COAL CUTTERS

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CRAWLER CHAINS

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Overview Of Coal Cutter and Crawler Chains

In drill and blast sections in coal mines, it is common practice to provide a second free breaking face by cutting a horizontal slot in the face to be blasted. This is done using a coal cutter. The cutting is performed by a chain comprising a number of pick boxes into which are inserted tungsten carbide tipped picks (cutting tools). Cutting boxes are angled at five different angles (like the teeth of a saw) to provide a clearance for the chain to run in.

Once the coal face has been blasted, the broken coal is loaded into shuttle cars using gathering arm loaders. These loaders run on crawler chains (also known as Cat-tracks) which consist of a number of inter-linked segments or pads. These pads are hard wearing and provide excellent traction for the machine.

Types of Coal Cutter Chain

Two types of coal cutter chains are produced by Duraset .

Pick Screw Type

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Quick Release Type

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• Pick screw type.
  This is the traditional type where cutter picks are held in place by a pick screw.

• Quick release type.
  The quick release coal cutter chain was developed by Duraset and uses a quick release clip to secure the cutter pick in its pick box.

There are several advantages with this type of arrangement:

• Pick screws have to be torqued up in order to secure the pick in the pick box. The pick screw often works loose and picks are lost or rendered ineffective. The quick release system uses a securing clip which is simply knocked into its locating holes. The clip is always positioned on the front end of the pick box and is thus held in this position whilst cutting. The incidence of pick losses is greatly reduced or eliminated altogether.
• When a pick has to be changed because it has become blunt or damaged, it is often very difficult to undo the pick screw. This results in lost time and production. With the quick release system, changing a pick is quick and easy. Simply lever out the quick release clip, replace the old pick with a new one and knock in the quick release clip again.
• No special tools are required to install or remove the quick release clips.

Sizes

Next Page for details on Lacing Patterns .....

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