of the distal portion of the shaft member relative to the inner collar member along the longitudinal axis from a first relative axial position to a second relative axial position causes the linkage arrangement to move between a radially retracted configuration and a radially protruding configuration.

In some but not necessarily all examples, the linkage arrangement comprises a cutting member, and wherein the linkage arrangement and cutting member are configured such that: the cutting member is generally parallel to the longitudinal axis in the radially retracted configuration; and/or the cutting member is substantially perpendicular to the longitudinal axis in the radially protruding configuration.

In some but not necessarily all examples, the tool further comprises means for limiting the extent of movement, along the longitudinal axis, of the shaft member relative to the inner collar member.

In some but not necessarily all examples, the outer collar assembly comprises an external clamp engagement surface via which, in use, the outer collar assembly can be clamped into a position by a clamping device.

In some but not necessarily all examples, the linkage arrangement comprises: a first arm; and a second arm; and wherein: a first end of the first arm is pivotably coupled to the inner collar member; a second end of the first arm is pivotably coupled to a first end of the second arm; and a second end of the second arm is pivotably coupled to a distal portion of the shaft member.

In some but not necessarily all examples, the arms are replaceable.

In some but not necessarily all examples, the tool further comprises means, disposed on a distal side of the outer collar member, for locating and/or centralising the distal side of the tool within a hole.

In some but not necessarily all examples, the distal portion of the shaft member comprises means for locating the distal side of the tool within a hole.

According to various, but not necessarily all, examples of the disclosure there is provided: an under-slab reamer tool, a drilling machine, a drilling rig and/or a system comprising the above tool.

According to various, but not necessarily all, examples of the disclosure there is provided a method for creating an under reamed void in a hole under a slab, the method comprising: providing an under-reaming tool having radially extendable cutting means, wherein the under-reaming tool is configurable in a first configuration wherein the cutting means are radially retracted and a second configuration wherein the cutting means are radially extended; inserting; whilst the under-reaming tool is in the first configuration, a portion of the under-reaming tool though a hole in a slab and into a hole under the slab; under reaming the hole with the under-reaming tool, wherein under reaming the hole comprises: changing, whilst the portion of the under-reaming tool is inserted in the hole, the under-reaming tool into the second configuration, and raising, whilst the under-reaming tool is in the second configuration, the under-reaming tool so as to under ream in an upwards direction.

In some but not necessarily all examples, in the second configuration, the radially extended cutting means are substantially horizonal.

In some but not necessarily all examples, the method further comprises raising, whilst the under-reaming tool is in the second configuration, the radially extended cutting means until the radially extended cutting means contacts a lower surface of the slab.

In some but not necessarily all examples, under reaming the hole comprises under reaming the hole to create: a "V" shaped void and/or a void comprising a counter sink shape.

In some but not necessarily all examples, the method further comprises clamping an outer collar of the under-reaming tool such that the clamped outer collar is held in a fixed position relative to an internal collar that is freely rotatable with respect to the fixed outer collar.

According to various, but not necessarily all, examples of the disclosure there is provided a method for supporting a slab, the method comprising: drilling a hole through the slab; drilling a hole, via the hole in the slab, into the ground; performing the above-described method to create a void under the slab and filling the void with settable material.

According to various, but not necessarily all, examples of the disclosure there is provided a method of using a tool as described herein.

While the above examples of the disclosure and optional features are described separately, it is to be understood that their provision in all possible combinations and permutations is contained within the disclosure. Also, it is to be understood that various examples of the disclosure may comprise any or all of the features described in respect of other examples of the disclosure, and vice versa.

According to various, but not necessarily all, examples of the disclosure there are provided examples as claimed in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of various examples of the present disclosure that are useful for understanding the detailed description and certain examples of the present disclosure, reference will now be made by way of example only to the accompanying drawings in which: FIG. 1 schematically illustrates an example of a tool in a retracted configuration; FIG. 2 schematically illustrates an example of the tool of FIG. 1 in a partially extended configuration; FIG. 3 schematically illustrates an example of the tool of FIG 1 in a fully extended configuration; FIGs 4 and 5 schematically illustrates an example of use of the tool of FIG. 1; FIGs 6A -6E schematically illustrate a further example use of the tool of FIGs 7 and 8.

FIG. 7 shows a further example of a tool in a retracted configuration; and FIG. 8 shows a further example of a tool in an extended configuration; and FIG. 9 schematically illustrates an example of method.

The figures are not necessarily to scale. Certain features and views of the figures may be shown schematically or exaggerated in scale in the interest of clarity and conciseness. For example, the dimensions of some elements in the figures can be exaggerated relative to other elements to aid explication. Similar reference numerals are used in the figures to designate similar features. For clarity, all reference numerals are not necessarily displayed in all figures.

DETAILED DESCRIPTION

The figures schematically illustrate, and the following description describes, various

examples of the disclosure.

FIG. 1 schematically illustrates an example of an apparatus according to the present disclosure, namely an under-reaming tool 100 for example an under-slab reaming tool for reaming a void directly beneath a slab. The tool 100 is configured for use in creating an under reamed void in a hole, i.e., an expansion, beneath the surface, of a portion of a pre-exiting hole (such as a pre-drilled, pre-augered or pre-bored hole, bore or shaft), such as is shown in FIG. 6B.

The tool comprises an outer collar assembly 101 that at least partially surrounds an inner collar assembly 102, i.e., the inner collar assembly passes through the outer collar assembly. The inner collar assembly itself at least partly surrounds a shaft member 103, i.e., the shaft member passes through the inner (and also the outer) collar assembly. The shaft member defines a longitudinal axis 104, a proximal end 103pe and a distal end 103de. During typical use, the longitudinal axis corresponds to a vertical axis.

The tool is configured such that the inner collar assembly can freely rotate with respect to the outer collar assembly (schematically illustrated with arrows 106). In this regard, the inner collar assembly is mechanically coupled to the outer collar assembly, e.g., via a bearing arrangement, such that it can freely rotate within the outer collar assembly about the longitudinal axis. The inner collar assembly can thereby rotate independently of the outer collar assembly such that, if the outer collar assembly were clamped/secured into a fixed position such that the outer collar assembly itself is unable to rotate, the inner collar assembly can still freely rotate with respect to the clamped/secured outer collar assembly.

The tool is also configured such that the inner collar assembly is axially fixed with respect to the outer collar assembly. In this regard, the inner collar assembly is mechanically coupled to the outer collar assembly, e.g., via the bearing arrangement, such that it can freely rotate within the outer collar assembly about the longitudinal axis but cannot move axially along the longitudinal axis with respect to the outer collar assembly, i.e., the inner collar assembly cannot move axially independently of the outer collar assembly. Accordingly, if the outer collar assembly were clamped/secured into a fixed position, whilst the inner collar assembly can still freely/independently rotate with respect to the outer collar assembly, the inner collar assembly is unable to move axially with respect to the outer collar assembly upwards or downwards along the longitudinal axis.

The tool is further configured such that the shaft is rotationally fixed with respect to the inner collar assembly such that the shaft is not rotatable relative to inner collar assembly, i.e., they co-rotate and do not freely/independently rotate with respect to one another. In this regard, the shaft is mechanically coupled to the inner collar assembly, e.g., the shaft is linked to the inner collar using a male / female sliding hexagon drive, such that the shaft cannot freely rotate within the inner collar assembly about the longitudinal axis but instead the shaft co-rotates with the inner collar assembly within the outer collar assembly about the longitudinal axis. Accordingly, in use where the shaft is mechanically coupled to a rotary driving machine and receives a rotation force/torque, the rotation/torque can be transmitted to the inner collar assembly.

The tool is also configured such that the shaft is not axially fixed with respect to the inner collar assembly. The shaft is axially moveable (as schematically illustrated by arrows 107) with respect to the inner collar assembly. In this regard, the shaft assembly is mechanically coupled to the inner collar assembly, e.g., the shaft is linked to the inner collar via the male / female sliding hexagon drive, such that it can freely move axially along the longitudinal axis with respect to the inner collar assembly, i.e., the shaft can move axially independently of the inner collar assembly. Accordingly, if the outer collar assembly were clamped/secured into a fixed position and the inner collar assembly were thus axially secured in an axial position with respect to the outer collar assembly, the shaft can still freely/independently move axially with respect to the inner (and outer) collar assembly upwards or downwards along the longitudinal axis. The shaft and the inner collar assembly can also co-rotate within the outer collar assembly. Suitable means may be provided, e.g., a pin and slot arrangement as shown and discussed below with respect to FIGs 7 and 8, for limiting such axial movement of the shaft relative to the inner collar, The tool further comprises a linkage arrangement 105 that is pivotably coupled to the inner collar member and is pivotally coupled to a distal portion of the shaft. The linkage arrangement comprises: a first/upper arm/link 105a and a second/lower arm/link 105b. One end (a proximal end) of the first arm is pivotally connected/hinged to a lower portion of the inner collar assembly, i.e., a portion of the inner collar assembly below the outer collar assembly. The other end (a distal end) of the first arm is pivotally connected/hinged to one end (a proximal end) of the second arm. The other end (a distal end) of the second arm is pivotally connected/hinged to a distal portion of the shaft. The distal end of the second arm may be directly pivotally connected to the end of the shaft (as shown) or indirectly pivotally connected to the end of the shaft via a guide member (as shown and discussed below with regards to FIGs 7 and 8).

A cutting member 109 is attached to the linkage arrangement, such that the cutting member thereby pivotably coupled to the inner collar member and the distal portion of the shaft via the linkage arrangement. The cutting member may be any suitable means for performing a cutting/reaming action on ground material, not least for example: a cutting arm, a blade, a cutter, an elongate plate with protrusions/teeth. As will be discussed further below, the cutting member may also be configured to cut into/clean a settable material such as of a slab (e.g., an extended planar foundation structure such as a concrete foundation slab) so as to clean/clear an underside surface thereof to provide a flat/smoother underside surface. The cutting member may be removably attached so that it can be replaced when it gets worn, i.e., its cutting elements/teeth get worn.

Although only a single linkage arrangement 105 is shown, it is to be appreciated that, in other examples, the tool may comprise two or more linkage arrangements. In some examples, the arms of the linkage arrangement can be removably attached so that they can be replaced with arms of differing length. Using arms of differing length enable an adjustment of the reaming diameter, i.e., the maximal radial extension of the upper arm and its cutting member.

Although only a cutting member 109 is shown, it is to be appreciated that, in other examples, the tool may comprise two or more cutting members, e.g., not least a first cutting member for the first arm and a second cutting member for the second arm, wherein the first cutting member is attached to the first arm at an outer/upper surface thereof and the second cutting member is attached to the second arm at an outer/lower surface thereof (as shown in FIGs 7 and 8).

The outer collar assembly comprises an external clamp engagement surface 101s via which, in use, the outer collar assembly can be clamped into a position by a clamping device. By enabling the outer collar assembly to be secured in a fixed position, and the inner collar assembly being axially fixed (albeit freely rotatable) with respect to the outer collar assembly and the shaft being freely axially moveable with respect to the inner and outer collar assemblies (albeit within a limited range), the shaft can be raised and lowered with respect to the inner (and outer) collar assembly thereby causing actuation of the linkage arrangement and adjusting the configuration of the tool, i.e. between retracted and extended configurations.

As discussed above, the shaft member is axially movable 107, relative to the inner (and outer) collar assembly, along the longitudinal axis. The linkage arrangement is configured such that movement of the distal portion of the shaft member along the longitudinal axis (schematically illustrated with arrows 107, 107' 107" of FIGs 1 to 3) towards the inner collar member causes the linkage arrangement to laterally extend/ extend radially outwards (schematically illustrated with arrows 108, 108' 108" of FIGs 1 to 3). In this regard, upper arm of the linkage arrangement, and the cutting member attached thereto, pivot (schematically illustrated with arrows 110' 110" of FIGs 2 and 3) about an axis 110 perpendicular to the longitudinal axis.

Accordingly, raising the shaft relative to the outer collar causes the arms and cutting member to move outwardly away from the longitudinal axis thereby adjusting the tool from a radially retracted/closed configuration to a radially protruding/open configuration for performing a reaming operation. VVhilst lowering the shaft relative to the outer collar causes the arms and cutting member to move inwardly towards the longitudinal axis thereby adjusting the tool from the protruding/open configuration to the retracted/closed configuration.

FIG. 1 schematically illustrates the tool 100 in a fully retracted/non-deployed/fully closed/stowed configuration, i.e., wherein the arms of the linkage arrangement (and cutting member) are substantially aligned with/generally parallel to the longitudinal axis, though kept at a slight angle thereto such that when the distal portion of the shaft member is brought towards the inner collar member along the longitudinal axis, this urges/forces the arms radially outwards. In such a configuration, the distal portion of the shaft member and the inner collar member may be at their maximally permitted/limited axial separation distance.

FIG. 2 schematically illustrates the tool 100' in a partially extended/partially deployed/partially open configuration, namely wherein the shaft has been raised relative to the inner (and outer) collar assembly such that the distal portion of the shaft member is brought closer towards the inner collar member.

FIG. 3 schematically illustrates the tool 100"in a fully extended/deployed/fully opened configuration, i.e., wherein the first/upper arm of the linkage arrangement (and the cutting member attached thereto) is pivoted so as to be aligned substantially perpendicularly to the longitudinal axis (i.e., horizontal). In such a configuration, the distal portion of the shaft member and the inner collar member may be at their minimally permitted axial separation distance. In this regard, the tool may comprise means for limiting the extent of movement, along the longitudinal axis, of the shaft member relative to the inner collar member. For example, the axial separation distance may be limited to be between a maximum separation distance and a minimum separation distance that respectively correspond to the tool being in the fully retracted/closed and fully extended/opened configurations. Any suitable means may be provided for limiting the extent of movement of the shaft member relative to the inner collar member, not least for example an elongate longitudinal channel of a predetermined length in the shaft and a protrusion from the inner collar member that is received within the channel such that travel of the protrusion is limited to the length of the channel.

As schematically illustrated in FIG 4, the tool 100 is attached to a rotary machine 220, e.g., a drill rig, via a connection interface/intercoupling 221 between the shaft of the tool and a Kelly bar 222 of the drill rig. Additional attachment/lifting points 223 may be provided on the tool via which the tool can be further supported and held in position. For example, chains 224 could be attached to the lifting points and the drilling rig which further supports the tool and, moreover, enable the axial position of the distal portion of the shaft relative to the outer collar to be kept constant during the tool insertion process. Advantageously, this enables the tool to be maintained in its retracted/closed position and prevents the weight of the tool to cause the axial position of the distal portion of the shaft relative to the outer collar to decrease 0.e., for the outer collar to fall down/slide down relative to the tool's shaft which may otherwise occur were the tool to be suspended solely via the Kelly bar connection.

As schematically illustrated in FIG 5, the tool is partially lowered into a pre-existing hole/shaft 225 (i.e., that has been previously drilled/augered/bored). In this regard, the distal portion of the shaft is inserted into the hole along with the lower portion of the inner collar. The outer collar remains above the surface of the hole above ground and is secured into a fixed position, e.g., clamped via a clamp/jaws 226 of the drilling rig. The chains can be removed such that the shaft can move axially with respect to the inner (and outer) collar member.

When the Kelly bar is driven and rotates, the shaft and inner collar member, and also the linkage arrangement attached thereto, all rotate with respect to the outer collar member. When the Kelly bar moves upwards and raises the shaft, the distal portion of the shaft moves towards the axially fixed inner collar member and this forces the linkage arrangement to articulate and extend radially outwards (i.e., as per FIGs 2 and 3). Such rotation of the shaft and lifting of the shaft thereby effects an underreaming action when the arms and cutting member of the tool cut away at the side of the hole to widen it and create an underground void (as discussed further below and shown with respect to FIG. 7D.

An example of use of a tool according to the present disclosure will now be described with regards to the processes illustrated in FIGs 6A -6E.

In this example use, an under-reamer tool 700 (as shown in FIGs 7 and 8 which is similar in operation to that of the tool of FIGs 1 to 3) is used in a process to upgrade a structural capacity of an existing warehouse floor slab so as to provide an increased load bearing capacity of the slab and hence increase the storage capacity within the warehouse.

Typically, in order to provide such an upgrade, the entirety of the slab would be removed and replaced with a newly created slab. As will be discussed below, the under-reamer tool of the present disclosure enables an underreamed void to be created directly beneath the surface of the slab. Moreover, the lower/underside surface of the slab can also be cleaned and levelled by the under-reamer tool to provide a mating surface for an underground support structure formed within the void, namely wherein the under reamed void is filled with a settable material to support the underside surface of the slab, in effect creating an underground vaulted support directly beneath the slab. By negating the requirement to remove the entirety of the existing slab, this reduces unnecessary waste, saving time and reduces cost. Moreover, it enables a saving in resources, not least such as energy and raw materials required to remove the entire slab and forming a completely new slab.

As shown in FIG. 6A, the existing slab 620 is cored through to create a core/hole 621 therethrough. A grid like pattern/array of cores may be created and evenly distributed throughout the slab. By way of a non-limiting example, one or more cored holes, having a diameter of 450mm, may be created through the slab.

As shown in FIG. 6B, a hole 630 is then augered though the core beneath the slab. The depth of the augered hole may be predetermined, e.g., to a designed depth so as to have a volume sufficient to accommodate the spoil from the under-reaming process of FIGs 6C and 6D, and/or to a depth sufficient such that a structural member formed therein (e.g., via the introduction of settable material therein) provide sufficient structural support. By way of a non-limiting example, an augered hole having a diameter of 450mm may be created through and beneath each cored hole.

As shown in FIG. 6C, a tool 700, in its fully retracted/closed configuration, is partially inserted through the cored hole and into the augered hole. Once in position partially inserted in the cored and augered holes, an upper section of the tool that remains above the ground on top of the slab is clamped into position. In this regard, an outer collar 701 of the tool 700 (see FIG. 7) is clamped into a fixed position, above the cored and augered holes, in jaws of a drilling machine or rig clamps of a drilling rig. This stops the whole tool from rotating and lifting relative to the ground when a shaft 703 of the tool is rotated and lifted. This enables the shaft to be rotated and lifted with respect to the ground and the clamped outer collar.

As shown in FIG. 6D, the shaft is rotated and simultaneously raised relative to the clamped outer collar. The raising of the shaft may be effected by raising a rotary head carriage of a drilling rig which is attached to the tool's shaft via a Kelly bar.

By virtue of the configuration of the linkage arrangement, such relative movement of the shaft with respect to the axially fixed outer (and inner) collar forces the upper and lower arms (and cutting members thereon) of the tool to extend/splay radially outwards. This enables the tool to gradually cut away at the ground and allow the arms to move outwards and upwards until the shaft and linkage arrangement is fully raised with the upper arms being horizontally aligned, thereby under reaming the augered hole and creating an underreamed void 640 in the augered hole.

By virtue of the configuration of the linkage assembly that forces the extension of the arms and cutting members, the under reamed shape forms a countersink shape, i.e., a substantially "V" shaped void within the augered hole directly beneath the slab. For example, the linkage arrangement and length of its arms may be configured to provide a maximal reaming diameter (i.e., at the upper part of the "V" shape) of 1300mm, with the void diameter gradually reducing/tapering down to the augered bore diameter of 450mm at the bottom of the "V" shape.

Advantageously, such a countersink shape with non-parallel/angled side walls (as compared to a parallel sided counterbored shape) provides a shape that is optimised with regards to providing sufficient support strength whilst minimising resource usage required to form the under reamed void. A "V" shaped/countersink shaped void reduces resource utilisation as compared to a counterbore shape with parallel sides since a reduced volume of spoil is created (thereby reducing the depth of augered hole required to collect the spoil) as well as reduced wear and energy consumption in creating the smaller volume of under reamed void (as well as augered hole). Yet furthermore, a reduced volume of settable material (e.g., concrete) is required to fill the void to form the underground/under-slab support structure.

Advantageously, due to the linkage arrangement and manner in which the arms and cutting member of the tool are extended, the tool is able to perform an under-reaming action in a vertically upwards direction, i.e., the tool can under ream upwards, e.g., as shown with regards to the under reamed void portion 640'.

Once the upper arms and cutting members are in a horizontally aligned position, and whilst still rotating the shaft, the entire tool can be lifted until the horizontal upper arms contact the underside of the original slab, thereby cleaning and levelling off the underside surface of the slab (illustrated by void portion 640'). The entire tool could be lifted, for example by the clamp lifting the outer collar simultaneously with the shaft being lifted (as shown in FIG. 6D). This could be done by lifting the whole mast of a drilling rig.

During the under-reaming process, spoil 641 can fall through the arms and also through hole guide 722. Advantageously, this avoids the spoil getting in the way of the tool, clogging it up and blocking the cutting member, as well as making it difficult to fully close the tool prior to extraction. Moreover, this also avoids the need for a flushing system required whilst completing the under-reaming phase of the process.

Once the under-reaming operation has been completed, the shaft can be lowered relative to the clamped outer (and inner) collar, e.g., by lowering the rotary head carriage, to close the arms of the tool and support the reamer in its closed position. When fully closed the tool can be lifted out of the cored and augered holes. The chains could be reattached to the lifting points and the drilling rig so as to enable the axial position of the distal portion of the shaft relative to the outer collar to be kept constant during the tool removal process.

A casing, e.g., in this example a 450mm diameter casing, may be installed through the conical void 640 into the augered hole. A further augering operation can then be performed to auger through the casing down to the design depth in order to clean the hole of the spoil 641.

The casing may then be removed and the void can then be filled with a settable material, such as concrete, to form an underground structural support member 650 directly beneath the slab 620 for supporting and strengthening the slab.

FIG. 7 shows an example of a tool 700 in a retracted configuration. FIG. 8 shows the tool in an extended configuration 700". Similar reference numerals are used for the tool 700 to designate similar features to the tool 100 of FIG 1.

The tool 700 comprises a rotating shaft 703 that can be connected to a hexagon drive coupling, thus allowing the shaft to be rotated in a clockwise or anti clockwise direction as well as allowing the shaft to be lifted and lowered vertically for example by a rotary carriage of a drilling rig.

With the shaft in its fully lowered position with respect to the rest of the tool (e.g., as shown in FIG. 7, as compared to the shaft in its fully raised position with respect to the rest of the tool as shown in FIG. 8) and thereby in its closed position/configuration, the tool is able to be partially inserted through a cored hole and down into an augered hole below the cored hole.

The tool comprises an outer collar 701, referred to herein as a lower collar. The lower collar is able to be clamped in jaws of a drilling machine which stops the whole tool from rotating and lifting relative to the ground. The rotating shaft is allowed to rotate by means of a bearing mounted between the lower collar and an inner collar 702, referred to herein as an upper collar.

Rotation and simultaneous vertical movement of the rotating shaft, from the position shown in FIG. 7 to the position shown in FIG. 8, forces upper arms 705a and lower arms 705b to move outwards and upwards until the lower section of the tool (i.e., beneath the lower collar) is fully raised with the upper arms horizontal (as shown in FIG. 8).

The tool comprises a locating means, namely a locating tube 721, for locating and centralising the tool in a cored hole in a slab, as well as aiding positioning of the outer collar on the slab surface. The locating means also helps ensure concentricity when using the drilling machine. The locating means/locating tube is centrally disposed on the tool beneath the lower collar, i.e., at a distal side thereof. The locating tube is configured to fit snugly in the cored hole of the slab so as to locate and centralise the tool in the cored hole, thereby aiding tool alignment and registration with regards to the cored hole.

The tool also comprises a hole guiding means, namely a hole guide 722, disposed at a distal end of the tool. The guiding means/hole guide helps locate and centralise the tool in the augered hole which assists with regards to alignment/registration of the tool with respect to the augered hole. The guiding means/hole guide may be provided as one or more curved plates (as compared to a full circumference tube) so as to facilitate the passage of spoil past the guiding means/hole guide into the augered hole.

To assist with the cutting process and to increase the durability of the tool replaceable upper arm cutting members, referred to herein as upper arm wear (or tooth) plates 709a, and lower arm cutting members, referred to herein as lower arm wear (or tooth) plates 709b can be removably/replaceable attached, e.g., bolted, to each arm.

The tool can be coupled and secured to a rotary driving machine (not shown) that drives the tool's shaft to rotate about its longitudinal axis such that the shaft's longitudinal axis corresponds to the tool's axis of rotation. The rotary driving machine may be any suitable means for providing a rotation force/torque, not least for example: a drilling machine, a rotary boring machine, a drilling rig or a rotary drive.

The tool may be coupled directly or indirectly (e.g. via a torque transmission shaft or a Kelly bar) to the rotary driving machine via and suitable means, for example such as a connection interface (not shown), located at a proximal end of the tool's shaft, that enables both a transmission of rotary motion/torque (i.e. clockwise and anti-clockwise rotation of the shaft) as well as enabling the shaft of the tool to be lowered and raised (which can thereby lower and raise the shaft with respect to the tool's outer and inner collar assemblies [as well as lower and raise the entire tool when the shaft has reached an upper and lower stop defining a maximal extent of axial movement relative to the outer and inner collar assemblies]). The tool may comprise one or more further lifting points/attachment points, e.g., located on the tool's outer and/or inner collar assemblies, via which the entire tool can be raised and lowered (for example where a chain can be releasably attached to the tool to lift/lower the tool).

As shown in FIG. 8, the shaft comprises an elongate longitudinal channel or slot 731. A pin 732 is attached to the inner collar member. The pin protrudes into and engages with the elongate longitudinal channel of the shaft. The tool is configured such that the elongate longitudinal channel guides the movement of the pin (and, thereby, the inner collar) relative to the channel so as to limit the longitudinal/axial movement therealong.

The elongate longitudinal channel 731 is of a predetermined length thereby limiting the extent of axial movement of the shaft member relative to the inner collar member FIG. 9 schematically illustrates a method 900.

In block 901, a portion of an under-reaming tool is inserted through a hole in a slab and into a hole under the slab. The under-reaming tool may be a tool as described above, i.e., having radially extendable cutting means, wherein the under-reaming tool is configurable in a first configuration wherein the cutting means are radially retracted and a second configuration wherein the cutting means are radially extended. The portion of the under-reaming tool may be inserted through the hole in the slab and into the hole under the slab whilst the under-reaming tool is in the first configuration.

In block 902, the hole under the slab is under reamed. The hole may be under reamed by the under-reaming tool by changing, whilst the portion of the under-reaming tool is inserted in the hole, the under-reaming tool into the second configuration and whilst rotating the cutting means thereby creating a void under the slab.

In block 903, the under-reamer tool is raised to ream the hole under the slab in an upwards direction. The tool may be raised, whilst the under-reaming tool is in the second configuration and the cutting means rotating, so as to under ream in an upwards direction until the cutting means contact a lower surface of the slab, thereby creating a void directly underneath the slab.

The method may further comprise, prior to the above method actions 901 -903, drilling or coring the core through the slab and drilling or augering the hole beneath the slab.

The method may further comprise, after the above method actions 901 -903, filling the under reamed void with a settable material.

Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

Features described in the preceding description can be used in combinations other than the combinations explicitly described.

Although functions have been described with reference to certain features, those functions can be performable by other features whether described or not.

Although features have been described with reference to certain examples, those features can also be present in other examples whether described or not. Accordingly, features described in relation to one example/aspect of the disclosure can include any or all of the features described in relation to another example/aspect of the disclosure, and vice versa, to the extent that they are not mutually inconsistent.

Although various examples of the present disclosure have been described in the preceding paragraphs, it should be appreciated that modifications to the examples given can be made without departing from the scope of the invention as set out in the claims. For example, it is appreciated that modifications may include not least changing the dimensions of various of the under-reamer components (e.g., lengths and diameters) so as to suit a particular design specification/hole diameter and underreamed void size. The tool could be comprised of any number of arms from one upwards. The various components (e.g., not least the arms, cutting means and shaft) could be removeable so that they can be replaced with other parts, e.g., of differing dimensions. Different approaches to providing the wear/tooth plates or cutting faces could be envisioned including adding plates to either or both sides of each arm or either upper and/or lower arms.

The term 'comprise' is used in this document with an inclusive not an exclusive meaning. That is any reference to X comprising Y indicates that X can comprise only one Y or can comprise more than one Y. If it is intended to use 'comprise' with an exclusive meaning then it will be made clear in the context by referring to "comprising only one..." or by using "consisting".

In this description, the wording 'connect' and 'couple' and their derivatives mean operationally connected/coupled. It should be appreciated that any number or combination of intervening components can exist (including no intervening components), i.e., so as to provide direct or indirect connection/coupling.

In this description, reference has been made to various examples. The description of features or functions in relation to an example indicates that those features or functions are present in that example. The use of the term 'example' or for example, can' or may' in the text denotes, whether explicitly stated or not, that such features or functions are present in at least the described example, whether described as an example or not, and that they can be, but are not necessarily, present in some or all other examples. Thus 'example', 'for example', can' or may' refers to a particular instance in a class of examples. A property of the instance can be a property of only that instance or a property of the class or a property of a sub-class of the class that includes some but not all of the instances in the class.

In this description, references to "a/an/the" [feature, element, component, means...] are to be interpreted as "at least one" [feature, element, component, means...] unless explicitly stated otherwise. That is any reference to X comprising a/the Y indicates that X can comprise only one Y or can comprise more than one Y unless the context clearly indicates the contrary. If it is intended to use a or the' with an exclusive meaning then it will be made clear in the context. In some circumstances the use of at least one' or one or more can be used to emphasise an inclusive meaning but the absence of these terms should not be taken to infer any exclusive meaning.

The presence of a feature (or combination of features) in a claim is a reference to that feature (or combination of features) itself and also to features that achieve substantially the same technical effect (equivalent features). The equivalent features include, for example, features that are variants and achieve substantially the same result in substantially the same way. The equivalent features include, for example, features that perform substantially the same function, in substantially the same way to achieve substantially the same result.

In this description, reference has been made to various examples using adjectives or adjectival phrases to describe characteristics of the examples. Such a description of a characteristic in relation to an example indicates that the characteristic is present in some examples exactly as described and is present in other examples substantially as described.

The above description describes some examples of the present disclosure however those of ordinary skill in the art will be aware of possible alternative structures and method features which offer equivalent functionality to the specific examples of such structures and features described herein above and which for the sake of brevity and clarity have been omitted from the above description. Nonetheless, the above description should be read as implicitly including reference to such alternative structures and method features which provide equivalent functionality unless such alternative structures or method features are explicitly excluded in the above description of the examples of the present disclosure.

Whilst endeavouring in the foregoing specification to draw attention to those features of examples of the present disclosure believed to be of particular importance it should be understood that the applicant claims protection in respect of any patentable feature or combination of features hereinbefore referred to and/or shown in the drawings whether or not particular emphasis has been placed thereon.

The examples of the present disclosure and the accompanying claims can be suitably combined in any manner apparent to one of ordinary skill in the art.

Each and every claim is incorporated as further disclosure into the specification and the claims are embodiment(s) of the present invention. Further, while the claims herein are provided as comprising specific dependencies, it is contemplated that any claims can depend from any other claims and that to the extent that any alternative embodiments can result from combining, integrating, and/or omitting features of the various claims and/or changing dependencies of claims, any such alternative embodiments and their equivalents are also within the scope of the disclosure.

Claims

CLAIMSWe claim: 1. A tool for use in creating an under rearned void in a hole, the tool comprising: an outer collar assembly; an inner collar assembly, a part of which is located within the outer collar assembly; a shaft member, a part of which is located within the inner collar assembly, the shaft member having a proximal end and a distal end and defining a longitudinal axis; and a linkage arrangement pivotably coupled to the inner collar member and a distal portion of the shaft; wherein: the inner collar assembly and the shaft member are rotatable, relative to the outer collar assembly, about the longitudinal axis; the shaft member is movable, relative to the inner collar assembly, along the longitudinal axis; and the linkage arrangement is configured such that movement of the distal portion of the shaft member along the longitudinal axis towards the inner collar member causes the linkage arrangement to extend radially outwards.
2. The tool of claim 1, further comprising a cutting member pivotably coupled to the inner collar member and the distal portion of the shaft via the linkage arrangement.
3. The tool of claim 2, wherein the cutting member is removably attached to the linkage arrangement.
4. The tool of claim 1 or 2, wherein the linkage arrangement is configured such that movement, relative to the inner collar member, of the distal portion of the shaft member along the longitudinal axis causes the cutting member to pivot about an axis perpendicular to the longitudinal axis.
5. The tool of claim 4, wherein the cutting member is pivotable so as to be aligned perpendicularly to the longitudinal axis.
6. The tool of any previous claim, wherein the linkage arrangement is configured such that movement of the distal portion of the shaft member relative to the inner collar member along the longitudinal axis from a first relative axial position to a second relative axial position causes the linkage arrangement to move between a radially retracted configuration and a radially protruding configuration.
7. The tool of claim 6, wherein the linkage arrangement comprises a cutting member, and wherein the linkage arrangement and cutting member are configured such that: the cutting member is generally parallel to the longitudinal axis in the radially retracted configuration; and/or the cutting member is substantially perpendicular to the longitudinal axis in the radially protruding configuration.
8. The tool of any previous claim, further comprising means for limiting the extent of movement, along the longitudinal axis, of the shaft member relative to the inner collar member.
9. The tool of any previous claim, wherein the outer collar assembly comprises an external clamp engagement surface via which, in use, the outer collar assembly can be clamped into a position by a clamping device.
10. The tool of any previous claim, wherein the linkage arrangement comprises: a first arm; and a second arm; and wherein: a first end of the first arm is pivotably coupled to the inner collar member; a second end of the first arm is pivotably coupled to a first end of the second arm; and a second end of the second arm is pivotably coupled to a distal portion of the shaft member.
11. The tool of claim 10, wherein the arms are replaceable.
12. The tool of any previous claim, further comprising means, disposed on a distal side of the outer collar member, for locating and/or centralising the distal side of the tool within a hole.
13. The tool of any previous claim, wherein the distal portion of the shaft member comprises means for locating the distal side of the tool within a hole.
14. An under-slab reaming tool, a system, a rotary machine, or a drilling rig comprising the tool as claimed in any previous claim.
15. A method for creating an under reamed void in a hole under a slab, the method comprising: providing an under-reaming tool having radially extendable cutting means, wherein the under-reaming tool is configurable in a first configuration wherein the cutting means are radially retracted and a second configuration wherein the cutting means are radially extended; inserting, whilst the under-reaming tool is in the first configuration, a portion of the under-reaming tool though a hole in a slab and into a hole under the slab; under reaming the hole with the under-reaming tool, wherein under reaming the hole comprises: changing, whilst the portion of the under-reaming tool is inserted in the hole, the under-reaming tool into the second configuration, and raising, whilst the under-reaming tool is in the second configuration, the under-reaming tool so as to under ream in an upwards direction.
16. The method of claim 14, wherein, in the second configuration, the radially extended cutting means are substantially horizonal.
17. The method of claim 14 or 15, further comprising raising, whilst the under-reaming tool is in the second confiauration, the radially extended cutting means until the radially extended cutting means contacts a lower surface of the slab.
18. The method of claim 14, 15 or 16, wherein under reaming the hole comprises under reaming the hole to create: a "V" shaped void and/or a void comprising a counter sink shape.
19. The method of any of claims 14 to 17, further comprising clamping an outer collar of the under-reaming tool such that the clamped outer collar is held in a fixed position relative to an internal collar that is freely rotatable with respect to the fixed outer collar.
20. A method for supporting a slab, the method comprising: d lling a hole through the slab; drilling a hole, via the hole in the slab, into the ground, performing the method of claim 16 to create a void under the slab; and filling the void with settable material