according to the embodiment shown in fig7 element 42 includes formations 43 and 44 and element 41 includes formations 45 and 46 these mate with corresponding top and bottom plate members according to the arrangements previously described allowing longitudinal adjustment relative to the plates in addition to vertical adjustment in the direction of arrow 47 during the cold forming of element 42 flanges 48 and 49 are crushed at regions 50 and 51 as formations 43 and 44 are introduced into element 42 likewise flanges 52 and 53 are crushed in the regions of 54 and 55 as formations 45 and 46 are introduced into element 41 fig8 shows a telescopic stud element 60 according to an alternative embodiment stud 60 comprises elements 61 and 62 which are capable of telescopic adjustment in the direction of the arrow 63 stud 60 further comprises an element 62 formations 64 and 65 which engage corresponding formations in a plate in a manner previously described likewise element 61 comprises formations 66 and 67 which will engage a bottom plate as previously described fig9 shows a section of the frame of fig4 defined by line x x and include junction 70 and end junction 71 junction 71 is formed by mating of telescopic stud 72 and top plate 73 as telescopic stud 72 comprises telescopic elements 74 and 75 stud 72 may extend to increase the local height of the frame likewise intermediate stud 76 which comprises elements 77 and 78 may also extend in which case that portion of the frame.