GB2182698A - Mineral cutter pick - Google Patents

Abstract

A mineral cutter pick 1 comprises a head 2 having a hard material cutter tip 3, and a shank 4 extending from the head 2, by which shank 4 the pick 1 is releasably secured in an aperture 5, of cross- section corresponding to that of the shank 4, of a pick box 6, the pick 1 being provided with a water supply bore 11 having a water discharge end 12, and a deflector 19, 19A, 19B carried by the pick 1 and being so formed and located as, in use, to deflect water 23 emerging from the discharge end 12 towards the so- called incendive sparking area 25, in a predetermined water spray configuration. <IMAGE>

Description

SPECIFICATION Mineral cutter pick This invention relates to a mineral cutter pick having a head provided with a hard material, e.g. tungsten carbide, cutting tip, and being releasably located by means of a shank, in a pick box or holder secured to a rotary cutting head of a mineral winning machine, e.g. a shearer, to an underground roadway or tunnel driving machine, e.g. a road header, to a cutter chain, or to a mineral plough etc.

In recent years there have been various proposals to provide a water supply, in the form of a spray or jet, in an area behind the tip (having regard to the direction of movement of the pick in use) to reduce or eliminate the so-called incendive sparking, which is a safety hazard if coal mining is involved. The majority of proposals have involved the drilling of a water supply bore along the pick, with a bore discharge end emerging where water emission is required. It has also been practice to secure a water discharge nozzle at the end of the bore, the nozzle having a water outlet orifice selected to provide the configuration of water spray or jet required e.g. pencil jets, fan sprays, conical sprays, but tests have shown that irrespective of the location of the discharge end and the selected orifice, damping or containment of incendive sparks cannot be guaranteed.

The object of the present invention is to provide a mineral cutter pick with improved water effectiveness at the incendive sparking area.

According to the present invention, there is provided a mineral cutter pick comprising a head having a hard material cutter tip, and a shank extending from the head, by which shank the pick is releasably securable in an aperture, of cross-section corresponding to that of the shank, of a pick box or holder, the pick being provided with a water supply bore having a water discharge end, and a deflector carried by the pick and being so formed and located, as, in use, to deflect water emerging from the discharge end towards the so-called incendive sparking area, in a pre-determined water spray configuration.

Thus, with the pick in accordance with the invention, the deflector rather than the water outiet orifice determines the configuration of the water spray projected towards and along the incendive sparking area, and there are certain advantageous possibilities with the adoption of this principle.

In a first embodiment, the deflector, or at least its inner profile, may be semicircular, or generally so, to produce a horse-shoe shaped spray, which diverges from the deflector, this being particularly advantageous where the pick is a shearer pick for instance, for such a spray configuration forms a shroud or tunnel along the incendive sparking area to contain and damp any sparks generated within the shroud.

In a second embodiment, the deflector, or at least its inner profile, may be rectangular, to produce a wedge-shaped spray, diverging from the deflector.

In a third embodiment, the deflector, or at least its inner profile, may be circular, to produce a conical spray, diverging from the deflector.

The spray configuration, of whatever configuration may be hollow or, to saturate the incendive sparking area, may be "solid".

It will be appreciated that there are many industry-standard picks of various shapes and sizes that are usually produced by forging, and consequently the modification of such a standard pick in accordance with the principle of the invention, requires, apart from the drilling of the water supply bore which may already be present, the attachment of the deflector by any convenient means. Thus, as the deflector may be metallic, e.g. of steel, or of synthetic plastics material, it may be attached to the pick by welding, by screwing into a suitably tapped hole, or as a push-fit, or as a knock-in fit. With whatever manner of attachment is employed, the deflector may be positioned so as to be located wholly externally of the pick, wholly internally of the pick, or partially inter nally and partially externally.Alternatively, instead of modifying a standard pick, for a construction in which the deflector projects, or partially projects, from the pick, the deflector may be produced initially as a projection, as part of the pick forging, with the projection subsequently machined, e.g. by simple drilling, to produce a water deflecting surface of profile to provide the desired water spray configuration. For any arrangement of deflector, this is conveniently positioned opposite the discharge end of the water supply bore. Furthermore, the discharge end of the water supply bore may emerge at the pick head i.e. in a rearward face of the head having regard to the direction of movement of the pick in use, and/or at a so-called heel of a radical type pick.Provided sufficient water capacity is available, the location of a first deflector on the head, and a second deflector on the heel would clearly provide a greater containment/damping effect over the incendive sparking area.

With any embodiment of deflector which projects at least partially from the pick, the deflector preferably has open forward and rearward ends, so that should the deflector interior become filled with debris, then the latter can readily be cleared simply by pushing a tool, e.g. a screwdriver blade, through the deflector.

In a simple form of deflector in accordance with the first embodiment, the deflector may be produced as a short length of steel tube, with the short length then cut axially in two, to produce two semi-circular deflectors, limbs of which are weldable to the head or heads of a pick.

The pick may be of a kind in which the water supply bore is a water conveying bore, but preferably the pick is of a kind disclosed in our EU Application No. 85303118.5, wherein water pressure is not applied to the bore, but is confined within a lance, e.g. of flexible synthetic plastics material, of length approximating to that of the bore and carrying, adjacent the discharge end of the bore, a water spray nozzle, with water emitted from the nozzle impinging upon the deflector, to be deflected and shaped to the spray configuration required along the incendive sparking area.

The invention will now be described in greater detail, by way of examples, with references to the accompanying drawings, in which: Figure 1 is an axial section view through a first embodiment of pick in accordance with the invention shown mounted in a pick box; Figure 2 is an end elevation of the shank of the pick, in the direction of arrow A; Figure 3 is a view of a portion of the head of the pick, in the direction of arrow B; Figure 4 is a representation of the spray configuration produced by the deflector of Figures 1-3; Figure 5 corresponds to Figure 3 but shows a second embodiment; Figure 6 is a representation of the spray configuration produced by the deflector of Figure 5; Figure 7 also corresponds to Figure 3 but shows a third embodiment; and Figure 8 is a representation of the spray configuration produced by the deflector of Figure 7.

In the drawings, is illustrated a mineral cutter pick 1 being, in its basic construction, an industry-standard, radial type pick, comprising a pick head 2 provided with a hard material, e.g. tungsten carbide, cutting tip 3, and a rectangular section shank 4 by which the pick 1 is releasably retained within a rectangular section aperture 5 of a pick box 6 which is secured by welding to a rotary cutting head 7, the pick 1 seating on an upper bearing face 8 of the pick box 6 by means of a forward shoulder 9 and a rearward heel 10, "forward" and "rearward" being with respect to the anti-clockwise direction of rotation, in use, of the cutting head 7.

The pick 1 has been modified to a form described and illustrated in our EU Patent Application 85303118.5, in that a water supply bore 11 has been drilled through a portion of the rearward side of both the shank 4 and head 2, the bore 11 having a discharge end 12 located in a rearward face 13 of the head 2, and a slot 14 has been machined into the rearward side of the shank 4, the slot 14 intersecting an inlet end 15 of the bore 11.

Releasably secured to the rotary cutting head 7 by means of a connector 16 is a flexible, water supply lance 17, e.g. of nylon, which terminates remote from the connector 16 in a metallic water spray nozzle 18. In the embodiment of Figure 1 a deflector 19 is secured by welding to the rearward face 13 of the cutting head 7 and is formed with a semicircular inner profile 20, and has an open forward end 21 and an open rearward end 22. Figure 1 also illustrates, a first water spray 23 emerging from the nozzle 18 and impinging upon the inner profile 20 of the deflector 19, so that the deflector 19 shapes the first water spray 23 into a second water spray 24 of horseshoe shape, and diverging from the deflector 19, as illustrted in Figure 4, with the spray 24 projected towards and along the so-called incendive sparking area 25, which is located rearwardly of the tip 3.

In the embodiment of Figure 5, a deflector 1 9A having a rectangular inner profile 20A is provided, which profile produces the wedgeshaped spray configuration illustrated in Figure 6, the wedge diverging from the deflector 19A, and the latter being open at both its forward and rearward ends.

In the embodiment of Figure 7, a deflector 1 9B having a circular inner profile 20B is provided, which profile produces the conical spray configuration illustrated in Figure 8, the cone diverging from the deflector 19B, and the latter being open at both its forward and rearward ends.

Claims (21)

1. A mineral cutter pick comprising a head having a hard material cutter tip, and a shank extending from the head, by which shank the pick is releasably securable in an aperture, of cross-section corresponding to that of the shank, of a pick box or holder, the pick being provided with a water supply bore having a water discharge end, and a deflector carried by the pick and being so formed and located as, in use, to deflect water emerging from the discharge end towards the so-called incendive sparking area, in a predetermined water spray configuration.

2. A pick as claimed in Claim 1, wherein the deflector, or at least its inner profile, is semi-circular, or generally so, to produce a horse-shoe shaped spray.

3. A pick as claimed in Claim 1, wherein the deflector, or at least its inner profile, is rectangular, to produce a wedge-shaped spray.

4. A pick as claimed in Claim 1, wherein the deflector, or at least its inner profile, is circular, to produce a conical spray.

5. A pick as claimed in any one of Claims 2 to 4 wherein the spray is hollow.

6. A pick as claimed in any one of Claims 2 to 4, wherein the spray is "solid".

7. A pick as claimed in any preceding Claim, wherein the deflector is metallic and is attached to the pick by welding.

8. A pick as claimed in any one of Claims 1 to 6, wherein the deflector is of synthetic plastics material and is attached to the pick by screwing into a suitably tapped hole, or as a push-fit, or as a knock-in fit.

9. A pick as claimed in any preceding Claim, wherein the deflector is positioned so as to be located wholly externally of the pick.

10. A pick as claimed in any one of Claims 1 to 8, wherein the deflector is positioned so as to be located wholly internally of the pick.

11. A pick as claimed in any one of Claims 1 to 8, wherein the deflector is positioned so as to be located partially internally and partially externally of the pick.

12. A pick as claimed in Claims 9 or Claim 11, when appendant to any one of Claims 1 to 4, wherein the deflector is produced intially as a projection, as part of the pick forging, with the projection subsequently machined to produce a water deflecting surface of profile to provide the desired water spray configuration.

13. A pick as claimed in any preceding Claim, wherein the deflector is positioned opposite the discharge end of the water supply bore.

14. A pick as claimed in any preceding Claim, wherein the discharge end of the water supply bore emerges at the pick head, in a rearward face of the head, having regard to the direction of movement of the pick in use.

15. A pick as claimed in any one of Claims 1 to 13, wherein the discharge end of the water supply bore emerges at a so-called heel of a radial type pick.

16. A pick as claimed in any one of Claims 1 to 13, wherein a first discharge end of a water supply bore emerges at the head of the pick, for association with a first deflector, and a second discharge end of a water supply bore emerges at a heel of the pick, for association with a second deflector.

17. A pick as claimed in Claim 9 or 11, or any Claim appendant thereto, wherein the deflector has open forward and rearward ends.

18. A pick as claimed in Claim 2 and any Claim appendant thereto, wherein the deflector is produced from a short length of steel tube, with the short length cut axially in two, to produce two semi-circular deflectors.

19. A mineral cutter pick substantially as hereinbefore described with reference to Figures 1 to 4 of the accompanying drawings.

20. A mineral cutter pick substantially as hereinbefore described with reference to Figures 5 and 6 of the accompanying drawings.

21. A mienral cutter pick substantially as hereinbefore described with reference to Figures 7 and 8 of the accompanying drawings.