Fireproof pressure relief assembly

Patent metadata

Field	Value
Publication number	US-11008089-B2
Application number	US-201816169146-A
Country	US
Kind code	B2
Filing date	Oct 24, 2018
Priority date	Oct 24, 2018
Publication date	May 18, 2021
Grant date	May 18, 2021

Abstract

A pressure relief assembly (24) includes an aircraft engine cowl (26) having radially outer and inner skins (28,30) having an opening. A door frame (32) is joined around the perimeter of the opening and defines a door seat (34) surrounding a central portal (36). A pressure relief door (38) is joined to the cowl (26) to cover the portal (36). The door (38) has inner and outer surfaces (40,42) terminating in a perimeter rim (44), with the inner surface (40) of the rim (44) overlapping the door seat (34) to define a primary seal (46) with the door stowed closed. A fireproof secondary seal (48) bridges the door inner surface (40) and frame (32) around the inner perimeter of the primary seal (46) to pre-seal flow to the primary seal (46).

First claim

Accordingly, what is desired to be secured by Letters Patent of the United States is the invention as defined and differentiated in the following claims in which we claim:

1. A pressure relief assembly ( 24 ) comprising:
an aircraft engine cowl ( 26 ) including radially outer and inner skins ( 28 , 30 ) having an opening therethrough;
a door frame ( 32 ) fixedly joined around the perimeter of said opening and extending laterally therefrom to define a door seat ( 34 ) surrounding a central portal ( 36 ) and facing radially outwardly;
a pressure relief door ( 38 ) pivotally joined to said cowl ( 26 ) for being deployed outwardly from a stowed closed position covering said portal ( 36 ) to a deployed open position uncovering said portal ( 36 );
said door ( 38 ) having radially opposite inner and outer surfaces ( 40 , 42 ) terminating in a perimeter rim ( 44 ), with said inner surface of said rim ( 44 ) overlapping said door seat ( 34 ) to define a primary seal ( 46 ) in said door stowed position; and
a fireproof secondary seal ( 48 ) bridging said door inner surface ( 40 ) and said frame ( 32 ) around the inner perimeter of said primary seal ( 46 ) to pre-seal flow to said primary seal ( 46 ).

2. An assembly according to claim 1 further comprising:
a hinge ( 50 ) pivotally joining said door ( 38 ) to said cowl ( 26 );
a pressure relief latch ( 52 ) latching closed said door ( 38 ) in said stowed position and having a predetermined release load at which said latch ( 52 ) releases said door ( 38 ) to permit deployment thereof;
said door seat ( 34 ) and said door rim ( 44 ) being in direct contact to define a sealed lap joint thereat; and
said secondary seal ( 48 ) including an inner perimeter terminating closely adjacent to said door frame ( 32 ) to maximize surface area of said door inner surface ( 40 ) uncovered by said secondary seal ( 48 ) to in turn maximize pressure load against said door ( 38 ) for reaching said predetermined release load of said latch ( 52 ).

3. An assembly according to claim 2 wherein:
said door outer surface ( 42 ) is aerodynamically smooth and disposed aerodynamically flush with said cowl outer skin ( 28 ) in said stowed position;
said door ( 38 ) further includes a structurally thick central panel ( 54 ) from which said door rim ( 44 ) extends laterally for providing a thin rim ( 44 ) surrounding said door central panel ( 54 ); and
said secondary seal ( 48 ) terminates outboard of said central panel ( 54 ) to maximize said uncovered surface area.

4. An assembly according to claim 3 wherein:
said cowl ( 26 ) and door ( 38 ) are circumferentially arcuate, and said door frame ( 32 ) varies in curvature around the circumference thereof to locally match said cowl ( 26 ) and door ( 38 ); and
said secondary seal ( 48 ) includes an inner sealing lip ( 56 ) extending in a cantilever laterally inwardly from said door frame ( 32 ) and varying in flexibility around said inner perimeter thereof for effecting an unwrinkled compression seal against said door rim ( 44 ).

5. An assembly according to claim 4 wherein:
said cantilever inner lip ( 56 ) has a length (A) and an original inclination angle (B) preselected for being elastically compressed shallower in direct contact against said stowed door rim ( 44 ) to effect a preloaded compressive interference sealed fit therewith.

6. An assembly according to claim 4 wherein:
said door frame ( 32 ) includes forward and aft circumferentially arcuate legs ( 32 a ) and circumferentially opposite longitudinal legs ( 32 b ) surrounding said portal ( 36 ) and having an inside corner ( 58 ); and
said inner lip ( 56 ) includes a complementary inside corner ( 60 ) having an inclination angle (B) less than the inclination angle (B) outside said lip inside corner ( 60 ) to permit unwrinkled lateral contraction of said lip inside corner ( 60 ) when compressed against said door rim ( 44 ).

7. An assembly according to claim 6 wherein said inner lip inclination angle (B) is constant along said lip inside corner ( 60 ).

8. An assembly according to claim 4 wherein said secondary seal ( 48 ) further comprises a fire blanket ( 62 ) fixedly attached to said door frame ( 32 ) and integrally supporting said cantilever inner lip ( 56 ) in suspension upon said door rim ( 44 ).

9. An assembly according to claim 8 wherein said fire blanket ( 62 ) comprises thermal insulation for thermally protecting said door frame ( 32 ) and minimizing thermal distortion of said primary seal ( 46 ) and thereby minimizing size of said inner lip ( 56 ), with said inner lip ( 56 ) having a thickness (T) substantially less than the thickness (T 2 ) of said fire blanket ( 62 ).

10. An assembly according to claim 8 further comprising a narrow retainer ( 66 ) fixedly clamping said fire blanket ( 62 ) to said door frame ( 32 ) by a plurality of fasteners ( 64 ) extending through said door seat ( 34 ).

11. An assembly according to claim 4 wherein:
said hinge ( 50 ) bridges said cowl ( 26 ) and said door ( 38 ) at a forward end thereof, and said latch ( 52 ) bridges said cowl ( 26 ) and said door ( 38 ) at an aft end thereof;
said seal inner lip ( 56 ) detours around both said hinge ( 50 ) and said latch ( 52 ); and
said secondary seal ( 48 ) further includes a flexible outer lip ( 68 ) along the outer perimeter thereof extending in cantilever laterally outwardly from said door frame ( 32 ) for effecting a compression contact seal against said cowl inner skin ( 30 ) to seal leakage flow through said hinge ( 50 ) and said latch ( 52 ).

12. An assembly according to claim 11 wherein said cantilever outer lip ( 68 ) has a length (C) and an original inclination angle (D) preselected for being elastically compressed shallower in contact against said cowl inner skin ( 30 ) to effect a preloaded compressive interference sealed fit therewith.

13. An assembly according to claim 12 wherein:
said door frame ( 32 ) includes forward and aft circumferentially arcuate legs ( 32 a ) and circumferentially opposite longitudinal legs ( 32 b ) surrounding said portal ( 36 ) and having an outside corner ( 70 ); and
said outer lip ( 68 ) includes a complementary outside corner ( 72 ) having a corresponding length (C) and inclination angle (D) preselected to permit elastic expansion of said outer lip ( 68 ) upon compression against said cowl inner skin ( 30 ).

14. An assembly according to claim 12 wherein:
said cantilever inner lip ( 56 ) includes a length (A) and an original inclination angle (B) for being elastically compressed shallower in direct contact against said stowed door rim ( 44 ) to effect a preloaded compression interference sealed fit therewith; and
said length (C) of said outer lip is greater than said length (A) of said inner lip ( 56 ), and said inclination angle (D) of said outer lip is greater than said inclination angle (B) of said inner lip ( 56 ).

15. An assembly according to claim 12 wherein said secondary seal ( 48 ) further includes:
a hinge dome ( 74 ) covering said hinge ( 50 ) and extending laterally between said inner and outer lips ( 56 , 68 );
a latch dome ( 76 ) covering said latch ( 52 ) and extending laterally between said inner and outer lips ( 56 , 68 ); and
a plurality of narrow retainers ( 66 ) fixedly clamping said secondary seal ( 48 ) to said door frame ( 32 ) and terminating on opposite sides of said hinge and latch domes ( 74 , 76 ).

16. An assembly according to claim 15 wherein said secondary seal ( 48 ) further comprises a fire blanket ( 62 ) extending laterally between said inner and outer lips ( 56 , 68 ) and along

Assignees

• Gulfstream Aerospace Corp

Inventors

• Crawford Darwin Dean
• Shaeffer Clifford Frank
• Matlock Jerod Kennon

Classifications

• E05B65/102

  opening under pressure on the surface of the door itself (E05C19/02 takes precedence) · CPC title

• F05D2260/30

  Retaining components in desired mutual position · CPC title

• F01D21/14

  responsive to other specific conditions · CPC title

• B64C7/02 Primary

  Nacelles · CPC title

• F01D25/24

  Casings (modified for heating or cooling F01D25/14); Casing parts, e.g. diaphragms, casing fastenings (casings for rotary machines or engines in general F16M {; special arrangements in stators dealing with breaking-off of part of rotor F01D21/045}) · CPC title