Patent Description:
The present disclosure relates to landing gear, and more particularly, to an electrically operated landing gear lock system.

Aircrafts generally include landing gear that supports the aircraft during taxi, take-off, and landing. After take-off, the landing gear may be translated to a "landing gear up" position, wherein the landing gear translates into a wheel well defined by, for example, a wing or a fuselage of the aircraft. A lock assembly may be employed to maintain the landing gear within the wheel well (i.e., in the "landing gear up" position). Current lock assemblies tend to employ hydraulic actuators, which may increase the weight of the lock system and/or the noise associated with locking and unlocking the system. Hydraulic actuators may also be susceptible to hydraulic fluid leakage. <CIT> describes a latch device. <CIT> describes locks such as those for a door. <CIT> describes a rotary pawl latch.

A lock system is disclosed herein and defined in claim <NUM>.

In various embodiments, a radially outward surface of the hook may be oriented at a first angle greater than <NUM>° and less than <NUM>° relative to a first horizontal plane. The first horizontal plane may be coplanar with a radially outward most point of the radially outward surface of the hook and parallel to an axis of rotation of the hook. A radially inward surface of the hook may be oriented at a second angle greater than <NUM>° and less than <NUM>° relative to a second horizontal plane. The second horizontal plane may be coplanar with a radially inward most point of the radially inward surface of the hook and parallel to the axis of rotation of the hook.

In various embodiments, the hook may further comprise a relief surface extending from the radially outward most point of the radially outward surface of the hook. The relief surface may be oriented at an angle of <NUM>° to <NUM>° relative to the first horizontal plane.

In all embodiments, the manual release assembly is configured to translate the lock pin away from the hook. The manual release assembly comprises a release bracket configured to slide relative to the housing and a bracket biasing member configured to bias the release bracket toward the hook. The manual release assembly further comprises a pop-up pin, a pop-up strip, a cord, and a strip biasing member. The pop-up pin includes a head and a pin shaft extending from the head. The head is located over a first surface of the housing and an end of the pin shaft extends from a second surface of the housing opposite the first surface. The pop-up strip is located over the first surface. The cord is coupled to a first end of the pop-up strip and configured to translate a slanted surface of the pop-up strip toward the pop-up pin. The strip biasing member is configured to bias a second end of the pop-up strip away from the pop-up pin.

In various embodiments, a first portion of the cord may be coupled to the pop-up strip and a second portion of the cord may be coupled to the release bracket. In various embodiments, the first portion and the second portion may be connected at a connection point. A first difference between a first length of first portion and a first distance between the connection point and the first end of the pop-up strip may be less than a second difference between a second length of second portion and a second distance between the connection point and the release bracket.

In various embodiments, a centering rod may be located through the hook. A first hook biasing member may be located around the centering rod and configured to bias the hook in a first direction. A second hook biasing member may be located around the centering rod and configured to bias the hook in a second direction opposite the first direction. In various embodiments, a proximity sensor may be configured to detect a position of the lock pin.

A landing gear assembly is also disclosed herein. In accordance with various embodiments, the landing gear assembly may comprise a landing gear configured to rotate about a pivot joint and a lock system according to claim <NUM> configured to engage the landing gear.

In various embodiments, the lock system may further comprise a first proximity sensor configured to detect a position of the lock pin, a second proximity sensor configured to detect a position of the hook, and a controller configured to determine a position of the lock pin based a first signal output from the first proximity sensor and a position of the hook based on a second signal output from the second proximity sensor.

In various embodiments, a first portion of the cord may be coupled to the pop-up strip and a second portion of the cord may be coupled to the release bracket. In various embodiments, the cord may be configured to translate the pop-up pin prior to translating the release bracket.

In various embodiments, the lock system may further comprise a centering rod located through the hook, a first hook biasing member configured to bias the hook in a first direction, and a second hook biasing member configured to bias the hook in a second direction opposite the first direction.

A lock system is also disclosed herein. In accordance with various embodiments, the lock system may comprise a housing and a hook configured to rotate relative to the housing. A lock pin may be configured to translate into a rotational path of the hook. An actuator may be configured to translate the lock pin. A manual release assembly may be configured to translate the lock pin away from the hook.

In various embodiments, the manual release assembly may comprise a release bracket configured to slide relative to the housing, a bracket biasing member configured to bias the release bracket toward the hook, and a pop-up pin including a head and a pin shaft extending from the head. The head may be located over a first surface of the housing and an end of the pin shaft extends from a second surface of the housing opposite the first surface. The manual release assembly may further comprise a pop-up strip located over the first surface, a cord coupled to a first end of the pop-up strip and configured to translate a slanted surface of the pop-up strip toward the pop-up pin, and a strip biasing member configured to bias a second end of the pop-up strip away from the pop-up pin.

In various embodiments, a centering rod may be located through the hook. A first hook biasing member configured to bias the hook in a first direction. A second hook biasing member may be configured to bias the hook in a second direction opposite the first direction.

In various embodiments, a first sensor may be configured to detect a position of the lock pin. A second sensor may be configured to detect a position of the hook. A controller may be configured to determine a position of the lock pin based a first signal output from the first sensor and a position of the hook based on a second signal output from the second sensor.

The detailed description of exemplary embodiments herein makes reference to the accompanying drawings, which show exemplary embodiments by way of illustration. While these exemplary embodiments are described in sufficient detail to enable those skilled in the art to practice the disclosure, it should be understood that other embodiments may be realized and that logical changes and adaptations in design and construction may be made in accordance with this disclosure and the teachings herein without departing from the scope of the disclosure, as defined by the appended claims.

Also, any reference to attached, fixed, connected or the like may include permanent, removable, temporary, partial, full, and/or any other possible attachment option. Surface cross hatching lines may be used throughout the figures to denote different parts but not necessarily to denote the same or different materials.

Surface shading and/or cross hatching lines may be used throughout the figures to denote different parts but not necessarily to denote the same or different materials. Throughout the present disclosure, like reference numbers denote like elements. Accordingly, elements with like element numbering may be shown in the figures, but may not be necessarily repeated herein for the sake of clarity.

A first component that is "radially outward" of a second component means that the first component is positioned a greater distance away from a common axis of the first and second components as compared to the second component. A first component that is "radially inward" of a second component means that the first component is positioned closer to a common axis of the first and second components than the second component. As used herein, "distal" refers to a direction outward, or generally, away from a reference component. As used herein, "proximate" refers to a direction toward, or generally, closer to the reference component.

With reference to <FIG>, an aircraft <NUM> is illustrated, in accordance with various embodiments. Aircraft <NUM> may include a fuselage <NUM> and wings <NUM>. Aircraft <NUM> may further include landing gear such as landing gear assembly <NUM>, landing gear assembly <NUM>, and landing gear assembly <NUM>. Landing gear assembly <NUM>, landing gear assembly <NUM>, and landing gear assembly <NUM> may generally support aircraft <NUM>, when aircraft is not flying, allowing aircraft <NUM> to taxi, take off, and land without damage.

Landing gear assemblies <NUM>, <NUM>, <NUM> may each include various shock and strut assemblies with one or more wheels attached thereto. Landing gear assemblies <NUM>, <NUM>, <NUM> may each be configured to translate between a landing gear down position, wherein the landing gear extend from wings <NUM> and/or from fuselage <NUM> to support aircraft <NUM>, and a landing gear up position, wherein the landing gear are located within wings <NUM> and/or fuselage <NUM> of aircraft <NUM>. For example, during taxiing, take-off, and landing, landing gear assemblies <NUM>, <NUM>, <NUM> may be in the landing gear down position. After take-off, landing gear assemblies <NUM>, <NUM>, <NUM> may be translated to the landing gear up position. Prior to landing, landing gear assemblies <NUM>, <NUM>, <NUM> may be translated to the landing gear down position to support aircraft <NUM> during landing.

It may be desirable to secure landing gear assemblies <NUM>, <NUM>, <NUM> in the up position during flight. In this regard, a landing gear lock system, as disclosed herein, is configured to maintain each of landing gear assemblies <NUM>, <NUM>, <NUM> in the landing gear up position. In accordance with various embodiments, the landing gear lock system may include a rotating hook configured engage the landing gear in the up position. The lock system may include an electromechanical actuator configured to linearly translate a lock pin configured to restrict rotation of the hook, thereby locking the landing gear in the landing gear up position. In various embodiments, the lock system may include a manual release assembly configured to translate the lock pin, and providing a redundancy should the electromechanical actuator malfunction.

With reference to <FIG>, landing gear assembly <NUM> is illustrated in the landing gear down position. In accordance with various embodiments, landing gear assembly <NUM> includes a landing gear <NUM> configured to rotate about a pivot joint <NUM>. A retract actuator <NUM> is operationally coupled to landing gear <NUM>. Retract actuator <NUM> is configured to rotate landing gear <NUM> about pivot joint <NUM>. Retract actuator <NUM> is configured to rotate landing gear <NUM> between the landing gear up and landing gear down positions. Landing gear <NUM> may be configured to retract into a wheel well <NUM>. In this regard, in the landing gear up position (<FIG>), landing gear <NUM> may be located within wheel well <NUM>. Wheel well <NUM> is defined by an aircraft structure <NUM>. Aircraft structure <NUM> may be, for example, a portion of wing <NUM> or fuselage <NUM> in <FIG>.

A lock system <NUM> of landing gear assembly <NUM> may be located within wheel well <NUM>. <FIG>, <FIG>, and <FIG> illustrate a cross-section view of lock system taken along the line 2A-2A in <FIG>. Lock system <NUM> is configured to engage and maintain landing gear <NUM> in the landing gear up position. In various embodiments, landing gear <NUM> includes an uplock roller <NUM>. Uplock roller <NUM> may extend between a pair of lugs <NUM>. Uplock roller <NUM> may be configured to rotate, or spin, relative to lugs <NUM>. Uplock roller <NUM> is spaced apart from a strut cylinder <NUM> of landing gear <NUM>. Uplock roller <NUM>, lugs <NUM>, and strut cylinder <NUM> define a volume <NUM> configured to receive a hook <NUM> of lock system <NUM>.

With reference to <FIG>, as landing gear <NUM> rotates to the landing gear up position, retract actuator <NUM> causes landing gear <NUM> to rotate circumferentially about pivot joint <NUM> in a first direction <NUM>. As landing gear <NUM> rotates circumferentially in the first direction <NUM>, landing gear <NUM> contacts hook <NUM> of lock system <NUM>. Hook <NUM> is positioned such that a radially outward surface <NUM> of hook <NUM> is in the path <NUM> of uplock roller <NUM>. As landing gear <NUM> rotates circumferentially in first direction <NUM>, uplock roller <NUM> contacts radially outward (or first) surface <NUM> of hook <NUM>. In accordance with various embodiments, when landing gear <NUM> rotates from the landing gear down position to the landing gear up position, lock system <NUM> is in an unlocked state. As described in further detail below, in the unlocked state, hook <NUM> of lock system <NUM> is free, or otherwise allowed, to rotate about a shaft <NUM> of lock system <NUM>.

In accordance with various embodiments, the contact between uplock roller <NUM> of landing gear <NUM> and radially outward surface <NUM> of hook <NUM> forces hook <NUM> away from uplock roller <NUM>. In this regard, the contact between uplock roller <NUM> and radially outward surface <NUM> of hook <NUM> causes hook <NUM> to rotate circumferentially about shaft <NUM> in a first direction <NUM>. With momentary reference to <FIG>, in various embodiments, radially outward surface <NUM> of hook <NUM> may be oriented at an angle relative to a first horizontal plane <NUM>. For example, radially outward surface <NUM> may be oriented at angle theta (θ) relative to first horizontal plane <NUM>. Angle theta (θ) may be greater than <NUM>° and less than <NUM>°. In various embodiments, angle theta (θ) may be between <NUM>° and <NUM>°, between <NUM>° and <NUM>°, or about <NUM>°, wherein in the previous context only, "about" means ± <NUM>°. Angle theta (θ) may facilitate translation of hook <NUM> in first direction <NUM> in response to contact between uplock roller <NUM> and radially outward surface <NUM>. First horizontal plane <NUM> may be coplanar with the radially outward most point <NUM> of radially outward surface <NUM> (i.e., the point of radially outward surface <NUM> that is farthest from shaft <NUM> and aperture <NUM>). First horizontal plane <NUM> is parallel to the plane of the axis of rotation of hook <NUM> (i.e., first horizontal plane <NUM> is parallel to the XZ plane in the provided XYZ axes).

With reference to <FIG>, in accordance with various embodiments, hook <NUM> is biased such that, in response to the interference between hook <NUM> and uplock roller <NUM> being removed, hook <NUM> rotates circumferentially about shaft <NUM> in a second direction <NUM>. Second direction <NUM> is opposite first direction <NUM>. In this regard, hook <NUM> rotates into volume <NUM>, in response to uplock roller <NUM> being located radially inward of a radially inward (or second) surface <NUM> of hook <NUM>. Radially inward surface <NUM> is oriented generally toward the axis of rotation of hook <NUM>. Radially outward surface <NUM> of hook <NUM> is oriented generally away from the axis of rotation of hook <NUM>.

In response to hook <NUM> being located in volume <NUM> (i.e., located radially outward of uplock roller <NUM>), lock system <NUM> is translated to the locked state. <FIG> illustrates a cross-section view of lock system <NUM> in the locked state taken along the line 2C-2C in <FIG>. As described in further detail below, in the locked state, a lock pin <NUM> of lock system <NUM> blocks, or otherwise prevents, hook <NUM> from rotating circumferentially in first direction <NUM>. In response to lock system <NUM> be placed in the locked state, retract actuator <NUM> is switch to an off state. In the off state, retract actuator <NUM> does not support the load of landing gear <NUM>. In this regard, in response to retract actuator <NUM> being in the off state, gravity forces landing gear <NUM> to rotate circumferentially about pivot joint <NUM> in a second direction <NUM>. Second direction <NUM> is opposite first direction <NUM>. The gravitational forces acting on landing gear <NUM> cause uplock roller <NUM> to contact radially inward surface <NUM> of hook <NUM>. When lock system <NUM> in the locked state and retract actuator <NUM> is in the off state, the load of landing gear <NUM> is transferred through hook <NUM>, shaft <NUM>, and lock pin <NUM> to a housing <NUM> of lock system <NUM>. Housing <NUM> may be coupled to, installed on, or otherwise attached to aircraft structure <NUM>. In this regard, in the landing gear up position with lock system <NUM> in the locked state and retract actuator <NUM> in the off state, the load of landing gear <NUM> may be transferred via housing <NUM> of lock system <NUM> to aircraft structure <NUM>.

In accordance with various embodiments, retract actuator <NUM> may be switched to an on state, in response to receiving a landing gear down command from, for example, the cockpit. The landing gear down command may cause retract actuator <NUM> to translate landing gear <NUM> circumferentially in first direction <NUM>, thereby removing the load of landing gear <NUM> from hook <NUM>. The landing gear down command from the cockpit also causes an unlock command to be sent to lock system <NUM>. The unlock command causes lock system <NUM> to translate lock pin <NUM> out the path of hook <NUM>. In response to lock system <NUM> translating to the unlocked state, retract actuator <NUM> causes landing gear <NUM> to rotate circumferentially about pivot joint <NUM> in second direction <NUM>.

With reference to <FIG>, as landing gear <NUM> rotates circumferentially in second direction <NUM>, uplock roller <NUM> of landing gear <NUM> contacts radially inward surface <NUM> of hook <NUM>. The contact between uplock roller <NUM> of landing gear <NUM> and radially inward surface <NUM> of hook <NUM> forces hook <NUM> away from uplock roller <NUM>. In this regard, the contact between uplock roller <NUM> and radially inward surface <NUM> causes hook <NUM> to rotate in a circumferentially about shaft <NUM> in a first direction <NUM>. Hook <NUM> rotates circumferentially in first direction <NUM> until the uplock roller <NUM> is located radially outward of radially inward surface <NUM>. In response to uplock roller <NUM> being located radially outward of radially inward surface <NUM> (i.e., in response to hook <NUM> be located outside volume <NUM>), landing gear <NUM> is free to rotate out wheel well <NUM> and to the landing gear down position shown in <FIG>.

With momentary reference to <FIG>, in various embodiments, radially inward surface <NUM> of hook <NUM> may be oriented at an angle beta (β) relative to a second horizontal plane <NUM>. Angle beta (β) may be greater than <NUM>° and less than <NUM>°. In various embodiments, angle beta (β) may be between <NUM>° and <NUM>°, between <NUM>° and <NUM>°, or about <NUM>°, wherein in the previous context only, "about" means ± <NUM>°. Angle beta (β) may facilitate translation of hook <NUM> in first direction <NUM> in response to contact between uplock roller <NUM> and radially inward surface <NUM>. Second horizontal plane <NUM> may be coplanar with the radially inward most point <NUM> of radially inward surface <NUM> (i.e., the point of radially inward surface <NUM> that is closest to shaft <NUM> and aperture <NUM>). Second horizontal plane <NUM> is parallel to the plane of the axis of rotation of hook <NUM> (i.e., second horizontal plane <NUM> is parallel to the XZ plane in the provided XYZ axes).

In accordance with various embodiments, hook <NUM> is biased such that, in response to the interference between hook <NUM> and uplock roller <NUM> being removed, hook <NUM> rotates circumferentially about shaft <NUM> in second direction <NUM>. In this regard, the biasing forces applied to hook <NUM> are configured to locate, or "re-center", hook <NUM> in the path <NUM> of uplock roller <NUM> such that hook <NUM> is in position for the next time landing gear <NUM> is translated to the landing gear up position.

While <FIG>, <FIG>, <FIG>, and <FIG> illustrate lock system <NUM> engaging landing gear <NUM> of landing gear assembly <NUM>, it is further contemplated and understood that landing gear assembly <NUM> and landing gear assembly <NUM>, with momentary reference to <FIG>, may include landing gears, similar to landing gear <NUM>, which may be secured by a lock system including the elements and functionalities as described herein with respect to lock system <NUM>.

With reference to <FIG> and <FIG>, a lock system <NUM> for locking aircraft landing gear in the landing gear up position is illustrated. In accordance with various embodiments, lock system <NUM> includes housing <NUM>, hook <NUM>, and shaft <NUM>. Shaft <NUM> may be coupled to housing <NUM>. Hook <NUM> is configured to rotate about shaft <NUM> and relative to housing <NUM>.

Lock system <NUM> further includes lock pin <NUM> and a lock actuator <NUM>. Lock actuator <NUM> is configured to translate lock pin <NUM> toward and away from hook <NUM>. Lock actuator <NUM> may translate lock pin <NUM> in a linear direction. With additional reference to <FIG>, in various embodiments, a piston <NUM> of lock actuator <NUM> is coupled, for example, via a threaded coupling, a cross bolt, or any other suitable fastening, to lock pin <NUM>. In accordance with various embodiments, lock actuator <NUM> is an electromechanical actuator. In this regard, lock actuator <NUM> is configured to translate piston <NUM>, and thus lock pin <NUM> which is coupled to piston <NUM>, in response to receiving an electrical signal from a controller <NUM>. In various embodiments, power is provided to lock actuator <NUM> via electrical conduits <NUM>. Electrical conduits <NUM> may also electrically couple controller <NUM> and lock actuator <NUM>. In various embodiments, lock actuator <NUM> may receive power from an aircraft and/or landing gear power supply. In various embodiments, lock system <NUM> may include a backup battery <NUM>. Backup battery <NUM> is electrically coupled to lock actuator <NUM>. In various embodiments, backup battery may be electrically coupled to electrical conduits <NUM>. In various embodiments, backup battery <NUM> may be mounted to a release bracket <NUM> of lock system <NUM>. In various embodiments, backup battery <NUM> may comprise, for example, a rechargeable lithium battery. Backup battery <NUM> may provide to power to lock actuator should lock actuator <NUM> fail to receive power from its normal power supply (e.g., from the aircraft or landing gear power supply).

With continued reference to <FIG>, controller <NUM> is operationally coupled to and may control actuation of lock pin <NUM>. Controller <NUM> may comprise a processor and a tangible, non-transitory memory <NUM>. The processor can be a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or a combination thereof. As used herein, the term "non-transitory" is to be understood to remove only propagating transitory signals per se from the claim scope and does not relinquish rights to all standard computer-readable media that are not only propagating transitory signals per se. Stated another way, the meaning of the term "non-transitory computer-readable medium" and "non-transitory computer-readable storage medium" should be construed to exclude only those types of transitory computer-readable media which were found in In re Nuijten to fall outside the scope of patentable subject matter under <NUM> U.

Controller <NUM> may be a standalone controller or may be incorporated into an overall control for landing gear <NUM>. Controller <NUM> may comprise one or more logic modules that implement landing gear logic. Controller <NUM> may be operationally coupled to a display <NUM>. Display <NUM> may be located in the cockpit and may convey information regarding the status of lock system <NUM> to the pilot. For example, display <NUM> may convey whether lock system <NUM> is in the locked state or the unlocked state.

With combined reference to <FIG> and <FIG>, in various embodiments, lock system <NUM> includes one or more sensors, such as sensor <NUM> and sensor <NUM>. Sensors <NUM>, <NUM> are proximity sensors configured to determine a location of lock pin <NUM> and hook <NUM>. For example, sensors <NUM>, <NUM> may be inductive, capacitive, magnetic, optical, or any other suitable type of proximity sensor. Sensors <NUM>, <NUM> may be mounted to housing <NUM>. Sensors <NUM>, <NUM> are operationally coupled, via wired or wireless connection, to controller <NUM>. Stated differently, sensors <NUM>, <NUM> may output signals, indicative of the position of lock pin <NUM> and hook <NUM>, to controller <NUM>. In accordance with various embodiments, controller <NUM> is configured to determine the state (i.e., locked or unlocked) of lock system <NUM> and the position of hook <NUM> (e.g., "centered" or "not centered") based on the signals received from sensors <NUM>, <NUM>. In various embodiments, controller <NUM> determines the position of lock pin <NUM> based on signals output from sensor <NUM>, and the position of hook <NUM> based on signals output from sensor <NUM>.

Controller <NUM> may control actuation of landing gear <NUM> in <FIG>, <FIG>, <FIG>, and <FIG>, and/or control action of lock pin <NUM> based actuation of landing gear <NUM>. In this regard, with combined reference to <FIG> and <FIG>, in response to receiving a landing gear up command, controller <NUM> may command retract actuator <NUM> to retract landing gear <NUM> into wheel well <NUM>. Upon determining landing gear <NUM> is in the landing gear up position and hook <NUM> is in the "centered" position, controller <NUM> commands lock actuator <NUM> to actuate lock pin <NUM> toward hook <NUM>. In response to determining lock system <NUM> is in the locked state (e.g., based upon output from sensors <NUM>, <NUM>), controller <NUM> commands display <NUM> to indicate landing gear <NUM> is up and locked, thereby indicating that the retract actuator <NUM> can be switched to the off state. In response to receiving a landing gear down command, retract actuator <NUM> is switched to the on state and controller <NUM> commands lock actuator <NUM> to translate lock pin <NUM> away from hook <NUM>. In response to determining lock pin <NUM> is not in the path of hook <NUM>, for example, based on signals received from sensors <NUM>, <NUM>, controller <NUM> commands display <NUM> to indicate the landing gear is unlocked. In response to determining lock system <NUM> is in the unlocked state, retract actuator <NUM> is commanded to translate landing gear <NUM> to the landing gear down position. As discussed in further detail below, lock system <NUM> includes a manual release assembly <NUM>. Manual release assembly <NUM> is configured to translate lock system <NUM> to the unlocked stated. For example, if after commanding lock actuator <NUM> to translate lock pin <NUM> away from hook <NUM>, sensors <NUM>, <NUM> indicate lock pin <NUM> is still in the path of hook <NUM>, display <NUM> will continuing displaying that the landing gear locked, thus indicating to the pilot that the manual release assembly <NUM> should be engaged to translate lock system <NUM> to the unlocked state.

With reference to <FIG>, lock system <NUM> is illustrated in the locked stated. In the locked state, lock pin <NUM> is positioned to block, or otherwise prevent, rotation of hook <NUM> circumferentially in first direction <NUM>. Lock pin <NUM> may extend through a wall <NUM> of housing <NUM>. Stated differently, wall <NUM> may define an aperture <NUM> configured to receive lock pin <NUM>. In accordance with various embodiments, lock system <NUM> may further include a centering rod <NUM>, hook biasing members <NUM>, <NUM>, and bushings <NUM>, <NUM>. Hook biasing members <NUM>, <NUM> may comprise compression springs, tension springs, or any other biasing device capable of applying force to hook <NUM> in opposing directions. Centering rod <NUM> extends through an aperture <NUM> defined by hook <NUM>. Centering rod <NUM> may be mounted to housing <NUM>. In various embodiments, centering rod <NUM> is perpendicular to shaft <NUM>. Hook biasing members <NUM>, <NUM> and bushings <NUM>, <NUM> may be located on or around centering rod <NUM>. In various embodiments, hook biasing member <NUM> may be a compression spring, which may be compressed between a wall <NUM> of housing <NUM> and bushing <NUM>. In various embodiments, hook biasing member <NUM> may be a compression spring, which may be compressed between a wall <NUM> of housing <NUM> and bushing <NUM>. Bushings <NUM>, <NUM> may be in contact with opposing sides of hook <NUM>. In accordance with various embodiments, hook <NUM> is biased to a "center" position. In this regard, hook <NUM> may be biased in opposing directions by hook biasing member <NUM> and hook biasing member <NUM>. With momentary combined reference to <FIG> and <FIG>, controller <NUM> may be configured to determine whether hook <NUM> is in the centered position (i.e., in the path <NUM> of uplock roller <NUM> in <FIG>) based on the signals output from sensors <NUM>, <NUM>.

With reference to <FIG>, hook <NUM> is illustrated. In accordance with various embodiments, hook <NUM> defines aperture <NUM> and an aperture <NUM>. Aperture <NUM> is configured to receive centering rod <NUM> (<FIG>). Aperture <NUM> has an elliptical or oval shape. For example, aperture <NUM> may be defined by two parallel walls, which are connected by two rounded, or curved, walls. The shape of aperture <NUM> allows hook <NUM> to pivot, or swing, relative to centering rod <NUM>, in response to rotation of hook <NUM> about shaft <NUM> (<FIG>). Aperture <NUM> is configured to receive shaft <NUM> (<FIG>). Aperture <NUM> has generally circular shape. In various embodiments, one or more grooves <NUM> may be formed in hook <NUM>. Grooves <NUM> may decrease a weight of hook <NUM>. Apertures <NUM>, <NUM> are formed completely through hook <NUM>. Grooves <NUM> are formed only partially through hook <NUM>.

Returning to <FIG>, in accordance with various embodiments, lock system <NUM> includes a manual release assembly <NUM>. Manual release assembly <NUM> is configured to allow lock system <NUM> to be manually translated to the non-locked state from the cockpit by, for example, the pilot. Manual release assembly <NUM> includes a release bracket <NUM>. Release bracket <NUM> is configured to translate relative to housing <NUM>. Release bracket <NUM> may be slidably coupled to support shafts <NUM>, <NUM>. Support shafts <NUM>, <NUM> are coupled to housing <NUM>. For example, support shaft <NUM> may be mounted between wall <NUM> and a wall <NUM> of housing <NUM>. Support shaft <NUM> may be mounted between wall <NUM> and a wall <NUM> of housing <NUM>.

Manual release assembly <NUM> further includes one or more bracket biasing member(s), for example, bracket biasing member <NUM> and bracket biasing member <NUM>, configured to bias release bracket <NUM> toward wall <NUM>. In various embodiments, bracket biasing member <NUM> may be located around support shaft <NUM>. In various embodiments, bracket biasing member <NUM> may be located around support shaft <NUM>. Bracket biasing members <NUM>, <NUM> may comprise compression springs, tension springs, or any other biasing device capable of applying forcing release bracket <NUM> toward wall <NUM>. In various embodiments, bracket biasing member <NUM> may be a compression spring, which may be compressed between a wall <NUM> of release bracket <NUM> and wall <NUM> of housing <NUM>. In various embodiments, bracket biasing member <NUM> may be a compression spring, which may be compressed between wall <NUM> of release bracket <NUM> and wall <NUM> of housing <NUM>. In various embodiments, release bracket <NUM> includes a bulkhead <NUM>. Bulkhead <NUM> may be located between wall <NUM> of release bracket <NUM> and lock actuator <NUM>. In accordance with various embodiments, lock actuator <NUM> (and thus lock pin <NUM>) is coupled to release bracket <NUM>. For example, with reference to <FIG> and <FIG>, a coupling bracket <NUM> may attach lock actuator <NUM> to bulkhead <NUM>. Piston <NUM> of lock actuator <NUM> may translate linearly relative to bulkhead <NUM> and coupling bracket <NUM>.

With continued reference to <FIG>, in accordance with various embodiments, lock pin <NUM> may define a pin groove <NUM>. Pin groove <NUM> is configured to receive a protrusion <NUM> defined by wall <NUM> of release bracket. Locating protrusion <NUM> in pin groove <NUM> may reduce or prevent rotation of lock pin <NUM>. In various embodiments, wall <NUM> of housing <NUM>, with momentary reference to <FIG> may define a protrusion, similar to protrusion <NUM>, configured to be located within pin groove <NUM>.

Returning to <FIG>, manual release assembly <NUM> further includes a cord <NUM>. Cord <NUM> is coupled to release bracket <NUM>. In various embodiments, cord <NUM> is coupled to release bracket <NUM> via a loop or eye end <NUM> attached to release bracket <NUM>. Referring now to <FIG>, and with continued reference to <FIG>, an underside surface <NUM> of housing <NUM> is illustrated. The manual release assembly <NUM> further includes a pop-up strip <NUM>. Pop-up strip <NUM> is located in a channel <NUM> defined by housing <NUM>. Cord <NUM> is coupled to pop-up strip <NUM>. The manual release assembly <NUM> includes a strip biasing member <NUM> configured to bias pop-up strip <NUM> away from cord <NUM> and toward a surface <NUM> of housing <NUM>. Strip biasing member <NUM> may comprise a compression spring, tension spring, or any other biasing device capable of forcing pop-up strip <NUM> away from cord <NUM> and toward a surface <NUM> of housing <NUM>.

With additional reference to <FIG>, cord <NUM> is attached to a first end <NUM> of pop-up strip <NUM> and strip biasing member <NUM> is attached to a second end <NUM> of pop-up strip <NUM> that is opposite first end <NUM>. In various embodiments, strip biasing member <NUM> may be a tension spring, which may be coupled between second end <NUM> of pop-up strip <NUM> and housing <NUM>.

In various embodiments, second end <NUM> of pop-up strip <NUM> may include a flange <NUM>. Flange <NUM> may include a first vertical portion 243a and a horizontal portion 243b. First vertical portion 243a may extending away from a surface <NUM> of pop-up strip <NUM>. Horizontal portion 243b may extend from first vertical portion 243a away from surface <NUM> of housing <NUM>. In various embodiments, first vertical portion 243a may be normal to surface <NUM>, and horizontal portion 243b may be normal to first vertical portion 243a. In various embodiments, flange <NUM> may include a second vertical portion 243c. Second vertical portion 243c may extend from horizontal portion 243b towards surface <NUM>. Second vertical portion 243c may be normal to horizontal portion 243b and/or parallel to first vertical portion 243a. Flange <NUM> may facilitate translation of pop-up strip <NUM> within channel <NUM>. For example, a height <NUM> of pop-up strip <NUM> may be approximately equal to a height <NUM> of channel <NUM>, with momentary reference to <FIG>. Height <NUM> is measured between horizontal portion 243b and surface <NUM> of pop-up strip <NUM> at second end <NUM> of pop-up strip <NUM>. With reference to <FIG>, height <NUM> is measured between a surface <NUM> and a surface <NUM> of housing <NUM>. Surface <NUM> and surface <NUM> may, at least partially, define channel <NUM>. Height <NUM> and height <NUM> being approximately equal tends to prevent or reduce pivoting of pop-up strip <NUM> within channel <NUM>.

Returning to <FIG>, cord <NUM> is configured to translate pop-up strip <NUM> and release bracket <NUM>. In various embodiments, a first portion <NUM> of cord <NUM> is connected to pop-up strip <NUM> and a second portion <NUM> of cord <NUM> is connected to release bracket <NUM>. First portion <NUM> and second portion <NUM> may be connected to one another at a connection point <NUM>. First portion <NUM> extends from connection point <NUM> to pop-up strip <NUM>. Second portion <NUM> extends from connection point <NUM> to release bracket <NUM>.

An end <NUM> of cord <NUM> is operatively coupled to a lever <NUM>. End <NUM> is opposite connection point <NUM> and first and second portions <NUM>, <NUM>. Lever <NUM> may be located in the cockpit. Actuation of lever <NUM> translates, or "pulls," cord <NUM>, thereby causing cord <NUM> to translate pop-up strip <NUM> and release bracket <NUM>. In various embodiments, cord <NUM> is configured to translate of pop-up strip <NUM> prior to release bracket <NUM>. In various embodiments, a difference between the length of first portion <NUM> and the distance between connection point <NUM> and pop-up strip <NUM> is less than the difference between the length of second portion <NUM> and the distance between connection point <NUM> and release bracket <NUM>. Stated differently, there may be more "slack" in second portion <NUM> as compared to first portion <NUM>. In various embodiments, a length of first portion <NUM> may be less than a length of second portion <NUM>. As discussed in further detail below, translating pop-up strip <NUM> prior to release bracket <NUM>, allows pop-up strip <NUM> to remove a pop-up pin <NUM> from the path of release bracket <NUM>.

Referring to <FIG> and <FIG>, translation of pop-up strip <NUM> is configured to translate a pop-up pin <NUM> of manual release assembly <NUM>. In <FIG>, cord <NUM> has been removed for clarity. With additional reference to <FIG>, pop-up pin <NUM> includes a head <NUM> and a pin shaft <NUM>. Pin shaft <NUM> extends from a surface <NUM> of head <NUM>. In various embodiments, head <NUM> may include a chamfered edge <NUM>. Prior to actuation of lever <NUM> in <FIG>, an end <NUM> of pin shaft <NUM> protrudes from a surface <NUM> of housing <NUM>. Surface <NUM> is opposite surface <NUM>. End <NUM> of pop-up pin <NUM> protruding from surface <NUM> blocks or prevents translation of release bracket <NUM>.

With additional reference to <FIG>, pop-up strip <NUM> is configured to translate pop-up pin <NUM> in a first direction extending from surface <NUM> to surface <NUM> (i.e., in the direction of arrow <NUM>). Pop-up strip <NUM> includes an entry chamfer formed by slanted surfaces <NUM>. Slanted surfaces <NUM> are configured to translate between surface <NUM> of housing <NUM> and surface <NUM> of head <NUM> of pop-up pin <NUM>. Chamfered edge <NUM> of head <NUM> may facilitate head <NUM> sliding over slanted surfaces <NUM> of pop-up strip <NUM>. Surface <NUM> is oriented toward surface <NUM> and surface <NUM> of housing <NUM>, and away from surface <NUM> of housing <NUM>. In various embodiments, surface <NUM> may be parallel to surface <NUM> and surface <NUM>. Pop-up strip <NUM> defines a pin channel <NUM>. Pin channel <NUM> is configured to receive pin shaft <NUM> in response to cord <NUM> translating pop-up strip <NUM> in the direction of arrow <NUM>. A width <NUM> of pin channel <NUM> is less than the diameter of head <NUM> of pop-up pin <NUM> and greater than the diameter of pin shaft <NUM> of pop-up pin <NUM>. Pop-up strip <NUM> is configured such that locating head <NUM> of pop-up pin <NUM> over surface <NUM> of pop-up strip <NUM> translates pin shaft <NUM> into housing <NUM>. In this regard, locating surface <NUM> of pop-up strip <NUM> between surface <NUM> of head <NUM> and surface <NUM> of housing <NUM> translates end <NUM> of pin shaft <NUM> into housing <NUM> (i.e., locates end <NUM> of pin shaft <NUM> between surface <NUM> and surface <NUM>).

Pop-up strip <NUM> is configured to translate pop-up pin <NUM> between an up position <FIG> and a down position <FIG>. In the down position, end <NUM> of pin shaft <NUM> protrudes from surface <NUM> of housing <NUM> and restricts the movement of release bracket <NUM>. During normal operation, pop-up pin <NUM> may be in the down position, thereby locking, or preventing translation of, release bracket <NUM> during normal operation.

In the up position, end <NUM> of pin shaft <NUM> is located within housing <NUM>, such that pin shaft <NUM> is removed from the path of release bracket <NUM>. Pop-up pin <NUM> is translated to the up position by pop-up strip <NUM>. For example, in response to slanted surfaces <NUM> of pop-up strip <NUM> translating towards pop-up pin, slanted surfaces <NUM> contact chamfered edge <NUM> and head <NUM> slides over slanted surfaces <NUM> and then over surface <NUM> of pop-up pin <NUM>, which causes pop-up pin <NUM> to translate in the direction of arrow <NUM>. In this regard, the thickness of pop-up strip <NUM>, as measured between surface <NUM> and surface <NUM>, is selected to remove shaft <NUM> from the path of release bracket <NUM>, thereby allowing second portion <NUM> of cord <NUM> to translate release bracket <NUM> in the direction of arrow <NUM>. Translation of release bracket <NUM> in the direction of arrow <NUM> (i.e., away from wall <NUM> and hook <NUM>) translates lock pin <NUM> in the direction of arrow <NUM>, thereby removing lock pin <NUM> from the rotational path of hook <NUM>.

Thus, should lock actuator <NUM> fail to retract lock pin <NUM> and free hook <NUM> for rotation about shaft <NUM>, pop-up strip <NUM> may be translated by cord <NUM> in response to manual actuation of lever <NUM>, resulting in linear movement of pop-up strip <NUM> towards pop-up pin <NUM>, thereby removing pin shaft <NUM> from the path of release bracket <NUM> prior to cord <NUM> translating release bracket <NUM>.

<FIG> illustrates manual release assembly <NUM> of lock system <NUM> after actuation of lever <NUM>. With combined reference to <FIG> and <FIG>, in accordance with various embodiments, actuation of lever <NUM> translates pop-up strip <NUM> and release bracket <NUM> away from hook <NUM> (i.e., in the direction of arrow <NUM>). Translation of release bracket <NUM> translates lock actuator <NUM> and lock pin <NUM>, which is coupled to piston <NUM> of lock actuator <NUM>, away from hook <NUM>. (i.e., in the direction of arrow <NUM>). Translation of release bracket <NUM>, in response to translation of cord <NUM>, is configured remove lock pin <NUM> from the path of hook <NUM>, such that hook <NUM> can rotate about shaft <NUM>. In this regard, actuation of lever <NUM> translates lock system <NUM> to the unlocked stated.

In accordance with various embodiments, manual release assembly <NUM> is configured to automatically re-set. In this regard, translation of lever <NUM> to its original position creates slack in cord <NUM>, such that the biasing force of bracket biasing members <NUM>, <NUM> and strip biasing member <NUM> is greater than the force applied by cord <NUM>. The biasing force applied by bracket biasing members <NUM>, <NUM> to release bracket <NUM> translates release bracket <NUM>, and thus lock actuator <NUM>, toward wall <NUM> and hook <NUM>. The biasing force applied by strip biasing member <NUM> to pop-up strip <NUM> translates pop-up strip <NUM> toward surface <NUM> and back to its initial position. With combined reference to <FIG>, <FIG>, and <FIG>, translation of pop-up strip <NUM> toward surface <NUM> of housing <NUM> removes surface <NUM> of pop-up strip <NUM> from under head <NUM> of pop-up pin <NUM>, thereby causing head <NUM> to translate toward surface <NUM> and causing end <NUM> of pin shaft <NUM> to extend from surface <NUM> of housing <NUM>. In various embodiments, a portion 247a of surface <NUM> of pop-up strip <NUM> proximate first end <NUM> of pop-up strip <NUM> forces head <NUM> of pop-up pin <NUM> toward surface <NUM> of housing <NUM>. In the down position, the portion 247a of surface <NUM> of pop-up strip <NUM> may be located between head <NUM> and surface <NUM> of housing <NUM>. Translation of pop-up strip <NUM> toward surface <NUM> of housing <NUM> causes pin shaft <NUM> of pop-up pin <NUM> to protrude from surface <NUM> of housing <NUM>, thereby blocking movement of release bracket <NUM>. Thus, manual release assembly <NUM> is configured to automatically re-set such that manual release assembly <NUM> will be in its initial position (<FIG>) the next time the landing gear is translated to the landing gear up position.

Lock system <NUM>, including electromechanical lock actuator <NUM>, may be lighter lock systems employing hydraulic actuators. Further, eliminating hydraulic actuator from the lock system reduces the possibility of hydraulic fluid leaks and may decrease noise levels, during locking and unlocking. Sensors <NUM>, <NUM> in combination with controller <NUM> and display <NUM> allow pilots to quickly and easily determine the state (i.e., locked or unlocked) of the landing gear.

With reference to <FIG>, a hook <NUM> for a landing gear lock system is illustrated. With combined reference to <FIG>, and <FIG>, in various embodiments, hook <NUM> may replace hook <NUM> in lock system <NUM>. Hook <NUM> includes a radially outward surface <NUM> and a radially inward surface <NUM>, which are similar to radially outward surface <NUM> and radially inward surface <NUM>, respectively, of hook <NUM>. Hook <NUM> defines an aperture <NUM> configured to receive shaft <NUM>. Hook <NUM> also defines an aperture configured to receive centering rod <NUM>, similar to aperture <NUM> of hook <NUM> in <FIG>. In various embodiments, one or more grooves <NUM> may be formed in hook <NUM>. Grooves <NUM> may decrease a weight of hook <NUM>. Aperture <NUM> is formed completely through hook <NUM>. Grooves <NUM> may be formed only partially through hook <NUM>.

Radially outward surface <NUM> of hook <NUM> may be oriented at an angle theta (θ) relative to a first horizontal plane <NUM>. Angle theta (θ) may be greater than <NUM>° and less than <NUM>°. In various embodiments, angle theta (θ) may be between <NUM>° and <NUM>°, between <NUM>° and <NUM>°, or about <NUM>°, wherein in the previous context only, "about" means ± <NUM>°. Angle theta (θ) may facilitate translation of hook <NUM> in first direction <NUM> (<FIG>) in response to contact between uplock roller <NUM> and radially outward surface <NUM>. First horizontal plane <NUM> may be coplanar with the radially outward most point <NUM> of radially outward surface <NUM> (i.e., the point of radially outward surface <NUM> that is farthest from shaft <NUM> and aperture <NUM>). First horizontal plane <NUM> is parallel to the plane of the axis of rotation R of hook <NUM> (i.e., first horizontal plane <NUM> is parallel to the XZ plane in the provided XYZ axes).

Radially inward surface <NUM> of hook <NUM> may be oriented at an angle beta (β) relative to a second horizontal plane <NUM>. Angle beta (β) may be greater than <NUM>° and less than <NUM>°. In various embodiments, angle beta (β) may be between <NUM>° and <NUM>°, between <NUM>° and <NUM>°, or about <NUM>°, wherein in the previous context only, "about" means ± <NUM>°. Angle beta (β) may facilitate translation of hook <NUM> in first direction <NUM> (<FIG>) in response to contact between uplock roller <NUM> and radially inward surface <NUM>. Second horizontal plane <NUM> may be coplanar with the radially inward most point <NUM> of radially inward surface <NUM> (i.e., the point of radially inward surface <NUM> that is closest to shaft <NUM> and aperture <NUM>). Second horizontal plane <NUM> is parallel to the plane of the axis of rotation R of hook <NUM> (i.e., second horizontal plane <NUM> is parallel to the XZ plane in the provided XYZ axes).

Hook <NUM> includes a relief surface <NUM> extending from radially outward most point <NUM> of radially outward surface <NUM> and generally away from a tip <NUM> of hook <NUM>. Tip <NUM> may be where radially inward surface <NUM> and radially outward surface <NUM> meet. In various embodiments, relief surface <NUM> may be coplanar with first horizontal plane <NUM>, as shown in <FIG>. In various embodiments, relief surface <NUM> may be oriented at an angle alpha (α) relative to first horizontal plane <NUM> that is greater than <NUM>°, as shown in <FIG>. For example, angle alpha (α) of relief surface <NUM> relative to first horizontal plane <NUM> may be <NUM>° to <NUM>°, <NUM>° to <NUM>°, or about <NUM>°, wherein in the previous context only, "about" means ± <NUM>°. Increasing angle alpha (α) of relief surface <NUM> may decrease a weight of hook <NUM>.

Relief surface <NUM> may decease a radial length L1 of hook <NUM> measured between radially outward most point <NUM> of radially outward surface <NUM> and radially inward most point <NUM> of radially inward surface <NUM>. Decreasing radial length L1 may reduce a weight of hook <NUM>. Decreasing the radial length L1 of hook <NUM> may also allow for shorter lugs <NUM> (<FIG>), as a distance between uplock roller <NUM> and strut cylinder <NUM> may be decreased. Shorter lugs <NUM> tend to reduce an overall weight of landing gear <NUM>.

Claim 1:
A lock system, comprising:
a housing (<NUM>);
a hook (<NUM>) configured to rotate relative to the housing (<NUM>);
a lock pin (<NUM>) configured to translate into a rotational path of the hook (<NUM>);
an actuator (<NUM>) configured to translate the lock pin (<NUM>); and
a manual release assembly (<NUM>) configured to translate the lock pin (<NUM>) away from the hook (<NUM>),
characterised in that the manual release assembly (<NUM>) comprises:
a release bracket (<NUM>) configured to slide relative to the housing (<NUM>);
a bracket biasing member configured to bias the release bracket (<NUM>) toward the hook (<NUM>);
a pop-up pin (<NUM>) including a head (<NUM>) and a pin shaft (<NUM>) extending from the head (<NUM>), wherein the head (<NUM>) is located over a first surface (<NUM>) of the housing (<NUM>) and an end (<NUM>) of the pin shaft (<NUM>) extends from a second surface (<NUM>) of the housing (<NUM>) opposite the first surface (<NUM>);
a pop-up strip (<NUM>) located over the first surface (<NUM>) and configured to translate the pop-up pin (<NUM>) between an up position and a down position, wherein, in the down position, the end (<NUM>) of the pin shaft (<NUM>) protrudes from the second surface (<NUM>) and restricts translation of the release bracket (<NUM>), and wherein, in the up position, the end (<NUM>) of the pin shaft (<NUM>) is located within the housing (<NUM>), such that the pin shaft (<NUM>) is removed from the path of the release bracket (<NUM>) to allow translation of the release bracket (<NUM>) away from the hook (<NUM>), thereby removing the lock pin (<NUM>) from the rotational path of hook (<NUM>);
a cord (<NUM>) coupled to a first end (<NUM>) of the pop-up strip (<NUM>) and configured to translate a slanted surface (<NUM>) of the pop-up strip (<NUM>) toward the pop-up pin (<NUM>); and
a strip biasing member (<NUM>) configured to bias a second end (<NUM>) of the pop-up strip (<NUM>) away from the pop-up pin (<NUM>).