Chassis containing electronic components with fire containment trap door

Abstract

A fire containment and air flow control mechanism for a device or chassis housing electronic components. The electronic components generate heat during operation of the device. An aperture in the housing permits warm air generated within the chassis to escape into the environment to cool the circuit board or card. A trap door is provided for the aperture for purposes of fire containment. Normally, the trap door is open, allowing the warm air to escape through the aperture. The trap door is moveable relative to the housing between a first position, in which the trap door does not cover the aperture, and a second position, in which the trap door substantially obstructs the aperture. A temperature sensitive material, such as a nylon or other polymeric filament that melts when subject to sufficient heat or flame, is operatively connected to the trap door. The temperature sensitive material is transformed, e.g., by melting, upon exposure to sufficient heat or flame within the device so as to cause the trap door to move to the second position relative to the aperture. In this position, the trap door substantially prevents migration of any flame present within the device through the aperture. For example, the trap door may be held away from the aperture by the filament, and when the filament melts the door swings by gravity or drops into a closed condition relative to the aperture.