Joint and lock mechanism for telescoping spar

Claim 1

IN A TELESCOPING SPAR OF A TYPE WHICH STANDS UPRIGHT WHEN IN ITS OPERATING POSITION, IN COMBINATION: A LOWER SPAR SECTION PROVIDED ADJACENT ITS UPPER END WITH UPWARDLY FACING SUPPORT MEANS, AN UPPER SPAR SECTION RECEIVED FOR TELESCOPING SLIDE MOVEMENT WITHIN THE LOWER SECTION, A RING SEATED ON SAID SUPPORT MEANS WITH SAID SUPPORT MEANS PROVIDING A THRUST MOUNTING THEREOF, MEANS CARRIED BY THE UPPER END OF SAID LOWER SPAR SECTION PROVIDING A JOURNAL MOUNTING FOR SAID RING ALLOWING THE RING TO TURN ABOUT THE CENTER OF THE LOWER SPAR SECTION AS AN AXIS, SAID RING INCLUDING A SET OF SPACED INTERNAL TEETH FORMED ON THE INNER RADIAL PERIMETER THEREOF, A SET OF SPACED EXTERNAL TEETH CARRIED ON THE OUTER RADIAL PERMITER OF THE UPPER SECTION, SAID EXTERNAL TEETH COMPLEMENTING SAID INTERNAL TEETH AND BEING POSITIONED TO LIE IMMEDIATELY ABOVE THE INTERNAL TEETH WHEN THE SPAR IS EXTENDED TO ITS FULL HEIGHT, THE TEETH OF EACH OF SAID TWO SETS OF TEETH HAVING A WIDTH SUCH AS TO PASS FREELY THROUGH THE INTERSTICES WHICH LIE BETWEEN THE TEETH OF THE OTHER SET, MEANS CARRIED BY THE UPPER END OF THE LOWER SPAR SECTION FOR KEEPING THE RING FROM BEING DISPLACED UPWARDLY, AND MEANS MOUNTED ON THE UPPER END OF SAID LOWER SECTION FOR TURNING THE RING TO SELECTIVELY POSITION THE INTERNAL TEETH THEREOF IN LINE EITHER WITH SAID EXTERNAL TEETH OR THE INTERSTICES THEREBETWEEN.