a raised position so that hook 32 can clear the bottom of the slot shoulder 28 prevents further movement horizontally into the slot 48 clip 20 is then forced downward as shown by the arrow in fig1 until shoulder 28 can clear the top of slot 48 and recess 33 engages the bottom edge of slot 28 flange 52 will engage flange 53 on main beam 51 clip 20 is shown fully seated in slot 48 of main beam 51 in fig1 and 12 the first lock between the main beam 51 and cross beam 47 is completed at this position the opposing connector clip 20 u2032 is brought into engagement with the connector clip 20 by being inserted in a hooking action from the opposing side it is this hooking action that is critical to the assembly since it permits the ridge 36 u2032 of 20 u2032 to by pass the ridge 36 of 20 during insertion without interference and then have gaps 37 and 38 in the ridge 36 interlock with the gaps 37 u2032 and 38 u2032 in the ridge 36 u2032 in a relatively vertical movement it is this movement which simultaneously completes the first and second locks when interlocked the relatively straight rearwardly extending edges 42 and 43 in gaps 37 and 38 abut relatively straight rearwardly extending front edges 42 u2032 and 43 u2032 in gaps 37 u2032 and 38 u2032 thus resisting any tension forces that.