GB2405365A

GB2405365A - Cutting tool

Info

Publication number: GB2405365A
Application number: GB0415676A
Authority: GB
Inventors: Michael Gregory
Original assignee: Cromwell Group Holdings Ltd
Current assignee: Cromwell Group Holdings Ltd
Priority date: 2003-08-28
Filing date: 2004-07-14
Publication date: 2005-03-02
Anticipated expiration: 2024-07-14
Also published as: GB0320105D0; GB2405365B; GB0415676D0

Abstract

A rotary cutting tool or burr (figure 1,10) with a shank for engagement with a power tool and a cylindrical body (figure 1,14) which can be used in the manufacturing sector, medical, dentistry and veterinary professions. The cylindrical body (figure 1,14) has an outer cutting surface provided with a plurality of sets 16, 18, 20 of integral first and second cutting teeth 16, 20 that extend the length of the body (figure 1, 14). The first cutting teeth provide a coarse cut 20 and said second teeth 16 provide a fine cut. Each set of teeth has a coarse cutting tooth as a leading tooth 20 and a fine cutting tooth 16 as a trailing tooth. The cutting teeth 16, 18, 20 may also extend helically along said body (figure 1, 14).

Description

- 1 - 2405365 Cutting Tool The present invention relates to a cutting tool

and particularly to a cutting tool for use with a power tool.

Rotary cutting tools, known as burrs, are used for machining various types of ferrous and non-ferrous metals as well as materials such as fibre glass, hard rubber, plastics, ceramics and hardwood. Three types of rotary cutter are generally available, these being for coarse, standard and fine machining. The to coarse rotary cutting tool produces a rough cut which can be effected quite rapidly whilst the fine cutting tool produces a fine cut which is effected relatively slowly but produces a fine surface as opposed to a roughened surface. The intermediate cutting tool is used to provide an intermediate step between the coarse cut and the fine cut, where necessary.

The present invention seeks to provide an improved rotary cutting tool.

Accordingly, the present invention provides a rotary cutting tool having a shank for engagement with a power tool, and a generally cylindrical body; wherein: said body has an outer, cutting surface provided with a plurality of sets of integral first and second cutting teeth extending the length of said body; said first cutting teeth are adapted to provide a coarse cut and said second cutting teeth are adapted to provide a fine cut; and each said set of cutting teeth has a coarse cutting tooth as a leading tooth and a fine cutting tooth as a trailing tooth.

Preferably, said sets are equi-angularly spaced about said cuttingsurface.

In a preferred embodiment of the invention each said cutting tooth extends helically along said body, and said cutting teeth extend parallel with one another along said body. - 2

Preferably, each tooth in a set extends radially of the body by substantially the same amount.

The present invention is further described hereinafter, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a side elevation of a preferred form of rotary cutting tool according to the present invention; to Figure 2 is an end elevation of the cutting tool of Figure 1 in the direction of arrow A of Figure 1; and Figure 3 is an opposite end elevation of the end cutting tool of Figure 1 in the direction of arrow B. Referring to the drawings, these show a preferred form of cutting tool or burr 10 which has a shank 12 for engagement in the chuck of a power tool. The tool is used primarily for cutting wood, metals, composites and the like. The cutting tool has a cutting head 14 which is provided with a plurality of cutting teeth 16, 18, 20 which are arranged in a spiral formation in the radially outer surface of the cutting tool head 14.

As can be seen from Figures 2 and 3, the cutting teeth are arranged in groups or sets of three, each group being equi-angularly spaced about the periphery of the cutting tool head 14.

In addition, each set of teeth comprises three cutting teeth, 16, 18, 20 with the leading cutting tooth 20 being a coarse cutting tooth and the trailing cutting tooth 16 being a fine cutting tooth. The intermediate cutting tooth 18 may be a fine cutting tooth or a standard cutting tooth, which provides a cut intermediate the coarse cut and the fine cut provided by the teeth 20, 16. - 3

As can be seen from Figure 3 each of the cutting teeth 16, 18, 20 makes a respective angle off, a2, oc3 with the radius of the cutting tool head 14 and in addition each tooth has a cutting depth, d1, d2, d3. Each of these angles and cutting depths can be varied to provide a desired form of cutting action and finished cut in the material being machined.

In use, the cutting tooth rotates in the direction of arrow C as seen in Figures 2 and 3.

As can be seen from Figure 1, the actual end of the cutting tool remote from the shank 12 has a part spherical or curved end with the cutting teeth 16, 18, 20 meeting at the actual centre of the cutting tool. This allows the head of the cutting tool also to be used for milling and grinding.

The cutting tool is conveniently made of high speed steel, tungsten carbide or other suitable material.

The advantage of the cutting tool described with reference to the drawings is that in one pass of the tool it can remove a relatively large amount of material and also provide a fine finish to the material being cut. This avoids the need for separate passes with separate coarse and fine toothed burrs.

Although the preferred form of tool has been described with equiangularly spaced sets of teeth, the sets need not be equi-angularly spaced and could be spaced about the axis of the tool at any suitable desired angles. In addition, whilst each set of teeth is described above as having three teeth, this number may be varied and indeed different sets of teeth on the same tool may have different numbers of teeth. - 4

Finally, the number of fine and coarse cutting teeth in each set may be varied from that described.

Although the tool has been described as primarily being used in the manufacturing sector, it can also be used in the medical, dentistry and veterinary profession on materials such as bone and teeth.

The shape of the tool may also be varied to include spherical tools and other shapes. - 5

Claims

Claims 1 A rotary cutting tool having a shank for engagement with a power

tool, and a generally cylindrical body; s wherein: said body has an outer, cutting surface provided with a plurality of sets of integral first and second cutting teeth extending the length of said body; said first cutting teeth are adapted to provide a coarse cut and said second cutting teeth are adapted to provide a fine cut; and each said set of cutting teeth has a coarse cutting tooth as a leading tooth and a fine cutting tooth as a trailing tooth.
2 A tool as claimed in claim 1 wherein said sets are equi-angularly spaced about said cuttingsurface.
3 A tool as claimed in claim 1 or 2 wherein each said cutting tooth extends helically along said body.
4 A tool as claimed in claim 1, 2 or 3 wherein said cutting teeth extend parallel with one another along said body.
A tool as claimed in any of claims 1 to 4 wherein each tooth in a set extends radially of the body by substantially the same amount.
6 A rotary cutting tool substantially as hereinbefore described with reference to the accompanying drawings.