| 摘要 |
Mine roof supports have a fluidic logic control system for raising and lowering the supports and for advancing the supports in the form of a number of units one on each support. Each unit has a first OR gate which controls a first interface valve to cause the support to lower and advance itself, a second interface valve causing the support to rebrace itself controlled by a second OR gate interconnected with the first through an AND gate which receives inputs from the first OR gate and a sensor denoting that the advance has been completed, an AND gate receiving inputs from a sensor denoting that the support is rebraced and from the second OR gate to provide an input for the first OR gate of the next unit and a reset signal which is passed through a delay restrictor to reset the first OR gate of the support.
|
