# US 11,993,371 B2 · Thermal relief doors for overheat prevention of anti-ice systems on aircraft > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,993,371 B2 - Document ID: US11993371B2 - Status: Granted - Kind: B2 - Application number: 17/530,233 - Filed: 2021-11-18 - Published: 2022-08-18 - Granted: 2024-05-28 - Earliest claimed: 2021-02-15 - Assignees: The Boeing Company - Applicants: The Boeing Company - Inventors: Grzegorz G. Bogucki; Matthew J. Osborn; Art Ma; Saad Dawood - Web page: https://patentgrep.com/patent/US11993371B2 ## CPC - B64C 3/36: Structures adapted to reduce effects of aerodynamic or other external heating - B64C 9/14: forming slots - B64C 9/22: at the front of the wing - B64D 15/04: Hot gas application - B64D 29/08: Inspection panels for power plants - B64D 33/02: of combustion air intakes - B64D 45/00: Aircraft indicators or protectors not otherwise provided for - B64C 2009/143: {comprising independently adjustable elements for closing or opening the slot between the main wing and leading or trailing edge flaps} - B64D 2033/0233: {comprising de-icing means} - B64C: AEROPLANES; HELICOPTERS - B64D: EQUIPMENT FOR FITTING IN OR TO AIRCRAFT; FLIGHT SUITS; PARACHUTES; ARRANGEMENT OR MOUNTING OF POWER PLANTS OR PROPULSION TRANSMISSIONS IN AIRCRAFT ## Abstract Methods, apparatus, systems and articles of manufacture are disclosed for overheat prevention of anti-ice systems for aircraft. An example aircraft includes a wing, a slat movably coupled to the wing, the slat having a compartment to receive heated bleed air, the slat including a panel, an opening formed in the panel, a door in the opening of the panel of the slat, an edge of the door hingeably coupled to the panel, the door movable between a closed position and an open position, and a latch coupled to the panel, the latch to hold the door in the closed position, the latch constructed of a thermally sensitive material such that when a temperature inside of the compartment reaches a threshold temperature, the latch releases the door to enable the door to move to the open position to vent the heated bleed air from the compartment. ## Claims ### Claim 1 An aircraft comprising: a wing; a slat movably coupled to the wing, the slat having a compartment to receive heated bleed air, the slat including a panel, an opening formed in the panel; a door in the opening of the panel of the slat, an edge of the door hingeably coupled to the panel, the door to move from a closed position to an open position and to return from the open position to the closed position; a pin coupled to the door; and a latch coupled to the panel, the latch to hold the door in the closed position, the latch constructed of a thermally sensitive material such that when a temperature inside of the compartment reaches a threshold temperature, the latch releases the door to enable the door to move to the open position to vent the heated bleed air from the compartment, the latch including a torsion spring with a latch hook, the latch hook at least partially wrapped around the pin when the door is in the closed position, the latch hook to re-engage the pin when the temperature inside of the compartment falls below the threshold temperature and the door returns from the open position to the closed position. ### Claim 2 (depends on 1) The aircraft of claim 1, wherein the torsion spring is a first torsion spring, the aircraft further including a second torsion spring coupled between the edge of the door and the panel, the second torsion spring to bias the door to the closed position. ### Claim 3 (depends on 2) The aircraft of claim 2, wherein the second torsion spring is constructed of a thermally sensitive material such that when the temperature inside of the compartment reaches the threshold temperature, a stiffness of the second torsion spring reduces to enable the door to rotate to the open position. ### Claim 4 (depends on 1) The aircraft of claim 1, wherein the edge is a first edge, and where the latch is disposed adjacent a second edge of the door opposite the first edge. ### Claim 5 (depends on 1) The aircraft of claim 1, wherein the edge is a forward-most edge of the door, such that when the door moves from the closed position to the open position, the door rotates in a forward direction. ### Claim 6 (depends on 1) The aircraft of claim 1, wherein the door has an outer surface facing outward and an inner surface facing toward the compartment, the inner surface having a visual indicator. ### Claim 7 (depends on 6) The aircraft of claim 6, wherein the visual indicator includes at least one of a bright color, a pattern, a written warning, or instructions. ### Claim 8 A method of installing a thermal relief door on an aircraft, the method comprising: hingeably coupling an edge of a door to a panel of a slat at or near an opening in the panel such that the door is movable from a closed position to an open position and returnable from the open position to the closed position, the slat movably coupled to a wing of the aircraft, the panel at least partially defining a compartment in the slat, the compartment to receive heated air; coupling a pin to the door; coupling a latch to the panel, the latch including a torsion spring with a latch hook; and at least partially wrapping the latch hook around the pin to engage the latch with the door to hold the door in the closed position, the latch constructed of a thermally sensitive material such that when a temperature inside of the compartment reaches a threshold temperature, the latch releases the door to enable the door to move to the open position to vent the heated air from the compartment, the latch hook re-engages with the pin when the temperature falls below the threshold temperature and the door returns from the open position to the closed position. ### Claim 9 (depends on 8) The method of claim 8, wherein the torsion spring is a first torsion spring, the method further including coupling a second torsion spring between the edge of the door and the panel, the second torsion spring to bias the door to the closed position. ### Claim 10 (depends on 9) The method of claim 9, wherein the second torsion spring is constructed of a thermally sensitive material such that when the temperature inside of the compartment reaches the threshold temperature, a stiffness of the second torsion spring reduces to enable the door to rotate to the open position. ### Claim 11 (depends on 8) The method of claim 8, further including coupling a visual indicator on an inner surface of the door, the inner surface facing toward the compartment, the visual indicator including at least one of a bright color, a pattern, a written warning, or instructions. ### Claim 12 (depends on 8) The method of claim 8, wherein the edge is a first edge, and where the latch is disposed adjacent a second edge of the door opposite the first edge. ### Claim 13 (depends on 8) The method of claim 8, wherein the edge is a forward-most edge of the door, such that when the door moves from the closed position to the open position, the door rotates in a forward direction. ### Claim 14 A system for controlling temperature in a closed compartment, the system comprising: a panel on a slat coupled to an aircraft wing, the panel having an opening, the panel at least partially defining the closed compartment in the slat, the closed compartment to receive heated air; a door in the opening of the panel, a pin coupled to the door, an edge of the door rotatably coupled to the panel at a hinge, the door to rotate from a closed position in which the door covers the opening to an open position in which the door uncovers the opening and to return from the open position to the closed position; a torsion spring coupled between the edge of the door and the panel, the torsion spring to bias the door to the closed position, the torsion spring constructed from a thermally sensitive material, the torsion spring to reduce stiffness when a temperature inside of the closed compartment reaches a threshold temperature to enable the door to rotate to the open position to vent the heated air from the closed compartment; and a latch coupled to the panel, the latch including a second torsion spring and a latch hook, the latch to hold the door in the closed position, the latch hook at least partially wrapped around the pin when the door is in the closed position, the latch constructed of a thermally sensitive material such that when the temperature inside of the closed compartment reaches the threshold temperature, the latch releases the door, the latch hook to re-engage the pin when the temperature falls below the threshold temperature and the door returns from the open position to the closed position. ### Claim 15 (depends on 14) The system of claim 14, wherein the panel is a leading edge panel on an aircraft. ### Claim 16 (depends on 14) The system of claim 14, wherein the door has an outer surface facing outward and an inner surface facing toward the compartment, the inner surface having a visual indicator. ### Claim 17 (depends on 14) The system of claim 14, wherein the edge is a forward-most edge of the door, such that when the door moves from the closed position to the open position, the door rotates in a forward direction. ### Claim 18 (depends on 14) The system of claim 14, wherein the edge is a first edge, and where the latch is disposed adjacent a second edge of the door opposite the first edge. ### Claim 19 (depends on 16) The system of claim 16, wherein the visual indicator includes at least one of a bright color, a pattern, a written warning, or instructions.