GB2172225A - Drilling long holes in confined spaces - Google Patents

Abstract

Apparatus for drilling. e.g. in the roof of a mine working, comprises a unit consisting of a drill drive transfer mechanism 10 positionable at the butt end of the drill bit 13, and a drive means 11 projecting from the drive transfer mechanism away from and on the functional side of the butt end of the drill bit 13. Thus instead of having to accommodate an entire drilling apparatus, including its drive means, between the butt end of the drill bit and the floor of the mine working, it is only necessary to accommodate the drive transfer mechanism. The bit 13 is moved by a chain drive in a support 15, the support being movable upwardly by a hydraulic cylinder on a mounting which is pivotable about 180 DEG on a mounting plate at the end of a boom. The boom is carried on a vehicle. <IMAGE>

Description

SPECIFICATION Drilling apparatus The invention relates to drilling apparatus and particularly to apparatus for drilling holes in the roofs of mine workings in order to insert roof bolts, although holes may also be drilled for methane drainage purposes.

In order to strengthen and secure potentially weak areas of the roof of a mine working, it is known to drill holes into the roof, the holes being deep enough to pass through the potentially weak roof areas and into more secure strata. Roof bolts are then inserted into the holes to secure the potentially weak areas to the more secure strata. The inserted ends of the bolts are frequently held in position by adhesive placed within the holes, whilst load bearing plates are attached to the outer ends, which are threaded, by retention nuts.

A considerable problem arises in attempting to drill deep holes in a restricted space. For example if a five foot vertical hole is required to reach the competent strata, requiring a five foot long drill bit plus the butt end or shank, there may be virtually no space left to accommodate the drill itself between the butt end of the drill bit and the floor of the mine working.

Heretofore holes have been angled but this bolting system is ineffective unless a greater number of bolts are used thus making the system time consuming and costly.

The invention seeks to remove or alleviate this problem by providing drilling apparatus for use in drilling relatively long holes from a confined space, e.g. in the roof of a mine working, the drilling apparatus comprising a unit consisting of a drill drive transfer mechanism positionable at the butt end of the drill bit and a drive means projecting from the drive transfer mechanism away from and on the functional side of the butt end of the drill bit.

For example instead of having to accommodate an entire drilling apparatus, including its drive means, between the butt end of the drill bit and the floor of the mine working, it is only necessary to accommodate the drive transfer mechanism.

Preferably the drive means comprises a hydraulic motor.

The drilling apparatus may comprise thrust means to move the said unit and hence the drill bit, for example to feed the rotating drill bit into the roof of the mine working The thrust means may comprise a chain or other flexible drive mechanism to which the said unit is attached.

The chain drive mechanism may comprise an elongate support having sprockets at its ends, around which a chain passes, the said unit being attached to a point on the chain.

At least one of the sprockets may be driven by hydraulic motor means.

Preferably two hydraulic motors are used.

Preferably the support has means to engage the mine roof to locate and steady the support.

The means to engage the mine roof may comprise a member carrying one or more projections to bite into the mine roof, and may be provided at the end of the support.

The member may be movable into engagement with the mine roof by means of a hydraulic ram.

Preferably one end of the support has a guide to steady and guide the drill bit.

The guide may comprise a pair of jaws for sliding engagement around the drill bit.

The jaws serve two purposes. First, to guide the drill bit during the initial stages and secondly, to guide a roof bolt into the prepared hole containing bonding medium, while the bolt is pushed into the prepared hole and subsequently rotated to "mix" the medium.

The jaws may be movable towards and/or away from one another by a hydraulic ram, to enable the drill bit or roof bolt to be fitted into the apparatus.

The elongate support may comprise guide rails on which the said unit is mounted.

Preferably the elongate support is mounted on a frame and is rotatable and/or tiltable relative thereto, for example for transportation and/or to enable horizontal or inclined holes to be drilled if desired.

The frame may be provided with stabilising jack means to provide a resistance to the drilling forces.

Preferably the drilling apparatus is mounted on a boom of a carrying vehicle.

The invention includes drilling apparatus having a frame adaptable for mounting on a vehicle or like transportation means, said frame having stabilising means for use during the drilling process, said frame being provided with a rotatable mounting for a drilling machine which comprises elongate support means for the translation of a drive mechanism carriage therealong, said support means having a two-part drill guide and steady means attached to the mounting and whereby the drilling machine including the drill drive means may be accommodated within the length of the elongate support means.

By way of example, a specific embodiment of drilling apparatus will now be described, with reference to the accompanying drawings, in which: Figure 1 is a side view of an embodiment of drilling apparatus according to the invention, partially in cross-section; Figure 2 is a view on arrow 11 of Fig. I, partially in cross-section; Figure 3 is a crossection on line Ill-Ill of Fig. 1; Figure 4 is a plan view, partially in section; Figure 5 is a view similar to Fig. 1 but showing a mounting for the apparatus; Figure 6 is a side view of the apparatus mounted on a carrying vehicle; Figure 7 is a rear view of a mounting plate carried by the vehicle; and Figure 8 is a view illustrating the movement of links carried by the mounting plate.

The drilling apparatus comprises a relatively shallow gearbox 10 from which a hydraulic motor 11 projects upwardly. Also projecting upwardly from the gearbox 10, adjacent to the motor 11, there is a chuck 12 for connecting to the gearbox an elongate drill bit 13.

By arranging for the motor 11 and the drill bit 13 to project upwardly in parallel from the gearbox 10, instead of having the motor 11 co-linear with the drill bit, it is possible to accommodate the drilling apparatus in the smallest possible space between the floor of a mine working and the roof 14.

In order to raise the drill bit and hence drive it into the roof 14, there is provided, adjacent to the gearbox 10, a lifting apparatus comprising an upwardly extending support frame 15.

Mounted within the support frame, at the lower end thereof, there is a first sprocket wheel 16. The sprocket wheel is rotatable by means of a pair of opposed hydraulic motors 17, protected by housings 17a.

Towards the upper end of the support frame 15 there is a transversely extending web 18 to which a screw-threaded rod 19 is attached by means of a pair of nuts 20. Attached to this rod 19 is a metal block 21 slidable between guides 22 attached to the support frame. Also slidable between the guides 22 is a U-shaped bracket 24 between the arms of which an upper sprocket wheel 25 is rotatably mounted. The bracket 24 is further guided by a pair of rods 23 which project from the bracket 24 and pass slidably through the block 21. Two compression springs 24a respectively surround the two rods 23. A continuous chain 26 extends around the two sprocket wheels. The springs 24a maintain the chain under tension and the nuts 20 enable the tension to be adjusted.

Attached to a point on the chain 26 is a bracket 27 which is guided for vertical movement by a pair of plates 28 which engage behind flanges 29 of the support frame 15.

Attached to the bracket 27 is the gearbox 10.

Thus by driving the motors 17 and sprocket 16 the chain is rotated, causing the bracket 27, and hence the gearbox 10 and drive 11, 12, to rise.

Turning now to Fig. 5, it will be seen that the support frame 15 is itself slidably supported on a mounting 30 by means of plates 31 which engage around flanges 32 of the support frame. Connected between the lower end of the frame 15 and the upper end of the mounting 30 is a hydraulic ram 33.

In use, the mounting 30 is rigidly supported, as described in more detail below, by a carrying vehicle. In order to locate and support the upper end of the support frame, the support frame is provided with an upper member 28a which carries pointed spikes 29a. In order to urge the member 28a against the mine roof the hydraulic ram 33 is simply retracted.

The member 28a also carries a guide for the drill bit 13 in the form of a pair of jaws 34 each mounted on an arm 35, (see Fig. 4), pivoted at 36 on the member 28a. The arms 35 extend beyond the pivot 36, on the opposite of the pivot from the jaws 34, and between these extended portions of the arms 35 there is mounted a hydraulic ram 37 for opening and closing the jaws.

In order to use the apparatus the lower end of the support frame 15 is positioned adjacent to the mine floor by the carrying vehicle or the like, immediately underneath the place where a hole is to be drilled. The gearbox 10 is in the lower position shown in full lines in Fig. 1. The jaws 34 are open. The drill bit 13 is then fitted into the chuck and the leading end of the drill bit is positioned between the jaws 34 which are then closed around the drill bit. The ram 33 is then retracted to drive the spikes 29a into the mine roof to hold the support frame securely in position with the leading end of the drill bit 13 in register with the location where the hole is to be drilled.

The motor 11 is then switched on to rotate the drill bit and the motors 17 are switched on to rotate the chain and hence gradually raise the gearbox 10 to the upper position shown in chain lines in Fig. 1. The sequence of operations can then be reversed to remove the drill bit.

The way in which the drilling apparatus is mounted on the carrying vehicle will now be described in more detail. The carrying vehicle 38 is shown in side view in Fig. 6 and comprises two sections, 39 and 40, pivotally connected together at 41. Each section has a pair of road wheels 42. The section 39 carries the prime mover 43 and driver's cab 44 while the section 40 carries a pivotable boom 45. Pivotally mounted on the boom 45 is a mounting plate 46 which can be tilted by means of a ram 47. At its upper end the plate 46 carries a shaft 48 on which the mounting 30 is secured. The shaft 48, and hence the mounting 30 and frame 15, can be rotated with respect to the plate 46 as will now be described in detail with reference to Figs. 7 and 8.

Fig. 7 is a rear view of the plate 46 and it will be seen that attached to the shaft 48 is a bracket 49 which is rigid with the shaft. Pivotally connected to the bracket 49 at 50 is a first link 51 having a very slight angle therein.

Pivotally connected to the other end of the link 51 is a second link 52 which has a more pronounced angle therein. The other end of the link 52 is pivotally connected at 53 to a fixed location on the plate 46. Connected to the pivot 54 which interconnects the links is one end of a ram 55, the other end of the ram being pivotally connected at 56 to another fixed location on the plate 46.

Fig. 8 shows in full and chain lines various positions which are taken up by the links 51 and 52 as the ram 55 advances and retracts.

Movement of the ram 55 obviously brings about pivotal movement of the link 52 about the pivot point 53. Because of the relative dimensions and positions of the links 51 and 52 and their associated pivot points, the link 51 pivots with respect to the link 52. Thus movements of the link 52, and additional movements of the link 51 relative to the link 52, are communicated to the bracket 49 and the effect of this is that the frame 15 can be pivoted from the vertical through 90"in each of two opposite directions. In other words the frame 15 can pivot through a total arc of 1800 passing from one horizontal position to a vertical position to another horizontal position.

Because the frame 15 can be rotated in this way, and because the mounting plate 46 can be tilted and raised, by movements of the boom 45 and ram 47, the drilling apparatus is extremely versatile. A large number of different positions can be adopted by the frame 15 both for transport through a roadway system and for drilling purposes. For instance, instead of being used to drill vertical holes into a mine roof, the drill may also be used to drill inclined holes, for example by positioning the frame 15 in the position shown in chain lines in Fig. 6. Furthermore, by positioning the frame 15 horizontally, holes can be drilled into the walls of a mine working, or into the face of the working, which may be required for certain conditions.

Although the drilling apparatus is particularly suitable for use in confined spaces, for example where it may be desired to drill a five foot hole into the roof of a mine working which is only six foot high overall, the apparatus can be used to drill into much higher roofs. The frame 15 can be raised a significant amount with respect to the mounting 30 by retraction of the ram 33 and further height can be gained by raising the boom 45 of the carrying vehicle.

In order to relieve the boom 45 of at least some of the load created during drilling, the plate 46 also carries a pair of stabilising jacks 61, 62. These can be lowered into contact with the ground during drilling.

If desired the boom 45 of the vehicle may be connected to the plate 46 by means of the attachment device described in our co-pending U.K. Patent Application No. 8236781.

The invention is not restricted to the details of the foregoing embodiment.

Claims (21)

1. Drilling apparatus for use in drilling relatively long holes from a confined space, the drilling apparaus comprising a unit consisting of a drive means and a drive transfer means for transferring drive from the drive means to a drill bit, the drill drive transfer mechanism being positioned at the butt end of the drill bit with the drive transfer mechanism and the drive means located substantially on the functional side of the butt end of the drill bit.

2. Drilling apparatus as claimed in claim 1, in which the drive means comprises a hydraulic motor.

3. Drilling apparatus as claimed in claim 1 or claim 2, comprising thrust means to move the said unit and hence the drill bit.

4. Drilling means as claimed in claim 3, in which the thrust means comprises a chain or other flexible drive mechanism to which said unit is attached.

5. Drilling apparatus as claimed in claim 4, in which the thrust means comprises an elongate support having guide means at its ends, around which the flexible drive mechanism passes, the said unit being attached to a point on the chain.

6. Drilling apparatus as claimed in claim 5, in which the guide means comprises sprocket wheels and the flexible drive mechanism comprises a chain.

7. Drilling apparatus as claimed in claim 6, in which at least one of the sprockets is driven by hydraulic motor means.

8. Drilling apparatus as claimed in any one of claims 5 to 7, in which the support has means to engage the mine roof to locate and steady the support.

9. Drilling apparatus as claimed in claim 8, in which the support has means to make frictional engagement with the mine roof.

10. Drilling apparatus as claimed in claim 8, in which the means to engage the mine roof comprises a member carrying one or more projections to bite into the mine roof.

11. Drilling apparatus as claimed in claim 10, in which the said member is provided at one end of the support.

12. Drilling apparatus as claimed in claim 10 or claim 11, in which the said member is movable into engagement with the mine roof by means of a hydraulic ram.

13. Drilling apparatus as claimed in any one of claims 5 to 12, in which one end of the support has a guide to steady and guide the drill bit.

14. Drilling apparatus as claimed in claim 13, in which the guide comprises a pair of jaws for sliding engagement around the drill bit.

15. Drilling apparatus as claimed in claim 14, in which the jaws are movable towards and/or away from one another by a hydraulic ram, to enable the drill bit or roof bolt to be fitted into the apparatus.

16. Drilling apparatus as claimed in any one of claims 5 to 15, in which said elongate support comprises guide rails on which the said unit is mounted.

17. Drilling apparatus as claimed in any one of claims 5 to 16, in which the elongate support is mounted on a frame and is rotatable and/or tiltable relative thereto.

18. Drilling apparatus as claimed in claim 17, in which the frame is provided with stabilising jack means to provide a resistance to the drilling forces.

19. Drilling apparatus as claimed in any.

one of the preceding claims, mounted on a boom of a carrying vehicle.

20. Drilling apparatus having a frame adaptable for mounting on a vehicle or like transportation means, said frame having stabilising means for use during the drilling process, said frame being provided with a rotatable mounting for a drilling machine which comprises elongate support means for the translation of a drive mechanism carriage therealong, said support means having a two-part drill guide and steady means attached to the mounting and whereby the drilling machine including the drill drive means may be accommodated within the length of the elongate support means.

21. Drilling apparatus constructed and arranged substantially as herein described, with reference to the accompanying drawings.