Filter press control circuit

It uses one button to open and tighten the plate and frame of the filter press.
  In the figure, SQi and SQ2 are limit switches . The filter press is opened, the plate and frame are completely opened, and SQ2 is pressed down. When the board frame moves
in the pressure direction and leaves SQ2, SQ2 is reset. When the board frame runs to SQi, so, the contacts are disconnected. When the board frame moves in the sound-opening direction and the board frame leaves sQ], SQi is reset.