EP2013439A1

EP2013439A1 - Cutting, drilling or grinding apparatus and method

Info

Publication number: EP2013439A1
Application number: EP07793934A
Authority: EP
Inventors: Glenn Michael Ford
Original assignee: Drill TECH Ltd
Current assignee: Drill TECH Ltd
Priority date: 2006-04-19
Filing date: 2007-04-19
Publication date: 2009-01-14
Also published as: WO2007120059B1; WO2007120059A1; AU2007239126A1

Abstract

Cutting drilling or grinding apparatus (1) has a body (3) rotatable about a first axis of rotation (4) and a cutting member (5) to cut, grind or abrade a material to be removed by the apparatus. The cutting member (5) is rotatably mounted on the body about a second axis of rotation (7), which is orthogonal to the first axis of rotation. The cutting member (5) is driven to rotate about the second axis of rotation and at the same time the body (3) is rotated about the first axis of rotation. The cutting member (5) is rotated about the second axis of rotation (7) at a substantially greater rotational speed than the rotational speed of the body (3) about the first axis of rotation.

Description

CUTTING, DRILLING OR GRINDING APPARATUS AND METHOD

FIELD

This invention relates to a method and apparatus for cutting, grinding or machining materials. The invention is particularly, but not solely applicable to drilling or excavating holes or cavities in materials.

BACKGROUND TO THE INVENTION

Existing cutting and grinding processes can be slow and inefficient. In particular, culling processes typically require high torque to turn the drill bit which causes considerable stress and consequent wear to the apparatus and to supporting equipment. Furthermore, drilling operations can be very energy intensive. Moreover, the high stresses involved in traditional cutting or drilling operations mean that it can be difficult in practice to maintain accuracy.

United States patent 4796713 discloses a drilling assembly having a central axis of rotation that carries two separate hemispherical cutting members. Each cutting member is rotatable about an axis transverse to the central axis and has a large cutting surface area. The cutting members rotate slowly with a hammer action and the arrangement is such that a significant axial force (and thus torque) is^' required to place a braking load on the cutting members for effective cutting.

United States published patent application US2001/0045304 A1 discloses a drilling assembly similar to that of US4786713, but uses angled cutting members. Reference is made to the cutting members rotating at the same speed as the rotation about the central axis. Also, the direction of rotation of the cutting members, and their design, is such that a significant downward thrust is provided to the drill bit to assist cutting into the hole. This, and reference to problems with material densities making the apparatus deviate from a desired path suggests that the apparatus removes large volumes of material slowly and requires the application of substantial torque.

There is a need for apparatus or methods which improve the speed or efficacy of cutting, drilling or grinding operations, or allow such operations to be performed with lower torque or energy requirements.

OBJECT OF THE INVENTION It is an object of the present invention to provide an improved cutting, drilling or grinding method or apparatus, or an apparatus or method which reduces the torque required to operate such apparatus.

Alternatively it is an object of the invention to provide a cutting, drilling or grinding method or apparatus which will at least provide a useful alternative to apparatus or methods that are currently available.

SUMMARY OF THE INVENTION

Accordingly in one aspect the invention may broadly be said to consist in cutting, drilling or grinding apparatus including a body rotatable about a first axis of rotation and a cutting member to cut, grind or abrade a material to be removed by the apparatus, the cutting member being rotatably mounted on the body about a second axis of rotation, wherein the second axis of rotation is substantially orthogonal with respect to the first axis of rotation, driving means to rotate the cutting member about the second axis of rotation while also rotating the body about the first axis of rotation, and wherein the driving means is adapted to rotate the cutting member about the second axis of rotation at a substantially greater rotational speed than the rotational speed of the body about the first axis of rotation.

The area traversed by a cutting surface of the cutting member in one revolution of the cutting member is preferably substantially less than the area traversed by the cutting surface in one revolution of the body.

In a preferred embodiment rotation of the cutting member imparts minimal torque about the first axis.

Preferably the axis of rotation of the cutting member is eccentric with respect to the first axis.

The apparatus may include an adjustment means to adjust the position of the second axis of rotation relative to the first axis. Preferably a plurality of cutting members are provided.

In a preferred embodiment the or each cutting member is driven by a gear, pulley or sprocket assembly.

Alternatively the or each cutting member is driven hydraulically.

Preferably the or each cutting member comprises a cutting blade or abrasive blade.

In a further aspect the invention consists in a cutting, drilling or grinding method, the method including the step of rotating a body of a cutting, drilling or grinding apparatus about a first axis of rotation while rotating a cutting member rotatably mounted on the body about a second axis of rotation at a substantially greater rotational speed than the rotational speed of the body about the first axis of rotation, the second axis of rotation being substantially orthogonal to the first axis of rotation, such that the cutting member removes material from an object to thereby remove material from the object.

Preferably the method includes moving the body axially along the first axis of rotation in a direction toward the object to form a hole or cavity.

The method may include the step of varying the position of the second axis relative to the first axis to varying a dimension of the hole or cavity.

A sleeve may be moved behind the body as the apparatus forms the hole or cavity.

The invention may also broadly be said to consist in any novel part, feature or element as described herein or any novel combination thereof.

Further aspects of the invention, which should be considered in all its novel aspects, will become apparent to those skilled in the art upon reading the following description which provides at least one example of a practical application of the invention.

DRAWING DESCRIPTION

A number of embodiments of the invention will now be described with reference to the drawings in which: Figures 1 and 2 are elevations of a first embodiment of cutting, drilling or grinding apparatus according to the invention.

Figures 3 to 5 are elevations of further embodiments of cutting drilling or grinding apparatus according to the invention. Figure 6 is a side elevation of the apparatus of Figure 5.

Figure 7 is a diagrammatic elevation of an auger drill according to the invention.

Figure 8 is a diagrammatic elevation of another embodiment of an auger drill according to the invention.

Figure 9 is a diagrammatic elevation in cross section of a core drill according to the invention.

Figure 10 is a diagrammatic elevation in cross section of a drilling machine for tunneling according to the invention.

Figure 11 is a diagrammatic end elevation of the machine of figure 10.

Figure 12 is a diagrammatic elevation in cross section of a further embodiment of a core drill according to the invention.

Figure 13 is a diagrammatic elevation in cross section of a drilling machine for forming a drain or culvert according to the invention.

Figure 14 is a partial elevation illustrating another embodiment of the machine of figure 13.

Figure 15 is a partial elevation illustrating another embodiment of an auger drill, and one which may be used with the culvert or drain forming apparatus of figures 13 and 14.

Figure 16 is a diagrammatic elevation in cross section of another embodiment of apparatus according to the invention.

Figure 17 is a diagrammatic end elevation in cross section of the apparatus of figure 16.

Figure 18 is a diagrammatic elevation of apparatus of figures 16 and 17. Figure 19 is a diagrammatic elevation of the apparatus of figures 16-18. Figure 20 is a side elevation of a further embodiment of apparatus according to the invention.

Figure 21 is an end elevation of the apparatus of figure 20. Figure 22 is an isometric view of the apparatus of figures 20 and 21. Figure 23 is an isometric view of a further embodiment of the invention Figure 24 is a front elevation of the apparatus of figure 23 Figure 25 is a side elevation of the apparatus of figure 23 Figure 26 is a plan view of the apparatus of figure 23 Figure 27 is an isometric view of a further embodiment of the invention Figure 28 is a front elevation of the apparatus of figure 27 Figure 29 is a side elevation of the apparatus of figure 27 Figure 30 is a plan view of the apparatus of figure 27.

DETAILED DESCRIPTION OF THE DRAWINGS

Throughout the description like reference numerals will be used to refer to like features in different embodiments.

Referring to figures 1 and 2, a first embodiment of cutting, drilling or grinding apparatus according to the invention is shown generally referenced 1. The apparatus comprises a cutting, drilling or grinding bit (referred to as a drill bit in the remainder of this document for convenience) generally referenced 2 which is mounted on a body or support member 3. The support member 3 is rotatable about a first axis 4. The drill bit includes a cutting member in the form of cutting wheel 5 which has a plurality of cutting teeth 6. Although a cutting wheel 5 is disclosed it will be appreciated that a variety of rotatable cutting members of differing geometries may be used. Also, as will be seen from the description further below with reference to the embodiment of figures 5 and 6, the cutting member may be provided in forms other than a wheel.

The teeth 6 of the cutting member may be provided as an integral part of the member, for example being formed as a part of the cutting wheel 5, or may be selectively removable or replaceable. In various embodiments the cutting wheel may include teeth with carbide tips, or the wheel may be diamond studded. Each tooth or abrasive element of the cutting member or members is arranged to remove a small amount of material, rather than a significant amount of material as is known with "macro" drilling operations using known drill bits having large cutting surfaces under conditions of high torque and thrust. Unlike traditional drilling apparatus, the cutting members of the present invention are arranged to perform a "micro removal" operation whereby small amounts of material are removed by an abrasive, grinding or cutting mechanism. The cutting member may remove material from an object by a grinding or abrasive action rather than by cutting. Therefore, rather than teeth per se, the cutting member may include an abrasive surface which provides the "cutting" surface. The teeth or abrasive element(s) of each cutting member are moved at high speed so that a reasonable amount of material is removed in total over a reasonable time period, but with fewer stresses such as torque and/or axial thrust being required.

In a preferred embodiment the cutting members have a small surface cutting area relative to the size of the hole or cavity being formed. Thus in a number of preferred embodiments the cutting members comprise blade-like wheels such as a circular saw blade with teeth or abrasive elements that are substantially in alignment so that only a small surface cutting area actively removes material at any one point in time in use. Therefore, the area traversed by a cutting surface of the cutting member in one revolution of the cutting member is substantially less than the area traversed by the cutting surface in one revolution of the drill bit. In a preferred embodiment the cutting member rotates at a speed of approximately three or more times the speed of rotation about axis 4. In, a more preferred embodiment the cutting member rotates at a speed of approximately five or more times the speed of rotation about axis 4. The ratio of rotational speeds between the cutting member(s) and the support, or the overall speeds of these components can be adjusted for best performance.

The driving means may also be provided by separate gear or pulley/sprocket assemblies and/or by separate motive forces e.g. separate engines or motors.

The drill bit 2 may be provided fixedly or adjustably connected to support member 3 or even as an integral part of the support member. An example of an adjustable connection between the support member and the drill bit 2 is shown in figure 2 in which the drill bit may be adjusted angularly relative to the support member 3 about a pivotal connection 8. Alternatively, or additionally, the bit 2 may be selectively attachable to or detachable from the support member 3. The cutting wheel 5 is rotatably mounted to the drill but about a second axis of rotation 7 which is perpendicular or orthogonal to the first axis of rotation.

In use, the support member 3 is rotated about first axis 4 (for example by mounting the support member 3 in the chuck of an electric drill), and at the same time the cutting wheel 5 is rotated about second axis of rotation 7. Therefore, the cutting or grinding mechanism provided by the cutting member is rotated about axis 4 to form the resultant hole or cavity.

The cutting wheel 5 is rotated much more quickly than the speed of rotation about axis 4.

This drilling mechanism has been found to be very effective, and two examples are discussed further below with reference to figures 22 and 23. Still referring to figures 1 and 2, the cutting wheel 5 may be driven though a series of gear wheels 9 which are rotatably mounted on the support member 3 and if necessary on the drill bit 2. The uppermost wheel 9 (i.e. that furthest from the cutting wheel), may be driven in a variety of ways. For example, it may be in frictional contact with a stationary collar on a drill (such as a hand held electric drill), so that as the support member is rotated the upper wheel 9 also rotates and the rotary movement is conveyed through the remaining wheels 9 to the cutting wheel 5. However, we have found that the apparatus operates most effectively if the speed of rotation of the cutting wheel is substantially greater than that of the drill bit 2.

As can be seen in figure 2, the position of the second axis 7 can be adjusted relative to the first axis 4 so as to be eccentric relative to the first axis to a greater or lesser degree. This can be used to vary a dimension, such as the width, of a hole or cavity being drilled in an object.

In figure 3, another example of a drive mechanism is shown in which a wheel 9 drives the cutting wheel 5 by a belt or chain such a Vee belt 10. In figure 4 a separate drive shaft 11 joumaled in bearings 12 is used to drive the cutting wheel 5. Transmission using angle gears 14 may be used to allow positional adjustment of the axis 7 relative to axis 4.

In figures 5 and 6 the cutting wheel 5 is replaced by a looped flexible cutting member such as cutting chain 15 which may be supported relative to a support member 3 by running in a groove (not shown) provided in the support member. Alternatively or additionally the chain 15 may run about one or more sprockets or rollers (not shown) provided in support member 3. The support member 3 is rotated about its central longitudinal axis, or an axis parallel to its central longitudinal axis to form the cavity or hole. The chain 15 may be substituted by a cutting wire such as a diamond cutting wire for example. Again, the chain or cutting wire is moved by effectively rotating the chain or wire about the support member. The rotation is such that the chain or wire is moved rapidly parallel to the central longitudinal axis of the support member 3 relative to speed of movement of the chain or wire in a direction transverse to the central longitudinal axis.

Figure 7 shows another embodiment of the invention which takes the form of an auger or well drilling machine i.e. a device for drilling holes in ground or similar material. In this embodiment two cutting wheels 5 are provided, each mounted on a generally planar support blade 16 that is attached to support shaft 3. The position of the cutting wheels on the blade 16, or the position of the blade relative to the axis 4 may be adjusted to enable the width of the hole to be varied as required. The use of variably positionable cutting blades also allows holes of varying shapes to be formed. For example, by varying the distance between one or more of the cutting blades 5 and the central axis 4 dependent on the angular position of the blade(s) relative to the axis 4, a hole of a desired regular or irregular cross section (e.g. an ellipse) in a plane perpendicular to the axis 4 can be formed. This has advantages when holes of various cross sectional shapes are required for housing certain conduits or for functions such as road tunnels. As another example, varying the distance between one or more of the cutting blades 5 and the central axis 4 dependent on the vertical position of the blade(s) relative to the axis 4, a hole of a desired cross section in a plane parallel to the axis 4 can be formed.

A pilot drill 17 assists in guiding the drill bit in use, but is not essential. In this embodiment the cutting wheels 5 are driven by hydraulic motors 18 which are fed using supply hoses 19 and return hoses 20 and 21 through a hydraulic circuit from drive motor 22. A further hydraulic motor 23 may be used to turn the support member 3 at a lower speed than that of the cutting wheels 5. In figure 8 a further embodiment of the auger or well drilling apparatus is shown. Auger blades 25 are provided about the support member 3 in this embodiment to rotate therewith and assist in the removal of waste material. The auger blades may be adjusted in region 26 to expand or reduce their diameter dependent on the diameter of the hole being drilled. A high speed shaft 11 is journaled in bearings 12, and angle gear boxes 14 transmit the rotational motion to the cutting wheels 5. A pilot drill 17 is connected directly to the high speed shaft 11 , but is not essential. The cutting blades 5 rotate to move material inwardly for collection by the auger blades 25. A drive motor 27 drives the high speed shaft and a reduction gear box 28 is used to provide a lower speed drive for rotation of the support member 3. Such a drive arrangement may be used in other embodiments, as may the other drive arrangements disclosed herein.

Figure 9 shows a core drill. The core is formed within the support member 3, and electric motors 30 mounted on an outer surface of support member 3 drive the cutting wheels 5 via an appropriate gearbox (not shown), for example using beveled gears such as those shown in the embodiment of figure 8.

In figures 10 and 11 a tunneling machine is shown. The cutting wheels 5 are mounted on a disc or similar structure, and a conveyor 35 assists with removal of waste. Tracks 36 allow the machine to be moved, and in particular to be driven forwardly to facilitate cutting the tunnel.

In figure 12 another core drill embodiment is shown. High speed shaft 11 drives the cutting wheels 5 via gearboxes. Core samples are obtained in hollow space 40. In figures 13 and 14 a sleeve 41 is pushed into a hole formed by the drill bit as the drill bit progresses through the material in which the hole is being formed. The auger blades 25 remove waste. In this way the sleeve 41 forms a culvert or pipe as the hole is being formed. As with the embodiment of figure 7, the relative spacing or offset of the cutting wheels 5 from the central shaft 11 can be adjusted to vary the diameter or shape of the hole, and to facilitate removal of the apparatus from the lined cavity.

Referring to figure 15, another embodiment of an auger drill is shown in which a chain drive arrangement is used to turn the cutting wheels 5. In figure 15 the shaft 11 turns sprockets 46 through gearbox 45. One sprocket 46 drives a further sprocket 48 via chain 47 to turn one of the cutting wheels 5. The other sprocket 46 drives a further sprocket 50 via chain 49 to turn the other cutting wheel 5.

Referring now to figures 16 to 20, a further embodiment of a drilling apparatus according to the invention is shown, in which a pilot drill 17 is connected directly to a high speed drill shaft 11 , rotatable about a first axis 4, and rotatably mounted in a support frame 64. Preferably the shaft 11 is journaled through the support frame in one or more rotary bearings such as a sleeve bearing or rolling-element bearing, such that the support frame 64 may also rotate about the axis 4 independently from the shaft 11.

One or more cutting members, rotatable about a second axis of rotation 60 substantially orthogonal to the first axis 4, are mounted to the support frame 64. In the embodiment shown in figures 16-19, the cutting member is in the form of a cutting wheel 5 which has a plurality of cutting teeth 6. The teeth 6 may be provided as an integral part of the cutting wheel 5, or may be selectively removable or replaceable. Although a cutting wheel 5 is disclosed it will be appreciated that a variety of rotatable cutting members of differing geometries may be used.

A gear means is provided such that the rotary motion of the shaft 11 relative to the support frame 64 about the first axis 4 drives the or each cutting member about the second axis of rotation 60.

By way of example only, one or more outer beveled gears 62 may be rotatably mounted to the support frame 64 such that they are rotatable about a second axis 60, substantially orthogonal to the first axis 4, and one or more beveled gears 61 rotatable about the first axis 4 may also be provided. Preferably, one of the beveled gears 61 is fixed to the shaft 11 , such that it rotates with the same angular velocity as the shaft 11 about the axis 4. In the case of a second beveled gear 61 being provided, the second gear may be allowed to freely rotate in the opposite direction to the shaft 11 by means of a rotary bearing.

In practice, the teeth of the bevel gearing 61 engage with the complementary teeth of the bevel gears 62, such that the rotation of the shaft 11 and bevel gearing 61 about the first axis 4 cause the outer beveled gears 62 to rotate about the second axis 60. Thus, the beveled gear 61 may be used to convey the rotary movement of the shaft 11 about the first axis 4 to the outer beveled gears 62 about the second axis 60.

The support frame 64 may be rotatably driven about the first axis 4, or alternatively may be allowed to freely rotate about the shaft 11. In the latter case, the opposing rotation of the cutting members imparts a torque on the support frame 64 when the cutting members come into contact with the material being drilled, causing the support structure 64 to rotate about the first axis 4. The cutting members are located closely adjacent to the first axis and the axial force is controlled so that in use the cutting members rotate at a significantly greater speed than the speed of rotation of the apparatus about the axis 4.

Referring now to figures 20 to 22, a further embodiment of a drilling apparatus according to the invention is shown, in which the drill bit is rotatable about a first axis of rotation 4. The drill bit also includes a plurality of cutting members, wherein the cutting members are mounted on the drill bit about further axes of rotation 70 substantially orthogonal and eccentric with respect to the first axis of rotation 4. In a preferred embodiment, the further axes of rotation are offset from the first axis of rotation by a distance substantially equal to the radius of the cutting members.

In the embodiment illustrated in figures 20 to 22, the cutting members are in the form of four cutting wheels 5 which each have a plurality of cutting teeth 6. The teeth 6 may be provided as an integral part of the cutting wheel 5, or may be selectively removable or replaceable. Although a cutting wheel 5 is disclosed it will be appreciated that a variety of rotatable cutting members of differing geometries may be used.

Still referring to figures 20 to 22, the plurality of cutting members are evenly distributed about the first axis 4, whereby the angles between all adjacent cutting members are equal. Although the illustrated embodiment depicts each cutting member 5 having a distinct axis of rotation 70, it will be appreciated that a plurality of cutting members 5 rotatable about each axis of rotation 70 may be provided.

A driving means 71 is provided to drive the cutting means via a gear assembly (not shown) and a high speed shaft 72, rotatable about the first axis 4. Preferably, the cutting members 5 are rotated such that the lower portion of each cutting member rotates in an outward direction from the first axis of rotation 4, being the centre of the drill bit.

In figures 23 to 26, an embodiment is shown which is similar to that of figure 15. The gear housing 80 includes an input shaft 81 for connection to a driving apparatus. In a trial a small four stroke petrol engine of approximately 10 horsepower was used. The cutting wheels 5 comprised carbide tipped circular saw blades of approximately 200mm diameter. The gear housing 80 is externally restrained in use, for example by a handle (not shown) that can be held by an operator. Alternatively the apparatus can be mounted on a support rig or a vehicle such as a tractor or excavator. An appropriate vehicle such may have a driven coupling which can be directly connected to input shaft 81.

Input shaft 81 is directly connected to shaft 11 , and a first pair of sprockets or pulleys 82 provides a first step down ratio. Shaft 83 rotates relative to the housing 80 and a second pair of sprockets or pulleys 84 is provided between shaft 82 and shaft 3. The overall step down ratio is 8.65:1. The input shaft speed is approximately 2000 rpm, so the speed of the cutting wheels is 2000 rpm (gear box 45 has a 1 :1 ratio) and the rotational speed of shaft 3 is approximately 230 rpm.

We have found that the embodiment of figures 23 to 26 allows a hole approximately 400mm in diameter and 500mm deep to be drilled into the end-grain of a tree stump in approximately one minute.

Another practical embodiment is shown in figures 27 to 30. A gear arrangement such as that described above with reference to figures 23 to 26 may be used. In this embodiment the cutting wheels 5 comprise circular masonry saw blades. The cutting wheels are approximately 125mm in diameter. The step down ratio is approximately 13.42:1 , so at an input shaft speed of 2000 rpm (being the cutting wheel speed), the body 3 rotates at approximately 149 rpm. The apparatus was tested by engaging input shaft 81 in the chuck of a 750 Watt electric hand drill. A 125mm diameter hole approximately 50mm deep was drilled through a masonry block in approximately 2 minutes.

The process is portable, which means holes can be made on site. Some potential uses are concrete drilling by construction companies, builders or handy-men, directional drilling for the installation of services such as optical fibre, rock drilling in mines, foundation drilling, underground tunnelling, wooden stump grinding.

Removal of the resultant removed material may be via vacuum, or flushing with air water or oil, or via an auger removal system.

The cutting members 5 can be moved in a rotational motion that is not circular i.e. they may be eccentrically mounted to provide a "wobble" motion is a desired plane to improve efficiency or speed of material removal if required. Alternatively they may be mounted on a further axis so that the abrasive or cutting surfaces describe a more complex movement for some applications. Also, the support 3 may be moved in a more complex motion, or about a further axis, for example moving so that a hole or cavity is formed which is larger than that formed by rotation of the apparatus about axis 4.

The drilling method and apparatus described provides numerous advantages (although these may not necessarily be present in all embodiments). One advantage of this process is that high accuracy may be achieved because the material removal reaction forces are minimized through the high rate micro cutting or grinding resulting from the relatively higher speed of the cutting member relative to the speed of rotation of the first axis. This can be important when making a hole in harder materials such as rock, concrete, timber or steel. A further result of this is that the object being penetrated is subjected to lesser forces compared to traditional drilling operations, resulting in less disturbance and better accuracy being achievable. Lesser disturbance can also have safety advantages.

Another advantage is that the amount of energy required to perform the operation is reduced. This is important in applications where space is at a premium, such as tunneling or directional drilling. In these applications there are space limitations on the size of cutter drives that can be fitted. Also, in this type of operation the material removal process is often remote from the base of operation and transporting large amounts of energy to the operation is expensive or impractical - for instance the voltage drop in electrical cables or flow friction losses in hydraulic hoses - so that a more energy effective operation is advantageous.

From the foregoing it will be seen that cutting, drilling or grinding apparatus and methods are provided which allow such operations to be performed quickly and efficiently with minimal torque being required to turn the drill bit. This has the advantage of reducing mechanical loads on machinery and thus also reducing maintenance requirements. Although the invention has been described above with particular reference to drilling and excavating operations, the apparatus and methods are also applicable to other cutting or grinding operations, such as tree mulching, or machining machinery parts, or shaping objects, for example "facing" a rock surface or metal surface.

Throughout this document the word "comprise" and variations thereof is intended to be interpreted in an inclusive sense. Where in the foregoing description reference has been made to specific components or integers of the invention having known equivalents, then such equivalents are herein incorporated as if individually set forth.

Although this invention has been described by way of example and with reference to possible embodiments thereof, it is to be understood that modifications or improvements may be made thereto without departing from the scope of the invention.

Claims

1. Cutting drilling or grinding apparatus including a body rotatable about a first axis of rotation and a cutting member to cut grind or abrade a material to be removed by the apparatus, the cutting member being rotatably mounted on the body about a second axis of rotation, wherein the second axis of rotation is substantially orthogonal with respect to the first axis of rotation, driving means to rotate the cutting member about the second axis of rotation while also rotating the body about the first axis of rotation, and wherein the driving means is adapted to rotate the cutting member about the second axis of rotation at a substantially greater rotational speed than the rotational speed of the body about the first axis of rotation.

2. Apparatus as claimed in claim 1 wherein the area traversed by a cutting surface of the cutting member in one revolution of the cutting member is substantially less than the area traversed by the cutting surface in one revolution of the body.

3. Apparatus as claimed in claim 1 or claim 2 wherein rotation of the cutting member imparts minimal torque about the first axis.

4. Apparatus as claimed in any one of the preceding claims wherein the axis of rotation of the cutting member is eccentric with respect to the first axis.

5. Apparatus as claimed in any one of the preceding claims wherein the apparatus includes an adjustment means to adjust the position of the second axis of rotation relative to the first axis.

6. Apparatus as claimed in any one of the preceding claims wherein a plurality of cutting members are provided.

7. Apparatus as claimed in any one of the preceding claims wherein the or each cutting member is driven by a gear assembly.

8. Apparatus as claimed in any one of claims 1 to 6 wherein the or each cutting member is driven hydraulically.

9. Apparatus as claimed in any one of the preceding claims wherein the or each cutting member comprises a cutting blade.

10. A drilling assembly including apparatus as claimed in any one of the preceding claims wherein the drill bit is mounted on a support member.

11. A drilling assembly as claimed in claim 10 wherein the support member comprises a drill shaft.

12. A drilling assembly as claimed in claim 10 or claim 11 wherein the body is rotated about the first axis relative to the support member.

13. A drilling assembly as claimed in claim 10 or claim 11 wherein the body is rotated about the first axis by rotation of the support member.

14. A drilling method, the method including the step of rotating a body of a cutting, drilling or grinding apparatus about a first axis of rotation while rotating a cutting member rotatably mounted on the body about a second axis of rotation at a substantially greater rotational speed than the rotational speed of the body about the first axis of rotation, the second axis of rotation being substantially orthogonal to the first axis of rotation, such that the cutting member removes material from an object to thereby remove material from the object. .

15. A method as claimed in claim 14 including moving the body axially along the first axis of rotation in a direction toward the object to form the hole or cavity.

16. A method as claimed in claim 14 or claim 15 including the step of varying the position of the second axis relative to the first axis to varying a dimension of a hole or cavity to be formed in the object.

17. A method as claimed in any one of claims 14 to 16 including the step of moving a sleeve behind the body as the apparatus forms a hole or cavity in the object.

18. Apparatus substantially as herein described with reference to any embodiment shown in the drawings.

19. A method substantially as herein described with reference to any embodiment shown in the drawings.