GB1581226A

GB1581226A - Rotary cutting and/or grinding tools

Info

Publication number: GB1581226A
Application number: GB1867176A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1977-08-08
Filing date: 1977-08-08
Publication date: 1980-12-10

Description

(54) IMPROVEMENTS IN OR RELATING TO ROTARY CUTTING AND/OR GRINDING TOOLS (71) I, JAMES FRANCIS THOMAS, a British Subject of 29 Colwyn Crescent, Colwyn Bay, Clwyd, LL28 4RH, North Wales, do hereby declare the invention for which I pray that a patent may be granted to me, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to rotary cutting and/or grinding tools.

In particular the present invention is concerned with cutting and/or grinding tools with abrasive working surfaces.

The abrasive tool of the present invention is particularly applicable to use in squeegee dressing apparatus as disclosed in my copending Application No. 27137/75. (Serial No. 1566547).

However, the use of the tool of the present invention is not limited to this particular use and could find uses in other circumstances.

Broadly, in accordance with a first aspect of the present invention there is provided a rotary cutting and/or grinding tool adapted for cutting or grinding action in either direction of rotation and comprising a substantially cylindrical element provided with a plurality of circumferentially spaced grooves in its external surface, with lands between the grooves coated with abrasive material said element including means for assisting the cooling of the tool when in use.

A second aspect of the invention provides a rotary cutting and/or grinding tool, including a body adapted for mounting upon an arbor or shaft for rotation thereby, said body being provided with a plurality of lands or islands, and with means for assisting the cooling of the tool when in use, each such land or island being coated with an abrasive material.

Preferably the abrasive material is a material having a hardness in excess of seven Moh on the conventional hardness scale.

Conveniently the abrasive material is diamond.

The abrasive material can comprise other materials such as tungsten carbide, silicon carbide, aluminous oxide, garnet, glass or other suitable materials.

These abrasive materials can either be used separately or in suitable mixtures according to operational characteristics desired.

Thus when it is desired to produce a very fine surface by the use of a tool incorporating the features of the invention the abrasive surface produced by the application of the abrasive material on the tool body may be dressed during manufacture, so that any irregular spikes are reduced to, the average level of the abrasive coating. The abrasive characteristics of the coating as affected by the mesh size of the abrasive material, the layer or coating thickness of the bonding material etc., can be determined experimentally for especial purposes.

It has been found that the application of diamond abrasive material on the body is conveniently effected by means of an electroplating method since this method provides a wide, if not the widest, field of tolerance and performance For a better understanding of the invention and to show how to carry the same into effect reference will now be made to the accompanying drawing, in which, Figure 1 is a side elevation of a rotary cutting and/or grinding tool incorporating features of the invention, and Figure 2 is an end elevation of the tool of Figure 1 the Figure illustrating three alternative cross-sections for a detail of the tool.

The rotary cutting and/or grinding tool shown in the Figures can be conveniently regarded as an abrasive wheel or hob and as shown in the drawing comprises a cylindrical element 10 of, for example mild steel, which is bored at 12 to enable it to be fitted upon a suitable shaft or arbor i.e., a motor shaft (not shown). It will be understood that the bore 12 could be tapered in accordance with any of the conventional tool/arbor tapers for example a Morse taper. The tool can be conveniently held in place by a screw 13 engaging in a suitable bore.

The wheel 10 is counterbored as at 14 in order to reduce wall thickness over this region in order to assist air cooling of the wheel during use. The wheel 10 is provided with a plurality of axially extending grooves or slots in its external surface thereby to leave axially land surfaces therebetween and thus provide a fluted appearance.

Three alternative groove cross sections are shown in Figure 2, an arcuate cross-section 16a which is the presently preferred form, a substantially rectangular cross-section 16b, and a trapezoidal cross-section 16c. The arcuate grooves can be readily formed by making the element oversize and by then drilling holes at the positions at which the arcuate grooves are desired. The excess material is removed so as to provide the grooves 16a. The land surfaces 18 between the grooves are coated with an appropriate abrasive material of those previously mentioned or a mixture thereof. As has been mentioned the material can be applied to the lands by an electroplating process.

As has been indicated the diameter of the body and the number and shape of the grooves 16 and the dimensions of the lands 18 should not be considered as limited to the various illustrated embodiments but may vary widely in dependence upon the particular application and mode of use of the tool that is wheel.

A primary purpose is to achieve air cooling of the wheel when in use and also to provide a groove shape which will reduce loading of the abrasive surface by abraded particles.

The cooling effect can be enhanced by providing through bores in the grooves at convenient locations, i.e., adjacent to the inner end of the groove.

Furthermore, although the wheel illustrated is shown as having grooves extending axially, the grooves may alternatively, for example, extend at an angle down the outside surface of the wheel. Thus, for example, the grooves may be effectively helical.

In a further embodiment (not shown) the tool can be formed with intersecting grooves so that the lands effectively become islands.

It will be appreciated that the shape and number of islands will be related to the number of grooves and the relative angular relationships between the grooves.

If desired air deflector arrangements (not shown) can be provided in the counterbored portion 14 to increase the flow of air into the interior of the tool.

It will be understood that the outer surface of the tool could be tapered i.e., so that the resulting tool shape can be regarded as a conic frustum. When the body of the tool is tapered and the grooves are linear each adjacent pair of channels or grooves at corresponding locations along the axial length of the tool have the same between groove separation.

In other words the grooves or channels are equiangularly spaced.

WHAT I CLAIM IS: 1. A rotary cutting and/or grinding tool adapted for cutting or grinding action in either direction of rotation, and comprising a substantially cylindrical element provided with a plurality of circumferentially spaced grooves in its external surface, with the lands between the grooves coated with abrasive material, said element including means for assisting the cooling of the tool when in use.

2. A rotary cutting and/or grinding tool, including a body adapted for mounting upon an arbor or shaft for rotation thereby, said body being provided with a plurality of lands or islands and with means for assisting the cooling of the tool when in use, each such land or island being coated with a layer of abrasive material.

3. A rotary cutting and/or grinding tool as claimed in claim 2, wherein the tool is capable of cutting and/or grinding action in both directions of rotation.

4. A rotary cutting and/or grinding tool as claimed in claim 2 or 3, wherein the lands or islands are provided by providing grooves or channels in the body.

5. A rotary cutting and/or grinding tool as claimed in claim 2, 3 or 4, wherein the body is substantially cylindrical.

6. A rotary cutting and/or grinding tool as claimed in any claim 2, 3 or 4, wherein the body is tapered.

7. A rotary cutting and/or grinding tool as claimed in claim ,4,5 or 6, wherein the grooves or channels are equiangularly disposed around the body.

8. A rotary cutting and/or grinding tool as claimed in any one of claims 2 to 7, wherein the grooves or channels are arranged lengthwise of the body, and parallel to the axis thereof.

9. A rotary cutting and/or grinding tool as claimed in any one of claims 2 to 7, wherein the grooves or channels are inclined relative to the axial direction of the body.

10. Arotary cutting and/ or grinding tool as claimed in any one of claims 2 to 9, wherein the grooves or channels have an arcuate cross-sectional profile.

11. A rotary cutting and/or grinding tool as claimed in any one of claims 2 to 9, wherein the grooves or channels have an angular cross-sectional profile.

12. A rotary cutting and/or grinding tool as claimed in any one of the preceding claims wherein the abrasive material comprises a

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. shown). It will be understood that the bore 12 could be tapered in accordance with any of the conventional tool/arbor tapers for example a Morse taper. The tool can be conveniently held in place by a screw 13 engaging in a suitable bore. The wheel 10 is counterbored as at 14 in order to reduce wall thickness over this region in order to assist air cooling of the wheel during use. The wheel 10 is provided with a plurality of axially extending grooves or slots in its external surface thereby to leave axially land surfaces therebetween and thus provide a fluted appearance. Three alternative groove cross sections are shown in Figure 2, an arcuate cross-section 16a which is the presently preferred form, a substantially rectangular cross-section 16b, and a trapezoidal cross-section 16c. The arcuate grooves can be readily formed by making the element oversize and by then drilling holes at the positions at which the arcuate grooves are desired. The excess material is removed so as to provide the grooves 16a. The land surfaces 18 between the grooves are coated with an appropriate abrasive material of those previously mentioned or a mixture thereof. As has been mentioned the material can be applied to the lands by an electroplating process. As has been indicated the diameter of the body and the number and shape of the grooves 16 and the dimensions of the lands 18 should not be considered as limited to the various illustrated embodiments but may vary widely in dependence upon the particular application and mode of use of the tool that is wheel. A primary purpose is to achieve air cooling of the wheel when in use and also to provide a groove shape which will reduce loading of the abrasive surface by abraded particles. The cooling effect can be enhanced by providing through bores in the grooves at convenient locations, i.e., adjacent to the inner end of the groove. Furthermore, although the wheel illustrated is shown as having grooves extending axially, the grooves may alternatively, for example, extend at an angle down the outside surface of the wheel. Thus, for example, the grooves may be effectively helical. In a further embodiment (not shown) the tool can be formed with intersecting grooves so that the lands effectively become islands. It will be appreciated that the shape and number of islands will be related to the number of grooves and the relative angular relationships between the grooves. If desired air deflector arrangements (not shown) can be provided in the counterbored portion 14 to increase the flow of air into the interior of the tool. It will be understood that the outer surface of the tool could be tapered i.e., so that the resulting tool shape can be regarded as a conic frustum. When the body of the tool is tapered and the grooves are linear each adjacent pair of channels or grooves at corresponding locations along the axial length of the tool have the same between groove separation. In other words the grooves or channels are equiangularly spaced. WHAT I CLAIM IS:

1. A rotary cutting and/or grinding tool adapted for cutting or grinding action in either direction of rotation, and comprising a substantially cylindrical element provided with a plurality of circumferentially spaced grooves in its external surface, with the lands between the grooves coated with abrasive material, said element including means for assisting the cooling of the tool when in use.

material having a hardness in excess of seven Mohs on the conventional hardness scale.

13. A rotary cutting and/or grinding tool as claimed in any one of the preceding claims wherein the abrasive material comprises diamond, tungsten carbide, silicon carbide, aluminous oxide, garnet, glass or the like.

14. A rotary cutting and/or grinding tool as claimed in claim 13, wherein the abrasive material comprises a mixture of two or more different abrasive materials.

15. A rotary cutting and/or grinding tool as claimed in any one of the preceding claims, wherein the means for assisting the cooling of the tool includes a bore extending lengthwise of the body of the tool.

16. A rotary cutting and/or grinding tool as claimed in claim 15 and including transversely directed bores connecting with the bore extending lengthwise of the tool and connecting with the grooves.

17. A rotary cutting and/or grinding tool as calimed in claim 15 or 16 and including air deflector means in the bore extending lengthwise of the tool.

18. A rotary cutting and/or grinding tool, constructed and arranged to operate substantially as hereinbefore described with reference to the accompanying drawing.