Patent Description:
This instant specification relates to an aircraft thrust reverser actuation locking system.

Contemporary aircraft engines may include a thrust reverse actuation system to assist in reducing the aircraft speed during landing. Typical thrust reversers include a movable transcowl that, when in the active position, reverses at least a portion of the airflow passing through the engine.

Accidental or inadvertent activation and deployment of thrust reversers at inappropriate times can be dangerous or deadly. Accidental deployment on the ground while ground crews are performing service on the engine can result in injury or death. Accidental activation during flight can cause a catastrophic loss of airspeed or failure of the airframe. Mechanical malfunctions, such as a loss of hydraulic pressure, can also allow a reverser to move out of the stowed position at an inappropriate time.

To prevent accidental or unintentional thrust reverser deployment, locking mechanisms are used. Before the thrust reverser can be moved from its stowed position, the lock must first be disengaged. Some current reverser lock designs implement rotating jaws to engage a probe. Such designs can be heavy and mechanically complex, which adds weight and maintenance requirements to the aircraft on which they are installed.

<CIT> describes a locking device for a translatable air intake structure of a nacelle. A blocking cam passes through a centering pin. The blocking cam is rotated by an electric motor. A bore is formed in the return of a panel. The return supports a retainer. The cam has an unblocking position in which it can be removed from the retainer through the bore. The cam also has a blocking position in which it abuts against the retainer and removal of the cam is prevented.

<CIT> describes a stress absorbing device that includes an actuator equipped with a rod slidably mounted in a hollow body. Two internal and external abutments are attached to the rod and limit its displacement. The first end of the rod is an anchor point and the second has a protrusion. The hollow body includes at least two fingers to grasp and block the protrusion, a slider and, e.g., a motor to translate the slider.

<CIT> describes a retainer member for a locking pin of a thrust reverser system. The pivot pin is shaped to define a pair of projections. The end of a lock member is provided with formations spaced by a distance equal to the width of the pivot pin's projections. A solenoid actuator moves the formations out of cooperation with the projections of the pivot pin-which can then freely move about an axis.

<CIT> describes hinge arms for thrust reverser doors. The hinge arms permit each door to be deployed and retracted. Drive links cooperate with their respective hinge arms. Linear actuators are joined to the drive links.

In general, this document describes an aircraft thrust reverser actuation locking system. The invention is defined in the claims.

In a first aspect, a thrust reverser tertiary lock apparatus according to claims <NUM> to <NUM> is provided.

In a second aspect, a thrust reverser tertiary lock apparatus according to claims <NUM> to <NUM> is provided.

In a third aspect, methods according to claims <NUM> to <NUM> are provided. In a fourth aspect, methods according to claims <NUM> to <NUM> are provided.

The systems and techniques described here may provide one or more of the following advantages. First, the system replaces a conventional two-piece, jaws-type lock mechanism with a much simpler rotary-type design. Second, the system uses a rotary mechanism that is smaller and less complex than the large and heavy moving jaws of jaws-type lock mechanism designs. Third, the system uses a one moving piece mechanism instead of the complex slot and bearing mechanism that is used to swing the jaws of a jaws-type lock. Fourth, the system is lighter and more reliable than jaws-type lock mechanism.

This document describes systems and techniques for reversing aircraft turbine engine airflow. A thrust reverser with at least one movable element, which is movable to and from a reversing position, may be used to change the direction of the bypass airflow. In the reversing position, the movable element may be configured to reverse at least a portion of the bypass airflow.

Locking mechanisms engage the thrust reversers to prevent accidental activation or accidental deployment (e.g., during flight, during ground maintenance operations). The paragraphs below describe a mechanism that provides such locking in an assembly that is relatively lighter and less complex than existing designs.

<FIG> illustrates an example turbofan jet engine assembly <NUM> having a turbine engine <NUM>, a fan assembly <NUM>, and a nacelle <NUM>. Portions of the nacelle <NUM> have been cut away for clarity. The nacelle <NUM> surrounds the turbine engine <NUM> and defines an annular airflow path or annular bypass duct <NUM> through the jet engine assembly <NUM> to define a generally forward-to-aft bypass airflow path as schematically illustrated by the arrow <NUM>. A combustion airflow is schematically illustrated by the arrows <NUM>.

A thrust reverser with at least one movable element, which is movable to and from a reversing position, may be used to change the direction of the bypass airflow. In the reversing position, the movable element may be configured to reverse at least a portion of the bypass airflow. There are several methods of obtaining reverse thrust on turbofan jet engine assemblies. <FIG> schematically illustrates one example of a thrust reverser <NUM> that may be used in the turbofan jet engine assembly <NUM>. The thrust reverser <NUM> includes a movable element <NUM>. The movable element <NUM> has been illustrated as a cowl portion that is capable of axial motion with respect to the forward portion of the nacelle <NUM>. A hydraulic actuator <NUM> may be coupled to the movable element <NUM> to move the movable element <NUM> into and out of the reversing position. In the reversing position, as illustrated, the movable element <NUM> limits the annular bypass area between the movable element <NUM> and the turbine engine <NUM>, it also opens up a portion <NUM> between the movable element <NUM> and the forward portion of the nacelle <NUM> such that the air flow path may be reversed as illustrated by the arrows <NUM>. An optional deflector or flap (also known as a blocker door) <NUM> may be included to aid in directing the airflow path between the movable element <NUM> and the forward portion of the nacelle <NUM>.

<FIG> schematically illustrates an alternative example of a thrust reverser <NUM>. The thrust reverser <NUM> includes a movable element <NUM>. The movable element <NUM> has been illustrated as a deflector, which may be built into a portion of the nacelle <NUM>. A hydraulic actuator <NUM> may be coupled to the movable element <NUM> to move the movable element <NUM> into and out of the reversing position. In the reversing position, shown in phantom and indicated at <NUM>, the movable element <NUM> turns that air outward and forward to reverse its direction as illustrated by the arrows <NUM>. An optional deflector, blocker door, or flap <NUM> may be included to aid in directing the airflow path outward.

In both illustrative examples, the thrust reverser changes the direction of the thrust force. Both the thrust reverser <NUM> and the thrust reverser <NUM> have been described as hydraulically operated systems and a hydraulic actuator has been schematically illustrated. In some embodiments, the thrust reverser <NUM> and/or the thrust reverser <NUM> can be powered by other fluids (e.g., pneumatic), by electro-mechanical actuators, or by any other appropriate power source or actuator type.

<FIG> is a sectional side view of an exemplary thrust reverser tertiary lock system <NUM> in a locked configuration. <FIG> is a sectional side view of the exemplary thrust reverser tertiary lock system <NUM> in an unlocked configuration. In some implementations, the thrust reverser tertiary lock system <NUM> is an apparatus that can be used to lock the example thrust reverser <NUM> or the example thrust reverser <NUM> of <FIG> and <FIG>.

The exemplary system <NUM> includes a probe assembly <NUM> and a receiver assembly <NUM>. The probe assembly <NUM> is configured to be affixed to a structure <NUM>, such as an airframe member or an aircraft engine frame. The receiver assembly <NUM> is configured to be affixed to a structure <NUM>, such as a thrust reverser transcowl slider. In some embodiments, the probe assembly <NUM> can be affixed to the structure <NUM> and the receiver assembly <NUM> can be affixed to the structure <NUM>.

The receiver assembly <NUM> includes a base <NUM> and an affixment point <NUM> affixed to the base <NUM>. The affixment points <NUM> provide bores through which two fasteners <NUM> (e.g., bolts, screws) are passed to removably affix the base to the structure <NUM>.

A housing <NUM> is also affixed to the base <NUM>. The housing <NUM> includes an aperture <NUM> formed in an end wall <NUM>. A cavity <NUM> is defined within the housing <NUM>, and is partly defined by the end wall <NUM>.

Referring now to <FIG>, a front view of the exemplary receiver assembly <NUM> is shown. The aperture <NUM> is a rotationally asymmetrical opening in the end wall <NUM>. For example, if the aperture <NUM> were to be rotated in the plane of <FIG>, the shape of the aperture <NUM> would be different relative to the shape of the aperture <NUM> in its original position. In the illustrated example, the aperture <NUM> is rectangular (e.g., with a length that is greater than its width). In some embodiments, the aperture <NUM> can have other rotationally asymmetrical shapes that can be activated and partly rotated into a position that is asymmetrical relative to its original position (e.g., triangular, oval, trapezoidal, semi-cylindrical, polygonal).

Referring again to <FIG>, the probe assembly <NUM> includes a shaft <NUM> defining a longitudinal axis <NUM>. The shaft <NUM> is rotationally coupled at one end to a rotary actuator <NUM>. The rotary actuator <NUM> is configured to activate and at least partly rotate the shaft <NUM> about the longitudinal axis between an unlocked configuration (e.g., a first rotational position) and a locked configuration (e.g., a second rotational position that is different from the first).

The shaft <NUM> includes a barb <NUM> at its other end, opposite the rotary actuator <NUM>. Referring now to <FIG> is a magnified side view of the probe <NUM> the thrust reverser tertiary lock system <NUM> in an unlocked configuration, and <FIG> is a magnified side view of the probe <NUM> of the thrust reverser tertiary lock system <NUM> in a locked configuration. <FIG> is a magnified end view of the probe <NUM> the thrust reverser tertiary lock system <NUM> in an unlocked configuration, and <FIG> is a magnified end view of the probe <NUM> of the thrust reverser tertiary lock system <NUM> in a locked configuration.

The barb <NUM> is rotationally asymmetrical about the longitudinal axis <NUM>. For example, when the shaft <NUM> is rotated, the orientation of the barb <NUM> can be changed to a position in that is not symmetrical about the longitudinal axis <NUM> relative to its original position. In the illustrated example, the barb <NUM> is rectangular (e.g., with a length that is greater than its width) when viewed end-on, such as shown in <FIG>. In some embodiments, barb <NUM> can have other rotationally asymmetrical shapes that can be partly rotated into a position that is asymmetrical relative to its original position (e.g., triangular, oval, trapezoidal, semi-cylindrical, polygonal).

Referring again to <FIG>, when rotated into the locked configuration, the barb <NUM> mechanically interferes with the end wall <NUM> of the receiver assembly <NUM> and the receiver assembly <NUM> prevents escapement of the probe <NUM>. For example, when the rectangular shape of the barb <NUM> is rotated relative to the shape of the aperture <NUM> (e.g., <NUM> degrees in the illustrated example), the barb <NUM> is retained with in the cavity <NUM>. In such a locked, retained configuration, as shown in the illustrated example of <FIG>, the structure <NUM> is mechanically retained to the structure <NUM> through the system <NUM>. In use, such a locked and retained configuration can be used to lock a moveable portion of a thrust reverser to an engine frame or airframe to prevent inadvertent or accidental deployment of the thrust reverser.

Referring again to <FIG>, when rotated into the unlocked configuration, the barb <NUM> can fit through the aperture <NUM>, which permits escapement of the barb <NUM> from the cavity <NUM> through the end wall <NUM>. In such an unlocked configuration, as shown in the illustrated example of <FIG>, the structure <NUM> is mechanically released from the structure <NUM>. In use, such an unlocked configuration can permit movement of a moveable portion of a thrust reverser relative to an engine frame or airframe, for example, to permit deployment of the thrust reverser.

In some embodiments, the probe <NUM> may be configured to remain in the locked configuration by default. For example, regulatory agencies (e.g., the FAA) may require the system <NUM> to fail "safe" and keep the receiver assembly <NUM> locked to and engaged with the probe <NUM> if power to the rotary actuator <NUM> is lost. In some embodiments, the shaft <NUM> may be biased to the locked configuration by a torsion or linear spring. For example, the rotary actuator <NUM> may include a spring that is configured to urge the probe into the locked configuration. When the rotary actuator <NUM> is energized, the rotary actuator <NUM> overcomes the spring bias to unlock the probe <NUM>. When the rotary actuator <NUM> is de-energized, the spring can urge the probe <NUM> back to the locked configuration.

<FIG> is a side view of an exemplary thrust reverser tertiary lock system <NUM> in a locked configuration while escaped. The system <NUM> is substantially similar to the exemplary thrust reverser tertiary lock system <NUM> of <FIG>, except one or both of a barb <NUM> of a probe <NUM>, and an end wall <NUM> of a receiver <NUM>, are modified relative to the example barb <NUM> and the example end wall <NUM>. The end wall <NUM> will be discussed further in the description of <FIG>, and the barb <NUM> will be discussed further in the description of <FIG>.

In the example system <NUM>, the end wall <NUM> not only prevents escapement of the probe <NUM> from engagement with the receiver assembly <NUM> when locked, without modification the end wall <NUM> can also prevent engagement of the probe <NUM> with the receiver assembly <NUM> (e.g., penetration of the end wall <NUM> by the barb <NUM>) when the probe <NUM> is locked and disengaged from the receiver assembly <NUM>. However, in some implementations (e.g., under some regulatory environments), the system <NUM> may be configured to fail "safe" by permitting the structure <NUM> (e.g., a thrust reverser slider) to reengage and relock with the structure <NUM> (e.g., engine frame) even when the rotary actuator <NUM> has not been energized (e.g., by accident or by malfunction).

The exemplary system <NUM> includes modifications that can permit engagement of the probe <NUM> to the receiver <NUM> when locked and disengaged. For example, the system <NUM> can secure the structure <NUM> to the structure <NUM> even when the rotary actuator <NUM> has not be energized prior to retraction of the structure <NUM> (e.g., somebody forgot to unlock the probe <NUM> prior to retraction, the rotary actuator malfunctions and fails to move the probe <NUM> to the unlocked configuration during retraction).

Similar to the barb <NUM>, the barb <NUM> is rotationally asymmetrical and can be rotated between a locked configuration and an unlocked configuration, and similar to the end wall <NUM>, the end wall includes a rotationally asymmetrical aperture <NUM> that is configured to prevent escapement of the barb <NUM> from the receiver <NUM> in the locked configuration. However, without additional features such as those that will be discussed below, such a configuration can also prevent penetration of the end wall <NUM> by the barb <NUM> while the barb <NUM> is escaped and locked. The barb <NUM> and the end wall <NUM> include features that assist in urging the probe <NUM> from a locked configuration to an unlocked configuration when the receiver <NUM> is moved from an extended position toward a retracted position.

Referring now to <FIG>, a front view of an exemplary receiver <NUM> is shown. The receiver <NUM> is substantially similar to the example receiver assembly <NUM>, except that the end wall <NUM> includes a collection of bevels <NUM>. The bevels <NUM> are configured as a helical or spiral slope that starts at the front face of the end wall <NUM>, and slopes downward and rotationally though a portion of the thickness of the front face <NUM> to the aperture <NUM>. When the receiver <NUM> is moved linearly toward the probe <NUM>, the barb <NUM> contacts a portion of the bevels <NUM>. The bevels <NUM> are configured to convert the linear motion between the receiver <NUM> and the probe <NUM> into rotary motion of the probe <NUM> (e.g., by urging rotation as the barb <NUM> slides down the slope of the bevels <NUM>). In some embodiments, the force of the rotary motion provided by the interaction of the barb <NUM> and the bevels <NUM> can be sufficient to overcome a spring bias that is configured to otherwise urge the barb <NUM> toward the locked configuration.

Eventually, the barb <NUM> is rotated into the unlocked configuration relative to the receiver <NUM>. In the unlocked configuration, the barb <NUM> can continue to penetrate the remainder of the thickness of the end wall <NUM> through the aperture <NUM>. Once the barb has fully penetrated the end face <NUM>, the barb <NUM> can be rotated back to the locked configuration, for example by energizing the rotary actuator <NUM> or by a spring bias configured to urge the barb <NUM> toward the locked configuration (e.g., to reversibly couple the structure <NUM> to the structure <NUM>).

<FIG> are opposing side views of an exemplary barb <NUM> with bevels. In some embodiments, the barb <NUM> can be the example barb <NUM> of <FIG>, or the example barb <NUM> of <FIG>.

The barb <NUM> is substantially similar to the example barb <NUM>, except that the barb <NUM> includes a collection of bevels <NUM>. The bevels <NUM> are configured as an angular, helical, or spiral slope that starts at a major face <NUM> of opposite sides of the barb <NUM>, and slopes downward and rotationally though a portion of the thickness of the barb <NUM>. In some embodiments, the bevels <NUM> can be complementary to the bevels <NUM> of the example receiver <NUM>. In embodiments in which the barb <NUM> is used with the example system <NUM>, when the receiver <NUM> is moved linearly toward the probe <NUM>, the barb <NUM> contacts a portion of the bevels <NUM>. The bevels <NUM> are configured to convert the linear motion between the receiver <NUM> and the probe <NUM> into rotary motion of the probe <NUM> (e.g., by urging rotation as the barb <NUM> slides down the slope of the bevels <NUM>). In some embodiments, the force of the rotary motion provided by the interaction of the barb <NUM> and the bevels <NUM> can be sufficient to overcome a spring bias that is configured to otherwise urge the barb <NUM> toward the locked configuration.

<FIG> is a sectional side view of another exemplary thrust reverser tertiary lock system <NUM> in a locked configuration. <FIG> is a sectional side view of the system <NUM> in an unlocked configuration. In general, the system <NUM> is substantially similar to the example system <NUM> of <FIG>, but with a different barb configuration and receiver configuration. The system <NUM> includes the structure <NUM> and the structure <NUM>, which are releasably linked by a probe <NUM> and a receiver <NUM>.

The probe <NUM> includes the rotary actuator <NUM> and the shaft <NUM>. The probe <NUM> also includes a barb <NUM>. <FIG> are magnified side views of the exemplary barb <NUM> of <FIG> in a locked configuration (e.g., <FIG>) and an unlocked configuration (e.g., <FIG>).

The barb <NUM> includes a base <NUM> that is affixed to the shaft <NUM>. Extending angularly away from the base <NUM> is an arm 1044a and an arm 1044b. The arms 1044a, 1044b are configured to pivot on pivot points <NUM>. A bias member (e.g., spring) (not shown) is configured to bias the arms 1044a, 1044b away from the shaft <NUM>. When a force, greater than the bias force, is applied to the arms 1044a, 1044b, the arms 1044a, 1044b pivot toward a retracted position that is relatively more parallel with the shaft <NUM> than when in their extended, biased position.

The barb <NUM> is rotationally asymmetrical about the longitudinal axis <NUM>. For example, when the shaft <NUM> is rotated, the orientation of the barb <NUM> can be changed to a position in that is not symmetrical about the longitudinal axis <NUM> relative to its original position. In the illustrated example, the arms 1044a, 1044b extend from opposite sides of the based <NUM> a distance that is greater than the thickness of the base <NUM> and shaft <NUM>.

Referring again to <FIG> and <FIG>, when rotated into the locked configuration, the barb <NUM> mechanically interferes with the end wall <NUM> of the receiver <NUM> and the receiver <NUM> prevents escapement of the probe <NUM>. For example, when the arms 1044a, 1044b of the barb <NUM> are rotated relative to the shape of the aperture <NUM> (e.g., <NUM> degrees in the illustrated example), the barb <NUM> is retained with in the cavity <NUM>. In such a locked, retained configuration, as shown in the illustrated example of <FIG>, the structure <NUM> is mechanically retained to the structure <NUM> through the system <NUM>. In use, such a locked and retained configuration can be used to lock a moveable portion of a thrust reverser to an engine frame or airframe to prevent inadvertent or accidental deployment of the thrust reverser.

Referring again to <FIG> and <FIG>, when rotated into the unlocked configuration, the barb <NUM> can fit through the aperture <NUM>, which permits escapement of the barb <NUM> from the cavity <NUM> through the end wall <NUM>. In such an unlocked configuration, as shown in the illustrated example of <FIG>, the structure <NUM> is mechanically released from the structure <NUM>. In use, such an unlocked configuration can permit movement of a moveable portion of a thrust reverser relative to an engine frame or airframe, for example, to permit deployment of the thrust reverser.

In some embodiments, the probe <NUM> may be configured to remain in the locked configuration by default. For example, the shaft <NUM> may be biased to the locked configuration by a spring. When the rotary actuator <NUM> is energized, the rotary actuator <NUM> overcomes the spring bias to unlock the probe <NUM>. When the rotary actuator <NUM> is de-energized, the spring can urge the probe <NUM> back to the locked configuration.

<FIG> is a side view of the exemplary thrust reverser tertiary lock system <NUM> in a locked configuration while escaped. In the example system <NUM>, the end wall <NUM> prevents escapement of the probe <NUM> from engagement the receiver assembly <NUM> when locked. However, in some implementations (e.g., under some regulatory environments), the system <NUM> may be configured to fail "safe" by permitting the structure <NUM> (e.g., a thrust reverser slider) to reengage and relock with the structure <NUM> (e.g., engine frame) even when the rotary actuator <NUM> has not been energized (e.g., by accident or by malfunction).

<FIG> is a zoomed sectional side view of the exemplary thrust reverser tertiary lock system <NUM> of <FIG>. The system <NUM> includes modifications that can permit engagement of the probe <NUM> to the receiver <NUM> when locked and disengaged. For example, the system <NUM> can secure the structure <NUM> to the structure <NUM> even when the rotary actuator <NUM> has not been energized prior to retraction of the structure <NUM> (e.g., somebody forgot to unlock the probe <NUM> prior to retraction, the rotary actuator malfunctions and fails to move the probe <NUM> to the unlocked configuration during retraction).

As discussed above, the barb <NUM> is rotationally asymmetrical and can be rotated between a locked configuration and an unlocked configuration, and the end wall <NUM> includes the rotationally asymmetrical aperture <NUM> that is configured to prevent escapement of the barb <NUM> from the receiver <NUM> in the locked configuration. The arms 1044a, 1044b are configured to permit penetration of the end wall <NUM> by the barb <NUM> while the barb <NUM> is escaped and locked.

By default, the arms 1044a, 1044b are biased away from the shaft <NUM> toward an extended configuration that extends to a size that is relatively larger than the size of the aperture <NUM>. When the arms 1044a, 1044b are folded back toward the shaft, the arms 1044a, 1044b have a retracted size that is relatively smaller than the size of the aperture <NUM>.

As the receiver <NUM> is moved linearly toward the probe <NUM>, the barb <NUM> contacts a portion of the end wall <NUM>. The arms 1044a, 1044b are configured to pivot or otherwise fold inward toward the shaft <NUM> as the barb <NUM> penetrates through the aperture <NUM>. The force of the linear motion is sufficient to overcome the spring bias that is configured to extend the arms 1044a, 1044b toward their extended configuration. With the arms 1044a, 1044b in the smaller, retracted position, the barb <NUM> can fit through the aperture <NUM> even when the probe <NUM> is in the locked configuration. Once the barb <NUM> completely penetrates the end wall <NUM>, the spring bias causes the arms 1044a, 1044b to snap back to their larger, extended positions, which locks the probe <NUM> to the receiver <NUM>.

<FIG> show an example thrust reverser tertiary lock system <NUM>. <FIG> is a zoomed side view of an example probe <NUM> in a locked configuration. <FIG> is a zoomed side view of the probe <NUM> an unlocked configuration. In general, the probe <NUM> is substantially similar to the example probe <NUM> of <FIG>, but includes a barb <NUM> that is actively extendible and retractable instead of, or in addition to, being rotatable.

The probe <NUM> includes a shaft <NUM>. The probe <NUM> also includes a barb <NUM>. The barb <NUM> includes a base <NUM> that is affixed to the shaft <NUM>. Extending angularly away from the base <NUM> is an arm 1444a and an arm 1444b. The arms 1444a, 1444b are configured to pivot relative to the base <NUM>. A pair of linkages <NUM> are pivotably connected at their first ends to the arms 1444a, 1444b, and are pivotably connected at their second ends to an actuation rod <NUM>. The actuation rod <NUM> is coupled to a linear actuator (not shown) configured to urge linear movement of the actuation rod <NUM>. Linear movement of the actuation rod <NUM> (e.g., substantially parallel to the shaft <NUM>) extends and retracts the arms 1444a, 1444b, as will be discussed further below.

Referring to <FIG>, when the actuation rod <NUM> is urged toward the barb <NUM>, as indicated by the arrow <NUM>, the linkages <NUM> push into the arms 1444a and 1444b, urging the arms 1444a, 1444b to pivot, as indicated by the arrows <NUM>, toward an extended position that is relatively larger than the size of the aperture <NUM>. In the extended, locked configuration, the end wall <NUM> mechanically interferes with the barb <NUM> and prevents disengagement of the probe <NUM> from the receiver assembly <NUM>.

Referring to <FIG>, when the actuation rod <NUM> is urged away from the barb <NUM>, as indicated by the arrow <NUM>, the linkages <NUM> pull upon the arms 1444a and 1444b, drawing the arms 1444a, 1444b to pivot, as indicated by the arrows <NUM>, toward a retracted position that is relatively smaller than the size of the aperture <NUM>. In the retracted, unlocked configuration, the end wall <NUM> does not mechanically interferes with the barb <NUM> to prevent disengagement of the probe <NUM> from the receiver assembly <NUM>.

<FIG> is a flow diagram of an example process <NUM> of locking and unlocking a thrust reverser tertiary lock. In some implementations, the process <NUM> can be used with the example thrust reverser tertiary lock system <NUM> of <FIG>, the example thrust reverser tertiary lock system <NUM> of <FIG>, the example thrust reverser tertiary lock system <NUM> of <FIG>, and/or the example thrust reverser tertiary lock system <NUM> of <FIG>.

At <NUM>, a thrust reverser tertiary lock is locked. For example, the thrust reverser tertiary lock system <NUM> can be locked. To lock the lock, several steps are performed.

At <NUM>, a barb at a first end of a shaft of a probe penetrates an aperture defined in an end wall of a receiver shaped to accommodate the barb. For example, the receiver assembly <NUM>, as depicted in <FIG>, can be moved linearly closer to the probe <NUM> until the barb <NUM> penetrates the aperture <NUM>.

At <NUM>, the barb is configured to a first configuration. For example, the probe <NUM> can be reconfigured to the locked configuration as depicted in <FIG>.

At <NUM> escapement of the barb, in the first configuration, though the aperture is prevented by the end wall. For example, if the receiver assembly <NUM> is moved away from the probe <NUM>, the barb <NUM> will be caught by the end wall <NUM> and prevented from escaping. As such, the structure <NUM> will be locked to the structure <NUM>.

In some embodiments, locking the thrust reverser tertiary lock can also include configuring, while in an escaped configuration, the barb to the first configuration, contacting the barb to an edge of the aperture, wherein contact between the barb and the edge urges the barb from the first configuration to the second configuration, penetrating, by the probe, the aperture, and reconfiguring, after the barb has passed through the aperture, the barb to the first configuration. In some embodiments, the barb includes a bevel configured to contact the edge of the aperture and urge rotation of the barb about a primary axis of the shaft from the first configuration to the second configuration during penetration of the aperture by the barb. For example, the barb <NUM> includes the bevels <NUM> that can contact the edges of the aperture <NUM> to urge rotation of the barb <NUM> to permit penetration of the end wall <NUM> by the barb <NUM>. In some embodiments, the edge of the aperture can include a bevel configured to contact the barb and urge rotation of the barb about a primary axis of the shaft from the first configuration to the second configuration during penetration of the aperture by the barb. For example, the end wall <NUM> includes the bevels <NUM> that can urge rotation of the barb <NUM> to permit penetration of the end wall <NUM> by the barb <NUM>.

In some embodiments, reconfiguring, after the barb has passed through the aperture, the barb to the first configuration, can include rotating, by a torsion bias spring, the barb about the axis from the first configuration to the second configuration after the barb has completed penetration of the bevel. For example, the barb <NUM> can be spring-biased by a torsion spring (not shown) connected to the shaft. The rotary actuator <NUM>, the bevels <NUM>, and/or the bevels <NUM> can torque the shaft against the force of the spring, and once the barb <NUM> has passed through the aperture <NUM>, the force of the spring can snap the barb <NUM> into the locked configuration.

In some embodiments, the barb can include an arm having a first end that is pivotably connected to the shaft and configured to contact an edge of the aperture and pivot toward the shaft from the first configuration to the second configuration to pass through the aperture during penetration of the end wall by the barb, and configured to pivot away from the shaft from the second configuration to the first configuration and interfere with escapement of the barb in the first configuration. For example, the barb <NUM> includes the arms 1044a, 1044b that can fold back to permit passage of the barb <NUM> through the aperture <NUM>, and expand to prevent escapement of the barb <NUM> through the end wall <NUM>.

At <NUM>, the thrust reverser tertiary lock is unlocked. For example, the thrust reverser tertiary lock system <NUM> can be unlocked. To unlock the lock, several steps are performed.

At <NUM>, the barb is configured to a second configuration. For example, the barb <NUM> can be reconfigured to the unlocked configuration. In the unlocked configuration, the barb <NUM> can fit through the aperture <NUM>.

At <NUM> escapement of the barb through the aperture in the second configuration is permitted. For example, when the barb <NUM> is in the unlocked configuration and the structure <NUM> is moved linearly away from the structure <NUM>, the barb <NUM> can pass through the aperture <NUM>, allowing the structure <NUM> to be unlocked from the structure <NUM>.

In some embodiments, configuring the barb to the first configuration can include rotating, by a rotary actuator, the barb about an axis from a second rotary position to a first rotary position. For example, the rotary actuator <NUM> or a spring can rotate the barb <NUM> to the unlocked configuration shown in <FIG>, <FIG>.

In some embodiments, configuring the barb to the second configuration can include rotating, by a rotary actuator, the barb about an axis from a first rotary position to a second rotary position. For example, the rotary actuator <NUM> or a spring can urge rotation of the barb <NUM> to the locked configuration shown in <FIG>, <FIG>.

In some embodiments, the barb can have a first size in the first configuration and can have a second size in the second configuration, wherein the second size is smaller than the aperture such that the barb is able to penetrate and escape the aperture in the second configuration, and the first size is larger than the aperture such that the barb is retained by the receiver and escapement of the barb through the aperture is prevented by interference between the barb and the end wall in the first configuration, wherein configuring the barb to the first configuration can include actuating, by a linear actuator, at least one arm linked to the linear actuator, extending, based on the actuating, the arm from the second configuration in which the arm extends from the shaft a first distance to define the first size, to the first configuration in which the arm extends from the shaft a second distance greater than the first distance to define the second size. In some embodiments, the barb can have a first size in the first configuration and has a second size in the second configuration, wherein the second size is smaller than the aperture such that the barb is able to penetrate and escape the aperture in the second configuration, and the first size is larger than the aperture such that the barb is retained by the receiver and escapement of the barb through the aperture is prevented by interference between the barb and the end wall in the first configuration, wherein configuring the barb to the first configuration can include actuating, by a linear actuator, at least one arm linked to the linear actuator, and retracting, based on the actuating, the arm from the first configuration in which the arm extends from the shaft a first distance to define the first size, to the second configuration in which the arm extends from the shaft a second distance less than the first distance to define the second size. For example, the actuation rod <NUM> can be moved linearly by a linear actuator to cause the arms 1444a, 1444b to extend and retract, expanding and shrinking the overall size of the barb <NUM>. In the expanded configuration, the barb <NUM> is too large to be retracted back through the aperture <NUM>. In the retracted configuration, the barb <NUM> is small enough to be escapable from the receiver assembly <NUM> through the aperture <NUM>.

Claim 1:
A thrust reverser tertiary lock apparatus (<NUM>) comprising:
a probe (<NUM>) configured to be affixed to an aircraft engine frame and comprising a shaft (<NUM>) having a barb (<NUM>) at a first end and configurable to a first configuration and a second configuration;
a receiver (<NUM>) configured to be affixed to a thrust reverser transcowl slider or door, said receiver (<NUM>) configured to accommodate the barb (<NUM>) and comprising a housing having an end wall (<NUM>) having an aperture (<NUM>) to a cavity (<NUM>) defined within the housing, the aperture (<NUM>) shaped to permit escapement of the barb (<NUM>) from the cavity (<NUM>) in the first configuration and prevent escapement of the barb (<NUM>) from the cavity in the second configuration, such that the barb (<NUM>) is retained within the cavity (<NUM>) in the second configuration, wherein the aperture (<NUM>) is rotationally asymmetric relative to an axis and the barb (<NUM>) is rotationally asymmetric about the axis between the first configuration and the second configuration, such that the barb (<NUM>) is escapable from the receiver (<NUM>) through the aperture (<NUM>) in the first configuration and the barb (<NUM>) is interfered with by the end wall (<NUM>) such that escapement of the barb (<NUM>) from the cavity (<NUM>) is prevented in the second configuration; and
a rotary actuator (<NUM>) configured to rotate the barb (<NUM>) about the axis, wherein the barb (<NUM>) is rotatable by the rotary actuator (<NUM>) between the first configuration and the second configuration.