ZA201002197B

ZA201002197B - Pick sleeve

Info

Publication number: ZA201002197B
Application number: ZA2010/02197A
Authority: ZA
Inventors: Clyde Royden Marais
Original assignee: Clyde Royden Marais
Priority date: 2009-04-14
Filing date: 2010-03-29
Publication date: 2010-11-24

Description

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THIS INVENTION relates to a pick sleeve and a pick sleeve extraction tool. The invention also relates to a method of extracting a pick sleeve from a continuous miner cutter drum, the pick sleeve extraction tool employed in the method of extracting the pick sleeve, and a pick sleeve extraction kit.

Picks of the kind in question are cutting picks used for breaking up coal or rock, for example at a face of a coal mine. The picks have a chiselled point at one end and a blunt end, the blunt end operable to be fitted to a coal cutter drum of a continuous miner. Pick sleeves of the kind refer to attachment means whereby the other end of the pick is fitted to the coal cutter drum via the sleeve box.

BACKGROUND OF THE INVENTION

A continuous coal mining machine (or continuous miner) includes a cutter drum having a generally cylindrical body with radically extending start vanes from which a plurality of picks jut out at regular intervals and at fixed angles from the vanes. During operation of the continuous miner, the drum rotates and the picks follow a defined cutting path subject to the rotational route of the drum. Drive means of the miner rotate the drum, and the picks engage with a working rock face of a coal mine In order to break up coal at the rock face. .

A pick is attached to the cutter drum via a so-called pick sleeve, the pick sleeve including one end operable to receive and locate the blunt end of a pick and another end operable to be located in a sleeve box (or support block), the sleeve box being integrally mounted circumferentially on the drum. In use, the blunt end of the pick is located in the one end of the pick sleeve and the other end of the pick sleeve located in the sleeve box of the cutter drum.

Maintenance of the continuous miner requires that the pick sleeve be removed and replaced due to operational wear of the sleeve. Existing methods of removing the sleeve, for example by forced removal with a 16 pound hammer, pose difficulties, amongst them the inability to dislodge the sleeve as a result of burring of the sleeve. In order to dislodge the burred sleeve, the miner must be shut down and gas cutters and welding equipment used to remove the sleeve, resulting in downtime of the mining machine. To avoid downtime, operators fail to replace the damaged sleeve, which results in extensive damage to the sleeve box. The current invention aims to mitigate the abovementioned problems by providing an improved sleeve and sleeve extraction tool.

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SUMMARY OF THE INVENTION

According to a first aspect of the invention, there is provided a generally elongate pick sleeve which includes: a cylindrical shank at one end of the sleeve, the shank including a shank wall of which at least part of an outer circumference of the shank wall is dimensioned to be operably located in a sleeve box of a cutter drum by seating the cylindrical shank on a rim of the sleeve box; a frustum connected to the shank at an opposed end of the sleeve and centered about the shank axis for operatively receiving a pick; a bore extending substantially axially through the cylindrical shank and frustum of the sleeve; the cylindrical shank wall having a thickness equal to or greater than 8.5mm at the one end of the sleeve.

The pick sleeve may be precision machined, ideally from forged steel.

The pick sleeve may be induction hardened prior to being precision machined.

According to another aspect of the invention there is provided a pick extraction tool, the tool including: a punchable cylindrical shaft having an outer diameter equal to or greater than an outer diameter of a shank wall of a pick sleeve as hereinbefore described a recess at one end of the shaft operable to receive and locate in use an end of an elongate alignment pin, another end of the alignment pin operable to be temporarily located in a bore of the cylindrical shank of the pick sleeve as hereinbefore described;

Thus, in use and during extraction of a pick sleeve from a pick box, the one end of the cylindrical alignment pin may be located in the recess of the shaft whilst the other end Is located in the bore of the cylindrical shank of the sleeve, thereby bringing the sleeve in alignment with the punchable shaft in readiness for the punch to centrally strike the shank of the sleeve when struck by a hammer at the end furthest from the sleeve and upon removal of the sleeve from a pick box of a cutter drum of a continuous miner.

The pick extraction tool may include the elongate alignment pin.

Preferably, the elongate alignment pin is a cylindrical alignment pin.

The punchable cylindrical shaft may include a slot at the recess and transverse to the shaft for receiving a securing pin for operatively securing the one end of the alignment pin in

® 4 position, i.e. within the recess. To this end, the alignment pin may include a cross-sectional hole through which the securing pin may be inserted. In one embodiment of the invention, the securing pin is spring-loaded such that, in use, the securing pin is held tightly in place in the recess of the punchable cylindrical shaft.

The pick extraction tool may include a strikeable disc having a centre-hole for operative locating of the disc about the alignment pin and seating on the recessed end of the punchable cylindrical shaft. The disc may be of a softer material than that of the sleeve shank, for example of brass, to avoid damage to the sleeve when punched by the shaft, particularly burring of the sleeve shank when extracted from the sleeve box of the cutter drum of the continuous miner.

The strikeable disc may have an outer diameter corresponding to or being greater than the outer diameter of the shank wall of the pick sleeve. In one embodiment, the strikeable disc may include a raised inner portion whose diameter corresponds to an inner diameter of the shank wall of the pick sleeve, thereby providing a flange of the disc whereon the shank wall of the sleeve may be seated.

In use, the alignment pin ensures that the punchable shaft, strikeable disc and shank wall of the sleeve are concentrically aligned so that the sleeve may be centrally struck when punched.

The pick extraction tool may include a handle attached to the punchable cylindrical shaft. One end of the handle may be pivotally attached to the shaft so that the handle 1s generally transverse to the shaft and allows for relative movement of the handle with respect to the shaft.

The end of the handle may be attached to the shaft by a locking pin operable to pivotally secure the handle to the shaft.

The handle may be of a shock-absorbing material so as to reduce shock to a user holding the handle when the shaft is being punched. The handle may include a gripping surface.

The punchable cylindrical shaft may include a further recess at another end (the end furthest from the sleeve shank when in use), the further recess operable to receive a strike head of material softer than that of the cylindrical shaft, such as brass, to prevent damage to the shaft when punched with a hand tool such as a hammer. The other end of the shaft may include a cross-sectional slot operable to receive and locate a slotted spring pin for securing the strike head.

According to another aspect of the invention there is provided a method of manufacturing a pick sleeve as hereinbefore described, the method including:

® > precision machining a pick sleeve with a cylindrical shank of a thickness equal to or greater than 8.5mm at the one end of the sleeve; and prior to machining of the pick sleeve, induction hardening the sleeve.

In accordance with yet another aspect of the invention there is provided a method of extracting a pick sleeve as hereinbefore described from a cutter drum of a continuous miner, the method including: aligning a pick extraction tool as hereinbefore described with a pick sleeve as hereinbefore described and located in a pick box of the cutter drum; holding the extraction tool by its handle; locating the alignment pin of the extraction tool in the bore of the pick sieeve to bring the strikeable disc of the extraction tool in substantially flush contact with the shank wall of the pick sleeve; and striking an end of the shaft of the extraction tool with a hand tool in order to remove the sleeve from the sleeve box.

Striking of the end of the shaft may include striking the strikehead of the extraction tool.

The invention extends to a pick extraction kit which includes: a pick sleeve as hereinbefore described; and a pick extraction tool as hereinbefore described.

It should be appreciated that the pick extraction tool and the method of extracting the pick sleeve as hereinbefore described may similarly be applied to the inserting and lodging of the pick sleeve into the sleeve box of a cutter drum.

The invention will now be described by way of non-limiting example with reference to the accompanying diagrammatic drawings:

DRAWINGS

In the drawings,

Figure 1 shows a side view of a pick sleeve and a pick sleeve extraction tool according to embodiments of aspects of the invention.

Figure 2 shows a perspective view of a pick sleeve extraction tool according to one aspect of the invention.

Figure 3 shows a side view of a pick sleeve extraction tool in use and in accordance with one embodiment of the invention.

Unless otherwise indicated, like reference numerals denote like parts of the figure.

DETAILED DESCRIPTION OF THE INVENTION

In figure 1, reference numeral 10 generally indicates an embodiment of a pick sleeve and reference numeral 20 generally indicates an embodiment of a pick sleeve extraction tool according to aspects of the invention.

The pick sleeve 10 has a cylindrical shank 12, the shank 12 having a shank wall 14 at one end 15 of which the outer circumference is dimensioned to operable be located in a sleeve box of a cutter drum as will become more apparent in figure 3. The shank extends to a cone 16, the cone 16 tapering toward the end 17 of the sleeve 10 and about the axis 13 of the shank 12. A base 18 of the cone 16 faces the cylindrical shank 12, the base operable to be seated on a rim of the sleeve box (shown in figure 3). The tapered end 17 of the cone 16 is operable to receive a pick (not shown here). A bore 19 extends throughout the sleeve 10 along the axis 13.

It should be particularly noted that the cylindrical shank wall 14 has a thickness 14 1 equal to or greater than 8.5mm. Ideally, the shank wall thickness 14.1 is 8.5mm. The pick sleeve 10 is manufactured of forged steel whereafter it is induction hardened by heat treatment to reduce burring of the shank wall 14. ’

Referring to the sleeve extraction tool 20, the tool 20 comprises a punchable cylindrical shaft 22 having an outer diameter 24 equal to or greater than the outer diameter of the shank wall 14 of the pick sleeve 10. The shaft 22 has a recessed opening 24 at one end 26 of the shaft 22, the recessed opening 24 operable to receive and when in use locate an end 28 of an elongate cylindrical alignment pin 29. An end 30 of the alignment pin 29 is operable to be located in the bore 19 of the pick sleeve 10.

In use and during extraction or insertion of the pick sleeve into or out of a pick box (see figure 3), the end 28 of the alignment pin 29 is located in the recessed opening 24 of the shaft 22 whilst the other end 30 is located in the bore 19 of the cylindrical shank 12 of the sleeve 10, thereby aligning and centring the sleeve 10 with the shaft 22 about the axis 13 In order for the cylindrical shaft to be struck at an end 32 of the shaft furthest from the sleeve 10. The punch able shaft 22 is slotted at the recessed opening 24 to allow for the insertion of a securing pin 34 for operatively securing the end 28 of the alignment pin 29 in the recessed opening 24. According to this embodiment of the extraction tool 20, the securing pin 34 is spring-loaded to hold the alignment pin 29 tightly in place in the opening 24.

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The pick extraction tool 20 includes a strikeable disc 36 operatively fitting around the alignment pin 29 and seated on an end 37 of the cylindrical shaft 22. The strikeable disc 36 is of brass material to avoid damage or burring to the shank wall 14 of the sleeve when punched by the extraction tool 20. The strikeable disc 36 has an outer diameter corresponding to that of the shank wall 14. In use and when the extraction tool 20 is used to punch the sleeve 10 out of the sleeve box of the cutter drum (shown more clearly in figure 3), the alignment pin 29 ensures that the punchable shaft 22, the strikeable disc 36 and the bore 19 of the sleeve are concentrically aligned to enable the sleeve 10 to be centrally punched thereby effecting a solid blow to the sleeve 10.

The extraction tool 20 includes a handle 40, the handle 40 being pivotally attached to the shaft 22 at 42 to allow for relative movement of the handle 40 with respect to the shaft 22. An end of the handle at 42 is pivotally secured to the shaft 22 by a spring-loaded locking pin 43. The handle 40 has a gripping surface 40.1 to assist in a user's holding the handle 40, and Is manufactured of a shock-resistant material.

The punchable shaft 22 includes a further recess 44 at the end 32 of the shaft, the further recess 44 operable to receive and locate a strike head 46 of brass material. The strike head 46 protects the end 32 of the shaft 22 from damage when being used and struck by, for example, a hammer (not shown here). The strike head 46 is secured to the shaft 22 by a spring pin 47.

Referring now to figure 2 of the drawings, reference numeral 20 shows the pick extraction tool of figure 1 in perspective view for the purpose of clarity. The extraction tool 20 includes the punchable cylindrical shaft 22 having the alignment pin 29 inserted into the recessed opening 24, the alignment pin 29 secured in the opening by the securing pin 34. The strikeable disc 36 of brass material is held in place by the alignment pin 29. The tool 20 includes the handle 40 pivotally attached to the shaft 22 at 42 and pivotally secured to the shaft by the spring-loaded locking pin 43. The end 32 of the shaft 22 includes the strike head 46 of brass material and secured to the shaft 22 by the spring pin 47.

With reference to figure 3 of the drawings, numeral 50 generally denotes the pick extraction tool 20 in use. The pick sleeve 10 is lodged in a pick sleeve box 52 of a cutter drum 54 of a continuous miner. In order to remove the sleeve 10 from the sleeve box 52, the punchable cylindrical shaft 22 of the extraction tool 20 is aligned with the sleeve 10, and the alignment pin 29 of the tool 20 located in the bore of the cylindrical shank 12 such that the strikeable disc 36 Is In direct contact with the shank wall 14. Whilst holding the tool 20 by the handle 40, the shaft 22 of the tool 20 is struck by a hammer 54 on the brass strikehead 46 at the end 32 of the shaft 22,

® 8 which in turn strikes the sleeve 10 and dislodges it from the sleeve box 52 without damage to the shank wall 14 of the sleeve 10. By similar action, the tool 20 may be used to lodge the sleeve 10 in the sleeve box 52 of the cutter drum 54.

Advantageously, the pick sleeve and pick extraction tool as hereinbefore described reduces pick box and cutter drum damage and increases machine operator safety.

Claims

ng 1] — Claims: cL

1. A generally elongate pick sleeve which includes: a cylindrical shank at one end of the sleeve, the shank having a shank wall of which at least part of an outer circumference of the wall is dimensioned to be operably located in a sleeve box of a cutter drum by seating the cylindrical shank on a rim of the sleeve box and the shank wall having a thickness equal to or greater than

8.5mm at at least an end of the shank; a frustum connected to the shank at an opposed end of the sleeve and centered about the shank axis for operatively receiving a pick; a bore extending substantially axially through the cylindrical shaft and frustum of the sleeve;

2. A generally elongate pick sleeve as claimed in claim 1 that is manufactured of precision machined forged steel.

3. A generally elongate pick sleeve as claimed in claim 2 wherein the precision machined forged steel is induction hardened.

4. A pick extraction tool which includes: a punchable cylindrical shaft having an outer diameter equal to or greater than an outer diameter of a shank wall of a pick sleeve, the pick sleeve having a cylindrical shank at one end of the sleeve; a shank wall of which at least part of an outer circumference of the wall 1s dimensioned to be operably located in a sleeve box of a cutter drum by seating the cylindrical shank on a rim of the sleeve box and the shank wall having a thickness equal to or greater than 8.5mm at at least an end of the shank; a frustum connected to the shank at an opposed end of the sleeve and centered about the shank axis for operatively receiving a pick; and a bore extending substantially axially through the sleeve; a recess at one end of the shaft operable to receive and locate in use an end of an elongate alignment pin, another end of the alignment pin operable to be located in the bore of the cylindrical shank of the pick sleeve.

5. A pick extraction tool as claimed in claim 4 which includes the elongate alignment pin.

6. A pick extraction tool as claimed in claim 5 of which the punchable cylindrical shaft has a slot at the recess and transverse to the shaft for receiving a securing pin for operatively securing the alignment pin in the recess.

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7. A pick extraction tool as claimed in claim 5 or claim 6 which includes a strikeable disc for operatively locating the disc about the alignment pin and seating the disc on the one end of the shaft.

8. A pick extraction tool as claimed in claim 7, the strikeable disc being of a softer material than that of the sleeve shank to operatively prevent burring of the sleeve when being punched by the shaft to extract the pick sleeve from the cutter drum.

9. A pick extraction tool as claimed in claim 7 or claim 8 of which the strikeable disc has an outer diameter equal to or greater than the outer diameter of the shank wall of the sleeve to provide a flange whereon the shank wall of the sleeve may be operatively seated.

10. A pick extraction tool as claimed in any one of claims 5 to 9 inclusive wherein the elongate alignment pin is cylindrical.

11. A pick extraction tool as claimed in any one of claims 4 to 9 inclusive which includes a handle attached to the punchable shaft.

12. A pick extraction tool as claimed in claim 11 wherein the handle is pivotally attached to the shaft so that the handle to allow relative movement between the handle and the shaft.

13. A pick extraction tool as claimed in any one of claims 4 to 9 inclusive which includes a second recess at the other end of the shaft for operatively receiving a strike-head between a hammer and the shaft.

14. A method of extracting a pick sleeve which includes: taking a pick extraction tool as claimed in any one of claims 7 to 13 and aligning the tool with a pick sleeve as claimed in any one of claims 1 to 3; locating the alignment pin of the tool in the bore of the sleeve to bring the strikeable disc in contact with an end of the sleeve; striking the other end of the shaft of the extraction tool with a hand tool to remove the sleeve from a sleeve box of a continous cutter of a mining machine.

15. A method as claimed in claim 14 which includes temporarily inserting a strike-head between the hand tool and the shaft of the tool.

16. A pick sleeve as claimed in claim 1, substantially as herein described and illustrated.

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17. A new pick sleeve, substantially as herein described.

18. A pick extraction tool as claimed in claim 4, substantially as herein described and illustrated.

19. A new pick extraction tool, substantially as herein described.

20. A method of extracting a pick sleeve as claimed in claim 14, substantially as herein described and illustrated.

21. A new method of extracting a pick sleeve, substantially as herein described. DATED THIS 29" DAY OF MARCH 2010 NN SMIT & VAN WYK, INC. APPLICANT'S PATENT ATTORNEYS