Structural unit for wooden roofs has two rafters with projections at feet to engage in recesses of roof beam as rafters unfold about swivel joint

摘要

The unit has two rafters (10, 12) each with projections (24, 26) at the feet (20, 22) and a roof beam (2) with recesses (16, 18) at the end for the projections. Each rafter is swivel connected to one of the clamps by a joint (8, 14) and the distance of the joint from the recess in the roof beam equals the distance of the joint from the projection so that when the rafters are unfolded and connected to the ridge the projections engage in the recesses of the beam.