EP0386303B1 - Stepped brush - Google Patents

Description

The invention relates to a brush, in particular for processing pipeline pipes, according to the preamble of claim 1.

When machining workpieces, in particular pipeline pipes, there is often the need to carry out the desired work process using several different brushes. The result of this is that various individual operations are required, for example in order to process the pipeline pipe in the desired manner. This is based on the fact that, before they come to the construction site, such pipes are coated in the outer area with a plastic layer, in particular made of polyethylene, which serves as a surface protective layer against corrosion in use. This plastic layer must be removed in a suitable manner before joining two pipes together. In addition, it should be ensured that the abutting end regions of two pipeline pipes are processed correctly and are freed of unwanted foreign bodies. The operations required for this have previously been carried out manually using several different, for example braided, brushes.

A brush for cleaning internal and external threads of pipes is known from US Pat. No. 2,661,494, which consists of individual brush segments. These are arranged in such a way that there is a straight, slightly conical outer peripheral surface between the two ends of the brush. With this known brush, however, it is not possible to process pipes, in particular plastic-coated pipeline pipes, in such a way that a precisely defined profile is produced in the region of the pipe ends.

The invention is therefore based on the object of creating a brush according to the preamble of patent claim 1, with which a workpiece, in particular a pipeline pipe, can be machined both on the peripheral surfaces and on the end surfaces in a single operation.

The features of the invention created to achieve this object result from claim 1. Advantageous refinements thereof are described in the further claims.

The brush designed according to the invention consists of three brush segments, the outer brush segment having the largest outer diameter and the middle brush segment being provided with a cylindrical outer circumference and the outer brush segment having a chamfer at the transition point to the middle brush segment. The brush segment with the smallest outer diameter has an outer diameter that tapers conically with increasing distance from the middle brush segment.

The outer diameter of the brush segments can thus be adapted to the finishing profile of a pipeline steel pipe covered with a plastic layer. This makes it possible to completely process the pipeline pipe in a single operation with the step brush according to the invention. At the same time, the outer wall of the pipeline pipe encased in the plastic layer and the butt sides of the pipe can be machined exactly at the required angle.

It is easily possible to manufacture the brush segments from different materials or to have different brush parts.

The two outer brush segments can each consist of a plastic-bonded wire brush part, while the middle brush segment is formed from several braided individual rings.

The brush segments are expediently held on the inner core in such a way that they are held between a holding disk or the like fastened to the front end of the inner core and a securing ring which is detachably fixed to the inner core at a distance therefrom. This makes it possible not only to replace individual brush segments that are worn out prematurely or earlier than the other brush segments due to a particularly intensive work process, but also to lengthen or shorten the entire brush depending on the given work requirements. The brush can thus be used for all types of pipes. Since the brush packs wear differently and, as explained, there is the advantageous possibility of replacing the worn brush segments prematurely, the life of the entire brush is also significantly extended.

Finally, it is within the scope of the invention that the inner core carrying the individual brush segments is designed as a receiving tube which has a plurality of radial bores in its wall for the exit of cooling air. By means of this cooling air, which is allowed to emerge from the inner core from the inside to the outside, for example in the form of compressed air, it is possible to cool the work surfaces of the individual brush segments in the desired manner, so that the brush cannot overheat. So that the duration of use the brush can be extended significantly.

The invention is explained below with reference to the single figure of the drawing. This shows schematically in side view or partially in section the brush according to the invention when processing a pipeline steel pipe.

As can be seen from the drawing, the brush 1 shown, which in the exemplary embodiment provided is designed as a three-stage brush, is used for processing in a pipeline steel pipe 2. This is coated in its outer area with a polyethylene-plastic protective layer 3, which extends to the respective pipe end 4. Before such a pipeline pipe 2 can now be connected to another pipeline pipe 2 on the face side, it is necessary to process the respective pipe end ends 4 in a suitable manner and also to remove the plastic protective layer 3 in a certain area near the pipe end end 4.

This is done by means of the brush 1, which has an inner core 5 and a rotationally symmetrical outer brush part mounted thereon. In the exemplary embodiment shown, this outer brush part is formed from three brush segments 6, 7, 8, which are designed in the form of an annular disk and are successively fitted onto the inner core 5 and are held there interchangeably.

As can be seen from the drawing, the three brush segments 6, 7, 8 have different outer diameters, so that this results in the three-stage brush 1 described. In the special exemplary embodiment, the middle brush segment 7 has a largely cylindrical circumference and consists of several knitted individual rings, which are not shown in detail in detail. In contrast, the two outer brush segments 6, 7 each consist of a plastic-bonded wire brush part.

If desired, braided single rings can also be provided.

The three brush segments 6, 7, 8 overall have such a profile of their outer diameter that it is adapted to the finishing profile of the pipeline steel pipe 2 covered with the plastic layer 3. For this purpose, the outer brush segment 8, which has the largest outer diameter, is provided with a cylindrical outer periphery, similar to the middle brush segment 7, but in such a way that the transition to the outer periphery of the middle brush segment 7, which has a smaller outer diameter, takes place in steps. At this transition point, an inclined chamfer 9 is provided, the inclination of which is designed such that it corresponds to the desired end inclination of the end face 4 of the pipeline pipe 2.

In contrast, the leftmost outer brush segment 6 in the drawing has a conically tapering outer diameter, so that this also ensures that the transition point between the plastic layer 3 and the exposed outer wall of the pipeline pipe 2 runs at the desired angle.

The three brush segments 6, 7, 8 are held on the inner core 5 in that they are held between a retaining disk 11 or the like fastened to the front end 10 of the inner core 5 and a securing ring 12 which is detachably fixed to the inner core 5 at a distance therefrom. This locking ring 12 engages in the usual manner in each case in a circumferential groove 13 of the inner core 5. As can be seen, a plurality of circumferential grooves 13 are provided on the inner core 5 at a distance from one another, so that the retaining ring 12 can be fixed at different distances from the retaining disk 11. As a result, the total length of the brush 1 can also be increased or decreased as desired. This means that the brush 1 for example in its cylindrical area, ie in the area of the middle brush segment 7, depending on the type of pipeline pipe 2 to be processed, it can be lengthened or shortened. The brush 1 can thus be used variably for all types of pipes.

As can also be seen from the drawing, the inner core 5 is designed as a receiving tube. This has in its wall for the exit of cooling air a plurality of radial bores 14 which are arranged both at an axial distance and at a circumferential distance from one another. The compressed air used for this purpose, for example, emerges from the inside of the inner core 5 through the radial bores 14 and strikes the working surfaces of the brush 1, in particular the working surface of the middle brush segment 7. This effectively prevents the brush 1 from overheating, which considerably extends the overall service life of the brush 1.

With regard to features of the invention not described in detail above, reference is expressly made to the drawing and to the claims.

Claims (6)

1. A brush, more particularly for processing of pipeline tubes, comprising an outer, axially symmetrical part co-rotatably secured to an inner core or holder and comprising a number of annular segments, which are successively drawn over the inner core and interchangeably held there and have differing diameters, characterised in that the brush comprises three segments (6, 7, 8), the middle brush segment (7) and the outer segment (8), which has the largest outer diameter, having a cylindrical outer periphery, and the outer brush segment (8) having a chamfer (9) at the transition to the middle segment (7), whereas the segment (6) with the smallest outer diameter has an outer diameter which tapers conically with increasing distance from the middle brush segment (7).
2. A brush according to claim 1, characterised in that the brush segments (6, 7, 8) are made of different materials and/or consist of different brush parts.
3. A brush according to claim 1 or 2, characterised in that the two outer brush segments (6, 8) each comprise a plastics-bonded wire brush part.
4. A brush according to any of the preceding claims, characterised in that the middle brush segment (7) comprises a number of plaited individual rings.
5. A brush according to any of the preceding claims, characterised in that the brush segments (6, 7, 8) are held between a retaining disc (11) secured to the end face (10) of the inner core (5), and a securing ring (12) releasably attached to the inner core (5) at a distance from the retaining disc.
6. A brush according to claim 5, characterised in that the inner core (5) is in the form of a receiving tube and its wall has a number of radial bores (14) for escape of cooling air.

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