Sign with wind balanced front sheet

Abstract From the Canadian patent

An internally illuminated sign structure comprising a housing enclosing a plurality of lamps and having an open front in which is supported a windbalanced sheet of translucent film bearing the sign message. The housing has passages communicating with the laminar air flow region about the housing to the interior to allow air to enter the structure, which air develops a pressure equal to that developed by the wind component striking the face of the film to afford a static balance on the front face of the film. The passage to the interior of the housing has a total cross-sectional area at the plane of the film of at least 5 times the combined area of any other openings in the housing which do …