GB2401335A

GB2401335A - Machine tool chuck provided for receiving a supply of pressurised fluid

Info

Publication number: GB2401335A
Application number: GB0329163A
Authority: GB
Inventors: John Charles Baker
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-05-03
Filing date: 2003-12-17
Publication date: 2004-11-10
Anticipated expiration: 2023-12-17
Also published as: GB2401335B; GB0310252D0; GB0329163D0

Abstract

For the machining of material by means of an elongate cutting tool 100 which rotates relative to the material a chuck 10 is provided for supporting the cutting tool and annular orifice means 101, which may be associated with the chuck 10, is provided for receiving a supply of pressurised fluid and causing said pressurised fluid to flow from the orifice 101 in the form of a fluid sleeve in a direction substantially parallel with the major axis of the elongate cutting tool 100 in a direction towards the workpiece, the annular orifice 101 surrounding a part of the length of the cutting tool 100 which has a substantially smooth outer surface.

Description

240 1 335 Machine Tool Chuck This invention relates to a machine tool

chuck, such as a collet type chuck, for use in machining operations, and in particular but not exclusively the machine drilling or milling of metal. The invention relates also to a method of machining, and to an adapter for enabling a chuck of a type known per se to be used in accordance with the method of the invention.

The successful machining of many different types of materials, notably, but not limited to, metallic materials, commonly requires the supply of a liquid to cool and/or lubricate the action of the cutting tool.

One technique employed for supply of liquid when drilling is to utilise a carbide drill of a kind which incorporates coolant "through-passages" that extend lengthwise from the secured end of the drill to the front, cutting end. The chuck comprises a hollow body which is fed with pressurised liquid that then flows lengthwise, through the drill, to exit at the region of the cutting end. A sealing washer is provided to inhibit unwanted leakage of liquid via the slits of a spring type collet.

Another and more commonly employed technique is to arrange an external pipe or hose to direct a jet of coolanVlubricant liquid to the drill and/or the The use of a carbide drill with internal fluid passages generally facilitates effective cooling and lubrication, but suffers the disadvantage of cost, the drill typically being in the order of ten times more expensive than that of a conventional high speed or cobalt high speed drill that is externally cooled and lubricated.

In contrast, the lower cost high speed steel drill, without internal fluid passages,requires relatively frequent removal for sharpening. Furthermore, ! a significant proportion of liquid directed at the drill and/or the work piece tends to be thrown out radially by the rotational forces and cutter geometry and thus is unable to contribute usefully to cooling or lubrication. In addition to the time and cost associated with removal, sharpening and replacement, there is also the disadvantage of time and cost associated with the need carefully to set up and position an external liquid supply pipe.

The present invention seeks, in accordance with one of its aspects, to provide means for reducing the frequency with which a tool needs to be sharpened whilst not incurring the costs associated with use of a tool having an internal fluid passage.

In accordance with one aspect of the present invention there is provided a method for machining material comprising providing an elongate cutting tool at least a part of the length of which has a substantially smooth outer surface of substantially uniform cross-section, providing a chuck for supporting said i cutting tool and providing, at a position to surround said cutting tool, annular orifice means for receiving a supply of pressurised fluid and causing said pressurised fluid to flow from the orifice means in the form of a fluid sleeve in a direction substantially parallel with the major axis of the tool towards the surface region of the workpiece, said method further comprising the step of positioning the cutting tool such that the annular orifice surrounds said part of the length of the cutting tool which has said substantially smooth outer surface.

Accordingly, when using a conventional type twist drill having a helically fluted section and a smooth cylindrical shank section, it is said cylindrical shank i section which is to be axially aligned with the annular orifice.

The method of the present invention may comprise providing a supply of pressurized fluid to the chuck and providing the chuck with said annular orifice means to direct said pressurized fluid to flow from the chuck, externally of the tool, in a direction substantially parallel with the major axis of the tool towards the surface region of the workpiece.

The method may comprise use of a chuck having a hollow body, a collet located at one end of the hollow body for securing a tool relative to the hollow body, a fluid passage for enabling pressurised fluid to flow through the chuck in a lengthwise direction of the collet, from a chamber defined by the hollow body, to said orifice means for directing pressurized fluid to flow from the chuck in a direction substantially parallel with a major axis of the tool towards the surface region of a workpiece.

The fluid flow from the orifice means preferably is in the form of a single annular jet which flows concentric with a major axis of the cutting tool, immediately adjacent the surface of the tool, at at least the position at which the tool extends through the orifice means.

Typically the annular orifice means is stationary when in use and the workplace is caused to rotate, but the invention may be applied also to machining operations in which the tool rotates. In the latter case the orifice means preferably rotates in unison with the tool but may alternatively be stationary.

The invention is particularly suitable when using an elongate tool that is positioned horizontally, but it may also be employed in methods which utilize other tool positions, such as a vertical orientation.

In the case of a chuck comprising a collet it is envisaged that typically the orifice means will be positioned downstream of the collet. Fluid may flow lengthwise of the collet, from a chuck chamber to a downstream positioned orifice means by, for example, a passage defined within the body of the collet, a passage formed between the collet and the chuck body or tool, or by a passage in the wall of the chuck body. The collet may be of the type known as a spring collet and which comprises a plurality of slits, and the said slits may serve as fluid flow passages.

It is not, however, essential that fluid flows lengthwise through a chuck body.

A supply of pressurised fluid may be fed through an external hose or pipe to a position which is substantially axially aligned with said orifice means.

In accordance with another aspect of the present invention there is provided a chuck for selectively retaining a cutting tool, said chuck having a hollow body for through flow of pressurized fluid, and annular orifice means to direct fluid to flow from the chuck in a direction substantially parallel with the major axis of a cutting tool secured in the chuck, at a position immediately adjacent the outer surface of the cutting tool.

The chuck may comprise a hollow body, a collet supported by said hollow body and operable selectively to retain a cutting tool, the collet having two end faces spaced axially as considered in a direction parallel with a major axis of the collet, and fluid flow means for flow of pressurised fluid axially from one end of the collet to the other.

The annular orifice means may be formed integrally with and/or supported by one of the collet and chuck body.

In accordance with yet another aspect of the present invention there is provided an adapter for securing to a machine tool chuck of the kind having a collet retention formation provided with an internal screw thread to locate with an external screw thread at an end of the chuck body whereby said collet retention formation provides an annular shoulder that faces in a direction away from the screw threaded end of the chuck body, said adapter defining an orifice which, in use, directs pressurised fluid to flow in a direction substantially parallel with the major axis of a cutting tool secured in said 3 chuck, said adapter comprising a collar portion having a radially inwardly directed flange in use to abut against said annular shoulder region provided; by the chuck and a face portion securable to said collar portion whereby the adapter is held captive relative to the chuck, said face portion comprising a single centrally positioned aperture through which, in use, the cutting tool extends and through which pressurised fluid may flow.

The adapter may be arranged to receive pressurised fluid via the body of a chuck of a type having a hollow body, and/or it may be provided with an inlet 1 port to receive pressurised fluid via a pipe or hose which is external of the 3 chuck.

The adapter may comprise an inlet port and a selectively removable closure; which, when in situ, inhibits flow through the inlet port whereby the adapter is suitable for use to receive pressurised fluid via the body of the chuck. The removable closure may be a plastics formation and said plastics formation I may be moulded integrally with an adapter portion comprising plastics 3 material. Alternatively an adapter may comprise an inlet port and valve; means selectively operable either to allow fluid flow through the inlet port to the orifice or to inhibit said flow. The valve means optionally may be of a kind operable to vary the rate at which fluid flows therethrough An adapter for receiving pressurised fluid via a passage external of the chuck may comprise a sealing section to inhibit unwanted flow of pressurised fluid into the interior of a hollow chuck via, for example, the slits of a spring collet.

The chuck may comprise a collet retention formation which comprises a collet clamping nut and said adapter may co-operate with said clamping nut to 1 locate the adapter axially relative to the chuck. The radially inwardly directed flange of the adapter collar portion may be adapted in use to bear against a collet clamping nut.

The face portion of an adapter may comprise a single, central aperture of a diameter slightly greater than that of a drill bit, or other tool, of a size accommodated by the collet. It therefore provides, in use, for an annular jet of fluid to flow from the chuck towards a workplace in a direction substantially parallel with the length of the cutting tool. Preferably the aperture has a diameter in the range 105% to 140% of the tool shank diameter, more preferably in the range 1 15% to 130%.

The collar portion and face portion may each comprise substantially cylindrical I surface regions having complimentary screw-thread formations whereby the two portions may readily be secured together or separated for example when access is required to the collet clamping nut to tighten or loosen the grip exerted by the collet on a cutting tool.

The face portion of the adapter may have a generally non-planar, contoured surface for confronting the end of a chuck. Thus it may comprise a first annular and locally planar region which, in use, may be arranged to bear firmly against a planar annular end face of the collet clamping nut and, radially within said first annular region, a second region which is displaced axially from the first region to form a central recess region. Said central recess region may serve two purposes, one being to accommodate any protrusion of the collet beyond the annular end face of the collet clamping nut when the collet is tightened to a minimum working diameter, and the other being to provide a fluid chamber whereby fluid may flow through the radially outer slot regions of a collet and flow via the recess to the or each orifice aperture.

The face portion may comprise an annular region which is radially within said I first annular region and is displaced axially therefrom to provide a retention zone for location of a selected one of a plurality of annular inserts each having I a different size of central aperture. Said central apertures are dimensioned each to be slightly greater than the diameter of the shank of the cutting tool with which that insert is intended to be used such that, in use, the appropriate radially dimensioned annular fluid flow path is created. Said retention zone may be a part of the aforementioned second region or may be additional thereto, for example radially inwards thereof and axially displaced therefrom.

Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying diagrammatic drawings in which: Figure 1 is a longitudinal section of a chuck known per se; I Figure 2 is a side view of a collet chuck assembly (part cut away) also known per se; Figure 3 is a view in the direction of the arrow A of Figure 2; Figure 4 is a view in the direction of the arrow B of Figure 2; Figure 5 is a longitudinal sectional view of a retention collar portion of an adapter in accordance with the present invention; Figure 6 is a longitudinal sectional view of a face portion of an adapter in accordance with the present invention; Figure 7 is a longitudinal sectional view of a combination in accordance with the present invention of a collet chuck and adapter; Figure 8 is a side view of a collet chuck and a drill bit in use to drill a Figure 9 is a section part of a collet assembly comprising another i adapter in accordance with the present invention; Figure 10 is a view similar to that of Figure 9 of another adapter in accordance with the present invention; Figure 11 is a cross-section of part of another adapter in accordance with the invention, and Figures 12 and 13 show variations respectively of the views of Figures 9 end 10.

A collet chuck (10) (see Figure 1) comprises a tubular hollow body (11). One end of the body is provided with an external screw-thread (12) onto which may be screwed a collet retention formation comprised by a collet clamping nut (13) associated with a spring type collet (14) (see Figure 2).

The spring collet (14) is provided with a series of circumferentially spaced slits! (15) each open at one axial end (17) and closed at the other axial end (16) of the collet. The successive slits (15) alternate between being closed at one axial end (23) and open at the other axial end (25) of the collet such that the collet is radially compressible. In consequence the bore defined by the collet i may be reduced to bring the collet into firm engagement with a drill bit (not shown).

The spring collet has a frusto conical outer surface (18) which, in the assembled condition with the hollow body (11), engages with the internal frusto conical surface (19) at that end of the hollow body having the external screw thread (12). Tightening of the clamping nut (13) urges the collet inwards into the body, with the respective frusto conical surfaces in sliding contact such that the slits are forced to reduce in width thereby to bring the collet into said firm engagement with a drill bit.

From Figures 2 & 3 it will be seen that the collet clamping nut (13) comprises an outer annular chamfer (21) and an annular face region (22) which lies in a plane perpendicular to the major axis of the collet. The annular face region defines an aperture which exposes the slotted end face (25) of the collet (14).

Figure 2 & 4 further illustrate the manner in which the alternating arrangement of the successive slits (15) results in a fluid flow path between the axial ends (23,25) of the collet. The axial end (23) of the collet as shown in Figures 2 & 4 defines a central opening of a diameter substantially greater than that of the bore (24) (see Figure 3) defined at the drill bit receiving end (25). Thus the slits provide passages for flow of coolant and lubricating liquid between the ends (23,25).

The chuck (10) as described above with reference to Figures 1 to 4 is of a kind known per se. An example of a suitable chuck of the kind described above is that of the widely known ER pattern and available with a variety of shank types. ! In accordance with the present invention there is provided an adapter (30) comprising a retention collar portion (31) (see Figure 5) and a face portion (32) (see Figure 6).

The retention collar portion (31) comprises a flange portion (33) which defines a central aperture (34) of a diameter just sufficient to pass freely over the external screw thread (12) of the chuck body (10). The collar portion (31) also comprises a sleeve section (35) the radially inner surface of which is provided with a screw thread (36).

The face portion (32) also comprises a sleeve section (37) having an external screw thread (38) which matches the internal screw thread (36) of the collar portion (31). The internal diameter of the sleeve section (37) is just sufficient to pass freely over the radially outer surface of the collet clamping nut (13).

The face portion (32) additionally comprises a first, locally planar, annular region (39) which is dimensioned to bear, in an assembled condition, against the annular face region (22) of the clamping nut. The face portion (32) additionally comprises a central annular region (40) which is offset axially from the first annular region (39) in an axial direction away from screw-threaded region (38). The central region (40) defines an orifice (41) the diameter of which, in this embodiment of the invention, is 125% that of the shank of the tool to be located in the collet (14).

In use of the adapter of Figures 5 & 6, prior to fitting the collet (14) to the hollow body (11), the collar portion (31) of the adapter is slid over the screw- threaded section (12) of the body (11). The collet is then fitted to the hollow body, with the internal screw thread of the collet clamping nut (13) engaging with the external screw thread (12) of the hollow body and the clamping nut is rotated until the collet firmly locates a drill bit in the bore (24). The selected drill bit has an end region shank which is of cylindrical shape and has a smooth, non-fluted surface. The drill bit is arranged with said non-fluted surface aligned with the orifice (41) in the final assembly of the adapter. The adapter face portion (32) is then fitted over the collet clamping nut and the two portions (31,32) are secured together by engagement of the respective screw thread formations (36,38). The axial dimensions of the collar and face portions (31,32) are selected such that on tightening of the screw-threaded formations (36,38) the flange (33) of the collar portion bears against a shoulder (42) defined by the rear face of the collet clamping nut (13) and the first annular region (39) of the face portion (32) bears firmly against annular face region (22) of the clamping nut (see Figure 7) In use of the assembly of the chuck (10) and adapter (13) as shown in Figure 7, said assembly is fitted to a machine spindle or tool station which also supplies pressurised lubricanVcoolant to the bore of the hollow body. The pressurised fluid passes through the collet slits (15) and exits via the annular orifice defined by the space between the drill bit shank and the opening (41) of the central region (40) of the adapter.

As seen by reference to Figure 8, that flow of fluid (82) exiting, as a substantially cylindrical sleeve, through the orifice (41) flows alongside the drill bit (81) to impinge on the workplace (83) in close vicinity to the aperture being formed by the drill bit. The fluid is therefore well positioned to provide a lubricating and cooling effect. In consequence it has been found that in use with a conventional cobalt high speed steel drill a substantially extended drill life is achieved.

In a second embodiment of the invention (see Figure 9) an adapter (90) is constructed substantially as described in respect of the first embodiment, but is suitable for use to receive pressurised fluid either via a pipe or hose external of a chuck or, as described above, to receive said fluid via a collet.

The adapter (90) comprises a retention collar portion (91) corresponding to the aforedescribed collar portion (31) of Figure 5 and a face portion (92). The face portion (92) differs from the face portion (32) of the first embodiment in three respects. Firstly a small annular shoulder (93) is provided between the annular regions (39',40') and serves to locate a plastics sealing disk (94) the purpose of which is described below. Secondly the central annular region (40') lies displaced further from the region (39') than the axial spacing of the regions (39,40) of Figure 6. Thirdly, the face portion (92) of moulded plastics material is formed integrally with a passage (95). The passage (95) has an inner end (96) which is blanked by moulded plastics material, but said blanking material is arranged to be relatively easily removable by drilling or punching.

Without the sealing disk (94), and with the end blank (96) in position, the adapter (90) may be utilised in the same manner as the adapter (30) of the first embodiment of the invention. That is, it may receive a flow of pressurised fluid via slits in a collet (99).

Alternatively, the adapter may be employed to receive a flow of pressurised fluid externally of the collet and supporting chuck (not shown). For that purpose the sealing blank (96) is removed to allow pressurised fluid to be supplied via the passage (95) to an annular chamber (97) defined in part by the central annular region (40'). The sealing disk (94) is formed with a central opening (98) of a diameter corresponding closely with the diameter of the shank (100) of a cutting tool. Thus when pressurised fluid is present in the annular chamber (97), the sealing disk (94) serves to ensure that said fluid flows outward from that chamber substantially only via the annular orifice (101), and is prevented by the sealing disk from flowing in a reverse direction through slits in the collet (99) to the hollow body of a chuck.

Depending on the size of the tool shank (100) the outward end of the collet (99) will either protrude beyond the end face (22') of the collet clamping nut, or lie axially aligned or inwards of that face. In the former situation tightening of the adapter face portion to the retention collar portion after the collet has been tightened to secure the tool shank (100) will result in the sealing disk (94) being held firmly against the end of the collet. In the latter case said tightening of the two portions of the adapter will result in the outer boundary of the sealing disk being held clamped against the outer face (22') of the clamping nut.

Figure 10 shows a variation of the adapter of figure 9. Instead of providing said selectively removable sealing blank (96), the passage 95 of the adapter (110) of figure 10 is provided with a plastics valve (1 11). The valve has an outer slot (112) whereby it may be rotated through 90 degrees so that an internal valve passage (not shown) either allows or prevents flow through the passage (95). In consequence the adapter may be converted readily, by selective use of a sealing disk (94) and rotation of the valve, to be used either only with a supply of pressurised fluid via the chuck or with an additional or alternative supply via the passage (95).

Figure11 shows an adapter having a face portion (112) the radially outer part of which is similar to the corresponding part of the face portion (92) shown in figure 9. However, the annular region (139') is shaped at the radially inner edge thereof to provide an annular seat (140). The seat (140) provides location for a selected one of a plurality of inserts (141) each of which has a central aperture (142) dimensioned to provide an annular orifice immediately about the shank of the drill with which the particular insert is intended to be used. The insert co-operates with the seat (140) to provide a substantially fluid tight seal and thus ensures that in general fluid flowing into the chamber region (143) is directed to flow through the annular orifice between the aperture (142) and the drill shank.

Figure 12 shows a variation of the embodiment of figure 9,. In this embodiment the collar portion (151) has an annular seat (152) for location of a selected one of a plurality of inserts (153) in the manner described above with reference to figure 11. The inserts each have a fluid entry passage (95). The insert (153) and supporting regions (152) of the collar portion provide a seat for a sealing disc (94) as described with reference to figure 9.

Figure 13 shows a variation of the embodiment of figure 10, the variation being similar to that described above in relation to figure 12 but in the context of a collar portion (160) having a side entry valve (161) associated with the insert (162).

Although the invention has been described particularly with respect to the use of an adapter for securing to a chuck, it is to be understood that the method of the invention may be performed by using an orifice means which is independent of the chuck. Thus the orifice means may be defined by an annular device which is provided between the chuck and workpiece, to surround a smooth surface region of the cutting tool and cause fluid to flow in the form of an annular sleeve, in a direction substantially parallel with the length of the cutting tool, towards the workpiece.

JBAKERDE5 t Claims 1. Method for machining material comprising providing an elongate cutting tool at least a part of the length of which has a substantially smooth outer surface of substantially uniform cross-section, providing a chuck for supporting said cutting tool and providing, at a position to surround said cutting tool, annular orifice means for receiving a supply of pressurised fluid and causing said pressurised fluid to flow from the orifice means in the form of a fluid sleeve in a direction substantially parallel with the major axis of the tool towards the surface region of the workpiece, said method further comprising the step of positioning the cutting tool such that the annular orifice surrounds said part of the length of the cutting tool which has said substantially smooth outer surface.

2. Method according to claim 1 and comprising providing a supply of pressurised fluid to the chuck and providing the chuck with said annular orifice means to direct said pressurised fluid to flow from the chuck, externally of the tool, in a direction substantially parallel with the major axis of the tool towards the surface region of the workplace.

3. Method according to claim 1 or claim 2 and comprising use of a chuck having a hollow body, a collet located at one end of the hollow body for securing a tool relative to the hollow body, a fluid passage for enabling pressurised fluid to flow through the chuck in a lengthwise direction of the collet, from a chamber defined by the hollow body, to said orifice means for directing pressurised fluid to flow from the chuck in a direction substantially parallel with a major axis of the tool towards the surface region of a 4. Method according to any one of the preceding claims, wherein an annular jet of pressurized fluid issues from a position immediately adjacent a cylindrical surface of the tool and has an outer diameter in the range 105% to 140% of the diameter of said cylindrical surface.

5. Method according to any one of the preceding claims, wherein use is made of a chuck comprising a collet and the orifice means is positioned downstream of the collet.

6. Method according to claim 5, wherein fluid may flow lengthwise of the collet, from a chuck chamber to a downstream positioned orifice means via at least one of a passage defined by at least one of a slit defined by the body of the collet, a passage formed between the collet and the chuck body or tool, or by a passage in the wall of the chuck body.

7. Method according to any one of the preceding claims, wherein pressurised fluid is fed through an external hose or pipe to a position which is substantially axially aligned with said orifice means.

8. Method according to claim 1 and substantially as hereinbefore described.

9. An adapter for securing to a machine tool chuck of the kind having a collet retention formation provided with an internal screw thread to locate with an external screw thread at an end of the chuck body whereby said collet retention formation provides an annular shoulder that faces in a direction away from the screw threaded end of the chuck body, said adapter defining an orifice which, in use, directs pressurised fluid to flow in a direction substantially parallel with the major axis of a cutting tool secured in said chuck, said adapter comprising a collar portion having a radially inwardly directed flange in use to abut against said annular shoulder region provided by the chuck and a face portion securable to said collar portion whereby the adapter is held captive relative to the chuck, said face portion comprising a single centrallypositioned aperture through which, in use, the cutting tool extends and through which pressurised fluid may flow.

10. An adapter according to claim 9, wherein, in use, it may receive pressurised fluid via the body of a chuck of a type having a hollow body.

11. An adapter according to claim 9 or claim 10 and comprising an inlet port to receive pressurised fluid via a pipe or hose which is external of a chuck.

12. An adapter according to claim 11 and comprising a selectively removable closure which, when in situ, inhibits flow through the inlet port whereby the adapter is suitable for use to receive pressurised fluid via the body of the chuck.

13. An adapter according to claim 11, wherein said removable closure is a plastics formation moulded integrally with an adapter portion comprising plastics material.

14. An adapter according to claim 11 and comprising valve means selectively operable either to allow fluid flow through said inlet port to the orifice or to inhibit said flow.

15. An adapter according to any one of claims 11 to 14 and comprising a sealing section to inhibit unwanted flow of pressurised fluid into the interior of a hollow chuck.

16. An adapter according to any one of claims 9 to 15, wherein said radially inwardly directed flange of the adapter collar portion is adapted in use to bear against a collet clamping nut.

17. An adapter according to any one of claims 9 to 16, wherein said collar portion and said face portion each comprise substantially cylindrical surface regions having complimentary screw-thread formations whereby the two portions may readily be secured together or separated.

18. An adapter according to any one of claims9 to 17, wherein the face portion of the adapter comprises a generally non-planar, contoured surface for confronting the end of a chuck.

19. An adapter according to claim 18, wherein said face portion comprises a first annular and locally planar region which, in use, may be arranged to bear firmly against a planar annular end face of a collet clamping nut.

20. An adapter according to claim 19, and comprising radially within said first annular region, a second region which is displaced axially from the first region to form a central recess region.

21. An adapter according to claim 9 and substantially as hereinbefore described.

22. A machine tool chuck for selectively retaining a cutting tool, said chuck having a hollow body for through flow of pressurised fluid, and annular orifice means to direct fluid flow from the chuck in a direction substantially parallel with the major axis of a cutting tool secured in the chuck, at a position immediately adjacent the outer surface of a cutting tool.

23. A machine tool chuck according to claim 22 and comprising a collet supported by said hollow body and operable selectively to retain a cutting tool, the collet having two end faces spaced axially as considered in a direction parallel with a major axis of the collet, fluid flow means for flow of pressurised fluid axially from one end of the collet to the other, and orifice means to direct fluid to flow from the chuck in a direction substantially parallel with said major axis of the collet, at a position external of a cutting tool secured in said collet.

24. A machine tool chuck according to claim 22 or claim 23 and comprising orifice means formed integrally with and/or supported by the collet.

25. A machine tool chuck according to any one of claims 22 to 24 and comprising orifice means formed integrally with and/or supported by the chuck body.

26. A machine tool chuck according to any one of claims 22 to 25, wherein the orifice means is provided by an adapter according to any one of claims 9 to 21 and secured to the chuck body.

27. A machine tool chuck according to claim 22, wherein the chuck comprises a collet clamping nut and said adapter co-operates with said clamping nut to locate the adapter axially relative to the chuck.

28. A machine tool chuck according to claim 22 and substantially as hereinbefore described.

JBAKERCL3

Claims

Amendments to the claims have been filed as follows zip Claims 1. Method

for machining material comprising providing an elongate cutting tool at least a part of the length of which has a substantiai.y smooth outer sunrace of substa, ,tia"y uniform cross-section, providing a chuck for supporting said cutting tool, said chuck having a hollow body and a collet located at one end of the hollow body for securing a tool relative to the hollow body, providing a collet retention formation operable to cause the coliet to secure said cutting tool to the collet, providing annular orifice means and employing said collet retention formation to support said annular orifice means whereby said orifice means is positioned to surround said cutting tool, supplying pressurised fluid to said annular orifice means and causing said pressurised fluid to flow from the orifice means in the form of an annular fluid sleeve in a direction substantially parallel with the major axis of the tool towards the surface region of a workpiece, said method further comprising the step of positioning the cutting tool such that the annular orifice surrounds said part of the length of the cutting tool which has said substantially smooth outer surface.
2. Method according to claim 1 and comprising providing a supply of pressurized fluid to the chuck and providing the chuck with said annular orifice means to direct said pressurized fluid to flow from the chuck, externally of the tool, in a direction substantially parallel with the major axis of the tool towards the surface region of the workpiece.
3. Method according to claim 1 or claim 2 and comprising use of a chuck having a fluid passage for enabling pressurised fluid to flow through the chuck in a lengthwise direction of the collet, from a chamber defined by the hollow body, to said orifice means for directing pressurised fluid to flow from the chuck, in a direction substantially parallel with a major axis of the tool, towards the surface region of a workpiece.
4. Method according to any one of the preceding claims, wherein an annular jet of pressurised fluid issues from a position immediately adjacent a cylindrical surface of the tool and has an outer diameter in the range 105% to 140% of the diameter of said cylindrical surface.
5. Method according to any one of the preceding claims, wherein use is made of an annular orifice means having an annular region which surrounds the cutting tool and lies displaced axially from the end face of the covet thereby to define an annular fluid chamber adjacent the smooth outer surface of the cutting tool.
6. Method according to any one of the preceding claims, wherein fluid may flow lengthwise of the collet, from a chuck chamber to a downstream À positioned orifice means via at least one of a passage defined by at least one of a slit defined by the body of the collet, a passage formed between the collet and the chuck body or tool, or by a passage in the wall of the chuck body.
7. Method according to any one of the preceding claims, wherein pressurised fluid is fed through an external hose or pipe to a position which is substantially axially aligned with said orifice means.
8. Method according to claim 1 and substantially as hereinbefore described.
9. An adapter for securing to a machine tool chuck of the kind having a collet retention formation provided with an internal screw thread to locate with an external screw thread at an end of the chuck body whereby said covet retention formation provides an annular shoulder that faces in a direction An' away from said screw threaded end to the other end of the chuck body, said adapter defining an orifice which, in use, directs pressurised fluid to flow in a direction substantially parallel with the major axis of a cutting tool secured in said chuck, said adapter comprising a collar portion having a radially inwardly directed flange in use to abut against said annular shoulder region provided by the chuck and a face portion securable to said collar portion whereby the adapter is held captive relative to the chuck, said face portion comprising a sinsle centrally positioned aperture to provide, in use, an annular aperture through which the cutting tool extends and through which pressurised fluid may flow.
10. An adapter according to claim 9, wherein, in use, it may receive pressurised fluid via the body of a chuck of a type having a hollow body.
11. An adapter according to claim 9 or claim 10 and comprising an inlet port to receive pressurised fluid via a pipe or hose which is external of a ch uck.
12. An adapter according to claim 11 and comprising a selectively removable closure which, when in situ, inhibits flow through the inlet port whereby the adapter is suitable for use to receive pressurised fluid via the body of the chuck.
13. An adapter according to claim 11, wherein said removable closure is a plastics formation moulded integrally with an adapter portion comprising plastics material.
14. An adapter according to claim 11 and comprising valve means selectively operable either to allow fluid flow through said inlet port to the orifice or to inhibit said flow.

:e ee.e es:.
15. An adapter according to any one of claims 11 to 14 and comprising a sealing section to inhibit unwanted flow of pressurised fluid into the interior of a hollow chuck.
16. An adapter according to any one of claims 9 to 15, wherein, in use, said radially inwardly directed flange of the adapter collar portion may bear against a collet clamping nut.
17. An adapter according to any one of claims 9 to 16, wherein said collar portion and said face portion each comprise substantially cylindrical surface regions having complimentary screw-thread formations whereby the two portions may readily be secured together or separated.
18. An adapter according to any one of claims 9 to 17, wherein the face portion of the adapter comprises a generally non-planar, contoured surface for confronting the end of a chuck.
19. An adapter according to claim 18, wherein said face portion comprises a first annular and locally planar region which, in use, may be arranged to bear firmly against a planar annular end face of a collet clamping nut.
20. An adapter according to claim 19, and comprising radially within said first annular region, a second region which is displaced axially from the first region to form a central recess region.
21. An adapter according to claim 9 and substantially as hereinbefore described.
22. A machine tool chuck assembly for selectively retaining a cutting tool, said chuck having a hollow body for through flow of pressurised fluid, said chuck comprising a collet supported by said hollow body and operable selectively to retain a cutting tool, the collet having two end faces spaced a. ::. À:. ::e ce.e À .. À .e ace: axially as considered in a direction parallel with a major axis of the collet and said collet providing a plurality of passages for flow of pressurised fluid axially from one end of the collet to the other, and orifice means to receive pressurised fluid from said plurality of passages in the collet and to direct said fluid to flow in the form of an annular fluid sleeve from the chuck in a direction substantially parallel with said major axis of the collet, at a position immediately adjacent the outer surface of a cutting tool secured in said collet, said orifice means being provided by an adapter according to any one of claims 9 to 21 and secured to the chuck body.
23. A machine tool chuck assembly according to claim 22 wherein the orifice defines in part an annular fluid chamber adjacent said other end of the collet.
24. A machine tool chuck assembly according to claim 22 or claim 23, wherein the chuck comprises a collet clamping nut and said adapter cooperates with said clamping nut to locate the adapter axially relative to the chuck.
25. A machine tool chuck assembly according to claim 22 and substantially as hereinbefore described.

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