A seismic expansion joint cover assembly installed at an expansion gap between a first structural member on one side of a gap and a second structural member on the opposite side of the gap including a cover panel bridging the gap having at least one connector joining one edge of the cover panel to the first structural component to allow movement of the cover panel. The expansion joint cover assembly includes at least one slide support, which attaches to the second structural member, and which includes a track having a lift component located on the track to lift the cover panel. The expansion joint cover assembly also includes a rider assembly for engaging with the track of the slide support. One or more spring assemblies are attached to the second structural member and the cover panel. The expansion joint cover assembly is mechanically latched when the system is in the normal service position, but has the capability of becoming unlatched in response to large displacements.