Tensioned frame structure

Claim 1

IN A TENSION BOLTED KNOCK-DOWN FRAME STRUCTURE A PAIR OF ELONGATED CHANNEL FRAME ELEMENTS OF SHEET METAL ARRANGED SUBSTANTIALLY AT RIGHT ANGLES TO EACH OTHER, SAID CHANNEL FRAME ELEMENTS HAVING THEIR CHANNEL SECTIONS OPENING INWARDLY, AN END PORTION ON ONE OF SAID FRAME ELEMENTS EXTENDING AT RIGHT ANGLES THERETO AND NESTED OVER ONE END OF THE OTHER FRAME ELEMENT, AN ANGULARLY DISPOSED INTERMEDIATE PORTION CONNECTING SAID END PORTION TO SAID ONE FRAME ELEMENT, A LEG MEMBER FORMED OF SHEET METAL WITH FLAT EDGE FLANGES LYING SUBSTANTIALLY PERPENDICULAR TO EACH OTHER AND CONNECTED BY AN ANGULARLY DISPOSED INTERMEDIATE WALL TO SUBSTANTIALLY CONFORM TO THE ANGULAR FORMATION OF SAID ONE FRAME ELEMENT AND LIE IN SUBSTANTIAL FACE TO FACE CONTACT THEREWITH, SAID FLAT EDGE FLANGES BEING NORMALLY INCLINED SLIGHTLY AWAY FROM THE UNDERLYING ONE FRAME ELEMENT, SPACED NUTS SECURED FIRMLY TO THE WEBS OF THE CHANNEL FRAME ELEMENTS AND UNDERLYING THE EDGE FLANGES OF THE LEG MEMBER, SAID EDGE FLANGES AND SAID OVERLYING END PORTION OF SAID ONE FRAME ELEMENT HAVING SPACED APERTURES THEREIN EACH IN REGISTERING ALIGNMENT WITH A NUT, AND BOLTS EXTENDED THROUGH SAID APERTURES AND ENGAGED IN THE RESPECTIVE NUTS TO DRAW THE FLAT EDGE FLANGES TIGHTLY AGAINST THE UNDERLYING FRAME ELEMENT TO SECURE THE PARTS TOGETHER UNDER TENSION.