Adjustable lawn sprinkler

Claim 1

IN A LAWN SPRINKLING SYSTEM HAVING AN UNDERGROUND CONDUIT SUPPLIED BY WATER UNDER PRESSURE AN ADJUSTABLE HEIGHT SPRINKLER DEVICE CONNECTED TO SAID CONDUIT AND ADAPTED TO BE EXTENDED UPWARD THEREFROM TOWARD THE GROUND LEVEL, COMPRISING: AN OUTER TUBULAR MEMBER RIGIDLY ATTACHED TO SAID CONDUIT AND HAVING A SERIES OF INTERNAL THREADS ON ITS INNER WALL; AND INNER TUBULAR MEMBER WITH AN ENLARGED PORTION OF AN INCREASED DIAMETER AT ITS LOWER END AND A SERIES OF EXTERNAL THREADS ON SAID ENLARGED PORTION, SAID INNER AND OUTER TUBULAR MEMBERS BEING CONNECTED TOGETHER BY SAID THREADS, SO THAT SAID INNER TUBULAR MEMBER IS AXIALLY MOVABLE WITHIN SAID OUTER TUBULAR MEMBER; A SPRINKLER HEAD ATTACHED TO THE UPPER END OF SAID INNER SLEEVE MEMBER; AND SEALING MEANS FOR PROVIDING A FLUID-TIGHT SEAL BETWEEN SAID INNER AND SAID OUTER TUBULAR MEMBERS INCLUDING AN INWARDLY EXTENDING LIP PORTION ON THE UPPER END OF SAID OUTER TUBULAR MEMBER; AN ANNULAR WASHER RETAINED BETWEEN SAID LIP PORTION AND THE UPPERMOST OF SAID INTERNAL THREADS ON SAID OUTER SLEEVE MEMBER; AN O-RING ADJACENT SAID LIP PORTION AND RETAINED BY SAID WASHER, SAID WASHER BEING ADAPTED TO APPLY A UNIFORM AXIAL FORCE ON SAID O-RING TO PRESS IT TIGHTLY AGAINST SAID INNER AND OUTER TUBULAR MEMBERS THEREBY EFFECTING A FLUID-TIGHT SEAL IN RESPONSE TO THE WATER PRESSURE IN SAID CONDUIT; WHEREBY SAID O-RING ASSUMES ITS NORMAL SHAPE WHEN THE WATER PRESSURE IS REMOVED TO FACILITATE THE EASE OF ADJUSTMENT OF SAID INNER TUBULAR MEMBER WITHIN SAID OUTER TUBULAR MEMBER.