Detachable structure and joint therefor

Claim 1

A JOINT IN A DEMOUNTABLE STRUCTURE COMPRISING: A VERTICAL COLUMN OF CHANNEL CROSS SECTION HAVING A WEB DISPOSED BETWEEN A PAIR OF FLANGES AND TWO VERTICAL ROWS OF EQUALLY SPACED MOUNTING SLOTS FORMED IN SAID WEB, EACH OF SAID MOUNTING SLOTS BEING ENLARGED AT ITS UPPER END AND HAVING A SMALLER TAPERED LOWER PORTION A FIRST CAMMING SURFACE; A HORIZONTAL BEAM OF CHANNEL CROSS SECTION HAVING A WEB DISPOSED BETWEEN A PAIR OF FLANGES, EACH OF SAID FLANGES BEING CORRESPONDINGLY NOTCHED SO AS TO ABUT SAID WEB AND ONE OF SAID FLANGES OF SAID VERTICAL COLUMN; TAB MEANS OF L-SHAPED CROSS SECTION HAVING ONE OF ITS LEGS FORMED TO DEFINE A PAIR OF HOOK-LIKE MEMBERS WHICH ARE SPACED APART BY THE SAME DISTANCE AS SAID MOUNTING SLOTS FORMED IN SAID WEB OF SAID VERTICAL COLUMN, EACH OF WHICH HAS A TAPERED PORTION FORMING A SECOND CAMMING SURFACE, AND THE OTHER ONE OF ITS LEGS SECURED TO SAID WEB OF SAID HORIZONTAL BEAM AT ITS END IN A POSITION SUCH THAT SAID VERTICAL COLUMN IS FORCIBLY URGED WITHIN SAID NOTCHED PORTION OF SAID FLANGES OF SAID HORIZONTAL BEAM BY THE COOPERATIVE ACTION OF SAID FIRST AND SAID SECOND CAMMING SURFACES WHEN SAID HOOK-LIKE MEMBERS ARE ENGAGED IN SAID MOUNTING SLOTS; SAID SLOTS BEING OF GREATER LENGTH LONGITUDINALLY OF SAID COLUMN THAN SAID TAB MEANS, THEREBY LEAVING A SPACE IN THE UPPER END BETWEEN THE TAB MEANS AND ONE END OF THE SLOT ENGAGED THEREWITH AND A SPRING MEMBER BEING MADE OF A RESILIENT STRIP MATERIAL AND HAVING A MAIN BODY PORTION WITH A U-SHAPED CONFIGURATION AND U-SHAPED REVERSED END LOOPS DISPOSED GENERALLY PARALLEL WITH THE MAIN BODY PORTION, SAID SPRING MEANS SERVING TO LOCK SAID BEAM AGAINST VERTICAL MOVEMENT IN THE ENGAGED MOUNTING SLOTS BY REASON OF THE PARALLEL PORTIONS OF THE SPRING MEANS MAIN BODY PORTION AND THE END LOOPS BEING INSERTED IN SAID SPACE IN THE UPPER END OF A PAIR OF SAID MOUNTING SLOTS TO FORM AN ABUTMENT FOR SAID BEAM.