Adjustable automatic control for a pump

Claim 1

IN COMBINATION WITH A LIQUID CONTAINING RECEPTACLE INCLUDING A LIQUID INLET AND AN ELECTRIC PUMP FOR EXTRACTING LIQUID FROM SAID RECEPTACLE AND HAVING AN INLET OPENING INTO THE RECEPTACLE; A PUMP CONTROL COMPRISING A BLOCK OF ELECTRICAL INSULATING MATERIAL, SAID BLOCK BEING INTERNALLY RECESSED, AN UPPER ELECTRODE AND A LOWER ELECTRODE EXTENDING INTO THE RECESS OF THE BLOCK, A LIQUID OF ELECTRICAL CONDUCTING MATERIAL PARTIALLY FILLING THE RECESS AND NORMALLY DISPOSED BELOW THE ELECTRODES, COMPRESSIBLE PRESSURE RESPONSIVE MEANS COMMUNICATING WITH THE BOTTOM PORTION OF THE RECEPTACLE AND WITH A PART OF THE RECESS OF THE BLOCK FOR PRESSURING SAID PART OF THE RECESS WHEN THE LIQUID LEVEL RISES IN THE RECEPTACLE TO CAUSE THE LIQUID IN THE RECESS TO RISE INTO ENGAGEMENT WITH THE LOWER ELECTRODE AND THEREAFTER INTO ENGAGEMENT WITH THE UPPER ELECTRODE, AND AN ELECTRIC SYSTEM HAVING A CIRCUIT INCLUDING THE PUMP MOTOR AND SAID ELECTRODES AND WHICH IS CLOSED BY THE LIQUID OF THE RECESS CONTACTING BOTH ELECTRODES, SAID ELECTRIC SYSTEM INCLUDING A THIRD ELECTRODE DISPOSED IN A BOTTOM PART OF THE RECESS AND FORMING WITH SAID LOWER ELECTRODE A SECOND HOLDING CIRCUIT FOR RETAINING SAID FIRST MENTIONED CIRCUIT CLOSED, AFTER THE INITIAL CLOSING THEREOF, UNTIL THE LIQUID OF THE RECESS MOVES OUT OF CONTACT WITH THE LOWER ELECTRODE, SAID RECESS OF THE BLOCK HAVING A VENT OPENING TO THE ATMOSPHERE AND DISPOSED ABOVE THE UPPER AND LOWER ELECTRODES, AND MEANS FOR SELECTIVELY CLOSING SAID VENT FOR IMPEDING THE RISE OF THE LIQUID IN THE RECESS OR FOR IMPEDING THE FALL OF SAID LIQUID.