US Patent 8056294 Concealed suspension ceiling with downward removable panels

A suspended ceiling system comprising metal grid members and rectangular composite acoustical panels, the panels having edges at their peripheries, the grid members having a cross section generally like an inverted T such that they provide oppositely extending flanges adapted to support the panels at their edges, a resilient element at a juncture between a support on the grid member flanges and at least one edge of each panel, the resilient element being arranged to temporarily deflect to permit a panel to be raised from below the grid member into an installed position and to extend itself to hold such panel in position on the grid.