Highwall mining is a form of surface mining, in which spaced apart tunnels (sometimes called holes or entries) are cut into an exposed face of the seam at predetermined intervals to create the pillars for supporting the overburden. A typical highwall mining system is comprised of a cutter (or miner module), a conveying system and a main miner (or launch module). The cutter cuts into a mineral seam and is forced into the cut by pushing a series of conveyor sections, also called “push beams” or “conveyor pans.”
It is common in the art of highwall mining to use push beams to form a part of a highwall mining system. Generally, push beams are essentially boxes that contain a type of conveying mechanism, such as augers, that move the minerals out of the mine. The basic approach is shown and described in U.S. Pat. No. 4,014,574 to Todd.
To provide an efficient and effective highwall mining system, the push beams must interconnect in such a way as to withstand the substantial forces present during a typical mining operation. Specifically, the push beams must be rigid in the horizontal plane to prevent the cutter from going off target and breaking through into the last cut. This is normally accomplished by interconnecting the push beams together using “dog-bone” couplers that were retained using separate removable pins as shown in U.S. Pat. No. 6,035,997 to Heninger et al. or like mechanisms, such as nut and bolt combinations.
Although removable pins or like mechanisms may be used to retain the dog-bone shaped couplers interconnecting the push beams, limitations remain. Specifically, in the harsh conditions often encountered in the mining operation, these types of arrangements are susceptible to becoming damaged. Further, the removable pins or like mechanisms are easily lost or misplaced, which is troublesome to the mining operation for obvious reasons, such as cost and delay.
Past push beams used in highwall miners are also typically interconnected with abutting vertical faces such that relative articulation was not possible (or was only possible to a very limited extent, such as the result of part tolerances). Even when such limited articulation was possible, the abutting ends of the push beams were generally square and thus prevented any articulation when under compressive loading (see the '574 patent to Todd; col. 14, line 68 to col. 15, line 1, which states that the gap between the push beam couplers “allows for a slight flexing movement between the modules . . . when they are not under a longitudinal compressive load.”) (emphasis added). This inability to freely articulate, especially during the application of a longitudinal compressive load, may create a significant problem when the entry is uneven or undulating, since the push beams may “bind up” and become stuck.
Accordingly, the art of mining has a need for an improved arrangements for coupling conveyor sections. Specifically, a need exists for improved latching mechanisms for interconnecting the conveyor sections that minimizes damage in harsh mining conditions and reduces costs and delays due to lost or misplaced parts. A further need exists for a coupling that permits adjacent conveyor sections to articulate in a smooth and controlled manner.