Assembly kit for erecting demountable frame structures

Claim 1

An assembly kit, for erecting demountable frame structures, comprising at least one primary sub-frame, at least one secondary sub-frame, connectable to said primary frame, and at least one extension sub-frame connectable to said primary frame and to said secondary frame, in which: each primary sub-frame comprises: two identical tubular side members which each have opposite ends, intermediate portions respectively spaced a first distance apart, and end portions extending to said opposite ends from said intermediate portions, two equal length cross members extending perpendicularly between the side members from said intermediate portions of the side members which are spaced a first distance apart and respectively spaced by a second distance from said opposite ends of the side members, and four tubular legs, of equal length and having a free end and the same cross-section as the side members, extending from said intermediate portions of the side members to one side of a plane defined by the axes of the side members and the cross members with the axes of the legs extending perpendicular to the axes of adjacent cross members and defining planes respectively passing through the axes of the cross members and being equally inclined to the adjacent end portions of the side members; each secondary sub-frame comprises: two identical tubular "L"-shaped side members which each have an internal cross-section providing a sliding fit over the external cross-section of the end portions of the opposite ends of the side members and the legs of each primary sub-frame, first and second arms having lengths respectively equal to a third distance greater than said second distance and to said second distance, and a junction between said first and second arms, each first arm having a free end and an intermediate portion spaced from said free end by a distance equal to said second distance, a first cross member extending perpendicularly between the first arms of the "L"-shaped members from said intermediate portions of the first arms of the "L"-shaped side members respectively spaced from said free ends of said first arms by a distance equal to said second distance, and a second cross member extending perpendicularly between the junctions of the two arms of both "L"-shaped side members so that said junctions both engage the same side of the second cross member at opposite ends of the second cross member; and each extension sub-frame comprises: two identical tubular side members, and two cross members both equal in length to the cross members of each primary sub-frame and extending perpendicularly from the side members of the extension sub-frame from said intermediate portions of the side members of the extension sub-frame respectively spaced by said second distance from said opposite ends of the side members of the extension sub-frame, the side members of the extension sub-frame respectively comprising long portions of the same external cross-section as the side members and legs of each primary sub-frame and adjacent short portions each having a free end, a length equal to said second distance and an internal cross-section which is a sliding fit over the external cross-sections of the side members and legs of each primary sub-frame.