Safety closure for equipment housing - seals ventilation outlet to prevent discharge of toxic gases using steel flap with fireproof material on inner side

摘要

A high power electrical transformer is located in a concrete housing (11) formed with a ventilation shut (12) normally open to the atmosphere. A cover is formed with a steel plate (16) and fireproof material (22). The lower is hinged (18) on one side and is normally held open by a counter balance weight (33) with a cord (31) passing over a pulley wheel. (21). If a short circuit causes the internal temp. to rise to a critical level, the cord disintegrates and the cover swings closed to seal against a slip plage (30. USE - In case of fire, normally ventilated housing is closed off such that flames smoke or other gases cannot escape.