This invention relates to a tool for forming a chamfer in the outer surface at the end of a pipe (especially a plastics pipe), pa ticularly for facilitating the coupling together of two pipes or of one pipe and an end fitting or the like.

Tools have been proposed previously for forming a chamfer at the end of plastics pipes. Generally, these known pipe chamfering tools have an inclined cutting blade and an arrangement for fitting the tool to the end of the pipe in the correct position, so that by relative turning movement between the pipe and the tool, the blade will cut the required chamfer around the periphery of the pipe end. These known tools are often quite complicated in construction and not easy to use, and furthermore only cut a chamfer in the outer face of the pipe.

I have now devised a pipe chamfering tool which is of simple construction and which is straightforward to use, yet produces an accurate chamfer on the end of the pipe, and in addition enables the end of the pipe to be trimmed square in at least some embodiments of the invention.

In accordance with this invention, there is provided a pipe chamfering tool, which comprises a frustoconical member for receiving the end of a pipe to be chamfered, a multiplicity of cutting edges being distributed around the interior face of the frustoconical member.

In use of the pipe chamfering tool according to the invention, the blade member is fitted over the end of the pipe and then by relative movement between the pipe and the tool (for example, by rotation of the pipe and/or the tool), the cutting edges which are distributed around the frustoconical blade member act to cut the chamfer.

The frustoconical member is preferably intermediate between the open and closed ends of a cup-shaped member, and is preferably integral therewith.

Each of the cutting edges is preferably provided adjacent a respective aperture through the wall of the frustoconical member, through which swarf (shavings from the chamfered end of the pipe) ma pass. The apertures are typically formed by punching out metal sheet, leaving a sharp cutting edge adjacent each aperture.

Preferably, a plurality (such as three, four or five) of rows of such apertures are provided, each row- extending substantially around the entire periphery of the fustoconical member. Thus, a length of piping having its end chamfered will progressively contact successive rows of cutting edges as the frustoconical member tapers inwardly. This aids in ensuring that the end of chamfered tubing is cut square.

An embodiment of this invention will now be described, by way of example only, with reference to the accompanying drawing, the single figure of which is a perspective view of a pipe chamfering tool, showing the frustoconical member and cutting edges.

Referring to the drawing, there is shown a pipe chamfering tool which has a generally cup-shaped member 1 having an open end 2 and a closed end 3, and at an intermediate \ position, an integral frustoconical blade portion 4. The blade portion 4 is formed integral with the wall of the cup-shaped member so as to prevent clogging with the swarf.

This blade portion 4 is formed with a large number of cutting edges formed at the edges of apertures 5 which are distributed around the inner face of the blade portion. These apertures 5 are formed by pressing or punching out portions of metal from the blade portion 4 such that the cutting edges are provided on the edges of the pressed-out apertures. The apertures are arranged in several successive longitudinally spaced rows, each row extending right around the periphery of the blade portion 4.

In the illustrated embodiment, the tool is fitted with an eccentic handle 6 which is parallel to the axis of the cup-shaped member, for use in turning the tool relative to the pipe to be chamfered. A handle 6 of the type illustrated is not essential and may in some embodiments be removable; it may even be dispensed with entirely. As an alternative, an integral grip may be pressed into the tool at the time of manufacture.

A different size of tool is required for each size of pipe, but the tools are relatively inexpensive to manufacture and can, -pending on the nature of the handle if present, be nested within each other. The present invention therefore comprises a stack of pipe chamfering tools according to the invention, each one of the tools, except the smallest,

_* having a further such tool nested therein.

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