GB2148353A - Mining picks - Google Patents

Abstract

A mining pick has a steel body 10 and a cylindrical diamond compact 13 as a cutting tip. The compact 13 is embedded lengthwise in a recess in a backing 12 made of cemented tungsten carbide. <IMAGE>

Description

SPECIFICATION Mining picks Background to the invention This invention relates to mining picks of the kind used in mining machines for coal and other minerals and in machines for road planing.

In general a pick of the kind in question has an elongated body with a tip which performs the cutting action.

It has already been proposed to form the cutting section of the tip from a diamond compact - see SA patent No. 80/5766. In this prior proposal the cutting pick is formed in three parts secured together: the tip, a hard alloy such as stellite backing the tip and the main body of the tip made of steel.

Tips of cemented tungsten carbide embedded in steel bodies have also been disclosed - see US patent No. 3,650,565.

It is an object of the invention to improve on the use of diamond compacts in mining picks.

Summary of the invention According to the invention a mining pick having an elongated steel body with a diamond compact as a cutting tip, the tip being backed by a material harder than the body has the improvement that the backing material is cemented hard metal, preferably tungsten carbide, and that the compact is embedded longwise in a recess in the hard metal.

Description of the drawings Figure 1 is a pick bit according to the invention, and Figure 2 is a view of another kind of bit according to the invention.

Description of embodiments Figure 1 shows a bit of the kind illustrated, e.g.

in US patent specification No. 4 084 856 modified by the teachings of the present invention. The bit has a body 10 to which is brazed along a line 11 to a cemented tungsten carbide portion 12. The forward end of the portion 12 is formed with a cylindrical blind hole in which is accommodated, by brazing or infiltration, a cylindrical diamond compact 13.

Figure 2 shows a pick of the kind illustrated in British patent specification No. 1170 979 and comprises a body 20 to which is secured a tungsten carbide section 21 and which section carries a cylindrical diamond compact 23.

In practice the portion 12 and the section 21 wear in step with the compact 13 or 23.

1. A mining pick having an elongated steel body with a diamond compact as a cutting tip, the tip being backed by a material harder than the body with the improvement that the backing material is a cemented hard metal, and that the compact is embedded longwise in a recess in the hard metal.

2. The pick claimed in claim 1 in which the hard metal is cemented tungsten carbide.

3. The pick claimed in either one of claims 1 or 2 in which the compact is cylindrical.

4. A mining pick substantially as herein described with reference to Figures 1 or 2.

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

Claims (4)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Mining picks Background to the invention This invention relates to mining picks of the kind used in mining machines for coal and other minerals and in machines for road planing. In general a pick of the kind in question has an elongated body with a tip which performs the cutting action. It has already been proposed to form the cutting section of the tip from a diamond compact - see SA patent No. 80/5766. In this prior proposal the cutting pick is formed in three parts secured together: the tip, a hard alloy such as stellite backing the tip and the main body of the tip made of steel. Tips of cemented tungsten carbide embedded in steel bodies have also been disclosed - see US patent No. 3,650,565. It is an object of the invention to improve on the use of diamond compacts in mining picks. Summary of the invention According to the invention a mining pick having an elongated steel body with a diamond compact as a cutting tip, the tip being backed by a material harder than the body has the improvement that the backing material is cemented hard metal, preferably tungsten carbide, and that the compact is embedded longwise in a recess in the hard metal. Description of the drawings Figure 1 is a pick bit according to the invention, and Figure 2 is a view of another kind of bit according to the invention. Description of embodiments Figure 1 shows a bit of the kind illustrated, e.g. in US patent specification No. 4 084 856 modified by the teachings of the present invention. The bit has a body 10 to which is brazed along a line 11 to a cemented tungsten carbide portion 12. The forward end of the portion 12 is formed with a cylindrical blind hole in which is accommodated, by brazing or infiltration, a cylindrical diamond compact 13. Figure 2 shows a pick of the kind illustrated in British patent specification No. 1170 979 and comprises a body 20 to which is secured a tungsten carbide section 21 and which section carries a cylindrical diamond compact 23. In practice the portion 12 and the section 21 wear in step with the compact 13 or 23. CLAIMS

1. A mining pick having an elongated steel body with a diamond compact as a cutting tip, the tip being backed by a material harder than the body with the improvement that the backing material is a cemented hard metal, and that the compact is embedded longwise in a recess in the hard metal.

2. The pick claimed in claim 1 in which the hard metal is cemented tungsten carbide.

3. The pick claimed in either one of claims 1 or 2 in which the compact is cylindrical.

4. A mining pick substantially as herein described with reference to Figures 1 or 2.