Hood for use on Avionic line replaceable unit

• US 5,725,622 A
• Filed: 09/04/1996
• Issued: 03/10/1998
• Est. Priority Date: 09/04/1996
• Status: Expired due to Fees

• Current Assignee: Electronic Cable Specialists, Inc. (Carlisle Cos., Inc.)
• Original Assignee: Electronic Cable Specialists, Inc. (Carlisle Cos., Inc.)
• Inventors: Presberg, Laurence J., Whitson, Frederick A., Mathur, Balaji J., Heckel, Laurence J.
• Primary Examiner(s): BUSHEY, CHARLES S
• Application Number:
  US08/706,518
• Time in Patent Office: 552 Days
• Field of Search: 55/322, 55/325, 55/328, 55/332, 55/385.1, 55/385.2, 55/385.4, 55/385.6, 55/385.7, 55/383, 55/493, 55/502, 361/695, 454/76, 454/141, 454/158, 454/184
• US Class Current: 55/385.4
• CPC Class Codes: B01D 46/00 Filters or filtering processes specially modified for separating dispersed particles from gases or vapours filtering elements B01D24/00-B01D35/00; filtering material B01D39/00; their regeneration outside the filters B01D41/00
• CPC Class Codes: H05K 7/1412 hold down mechanisms, e.g. avionic racks

Abstract

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.

Claims

1. A hood adapted for mounting to an avionic box for directing the flow of coolant air over an end wall, a top wall extending longitudinally from the end wall, over opposite sidewalls that extend longitudinally from the end wall and have laterally spaced apart outside surfaces, over at least one of the sidewalls having inlets for air to enter the box for exiting from its bottom, the hood comprising:

an end wall having margins defining an air inlet opening that is to be positioned adjacent to the end wall of the avionic box when the hood is mounted to the box,

a top wall extending longitudinally from said end wall of the hood for being supported in spaced relationship with the top wall of an avionic box to define a longitudinally extending coolant air passageway cooperatively with the box,

said hood having longitudinally extending sidewalls depending unitarily from said top wall terminating in edges, and

said sidewalls having corresponding inside surfaces spaced apart from each other by a greater distance than the space between the outside surfaces of the avionic box on which the hood is to be mounted for defining coolant air passageways extending longitudinally along opposite sidewalls of the hood and over the position of air inlet holes in the walls of the box,

gasket members disposed on said edges of the sidewalls of the hood to prevent coolant air from leaking to the atmosphere from said passageways along the sidewalls,

means including a gasket fastened on said 35 top of the hood remotely from said end wall of the hood to support said top of the hood on an avionic box and effect a seal between said top of the hood and the top of the box on which the hood is mounted and to maintain said top of the hood spaced from the top of the avionic box on which the hood is mounted,

a door hingedly mounted to said end wall of the hood for cooperating with said air inlet opening in said end wall of the hood, said door having a wall with louvers for infeed of coolant air, said door defining a recess for containing an exchangeable filter element that is disposed sealingly to said margins of said inlet opening when said door is closed.

2. A hood according to claim 1, including a spacer member fixed to said end wall of the hood for abutting an avionic box on which the hood can be mounted to maintain a plenum space between said end wall of the hood and end walls of the avionic box, and a gasket on said member for effecting a seal between said member and an avionic box on which the hood is installed.

3. A hood according to claim 2 wherein at an end of each sidewall remotely from said end wall of the hood a flange extends integrally from each sidewall, said flanges are planar and at right angles to the sidewall from which they extend,

a bar member extends across the space between said sidewalls and has a side that interfaces with said top wall of the hood and a gasket on a side opposite of said side for sealingly interfacing with a top wall of an avionic box on which the hood is installed, and

a clamping member mounted to each flange and operative to apply a force to an avionic box to which the hood is installed for securing said hood to an avionic box and for pressing said gasket on said spacer member against said box.

4. A hood according to claim 1 wherein said door has wing portions extending laterally in opposite direction spaced from where said door is hingedly mounted and said wing positions interface with said margins that define said air inlet opening in said end wall of the hood,

door latching means including a bifurcated latching element mounted for sliding on said wings, respectively, and

headed pins fixedly mounted on said margins for said latching elements to slide under the heads of the headed pins to lock the door to said end wall of the hood.

5. A hood according to claim 1 wherein the width of said passageways between each sidewall of said hood and the sidewalls of an avionic box on which the hood is mounted is at least about 0.0625 inch (1.6 mm) and the depth of said passageway between the top wall of the hood and the top wall of an avionic box on which the hood is mounted is about 0.5 inch (12.7 mm).

6. A hood according to claim 3 including a plurality of posts composed of elastic material fastened to said top wall of said hood for bearing on the top wall of an avionic box on which said hood is installed to support the hood.

7. A hood adapted for mounting to an avionic line replaceable unit (LRU) box for directing coolant air streams into and out of the LRU, LRU having an end wall containing air inlet holes, a top wall having an outside top surface, opposite side walls having spaced apart outside surfaces and containing air inlet holes, and a bottom wall having an air exit opening for being coupled to an evacuable plenum for drawing coolant air through said LRU, said hood comprising:

a longitudinally extending top wall having an inside surface, a nominally vertical end wall depending from said top wall and having margins defining an air inlet opening, and opposite side walls depending nominally vertically and unitarily from said top wall, said side walls having corresponding inside surfaces spaced apart from each other by a distance greater than said distance between said outside surfaces of sidewalls of a LRU on which the hood is to be mounted,

means for mounting said hood to an LRU, said hood when mounted to an LRU has said inside surfaces of said side walls of the hood disposed over said air inlet holes in the sidewalls of the LRU and spaced from said outside surfaces of the sidewalls of the LRU to thereby define air conducting passageways between said sidewalls of the hood and the sidewalls of the LRU, said inside surface of said top of the hood is spaced from said outside surface of the top wall of the LRU when said hood is mounted to an LRU to define an inlet-air conducting passageway that communicates with said passageways between said sidewalls of the LRU and the hood, said end wall of the hood is spaced from the end wall of the LRU when the hood is mounted to an LRU to define a distribution plenum between said end walls of the hood and the LRU, respectively, bounded by said sidewalls of the hood, and a member disposed between said end walls of the hood for enclosing said distribution plenum when the hood is mounted to an LRU, said sidewalls, top wall and end walls of the hood all having edge margins and there are pliable gasket elements at said edge margins for sealing said passageways defined by said sidewalls of said hood when said hood is mounted to an LRU, and

an air filter element and means for holding said filter element over said air inlet opening in said end wall of the hood for air to pass through said filter element into said distribution plenum.

8. A hood according to claim 7 wherein:

said means for holding said filter element over said air inlet opening in the end wall of said hood is a door member hingedly attached to said hood and adapted for swinging toward and away from said air inlet opening,

said door member having one side that faces toward said end wall of the hood when the door is closed and having a side opposite of said one side, containing a plurality of air inlet holes,

said one side of said door member having means defining a recess for retaining said filter element such that when said door is closed the door presses said filter element sealingly to said end wall of the hood.

9. A hood according to claim 7 including latching devices operable to lock said door member to said end wall of the hood.

10. A hood according to claim 7 wherein areas of said door member are deflected away from said side opposite of the door member in proximity with said air inlet holes in the door member to provide a louvre over each hole in the door member.

11. A hood according to claim 7 wherein the width of said air conducting passageways defined between said sidewalls of the LRU on which the hood is mounted and the sidewalls of the hood is at least about 0.0625 inch.

12. A hood according to claim 7 wherein the width of said air conducting passageway defined between said top of the hood and the top of said LRU on which the hood is mounted is about 0.5 inch.