Demountable frame for an advertising sign

Claim 1

A DEMOUNTABLE FRAME FOR AN ADVERTISING SIGN TO BE MOUNTED ON A VERTICAL SURFACE COMPRISING, A RECTANGULAR BRODER FRAME CONSISTING OF CHANNEL MEMBERS AND AT LEAST ONE SIDE OF WHICH IS SEPARABLE THEREFROM, A BACKING PANEL EXTENDING ACROSS THE SPACE BETWEEN THE MEMBERS OF SAID BORDER FRAME AND SECURED TO SAID BORDER FRAME, SAID BORDER FRAME AND SAID BACKING PANEL FORMING AN INTEGRAL DISPLAY CARD UNIT A DISPLAY CARD SUPPORT CHANNEL INTERIORLY OF THE LOWER ONE OF SAID CHANNEL MEMBERS, SAID BACKING PANEL HAVING A CENTRAL PORTION DISPLACED FROM THE PLANE OF THE EDGES THEREOF AND PROTRUDING INTO THE SPACE BETWEEN THE MEMBERS OF SAID BORDER FRAME FOR FRICTIONAL ENGAGEMENT OF THE BACK SURFACE OF A DISPLAY CARD SUPPORTED IN SAID CHANNEL WITH ITS EDGES IN SAID CHANNEL MEMBERS, SUPPORT MEMBERS MOUNTED ON SUCH VERTICAL SURFACE, EACH OF SAID SUPPORT MEMBERS CONSISTIG OF A VERTICALLY EXTENDING BRACKET HAVING FORWARDLY EXTENDING, GENERALLY PARALLEL ARMS AT ITS ENDS, MOUNTING MEMBERS SECURED ON THE BACK SIDE OF SAID DISPLAY CARD UNIT, EACH OF SAID MOUNTING MEMBERS CONSISTING OF A VERTICALLY EXTENDING BRACKET HAVING REARWARDLY EXTENDING, GENERALLY PARALLEL ARMS AT ITS ENDS, THE ARMS OF SAID BRACKETS BEING EQUALLY SPACED AND ENGAGEABLE AS AND UPPER PAIR AND A LOWER PAIR AND DISENGAGEABLE MEANS COMPRISING A PILOT PIN AND HOLE ON ONE ENGAGEABLE PAIR OF SAID ARMS AND THREADED MEANS ON THE OTHER PAIR OF SAID ARMS FOR RELEASABLY SECURING SAID MEMBERS TOGETHER AND FOR SUPPORTING SAID DISPLAY CARD UNIT OUTWARDLY OF SUCH VERTICAL SURFACE.