GB2262900A - Machine tool support - Google Patents

Abstract

The device comprises a pair of end frames (81) inter-connected by axial extending bars (79) and a machine tool (70) can be mounted by means of a mast (73) and the end plates rotated around a part (71) of a workpiece such as a roller (72). A tool (86 or 88) carried by one of the end plates (81) can carry out a machining operation on the part (71) or on a shoulder (89). The end plates can be stationary and located relative to the workpiece, a carriage (13, see Fig. 1, not shown) being mounted to travel along the bars (79) and carry a tool to carry out an engineering operation such as turning, milling or welding, and also for thread cutting, taper turning and radiussing if desired. <IMAGE>

Description

Machine Tool This invention relates to a machine tool.

It is an object of the present invention to provide an improved machine tool which can be used for the treatment of components by carrying out machining, grinding, welding and comparable operations.

The invention provides a portable machine tool adapted to be connected to a workpiece, the tool including a pair of locators, each adapted to mount the machine tool relative to the workpiece and to adjust an axis of the machine tool relative to the workpiece, a plurality of rails extending between the locators and mounting a carriage translatable along the rails by a drive; a tool post carried by the carriage and adapted to mount a treatment tool for operating on the workpiece during travel of the carriage.

The operation carried out on the workpiece will usually be a machining operation, but if desired the action can be a grinding, welding or other operation action depending upon the nature of the treatment tool carried in the tool post. The tool post is preferably constructed and arranged to that the position of action of the tool can be varied, as desired, in a direction transverse to the axis of the work piece.

Each locator can be of multi-port construction to allow it to be arranged around a workpiece. Parts of the locator can be separate and connectable by fasteners, or can be pivotably connected and securable in an engaged condition by fasteners.

End assemblies including locators can be similarly constructed.

Each locator can be part of an end assembly which includes a rotor, the two rotors mounting the rails and forming, with the rails, a rotatable cage carrying the carriage.

Means for rotatably driving the cage can include a ring gear on one rotor engaged by a pinion on the respective locator.

Each locator can have means for extending inwardly or outwardly to mount the machine tool within or around the workpiece.

The carriage can be a part-annular body, or can be a complete annulus movable along the rails.

The tool post can be arranged to be operative internally and/or externally so as to perform be capable of mounting a tool or tool assembly for performing an operation on a workpiece within or outside the cage.

The cage can be annular and disposed around a work piece to be machined such as a shaft or comparable structure. In the case of a shaft mounted on bearings the annular cage can be arranged to be mounted upon portions of the shaft outside a bearing portion and to machine both the shaft within the bearing and the surface of an external bearing mounting. The so-created enlarged space then accommodating an oversized bearing bush or comparable structure.

The carriage can include a tool magazine including a plurality of tools which can be selectively moved to a operating position.

The carriage can include tool magazine including an external or internal cam ring operating to bring selected one of the tools into an operating position.

When the end assemblies are in two (or more) parts which are movable into and out of an embracing relationship relative to a shaft, bearings between the rotors and the locators can be arranged to withstand both radial and axial movement. The connecting of each locator and its rotor into position around the shaft (or within a hollow workpiece) can serve to engage the bearing (parts on the locator and rotor) and ensure a tolerance and slack-free relationship between the two parts of the bearing.

The cage can be driven by having a gear ring which is engaged by a pinion which is in turn driven by a prime mover such as a motor which may be electrical, hydraulic or pneumatic.

The carriage can be translated along the rails by means of a lead screw or a comparable mechanism and may or may not be synchronised to the rate of rotation of the cage. The drive to the carriage can be independent of rotation of the cage or can be synchronised thereto by an epicyclic gear mechanism or a comparable arrangement.

The invention will now be described further, by way of example, with reference to the accompanying drawings wherein; Figure 1 is a schematic view illustrating a simple portable machine tool in accordance with the invention; Figure 2 is a comparable view but illustrating a different machine; Figure 3 illustrates a machine of the invention arranged to machine a central portion of a shaft; Figure 4 shows a girdle of the machine of figure 3; Figure 5 is an end view of the girdle shown in figure 3; Figure 6 is an end view of part of the machine tool; Figure 7 is a side elevation of a further embodiment of machine tool of the invention; Figure 8 is an enlarged view, partially in cross section of part of the machine of figure 7; QanaW Figure 9 is a side elevation, partially in cross section, showing a further machine in accordance with the invention.

Referring now to figure 1, it will be seen that a first preferred embodiment of the portable machine tool (10) of the invention has a pair of end locators (11) which support rails (12) along which a carriage (13) carrying a tool post (14) can be driven by a lead screw (not shown) or a comparable mechanism.

The machine tool (10) can be adapted to be secured to either external workpiece and/or an internal workpiece such as a shaft (16). When being secured within a workpiece (15) the locators (11) are provided with means indicated at (17) for exerting a force outwardly of the locators (11) to position the locators Figure 10 is a partial side elevation illustrating a further modified machine; Figure 11 is a similar view of a further possible modification; Figure 12 is an end view of the part shown in Figure 10; and Figure 13 is an end view of the part shown in Figure 11.

relative to the workpiece (15). Such means (17) is desirably constructed so that the position of the axis of the machine tool (10) then can be varied relative to the workpiece (15).

If the machine tool (10) is solely for operating within a workpiece the locators (11) can be in the form of discs, by rectangular or by of other shapes. If, however, the machine tool is intended for use in relation to an internal workpiece (16) the locators (11) can be in the form of rings such as annually and the carriage (13) can be in the form of a girdle having a through aperture. For use in relation to an internal workpiece (16) the locators (11) are provided with means indicated at (18) for gripping the workpiece (16) and positioning the axis of the machine tool relative to the workpiece (16).

In the machine tool of figure 1 the carriage (13) can be moved along the rails (12) and carry out a machining operation longitudinally of either workpiece. The tool post (14) can be movable on the carriage (13) so as to allow the creation of various different surfaces on the workpiece (15) or (16). Of course, instead of the tool post (14) mounting convential machining tools the tool post can carry grinding, polishing, welding or comparable treatment means.

If the machine tool (10) is to be used in relation to an internal workpiece (16) and for any reason the machine tool can not be slid over the end of the workpiece (perhaps due to the existence of outwardly extending flanges or other structures which cannot be detached from the workpiece), it is desirable if the machine tool is constructed so that the locators (11) can be separated to allow the machine tool (10) to be engaged around the workpiece and then re-connected, the locators can be in several parts, securable by fasteners, or can be pivoted together so as to open in the manner of a pair of jaws and then be locked around a workpiece (16).

Figure 2 shows a second machine of the invention which is similar to the machine figure 1 except that each locator (11) is part of an end assembly (19) which includes the locator (11) and a rotor (20). The rotors (20) and rails (12) form together a rotatable cage which bears the carriage (13). The cage can be rotated by means of a ring gear (21) driven by pinion (22) in turn driven by a motor (23).

It will be appreciated that the cage composed of the two rotors (20) and the rails (12) can turns and bear with it the carriage (13). Tools carried by the tool post (14) can then carry out rotary machining operations either in external turning of a workpiece such as the shaft (16) or the facing of shoulders thereon and comparable operations on the internal surface of the workpiece (15).

Again, if the machine is only to be used internally it will not be necessary for the end assemblies (19) to multi-part. However, usually the machine tool will be designed to enclose a workpiece therefore the end assemblies will usually be multi-part, being either in separable parts, fastenable together in position or in two or more parts pivotally connected together and provided with appropriate locking means.

Figures 3 and 4 show, in more detail, a machine tool (24) which is specifically adapted to be clamped around a shaft (25) and used to machine a central portion (26) thereof. It will be seen that due to the formations (27) (28) the machine tool (24) can not be slid over the end of the shaft (25) but needs to be of multi-part construction so that it can be disposed to surround the shaft (25) and be connected thereto. This particular aspect of the machine tool (24) will be described in relation to later figures.

Machine tool (24) has a pair of end assemblies (29) each of which has a locator (30) and a rotor (31). The two rotors (31) carry rails (32) and together therewith form a cage which supports the annular carriage or girdle (33) which supports the tool post (34).

Each locator (30) is generally annular in shape and centrally has a through aperture (35) whose size is slightly greater than the diameter of the shaft (25). Within the aperture (35) is arranged a tapered surface (36) and a collet arrangement (37) can be urged against the surface (36) to secure the locator (30) to the shaft.

Such a locating arrangement is ideal when the portion (26) must be turned so as to be concentric with the other portions of the shaft (25). However, if it should be for any reason that the axis of the machine tool (24) needs to be spaced from or at a different angle of the supporting portions of the workpiece, an alternative form of mounting, for example a plurality of generally radial extending clamping fingers, can be used allowing the disposition of the axis to be varied within a small range.

Each locator (30) mounts its rotor (31) by means of a tapered bearing ring (38) lubricated via (39). It will be appreciated that the engaged generally V-shaped bearing surfaces between the rotor (31) and the bearing ring (38) make for a secure and play-free mounting for the cage both radially and axially. It will also be appreciated that use of such an angled bearing arrangement is only possible when the end assembly (29) is in two parts which can be assembled in a generally radial direction.

It is also useful if the degree of clamping between the various parts (usually two) of each of the locator and the rotor is such that the bearings can be compressed to a limited extent to as to eliminate play.

In the left hand assembly (29) it will be seen that the rotor (31) carries a ring gear (39) which is engaged by a pinion (40) driven by a motor (41) which may be hydraulic, pneumatic or electric.

The machine tool (24) operates in the same way as the tool illustrated in figure 2. A tool carried on the tool post at a position generally indicated at (42) can be used to machine a the area (26) or by appropriate adjustment the shoulder surfaces indicated at (43) and (44). The tool post (33) also has a further tool receiving position at (45). The carriage is driven by the lead screw (45), being mounted on the rails (32) by means of bushes (46).

Figure 5 shows, in some more detail, how the girdle (33) is provided with a tool post (47) which has a slot (48) which cooperates with a stop (49). The position of the tool post is determined by rotation of the tool post lead screw (50) turned manually by means of sleeve (51).

Figure 6 shows how a locator (30) can be disposed around a workpiece. In figure 6 it will be seen that the locator (30) has two parts (52) (53) pivotally connected at (54) and securable by means of a bolt (55). Although not shown, each rotor (31) is similarly constructed.

Also shown in figure 6 is a gear arrangement (56) whereby the lead screw (57) can be driven at will depending upon the position of the drive knob (58).

Figure 7 illustrates a further machine tool (59) of the invention, which is used in a special situation wherein a shaft such as a ships propeller shaft (60) passes through a mounting (61) for a bush, the mounting (61) being itself part of an intermediate supporting the shaft (60). The machine tool (59) has end assemblies (60, 61, 62, 63) which are similar to the assemblies (29).

However, because of the small annular gap being the shaft (60) and the mounting (61), the machine tool (59) has a carriage in the form of a thin annular girdle (64). The girdle (64) carries a tool post which can have a tool which operates either on the shaft or on the mounting (61). Thus, once mounted on the shaft the machine tool can machine the portion thereof which passes through the bracket and can also re-machine the interior surface of the bush mounting (61). After the machining operations an over sized bush or bearing assembly can be replaced into the annular space between the shaft (60) and the mounting (61).

Figure 8 shows, in detail, how motion is transmitted to a rotor (65) of the machine tool (59). Rotor (65) carries an inner ring gear (66) which is engaged by a pinion (67) which in turn is driven from a motor (68) by means of bevel gears (69).

Figure 9 illustrates a further embodiment of machine tool (70) of the invention which is suitable for use in machining a bearing portion (71) of a roll (or like item) (72). In this embodiment the machine tool is not mounted directly on the work piece (part 71 ) or on the roll (72). Instead, a fixed mast (73) is provided which is co-axial with the work piece (71). The mast (73) can be a separate item secured to the work piece (71) as by screws, welding or the like and later removed. Alternatively the mast (73) can be formed on the end of the work piece as a permanent structure if this is practical and/or desirable.

A cylindrical body (74) is mounted for rotation about the mast (73) by means of bearings (75). The body has circumferentially spaced bushed apertures (75, 76) formed in respective annular end flanges (77, 78). The respective bores (75, 76) slidably support bars (79) which together with upper and lower edge members (80, 81) form a rotable cage. End members (80 and 81) are annular, member (81) to surround the work piece and member (82) to provide entry for a motor (82) which has a pinion (83) which engages an internal ring gear (84) on the body (74).

The cage (79) can be moved axially by means of a lead screw (84) which is shown detached from its normal position where its axis lies on line (85). This can cause the cage to perform movement along the axis of the work piece.

End member (81) is in the form of an annulus which includes one or more tool posts. To the right of figure 9 a portion of the member (81) is shown as mounting a tool (86) by means of a tool post whose construction is not illustrated. The tool (86) can be moved axially whilst the cage rotates about the axis thus machining the cylindrical surface of the portion (71). To the left a portion (87) of the annulus (81) can form a tool post and carry a tool indicated at (88) for facing the shoulder (89) between the portions (71) and the body of the roll (72). In each case the tool post can be manually adjustable so as to vary the position of the tool relative to the work piece.

It will be appreciated, of course, that instead of the rotatable body being mounted on a separate mass connected to the end of the work piece portion to be machined, an annular body could be mounted on the roller (72) itself for rotation with the posts carried by annulus (81) effective to perform operations on the portion (71).

The invention is not limited to the precise details of the foregoing and variations can be made thereto.

For example, instead of the end assemblies being in two parts they can be in three or more parts if desired and for ease of handling when large shafts have to be encircled. There can be two or more pivotal connections if necessary. The carriage can be either in the form of a complete annular girdle or can be of a part-annular construction or the like.

Instead of carrying out a purely machining operation the carriage can mount a grinding wheel or the like adapted to carry out a grinding operation, power being taken from an epicyclic gear arrangement, lead screw, or electrically if the cage is provided with slip rings and an appropriate electrical supply. In a similar manner a welding head could be incorporated and any other convenient operation performing mechanism mounted on the carriage so as to carry out operations on either an internal or external workpiece during generally axially motion or combined axially and rotational motions.

The girdle can include a magazine mounting a plurality of tools selectively movable to an operative position. The magazine can include a cam ring (desirably external), rotation of which effects movement of the tools between their retracted and operative conditions.

The machines can be driven by electric pneumatic or hydraulic motors.

Many other variations are possible within the scope of the invention.

Figures 10 and 12 illustrate a first possible further modification whereby the machine tool can be adapted to carry out a third cutting operation. This machine can be comparable to the machine shown in Figure 9 except that end frames 111 carry, as well as spacers/travel bars 112A, lead screw 113 which can be driven via gearing such as a gear train or a toothed belt or chain from a rotational drive of the machine 110. A carriage 114 is slideably mounted on two of the bars 112 and has a nut 115 engaged with the lead screw 113. The carriage 112 carries the tool holder 116 wherein is mounted a tool 117 whose projection can be varied using knob 118.

In use, for example when mounted in a manner similar to the machine tool shown in Figure 9, the machine 110 can be mounted so that its end frames 111 rotate about the stationary workpiece whilst the lead screw drives the carriage 114 along the bars 112 thus causing the tool 117 to perform a thread cutting operation on the workpiece. A thread can be formed in a series of passes adjusting the depth of the tool after each pass.

The machine tool shown in Figures 11 and 13 is similar in many respects to the machine tool 110 in that carriage 114, slideable on bars 112 as is engaged by lead screw 113. In this machine tool, however, the tool holder 116 and tool 117 are replaced by a head 121 which mounts a milling cutting 122 which can be rotated by means of a electric or hydraulic motor driven by a connected flexible supply line 16 Using the machine tool 120 the end plates 111 would not, normally, be rotated about the workpiece in view of the need to have flexible connection to the motor 123. However reciprocating circular motion would be possible. Usually, however, the milling cutter 122 will be used to cut keyways and the like in a workpiece and this can be affected by maintaining the end frames 11 stationary and driving the cutter peraxially using the lead screw 113.

It will be appreciated that although the machine tools 110 and 120 have been shown as acting on a workpiece which is disposed internally thereof, similar considerations apply to hollow tubular workpieces wherein the machine tool 110 or 120 could be disposed inside the machine and the tool 117 or cutter 122 could be disposed to project radially outwards to perform a similar or comparable operation on an interior surface of a workpiece.

In each case, of course, instead of third cutting and milling appropriate tools can be provided to carry out a variety of other common engineering processes. In particular, taper turning could be effected provided the direction of travel of a cutting tool or milling cutter is appropriately controlled, for example by a power feed to the downfeed nob shaft. In a similar manner radiusing can also be carried out at a junction of two different diameters of workpiece section.

Claims (24)

CLAZS

1. A portable machine tool adapted to be connected to a workpiece; the tool including a pair of locators, each adapted to mount the machine tool relative to the workpiece and to adjust an axis of the machine tool relative to the workpiece, a plurality of rails extending between the locators and mounting a carriage translatable along the rails by a drive; a tool post carried by the carriage and adapted to mount a treatment tool for operating on the workpiece during travel of the carriage.

2. A tool as claimed in claim 1, wherein the operation carried out on the workpiece is selected from machining, grinding, welding, screw-catting, taper-turning, face turning and radiussing.

3, A tool as claimed in claim 1 or 2 wherein the tool post is constructed and arranged so that the position of action of the tool can be vried, as desired, in a direction transverse to the axis of the work piece.

4. A tool as claimed in claims 1, 2 and 3, in which each locator is of multi-part construction to allow it to be arranged around a workpiece.

5. A tool as claimed in claim 4, wherein parts of the locator are separate and connectable by fasteners.

6. A tool as claimed in claim 4, wherein parts of the locator are pivotably connected and securable in an engaged condition by fasteners.

7. A tool as claimed in claim 4, wherein end assemblies including locators are similarly constructed.

8. A tool as claimed in any preceding claim wherein each loctaor is part of an end assembly which includes a rotor, the two rotors mounting the rails and forming, with the rails, a rotatable cage carrying the carriage.

9. A tool as claimed in claim 8 wherein means for rotatably driving the cage includes a ring gear on one rotor engaged by a pinion on the respective locator.

10. A tool as claimed in claim 8 or 9 wherein each locator has means for extending inwardly or outwardly to mount the machine tool within or around the workpiece.

11. A tool as claimed in any preceding claim wherein the carried is a part-annular body.

12. A tool as claimed in any of claims 1 to 10 wherein the carriage is a complete annulus movable along the rails.

13. A tool as claimed in claim 8 or any claim appendant thereto wherein the tool post is arranged to be operative internally and/or externally so as to be capable of mounting a tool or tool assembly for performing an operation on a workpiece within or outside the cage.

14. A tool as claimed in claim 8 wherein the cage is annular and disposed around a workpiece to be machined such as a shaft.

15. A tool as claimed in claim 14 in combination with a shaft mounted on bearings, the annular cage being arranged to be mounted upon portions of the shaft outside a bearing portion and to machine both the shaft within the bearing and the surface of an external bearing mounting.

16. A tool as claimed in any preceding claim, wherein the carriage includes a tool magazine including a plurality of tools which can be selectively moved to an operating position.

17. A tool as claimed in any preceding claim, wherein the carriage includes a tool magazine including an external or internal cam ring operating to bring selected one of the tools into an operating position.

18. A tool as claimed in claim 7, wherein the end assemblies are in two (or more) parts which are movable into and out of an embracing relationship relative to a shaft, and bearings between the rotors and the loctors are arranged to withstand both radial and axial movement.

19. A tool as claimed in claim @ wherein the cage is driven by having a gear ring which is engaged, by a pinion which is in turn driven by a prime mover such as a motor which may be electrical# hydraulic or pneumatic.

20. A tool as claimed in any preceding claim, wherein the carriage can be translated along the rails by means of a lead screw or a comparable #echanism.

21, A tool as claimed in claim 20 wherein the drive to the carriage is independent of rotation of the cage

22. A tool as claimed in claim 20 wherein the drive can be synchronised to cage movement.

23. A tool as claimed in claim 22, wherein synchronism is by an epicyclic gear train.

24. A machine tool substantially as described with reference to the accompanying drawings.