Electronic Cable Specialists, Inc.

Frederick A Whitson

William K Siebert

Kenneth B Raihala

Laurence J Presberg

Balaji J Mathur

Carlos Assef

Laurence J Heckel

A hood preferably made of sheet metal for directing coolant air in air inlet holes in the walls of an avionic box containing electrical components such as an avionic line replaceable unit (LRU). The hood has a top wall with opposite side walls and an end wall that depends unitarily from the top wall. The hood fits onto the box with the top wall and side walls of the hood spaced from the corresponding top wall and side walls, respectively of the avionic box when the hood is mounted on the box to thereby define coolant air conducting passageways contiguous with the box. The end wall of the hood that depends from the top wall is spaced from the end wall of the box when the hood is mounted to the box to define an air distribution plenum that is in communication with the passageways at the sides and top of the box so coolant air is directed through holes in the end wall if any holes are used in the end wall and side walls of the box. The end wall of the hood has an opening for being covered by a door. The door has a recess for containing a filter element for holding the element over the door in the hood end wall. The door is pierced to create a plurality of air inlet openings with a louvre over each opening to shed downwardly dripping liquid contaminants so the liquid does not flow into the filter element.

Hood for use on Avionic line replaceable unit

A filter assembly for a coolant air stream flowing through an LRU box has a base frame with a large opening superimposed on the perforated top surface of the box. A filter element is superimposed over the opening and a cover having a large opening is hinged to the base frame and latched thereto with its opening aligned with the other opening. The filter assembly is clamped by means of a harness to the LRU box with a clamping band that wraps around one end of the LRU box and one end portion of the base frame simultaneously. Spring tensioned cable sections attach to the band and extend diagonally along the sides of the LRU box and then through eyelets on the opposite end portion of the base frame so the cable develops a vertical component of force for clamping the assembly to the LRU box.

Filter for mounting on an avionic line replaceable unit

An avionic tray has a base plate for supporting a line replaceable unit (LRU) and a plenum beneath and substantially coextensive in length with the base plate to provide for discharge of coolant air from the plenum into the LRU. The base plate has an opening leading to the plenum and the cylindrical casing of a motor driven fan is coupled to the base over the hole for air from the fan to be discharged into the plenum. The outlet end of a ram tube is coupled coaxially with the fan casing to increase the volume that would be delivered without the ram tube. The inlet end of the ram tube is preferably cut at an angle relative to a plane to which the axis of the tube is perpendicular so the inlet is elliptical rather than circular. The fan is mounted to a special transition adapter in some cases. The adapter is configured to provide a clearance space for cables that run out of the rear side of a connector block on whose front side connector prongs on the LRU are inserted. The input opening of the adapter is circular and its output opening is rectangular. Both openings have the same cross-sectional area.

Avionic instrument tray cooling system

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.

Growing community of inventors

Oconomowoc, WI, United States of America

Frederick A Whitson