초록 ▼

A filter assembly for a line replaceable unit (LRU) uses a four-walled frame to define a plenum which mounts in sealing relationship with the top surface of an LRU. The frame interfaces with the LRU through a gasket and there is a gasket on a rim extending from the LRU walls on which the filter elem

A filter assembly for a line replaceable unit (LRU) uses a four-walled frame to define a plenum which mounts in sealing relationship with the top surface of an LRU. The frame interfaces with the LRU through a gasket and there is a gasket on a rim extending from the LRU walls on which the filter element is superimposed such that the filter element, the walls of the frame and the perforated top surface of the LRU define a plenum. When the frame is integral to or mounted to the avionic tray that supports the LRU, the filter element is mounted to the top of the frame and the hold-down cover compresses the filter element to the frame such that intervening gaskets effect a seal between the parts so that all air entering the LRU under the influence of negative pressure applied to holes in the bottom of the LRU must pass through the large area filter element. The cover is hinged so that it can be unlocked from the avionic tray and swung to a position wherein the filter element is accessible for being grasped, removed and replaced with a clean element without requiring withdrawal of the LRU from the avionic tray.

대표청구항 ▼

A filter assembly for prefiltering coolant air that enters an avionic line replaceable unit (LRU) box through holes in the top surface of the box and exits through at least one hole in the bottom of the box which is coupled in airflow communication with a negative pressure plenum when said LRU box i

A filter assembly for prefiltering coolant air that enters an avionic line replaceable unit (LRU) box through holes in the top surface of the box and exits through at least one hole in the bottom of the box which is coupled in airflow communication with a negative pressure plenum when said LRU box is in an avionic tray, said avionic tray providing support members arranged, respectively, proximate to opposite ends of said top surface of the box, said filter assembly comprising: a frame comprised of side and end wall members that have upper and lower rims, said wall members arranged to define a plenum opening for passage of coolant air into the LRU and the frame is adapted for being positioned with the wall members superimposed on the margins of said top surface of the LRU box with sealing means between said frame and the top surface, a filter element supported in said frame for spanning across said opening at a distance from the LRU box top surface such that the filter element, the top surface and the walls of the frame define a plenum under the filter element, a hold-down cover for being superimposed in compressive relation on said filter element and having an open area for filtered air to flow into the plenum, and means for releasably attaching said hold-down cover to said support members provided by the tray such that when said hold-down cover is released said filter element is accessible without removing said LRU box from said avionic tray.