Fluid sampler

Claim 1

APPARATUS FOR PROCURING AN UNCONTAMINATED SAMPLE OF FLUID AT A GIVEN DEPTH WITHIN A FLUID MEDIUM COMPRISING, IN COMBINATION, A CYLINDRICAL CASING CLOSED OFF AT OPPOSITE ENDS WITH UPPER AND LOWER CLOSURE PLATES; A CENTRAL BORE CUT THROUGH SAID UPPER CLOSURE PLATE; A PISTON ACCOMMODATED WITHIN SAID CASING AND HAVING A DIAMETER APPROXIMATELY EQUAL TO THE INTERIOR DIAMETER OF SAID CASING; A PISTON ROD CONNECTED AT ONE END TO SAID PISTON AND ADAPTED TO HAVE ITS OTHER END CONNECTED TO A LOWERING CABLE, SAID PISTON ROD HAVING A LENGTH SUCH THAT WHEN SAID PISTON IS IN CONTACT WITH THE LOWER END CLOSURE PLATE THE OTHER END OF SAID ROD PROJECTS THROUGH SAID CENTRAL BORE; MEANS FOR LATCHING SAID CASING TO SAID PISTON ROD SUCH THAT SAID PISTON IS RETAINED AGAINST SAID LOWER CLOSURE PLATE, SAID LAST-NAMED MEANS INCLUDING A COLLAR SECURED TO SAID PISTON ROD AT A POINT ADJACENT SAID OTHER END THEREOF, A PAIR OF PAWLS PIVOTALLY SECURED TO THE UPPER CLOSURE PLATE ON OPPOSITE SIDES OF SAID CENTRAL BORE AND BEING SPRING BIASED TO A VERTICAL POSITION, EACH OF SAID PAWLS HAVING A TOOTH PORTION WHICH IS IN LOCKING ENGAGEMENT WITH A RIM PORTION OF SAID COLLAR WHEN SAID PAWLS ARE IN SAID VERTICAL POSITION, AND AN ADJACENT SLANTED SURFACE WHICH, WHEN STRUCK BY A DOWNWARD FORCE, CAUSES SAID PAWL TO ROTATE BACKWARDLY TO DISENGAGE SAID TOOTH PORTION FROM LOCKING ENGAGEMENT WITH SAID RIM PORTION OF SAID COLLAR; A FILLING APERTURE CUT THROUGH SAID UPPER END CLOSURE PLATE A FLUID OF KNOWN COMPOSITION FILLING THE INTERIOR SPACE OF SAID CASING WHICH IS ABOVE SAID PISTON WHEN SAID CASING IS LATCHED TO SAID PISTON ROD; A WATER INLET APERTURE FORMED IN THE LOWER END CLOSURE PLATE; A CHECK VALVE CONNECTED TO SAID WATER INLET APERTURE FOR PERMITTING A FLOW OF FLUID INTO THE INTERIOR OF SAID CASING WHENEVER THE PRESSURE WITHIN SAID CASING IS A PREDETERMINED AMOUNT BELOW THE OUTSIDE PRESSURE; MEANS FOR UNLATCHING SAID CASING FROM SAID PISTON ROD WHEN SAID CASING IS SUPPORTED AT A GIVEN DEPTH WITHIN A FLUID MECHANISM BY A LOWERING CABLE ATTACHED TO SAID OTHER END OF SAID PISTON ROD WHEREBY SAID CASING DROPS DOWNWARDLY UNDER ITS OWN WEIGHT UNTIL SAID PISTON CONTACTS SAID UPPER END PLATE, THE RELATIVE MOVEMENT BETWEEN SAID PISTON AND SAID CASING OCCURRING WHEN SAID CASING IS SO UNLATCHED CAUSING THE FLUID STORED ABOVE SAID PISTON TO BE DISCHARGED THROUGH SAID FILLING APERTURE INTO THE SURROUNDING FLUID MEDIUM AND ALSO CAUSING AN EQUAL AMOUNT OF FLUID FROM SAID SURROUNDING FLUID MEDIUM TO FLOW THROUGH SAID CHECK VALVE AND WATER INLET APERTURE INTO THE INTERIOR OF SAID CASING; AND MEANS FOR DRAINING SAID CASING OF THE FLUID STORED THEREIN.