Terex Mining has introduced some major innovations to two additional options for its R20T hydraulic track drill-the carousel rod changer and single rod changer options. The SKF rotary blasthole drill has also benefitted from a carousel innovation, allowing a quick change from rotray to DTH drilling. And, in Australia, a specially adapted SKF is now a very quiet drill.

Designed as a field-serviceable, high-production drill with, what Terex describes as “the largest drill pattern available” (36 m2), the R20T further expands its capabilities with these options. Both ease maintenance requirements with features such as corrosion-resistant, self-lubricating coatings on normal wear parts and pivot pins, which eliminate the need for lubrication. This provides long life and is one less area for customers to maintain.

The carousel rod changer will hold five rods in the carousel and one 6.1 m in the feed for a total of six rods. The carousel can change either 3.7 m or 4.3 m steel. The single rod changer will hold a 3.7 m or 4.3 m rod in the magazine and a 6.1 m starter steel in the feed.

The unique carousel and single rod changer gate design aims to reduce maintenance requirements by eliminating parts and reducing rod change time. “Competitive drills require an added step of opening the gate before they can move the drill steel, but with the R20T’s carousel and single rod changer, this step is unnecessary,” Terex reports.

Addressing the time-consuming effort formerly required to change the size of the steel in a rod changer, the rod gripper design accommodates 38 mm, 45 mm and 51 mm drill steel. This design allows for minimal part change, and reduced changeover time and cost in the field. Other time- and money-saving features found on the carousel and single rod changer include:

• Weight and number of parts is reduced due to a new hose-tensioner design incorporated into the upper carousel mount; also neatly routes hoses and ensures proper alignment, helping increase hose life; the single rod changer has a similar tensioner that offers the same benefits
• Improved rod-change time as a result of the powerful dual rod grippers
• More efficient dust collection from a multi-position, pre-cleaner mount
• Proper rod position is assured and vibration-prone sensor failures are eliminated on the carousel rod changer due to the integrated carousel indexing and locking; also reduces component part complexity and count (the single rod changer uses a hydraulic cylinder to swing the rod in or out)
• Components weigh less, providing for a full complement of steel in the carousel (six steels and one in the feed) and single rod changer to maximize hole depth.

When Osvaldo Pires, Product Manager-Rock Drills and Application Manager-Drills, arrived at a mine in Brazil to oversee the delivery of two SKF drills, he had no idea the visit would be a catalyst for him to design an entirely new Terex product. After the drills were delivered in August 2006, the customer stated he needed the drills to perform a certain function, and Pires took it upon himself to make it happen.

Because of differences in rock consistency-soft, intermediate-soft and hard, the customer needed a drill that could quickly switch between tricone drilling for softer rock and down-the-hole (DTH) drilling for very hard rock. With the drills’ existing setup, it would take two to three hours, sometimes as much as half a shift, and the use of heavy equipment to convert the drills between the two types of drilling methods.

“I talked to a few people and asked them in detail what they needed the machine to do,” Pires recalls. Viewing this as an opportunity to engineer a completely new innovation that would help Terex customers, Pires worked with two draftsmen at a local dealer. In the end, he says, “We had to manufacture four pieces and modify one piece, and we were able to produce this modification exactly as the customer wanted.”

A job that would normally take up almost a half-shift of time, manpower and equipment now takes less than five minutes and is performed by the operator inside the cab, making this switchover extremely safe. “Everything is set up in the carousel the way the customer wants so they just have to switch over and start drilling the other way,” Pires says. “There is no lost time.”

“The modification started to generate a lot of interest, so I contacted our engineering department and suggested we patent this device,” Pires says of his invention, which hasn’t needed any adjustments since it was originally designed. It is now offered as a Hammer-Tricone Pipe Rack for the Terex SKF and SKS drills and will be available on the SKL in the near future. Terex says it “is the first drill manufacturer to offer this feature to the industry.”

Xstrata Coal needed a sound-suppressed drill for its Glendell mine in Australia to meet environmental standards when operating within close proximity to residential areas. It was required that the sound level be no more than 114 dBA, with an in-cab rating of 75 dBA or less. However, its Terex SKF drill was rated at a sound power level of 121 dBA at source with a standard cab rating of 78 dBA.

Working with an external acoustic engineering firm, Terex Mining developed a sound-suppression package that encapsulated the power train (including gearboxes, engines, compressors and coolers), achieving a of 111 dBA at source. A new modified cab achieved an in-cab rating of 65 dBA. To ensure these alterations did not affect the SKF’s ease of maintenance, all panels, mechanisms, etc., were either hinged or lightweight for easy removal and access.

Terex also manufactured an oversized muffler that not only reduced noise but was also in keeping with environmental emission standards. Further noise-reduction adjustments were made to the dry dust suppression system, which uses fans spinning at 2,500 rpm that caused a spike in the noise readings.

Xstrata quickly put the modified drill to work at Glendell from where Tony Israel, the mine’s Operations Manager, commented, “At Glendell, we have an absolute commitment to our environment and community. By working closely with us, Terex has delivered sound-suppression levels on our SKF drills that exceeded our expectations. This aligns with our goal of ‘beyond compliance.'”