Instrumentation for in-mine testing of a deep cutting continuous coal mining machine

A Bureau of Mines low RPM, deep cutting continuous coal mining machine has been instrumented for in-mine testing. The cutting forces on selected bits and the structural loads on the machine as well as the dust and noise which occur during operation are measured and recorded to provide data needed to optimize the design of advanced equipment for high productivity and reduced airborne dust levels. Most of the parameters are sensed, conditioned and directly recorded on a multi-channel magnetic tape recorder. However, lack of a reliable communications path between the rotating cutting head and the other portions of the mining machine precluded such an approach to the recording of the tri-axial forces on the cutting bits. To overcome this problem, a completely self-contained, battery powered ''Bit Recorder'' suitable for installation and operation on the rotating head was developed. This instrument conditions, digitizes and stores the tri-axial bit force data in an integral solid state memory of large capacity. At any time up to several hours after a test run is completed the stored data may be transferred to the external tape recorder. The Bit Recorder is intrinsically safe and is fabricated and packaged to withstand the harsh vibration, dust andmore » abrasive material environment encountered on the cutting head. The entire data acquisition system meets MSHA requirements for in-mine testing. Computer programs have been developed for laboratory analysis of the tape recorded data. Excellent agreement between data sensed by the systems and that obtained by conventional measurements has been achieved.« less