Self-closing single-sided accordion fire door

An accordion fire door comprising

• an accordion member comprising a plurality of panels each having a first vertical edge, a second vertical edge, a top horizontal edge, and a bottom horizontal edge, the first vertical edge of each panel being provided with a female hook member having a hook shank formed at an acute angle to said panel and a female hook portion formed on said hook shank away from said panel, said female hook portion having a semicircular cross-section with an inside radius, the second vertical edge being provided with a male hook member having a hook shank formed at an acute angle to said panel and a male hook portion which is received in the female hook portion of an adjacent one of said panels to form a pivotable connection between adjacent panels, said male hook portion being formed on said hook shank toward said panel, said male hook portion having a semicircular cross-section with an outside radius which is slightly smaller than said inside radius of said female hook portion, and
• a plurality of guide assemblies attached to the top edges of respective panels for suspending said panels from a guide track and for guiding said panels from an open position to a closed position wherein adjacent said panels extend transversely to each other in a zig-zag pattern at an obtuse angle, one of said guide assemblies being fixed to every other one of said panels substantially centrally between the vertical edges, said hook members being designed so that a predetermined obtuse angle between adjacent said panels cannot be exceeded, said predetermined obtuse angle corresponding to the sum of the acute angles of said male and female hook shanks with respect to said panels.

An accordion fire door installation comprising

• an overhead guide track,
• an accordion member comprising a plurality of panels each having a first vertical edge, a second vertical edge, a top horizontal edge, and a bottom horizontal edge, the first vertical edge of each panel being pivotably connected to the second vertical edge of an adjacent one of said panels, wherein said first vertical edge of each said panel has a female hook member having a hook shank formed at an acute angle to said panel and a female hook portion formed on said hook shank away from said panel, said female hook portion having a semicircular cross-section with an inside radius, and said second vertical edge has a male hook member having a hook shank formed at an acute angle to said panel and a male hook portion which is received in said female hook portion of an adjacent panel to pivotably connect said first and second vertical edges of adjacent panels, said male hook portion being formed on said hook shank toward said panel, said male hook portion having a semicircular cross-section with an outside radius which is slightly smaller than said inside radius of said female hook portion, and wherein adjacent said panels form an obtuse angle to each other when said accordion member is in the closed position, said hook portions being designed so that a predetermined obtuse angle between adjacent said panels cannot be exceeded, said predetermined obtuse angle corresponding to the sum of the acute angles of said male and female hook shanks with respect to said panels, and
• a plurality of guide assemblies attached to the top edges of respective panels for suspending said panels from said guide track and for guiding said panels from an open position to a closed position wherein said panels extend transversely to each other in a zig-zag pattern, one of said guide assemblies being fixed to every other one of said panels substantially centrally between the vertical edges.