Device for machining the ends of pipes

#The invention relates to a device for machining the ends of pipes, having a clamping device for clamping the pipe in place, having an outer ring and a shaping insert.

#In piping work, the end faces of the pipe walls are machined before two pipe ends are welded together. The surfaces of the pipe walls which meet at the weld seam have to run precisely at right angles to the axis of the pipeline, must be free of burrs and must be planar. Depending on the type of weld seam, it may be necessary for the end faces to be beveled or rounded. Pipe-flattening and/or chamfering tools are used for this weld preparation work. At a building site, a large number of pipes with different diameters have to be machined as efficiently as possible.

#U.S. Pat. No. 5,941,145 has disclosed a tool for machining pipe ends of the generic type. The clamping device for clamping the pipe end in place substantially comprises a continuous, outer mounting ring, a lower shaping insert in the shape of a half ring and an upper shaping insert in the shape of a half ring. The shaping inserts have an annular inner surface with an internal radius which corresponds to the external radius of the pipe which is to be machined. The outer surface of the upper shaping insert and the inner surface of the mounting ring are designed in such a manner that, in the clamped state, a sickle-shaped space is present between the mounting ring and the upper shaping insert. The shaping inserts are successively introduced into and secured in the mounting ring.

#An exemplary embodiment of the invention is described with reference to the figures, in which:

#FIG. 1 shows a perspective view of a tool for machining the ends of pipes in accordance with the invention,

#FIG. 2 shows a partially sectional view of the tool shown in FIG. 1,

#FIG. 1 shows a perspective view of a portable device or tool 1 for machining the ends of pipes. The tool 1 comprises, as seen from the back toward the front, a drive motor 2, a housing 3, a feed control 4, a working region 5 and a clamping device 6. The tool 1 has an axis X which coincides with the drive axis of the motor 2. In FIG. 1, a drilling tool with a handle 7 and a connection cable 8 is illustrated with the drive motor. In a commercially available drilling tool, the chuck for the drill bit can be unscrewed from the drive shaft and coupled to the housing 3. As an alternative to the drilling tool with the connection cable 8, it is also possible to have an electric motor which is powered by a storage battery, or a hydraulically or pneumatically driven motor, coupled to the housing 2.

#The clamping device 6 comprises an outer ring 9, two clamping screws 10 and 15, which are arranged diametrically opposite one another in the outer ring 9, and a shaping insert 11, which has an internal diameter which precisely matches the external diameter of the pipe which is to be machined. A different shaping insert is supplied for each external diameter. The shaping insert comprises two half-rings 12, 13. The half-rings 12, 13 are produced and supplied in pairs and are formed symmetrically with respect to a center line Z.

#A strap 14 is formed on the housing 3. The strap 14 runs from the housing 3 to the handle 7. The drive axis X of the motor 2, the handle 7 and the strap 14 form a plane A. A base plate 16 with a coupling socket 17 is indicated below the housing 3, parallel to this plane A. The tool 1 can be used with or without base plate as desired, i.e. can be used standing on a support or as a portable and hand-held tool. The protective strap 14 protects the region of the drilling tool in which the main switch is arranged. This ensures that the main switch cannot be switched on unintentionally. This would happen, for example, if the machine 1 were to be removed from the base plate 16 and pressed against a table edge in order to change the clamping device 6 or the tool.