GB2166778A - Mining machines having rotary cutter heads - Google Patents

Abstract

A number of hydraulic control valves (19) are mounted on a rotary cutter drum (2) of a mining machine (1). Each control valve has an activating plunger (22) which is urged to activate the associated valve by contact with a formation (25) defining a cam profile. The formation is provided on a cut-mineral loading member (13) which is swung about the cutter head at the end of each machine traverse. The arrangement ensures that fluid jets are directed only from the cutting side of the cutter head. <IMAGE>

Description

SPECIFICATION Mining machines having rotary cutter heads This invention relates to mining machines having rotary cutter heads provided with outlet nozzle means for directing fluid towards material won by the cutter heads and having fluid supply systems for feeding fluid to the nozzle means.

In particular, although not exclusively, the invention relates to a water supply system for a rotary cutter head which has cutter tools arranged around its circumference and which, in use, at any particular instant, can have only a portion of its circumference associated with the cutting zone and in engagement with the rock or mineral face. With such a rotary cutter head in order to try and reduce the total quantity of water discharged from the outlet nozzles it is known to provide water phasing arrangements on the cutter head so that only those outlet nozzles associated with the cutting zone are fed with water. Two forms of water phasing arrangements have been proposed.

One water phasing arrangement involved providing a fixed shaft extending through the rotary drive shaft for the rotary cutter head, a water phasing distributor being fixedly mounted on the fixed shaft. Unfortunately such an arrangement encountered problems due to an efficient seal being required between the fixed and the rotating components.

In use, such seals were found to have relatively short operational lives and tended to require time consuming replacement operations.

Moreover, such seals tended not to be suitable for relatively high water pressures where water jets from the outlet nozzles were required to cut rock or mineral or to assist the cutter tools in cutting rock or mineral.

The second proposed water phasing arrangement required the cutting force on each cutter tool to urge the cutter tool against a resilient bias and, thereby, open a water feed valve. Unfortunately, no such arrangement appears to have worked successfully over a relatively long period. Consequently, the second mentioned arrangement tends not to have been widely exploited. A further anticipated disadvantage of the latter arrangement is that with relatively high water pressure systems, the cutting force exerted on the cutter tool may be insufficient to urge open the water feed valve.

An object of the present invention is to provide an improved water supply system for a rotary cutter head which enables water phasing to be achieved and which tends to overcome or reduce the above mentioned problems.

According to one aspect of the present invention, a mining machine comprises a body, a rotary cutter head mountable on the machine body or on an arm extending from the machine body, a pressurised fluid supply, fluid discharge nozzle means mounted on the cutter head, a number of hydraulic control valves mounted on the rotary cutter head for controlling the supply of pressure fluid to the discharge nozzle means, each control valve having an activating member reciprocal movement of which operates the control valve between 'open' and 'closed' operational modes, a formation rotatably mounted on the machine body or on said arm extending from the machine body such that in use, the formation can be arranged on one or other sides of the cutter head, the formation being adapted to cause control valve activating movement of the member, when in use, the cutter head rotates.

According to a second aspect of the present invention, a mining machine comprises a body, a rotary cutter head mountable on the machine body or on an arm extending from the machine body, a pressurised fluid supply, fluid discharge nozzle means mounted on the cutter head, a number of hydraulic control valves mounted on the rotary cutter head for controlling the supply of pressure fluid to the discharge nozzle means, each control valve having an activating member reciprocal movement of which operates the control valve between 'open' and 'closed' operational modes, a cut mineral loading member including a cut mineral guide arrangeable, in use, adjacent to the currently non-cutting side of the rotating cutter head, the loading member further including a support for the cut mineral guide, the support having a component rotatably mounted on the machine body or on said arm extending from the machine body such that, in use, the guide can be swung from one side of the cutter head to the other side of the cutter head to permit bi-directional operation of the cutter head, and a formation mounted on the loading member support, the formation being adapted to cause control valve activating movement of the member when in use the cutter head rotates.

Conveniently, the formation is adapted to cause the control valve activating movement of the members in one direction only, each control valve feeding pressure fluid to the associated discharge nozzle means during a portion of each rotation of the cutter head.

Advantageously, return movement of each member is under the action of fluid pressure or resilient means.

Advantageously, each control valve comprises a spool component and a seat component, the associated member being drivably attached to one of the components.

Preferably, the formation defines a cam profile, the member following the cam profile.

By way of example, one embodiment of the present invention will be described with refer ence to the accompanying drawings, in which: Figure 1 is an incomplete cross-sectional plan of a portion of a mining machine constructed in accordance with the present invention and shown in an operational position; Figure 2 is an incomplete side elevation of Figure 1; and Figure 3 is an incomplete end view of detail of Figures 1 and 2.

Figures 1 and 2 show a portion of a longwall, shearer type, mining machine having a body 1 (only a small portion of which is shown in Figure 1) and a rotary cutter head 2 mounted on an arm 3 extending from the machine body 1. A drive motor (not shown) housed within the body drives gearing extending along the arm 3 to drive epicyclic gearing housed in a gearbox 4 mounted on a drive shaft 5 extending from the arm 3 which, in turn, rotates the cutter head. In other embodiments, the cutter head is mounted directly on the machine body.

The rotary cutter head comprises a hub 6 located on the gearbox 4, a barrel component 7 supported around the hub by means of annular plates 8, and cut mineral loading vanes 9 extending around the circumference of the barrel. Cutter tools 10 (only some of which are shown) are provided in holders 11 mounted on the loading vanes 9 and an annular back plate 12.

A cut mineral loading member 13 is provided to assist loading of cut mineral from the region around the cutter head on to a conveyor (not shown) extending along the longwall face. The loading member 13 comprises a cut mineral guide 14 arranged adjacent to the currently non-cutting or trailing side of the cutter head and a support 15 for the cut mineral guide, the support having an annular component 16 rotatably mounted on a bearing housing provided on the arm 3 such that, in use, the guide can be swung from one side of the cutter head to the other side of the cutter head to permit bidirectional operation of the cutter head. Thus, as the machine traverses to and fro along the longwall face the cutter head wins mineral from the working face in both directions of transverse.Upon reaching one end of a traverse along the longwall face the cut mineral loading member is swung from one side of the cutter head to the other so that when the machine begins its next traverse in the opposite direction the loading member is adjacent the currently noncutting or trailing side of the cutter head.

The mining machine further comprises fluid discharge nozzle means including banks of nozzles 17 mounted on the cutter head adjacent to the cutter tools. Each bank of nozzles is fed with pressure fluid along a feed line 18 from one of a plurality of control valves 19 mounted on the rotary cutter head. The control valves are located between the barrel and hub component of the rotary cutter head and are angularly spaced around the head as seen in Figure 2. Also as shown in Figure 2 each control valve controls the feed of pressure fluid to a bank of nozzles mounted on a portion of the cutter head. Each control valve 19 comprises a valve housing 20 providing a valve seating and a reciprocal spool 22 which is drivably attached to a member constituted by a plunger 22 reciprocally mounted in a support bush 23.Reciprocation of the plunger 22 operates the control valve 19 between an 'open' operational mode in which pressure fluid is fed to the associated bank of nozzles and a 'closed' operational mode in which the supply of pressure fluid to the bank of nozzles is cut off.

Figure 3 shows the end of the plunger remote from the control valve to comprise a roller 24 (or a slipper cam follower) which engages a formation defining a cam profile 26, the roller moving along the formation in the direction indicated by arrow x. As seen in Figure 3 the defined cam profile has a portion of relatively low profile 27 and a portion of relatively high profile 28. Figure 2 shows the formation 25 to extend around the support for the loading member and Figure 1 indicates the portion 28 of the information on the part of the support adjacent to the trailing side of the cutter head.

Figure 1 shows pressurised fluid, typically water, is fed to each control valve via a feed pipe 30 from a distributor 31 mounted on the end of the drive shaft. Pressurised water is fed to the distributor via a tube 32 extending along a bore provided in the drive shaft and a receiving adaptor 33 mounted on the arm 3.

A hose 34 (only asmall part of which is shown) feeds pressure fluid from the water mains (not shown) or from a pump (not shown) mounted on the machine.

In operation, the machine traverses along the longwall face with the cutter head 2 rotating in the direction indicated by arrow Y and winning mineral from the working face 35, the won mineral being loaded on to the conveyor under the joint scrolling action of the loading vanes and the cut mineral loading member.

As the cutter head rotates the cam followers on the plungers of the control valves are run around the formation as indicated in Figure 3. Upon each follower starting to ascend the increasingly high portion 38 of the formation, the associated plunger is urged away from the mining machine such that the associated spool is urged into its valve housing 20 thereby opening the control valve and causing pres sure fluid to be fed to the associated bank of nozzles which direct jets towards the working mineral face. The jets are of sufficiently high pressure (eg 2,500 psi or more) to assist the cutter tools in winning mineral from the working face. It will be appreciated that as each cam follower on the plunger reaches the bottom of the portion 28 substantially as the as sociated bank of nozzles are approaching the working face.The angular extent of the relatively high profile that opens the control valves is such as to allow the opening of the valves over the portion of the cutter drum currently in engagement with the mineral being won.

Upon reaching the end of the relatively high portion the spool is permitted to move out ot its valve housing thereby closing the valve and cutting off the supply of pressurised fluid to the associated bank of nozzles.

While the cam follower is travelling along the low profile portion 27 of the formation little or no fluid is discharged from the associated nozzles which now are in the non-cutting portion of the cutter head in the vicinity of the loading member guide. By the time the roller re-engages the inclined portion of the cam profile the associated bank of nozzles once again is approaching the cutting or leading side of the cutter head and pressurised fluid again is fed to the discharge nozzles.

Upon the machine reaching the end of its traverse along the longwall face, the loading member is swung about its mounting to be re-located on the opposite side of the cutter head, now the non-cutting side. As the loading member is swung through approximately 180 , the formation on the loading member support is also swung to its diametrically opposed side. Thus, the increasingly high portion 28 of the formation now lies on the opposite side of the cutter head such that the discharge nozzles on the new cutting side of the cutter head are fed with pressurised fluid via the control valves.

Thus, it will be appreciated that the present invention provide a single and reliable means for changing the side of the rotary cutter head fed with high pressure fluid. The invention ensures that only those nozzles directed towards the working face are activated. As the nozzles on the currently non-cutting side of the cutter head are not fed with high pressure fluid, potentially dangerous high pressure jets are not directed towards workmen situated on the longwall face. The invention enables the machine to operate bi-directional working with high pressure jets associated with the currently cutting side of the cutter head irrespective of the direction of machine traverse.

In other embodiments of the invention the discharge nozzles for the jets are mounted in the cutter tool. In still other embodiments of the invention the mineral is won by the high pressure jets; the cutter tools being dispensed with altogether or have only a substantially minor role in the mineral winning operation.

In other embodiments of the present invention the formation for reciprocating the plungers is not mounted on the loading members support. For example, the formation may be mounted on an annular collar carried by a bearing housing supporting the cutter head drive shaft. Alternatively, the formation may comprise two cam components associated with opposite sides of the cutter head, respectively, the two cam components being reciprocated to and fro into or our of control valve activating positions.

In other embodiments of the invention, the relatively low profile portion 27 is dispensed with, outward movement of the plunger being limited by abutment means provided on the valve or on the rotary cutter head.

In other installations the water discharged into the cutting zone is of relative low pressure and is used to suppress dust generated during cutting and/or to cool the cutter tools.

Claims (7)

1. A mining machine comprising a body, a rotary cutter head mountable on the machine body or on an arm extending from the machine body, a pressurised fluid supply, fluid discharge nozzle means mounted on the cutter head, a number of hydraulic control valves mounted on the rotary cutter head for controlling the supply of pressurised fluid to the discharge nozzle means, each control valve having an activating member reciprocal movement of which operates the control valve between 'open' and 'closed' operational modes, a formation rotatably mounted on the machine body or on said arm extending from the machine body such that in use, the formation can be arranged on one or other sides of the cutter head, the formation being adapted to cause control valve activating movement of the members when, in use, the cutter head rotates.

2. A mining machine comprising a body, a rotary cutter head mountable on the machine body or on an arm extending from the machine body, a pressurised fluid supply, fluid discharge nozzle means mounted on the cutter head, a number of hydraulic control valves mounted on the rotary cutter head for controlling the supply of pressure fluid to the discharge nozzle means, each control valve having an activating member reciprocal movement of which operates the control valve between 'open' and 'closed' operational modes, a cut mineral loading member including a cut mineral guide arrangeable, in use, adjacent to the currently non-cutting side of the rotating cutter head, the loading member further including a support for the cut mineral guide, the support having a component rotatably mounted on the machine body or on said arm extending from the machine body such that, in use, the guide can be swung from one side of the cutter head to the other side of the cutter head to permit bidirectional operation of the cutter head, and a formation mounted on the loading member support, the formation being adapted to cause control valve activating movement of the members when, in use, the cutter head rotates.

3. A mining machine as claimed in claim 2, in which the formation is adapted to cause control valve activating movement of the members in one direction only, each control valve feeding pressure fluid to the associated discharge nozzle means during a portion of each rotation of the cutter head.

4. A mining machine as claimed in claim 2 or 3, in which each control valve comprises a spool component and a seat component, the associated member being drivably attached to one of the components.

5. A mining machine as claimed in any one preceding claims, in which the formation defines a cam profile, the member following the cam profile.

6. A mining machine as claimed in claim 5, in which a cam follower or roller or slipper is provided on each member.

7. A mining machine substantially as described herein and substantially as shown in the accompanying drawings.