Tips for pick tools and pick tools comprising same

Patent metadata

Field	Value
Publication number	US-9334730-B2
Application number	US-201214234468-A
Country	US
Kind code	B2
Filing date	Jul 25, 2012
Priority date	Jul 28, 2011
Publication date	May 10, 2016
Grant date	May 10, 2016

Abstract

Tips for pick tools and pick tools comprising same are provided. The tip comprises an impact structure formed joined at a non-planar boundary surface of a substrate. The boundary surface includes a depression. The impact structure comprises super-hard material and has a working end including an apex opposite the depression. The boundary surface of the substrate comprises a ridge at the periphery of the depression and a generally tapered circumferential region depending away from the ridge towards a side of the tip, a lowest point of the depression being directly opposite the apex.

First claim

The invention claimed is:

1. A tip for a pick tool, comprising an
impact structure formed joined at
a non-planar boundary surface of
a substrate comprising cemented carbide material;
the boundary surface
including a depression and comprising
a ridge at the periphery of the depression and
an intermediate region between the ridge and a peripheral edge of the substrate,
the intermediate region depending away from the ridge;
the impact structure comprising
polycrystalline diamond (PCD) material and
a working end having a rounded conical shape, including an apex opposite the depression;
a lowest point of the depression being directly opposite the apex,
the apex and the lowest point of the depression directly opposite the apex defining
a longitudinal axis passing through both;
the apex
defining a radius of curvature in a longitudinal plane of at least 1.5 millimeters; and
the depression
defining a radius of curvature in the longitudinal plane of at least 0.5 millimeter, and
having a depth of 0.1 to 2 millimeters, measured as the longitudinal distance between a highest point on the ridge and the lowest point of the depression.

2. A tip as claimed in claim 1 , in which the longitudinal distance from the apex to a point on the intermediate region of the boundary surface is substantially greater that the longitudinal distance from the apex to the lowest point of the depression.

3. A tip as claimed in claim 1 , in which the ridge surrounds the depression.

4. A tip as claimed in claim 1 , in which the radius of curvature of the depression is less than that of the apex.

5. A tip as claimed in claim 1 , in which the depression defines a radius of curvature in a longitudinal plane of at most 10 millimeters.

6. A tip as claimed in claim 1 , in which the impact structure has a centre thickness between the apex and the boundary surface at the depression, the depression having a maximum lateral diameter less than the centre thickness.

7. A tip as claimed in claim 1 , in which the boundary surface is configured such that the impact structure includes a compressed volume in a residual state of axial compression, the compressed volume extending from the depression in the boundary surface to a region of the impact structure remote from boundary surface.

8. A tip as claimed in claim 7 , in which the compressed volume is at least 10 percent the volume of the tip.

9. A tip as claimed in claim 8 , in which the axial compression is at least 70 megapascals.

10. A pick comprising a tip as claimed in claim 1 .

Assignees

• Sanan Matthew Alan
• Jonker Cornelis Roelof
• Element Six Abrasives Sa

Inventors

• Sanan Matthew Alan
• Jonker Cornelis Roelof

Classifications

• E21C35/18 Primary

  Mining picks; Holders therefor (planing knives E21C27/44) · CPC title

• E21C35/183 Primary

  with inserts or layers of wear-resisting material {(drill bits with wear-resistant parts E21B10/46)} · CPC title

• E21B10/5735

  Interface between the substrate and the cutting element · CPC title

• E21B10/5673

  having a non planar or non circular cutting face · CPC title

• E21B10/46

  characterised by wear resisting parts, e.g. diamond inserts · CPC title