GB2483694A

GB2483694A - Cutting tool assembly

Info

Publication number: GB2483694A
Application number: GB1015538.0A
Authority: GB
Inventors: Donald Arthur Lee
Original assignee: BRYANT SYMONS TECHNOLOGIES Ltd
Current assignee: BRYANT SYMONS TECHNOLOGIES Ltd
Priority date: 2010-09-17
Filing date: 2010-09-17
Publication date: 2012-03-21
Anticipated expiration: 2030-09-17
Also published as: GB201015538D0; GB2483694B

Abstract

The cutting tool assembly 1 may be mounted to a rotary flycutting disc or head of a suitable machine e.g. an aircraft window refurbishing machine. The assembly includes a body or housing 2 that is releasably securable to the fly cutting disc. A cutting tool 6 is pivotally located within an opening provided in the body. A clamp block 28 is secured to the body by means of a clamping screw 32. Selective linear movement of the clamp block 28 caused by tightening the clamping screw 32 fixedly secures the body 2 to the flycutting disc and fixedly secures the cutting tool 6 to the body in a selected orientation when the cutting tool is in use. A flycutting disc may include a number of cutting tool assemblies, each located at a different radius from the centre of the disc.

Description

TITLE

Cutting tool assemblies

DESCRIPTION

Technical Field

The present invention relates to cuffing tool assemblies, and in particular to those that can be used for diamond machining.

The cuffing tool assemblies can be releasably mounted to the rotary flycutting disc or head of any suitable machine. In one particular aspect of the invention the flycuffing disc forms part of an aircraft window refurbishment machine which is used to achieve a fine surface finish on acrylic aircraft windows.

Summay of the Invention The present invention provides an improved cuffing tool assembly comprising: a body that is releasably securable to a rotary flycuffing disc; a cuffing tool that is pivotally located within an opening provided in the body; and a clamp block that is secured to the body by a clamping screw and where selective linear movement of the clamp block in a first direction (e.g. a clamping or tightening direction) relative to the body, under the action of the clamping screw, fixedly secures the body to the flycuffing disc and fixedly secures the cuffing tool to the body in a selected orientation when the cutting tool is in use.

The cuffing tool is preferably removable and includes a rear part which defines a pair of adjustment shoulders and a front part, which typically extends beyond the body, on which a tool element is provided. It will be readily appreciated that any use of the terms like "front", "rear" and "rearwardly" etc. are not intended to be limiting but are used generally to refer to parts of the cuffing tool assembly when in a use position, e.g. when installed in a flycuffing disc or head, and on the basis that the front of the cuffing tool assembly will normally face a workpiece.

The front and rear parts of the cutting tool can be integrally formed or formed as separate parts and then secured together, optionally in a way that allows the parts to be selectively released when the tool element needs to be replaced.

The tool element is preferably a diamond tool, Diamond tools are known to provide a very fine finish arid are durable and hard wearing. The cuffing edge on a diamond tool is normally arcuate and the front part of the cutting tool on which the tool element is provided is preferably designed to be pivotable through an arc that is comparable to the arcuate cutting edge of the diamond tool. In a conventional tool assembly the diamond tool is mounted in a rigid setting and once the cutting face has become worn then it is no longer useable and has to be replaced. With the present invention the cuffing tool can be selectively pivoted relative to the body so that more of the cuffing edge, and most preferably substantially all of it, can be utilised. In other words, once part of the cuffing edge has become worn then the cutting tool can be pivoted relative to the body so that another part of the cutting edge can be used. This increases the lifetime of a single diamond tool and leads to considerable cost savings.

The ability to pivot the cutting tool within the body of the cutting tool assembly also provides additional flexibility when positioning the tool element. The tool element can be fixed to the cutting tool by means of a indexable insert of the type that is sometimes used for tungsten carbide tooling.

Once substantially all of the cutting edge of the tool element has become worn then a new cuffing tool can be inserted into the cutting tool assembly by removing the clamp block. If the front and rear parts of the cutting tool are secured together in a way that allows them to be selectively released then only the front part of the cutting tool needs to be replaced.

The orientation of the cutting tool relative to the body can be selectively adjusted by a pair of adjustment screws received in threaded bores provided in the body. Each adjustment screw can be selectively rotatable to contact a respective one of the adjustment shoulders provided at the rear part of the cutting tool to cause the cutting tool to pivot relative to the body. It will be readily appreciated that rotating an adjustment screw in a first sense will cause it to move in a linear direction towards the rear of the body until it contacts the facing adjustment shoulder. Further rotation of the adjustment screw in the first sense will then move the facing adjustment shoulder towards the rear of the body causing the cutting tool to pivot about a pivot point.

Rotating the adjustment screw in a second, opposite, sense will cause it to move in a linear direction away from the rear of the body to provide clearance between the adjustment screw and the facing adjustment shoulder. Such clearance may be necessary before the cutting tool can be pivoted in a particular ense by rotating the other adjustment screw. By selective rotation of the adjustment screws it is therefore possible to pivot the cutting tool relative to the body until a selected orientation is achieved. That selected orientation is preferably maintained when the cutting tool assembly is in use by making sure that both adjustment screws are in contact with their facing adjustment shoulders. However, selective linear movement of the clamp block towards the rear of the cutting tool assembly along a surface that is inclined relative to a longitudinal axis of the cutting tool assembly exerts a radial clamping force against a surface of the cutting tool to fixedly secure the cutting tool in the selected orientation. The inclined surface along which the clamp block slides can be a facing surface of the cutting tool that is mounted in the opening of the body in such a way as to be inclined relative to the longitudinal axis of the cutting tool assembly.

The clamping screw can be received in a threaded bore in the body and can pass through an opening provided in the clamp block. The opening is preferably sized to allow the clamping block to move radially outwardly when the clamp block moves towards the rear of the cuffing tool assembly along the inclined surface. In other words, the narrowest part of the opening preferably has a diameter that is larger than the diameter of the clamping screw to permit the clamp block to move in the radial direction as the clamping screw is tightened and the clamp block slides along the inclined surface. The inclined surface translates part of the axial force exerted on the clamp block by the clamping screw as it is tightened into radial inward and outward clamping forces that act simultaneously to secure the cutting tool within the body arid the body within a bore provided in a flycutting disc as discussed in more detail below.

The clamping screw, the threaded bore in the body in which it is received and the opening in the clamp block can be aligned with the longitudinal axis of the cutting tool assembly, with an axis of the opening in the body in which the cutting tool is received (i.e. aligned with the inclined surface along which the clamp block slides) or with any other suitable axis that facilitates useful operation of the cutting tool assembly.

The cutting tool assembly can be mounted to the flycutting disc or head of a machine.

The flycutting disc can include a bore in which the body of the cutting tool assembly is received. The bore will be sized and shaped to closely accommodate the body of the cutting tool assembly and may optionally have a substantially cylindrical surface which allows the cutting tool assembly to pivot or rotate within the bore relative to the flycutting disc. Selective linear movement of the clamp block in the first direction relative to the body, under the action of the clamping screw, increases the outer diameter of the cutting tool assembly in the region of the clamp block as the clamp block moves along the inclined surface and this exerts a clamping force against a surface of the flycutting disc, e.g. against a region of the substantially cylindrical surface of the bore facing the outer surface of the clamp block. The clamping force also moves the cutting tool assembly in the radial direction until a region of the body that is diametrically opposite the clamping block is bought into contact with a facing region of the substantially cylindrical surface of the bore. In other words, the cutting tool assembly is preferably held securely in position within the bore when the flyeutting disc is in use by friction contact with the substantially cylindrical surface of the bore at two separate locations by the application of the clamping force, firstly in the region of the clamp block and secondly in a region that is diametrically opposed to the clamp block.

A slewing or adjustment ring can be releasably secured to the flycutting disc, e.g. by means of a fixing screw. The adjustment ring is used to secure the body of the cutting tool assembly to the flycutting disc although it will be readily appreciated that the flycutting disc will not be used until the cutting tool assembly is held securely in position by the clamping force that is applied by the clamp block. The fixing screw can pass through a threaded or non-threaded bore in the flycutting disc and is then received in a threaded bore in the adjustment ring.

The adjustment ring is preferably not able to rotate relative to the flycutting disc.

The body of the cutting tool assembly can be releasably secured to the adjustment ring and can be pivotable relative to the adjustment ring (i.e. within the bore provided in the flycutting disc) until it is fixedly secured to the adjustment ring by at least one fixing screw. For example, the body of the cutting tool assembly can be releasably secured to the adjustment ring by at least one fixing screw passing through an arcuate circumferential slot in the adjustment ring that allows limited pivotable movement between the body of the cutting tool assembly and the adjustment ring.

The at least one fixing screw can be received in a threaded bore provided in a rear surface of the body of the cutting tool assembly. A pair of fixing screws will often be provided, each passing through a separate arcuate circumferential slot in the adjustment ring and being received in threaded bore provided in the rear surface of the body of the cutting tool assembly. The angular position of the cutting tool assembly relative to the adjustment ring relative can be selected while the at least one fixing screw is slackened off and then fixed by tightening the at least one fixing screw.

Since the adjustment ring can preferably only be mounted to the flycutting disc in a particular orientation and cannot rotate relative to the flycutting disc then it will be readily appreciated that selecting the angular position of the cutting tool assembly relative to the adjustment ring will also determine or select a particular angular position or orientation for the cutting tool assembly relative to the flycutting disc itself.

The adjustment ring can include a central opening for receiving a rearwardly extending shaft part of the body. The rearwardly extending shaft part may also be received in a corresponding aligned opening in the base of the bore that is provided in the flycutting disc.

The distance between the tool element on the front part of the cutting tool and a surface of the flycutting disc can be selectively adjusted, e.g. by moving the cutting tool assembly (and, optionally, the adjustment ring) linearly within the bore provided in the flycutting disc. This can be achieved by the use of a positioning screw that is received in a threaded bore in the flycutting disc and which acts against a rear surface of the adjustment ring, for example. The lateral position of the cutting tool assembly within the bore can then be adjusted by rotating the positioning screw. Any fixing screw that is used to secure the adjustment ring to the flycutting disc may need to be slackened off to allow such lateral positioning to take place and then re-tightened.

It will be clear from the above description that the cutting tool assembly, and in particular the tool element, can be placed in a selected orientation relative to the flycutting disc by adjusting the angular (rotational) andlor lateral position of the cutting tool assembly within the bore. Such movement is in addition to the pivotable movement of the cuffing tool relative to the body of the cuffing tool assembly and provides considerable flexibility. Once the various adjustment steps have been carried out, selective linear movement of the clamp block in the first direction towards the rear of the cutting tool assembly, under the action of the clamping screw, preferably exerts a radial clamping force against a surface of the flycutting disc, e.g. against the substantially cylindrical surface of the bore provided in the flycutting disc, to fixedly secure the body to the flycutting disc in the selected orientation.

The orientation of the cuffing tool assembly relative to the flycutting disc will generally be dependent on the workpiece to be machined and will not normally require constant adjustment.

Once the cutting tool assembly has been properly fixed within the bore of the flycutting disc by the clamp block then machining of the workpiece can commence.

During machining then the orientation of the cutting tool (and hence the tool element) relative to the body of the cutting tool assembly can be adjusted as the cutting edge becomes worn. This adjustment is carried out by the adjustment screws and the clamping screw which can be easily accessed from the front of the flycutting disc or head. In most cases this means that the orientation of the cutting tool can be conveniently adjusted during the machining process without having to remove the flycutting disc and without having to adjust the orientation of the complete cutting tool assembly relative to the flycutting disc.

A flycutting disc can incorporate a plurality of cutting tool assemblies. In this case it would be normal for each cutting tool assembly to be located in a bore provided at a different radius from the centre of the flycutting disc. However, each cutting tool assembly may also be located at the same radius from the centre of the flycutting disc with staggering of the tool elements being achieved by offsetting the cutting tools within the body of the respective cutting tool assemblies. The cutting tool assemblies may be adapted to provide different grades of cut. For example, if the rotary flycutting disc has three separate cutting tool assemblies then they may provide a rough, medium and then final, fine, cut for each pass of the workpiece.

The rotary flycutting disc may form part of an aircraft window refurbishment machine that is used to refurbish acrylic aircraft windows to remove surface crazing'.

However, it will be readily appreciated that the flycutting disc may have other possible uses.

Drawijgs Figure 1 is a front perspective view showing a cutting tool assembly according to the present invention with an adjustment ring; Figure 2 is a rear perspective view of the cutting tool assembly and adjustment ring of Figure 1; Figure 3 is a top view of the cutting tool assembly of Figure 1 without the adjustment ring; Figure 4 is a lower perspective view of the cutting tool assembly of Figure 1 without the adjustment ring; Figure 5 is a side view of the cutting tool assembly of Figure 1 without the adjustment ring; Figure 6 is a cross section view taken along the line A-A of Figure 5 without the adjustment ring; Figure 7 is a front view of the cutting tool assembly of Figure 1 mounted within a flycutting disc; Figure 8 is a cross section view taken along the line B-B of Figure 7; Figure 9 is a perspective view showing how the cutting tool assembly is mounted within a flycutting disc; Figure 10 is a top view of the cutting tool assembly of Figure 1 with the clamp block and cutting tool removed; and Figure 11 is a top view of the cuffing tool assembly of Figure 1 with the clamp block removed.

A cuffing tool assembly 1 includes a machined or cast metal housing or body 2. The body 2 has a generally cylindrical outer surface and defines an opening 4 (Figures 6, and 11) in which a cuffing tool 6 is freely located.

The cuffing tool 6 is most clearly seen in Figures 6, 8 and 11 and includes a front part 8 on which a diamond tool 10 is rigidly mounted, and a rear part 12. The rear part 12 has an arcuate surface 14 that terminates at adjustment shoulders 16a, 16b. The arcuate surface 14 is in sliding contact with a corresponding arcuate seating surface at a rear part of the opening 4. A pivot pin (not shown) may be located in a bore 21 provided in the body 2 and is received in a central opening 23 in the rear part 12 of the cuffing tool 6. The pivot pin (not shown) is an optional feature and serves to retain the cuffing tool 6 in its proper position within the opening 4, preferably with its rear arcuate surface 14 in sliding contact with the arcuate seating surface 20, particularly in the event that the adjustment screws 24a, 24b described below are not in contact with the adjustment shoulders 16a, 16b of the cuffing tool.

A pair of threaded bores 22a, 22b are provided in a front part of the body 2 and are aligned with the adjustment shoulders 16a, 1 6b when the cuffing tool 6 is located in the opening 4. A pair of adjustment screws (or grub screws) 24a, 24b are received in the threaded bores 22a, 22b. Rotation of the adjustment screws in a first sense will cause the adjustment screws 24a, 24b to move towards the adjustment shoulders 1 6a, 16b and rotation of the adjustment screws in a second, opposite, sense will cause the adjustment screws to move away from the adjustment shoulders. The adjustment screws 24a, 24b are used to pivot the cutting tool 6 within the opening 4. For example, the first adjustment screw 24a can be rotated using a suitable tool in the first sense until its end comes into contact with the facing adjustment shoulder l6a of the cutting tool 6. Further rotation of the first adjustment screw 24a in the first sense will cause the cutting tool 6 to slide against the arcuate seating surface 20 and pivot about a pivot point 26 as the first adjustment shoulder 1 6a moves towards the rear of the body 2 and the second adjustment shoulder 16b moves towards the front of the body.

When viewed from the front, the front part of the cutting tool 6 will pivot towards the left. Rotating the second adjustment screw 24b in the first sense so that the second adjustment shoulder 16b moves towards the rear of the body 2 will make the front part of the cutting tool 6 pivot towards the right. It will be readily appreciated that it may be necessary to provide a clearance between an adjustment screw and the aligned adjustment shoulder before the cutting tool 6 can be pivoted. For example, if both adjustment screws are in contact with the aligned adjustment shoulders then it will be necessary to rotate the second adjustment screw 24b in the second sense so that its end moves away from the second adjustment shoulder 1 6b before the front part of the cutting tool 6 can be pivoted towards the left by turning the first adjustment screw 24a in the first sense.

A clamp block 28 of machined or cast metal includes a non-threaded opening 30 for receiving a clamping screw 32. The clamping screw 32 extends through the opening and is received in an aligned threaded bore 34 (Figure 8) provided in a rear part of the body 2. A bottom surface of the clamp block 28 is in sliding contact with an upper surface of the cuffing tool 6. The bottom surface of the clamp block 28 and the upper surface of the cutting tool 6 are both inclined relative to the opening 30 in the clamp block and the threaded bore 34. The hex head 32a of the clamping screw 32 is received in a front part 36 of the opening 30 having a larger diameter while the threaded shaft 32b passes through a narrower central part 38 of the opening having a smaller diameter. The diameter of the narrower central part 38 is slightly larger than the threaded shaft 32b of the clamping screw 32 such that the clamp block 28 can move in the radial direction as it slides along the inclined upper surface of the cutting tool 6. The clamp block 28 is axially spaced apart from the body 2 by a small gap 27 and in this position the radially outer surface 40 of the clamp block is radially aligned with, and is essentially a continuation of, the substantially cylindrical outer surface of the body 2 of the cutting tool assembly 1. The clamp block 28 defines an overall diameter that is the same as, or even slightly less than, the diameter of the remainder of the body.

When the hex head 32a is properly received in the front part 36 of the opening 30 then rotation of the clamping screw 32 in a first sense (i.e. tightening of the clamping screw) forces the clamp block 28 towards the rear of the body 2 to close the small gap 27. The inclined surfaces of the clamp block 28 and the cutting tool 6 means that the clamp block will exert a radial clamping force on the cutting tool as it moves towards the rear of the body 2, i.e. the cutting tool is effectively clamped between the clamp block and the part of the body that supports and locates the cutting tool. This clamping force is used to maintain the cutting tool 6 in the selected orientation relative to the body 2 of the cutting tool assembly 1 during use.

The clamp block 28 will move radially outwardly at it slides axially along the inclined upper surface of the cutting tool 6 towards the rear of the body 2, such radial movement being permitted by the clearance between the narrower central part 38 of the opening 30 and the clamping screw 32. The radial outward movement of the clamp block 28 increases the overall diameter of the cutting tool assembly 1 in the region of the clamp block 28 and exerts a radial clamping force on a facing cylindrical surface 29 of a bore 31 that is provided in a rotary flycutting disc 33. This clamping force is used to maintain the body 2 in the selected orientation relative to the flycutting disc 33 during use. Turning the clamping screw 32 in the opposite sense allows the clamp block 28 to move away from the rear of the body 2 to release the clamping forces that are exerted against the cutting tool 6 and the flycutting disc 33.

An adjustment ring 100 of machined or cast metal is releasably secured to the flycutting disc 33 by a fixing screw 102. The fixing screw 102 passes through a bore in the flycutting disc 33 (Figure 8) and is received in an off-centre threaded bore 104 provided in the adjustment ring 100. The bore 35 may have a larger diameter than the fixing screw 102 to accept, during temporary removal of the fixing screw, an optional removal screw or other tool which can be used to push the cuffing tool assembly 1 out of the bore 31 in the flycutting disc 33. A dowel 112 is located in a non-threaded bore 114 in the adjustment ring 100 and in a corresponding aligned non-threaded bore 37 that is provided in the flycutting disc 33 so that the adjustment ring cannot rotate relative to the flycutting disc. The adjustment ring 100 includes a central opening 110 that is sized to receive a rearwardly extending shaft part 42 of the body of the cutting tool assembly 1. The shaft part 42 also extends into a corresponding aligned opening 39 in the base of the bore 31 provided in the flycutting disc 33 as shown in Figures 8 and 9. The lateral position of the adjustment ring 100 arid the cuffing tool assembly 100 within the bore 31 can be selected by rotating a positioning screw (or grub screw) 116 which is received in a threaded bore 41 at the base of the bore and which acts against a rear surface of the adjustment ring 100. In some cases it may be necessary to slacken off the fixing screw 102 before the adjustment ring 100 can be moved away from the base of the bore 31, i.e. to the bring the cuffing tool closer to a workpiece.

The cuffing tool assembly I is fixed to the adjustment ring 100 by a pair of fixing screws 106a, 106b which pass through arcuate circumferential slots lO8a, 108b provided in the adjustment ring and are received in threaded bores 44 provided in the rear part of the body 2. Although the cutting tool assembly 1 is fixed to the adjustment ring 100 by the fixing screws lO6a, 1 06b it is still able to pivot relative to the adjustment ring (and hence also to the rotary flycutting disc 33) to a limited extent provided by the sliding movement of the fixing screws within the arcuate circumferential slots 1 08a, I 08b while the fixing screws are slackened off. The angular position of the cuffing tool assembly 1 relative to the adjustment ring 100 is fixed by tightening the fixing screws 1 06a, 1 06b before the assembled parts are inserted into the bore 31 of the flycutting disc 33. the cutting tool assembly 1 is temporarily secured to the flycutting disc 33 by means of the adjustment ring 100 and is then secured properly and directly to the flycutting disc when the clamp block 28 is moved towards the rear of the body 2 by the clamping screw 32 so that the clamping -12 -force is exerted on the cylindrical surface 29 of the bore 31 in which the cutting tool assembly is located.

In use the cutting tool assembly I is fixed to the adjustment ring 100 in a desired angular position by rotating one component relative to the other while the fixing screws 1 06a, 1 06b are slackened off. The fixing screws lOôa, lO6b slide in the circumferential slots lO8a, 108b provided in the adjustment ring 100 which limits the extent of the relative rotation between cutting tool assembly 1 and the adjustment ring 100. When the correct angular position has been selected the fixing screws 1 06a, 106b are tightened to secure the two components together. The cutting tool assembly 1 and the secured adjustment ring 100 are then inserted into the bore 31 in the ulycutting disc 33. The adjustment ring 100 (and hence the cutting tool assembly 1) is secured to the flycutting disc 33 by means of the fixing screw 102 and the dowel 112.

It will be readily appreciated that the adjustment ring 100 can only be secured to the flycutting disc 33 in a particular orientation that is determined by the correct alignment between the bores 35 and 37 in the flycutting disc and the bores 104 and 114 in the adjustment ring, respectively. Since the adjustment ring 100 is secured to the rear of the cutting tool assembly I by the fixing screws 106a, 106b then this means that the orientation of the cutting tool assembly relative to the flycutting disc 33 is also fixed once the two components are properly inserted into the bore 31 and the fixing screw 102 is tightened. The lateral position of the adjustment ring 100 and the cutting tool assembly I within the bore 31 can be adjusted by rotating the positioning screw 116 as described above. By carrying out these adjustment steps the desired orientation of the cutting tool assembly 1 relative to the flycutting disc 33 is manually selected or adjusted by a user.

The desired orientation of the cutting tool 6 relative to the body 2 of the cutting tool assembly I is selected using the adjustment screws 24a, 24b. This adjustment of the cutting tool 6 will normally be done after the cutting tool assembly 1 has been inserted into the bore 31 but it can also be done before. Finally, the clamp block 28 is tightened using the clamping screw 32 to properly secure the cutting tool assembly 1 -13 -to the flycutting disc 33 and to secure the cutting tool 6 to the body 2 of the cutting tool assembly 1.

When the diamond tool 10 has become worn, the clamp block 28 can be released by rotating the clamping screw 32 in the opposite sense and the cutting tool 6 can be pivoted using the adjustment screws 24a, 24b to select a different part of the diamond tool 10. It will be readily appreciated that very precise pivoting movement of the cutting tool 6 in the desired direction can be achieved by rotating the adjustment screws 24a, 24b. The clamp block 28 is tightened and machining can recommence as before. It will be readily appreciated that both the clamping screw 32 and the adjustment screws 24a, 24b are easily accessible from the front of the cutting tool assembly 1 so the adjustment of the cutting tool 6 can be done while the cutting tool assembly remains in the bore 33 and fixed to the flycutting disc 33 by the adjustment ring 100.

When a cutting tool 6 needs to be replaced that it can be removed from the body 2 by removing or releasing the clamp block 28 and a new cutting tool can be installed.

Claims

-14 -CLAIMS1. A cutting tool assembly comprising: a body that is releasably securable to a rotary flycutting disc; a cutting tool that is pivotally located within an opening provided in the body; and a clamp block that is secured to the body by a clamping screw and where selective linear movement of the clamp block in a first direction relative to the body, under the action of the clamping screw, fixedly secures the body to the flycutting disc and fixedly secures the cutting tool to the body in a selected orientation when the cuffing tool is in use.
2. A cutting tool assembly according to claim 1, wherein the clamp block moves radially outwardly along a surface that is inclined to a longitudinal axis of the cutting tool assembly when it is moved linearly in the first direction.
3. A cutting tool assembly according to claim 2, wherein the inclined surface is defined by a surface of the cutting tool.
4. A cutting tool assembly according to any preceding claim, wherein the cutting tool includes a rear part which defines a pair of adjustment shoulders and a front part on which a tool element is provided.
5. A cutting tool assembly according to claim 4, wherein the orientation of the cutting tool is selectively adjusted by a pair of adjustment screws received in threaded bores in the body, each adjustment screw being selectively rotatable to contact a respective one of the adjustment shoulders of the rear part of the cutting tool to cause the cutting tool to pivot relative to the body.
6. A cuffing tool assembly according to any preceding claim, wherein the clamping screw is received in a threaded bore in the body.

-15 -
7. A cutting tool assembly according to any preceding, wherein the clamping screw passes through an opening provided in the clamp block.
8. A flycutting disc comprising at least one cutting tool assembly according to any preceding claim.
9. A flycutting disc according to claim 8, wherein the flycutting disc includes a bore in which the body of the cutting tool assembly is received.
10. A flycutting disc according to claim 8 or claim 9, further comprising an adjustment ring releasably secured to the flycutting disc.
11. A flycutting disc according to claim 10, wherein the body of the cutting tool assembly is releasably secured to the adjustment ring and is pivotable relative to the adjustment ring until it is fixedly secured to the flycutting disc by the clamp block.
12. A flycutting disc according to claim 11, wherein the body of the cuffing tool assembly is releasably secured to the adjustment ring by at least one fixing screw passing through an areuate circumferential slot in the adjustment ring that allows limited pivotable movement between the body of the cuffing tool assembly and the adjustment ring.
13. A flycutting disc according to claim 12, wherein the at least one fixing screw is received in a threaded bore provided in a rear surface of the body of the cuffing tool.
14. A flycutting disc according to any of claims 10 to 13, wherein the adjustment ring includes a central opening for receiving a rearwardly extending shaft part of the body.
15, A flycutting disc according to claim 14, wherein the rearwardly extending shaft part of the body further extends through an opening in the flycutting disc.
16. A flycutting disc according to any of claims 8 to 15, wherein a tool element is provided on a front part of the cutting tool and the distance between the tool element and a surface of the flycutting disc can be selectively adjusted.
17. A flycutting disc according to any of claims 8 to 16, wherein selective linear movement of the clamp block towards the rear of the cutting tool assembly, under the action of the clamping screw, exerts a clamping force against a surface of the flycutting disc to fixedly secure the body to the flycutting disc.
18. A flycutting disc comprising a plurality of cutting tool assemblies according to any of claims 1 to 7, the cutting tool of each cutting tool assembly being located at a different radius from the centre of the flycutting disc.
19. An aircrafl window refurbishment machine incorporating a flycutting disc according to any of claims 8 to 18.
20. A cutting tool assembly substantially as herein described and with reference to the drawings.Amendments to the claims have been made as follows:CLAIMS1. A cutting tool assembly comprising: a body that is releasably securable to a rotary flycutting disc; a cutting tool that is pivotally located within an opening provided in the body; and a clamp block that is secured to the body by a clamping screw and where selective linear movement of the clamp block in a first direction relative to the body, under the action of the clamping screw, fixedly secures the body to the flycutting disc and fixedly secures the cutting tool to the body in a selected orientation when the cuffing tool is in use.2. A cutting tool assembly according to claim 1, wherein the clamp block moves radially outwardly along a surface that is inclined to a longitudinal axis of the cutting tool assembly when it is moved linearly in the first direction.3. A cutting tool assembly according to claim 2, wherein the inclined surface is defined by a surface of the cutting tool.4. A cutting tool assembly according to any preceding claim, wherein the cutting tool includes a rear part which defines a pair of adjustment shoulders and a front part on which a tool element is provided.5. A cutting tool assembly according to claim 4, wherein the orientation of the cutting tool is selectively adjusted by a pair of adjustment screws received in threaded bores in the body, each adjustment screw being selectively rotatable to contact a respective one of the adjustment shoulders of the rear part of the cutting tool to cause the cutting tool to pivot relative to the body.6. A cuffing tool assembly according to any preceding claim, wherein the clamping screw is received in a threaded bore in the body.7. A cutting tool assembly according to any preceding claim, wherein the clamping screw passes through an opening provided in the clamp block.8. A flycutting disc comprising at least one cutting tool assembly according to any preceding claim.9. A flycutting disc according to claim 8, wherein the flycutting disc includes a bore in which the body of the cutting tool assembly is received.10. A flycutting disc according to claim 8 or claim 9, further comprising an adjustment ring releasably secured to the flycutting disc.11. A flycutting disc according to claim 10, wherein the body of the cutting tool assembly is releasably secured to the adjustment ring and is pivotable relative to the adjustment ring until it is fixedly secured to the flycutting disc by the clamp block.12. A flycutting disc according to claim 11, wherein the body of the cutting tool assembly is releasably secured to the adjustment ring by at least one fixing screw passing through an arcuate circumferential slot in the adjustment ring that allows limited pivotable movement between the body of the cutting tool assembly and the adjustment ring.13. A flycutting disc according to claim 12, wherein the at least one fixing screw is received in a threaded bore provided in a rear surface of the body of the cutting tool. * S *5S.S* 5* SS * 14. A Ilycutting disc according to any of claims 10 to 13, wherein the adjustment ring includes a central opening for receiving a rearwardly extending shaft part of the body.15, A flycutting disc according to claim 14, wherein the rearwardly extending shaft part of the body further extends through an opening in the flycutting disc.16. A flycutting disc according to any of claims 8 to 15, wherein a tool element is provided on a front part of the cutting tool and the distance between the tool element and a surface of the flycutting disc can be selectively adjusted.17. A flycutting disc according to any of claims 8 to 16, wherein selective linear movement of the clamp block towards the rear of the cutting tool assembly, under the action of the clamping screw, exerts a clamping force against a surface of the flycutting disc to fixedly secure the body to the flycutting disc.18. A flycutting disc comprising a plurality of cutting tool assemblies according to any of claims 1 to 7, the cutting tool of each cutting tool assembly being located at a different radius from the centre of the flycutting disc.19. An aircrafl window refurbishment machine incorporating a flycutting disc according to any of claims 8 to 18.20. A cutting tool assembly substantially as herein described and with reference to the drawings.