GB2045839A - Boxes for mounting mineral mining picks - Google Patents

Abstract

A pick box 1 for securing to the cutting implement of a mining machine comprises a base component 3 to be secured to the cutting implement and a wear component 4 to be releasably secured to the base component 3, the latter having a recess 7 with an open mouth 8 and the wear component 4 having a spigot 13 releasably fitting into the recess 7 and also having a socket for receiving a shank of a mineral mining pick, the recess 7 and the spigot 13 having at least portions of their respective internal and external surfaces defining a non-binding taper extending substantially the entire length of both the recess 7 and the spigot 13 from a larger cross-sectional area adjacent the mouth 8 of the recess 7 to a smaller cross-sectional area remote from the mouth 8, and means 12 for releasably securing the wear component 4, to the base component 3. <IMAGE>

Description

SPECIFICATION Boxes for mounting mineral mining picks This invention relates to boxes for mounting mineral mining picks in mining machines.

Such boxes are usually permanently secured, as by welding, to a rotary drum, head or helical vane, or to a cutter chain, (all referred to hereinafter as a cutting implement) and are formed with sockets for the reception of shanks of the picks, with latching means for releasably securing the shanks in the sockets.

In use, the boxes become worn because of abrasion by the mineral being mined and the pressure with which the picks bear on the boxes under severe working conditions, as a result of which a worn box has to be removed by burning-off and replaced by a fresh box by welding. Such operations cannot be undertaken in a coal mine for instance due to the release of methane, and there results a considerable loss of operational time whilst the cutting implement is removed from the mining machine, brought to a surface workshop, a box or boxes burned off, a fresh box or boxes welded on, and the cutting implement returned to and refitted on the mining machine.

According to the present invention, a pick box for securing to the cutting implement of a mining machine comprises a base component adapted to be secured to a cutting implement and a wear component adapted to be releasably secured to the base component, the base component having a recess with an open mouth and the wear component having a spigot releasably fitting into the recess and also having a socket for receiving a shank of a mineral mining pick, the recess and the spigot having at least portions of their respective internal and external surfaces defining a non-binding taper extending substantially the entire length of both the recess and the spigot from a larger cross-sectional area adjacent the mouth of the recess, to a smaller cross-sectional area remote from the mouth, and means for releasably securing the wear component to the base component.

Just as a worn or damaged pick can be readily removed from the wear component and a fresh pick inserted, so a worn or damaged wear component can be readily removed from the base component and a fresh wear component inserted, without having to remove the cutting implement from the machine because the base component is wholly or substantially protected from wear by the wear component. Thus, while picks may have to be replaced daily, it is probable that wear components may not need replacing more frequently than monthly, or under very severe working conditions, no more frequently than weekly, and that base components may not need replacing more than yearly, when it is probable that the cutting implement and/or the machine will need to be brought to a surface workshop for overhaul.

A non-binding taper is generally above 7" included angle, but it is preferably at least 10 , so that the surface finish in the recess and on the spigot need not be of particularly high standard. However, it is preferred to interpose a non-ferrous sleeve or shim e.g., a sleeve of copper or copper alloy, synthetic plastics e.g. nylon, rubber, between the recess and the spigot, to reduce any tendency towards binding between the components, yet assisting in firm bedding of the spigot in the recess. The sleeve or shim may be a separate element e.g. when of copper, or may be bonded to the spigot e.g. when of rubber.

The wear component may be provided with a flange adapted to overlie an adjacent surface of the base component, firstly to give enhanced protection of the base component from wear and secondly, with the flange clear of the adjacent surface of the base component, to define a gap for the insertion of a wedge or other device for removing a wear component from a base component.

The recess and the spigot may have mating frusto-conical surfaces, with a non-binding taper, which is suitable if the socket in the wear component is of circular cross-section, whether tapered or cylindrical, for receiving tapered round or cylindrical pick shanks, respectively.

Alternatively, the recess and the spigot may have cross-sections with at least two opposite pairs of mating surfaces defining the non-binding taper, which is suited to the incorporation in the wear component of a socket with a rectangular or square cross-section. Thus, the recess and the spigot may each have two planar, parallel side surfaces, or two planar converging side surfaces, in combination with two converging, radiussed (part cylindrical or part conical) end surfaces, or two converging planar end surfaces. The inter-sections between the side surfaces and the end surfaces may be radiussed or bevelled.

It will be appreciated that wear and base components with mating frusto-conical surfaces may be manufactured by turning and boring workpieces of circular cross-section (e.g. cylindrical).

Wear and base components with planar sided recesses and spigots on the other hand, may be manufactured by forging followed by finish machining. In this case, the outside of the base component preferably has a rectangular cross-section, preferably non-tapering, and the flange of the wear component preferably having a peripheral shape corresponding to the external cross-section of the base component.

As a means of releasably securing the wear component to the base component, the latter may incorporate an internal shoulder remote from the mouth of the recess, against which shoulder may bear a resilient ring housed in a groove adjacent the end of the spigot remote from the flange. Alternatively, the base component may be provided with one hole or a pair of holes aligned with a groove or a pair of grooves adjacent the end of the spigot to receive a pin, screw, or staple.

The wear component may be provided with any of the known forms of latching means for releasably securing the shanks of picks, or the wear component may be provided with a recess intersecting the socket or an enlargement thereof, for receiving latching means or a resilient ring on the shank of a pick.

The base component and the wear component may be formed of the same steel quality, and may be case hardened to the same extent.

The invention will now be described in greater detail, by way of examples, with reference to the accompanying drawings, in which: Figure 1 is a plan view of a first embodiment of pick box in accordance with the present invention; Figure 2 is a section on the line ll-ll of Figure 1; Figure 3 is a section on the line Ill-Ill of Figure 1; Figure 4 is a plan view of a second embodiment of pick box in accordance with the present invention; Figure 5 is a section on th line V-V of Figure 4, Figure 6 is a section on the line VI-VI of Figure 4; Figure 7 shows pick boxes of the embodiment of Figures 4to 6 mounted in a cutting element; Figure 8 is a side elevation, partly in section, of the base component of a third embodiment of pick box in accordance with the present invention;; Figure 9 is a plan view of Figure 8; Figure 10 is an end elevation of Figure 8; Figure 11 is a side elevation of the wear component of the third embodiment of pick box in accordance with the present invention; Figure 12 is a plan view of Figure 11; Figure 13 is a section on the line XIII-XIII of Figure 12,and Figure 14 is a side view, partly in section, of the wear component of a fourth embodiment of pick box in accordance with the present invention.

In the embodiment of Figures 1 to 3, a pick box 1, for securing indirectly to a mineral mining machine (not shown) and serving to mount a mineral mining pick (not shown) on a cutting implement 2 (Figure 7) carried by the machine, is a two-part construction comprising a base component 3 and a wear component 4. The base component 3 is adapted to be secured to the cutting implement 2 by welding. Thus a notch 5 of appropriate dimensions is cut in a helical vane 6 of the cutting implement 2, the latter being in the form of a spiral vane cutting drum, such drums being used extensively in coal mining operations.

The base component 3 has a recess 7 with an open mouth 8 and an upper surface 9 adjacent the mouth 8. Also in the embodiment of Figures 1 to 3, the recess 7 is defined by one pair of opposite, arcuate surfaces 10 and another pair of opposite, planar surfaces 11, each pair of surfaces 10,11, having a non-binding taper extending substantially the entire length of the recess 7, while a shoulder 12 is provided towards the lower end of the base compo nent3.

The wear component 4 is adapted to engage releasably, the base component 3. Thus the wear component 4 comprises a spigot 13 with a pair of opposite, arcuate surfaces 14 and a pair of opposite, planar surfaces 15, the surfaces 14 and 15 also having a non-binding taper corresponding to that of the surfaces 10 and 11 and extending substantially the entire length of the spigot 13, but interposed between these surfaces is a copper sleeve 16. The wear component 4 is provided at an outer end with a flange 17 which overlies the surface 9 of the base component 3, as can be appreciated from Figure 1, firstly to protect the base component 3 from wear and secondly to leave a gap 18 into which a wedge (not shown) is insertable when it is desired to remove the wear component 4 from the base component 3.At an end of the spigot 13 remote from the flange 17, the wear component 4 is provided with a peripheral groove 19 in which is located a resilient ring 20 adapted to bear against the shoulder 12 and serving as a means for releasably securing the wear component 4 to the base component 3. As can be seen from Figure 1, the wear component 4 is provided with a socket 21 of conventionai crosssection, to receive the shank, of corresponding cross-section, of a mineral mining pick (not shown).

In the second embodiment shown in Figures 4 to 7, components that are of modified construction compared with the first embodiment have the suffix A on the reference numerals of the first embodiment. The second embodiment differs from that of Figures 1 to 3 in that firstly the flange on the wear component 4A is absent, secondly opposite surfaces 1 OA are planar, rather than arcuate, and thirdly a different means is employed for releasably securing the wear component 4A to the base component 3A.

Thus the means comprises a pair of spaced apart holes 22 drilled through the base component 3A and intersecting the surface 11 of the recess 7. The spigot 13A is provided in each surface 15A with two blind recesses 23 in each of which is secured a latching member 24 of synthetic plastics material having a plurality of fingers 25 projecting beyond the surface 15 to engage, as indicated in Figure 6, shoulders 12A defined by portions of the holds 22.

In the third embodiment shown in Figures 8 to 13, modified components are given the suffix B. The third embodiment differs from that of the first and second embodiments in that firstly this third embodiment is intended to receive a mineral mining pick having a circular section shank and hence the socket 21 B in the wear component 4B is of suitable circular cross-section, and secondly is intended to receive a wear component 4B having a circular section spigot 13B, and hence the recess 7B in the base component 3 is of a corresponding, frusto-conical cross-section.

The wear component 4B is provided with a flange 17B having a flat 26 for location purposes. It will also be observed from Figure 8 that the base component 3B incorporates inclined surfaces 27 and hence if the base component of this embodiment were to be located in a vane 6 of a spiral vane cutting head, then the notch 5 would need to be appropriately shaped.

In the fourth embodiment, shown in Figure 14, modified components are given the suffix C. The base component 3C has a frusto-conical outer periphery 28 for accurate location in a prepared recess 29 in a cutting implement 2C. The latter takes the form of a rotary cutting head, e.g. of a roadway driving machine, provided with a plurality of recesses 29 produced by taper drilling at peripheral locations where mining picks are required. After insertion of the base member 3C in its recess 29, securing is effected by welding at 30. It will be observed that internally, the base component 3C is identical to the base component 3B and hence will accept a wear component 4B.

Claims (24)

1. A pick box for securing to the cutting implement of a mining machine comprising a base component adapted to be secured to a cutting implement and a wear component adapted to be releasably secured to the base component, the base component having a recess with an open mouth and the wear component having a spigot releasably fitting into the recess and also having a socket for receiving a shank of a mineral mining pick, the recess and the spigot having at least portions of their respective internal and external surfaces defining a non-binding taper extending substantially the entire length of both the recess and the spigot from a larger cross-sectional area adjacent the mouth of the recess, to a smaller cross-sectional area remote from the mouth, and means for releasably securing the wear component to the base component.

2. A pick box as claimed in Claim 1, wherein the n :3n-binding taper is at least 10 included angle.

3. A pick box as claimed in Claim 1 or Claim 2, wherein a non-ferrous sleeve or shi-m is interposed between the wear component and the base compo nent

4. A pick box as claimed in Claim 3, wherein the sleeve or shim is of copper or copper alloy.

5. A pick box as claimed in Claim 3, wherein the sleeve or shim is of synthetic plastics.

6. A pick box as claimed in Claim 5, wherein the synthetic plastics is nylon.

7. A pick box as claimed in Claim 3, wherein the sleeve or shim is of rubber.

8. A pick box as claimed in any one of Claims 4 to 6, wherein the sleeve or shim is a separate eiement.

9. A pick box as claimed in Claim 7, wherein the rubber sleeve or shim is bonded to the spigot of the wear component.

10. A pick box as claimed in any one of Claims 1 to 9, wherein the wear component is provided with a flange adapted to overlie an adjacent surface of the base component.

11. A pick box as claimed in Claim 10, wherein the flange is clear of the adjacent surface of the base component to define a gap.

12. A pick box as claimed in any one of Claims 1 to 11, wherein the recess and the spigot have mating frusto-conical surfaces, with a non-binding taper.

13. A pick box as claimed in any one of Claims 1 to 11, wherein the recess and the spigot have cross-sections with at least two opposite pairs of mating surfaces defining the non-binding taper.

14. A pick box as claimed in Claim 13, wherein the recess and the spigot each have two planar, parallel side surfaces.

15. A pick box as claimed in Claim 13, wherein the recess and the spigot each have two planar converging side surfaces, in combination with two converging, radiussed (part cylindrical or part conical) end surfaces, or two converging planar end surfaces.

16. A pick box as claimed in Claim 14 or Claim 15, wherein the intersections between the side surfaces and the end surfaces are radiussed or bevelled.

17. A pick box as claimed in Claim 14or Claim 15, wherein the outside of the base component has a non-tapering, rectangular cross-section, and the flange of the wear component has a peripheral shape corresponding to the external cross-section of the base component.

18. A pick box as claimed in any preceding Claim, wherein as a means of releasably securing the wear component to the base component, the latter incorporates an internal shoulder remote from the mouth of the recess.

19. A pick box as claimed in Claim 17, wherein a resilient ring housed in a groove adjacent the end of the spigot bears against the shoulder.

20. A pick box as claimed in any one of Claims 1 to 16, wherein the base component is provided with one hole or a pair of holes aligned with a groove or a pair of grooves adjacent the end of the spigot to receive a pin, screw, or staple.

21. A pick box for securing to the cutting implement of a mining machine substantially as hereinbefore described with reference to Figures 1 to 4 of the accompanying drawings.

22. A pick box for securing to the cutting implement of a mining machine substantially as hereinbefore described with reference to Figures 5 to 7 of the accompanying drawings.

23. A pick box for securing to the cutting implement of a mining machine substantially as hereinbefore described with reference to Figures 8 to 13 of the accompanying drawings.

24. A pick box for securing to the cutting implement of a mining machine substantially as hereinbefore described with reference to Figure 14 of the accompanying drawings.