GB2288557A

GB2288557A - Grinding wheel having grinding surface about circumferential edge made of preformed grinding elements secured to disc

Info

Publication number: GB2288557A
Application number: GB9408061A
Authority: GB
Inventors: Brian Douglas Lindow; Jeffrey Scott Wirth
Original assignee: Unicorn Abrasives Ltd
Current assignee: Unicorn Abrasives Ltd
Priority date: 1994-04-22
Filing date: 1994-04-22
Publication date: 1995-10-25
Anticipated expiration: 2014-04-22
Also published as: GB2288557B; GB9408061D0

Abstract

The elements P1, P2 are mounted in rows and abutted in side by side relationship, the adjacent elements being of different widths so that the joint line in the circumferential direction is discontinuous. The elements are of bonded abrasive particles, and are cold pressed, hot-pressed to the disc periphery. The wheel does not leave a grinding mark on workpieces. <IMAGE>

Description

GRINDING TOOL AND METHOD OF ASSEMBLY The invention relates to a grinding tool, in particular a wheel. Such an article consists of a support disc, e.g. metal, ceramic or plastic, having at its periphery a continuous rim of abrasive material. It is difficult to make a wheel of relatively large thickness having a band of such grinding elements about its circumference. It is usual therefore to make a laminate comprising thin wheel layers each having band of the elements, the layers being bonded together in such a way that the joint lines are inclined to the major axis of the laminate so that the joint lines do not leave a telltale mark on the workpiece being treated.

It is one object of the invention to provide a grinding wheel of relatively large thickness which does not leave a grinding mark on the workpiece being treated. It is a further object of the invention to provide a simple method of making such a wheel.

In one aspect the invention provides a grinding wheel comprising a generally disclike body having a grinding surface about the circumferential edge, wherein the surface comprises a plurality of preformed grinding elements secured to the body, the elements being abutted in side-by-side relation, the joint line of abutting elements in the circumferential direction being discontinuous.

In another aspect the invention provides a method of making a grinding wheel comprising a circular body having a grinding surface about the circumferential edge, the method comprising; providing a plurality of grinding elements having substantially the same length but different widths; mounting the elements on the circumference of the body to form a band and to provide the grinding surface, with the lengths of the elements being, generally parallel to the circumferential axis of the wheel, the elements being abutted together in side-by-side relation so that adjacent elements define a joint line in the circumferential direction, adjacent elements being of different widths so that the joint line is discontinuous.

In yet another aspect the invention includes a method of grinding a substrate using a grinding wheel as disclosed herein.

Preferably the platelets are mounted in rows in each of which the platelets of different widths alternate, the platelets of one row being staggered relative to the other. As a result the joint line in the circumferential direction where adjacent platelets abut is discontinuous.

The grinding elements may be made of natural or synthetic materials, e.g. silicon carbide, alumina, CBN, natural or synthetic diamond; or the like. The particles making up the elements may be bonded using a vitrified, silicate, resin or'like bonding agent. The elements may be cold pressed, hot-pressed or otherwise secured as a band to the disc periphery.

The disc may range from about 20 mm to about 500 mm or more in thickness.

The grinding wheel may be used to grind a wide range of materials such as metal or alloy castings; hard steels, ceramics, stones; and the like.

In order that the invention may be well understood it will now be described by way of example only with reference to the accompanying diagrammatic drawings, in which Figure 1 is a perspective view of a grinding wheel of the invention Figure 2 is an enlarged front view of the circumferential edge thereof.

The wheel W comprises a circular disc D of metal, e.g. aluminium or steel, measuring say 5 cm thick. The centre of the disc D has a hub by which it is mounted on a spindle, not shown, in the usual way. At its rim the wheel is provided with a generally annular band B which is a grinding surface. The surface is defined by platelets P of bonded abrasive material e.g. alumina, CBN, silica or silicon carbide. The platelets are of two types having the same length L and thickness but which differ in their width, some platelets type P1 having a width W1 which is less than that of the other platelets type W2. The platelets are secured, e.g. adhered by cold or hot set resin to the body. The platelets are mounted in two rows R1, R2 as shown so that platelets P1 and P2 alternate in each row. Because the platelets are of different widths the joint line J in the direction of the circumferential axis is discontinuous, i.e. it is not a straight line. As a result when the wheel is used to grind a workpiece the band B cannot leave a continuous telltale line.

The invention is not limited to the embodiment shown. For example the platelets need not be oblong as seen in plan; more than two rows may be present.

Claims

1. A grinding wheel comprising a generally disc-like body having a grinding surface about the circumferential edge, wherein the surface comprises a plurality of preformed grinding elements secured to the body, the elements being abutted in side-by-side relation, the joint line of abutting elements in the circumferential direction being discontinuous.

2. A wheel according to Claim 1, in which the elements are platelets which are mounted in rows in each of which the platelets of different widths altemate, the platelets of one row being staggered relative to the other.

3. A method of making a grinding wheel comprising a generally disc like body having a grinding surface about the circumferential edge, the method comprising; providing a plurality of grinding elements having substantially the same length but different widths; mounting the elements on the circumference of the body to form a band and to provide the grinding surface, with the lengths of the elements being, generally parallel to the circumferential axis of the wheel, the elements being abutted together in side-by-side relation so that adjacent elements define a joint line in the circumferential direction, adjacent elements being of different widths so that the joint line is discontinuous.