Method and apparatus for soinc jarring with reciprocating masss oscillator

Claim 1

IN APPARATUS FOR LOOSENING A FISH STUCK AT A POINT BELOW ITS UPPER END IN A BORE HOLE, THE COMBINATION OF: A GRAPPLING TOOL ADAPTED TO RIGIDLY ENGAGE THE UPPER END OF THE FISH, A DRILL COLLAR HAVING A VERTICAL LONGITUDINAL AXIS, SAID COLLAR BEING RIGIDLY COUPLED AT ITS LOWER END TO SAID GRAPPLING TOOL AN ACOUSTIC VIBRATION GENERATOR LOCATED ADJACENT THE UPPER END OF SAID DRILL COLLAR COMPRISING A MASS ELEMENT ROTABLE ON AND LINEARLY RECIPROCABLE ALONG SAID VERTICAL LONGITUDINAL AXIS, A NON-ROTATABLE MEMBER ADAPTED FOR CORRESPONDING RECIPROCATION ALONG SAID AXIS, CAM MEANS BETWEEN SAID MASS ELEMENT AND SAID NONROTATABLE MEMBER FOR CONVERTING ROTATION OF SAID MASS ELEMENT INTO AXIAL VIBRATION OF SAID MASS ELEMENT AND OF SAID NON-ROTATABLE MEMBERS, SAID NON-ROTATABLE RECIPROCABLE MEMBER BEING COUPLED TO SAID DRILL COLLAR FOR TRANSMISSION OF RECIPROCATING FORCE TO THE UPPER END THEREOF TO SET UP IN SAID COLLAR AND FISH AN ACOUSTIC STANDING WAVE, AN INERTIA COLLAR ADAPTED TO BE LOWERED INTO THE BORE HOLE ON A ROTATABLE DRILL PIPE STRING, SUSPENDED FROM A ROTARY TABLE AT THE GROUND SURFACE, AND A TORQUE TRANSMITTING SPRING CONNECTING SAID INERTIA COLLAR AND SAID ROTATABLE MASS ELEMENT OF SAID WAVE GENERATOR, SAID SPRING BEING YIELDABLE IN A VERTICAL DIRECTION TO ISOLATE SAID INERTIA COLLAR FROM VIBRATION TRANSMITTED UPWARDS FROM SAID GENERATOR.