_¾ The present application claims priority from Australian Provisional Patent Application No 2012900377 filed on 2 February 2012, the content of which is incorporated herein by reference.

The present disclosure relates to a cutting tool and a tool assembly. The cutting tool and tool assembly have been developed primarily for use in longwall coal mining machines and iron ore mining machines. However, it will be appreciated that the cutting tool and tool assembly are not limited to such applications and may also be used, for example, in other mineral winning machines, or indeed in excavation equipment, such as road headers, surface miners, continuous miners or tunnel boring machines.

Tool systems in known longwall coal mining machines are mounted on a shearer drum comprising a barrel around which extends a helical vane. The tool system is mounted on a radially outer edge of the helical vane and faceplate.

Tool systems in known iron ore mining machines are mounted directly on the cutterhead, commonly in a generally helical pattern along the length of the drum.

The tool system in known mining machines may include a spray unit for directing water toward a cutting end of the cutting tool. The spray unit is either threadedly engaged to a heel of the cutting tool or to the tool holder, or may be retained by a retaining device. A problem with known tool system however, is that it can be difficult to accurately direct water from the spray unit toward the cutting end of the tool. Another problem is that the spray unit can become clogged with particulate matter generated by the mining process. A further problem is that the spray unit can be damaged during mining operations.

Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed before the priority date of each claim of this application.

Throughout this specification the word "comprise", or variations such as

"comprises" or "comprising", will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

In a first aspect, the present disclosure provides a cutting tool for a mining machine, said cutting tool comprising: a body comprising a cutting end for winning mineral from an ore body and a mounting end comprising a shank complementary with and engageable in a socket of a tool holder to secure the cutting tool to the mining machine;

a bore in the body extending generally from the mounting end to the cutting end; and

one or more air inlet openings extending from an external surface of the body to the bore.

A plurality of the air inlet openings may be provided. In some embodiments, the air inlet openings are generally circular in transverse cross-section. In other embodiments, the air inlet openings have a transverse cross section that is substantially longer in one dimension than in a direction substantially perpendicular thereto (eg. the air inlet openings may be oval in transverse cross section). In such embodiments, the longer dimension may be oriented in a direction that extends generally from the mounting end toward the cutting end.

At least one of the air inlet openings may be provided at a rear of the cutting tool. At least one of the air inlet openings may be provided at a side of the cutting tool. In one embodiment, air inlet openings are provided at a rear of the cutting tool and on both sides of the cutting tool.

An end of the bore associated with the cutting end may terminate rearwardly of a cutting tip of the cutting tool.

A line of weakness may be provided in the body for defining a predetermined failure point of the tool. The line of weakness may be at least partially defined by one or more of the air inlet openings.

The terms "rear", "side" and "front" are to be interpreted throughout this specification as relative to a cutting direction of the cutting tool.

In a second aspect, there is provided a cutting tool assembly for a mining machine, said cutting tool assembly comprising:

a cutting tool holder comprising a body having a socket therein;

a cutting tool having:

a body comprising a cutting end for winning mineral from an ore body and a mounting end comprising a shank complementary with and engageable in the socket of the cutting tool holder,

a first bore in the body extending generally from the mounting end to the cutting end, and

one or more air inlet openings extending from an external surface of the body to the first bore; and a fluid injection unit associated with the first bore and adapted to direct fluid through the first bore for delivery to the cutting end of the tool.

The fluid injection unit may be secured to the cutting tool holder. In such embodiments, the fluid injection unit may be at least partially recessed in a second bore in the cutting tool holder. One end of the fluid injection unit may be housed in the second bore and an opposite end of the fluid injection unit may extend from the second bore and into a recess in the cutting tool. Alternatively, the fluid injection unit may be secured to the cutting tool. The fluid injection unit may be adapted to produce a jet of fluid.

A plurality of the air inlet openings may be provided. In some embodiments, the air inlet openings are generally circular in transverse cross-section. In other embodiments, the air inlet openings have a transverse cross section that is substantially longer in one dimension than in a direction substantially perpendicular thereto (eg. the air inlet openings may be oval in transverse cross section). In such embodiments, the longer dimension may be oriented in a direction that extends generally from the mounting end toward the cutting end.

At least one of the air inlet openings may be provided at a rear of the cutting tool. At least one of the air inlet openings may be provided at a side of the cutting tool. In one embodiment, air inlet openings are provided at a rear of the cutting tool and on both sides of the cutting tool.

A line of weakness may be provided in the cutting tool to define a predetermined failure point of the cutting tool. The line of weakness may be at least partially defined by one or more of the air inlet openings.

An end of the bore associated with the cutting end may terminate rearwardly of a cutting tip of the cutting tool.

Embodiments of the cutting tool and cutting tool holder will now be described, by way of example only, with reference to the accompanying drawings, in which:

Fig. 1 is a schematic side elevational view of a first embodiment of cutting tool assembly comprising a cutting tool and a cutting tool holder;

Fig. 2 is a cross sectional view of the cutting tool assembly of Fig. 1 ;

Fig. 3 is a schematic side elevational view of a second embodiment of cutting tool assembly comprising a cutting tool and a cutting tool holder; and

Fig. 4 is a cross sectional view of the cutting tool assembly of Fig. 3.

Referring to Figs. 1 to 4, there is provided a cutting tool assembly 10 for a mining machine. The cutting tool assembly 10 comprises a cutting tool holder 12 comprising a body 14 having a socket 16 therein. The assembly 10 also comprises a cutting tool 18 having a body 20 comprising a cutting end 22 for winning mineral from an ore body and a mounting end 24 comprising a shank 26 complementary with and engageable in the socket 16 of the cutting tool holder 12.

A first bore 28 is provided in the cutting tool body 20. The bore 28 extends generally from the mounting end 24 to the cutting end 22 of the tool 18 to terminate slightly rearwardly of a cutting tip 29 of the tool. A plurality of air inlet openings 30 extend from an external surface of the tool body 20 to the bore 28.

A fluid injection unit 32 is partially recessed in a second bore 34 in the cutting tool holder 12 and is secured to the cutting tool holder 12. An upper end of the fluid injection unit 32 extends from the second bore 34 and is housed in a recess 35 in the cutting tool 18. The fluid injection unit is adapted to direct a jet of water through the first bore 28 for delivery to the cutting end 22 of the tool. As water is injected through the first bore 28, negative pressure is generated in the air inlet openings 30 and draws external air through the air inlet openings 30 and into the first bore 28, where the air mixes with the water to facilitate dispersion of the water.

In the Fig. 1 and 2 embodiment, the air inlet openings 30 are generally circular in transverse cross-section, with two openings 30 being provided at the rear of the cutting tool 18 and two openings 30 being provided on each side of the cutting tool. The combined cross sectional area of the air inlet openings 30 is substantially larger than the cross sectional area of the first bore 28.

In the Fig. 3 and 4 embodiment, however, the air inlet openings 30 are oval in transverse cross section such that their cross section is substantially longer in one dimension than in a direction substantially perpendicular thereto. Moreover, in the Fig. 3 and 4 embodiment, the longer dimension of the air inlet openings 30 is oriented in a direction that extends generally from the mounting end 24 toward the cutting end 22 of the tool, which may aid in self-cleaning of the air inlet openings 30 to reduce the likelihood of their becoming blocked by mining debris. In view of their larger volume, a single opening 30 is provided at the rear and on each side of the cutting tool in the Fig. 3 and 4 embodiment. As with the Fig. 1 and 2 embodiment, the combined cross sectional area of the air inlet openings 30 of the Fig. 3 and 4 embodiment is substantially larger than the cross sectional area of the first bore 28.

The cutting tool 18 also includes a line of weakness 40 defined by a reduced thickness area around the body of the cutting tool 18. The line of weakness 40 is provided to define a predetermined failure point of the cutting tool 18. One or more of the air inlet openings 30 may pass through the line of weakness 40, such that the air inlet openings 30 at least partially define the line of weakness 40. It will be appreciated that the illustrated tool and tool assembly provide at least the following advantages:

• providing the bore 28 and air inlet openings 30 on the tool 18 means that a tool 18 can be changed if the bore 28 or air inlet openings 30 become blocked, rather than requiring the tool holder 12 to be replaced as would be required if the bore and openings were provided instead in the tool holder 12;

• any weakening created by the presence of the bore 28 and openings 30 is present in the tool 18 rather than in the tool holder 12, which is important given that the tool holder 12 is intended to have a longer service life than the tool 18;

· providing elongate air inlet openings 30 may assist with self-cleaning and reduce the likelihood of blockages by mining debris;

• water from the fluid injection unit 32, mixed with air from the air inlet openings 30, flows through the tool 18 for injection close to the area where incendive sprarking can take place during mining. Accordingly, improved protection against frictional ignition is provided;

• the fluid injection unit 32 is well protected by being housed in a recess on the underside of the tool 18. Accordingly, there is a reduced risk of the fluid injection unit becoming blocked by mining debris or damaged, which reduces downtime of the mining machine and increases the probability of the water/air mixture reaching its target area;

• provision of the air inlet openings 30 also reduces the amount of water that would otherwise be required from the fluid injection unit 32, since the air inlet openings 30 facilitate dispersion of water injected from the fluid injection unit 32;

· provision of the air inlet openings 30 facilitates use with a low pressure water supply, which reduces capital cost.

It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the above-described embodiments, without departing from the broad general scope of the present disclosure. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive. Examples of possible variations and/or modifications include, but are not limited to:

• the fluid injection unit may be secured to the cutting tool 18, for example in the recess 35 or in the first bore 28, instead of to the cutting tool holder 12; and/or · the fluid injection unit 32 being adapted to produce a spray of fluid instead of a jet of fluid.