Spring biased well jar

Claim 1

IN A WELL JAR INNER AND OUTER TELESCOPINGLY ARRANGED TUBULAR PARTS MOVABLE LONGITUDINALLY RELATIVE TO EACH OTHER, MEANS FOR CONNECTING ONE OF SAID PARTS TO AN OPERATING STRING, MEANS FOR CONNECTING THE OTHER OF SAID PARTS TO AN OBJECT STUCK IN A WELL BORE, COACTING IMPART FACES ON THE PARTS POSITIONED FOR CONTACT WHEN THE PARTS REACH THE LIMIT OF THEIR RELATIVE LONGITUDINAL MOVEMENT IN ONE DIRECTION, SAID INNER PART HAVING AN EXTERNAL LONGITUDINAL GROOVE AND A LATERAL EXTENDING U-SHAPED NOTCH OPENING INTO THE GROOVE AND FORMED WITH CURVED OUTWARDLY FLARING SIDE WALLS, ROLLER MEANS ROTATABLY MOUNTED ON THE OUTER PART EXTENDING INTO THE GROOVE AND ENGAGEABLE WITH THE INNER PART OF HOLD THE PARTS AGAINST RELATIVE ROTATION, AND POSITIONED FOR MOVEMENT INTO SAID NOTCH UPON RELATIVE ROTATION OF THE PARTS IN ONE DIRECTION WHEN THE PARTS ARE IN A PREDETERMINED RELATIVE LONGITUDINAL POSITION WITH SAID FACES OUT OF CONTACT TO HOLD THE PARTS AGAINST RELATIVE LONGITUDINAL MOVEMENT, AND FOR ROLLING MOVEMENT IN CONTACT WITH ONE OF SAID SIDE WALLS OUT OF SAID NOTCH TO IMPART RELATIVE ROTATION TO THE PARTS IN THE OTHER DIRECTION UPON THE EXERTION OF A PREDETERMINED FORCE TO THE PARTS TENDING TO MOVE THE PARTS LONGITUDINALLY RELATIVE TO EACH OTHER.