Explosive-actuated apparatus for taking cores

Claim 1

A CORE TAKER FOR USE IN OIL WELLS OR THE LIKE INCLUDING, IN COMBINATION, A WIRE LINE, AN EXPLOSIVE JAR SECURED TO THE LINE AND HAVING MEANS FOR FIRING THE SAME BY MANIPULATION OF THE LINE, A CYLINDER ATTACHED TO AND LOCATED BELOW SAID EXPLOSIVE JAR AND HAVING A CORE BARREL MOUNTED FOR VERTICAL MOVEMENT THEREIN, A GREASE CUSHION LOCATED BETWEEN SAID CORE BARREL AND SAID CYLINDER, MEANS FOR DRIVING THE CORE BARREL DOWNWARDLY IN SAID CYLINDER WHEN THE JAR IS FIRED, A HEAD ATTACHED TO THE LOWER END OF SAID CYLINDER HAVING A VERTICAL PASSAGEWAY THERETHROUGH IN AXIAL ALIGNMENT WITH SAID CORE BARREL WHEREBY SAID CORE BARREL MAY MOVE DOWNWARDLY THERETHROUGH WHEN THE JAR IS FIRED, SAID HEAD ALSO HAVING MEANS FOR SEATING IN A DRILL BIT AND FOR POSITIONING THE CORE TAKER WITH RESPECT TO THE BIT SO THAT THE CORE BARREL MAY MOVE VERTICALLY DOWNWARDLY OUT OF SAID PASSAGEWAY AND THROUGH THE BIT, AND MEANS FOR KEEPING SAID CORE BARREL EMPTY UNTIL THE JAR IS FIRED.