As shearers move up and down the face, trapping shoes attach the shearer to the haulage rack system joined to the AFC. A new type of trapping shoe developed by Bucyrus offers numerous advantages over the conventional design, the company says, including longer service life, greater flexibility, faster replacement and greater safety and ease of handling during replacement.
All this helps lower operating costs. The new patent-pending trapping shoe continues the Bucyrus principle of designing products with separate structural and wear parts to allow quick and easy replacement of surfaces subject to wear. The Trapping Shoe Ix (Insert Exchange) consists of one base shoe, two shoe inserts and two sets of insert retainers. The new design cuts the weight that has to be handled during replacement from more than 500 kg to less than 50 kg for each insert. It also dramatically reduces the time required for exchange of the two small shoe inserts instead of replacing the whole shoe. Because the weight handled is so much lower, change-out can take place anywhere along the face. Previously, this work had to be done at gate ends where heavy-lifting equipment was available.
While the base shoe is made of highly ductile material and is designed for structural strength, the insert is made of material with high abrasion resistance. The inserts have the same wear area as conventional shoes and are articulated, allowing them to move. This – combined with the fact that the shoe does not have to exert as much pressure, resulting in a lower point load – means less wear.
During field tests of the Ix trapping shoes conducted at Crinum mine (Australia) and a top-performing mine in northwestern Colorado (US), the service life of the trapping shoe inserts was found to be 50% longer than conventional trapping shoes. The inserts used in the test were cast steel, but inserts are now die-forged, which means that a further increase in service life can be expected.
Most Bucyrus shearers can be upgraded to the Trapping Shoe Ix, but suitability has to be established in each case.
