Building structure

Claim 1

A building structure comprising a first elongated and essentially rigid rail comprising a web and integrally fromed therewith inner and outer flanges projecting transversely from said web, a second elongated and essentially rigid rail generally parallel to said first rail, mutually spaced apart therefrom in a first principal plane containing said web of said first rail and in turn comprising: a first web disposed in said first principal plane; first inner and outer flanges integrally formed with said first web and projecting transversely therefrom; a second web integrally formed with said first web and disposed in a second principal plane angularly disposed with respect to said first principal plane; and second inner and outer flanges integrally formed with said second web and projecting transversely therefrom; a third elongate and essentially rigid rail generally parallel to said second rail, spaced apart therefrom in said second principal plane and in turn comprising a web disposed in said second principal plane and integrally formed therewith inner and outer flanges projecting transversely from said web; a first pair of elongated, mutually spaced and essentially rigid cross members each comprising a base and extending between said first and second rails generally in said first principal plane and being slidably received in rectangular openings provided in said inner flange of said first rail and in said first inner flange of said second rail and terminally abutting said outer flange of said first rail and said first outer flange of said second rail so as essentially to prevent movement of said first and second rails toward each other and movement of the ends of said cross members of said first pair both in the longitudinal direction of said first and second rails and transversely relative to said first principal plane; a second pair of elongated, mutually spaced and essentially rigid cross members each comprising a base and extending between said second and third rails generally in said second principal plane and being slidably received in openings provided in said inner flange of said third rail and in said second inner flange of said second rail and terminally abutting said outer flange of said third rail and said second outer flange of said second and third rails toward each other and movement of the ends of said cross members of said second pair both in the longitudinal direction of said second and third rails and transversely relative to said second principal plane; two generally diagonally extending bracing members mutually angularly disposed and terminally interconnecting said first and second rails to maintain those rails and said first pair of cross members in interfitting assembled configuration in a predetermined angular orientation; two generally diagonally extending bracing members mutually angularly disposed and terminally interconnecting said second and third rails to maintain those rails and said second pair of cross members in interfitting assembled configuration in a predetermined angular orientation; each said bracing member including a length-adjusting mechanism whereby, after assembly of said rails, said cross members and said bracing members, the lengths of said bracing members can be reduced by operation of said length-adjusting mechanism for adjusting and maintaining said rails and cross members in said predetermined angular orientations; each said cross member also comprising a flange extending from said base thereof relative to a respective one of said first and second principal planes, and terminally received in aligned notches provided in longitudinally extending lips provided on respective ones of said rails and projecting inwardly of said outer flanges of respective ones of said rails so as to restrict relative pivotal movement of said rails and said cross members in respective ones of said first and second principal planes prior to connection of said bracing members to sail rails.