Choosing your Roller & Bracket
The following guidelines should help you make decisions on the right equipment to buy. It is important to note that every product offered by Elite Mining serves its own purpose and it is finding the right combination between roller and bracket that will benefit the customer the most by saving costs in the long run.
Choosing the Roller
There are 3 main criteria for choosing the correct type of roller:
1. Standard (STD) or Special (SP) Roller
2. Long Shaft (LS) or Short Shaft (SS)
3. Rail Gauge and Length of Roller
Standard (STD) or Special (SP) Roller
Elite manufactures two different rollers. The standard (STD) roller has tapered ends where the (SP) roller has shouldered ends for better rope restriction. To determine which roller to use one will have to investigate if the rope deviates off the rollers installed in the decline. If the rope does not drift off the roller at any stage then a STD roller would be installed, likewise if there is a lot of drift one would install an SP roller. A deviation off the roller is most commonly found in longer declines where the rail installations are not installed in a straight line. It is not uncommon to install both type rollers on one decline.
Long Shaft (LS) or Short Shaft (SS)
Elite manufactures two types of shafts for the standard and SP rollers namely the Long Shaft (LS) and the Short Shaft (SS). Elite identified that a common problem occurring on declines was that the rope was drifting off the roller and was getting stuck between the roller ends and the Bracket mounting ears causing damage to the rope, roller and bracket. Elite thus developed the shorter shaft which eliminates this problem by decreasing the distance between the roller and the bracket.
The long shaft has been a common standard and will fit in to most of the older brackets installed. It is safe to say that only the new Elite type brackets will be of a short shaft. A good way to determine what type of shaft is being used is to check the distance between the roller ends and the bracket ears, also the shaft length from roller to shaft end is 30mm where the short shaft is only 15mm in length.
Rail Gauge (RG) and Length
The rail gauge is the distance between the opposing heads of the rails installed in the decline. The South African industry works with 3 main Rail Gauges the narrowest being the 610GR and increasingly a 762RG and a 914RG. This length is important and determines the length of your roller and the bracket. A 600mm roller would not be able to fit in between a 610RG. The ultimate length of the roller is a judgment call on how well the rope behaves when in operation. A very steady and centered rope would require a much shorter roller than a shaft with excessive rope movement. Please see the roller dimension chart to identify the roller you are require
Roller Coding
Choosing the Bracket
Elite has designed various brackets to suit most decline shafts in the South African mining industry. The following guidelines will determine the type of bracket to use in a particular shaft.
1 Rail Gauge (RG)
2 Height Clearance of transport vehicles
3 Rail and footwall configuration
Rail Gauge (RG) and Length
The rail gauge is the distance between the opposing heads of the rails installed in the decline. The South African industry works with 3 main Rail Gauges the narrowest being the 610GR and increasingly a 762RG and a 914RG. This is important and as it determines the length of your bracket when using rail clamping brackets.
If you are using a bracket that is not rail clamping it would be your roller which determines the length of your bracket.
Height Clearance of transport vehicles
Some transport vehicles operating on the declines may have different ground clearances which could determine the type of bracket to use. In most circumstances the clearances are big enough to install the standard type brackets. Vehicles with a particularly low ground clearance will require a dropped bracket to be installed such as the ::lowered channel bracket:: (link to this product)
Rail and footwall configuration
Declines have been designed in many different ways to compliment the shaft and its purpose. These designs may greatly influence the choice of bracket you will use.
Rails are commonly sill mounted, with a pre determined sill spacing supporting the rail. In this instance a channel bracket may be used as it can be attached to the underside of the rails with clamping arrangements on the outside foot of the rail. The angle bracket can also be used and is mounted on the inside foot of the rail.
The flat based brackets are used in declines with foot wall mounted rails where the foot of the rail is not accessible for mounting. Some declines have dug-outs at determined distances to cater for rail clamping brackets. In these circumstances Elite would suggest using the angle bracket with splash plate. These declines are very hard to maintain as they suffer from water and debris build up which can cause pre mature wear of the rollers.
Rails can also be mounted on I-Beams acting as sills. Brackets have also been designed to clamp on to the I-Beam.
Bracket Coding
