AUXILIARY EQUIPMENT FOR USE WITH DRILLING APPARATUS

Abstract

An auxiliary working apparatus configured for use with a drilling apparatus including a platform which is supported above ground and a drill pipe which extends through a hole in the platform to be displaced into the ground for drilling a hole in the ground. The drill pipe is of a type having a central passage along which pressurized air is blown. The apparatus is mounted to an underside of the platform by means of an auxiliary support structure which includes a hub, a number of vanes mounted to the hub and a hydraulic motor for driving the hub. The vanes are in the form of flexible rubber flaps which are circumferentially spaced and extend radially outwardly from the hub. The vanes revolve around the drill pipe so as to displace chippings which are blown from the hole during a drilling operation, outwardly away from the drill pipe to form an annular mound around and spaced from the hole.

Description

FIELD OF INVENTION

This invention relates to auxiliary equipment for use with drilling apparatus.

BACKGROUND TO INVENTION

The auxiliary equipment as herein envisaged, hereinafter referred to specifically as an auxiliary working apparatus, is provided particularly for use with a drilling apparatus of the type that is used in mines, for drilling holes into the ground. Such a drilling apparatus generally includes a support structure, for the stable support of the apparatus in the region where drilling is required, a drill motor mounted on the support structure and a drill pipe formed of a number of drill pipe sections, that is operatively connected to an output of the drill motor for the rotation thereof. Such a drilling apparatus includes also a displacement mechanism for displacing the drill motor and particularly the drill pipe connected thereto along a longitudinal axis of the drill pipe, for drilling purposes, the drilling operation usually including the insertion of extension segments in line with the drill pipe in order to permit drilling of “deep” holes. The support structure also includes a platform at a spaced location above the ground in which a hole is to be drilled, the drill pipe passing through a hole in the platform to permit the platform to effectively form a barrier between the operating parts of the drilling apparatus, i.e. the drill motor and the displacement mechanism, and the ground in which a hole is to be drilled.

The above construction is important because a drilling operation provides for the displacement of compressed air along a passage defined through the drill pipe to the drilling segment that defines the drill pipe head, this head defining a larger diameter than the remainder of the drill pipe and thus providing for an annular space to be formed in the ground around the drill pipe where it has drilled a hole into the ground. In addition to the compressed air fulfilling a cooling function, it serves also to displace soil displaced by the drilling operation, commonly and hereinafter referred to as chippings, from the ground through the annular space. The chippings are effectively “blown” from the annular space by the compressed air. As such, and without the platform being located as described, the chippings will blow directly onto the operating parts of the drilling apparatus referred to and this clearly will result in unnecessary wear and tear on these parts, as the chippings are very abrasive.

The continuous displacement of soil from a hole being drilled, as described, is important insofar as clogging of the annular space with chippings will otherwise result, thus causing resistance to the rotation of the drill pipe and unnecessary strain on the drill motor. It has been found, however, that the chippings being “blown” from the annular space referred to, can also pass through the hole in the platform through which the drill pipe extends, thus potentially defeating the objective of the platform, which is to protect the operating parts of the drilling apparatus from the chippings. Still further, chippings blown from the annular space will tend to gather on the ground immediately adjacent the hole being drilled and on the platform immediately adjacent the hole through which the drill pipe extends, this gathering of the chippings resulting in “piles” of chippings being formed that will collapse from time to time and result in the chippings dropping back into the annular space. Clearly, for as long as air pressure is sufficient, these chippings will again be “blown” from the annular space, but particularly when air pressure is insufficient or becomes insufficient due to the depth of the hole being drilled, the chippings dropping back into the annular space will result in this space becoming clogged, resulting in interference with the rotation of the drill pipe and unnecessary load being placed on the associated drill motor. In order to avoid motor damage, it is then required to reverse the direction of drill pipe displacement and then again to provide for forward displacement, which can result in the chippings being released and again being blown from the annular space. This clearly will render a drilling operation time inefficient. It is thus an object of this invention to at least alleviate the above known problems that are associated with the use of a drilling apparatus of the type herein envisaged.

WO2007/122528 in the name of the present applicant discloses an auxiliary working apparatus for use with drilling apparatus of the abovementioned type. The auxiliary working apparatus includes a pair of roller-type brushes which are located on opposite sides of the drilling apparatus. The brushes have flexible bristles which surround and contact the drill pipe so as to trap and displace chippings away from the drill pipe.

While effective to a degree, the brushes have been found to be unsatisfactory in a number of respects. Firstly, the applicant has found that the position of the brushes at two opposite sides of the drill pipe is inadequate to trap and displace chippings which emerge from the hole being drilled in an annular stream around the entire circumference of the drill pipe. In order to displace the annular stream of chippings away from the drill pipe, the brushes are sufficiently flexible to envelop and thereby contact the drill pipe causing wear and tear on the brushes and reducing the lifespan of the brushes. Due to the flexibility of the bristles of the brushes which is required in order to contact and envelope the drill pipe, in use, the centrifugal forces exerted by the brushes on the chippings are relatively small, resulting in the chippings being flung a relatively short distance from the hole being drilled. This causes a growing mound of chippings to form adjacent the hole, which must be removed at regular intervals so as to avoid the mould collapsing and the chippings falling back into the hole. Furthermore, separator plates are required in order to ensure separation of the chippings from the brushes. This adds to the expense associated with the use of brushes for displacing chippings away from the drill pipe.

It is an object of the present invention to ameliorate the abovementioned problems associated with the use of brushes as disclosed in WO2007/122528.

Insofar as the auxiliary working apparatus of the present invention applies particularly in relation to the use of a drilling apparatus of the type envisaged above, any reference hereinafter to a drilling apparatus must be interpreted as a reference to drilling apparatus particularly of the type hereinabove described.

SUMMARY OF INVENTION

According to the invention there is provided an auxiliary working apparatus for use with a drilling apparatus for drilling holes into the ground, the drilling apparatus including a support structure which is located on the ground and which includes a platform which forms a barrier at a spaced location above the ground on which the support structure is operatively positioned, a drill motor, a drill pipe displacement mechanism supported by the support structure operatively above the platform and a drill pipe operatively connected to the drill motor and extending through a hole in the platform to be displaced into the ground in which a hole is to be drilled, the auxiliary working apparatus including, in its operative configuration with respect to such a drilling apparatus,

an auxiliary support structure supported by the support structure of the drilling apparatus operatively beneath the platform of the drilling apparatus, the auxiliary support structure including a hub defining a central aperture through which the drill pipe operatively extends;

displacement means comprising a number of vanes which are mounted to the hub of the auxiliary support structure and which are operable to revolve around the drill pipe thereby to displace chippings which are displaced from a hole being drilled by the drill pipe, in use, to a location spaced from the hole; and

operating means for rotating the hub.

The vanes of the displacement means may extend radially outwardly from the hub of the auxiliary support structure. In one embodiment, the vanes may extend outwardly along radial axes intersecting a centre of the hub when the hub is viewed in top plan view. In another embodiment, the vanes may be mounted to the hub so as to extend outwardly at rake angles relative to said radial axes. More specifically, the vanes may extend operatively rearwardly relative to a direction of rotation of the hub.

In a particular embodiment, the vanes may be in the form of panel elements. More specifically, the vanes may be in the form of flexible panel elements. Yet more specifically, the vanes may be in the form of rubber flaps.

The auxiliary support structure of the auxiliary working apparatus of the invention particularly may comprise a structure that can support the displacement means in its required operative configuration with respect to a drill pipe and a hole being drilled by the drill pipe, in use, of the drilling apparatus with which the auxiliary working apparatus is operatively used. Particularly for the support of the auxiliary support structure of the auxiliary working apparatus by the support structure of the associated drilling apparatus, the auxiliary working apparatus may include a set of elongate flexible elements which operatively support the auxiliary support structure in a suspended configuration from the support structure of the drilling apparatus. Such support can be conveniently provided for by a set of chains or cables, while it is envisaged also that this support can be provided for in many different configurations.

The operating means of the auxiliary working apparatus may include a coupling arrangement for coupling the displacement means to a power output associated with the drilling apparatus. Alternatively, the operating means may include drive means operatively connected to the displacement means for operating the displacement means. More specifically, the operating means may include at least one hydraulic motor that can be driven by a hydraulic power supply and that is operatively connected to the hub for rotating the vanes. Clearly, the configuration of the operating means is greatly variable, being determined particularly by the mode of operation of the displacement means which is to be operated thereby.

The auxiliary working apparatus of the invention may comprise apparatus that is particularly adapted for use with a drilling apparatus for drilling holes into the ground, effectively serving as a dedicated chippings displacement apparatus for this purpose.

It is envisaged still further that the auxiliary working apparatus of the invention can be provided as part of a drilling apparatus and, as such, the invention extends also to such a drilling apparatus which includes an auxiliary working apparatus, in accordance with the invention, as part thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

Further features of the auxiliary working apparatus of the invention and the operation thereof are described in more detail hereinafter with reference to an example of such an apparatus, which is illustrated in the accompanying diagrammatic drawings. In the drawings:

FIG. 1 shows a partly sectional side view of an auxiliary working apparatus in accordance with the invention, mounted to a support structure of a drilling apparatus for drilling holes into the ground; and

FIG. 2 shows a sectional side view of the auxiliary working apparatus of FIG. 1 mounted to a drilling apparatus, illustrating the manner in which chippings are displaced during a drilling operation;

FIG. 3 shows a perspective view of the auxiliary working apparatus of FIG. 1; FIG. 4 shows a side view of the auxiliary working apparatus of FIG. 1; and

FIG. 5 shows a bottom plan view of the auxiliary working apparatus of FIG. 1.

DETAILED DESCRIPTION OF THE DRAWINGS

Referring to the drawings, an auxiliary working apparatus for use with a drilling apparatus for drilling holes into the ground, in accordance with the invention, is designated generally by the reference numeral 10. The auxiliary working apparatus 10 comprises, broadly, an auxiliary support structure 12 including a hub 14, a number of vanes 16 mounted to the hub and a hydraulic motor 18 for driving the hub.

The auxiliary working apparatus 10 is configured for use with a drilling apparatus designated by the reference numeral 50, for drilling holes into the ground. The drilling apparatus 50 generally includes a support structure comprising a number of upright support columns 52 which are located on a ground surface 54 and a platform 56 which is supported in a horizontal configuration by the support columns in an arrangement wherein the platform forms a barrier at a spaced location above the ground. The drilling apparatus further includes a drill motor (not shown), a drill pipe displacement mechanism (not shown) supported by the support columns and a drill pipe 58 which is operatively connected to the drill motor which extends through a hole in the platform 56 to be displaced into the ground in which a hole 53 is to be drilled. The drill pipe defines a central longitudinal passage 59 along which compressed air travels downwardly along the drill pipe. The drill pipe has an opening at its lower end through which the air exits the drill pipe into an annular space between the drill pipe and the side wall of the drilled hole.

The auxiliary working apparatus 10 is mounted to an operative underside of the platform 56 by means of the auxiliary support structure 12 which also houses the hydraulic motor 18. The hub 14 defines a central passage 20 within which the drill pipe 58 is rotatably received. The auxiliary support structure includes four circumferentially equi-spaced elongate support elements 17 which support the auxiliary support structure in a suspended configuration from the platform 56. More specifically, the support elements are pivotally connected at upper and lower ends thereof to the platform and the hub, respectively.

The vanes 16 are mounted to the hub 14 by means of mounting brackets 25 and extend radially outwardly therefrom. More specifically, the vanes are flexible rubber panels in the form of flaps. Each flap has a diagonally-extending strengthening rib 22.

With reference to FIG. 5 of the drawings, the rubber flaps are circumferentially spaced and mounted to the hub 14 so as to extend outwardly at rake angles a of between 10° and 30° defined between planes “X” extending through centres of flaps 16 and radial axes R which intersect at an axis of rotation P of the hub. More specifically, the flaps extend operatively rearwardly relative to a direction of rotation A of the hub.

During the use of the auxiliary working apparatus 10 and of the associated drilling apparatus 50, the flaps 16 revolve around the drill pipe 58 thereby displacing chippings which are blown from the hole 53 being drilled by the drill pipe 58, to a location spaced from the hole. As can be seen in FIG. 2 of the drawings, an annular mound 26 of chippings is formed around the hole 53 and spaced therefrom. In FIG. 2, arrows depict the direction of travel of compressed air down the centre of the drill pipe and thereafter compressed air together with chippings entrained therein, up within the annular space surrounding the drill pipe and finally, the direction of travel of chippings which are flung outwardly by the rubber flaps. The rubber flaps contact the chippings as they emerge from the hole and displace the chippings operatively outwardly, i.e. as a result of centrifugal forces acting on the chippings, effectively flinging the chippings outwardly to a spaced location from the hole where the annular mound 26 of chippings is formed and where the chippings can be collected.

The fact that the chippings are displaced to a spaced location from the hole being drilled ensures that these chippings cannot again drop into the hole, this being a problem commonly associated with the drilling of holes in environments as envisaged and resulting in clogging of holes with chippings, particularly where the pressure of the compressed air provided to blow the chippings from the annular space defined is no longer sufficient, which can particularly occur also where very deep holes are drilled. By preventing such clogging, unnecessary loads on the drill motor is avoided, while the release of chippings from within the annular space, which would otherwise be required and which is associated with momentarily reversing the displacement of the drill pipe, also will not be required. This will ensure time efficiency associated with the drilling of holes which, without the auxiliary working apparatus, often is negatively affected.

The rubber flaps which revolve around the drill pipe during a drilling operation are durable and effective in displacing the chippings an appreciable distance from the drill pipe. Furthermore, as the flaps revolve around the drill pipe, chippings emerging from entire circumference of the annular space surrounding the drill pipe are displaced away from the drill pipe. This provides for effective collection and removal of chippings from an area surrounding the entire circumference of the drill pipe. Furthermore, as the flaps do not make contact with the drill pipe during operation, they are not subjected to wear and tear from contact with a drill pipe.

It will be understood that the auxiliary working apparatus 10 can be provided as a dedicated unit, i.e. a chipping displacement apparatus and that the apparatus either can be separately provided or provided as part of a drilling apparatus. When provided as part of a drilling apparatus, the invention extends clearly also to such a drilling apparatus which includes auxiliary working apparatus as described as part thereof.

Claims

1. An auxiliary working apparatus for use with a drilling apparatus for drilling holes into the ground, the drilling apparatus including a support structure which is located on the ground and which includes a platform which forms a barrier at a spaced location above the ground on which the support structure is operatively positioned, a drill motor, a drill pipe displacement mechanism supported by the support structure operatively above the platform and a drill pipe section operatively connected to the drill motor and extending through a hole in the platform to be displaced into the ground in which a hole is to be drilled, the auxiliary working apparatus including, in its operative configuration with respect to such a drilling apparatus,

an auxiliary support structure supported by the support structure of the drilling apparatus operatively beneath the platform of the drilling apparatus, the auxiliary support structure including a hub defining a central aperture through which the drill pipe operatively extends;

displacement means comprising a number of vanes which are mounted to the hub of the auxiliary support structure and which are operable to revolve around the drill pipe thereby to displace chippings which are displaced from a hole being drilled by the drill pipe, in use, to a location spaced from the hole; and

operating means for rotating the hub.

2. The auxiliary working apparatus as claimed in claim 1, wherein the hub has a sealing device which forms a seal between the hub and the drill pipe, in use, which resists displacement of chippings through said central aperture of the hub.

3. The auxiliary working apparatus as claimed in claim 1, wherein the vanes of the displacement means extend radially outwardly from the hub of the auxiliary support structure.

4. The auxiliary working apparatus as claimed in claim 3, wherein the vanes extend outwardly along radial axes intersecting a centre of the hub when the hub is viewed in top plan view.

5. The auxiliary working apparatus as claimed in claim 4, wherein the vanes are mounted to the hub so as to extend outwardly at rake angles relative to said radial axes.

6. The auxiliary working apparatus as claimed in claim 5, wherein the vanes may extend operatively rearwardly relative to a direction of rotation of the hub.

7. The auxiliary working apparatus as claimed in claim 1, wherein the vanes are in the form of panel elements.

8. The auxiliary working apparatus as claimed in claim 7, wherein the vanes are in the form of flexible panel elements.

9. The auxiliary working apparatus as claimed in claim 8, wherein the vanes are in the form of rubber flaps.

10. The auxiliary working apparatus as claimed in claim 1, wherein the auxiliary support structure of the auxiliary working apparatus of the invention particularly comprises a structure that can support the displacement means in its required operative configuration with respect to a drill pipe and a hole being drilled by the drill pipe, in use, of the drilling apparatus with which the auxiliary working apparatus is operatively used.

11. The auxiliary working apparatus as claimed in claim 10, wherein the support of the auxiliary support structure of the auxiliary working apparatus by the support structure of the associated drilling apparatus, the auxiliary working apparatus includes a set of elongate flexible elements which operatively support the auxiliary support structure in a suspended configuration from the support structure of the drilling apparatus.

12. The auxiliary working apparatus as claimed in claim 1, the operating means of the auxiliary working apparatus includes a coupling arrangement for coupling the displacement means to a power output associated with the drilling apparatus.

13. The auxiliary working apparatus as claimed in claim 1, wherein the operating means includes drive means operatively connected to the displacement means for operating the displacement means.

14. A drilling apparatus which includes the auxiliary working apparatus as claimed in claim 1, as part thereof.