When a metallic pipe is to be joined to another pipe or other component by means of a weld or the like it is generally necessary to condition the internal and/or external surface of the pipe both prior to and after the joining operation is performed. Most importantly, it is necessary to clean the surfaces at the region where the join is to be made in order to remove dirt and oxidation that may have a detrimental effect on the quality of the weld. It may also be necessary to prepare the ends to be joined by removing sharp edges or by fine machining of the ends to facilitate the welding process. After the weld has been formed it is often necessary to remove any weld material that projects from the surface of the pipe by grinding and polishing.

The term"conditioning"is used herein to refer to treatments including grinding, polishing, deburring, rust or scale removal, chamfering, facing and undercutting. Such operations are conventionally performed manually by using abrasive paper or board or, alternatively, by using a hand-held power tool having an elongate circulating abrasive belt or a rotating abrasive disc.

Both the above mentioned techniques require significant effort and are time consuming particularly when both the internal and external surfaces of each pipe require conditioning before and after welding. In certain applications such as the construction, servicing or maintenance of industrial boilers large volumes of pipe have to be conditioned and the task is labour intensive.

Moreover it is often difficult to condition effectively certain pipes in-situ in circumstances where access is restricted.

It is an object of the present invention to obviate or mitigate the aforesaid disadvantages.

According to the present invention there is provided apparatus for conditioning a surface of an object, the apparatus comprising a rotary tool having an axis of rotation, at least one wall and a chamber defined between the axis and the wall for receipt of the object, and a conditioning member for contact with said surface of said object, the conditioning member projecting into said cavity and being fixed to said wall so that it rotates therewith. Preferably each conditioning member is releasably fixed to the wall of the rotary tool. Each conditioning member is preferably received in an axial groove parallel to the axis of rotation.

Each conditioning member may extend in a radial direction from the wall.

The apparatus may preferably comprise a drive shaft for connection to a drive unit.

The wall of the rotary tool may be annular.

Preferably the rotary tool further comprises a bore member located coaxially with respect to the wall of the rotary tool. The bore member preferably comprises at least one conditioning member connected to its outer surface.

The apparatus may preferably comprise a plurality of sections and connection elements for holding the sections together. The connection elements may be the conditioning members.

Each conditioning member preferably comprises at least one abrasive surface.

Biasing means may be provided to bias each conditioning member towards the axis of rotation.

The biasing means may comprise a stream of compressed air or the magnetic attraction of a magnetic material embedded in the main body of the apparatus to the surface to be conditioned.

The aforementioned biasing means may be provided separately or in combination.

The apparatus may preferably comprise a drive unit for driving the tool in rotation.

Specific embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which: Figure I is a perspective side view of a first embodiment of a rotary tool forming part of the apparatus of the present invention, the tool shown without conditioning members ; Figure 2 is an end view of the tool of figure 1 ; Figure 3 is an exploded perspective side view of a second embodiment of the rotary tool of the present invention, shown without conditioning members; Figure 4 is a perspective side view of the rotary tool of figure 3 shown assembled; Figure 5 is a perspective side view of a third embodiment of the tool of the present invention shown with a shaft for connection to a drive unit; Figure 6 is a sectional end view of a fourth embodiment of the tool of the present invention; Figure 7 is a perspective side view of the tool of figure 6; Figure 8 is a sectioned end view of the tool of figure 7 connected to a centrally located bore member, with conditioning members connected to the tool and the bore member; Figure 9 is a perspective side view illustrating the tool of figure 5 when in use, prior to engagement with a pipe to be conditioned; Figure 10 is a perspective side view illustrating the tool of figure 5 when in use, during engagement with a pipe to be conditioned; Figure 11 is a perspective side view illustrating the tool of figure 5 when in use, following engagement of a pipe to be conditioned; Figure 12 is a perspective side view illustrating the tool of figure 4 when in use, during engagement with a pipe to be conditioned; Figures 13 (a) and (b) are an end view and a side plan view respectively of the tool shown in figure 12 connected to a drive unit during engagement with a pipe to be conditioned; Figures 14 (a) to (f) are side views of various embodiments of conditioning members of the present invention; and Figure 15 is an end view of one embodiment of a conditioning member.

Referring now to figures 1 and 2, a first embodiment of the rotary tool 1 comprises an annular member 2 comprising an axially extending wall on the inner surface of which are formed a plurality of equi-angularly spaced, axially extending grooves 3, each groove 3 configured to receive in releasable engagement a conditioning member such as one of those shown in figures 14 and 15. The wall surrounds a space 4 in which a workpiece is to be received. Several tools may be provided each having different longitudinal and radial dimensions of annular member 2 so as to receive objects of differing dimensions.

Figure 3 illustrates a second embodiment of the tool where the annular member comprises four releasably connectable sections 5. Each section 5 is identical and is semi-cylindrical. The sections 5 are arranged in two pairs, the sections of each pair combining to form a complete annular member 6, as shown in figure 4, with six axially extending grooves 7 on the inner surface of each cylinder. The pairs of sections are angularly offset by one groove and are held together by insertion of conditioning members into the grooves 7. Figure 4 shows the tool when assembled, the conditioning members being omitted for clarity. It is to be appreciated that the rotary tool may have different longitudinal and radial dimensions of sections 5 so as to receive objects of differing dimensions.

Figure 5 illustrates a rotary tool having the same construction as figure 1, wherein an annular member 2 comprising an axially extending wall has a plurality of equi-angularly spaced, axially extending grooves 3 formed on its inner surface, but additionally shows a drive shaft 8 for connection to a drive unit. The drive shaft 8 is connected to the axially extending wall by means of a further radially extending wall (not shown).

The embodiment of the rotary tool shown in figures 6 and 7 differs from those described above in that it has a plurality of radial slots 9. Each radial slot 9 is configured to receive any one of the conditioning members shown in figures 14 and 15. Each slot 9 is open to allow a conditioning member to be inserted from the outermost surface of the annular member 10. When in use, the conditioning member in slot 9 engages the end face of the object to be conditioned.

Figure. 8 is an end view of a further embodiment of the apparatus. In this embodiment the tool has a cylindrical bore member 11 coaxially disposed inside the wall of the annular member 12 such that a clearance 13 remains between the wall and the bore member 11 into which a workpiece may be received. Conditioning members 14 are releasably received in grooves 15 of the annular member 12. Each conditioning member has a spine (for example, 16) for location in a groove (for example, 15) and a radially projecting abrasive member (for example, 17). The conditioning members 14 are used to condition the outer circumferential surface of a pipe as described below. Further conditioning members 18 are connected into grooves 19 in the outer surface of the bore member 11. The grooves 19 are disposed so that conditioning members 18 project in to the space between conditioning members 14. The conditioning members 18 are used to condition the inner circumferential surface of a pipe. It is to be understood that embodiments of the apparatus would be provided comprising different longitudinal and radial dimensions of central bore member 11 configured to engage objects of differing dimensions.

Conditioning members 20 are connected to the inner surface of the annular housing 12 utilising the radial slots 9 shown in figures 6 and 7 (not shown in figure 8) and are used to condition the end face of a pipe.

Figures 9,10 and 11 illustrate an embodiment of the apparatus, such as that shown in figure 5, in use. The rotary tool 1 is connected to a drive unit 21 utilising the drive shaft 8. Figure 9 illustrates the apparatus prior to engagement of a pipe 22 to be conditioned. The pipe is then inserted into the space 4 and the conditioning members flex to accommodate its insertion (figure 10). The rotary tool is driven in rotation by the drive unit 21 in the direction of arrow A during engagement of the pipe 22. As the tool rotates the conditioning members (not shown) pass over the outside surface of the pipe 22 thereby conditioning the surface. If the embodiment of figure 8 is used, wherein the tool comprises a cylindrical bore member 11 coaxially disposed inside the wall of the annular member 12, then the conditioning members 18 additionally pass over the inside surface of the pipe thereby conditioning it simultaneously with the outside surface. Figure 11 illustrates the apparatus following engagement of the. pipe 22. The darkened end 23 of the pipe 22 in figure 11 represents the conditioned exterior surface.

Figures 12,13 (a) and 13 (b) show the embodiment of the apparatus of figure 4, in use. The tool is assembled from the plurality of sections 5 around a pipe 24 to be conditioned. The outside surface of the annular member 6 is frictionally engaged with a rotary drive wheel 25 of a rotary drive unit 26 during engagement of the pipe 24. Mounted on either side of the wheel 25 is a support member 27 that abuts the pipe 24 during engagement of the rotary tool by the rotary drive wheel 25. The support members 27 each have a recess 28 that receives the pipe surface.

Figure 14 illustrates various embodiments of each conditioning member 14,18 or 20, which may be used with the apparatus. Each conditioning member 14,18 or 20 comprises two sections: a substantially rigid spine 29 of cylindrical section that is complementary to the shape of a groove (for example, groove 3 of figure 1) and a substantially flexible abrasive member 30 received in the spine 29 and projecting radially therefrom. A plurality of abrasive members may be used with each spine 29. so that as a leading abrasive member wears a fresh member is revealed behind it. The abrasive member of each conditioning member may be substantially rectangular in side view (figures 14 (a), 14 (c), 14 (e) and 14 (f)) possessing a leading edge 31 parallel to the spine 29 or may comprise a leading edge 32/33 that is at an angle to the spine 29 (figures 14 (b) and 14 (d)). Abrasive members 30 constructed of different materials may be provided, for example, figure 14 (a) illustrates an abrasive member 30 with a fine abrasive surface, figure 14 (c) illustrates an abrasive member 30 with a combination of more fine and more coarse abrasive surfaces, figure 14 (e) illustrates an abrasive member 30 with a coarse abrasive surface and figure 14 (f) illustrates an abrasive member 30 with an alternative arrangement of more fine and more coarse abrasive surfaces to that in figure 14 (c). This range of different embodiments allows a user to select the conditioning member 30 with the most suitable combination of size, shape, flexibility and abrasive characteristics for the job to be performed.

Although the spine 29 is of circular cross-section in these embodiments, it may be otherwise shaped.

The apparatus of the present invention is versatile in that it may be used to condition different surfaces of a pipe independently or simultaneously. For example, if all three sets of conditioning members 14,18 and 20 are utilised as shown in figure 8, the inner and outer circumferential surfaces, and end face of a pipe may be simultaneously conditioned using the procedure shown in figures 9 to 11. Alternatively, utilising the embodiment shown in figures 3 and 4, the outer circumferential surface of a pipe may be conditioned substantially throughout its length. The versatility of the invention is further extended by the availability of different embodiments of both the annular member 2,6 or 10 and the bore member 11 allowing the user to select the particular embodiment which best suits the job to be performed. The range of conditioning members (figures 14 and 15) provided permits additional user customisation of the apparatus.

In an embodiment not shown in the drawings, means may be provided to bias each conditioning member towards the axis of rotation of the rotary tool thereby forcing each conditioning member against the surface to be conditioned. In a one embodiment, the biasing means may comprise a stream of compressed air. In another embodiment, the biasing means may be provided by magnetic attraction. The magnetic attraction would act between a magnetic material embedded in the annular member of the apparatus and the surface to be conditioned. The two aforementioned biasing means may be provided separately or in combination. The use of compressed air may find general application with surfaces manufactured from many different materials, such as stainless steel. The use of magnetic attraction would not be as widely applicable, it being restricted to pipes manufactured from magnetic materials, such as carbon steel.

In the embodiments illustrated and described, the apparatus is used to condition a pipe.

However, it is to be appreciated that the apparatus may be used to treat the surfaces of other objects and that the tool need not be annular in shape.