The Cat® LatchFree® Dipper System is the first successful solution to the most common cause of rope shovel downtime. The system replaces the standard maintenance-intensive latch assembly with a durable steel link assembly mounted to the dipper back. The key to the design is the geometry of the locking mechanism. The unique arrangement makes it possible to locate the components away from the abrasive flow of material.
The system has been designed and field proven for a service interval of 3,000 hours, as compared to the standard system that requires adjustment as often as each shift. In addition to delivering greater uptime and lower maintenance costs, the system eliminates false trips—unplanned release of the dipper door—caused by dirt buildup or the need for shim adjustments. The result is fewer delays, consistent production and lower cost per ton.
The LatchFree Dipper System is currently available for Cat Electric Rope Shovels with dipper capacities of as large as 49 cubic meters (65 cubic yards) for 7495 Series shovels that meet machine configuration requirements. The system proved its performance on a Cat 7495 HF loading Cat 797 trucks in the challenging oil sands of Alberta, Canada.
Moving sticky material
“We’re giving it the best challenge—with the environment along with the volumes we mine every day—to test this product to the limit,” said Dino Colbourne, Maintenance Manager of Shell Albian Sands, during field testing of the LatchFree Dipper System.
“We’ve got a lot of sticky, wet dirt,” said Darrell Lewis, Maintenance Team Lead for Albian Sands. “That can create a lot of problems with either the bucket or with the amount of force it takes for the machine to move through it.”
In the harsh conditions of the oil sands, standard dipper latches required maintenance about two times per day and had a significant number of false trips.
“To adjust door latch shims, we have to walk the shovel out two times the face height, so the process takes 15 to 20 minutes. That’s 10 truckloads of bitumen we’ve lost,” said Keith Black, Albian Sands Mine Manager.
“If you’re using the LatchFree [dipper], you swing to the truck with confidence that it’s not going to trip,” said Mikita Burton, Shovel Operator at Albian Sands. “So you can swing faster and don’t lose time at the face.”
“We don’t see the system going down or having to repair it,” said Andrew Mackinowski, Operations & Maintenance Coordinator at Albian Sands. “Predictability in maintenance and maintenance intervals is a huge benefit.”
“I see this system as offering a great opportunity to increase productivity at the mining face and to take a lot of our maintainers out of the line of fire,” concluded Colbourne.
For more information about the Cat LatchFree Dipper System, contact the local Cat dealer, talk to the shovel team and see the LatchFree System at the Caterpillar exhibit during MINExpo 2016, or go to: www.cat.com/mining
