Coal and rock cutting pick

• US 6,918,636 B2
• Filed: 08/07/2001
• Issued: 07/19/2005
• Est. Priority Date: 08/07/2000
• Status: Expired due to Fees

• Current Assignee: Age Mining Services Pty Limited
• Original Assignee: Age Mining Services Pty Limited
• Inventors: Dawood, Albert Daniel
• Primary Examiner(s): Singh, Sunil
• Application Number:
  US10/344,067
• Publication Number:
  US 20030234569A1
• Time in Patent Office: 1,442 Days
• Field of Search: 299/100, 299/101, 299108-109, 299/112.R, 299/112.T, 299106-107, 299110-111, 299102-105, 299/79.1, 299/87.1
• US Class Current: 299/112.00T
• CPC Class Codes: E21C 35/18 Mining picks; Holders therefor planing knives E21C27/44
• CPC Class Codes: E21C 35/1837 characterised by the shape
• CPC Class Codes: E21C 35/188 characterised by adaptations to use an extraction tool
• CPC Class Codes: E21C 35/19 Means for fixing picks or holders

Abstract

The pick (1) includes a radially inner end (4) and a shank (3) to be fixed to the drum (10) to substantially prevent relative movement between the pick (1) and drum (10). The pick (1) further includes a cutting head (2) having leading (5) and trailing faces (6) intersecting to provide a cutting edge (8) to extend generally parallel to an axis. The leading face (5) in use is inclined by an acute rake angle R to a radius of the axis, with the trailing face (6) being inclined at an acute back clearance angle B to a plane passing through the edge (8) and normal to the radius. The leading face (5) and trailing face (6) being inclined by an acute angle and the shanks when fixed to the drum (10) extends at an acute angle to the radius.

Claims

1. A pick assembly for mounting on a rotatable drum, said drum having a longitudinal axis of rotation, said pick assembly comprising a pick holder and a pick having a longitudinal axis, said pick having:

a non rotating cutting head having a straight cutting edge which delimits substantially planar front and trailing faces of said head;

a securing end engaged within said pick holder to secure said pick relative to said drum so that in use, rotation of said drum drives said cutting edge forward in a generally circular path and so that said pick is prevented from moving substantially relative to said drum; and

a shank extending along said longitudinal axis between said cutting head and said securing end,

said pick assembly being oriented such that said trailing face is inclined at an acute back clearance angle of about 7 to 15 degrees to a cutting plane, which is defined by a tangent to said circular path at said cutting edge, said front face is inclined at an acute front rake angle of about 10 to 45 degrees to an axis perpendicular to said cutting plane such that said front and trailing faces define an acute angle at said cutting edge, and said cutting edge is maintained in a fixed orientation relative to said drum and substantially parallel to said longitudinal axis; and

characterised in that both said front and trailing faces converge outwardly with respect to said drum toward said longitudinal axis of extension and wherein said pick and said pick holder are adapted so that said longitudinal axis is inclined by an acute angle extending rearwardly to said cutting plane.

2. The pick assembly according to claim 1, wherein said shank has a substantially circular cross section and said securing end has a circumferential groove.

3. The pick assembly according to claim 1, wherein securing end has a cross section in the shape of a circle with a segment cut away.

4. The pick assembly according to claim 1, 2, or 3, wherein said pick is manufactured from an air-hardened die cast steel.

5. The pick assembly according to claim 1, 2, or 3, wherein the back clearance angle is between 8 and 10 degrees.

6. The pick assembly according to claim 1, 2 or 3, wherein the rake angle is between 10 and 30 degrees.

7. The pick assembly according to claim 1, 2, or 3, wherein the width of the cutting edge is between 5 millimetres and 60 millimetres.

8. The pick assembly of claim 1, wherein said cutting edge is displaced from said axis of extension.

9. A rotatable drum having at least one pick holder and at least one cutting pick mountable in said pick holder, said pick having a longitudinal axis and including:

a non rotating cutting head having a straight cutting edge which delimits substantially planar front and trailing faces of said head;

a securing end engaged within said pick holder to secure said pick to said drum so that in use, rotation of said drum drives said cutting edge forward in a generally circular path and so that said pick is prevented from moving substantially relative to said drum; and

a shank extending along said longitudinal axis between said cutting head and said securing end,

said pick being oriented in said pick holder such that said trailing face is inclined at an acute back clearance angle of about 7 to 15 degrees to a cutting plane which is defined by a tangent to said circular path at said cutting edge, said front face is inclined at an acute front rake angle of about 10 to 45 degrees to an axis perpendicular to said cutting plane such that said front and trailing faces define an acute angle at said cutting edge, and said cutting edge is maintained in a fixed orientation relative to said drum and substantially parallel to said longitudinal axis; and

characterised in that both said front and trailing faces converge outwardly with respect to said drum toward said longitudinal axis of extension and wherein said pick and said pick holder are adapted so that said longitudinal axis is inclined by an acute angle extending rearwardly to said cutting plane.