Mechanical Delay Safety Latch and Method

Abstract

A time-delayed latch (100, 101) for securing a structure in a designated position includes: a housing (110); a fluid chamber (140) housed within the housing (110) for holding fluid (160); a pin (120) extending through and axially movable within and through the fluid chamber; and a release frame (180) movably secured within the housing. When the pin is in the latched position, the release frame engages with the pin to prevent axial movement of the pin. When the pin is in the unlocked position, the release frame disengages from the pin to allow axial movement of the pin. The axial movement of the pin between the latched and unlocked positions requires a predetermined duration. During operation, the axial movement of the pin between the unlocked and latched positions may occur faster than the predetermined duration.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to U.S. Patent Application Serial No. 17 / 390,392, filed July 30, 2021, the entire disclosure of which is incorporated herein by reference. Technical Field

[0003] The disclosure herein relates to apparatus and methods for controlling access to a designated area, particularly controlling access to an area adjacent to the cockpit of an aircraft. Specifically, the disclosure herein relates to a purely mechanical delayed latch and method capable of operating without the use of any electricity. Background Technology

[0004] The ability of an aircraft's flight crew to ensure access to the cockpit during flight is crucial in seeking to protect the health of all passengers on board. While there has been an increase in the use of so-called "hardened" cockpit doors (e.g., doors reinforced to resist attempts to force open or break them) in recent years, the reality remains that a member of the flight crew frequently needs to enter or exit the cockpit during flight, thus providing passengers with a brief opportunity to seek access to the cockpit when the cockpit door is temporarily open. To prevent this, the Federal Aviation Guideline is expected to require aircraft to have so-called "secondary barriers" to prevent unauthorized access to areas adjacent to the cockpit. These secondary barriers are typically not "hardened" or structurally reinforced to prevent anyone and everyone from entering areas blocked by the secondary barrier; instead, they are designed (e.g., for specified periods) to slow the speed at which any person otherwise seeks access to this restricted area when the hardened cockpit door is not secured. By slowing down the ability of unauthorized personnel to approach, for example, an unsecured cockpit door, any flight crew member in the restricted access area will immediately notice any such attempt to enter without authorization, and will thus be able to take action to protect, for example, the cockpit door from intrusion before such unauthorized personnel are able to breach the secondary barrier and gain access to the restricted access area.

[0005] Simultaneously, flight crew members still need to be able to open, close, and secure the secondary barriers to allow them to perform their routine duties during flight, and even to allow crew members assigned to the cockpit to access the lavatory when needed. Furthermore, since the purpose of the secondary barriers is to slow down rather than completely prevent unauthorized personnel from moving across them, it would be advantageous to have delayed latches or locks (e.g., keyless delayed latches or locks) on the secondary barriers to allow flight crew members to move throughout the aircraft when necessary without significantly interfering with their operations during flight. Currently, all such known delayed latches are electromechanical devices that require a power supply for their operation. However, the possibility of needing to provide the ability to deploy multiple secondary barriers at different locations throughout the aircraft compartment to establish multiple time-restricted access zones within the aircraft compartment will require electrical and / or communication connections (e.g., wires, cables, etc.) at each location in the aircraft where such delayed latches are needed. This not only increases installation costs during aircraft manufacturing but also adds complexity to aircraft operation, such as the controller used to operate this electromechanical time-delay latch. Therefore, there is a need for a purely mechanical time-delay latch that can be implemented without any electrical connection to any other component of the aircraft. Summary of the Invention

[0006] According to an example embodiment, a time-delayed latch is provided for securing a structure in a designated position. The latch includes: a housing; a fluid chamber housed within the housing; a fluid housed within the fluid chamber; a pin passing through or extending through the fluid chamber and configured to move axially within and through the fluid chamber; and a release frame movably secured within the housing. The release frame is configured to engage with the pin in a latched position to prevent axial movement of the pin and to disengage from the pin in an unlocked position to allow axial movement of the pin. The axial movement of the pin between the latched and unlocked positions requires a predetermined duration. The latch is configured such that the axial movement of the pin between the unlocked and latched positions can occur faster than the predetermined duration.

[0007] In some embodiments, the latch includes a handle attached to the proximal end of the pin.

[0008] In some embodiments of the latch, the pin includes a distal end opposite to the proximal end, which is axially extendable to the outside of the housing to engage with the structure.

[0009] In some embodiments of the latch, the distal end of the pin is configured to move from the unlocked position to the latched position, the distal end extending further away from the housing in the latched position than in the unlocked position.

[0010] In some embodiments of the latch, the engagement portion of the release frame is configured to engage with a notch formed in the pin when the pin is in the latched position.

[0011] In some embodiments, the latch includes a first resilient member configured to apply force to the release frame to press the engagement portion against the outer surface of the pin and to press the engagement portion into the notch when the notch is aligned with the engagement portion.

[0012] In some embodiments of the latch, the release frame is held within a groove in the housing such that the release frame can only move in a plane perpendicular to the direction of axial movement of the pin.

[0013] In some embodiments, the latch includes a second resilient member located within the fluid chamber, positioned between the disc-shaped portion of the pin and the bottom of the fluid chamber, wherein the second resilient member is configured to apply force to the disc-shaped portion to automatically move the pin from a latched position to an unlocked position when the engagement portion disengages from the notch.

[0014] In some embodiments of the latch, the fluid chamber includes a first region and a second region, the first region being located on a side of the disc opposite to the second region; the disc includes orifices formed through the thickness of the disc and configured such that fluid can move between the first and second regions as the pin moves between a latched position and a latched position; when the pin moves from the latched position to the latched position, the volume of the first region decreases and the volume of the second region increases; and when the pin moves from the latched position to the latched position, the volume of the first region increases and the volume of the second region decreases.

[0015] In some embodiments, the latch includes a flow restrictor configured to limit the flow rate of fluid flowing from the first region through the orifice to the second region as the pin moves from the latched position to the unlocked position, relative to the flow rate of fluid flowing from the second region through the orifice to the first region as the pin moves from the unlocked position to the latched position, such that the force acting on the disc due to the fluid flow through the orifice is smaller when the pin moves from the unlocked position to the latched position than when the pin moves from the latched position to the unlocked position.

[0016] According to another example embodiment, a method for controlling access to an area of ​​an aircraft is provided, the method comprising: setting a barrier movable between a closed position and an open position, wherein in the closed position, the area of ​​access to the aircraft is restricted by the barrier, and in the open position, the area of ​​access to the aircraft is not restricted by the barrier; setting a delayed latch for the barrier, the latch comprising: a housing; a fluid chamber housed within the housing; fluid housed within the fluid chamber; and a pin passing through or extending through the fluid chamber and axially movable within and through the fluid chamber from a latched position to a latched position and from a latched position to a latched position, wherein in the latched position... The method includes: a latch configured to prevent movement of a barrier in a latched position, in which the barrier is movable without obstruction from the latch; and a release frame movably secured within the housing; the method comprising: positioning a pin in a latched position, in which the release frame engages with the pin to prevent axial movement of the pin relative to the fluid chamber; and moving the release frame to disengage the release frame from the pin, such that the pin automatically moves from the latched position to an unlatched position; wherein moving the pin between the latched and unlatched positions requires a predetermined duration longer than the time required to move the pin from the unlatched position to the latched position.

[0017] In some embodiments of the method, the latch includes a handle attached to a proximal end of the pin, and the pin includes a distal end opposite to the proximal end, and the method includes extending the distal end of the pin axially away from the housing to engage a locking structure of a barrier of the aircraft; wherein the distal end of the pin is located outside the housing.

[0018] In some embodiments of the method, the barrier is a door, and the locking structure is a support arm with an opening formed and positioned such that when the door is in the closed position, the distal end of a pin can be inserted into the opening.

[0019] In some embodiments of the method, when the door is in the closed position, the distal end of the pin is aligned only for insertion into the opening.

[0020] In some embodiments of the method, the release frame includes an engagement portion that can selectively engage with a notch formed in the pin when the pin is in the latched position.

[0021] In some embodiments, the method includes positioning a first resilient member between the housing and the release frame such that the first resilient member applies force to the release frame to press the engagement portion against the outer surface of the pin and presses the engagement portion into the recess when the recess aligns with the engagement portion.

[0022] In some embodiments of the method, the release frame is held within a groove in the housing such that the release frame can only move in a plane perpendicular to the direction of axial movement of the pin.

[0023] In some embodiments, the method includes providing a second elastic member between the disc-shaped part of the pin and the bottom of the fluid chamber within the fluid chamber; and applying force to the disc-shaped part via the second elastic member to automatically move the pin from the latched position to the unlocked position when the engagement portion disengages from the notch.

[0024] In some embodiments of the method, the fluid chamber includes a first region and a second region, the first region being located on a side of the disc-shaped member opposite to the second region; and the disc-shaped member includes an orifice formed through the thickness of the disc-shaped member; the method includes moving fluid through the orifice between the first and second regions as the pin moves between a latched position and a latch-off position; wherein, as the pin moves from the latched position to the latch-off position, the volume of the first region decreases and the volume of the second region increases; and wherein, as the pin moves from the latch-off position to the latched position, the volume of the first region increases and the volume of the second region decreases.

[0025] In some embodiments, the method includes: providing a flow restrictor in a first region of the fluid chamber; and using the flow restrictor to limit the flow rate of fluid flowing from the first region through the orifice to the second region as the pin moves from the latched position to the unlocked position, relative to the flow rate of fluid flowing from the second region through the orifice to the first region as the pin moves from the unlocked position to the latched position, such that the force acting on the disc due to the fluid flow through the orifice is smaller when the pin moves from the unlocked position to the latched position than when the pin moves from the latched position to the unlocked position.

[0026] According to another example embodiment, an aircraft is provided, the aircraft including: an area of ​​the aircraft that must be temporarily restricted from access; a barrier movable between a closed position and an open position, wherein in the closed position the area of ​​access to the aircraft is restricted by the barrier and in the open position the area of ​​access to the aircraft is not restricted by the barrier; and a time-delay latch for the barrier. The latch includes: a housing; a fluid chamber housed within the housing; a fluid housed within the fluid chamber; a pin passing through or extending through the fluid chamber and axially movable within and through the fluid chamber from a latched position to a latched position and from a latched position to a latched position, wherein in the latched position the latch is disengaged from a barrier to allow movement of the barrier, and in the latched position the latch is engaged with the barrier to restrict movement of the barrier; and a release frame movably fixed within the housing; wherein the release frame is configured to engage with the pin in the latched position to prevent axial movement of the pin, and to disengage from the pin in the latched position to allow axial movement of the pin; wherein the axial movement of the pin between the latched position and the latched position requires a predetermined duration; and wherein the latch is configured such that the axial movement of the pin between the latched position and the latched position occurs faster than the predetermined duration.

[0027] Other features, characteristics, advantages, and possible derivatives will be apparent to those skilled in the art from the following description with reference to the accompanying exemplary drawings. All features described and / or depicted in the drawings, individually or in any combination, indicate the purposes disclosed herein. The dimensions and scale of the parts shown in the drawings are not drawn to scale. Attached Figure Description

[0028] The disclosure herein will be explained in more detail with reference to the accompanying drawings. The following example drawings illustrate this schematically:

[0029] Figure 1 This is an isometric view of a first example embodiment of a mechanically delayed latch that includes only mechanical components.

[0030] Figure 2 It is a housing with the latch omitted. Figure 1 A partial isometric view of the latch.

[0031] Figure 3 It is a case where the latch is omitted from the housing and the case is in the unlocked state. Figure 1 Side view of the latch.

[0032] Figure 4 It is a case where the latched housing is omitted and the device is in a latched state. Figure 1 Side view of the latch.

[0033] Figure 5 It is an isometric view of the door, in which latches are provided to secure the door in a designated position.

[0034] Figure 6 yes Figure 5 The image shows a portion of the door in an isometric view with respect to the latch, where the latch is in an unlocked state.

[0035] Figure 7 yes Figure 5 The front view of a portion of the door shown is with a latch, wherein the latch is in the unlocked state.

[0036] Figure 8 yes Figure 5 The diagram shows a perspective view of a door and a latch, wherein the latch is in a latched state engaged with the support arm of the door.

[0037] Figure 9 yes Figure 8 A detailed view of the view shown, in which the connection between the latch and the door's support arm is illustrated.

[0038] Figure 10 This is a rear view of a second example implementation of a time-delay latch that includes only mechanical components.

[0039] Figure 11 yes Figure 10 A front view of the latch, in which the front cover is omitted to show the internal structure of the latch.

[0040] Figure 12 yes Figure 10 Rear isometric view of the latch.

[0041] Figure 13 It is an isometric view of the pin used in any of the latches disclosed herein.

[0042] Figure 14 yes Figure 13 An isometric view of the pin, schematically illustrating fluid flow through the orifice of the pin flange.

[0043] Figure 15 yes Figure 13 A top view of a pin, in which flow restrictors are arranged around the pin to provide unidirectional flow resistance.

[0044] Figure 16 yes Figure 15 The isometric view of the pin and flow restrictor shown shows that the flow restrictor is axially spaced from the orifice due to the hydrodynamics and movement of the orifice plate away from the flow restrictor, so as to allow fluid to flow unrestricted through these orifices.

[0045] Figure 17 yes Figure 15 The isometric view of the pin and flow restrictor shown shows the flow restrictor positioned adjacent to the orifice of the orifice plate to at least partially block these orifices, thereby limiting the flow rate of fluid through the orifices.

[0046] Figure 18 This is an isometric view of another example embodiment of the fluid chamber, pin, and flow restrictor suitable for use in any of the latches disclosed herein.

[0047] Figure 19 yes Figure 18 The diagram shows a perspective view of the fluid chamber, pin, and flow restrictor.

[0048] Figure 20 yes Figure 18 and Figure 19 An isometric perspective view of a portion of the fluid chamber shown.

[0049] Figure 21 This is another example implementation of a current limiter suitable for use in any of the example latches disclosed herein. Detailed Implementation

[0050] This document discloses a time-delayed latch or time-delayed locking device capable of being fully mechanically operated. As used herein, "fully mechanical" means that the latches disclosed herein can provide the designed time-delayed opening function using only mechanical means without any electrical connection, power supply, or any similar means. Therefore, the latches disclosed herein advantageously do not contain any electrical connectors or wires. In short, the latches disclosed herein can only be deployed and retracted by human or other biological actions, such as pulling, pushing, pressing, or otherwise moving a lever (or other suitable structure) to move parts of the latch into a latched state or latched configuration, and pulling, pushing, pressing, or otherwise moving a button (or other suitable structure) to move parts of the latch (e.g., release after a predetermined period of time) to an unlatched state or unlatched configuration. The operation of the latch is not driven and / or assisted by electricity. The operation of the latch is not driven and / or assisted by the use of any other power source, which without exception includes electrical, hydraulic, and / or pneumatic power sources.

[0051] Figures 1 to 4 A first example embodiment of a time-delay latch, generally designated 100, is shown, which is capable of fully mechanical operation. Latch 100 includes a housing 110 for securing the latch to and / or within any desired structural element in any desired position and orientation. Figures 5 to 9The illustration shown below is an example diagram, described later herein, in which a latch 100 is mounted within a movable barrier (e.g., a secondary barrier) of an aircraft. The latch includes a fluid chamber 140 housed within a housing 110. A pin 120 passes through or extends through the fluid chamber 140. The fluid chamber 140 is filled with fluid 160 (e.g., partially filled, including at least 50% or at least 75%; substantially completely filled, including at least 90%, at least 95%, or at least 99%; or completely filled, including 100%).

[0052] Pin 120 has a disc-shaped member 122, which is rigidly attached to pin 120 (e.g., integrally or by an attachment method such as welding, brazing, etc.). The disc-shaped member and / or fluid chamber 140 have fluid channels formed therein to allow fluid 160 to flow through the fluid channels in a prescribed manner. Pin 140 is positioned such that at least a portion of pin 140, including the disc-shaped member 122, is received within fluid chamber 140. Thus, fluid chamber 140 is subdivided by disc-shaped member 122 into a first region generally indicated as 150A on one side of disc-shaped member 122 and a second region generally indicated as 150B on the opposite side of disc-shaped member 122. The volumes of the first region 150A and the second region 150B vary based on the position of disc-shaped member 122 within fluid chamber 140. Thus, when latch 100 is in Figure 4 In the latched state shown, the volume of the first region 150A is larger than the volume of the second region 150B. When latch 100 is in... Figure 3 When the latch is released as shown, the volume of the first region 150A is smaller than the volume of the second region 150B. In some embodiments, the latch 100 may be designed such that the permissible range of movement of the disc 122 within the fluid chamber 140 can be limited such that the volume of the first region 150A is always greater than the volume of the second region 150B; the opposite arrangement is also possible, wherein the volume of the second region 150B is always greater than the volume of the first region 150A.

[0053] Fluid 160 is any suitable fluid with a desired viscosity, which can be selected based on a specific application and also based on the number, size, length, etc., of fluid channels in latch 100, such that latch 100 is designed such that a predetermined amount of time elapses between the time when latch 100 is triggered (e.g., released) and the time during which the structure secured by latch 100 can move freely (e.g., without interference from latch 100). Examples of fluids suitable for use in fluid chamber 140 may include, for example, but not limited to, water, oil, and even air in some embodiments.

[0054] Fluid 160 is contained within a fluid chamber 140, which includes an elongated outer body, a top 144, and a bottom 142, the top 144 and bottom 142 being sealed to the elongated outer body. In the illustrated embodiment, the elongated outer body is generally cylindrical prism-shaped. Advantageously, the disc 122 and the elongated outer body have the same cross-sectional shape, such that the fluid passage surrounding the disc 122 within the fluid chamber 140 is minimized and / or controlled. Thus, in the illustrated exemplary embodiment, the disc 122 has a generally circular profile or cross-sectional area when viewed along the longitudinal axis of the pin 120. The bottom 142 and the top 144 have corresponding holes or channels formed through the bottom 142 and the top 144 (e.g., through the entire thickness of the bottom 142 or the top 144). The holes in the top 144 are advantageously aligned with the holes in the bottom 142 (e.g., coaxial with and aligned along the longitudinal axis of the pin 120 and / or the fluid chamber 140). Pin 120 is positioned through holes formed in bottom 142 and top 144, and disc 122 is received within fluid chamber 140 and between bottom 142 and top 144. Advantageously, at least one of the holes in bottom 142 and top 144 has a seal disposed in said at least one hole, such that a fluid seal (e.g., a leak-proof or leak-resistant seal) is provided in bottom 142 and / or top 144 between pin 120 and fluid chamber 140. It is particularly advantageous that such a fluid seal in both bottom 142 and top 144 between pin 120 and fluid chamber 140 prevents fluid 160 from leaving fluid chamber 140 at any point where pin 120 passes through or extends through the outer wall of fluid chamber 140.

[0055] Pin 120 extends beyond the top 144 of fluid chamber 140 in a first direction and is rigidly attached to handle 200, which may have any shape configured for easy operation by, for example, a person, and particularly a member of the flight crew of an aircraft. Pin 120 also extends beyond the bottom 142 of fluid chamber 140 in a second direction opposite to the first direction and includes a notch generally indicated as 128 formed in the outer surface of pin 120. Notch 128 may have any suitable shape and / or size, but is advantageously designed to have at least one surface recessed relative to the outer surface of pin 120 (e.g., inward in the circumferential direction of pin 120). Advantageously, notch 128 is formed at a point along the length of pin 120 such that no portion of notch 128 exceeds, or even partially exceeds, the bottom 142 of fluid chamber 140, as this would introduce a leakage path for fluid 160 to leak from fluid chamber 140.

[0056] The latch 100 also includes a release frame 180 that surrounds the pin 120 and extends at least partially behind the pin 120 and is at least slidably secured within the housing 110, and is positioned relative to the pin 120 such that an engagement portion 182 of the release frame 180 is configured to engage within a recess 128 of the pin 120. In the illustrated example embodiment, the release frame 180 is substantially movable only within a plane defined in a groove 114 of the housing 110, in which the release frame 180 is positioned. As used herein, the term “substantially movable only within” generally refers to an arrangement that, taking into account assembly tolerances, will necessarily leave a negligible gap between the groove 114 and the edge of the release frame 180 to allow the release frame 180 to move freely within the plane of motion defined by the groove (e.g., without constraint and with only negligible frictional resistance due to contact with the housing 110). In the illustrated example embodiment, the plane of motion of the release frame 180 is substantially orthogonal or substantially perpendicular to the longitudinal axis of the pin 120, thereby defining the movement profile of the pin 120 within the latch 100. Furthermore, the term "substantially orthogonal" means that the arrangement is designed to be orthogonal between the plane of motion of the release frame 180 and the pin 120, but allows for negligible misalignment (e.g., less than 5°, less than 2°, or less than 1°) between the longitudinal axis of the pin 120 and the plane of motion of the release frame 120. This misalignment is necessary to account for tolerance variations between the components that will allow for reliable assembly of the latch 100.

[0057] The latch 100 may also have an actuator 190, which, in the example embodiment shown herein, may be in the form of a button and rigidly attached to the end of the release frame 180 opposite to the engagement portion 182. The latch 100 also has a first resilient member 210, which, in the example embodiment shown herein, is in the form of a coil spring and is positioned between the rear wall 116 of the housing 110 and the engagement portion 182 of the release frame 180. The first elastic member 210 is designed and positioned to apply a force to the engagement portion 182 of the release frame 180, which biases the release frame 180 in the plane of motion away from the rear wall 116 (or any other surface that the first elastic member 210 may be positioned against or seated against), such that the engagement portion 182 is held against the outer surface of the pin 120 (e.g., in direct contact with the outer surface of the pin 120), and as the pin 120 moves vertically relative to the release frame 180, such that when the pin 120 has moved a distance sufficient to vertically align the notch 128 with the engagement portion 182 (e.g., when the notch 128 is positioned in the plane of motion of the release frame 180), the engagement portion 182 automatically moves into the notch 128. Due to the biasing force exerted by the first elastic member 210 on the release frame 180, the engagement portion 182 will remain engaged (e.g., in a barrier manner) within the notch 128 unless the release frame 180 moves a sufficient distance in the plane of motion and / or until the aforementioned condition occurs, causing the engagement portion 182 to move out of the notch 120, thereby allowing the pin 120 to move vertically approximately along the longitudinal axis of the pin 120.

[0058] Actuator 190 is configured to be pushed, pulled, pressed, or otherwise moved by, for example, a person (e.g., a member of the flight crew of an aircraft), and this movement is then transmitted (e.g., directly transmitted) to release frame 180 to move release frame 180 in a plane of motion, thereby removing engagement portion 182 from recess 128 (e.g., completely removing it). In some embodiments, for example, when the latch is mounted such that actuator 190 extends into or is adjacent to a high-flow area, it may be advantageous to connect actuator 190 to release frame 180 in a damped or isolated manner. For example, a spring or other suitable damper may be used to connect actuator 190 to release frame 180 such that accidental contact with actuator 190 does not result in accidental release of latch 100.

[0059] The latch 100 includes a second resilient member 170 (e.g., a coil spring or other suitable resiliently compressible member) fully positioned within a second region 150B of the fluid chamber and between the disc 122 and the bottom 142 of the fluid chamber 140. Therefore, the second resilient member 170 is configured to apply a force to the disc 122 in a vertical direction (e.g., in the longitudinal direction of the pin 120), and thereby apply a force to the pin 120. Figure 4 As shown, when the engagement portion 182 is positioned within the recess 128, the second elastic member 170 is compressed within the fluid chamber 140, and the volume of the second region 150B is smaller than the volume of the first region 150A. When the second elastic member 170... Figure 4 When compressed as shown, the second elastic member 170 applies an expanding force to the disc-shaped member 122, such that when the engaging portion 182 moves out of the notch 128, this expanding force causes the pin 120 to move automatically in the longitudinal direction, increasing the length of the second elastic member 170 and the volume of the second region 150B, while the volume of the first region 150A decreases by a proportional amount, until the latching components are arranged in position. Figure 3 Until the latched state is shown. Similarly, handle 200 is configured to transmit input received at handle 200 (e.g., by being moved) directly to pin, causing pin 120 to move vertically, resulting in a proportional decrease in the volume of second region 150B and an increase in the volume of first region 150A, until the latching components are arranged in the unlocked state. Figure 4 Up to the latched state shown, in which the engaging portion 182 presses against the outer surface of the pin 120 as the pin 120 moves due to the force applied by the first elastic member 210, and thus automatically engages with the notch 128 (e.g., inserts into the notch 128) after the pin 120 has moved a sufficient amount to position the notch 128 and the engaging portion 182 in substantially the same plane (e.g., the plane of movement of the release frame 180).

[0060] The latch 100 is designed and configured such that its components can move from a latched state to a latched state substantially instantaneously (e.g., within 1 second), but the movement from the latched state to the latched state cannot occur without a predetermined amount of time, which can be selected based on the application and environment in which the latch 100 is installed. In discussing exemplary embodiments, reference will be made herein to a predetermined time of at least 5 seconds; however, the latch 100 can be designed to provide virtually any other amount of time while moving between the latched and latched states.

[0061] In the example embodiments disclosed herein, hydrodynamic properties are utilized in the design of latch 100 to provide a specified time delay between the latched state and the unlocked state. In the example embodiments disclosed herein, one or more (e.g., multiple) orifices 122H are provided in the form of holes throughout the entire thickness of the disc 122. The size and orientation of the orifices 122H are selected based on the properties of the fluid 160 (e.g., viscosity, etc.) such that when the pin 120 moves vertically between the unlocked and latched states, a negligible force is applied to the pin due to the flow of fluid 160 through the orifices 122H, thereby allowing latch 100 to be set substantially instantaneously (e.g., within less than 1 second) from the unlocked state to the latched state. As used herein, the term "negligible force" is used to mean a force that is at least an order of magnitude lower than the force generated by the flow of fluid 160 through the orifices 122H as the pin 120 moves vertically between the latched and unlocked states. Figure 14 As shown, fluid 160 is configured to flow bidirectionally through orifice 122H of pin 120 as pin 120 moves within fluid chamber 140.

[0062] The pin 120 includes a distal end 124 that, when latched, extends through the bottom wall 119 of the housing 110 and engages in a corresponding slot, hole, channel, or other similar structure formed in or attached to a structure that prevents and / or impedes movement (e.g., opening movement) of a movable structure, such as a secondary barrier of an aircraft, when the distal end 124 is inserted therein. The distal end 124 of the pin may include an optional beveled edge 126 for allowing the pin 120 to slide into or disengage from a recess in a structure secured by the latch 100, depending on its orientation, as exemplarily described in… Figures 5 to 9 It is shown in the figure and will be described further elsewhere in this document.

[0063] Figures 15 to 18 Various aspects of an example embodiment of a latch 100, including a current limiter 130 in a generally annular configuration, are shown, the current limiter 130 being concentrically arranged around a pin 120 within a first region 150A. From Figures 14 to 18 The structure of the fluid chamber 140 is omitted from the illustrations in order to better illustrate the features shown in these figures. For example... Figure 15As shown, each of the orifices 122H has approximately the same size and shape, and is formed circumferentially around the disc at the same distance measured radially from the longitudinal axis of the pin 120. The flow limiter 130 has an inner radius approximately similar to the outer radius of the pin 120, and a constant outer radius between the inner and outer edges of the orifices 122H, such that when the flow limiter 130 is positioned adjacent to the upper surface of the disc 122 (e.g., adjacent to or in direct contact with the upper surface of the disc 122 by a thickness less than that of the flow limiter 130), the flow limiter 130 will block a portion of each of the orifices 122H. The flow limiter is positioned within a first region 150A because when the pin 120 moves from a latched state to an unlocked state, the disc 122 will move toward the flow limiter 130, such that as the pin moves toward... Figure 3 As the latch-off position is moved, the flow restrictor 130 will be biased against the orifice 122H and the disc 122. The frictional force caused by the flow of fluid 160 through the orifice 122H will also cause a force to be applied to the flow restrictor 130 in the direction of the surface of the disc 122 to hold the flow restrictor 130 against the surface of the disc 122 when the pin 120 moves to the latch-off position.

[0064] However, when pin 120 moves from the unlocked position to the latched position, latch 100 is configured such that flow restrictor 130 will at least temporarily space from the surface of disc 122—on which or through which orifices 122H are formed—to substantially allow the entire diameter of each orifice in orifice 122H to be unobstructed for allowing fluid 160 to flow from second region 150B to first region 150A. In the example embodiment described herein, when the longitudinal axis of pin 120 is aligned with gravity, gravity will cause flow restrictor 130 to move gradually (e.g., at a slower rate than disc 122) through fluid chamber 160 so that it rests (e.g., directly against) disc 122 when pin is in the latched position, thereby automatically and immediately restricting the flow of fluid 160 through orifice 122H as engagement portion 182 moves away from recess 128. Therefore, in some embodiments, the positioning of the current limiter 130 on the disc 122 is controlled solely by gravity and the movement of the disc 122 itself.

[0065] In some cases, the current limiter 130 may not be aligned properly; the current limiter 130 may "get stuck" or be unable to move at a certain point along the length of the pin 120. Figure 17 The position shown is such that the force of gravity acting solely on the current limiter 130 would be insufficient to move the current limiter to the desired location. Figure 17In the position shown, the flow restrictor 130 is held at a position along the length of the pin 120 and spaced apart from the disc 122, such that for at least a portion of the pin's travel between the latched and unlocked positions, the flow of fluid 160 through the orifice 122H will not be restricted by the flow restrictor 130, thereby potentially causing the amount of time elapsed between the time when the actuator 190 is actuated and the time when the pin 120 moves into the unlocked position to be less than the specified amount of time required for the particular application or installation environment of the latch 100.

[0066] To avoid such misalignment, it is conceivable that a third elastic member 132, in the form of a so-called "assistant" spring, can be provided between the flow restrictor 132 and the top 144 of the fluid chamber 140. This third elastic member 132 is shown as a generally helical helical spring. Therefore, as the pin 120 moves from the latched position to the unlocked position within the fluid chamber and the fluid 160 flows from the first region 150A through the orifice 122H into the second region 150B, the third elastic member is compressed. The third elastic member 132 is designed such that the force applied to the flow restrictor 130 is less than the force applied to the disc by the second elastic member 170. Particularly advantageously, even when the pin 120 is in the latched position... Figure 3 When the latch is released, the third elastic member 132 also generates a force at least an order of magnitude smaller than that generated by the second elastic member 170. The sole purpose of the third elastic member 132 is to apply a substantially uniform force around the circumference of the current limiter 130, so that the current limiter 130 remains substantially parallel to the disc 122 to prevent the current limiter 130 from becoming trapped on the pin 120. In some embodiments, the force applied by the third elastic member 132 is further advantageously small enough to ensure that as the pin 120 moves from the latch position... Figure 3 The unlock position is moved to Figure 4 In the latched position, the flow restrictor 130 remains spaced apart from the surface of the disc 122, thereby allowing fluid 160 to flow substantially unimpeded from the second region 150B through the orifice 122H into the first region 150A. This in Figure 16 As shown, pin 120 is shown moving vertically downwards, fluid 160 (indicated by the arrow passing through orifice 122H) flows through orifice 122H in the opposite direction to the movement of pin 120, and flow restrictor 130 is spaced apart from the surface of disc 122, such that orifice 122H remains substantially unobstructed. The opposite is true in... Figure 17As shown, pin 120 is shown moving vertically upward, fluid 160 (indicated by an arrow passing through orifice 122H) flows through orifice 122H in a direction opposite to the direction of movement of pin 120, and flow restrictor 130 is adjacent to the surface of disc 122 (e.g., in direct contact with the surface of disc 122), such that orifice 122H is at least partially blocked due to the positioning of flow restrictor 130.

[0067] In some embodiments, alternative implementations of the flow restrictor may include a flexible membrane, a portion of which is adhesively and / or mechanically attached to a disc-shaped element, wherein portions not attached to the disc-shaped element are selectively displaced away from the surface of the disc-shaped element with orifices, depending on the direction of fluid flow through the orifices. In such embodiments, the flow restrictor may be: a generally annular element similar to flow restrictor 130; one or more segments, each of which is associated with and (e.g., selectively) at least partially covers one of the orifices; fingers that form a generally annular element and extend radially to cover at least a portion of one or more of the orifices; or combinations thereof.

[0068] Figures 18 to 20 Other example embodiments of the fluid chamber 140 are shown, wherein a channel 148 for allowing fluid 160 to flow between a first region 150A and a second region 150B of the fluid chamber 140 is provided on the inner peripheral surface of the fluid chamber 140. Figures 18 to 20 In the example embodiment shown, channel 148 extends over all or a portion (e.g., most) of fluid chamber 140. Channel 148 may be used in place of or in conjunction with orifice 122H formed in disc 122, and operates on the same hydrodynamic basis as orifice 122h described elsewhere herein. In the case of combined use, fluid 160 flows both through orifice 122H and around disc 122 as pin 120 moves relative to fluid chamber 140.

[0069] Figure 21An alternative embodiment of a current limiter, generally designated 300, is shown, which can be used substantially interchangeably with the current limiter 130 described elsewhere herein. The current limiter 300 has a plate 310 and a shaft 320, which are joined together and have an opening 330 formed through each. The use of the shaft 320 is advantageous because, compared to the current limiter 130, the increased length and mass of the current limiter 300 significantly reduces the risk of the current limiter becoming stuck or trapped on the pin 120, even if this risk cannot be completely eliminated. It is considered advantageous that the length of the opening 330 is the same as or greater than the diameter of the pin 120.

[0070] Figures 10 to 12 Various aspects of another example embodiment of a purely mechanical time-delay latch, generally designated 101, are shown. Many components of latch 101 are substantially the same as those of latch 100, and unless described differently herein with respect to latch 101, similarly numbered latches 100 and 101 share the same or at least substantially similar features or structures. Each latch of 100 and 101 includes a cover plate 112 that covers the front portion of housing 110 and prevents access to the components of latch 100 and 101 housed within housing 110. The main differences between latch 101 and latch 100 lie in the orientation of the release frame 180 and its direction of movement within housing 110, as well as the positioning of the first resilient member 210 and the notch 128. In latch 101, each of the release frame 180, actuator 190, first elastic member 210, and notch 128 is rotated approximately 90° relative to the housing in the orientation shown in latch 100. Therefore, using latch 101, handle 200 can be accessed from one side of the structure where latch 101 is mounted, and actuator 190 can be accessed from the other side of the structure (e.g., the opposite side). In embodiments where latch 101 is mounted on a movable barrier, such as a segmented secondary barrier of an aircraft, where the actuator 190 of latch 100 will protrude into, for example, a walkway or other high-traffic area, the position of actuator 190 of latch 101 can help prevent accidental actuation of actuator 190 because actuator 190 can be positioned within the gaps formed between, for example, the segments of the segmented secondary barrier.

[0071] Figures 5 to 9 An example implementation of an access control system, generally designated 10, is shown. This access control system includes a door, a delayed latch, generally designated 100, and a support arm 40. While the door can have any suitable construction and can be, for example, an aircraft door or part of an aircraft door system, in… Figures 5 to 9In the example embodiment shown, the door is a segmented, laterally expandable door, allowing it to be installed to selectively control access through any suitable opening, the width of which lies between the door's minimum and maximum width. Furthermore, such a segmented door can be advantageously used in space-constrained locations, such as within an aircraft, to allow for a narrower (e.g., smaller) width when retracted compared to when extended (e.g., fixed across the opening used for access control). Therefore, Figures 5 to 9 The segmented door includes a first segment 20 and a second segment 30. The first segment 20 and the second segment 30 have so-called "finger-like portions" that extend toward the opposite segments of the door and at least partially intersect with the finger-like portions of the opposite segments. Thus, the finger-like portions of the first segment 20 at least partially intersect with the finger-like portions of the second segment 30. As used herein, the term "width" refers to the distance between the farthest edges of the first segment 20 and the second segment 30, while "thickness" is defined as the shortest distance between opposite edges of the same structure of the door and is generally measured in a direction orthogonal to the width dimension.

[0072] The first segment 20 includes a slot and a time-delay latch 100, in which a support arm 40 is pivotally positioned. Figure 5 In the diagram, the door is shown in a retracted position, in which the outer surface of the support arm 40 is shown to be coplanar with the outer surfaces of the first segment 20 and the second segment 30, respectively. As shown, the door can extend along the outer edge of the first segment 20 towards the edge (i.e., as...). Figure 5 (as shown at the rightmost edge) pivots. The latch 100 is securely attached to a recess formed in the first segment 20. The arrangement of the support arm 40 and the latch 100 attached to the first segment 20 can be similar to... Figures 5 to 9The arrangement shown is reversed, allowing the latch 100 and support arm 40 to be attached to the second segment 30. In some embodiments, the latch 100 and support arm 40 may be attached to different segments of the door (e.g., 20, 30). To prevent access to the internal components of the latch 100, the latch 112 includes a cover plate 112 that (e.g., except for a slot defining the path of movement of the handle 200) substantially conceals the components of the latch 100 housed within the housing 110. Thus, the only visible components of the latch 100 outside the first segment 110 are the cover plate 112 where the handle slot is formed, the handle 200, the actuator 190, and any portion of the release frame 180 extending beyond the cover plate 112 to allow movement of the actuator 190 relative to the cover plate 112. In some embodiments, decorative elements may be provided above and / or within the handle slot to further conceal the contents of the housing 110. Such decorative elements may include, for example, bristles that can be displaced by movement of the handle 200; or a sheet attached to the handle 200 within the housing 110 such that the sheet and the handle 200 move simultaneously within the handle groove of the cover plate 112.

[0073] The support arm 40 includes a protrusion 44 having a recessed opening 46 formed as (e.g., along the longitudinal axis of the pin 120) passing through at least a portion of the protrusion 44. The opening 46 may have a similar shape to the pin 120, for example, in... Figure 9 The dimensions at the distal end 124 and the inclined edge 126 shown are substantially similar to the external dimensions (e.g., the external dimensions are large enough to account for tolerances between parts and assemblies and also to ensure a firm engagement and proper alignment between the pin 120 and the opening 46).

[0074] The latch 100 includes a pivot pin 42 pivotally attached between a support arm and a portion of the latch 100, such as the bottom 119 of the housing 110, such that the support arm is pivotally secured to the first section 20 of the door by a rigid attachment of the latch 100 to the first section 20. Therefore, when the pin 120 is in the unlocked state, the support arm 40 is pivotable relative to the first section 20 and, in addition, relative to the entire door, about the pivot pin 42. When the opening 46 of the protrusion 44 is axially aligned with the pin 120 (e.g., the distal end 124 of the pin 120), the handle 200 can be accessed from the... Figures 5 to 7 The unlocked position shown in the overall diagram moves to... Figure 8In the latching position shown, this directly and simultaneously inserts the distal end 124 of pin 120 into the opening 46 of protrusion 44. Preferably, protrusion 44 and support arm 44 are shaped such that axial movement of pin 120 (e.g., along the longitudinal direction of pin 120) is physically blocked by the structure of support arm 124. As used herein, the term "physical blocking" allows negligible axial movement between the distal end 124 of pin 120 and the upper surface of support arm 40, which is closest to the distal end 124 and is generally positioned in a plane parallel to the plane defined by the distal end 124, such as... Figures 5 to 9 As shown in the diagram. Therefore, the pin 120 can only be moved into the latched position when the distal end 124 of the pin 120 is aligned with the opening 46 of the support arm 40 to a degree sufficient to allow the distal end 124 of the pin 120 to be inserted into the opening 46 a certain distance—a distance sufficient to allow the engagement portion 182 of the release frame 180 to engage in the notch 128 of the pin 120 by the first elastic member 210—and thus the latch 100 can be set to the latched state.

[0075] When the distal end 124 of pin 120 has been inserted into the opening 46 of support arm 40, support arm 40 is locked in place relative to latch 100 and first segment 20 until pin 120 has completely disengaged from opening 46 by pushing actuator 190 to disengage engagement portion 182 from notch 128 and thus allowing second elastic member 170 to move disc-shaped part 122 of pin 120 axially away from support arm 40 within fluid chamber 140. This requires a predetermined amount of time based on the number and geometry of orifices 122H and flow restrictors 130, as well as the characteristics of fluid 160 contained within fluid chamber 140. Therefore, system 10 can restrict entry from outside the door for a predetermined period of time required for components of latch 100 to move from latched position to unlocked position.

[0076] Although the orientation of the components and the relative movement of the handle 200, pin 120, and fluid chamber 140 during actuation of the latch 100 are shown herein in a generally vertical orientation, opposite (vertical) orientations and operations of the components of the latch 100 are also included in this disclosure. Additionally, in some embodiments, the latch 100 may be aligned such that the longitudinal axis of the pin 120 is not vertically aligned (e.g., not vertically aligned with gravity when mounted on a structure oriented to a flat surface of the earth), but rather tilted relative to the vertical direction, including mounting of the pin 120 orthogonal or perpendicular to the vertical direction shown in the example embodiments disclosed herein. In some other embodiments, the pin 120 may also have a bifurcated or segmented longitudinal axis, such that the pin 120 comprises multiple segments joined together, but wherein these segments are not necessarily all coaxially aligned with each other, such that the holes formed in the bottom 142 and top 144 of the fluid chamber 140 are misaligned relative to each other (e.g., non-axial).

[0077] It should be understood that the exemplary embodiments disclosed herein are not limiting and do not restrict the purposes disclosed herein. In particular, it will be apparent to those skilled in the art that the features described herein can be combined with each other arbitrarily, and / or various features can be omitted, without departing from the subject matter disclosed herein in any resulting apparatus, system, and / or method.

[0078] Although at least one exemplary embodiment of the invention has been disclosed herein, it should be understood that modifications, substitutions, and alternatives will be readily apparent to those skilled in the art and can be made without departing from the scope of this disclosure. This disclosure is intended to cover any modifications or variations of the exemplary embodiments. Furthermore, in this disclosure, the terms "comprising" or "including" do not exclude other elements or steps, the terms "a," "an," or "one" do not exclude a plural, and the term "or" means either or both. Moreover, unless otherwise stated in this disclosure or the context, the features or steps already described may also be used in combination with other features or steps and may be used in any order.

Claims

1. A time-delay latch for fixing a structure in a designated position, the latch comprising: case; A fluid chamber, which is housed within the housing, for retaining fluid within the fluid chamber; A pin that extends through the fluid chamber and is configured to move axially within and through the fluid chamber; as well as A release frame, which is movably fixed within the housing; The release frame is configured to engage with the pin when the pin is in the latched position to prevent axial movement of the pin, and to disengage from the pin when the pin is in the unlatched position to allow axial movement of the pin. Wherein, the axial movement of the pin from the latched position to the unlocked position requires a predetermined duration; and The latch is configured such that the axial movement of the pin from the unlocked position to the latched position occurs faster than the predetermined duration.

2. The latch of claim 1, further comprising a handle attached to the proximal end of the pin.

3. The latch according to claim 2, wherein, The pin includes a distal end opposite to the proximal end, the distal end being axially extendable to the outside of the housing to engage with the structure.

4. The latch according to claim 3, wherein, The distal end of the pin is configured to move from the unlocked position to the latched position, the distal end extending further away from the housing in the latched position than in the unlocked position.

5. The latch according to claim 3, wherein, The engagement portion of the release frame is configured to engage with a notch formed in the pin when the pin is in the latch position.

6. The latch of claim 5, further comprising a first resilient member configured to apply force to the release frame to press the engagement portion against the outer surface of the pin and to press the engagement portion into the recess when the recess is aligned with the engagement portion.

7. The latch according to claim 5, wherein, The release frame is held within the groove of the housing such that the release frame can only move in a plane perpendicular to the direction of the axial movement of the pin.

8. The latch of claim 6, further comprising a second resilient member located within the fluid chamber, the second resilient member being positioned between the disc-shaped portion of the pin and the bottom of the fluid chamber, wherein, The second elastic member is configured to apply force to the disc-shaped member to automatically move the pin from the latched position to the unlocked position when the engagement portion disengages from the notch.

9. The latch according to claim 8, wherein: The fluid chamber includes a first region and a second region, the first region being on the side of the disc-shaped member opposite to the second region; The disc-shaped member includes an orifice formed through the thickness of the disc-shaped member and configured such that fluid can move through the orifice between the first region and the second region as the pin moves between the latched position and the unlocked position. The latch is configured such that when the pin moves from the latched position to the unlocked position, the volume of the first region decreases and the volume of the second region increases; and The latch is configured such that as the pin moves from the unlocked position to the latched position, the volume of the first region increases and the volume of the second region decreases.

10. The latch of claim 9, further comprising a flow limiter configured to limit the flow rate of fluid flowing from the first region through the orifice to the second region as the pin moves from the latched position to the unlocked position, relative to the flow rate of fluid flowing from the second region through the orifice to the first region as the pin moves from the unlocked position to the latched position, such that the force acting on the disc due to the fluid flow through the orifice is smaller when the pin moves from the unlocked position to the latched position than when the pin moves from the latched position to the unlocked position.

11. A method for controlling access to an area of ​​an aircraft, the method comprising: A barrier is provided that can move between a closed position and an open position, wherein in the closed position, access to the area of ​​the aircraft is restricted by the barrier, and in the open position, access to the area of ​​the aircraft is not restricted by the barrier; A time-delay latch is provided for the barrier, the latch comprising: case; A fluid chamber, which is housed within the housing, for retaining fluid within the fluid chamber; A pin extending through the fluid chamber and axially movable within and through the fluid chamber from a latched position to a latched position and from the latched position to a latched position, wherein in the latched position the latch is configured to prevent movement of the barrier, and in the latched position the barrier is movable without obstruction from the latch; and A release frame, which is movably fixed within the housing; Positioning the pin in the latched position, in which the release frame engages with the pin to prevent axial movement of the pin relative to the fluid chamber; and The release frame is moved to disengage from the pin, causing the pin to automatically move from the latched position to the unlocked position. The specified duration is longer than the time required for the pin to move from the latched position to the unlocked position.

12. The method according to claim 11, wherein, The latch includes a handle attached to a proximal end of the pin, and the pin includes a distal end opposite to the proximal end, the method comprising: The distal end of the pin extends axially away from the housing to engage with the locking structure of the barrier of the aircraft; The distal end of the pin is located outside the housing.

13. The method according to claim 12, wherein, The barrier is a door, and the locking structure is a support arm with an opening formed and positioned such that when the door is in the closed position, the distal end of the pin can be inserted into the opening.

14. The method according to claim 13, wherein, When the door is in the closed position, the distal end of the pin is aligned only for insertion into the opening.

15. The method according to claim 12, wherein, The release frame includes an engagement portion that, when the pin is in the latched position, can selectively engage with a notch formed in the pin.

16. The method of claim 15, comprising: The first elastic member is positioned between the housing and the release frame such that the first elastic member applies a force to the release frame to press the engagement portion against the outer surface of the pin and press the engagement portion into the recess when the recess is aligned with the engagement portion.

17. The method according to claim 15, wherein, The release frame is held within the groove of the housing such that the release frame can only move in a plane perpendicular to the direction of the axial movement of the pin.

18. The method of claim 15, comprising: A second elastic member is provided in the fluid chamber between the disc-shaped part of the pin and the bottom of the fluid chamber; as well as A force is applied to the disc-shaped member via the second elastic member to automatically move the pin from the latched position to the unlocked position when the engagement portion disengages from the notch.

19. The method of claim 18, wherein: The fluid chamber includes a first region and a second region, the first region being on the side of the disc-shaped member opposite to the second region; and The disc-shaped member includes an opening formed to extend through the thickness of the disc-shaped member; The method includes moving fluid through the orifice between the first region and the second region as the pin moves between the latched position and the unlocked position; When the pin moves from the latched position to the unlocked position, the volume of the first region decreases and the volume of the second region increases; and When the pin moves from the unlocked position to the latched position, the volume of the first region increases and the volume of the second region decreases.

20. The method of claim 19, comprising: A flow limiter is provided in the first region of the fluid chamber; as well as The flow limiter is used to restrict the flow rate of fluid flowing from the first region through the orifice to the second region as the pin moves from the latched position to the unlocked position, relative to the flow rate of fluid flowing from the second region through the orifice to the first region as the pin moves from the unlocked position to the latched position, such that the force acting on the disc due to the fluid flow through the orifice is smaller when the pin moves from the unlocked position to the latched position than when the pin moves from the latched position to the unlocked position.

21. An aircraft comprising: The area that the aircraft must temporarily restrict access to; A barrier that can move between a closed position and an open position, wherein in the closed position, access to the area of ​​the aircraft is restricted by the barrier, and in the open position, access to the area of ​​the aircraft is not restricted by the barrier; as well as A time-delay latch for the barrier, the latch comprising: case; A fluid chamber, which is housed within the housing, for retaining fluid within the fluid chamber; A pin extending through the fluid chamber and axially movable within and through the fluid chamber from a latched position to a latched position and from the latched position to a latched position, wherein in the latched position the latch is disengaged from the barrier to allow movement of the barrier, and in the latched position the latch is engaged with the barrier to restrict movement of the barrier; and A release frame, which is movably fixed within the housing; The release frame is configured to engage with the pin when the pin is in the latched position to prevent axial movement of the pin, and to disengage from the pin when the pin is in the unlatched position to allow the axial movement of the pin. Wherein, the axial movement of the pin from the latched position to the unlocked position requires a predetermined duration; and The latch is configured such that the axial movement of the pin from the unlocked position to the latched position occurs faster than the predetermined duration.

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