US Patent 9121428 Assembly providing a connection that is self tightening with temperature

The invention relates to an assembly comprising first and second parts made of composite material and held against each other by at least one fastener system comprising a rivet having a flat head from which there extends a shank having an enlarged end, and a washer co-operating with the enlarged end of the shank of the rivet, the head of the rivet bearing against a countersink formed in the first part, the washer bearing against the second part. On its face remote from its face bearing against the second part, the washer presents a portion of conical shape. The washer also has a central countersink with the enlarged end of the shank of the rivet pressing thereagainst.