AU600501B2

AU600501B2 - Cutting element for a mining machine

Info

Publication number: AU600501B2
Application number: AU76732/87A
Authority: AU
Inventors: Klaus Tank; Peter Noel Tomlinson
Original assignee: De Beers Industrial Diamond Division Pty Ltd
Current assignee: De Beers Industrial Diamond Division Pty Ltd
Priority date: 1986-08-11
Filing date: 1987-08-10
Publication date: 1990-08-16
Anticipated expiration: 2007-08-10
Also published as: BE1000203A4; FR2602541B3; GB8718896D0; DE8710722U1; GB2193740A; AU7673287A; FR2602541A1; GB2193740B

Description

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COMNONW U-LTIi OF AUSTRALI6 o' 5 u' PATENTS ACT 1952-IQ62 CO0M P L ETE S P EC IrFIC A T 1 0 (Original) FOR OFFICE USE Class Int. Class Application Number: Lodged: Complete Specification Lodged: Accepted: Published: Prior ity Related Art: This docum: nt contains the amendments made under Section 49 and is correct for printing.

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Name of Applicant: Address of Applicant: Actual Inventor(s): Address for Service: DE BEERS INDUSTRIAL DIAMOND DIVISION (PROPRIETARY) LIMITED 45 Main Street, Johannesburg, Transvaal, SOUTH AFRICA 1 PETER NOEL TOMLINSON 2KLAUS TANK DAVIES COLLISON, One Little CoV'ins Street, Melbourne 3000, AUSTRALIA Complete Specification for the invention entitled: "1CUTTING ELEMENT FOR A MINING MACHINE" The following statement is a full description of this invention. including the best method of performing it known to :0/us: 00 o 00 0 00 00 00 0 0 0 000 0 00 0 0 0 0000 0 0 0 0 So BACKGOUND OF THE INVENTION 0 0o 0 This invention relates to cutting elements for us?- in mining S00: machines of the type which are used to cut a variety of soft materials such as coal.

q0o000 5 In mining machines of this type, a plurality of outting tools (also v000 known as picks) are positioned on a working surface, for example the 000004 0 0 surfacL of a drum, and moved in a cutting direction against the face of the material to be cut. Each tool comprises a holding lug and a cutting element secured in a bore or socket in the lug. The cutting element may be made of a wear resistant material such as cemented carbide. Alternatively, the cutting element may comprise an elongate pin one end of which has secured to it an abrasive compact which provides a cutting edge for the element.

3 SUMMARY OF THE INVENTION According to the present invention, there is provided a cutting element for a cutting tool of a mining machine of the type described above comprising a supporting pin, one end of which is adapted to be located in a socket in the cutting tool and the opposite end of which has bonded thereto an abrasive compact, the abrasive compact presenting a bevcllCd -utting -edge. Mfljor -/Cf surface havI c beve?(W ferip"era/ cuiiVj ex DESCRIPTION OF THE DRAWING Figure 1 illustrates a side view of an embodiment of a cutting element of the invention; and Figure 2 illv.strates a perspective view of a cutting tool including the cutting element of Figure 1.

DETAILED DESCRIPTION OF THE INVENTION The supporting pin which carries the abrasive compact is preferably made of cemented carbide, typically cemented tungsten carbide.

The abrasive compact will generally be provided in the form of a disc which provides a circular, bevelled cutting edge. The abrasive compact may be any known 'n the art. Abrasive compacts consist essentially of a mass of abrasive particles present in an amount of at least 70%, preferably 80 to 90% by volume of the compact bonded into a hard conglomerate. Compacts are polycrystalline masses and can replace single large crystals, The abrasive particles of compacts are invariably ultra-hard abrasives such as diamond and cubic boron nitride.

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-i-ii.iin.ii,_ji^L.-ilii__ L-i-iniii. 1^ -4- Diamond and cubic boron nitride compacts are manufactured under conditions of temperature and pressure at which the abrasive particle is crystallographically stable. Consequently, compacts include a considerable amount of direct particle-to-particle bonding.

The abrasive compact may be bonded to a cemented carbide support.

Such bonded abrasive compacts are known in the art as composite abrasive compacts. Composite abrasive compacts and their method of manufacture have been described extensively in the patent literature, for example United States Patents No. 3,743,489, 3,767,371, 4,063,909, and 3,745,623.

The abrasive compact or composite abrasive compact will preferably be located in a recess formed in one end of the supporting pin. The shape of the pin is preferably such that it provides a shoulder surrounding the recess and sloping away from it.

Bonding of the abrasive compact or composite abrasive compact to the supporting pin may be achieved by methods known in the art, for example brazing.

An embodiment of the invention will now be described with reference to the accompanying drawing. Referring to Figure 1 of this drawing, there is shown a cutting element comprising a supporting pin 10 made of cemented carbide. The supporting pin has formed at one end 12 thereof a recess 14 in which is located a composite abrasive compact 16. The composite abrasive compact comprises an abrasive compact layer 18 bonded to a cemented carbide support 20. The cemented carbide support 20 is bonded to the supporting pin by means of a suitable braze. The abrasive compact layer 18 presents a bevelled 5 cutting edge 22. The bevelled edge 22 has the advantage over the sharp edge of prior art cutting elements in that the tendency for chipping to occur is minimised.

Sloping away from the recess is a shoulder 24 which surrounds the recess completely. The shoulder leads to a widened zone 26 which in turn leads to a lower narrower zone 28. In use, the supporting pin is located in a socket in a cutting tool for a mining machine in the manner illustrated by 'igure 2. Referring to this figure, the cutting tool comprises a holding lug 30, one end 32 of which is shaped for mounting in the drum surface of a conventional mining machine and the other end 34 of which provides a working surface 36.

A socket 38 is formed in the working surface 36. The supporting pin is located in the socket such that the zones 26 and 28 fit wholly within the socket which has complementally shaped zones. The pin may be secured in the socket by brazing.

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Claims

1. A cutting element for a cutting tool of a mining machine of the type used to cut soft materials comprising a supporting pin, one end of which is adapted to be located in a socket in the cutting tool and the opposite end of which has bonded thereto an abrasive compact, the abrasive compact presenting a bevelled cutting edge.- /A,1or -44 Srah e h'avno beve-ec{ er(pAerl cuHif~y eelge. S2. A cutting element of claim 1 wherein the abrasive co,.:pact is the 10 compact layer of a composite abrasive compact.

4. I 9 3. S A cutting element of claim 1 or claim 2 wherein the abrasive compact or composite abrasive compact is located in a recess formed in one '9 0 e A cutting element of any one of the preceding claims wherein the abrasive compact is a diamond compact. «f~i~sA cutting element of any one of the preceding claims wherein the supporting pin is made of cemented carbide.

6. A cutting element of claim 1 substantially as herein described with reference to the accompanying drawing. o 4 suprigpn smd fcmetdcrie I^GS 6. A utn lmn fcli usatal s eendsrbdwt referenceto-the-acompanyin-drawing -7- -The- s-te e-i-&sed&-he-re-i n- or any Dated this 10th day of AUGUST, 1987 DE BEERS INDUSTRIAL DIAMOND DIVISION (PROPRIETARY) LIMITED By Its Patent Attorneys DAVIES COLLISON t t