Oil field device for determining the liquid level of a mud pit

Claim 1

A SELF-CONTAINED TRANSLATIVE DEVICE USED IN CONNECTION WITH OTHER COMPONENT PARTS FOR INDICATING THE LIQUID LEVEL IN A MUD PIT IN OIL WELL DRILLING OPERATIONS, COMPRISING A CASING HAVING UPPER AND LOWER ENDS, A FRONT, A REAR AND TWO SIDES, A SHAFT EXTENDING THROUGH BOTH SIDES OF SAID CASING AND ROTATABLY MOUNTED THERETO, A LEVER FIXABLY ATTACHED AT ITS UPPER END TO SAID SHAFT OUTSIDE OF SAID CASING, A CAM FIXABLY ATTACHED TO SAID SHAFT INSIDE OF SAID CASING, SAID LEVER HAVING A LOWER END ADAPTED SO THAT A FLOAT RESTING ON A BODY OF LIQUID MAY BE FIXEDLY ATTACHED THERETO, A PIVOT MECHANISM PIVOTALLY ATTACHED TO THE INSIDE OF SAID CASING AND RESTING ON SAID CAM, A PLUNGER ROD LOCATED ABOVE AND RESTING ON SAID PIVOT MECHANISM AND ADAPTED TO RISE AND FALL AS SAID SHAFT AND CAM ARE ROTATED WITH THE RISE AND FALL OF SAID FLOAT AND THE LIQUID LEVEL OF THE BODY OF LIQUID, AN AIR INLET PIPE ADAPTED TO RECEIVE PRESSURIZED AIR AND AN OUTLET AIR PIPE ADAPTED TO DISCHARGE PRESSURIZED AIR, EACH OF SAID PIPES EXTENDING THROUGH SAID CASING NEAR ITS UPPER END, A VALVE SEPARATING SAID PIPES WITHIN SAID CASING, SAID PLUNGER ROD HAVING AN UPPER END OPERATING SAID VALVE, SAID VALVE BEING ADAPTED TO VARY THE