Jarring tool

Claim 1

A FISHING TOOL FOR JARRING A STRUCK WELL PIPE AS THE PIPE ON WHICH THE TOOL IS SUPPORTED IN THE WELL IS ROTATED COMPRISING, (A) AN OUTER TUBULAR BODY HAVING CONNECTOR MEANS FOR CONNECTING THE BODY TO THE STRUCK PIPE, (B) A MANDREL ROTATABLE RELATIVE TO SAID CONNECTOR MEANS AND CONNECTED TO THE WELL PIPE FOR ROTATION THEREWITH, (C) A RESERVOIR MEANS IN THE TOOL FOR CONTAINING PRESSURE FLUID, (D) A PISTON MEMBER SLIDABLE ON AND ROTATABLE WITH SAID MANDREL, (E) SAID PISTON MEMBER BEING EXPOSED TO THE PRESSURE FLUID THE RESERVOIR MEANS SUCH THAT THE FLUID PRESSURE THEREIN CAN ACT ON ONE END OF SAID PISTON MEMBER SO AS TO BE URGED LONGITUDINALLY OF SAID CONNECTOR MEANS AND SAID MANDREL BY THE PRESSURE FLUID IN SAID RESERVOIR MEANS, (F) SERRATIONS ON SAID BODY AND SAID PISTON MEMBER WHICH UPON ROTATION OF SAID MANDREL URGE SAID PISTON MEMBER UPWARDLY AGAINST THE FLUID PRESSURE IN SAID RESERVOIR MEANS TO COMPRESS THE FLUID THEREIN, (G) MEANS ON SAID MANDREL AND ENGAGEABLE WITH SAID BODY DURING ROTATION OF THE MANDREL RELATIVE TO SAID BODY FOR TRANSMITTING THE WEIGHT OF THE MANDREL AND PIPE CONNECTED THERETO TO THE SERRATIONS ON SAID BODY, AND (H) SAID SERRATIONS ON SAID PISTON MEMBER BEING CIRCUMFERENTIALLY AND LONGITUDINALLY MOVABLE RELATIVE TO THE SERRATIONS ON SAID BODY UPON SUCH ROTATION OF SAID MANDREL FOR OBTAINING ALTERNATE UPWARD AND DOWNWARD LONGITUDINAL MOVEMENTS OF SAID PISTON MEMBER UPON CONTINUED ROTATION OF SAID MANDREL WHEREUPON THE FLUID PRESSURE CAUSES SAID PISTON MEMBER TO DELIVER SUCCESSIVE JARRING BLOWS TO SAID BODY TO AID IN RELEASING THE STRUCK WELL PIPE CONNECTED THERETO.