Panel for inclusion in a unit to be installed in a building opening

Claim 1

IN A PANEL STRUCTURE FOR FITTING WITHIN AND CLOSING A FRAME ADAPTED TO BE SET IN A WALL OPENING, FIRST AND SECOND PANES OF REGULAR GEOMETRICAL CONTOUR, A SPACER FRAME HAVING A BOTTOM WALL AND PARALLEL SPACED PLANAR SIDE WALLS EXTENDING OUTWARDLY FROM AND INTEGRAL WITH THE RESPECTIVE EDGES OF SAID BOTTOM WALL, SAID SPACER FRAME BEING INTERPOSED BETWEEN SAID PANES TO SPACE THE PANES AND TO DEFINE THEREWITH A CLOSED SPACE, A MULLION WITHIN SAID CLOSED SPACE AND COMPRISING AT LEAST ONE ELONGATED MUNTIN ELEMENT HAVING ITS ENDS ABUTTING SAID BOTTOM WALL AT POINTS SPACED THEREALONG, AND MEANS PROJECTING INWARDLY FROM SAID BOTTOM WALL IN FIXED RELATION THEREWITH, AT EACH POINT OF CONTACT OF SAID MUNTIN ELEMENT WITH SAID BOTTOM WALL AND IN CONTACT WITH LATERALLY OPPOSED SURFACES OF SAID MUNTIN ELEMENT, TO MAINTAIN SAID MULLION FIXED WITH RESPECT TO SAID FRAME.