Building structure

Claim 1

BUILDING WALL STRUCTURE COMPRISING A HEAD MEMBER AND A SILL MEMBER SECURED TO THE TOP AND BOTTOM OF AN OPENING IN A BUILDING WALL RESPECTIVELY, A WALL UNIT ADAPTED TO FIT WITHIN THE OPENING IN THE BUILDING WALL AND EXTENDING BETWEEN SAID HEAD AND SILL MEMBERS, SAID SILL MEMBER HAVING A WEB AND SIDE WALLS, SAID SIDE WALLS TERMINATING IN FLANGES EXTENDING TOWARD EACH OTHER AND DEFINING A CHANNEL OPENING, A CLIP HAVING OPPOSITELY EXTENDING FLANGES POSITIONED WITHIN SAID CHANNEL, THE CLIP FLANGES OVERLAPPING THE CHANNEL FLANGES, AN ANGLE BAR SECURED TO SAID WALL UNIT, AND MEANS RELEASABLY DRAWING SAID CLIP TIGHTLY AGAINST SAID ANGLE BAR, THE CLIP FLANGES BEING OFFSET WITH RESPECT TO THE REST OF THE CLIP TO PROVIDE SLIDING CLEARANCE BETWEEN THE CHANNEL FLANGES AND THE CLIP FLANGES WITH THE CLIP HELD TIGHTLY AGAINST SAID ANGLE BAR ALLOWING MOVEMENT OF THE WALL UNIT ALONG THE HEAD AND SILL MEMBERS IN THE PLANE OF THE BUILDING OPENING FOR POSITIONING THE WALL UNIT DURING INSTALLATION THEREOF, THE FLANGES OF SAID CLIP BEING OPERABLE IN CONJUNCTION WITH THE FLANGES OF SAID CHANNEL TO PREVENT PIVOTAL MOVEMENT OF THE WALL UNIT ABOUT SAID SILL MEMBER IN A DIRECTION INWARDLY OR OUTWARDLY OF THE BUILDING WALL IN RESPONSE TO PRESSURES DUE TO WIND AND ATMOSPHERIC CONDITIONS.