| 摘要 |
<p>This invention provides mine equipment for sensing the advance of mobile equipment, particularly on longwall face conveyors the equipment comprises two mine roof supports provided with sensor means for sensing relative movement between the associated roof supports and an elongate bar component secured to the conveyor and extending between the two supports in a direction rearwardly of the conveyor. The elongate component is magnetized so that a magnetic field is induced adjacent thereto, the induced magnetic field intensity varying longitudinally of the elongate component.</p> |
