of 34 t 34 connector members 30 which are parallel to and offset within the parallel axes of the floor rails 18 an additional tubular stub 32 extends forwardly from the 34 t 34 connector members 30 an adjustable leveler member 34 is placed under each of the 34 t 34 connector members 26 30 and the footpad 24 in addition a leveler member 34 is placed under a set of forward legs 36 of the front section 14 the forward ends of the tubular stubs 32 are joined to the legs 36 adjacent the leveler members 34 the leveler members 34 preferably include a threaded stud and a rotatable foot member which engages the threaded stud as described in the previously referred to co pending application the front section 14 will now be described with particular reference to fig1 and 2 the pair of front legs 36 and a pair of rear legs 38 support a set of substantially horizontal hand rails 40 an upper cross bar 42 and a lower cross bar 44 span between the front legs 36 for providing structural rigidity to the space frame in addition a pair of side bars 46 extend between the front legs 36 and the rear legs 38 as previously mentioned the front legs 36 include leveler members 34 for contact with the floor surface 22 the rear legs 38 however terminate within a neck opening or socket 48 of the 34 t 34 connector members 26 a center frame 50 includes a set of spaced longitudinal leg members 60 which are slidably.