Patent Description:
A modern aircraft propulsion system typically includes a gas turbine engine and a nacelle housing and providing an aerodynamic covering for the gas turbine engine. The nacelle may include one or more cowls for covering components of the gas turbine engine. These cowls may be pivotally mounted to a stationary structure enabling those cowls to be opened for providing access to the components underneath. The cowls may be secured in a closed position using one or more latch assemblies.

Various types and configurations of latch assemblies are known in the art. While these known latch assemblies have various benefits, they are typically difficult and/or time consuming to inspect, replace and/or service. A typical latch assembly, for example, is installed from a backside of a cowl and mechanically fastened to the cowl with one or more mechanical fasteners such as bolts and/or rivets. The latch assembly may be covered with insulation material and/or other components of the nacelle. Therefore, in order to inspect, replace and/or service a typical latch assembly, a technician must first (<NUM>) open the cowl, (<NUM>) remove the insulation and/or other components covering or otherwise hindering access to the latch assembly and (<NUM>) remove the mechanical fasteners securing the latch assembly. There is a need in the art therefore for a latch assembly which can be installed and/or removed from a cowl or other component without requiring access to an interior of the cowl and/or removal of other elements from the cowl.

<CIT> discloses a high visibility latch handle.

<CIT> discloses a pin latch having an intermediate position.

<CIT> discloses a device for indicating incorrect closure of a locking means located between two fan cowlings of an aircraft engine nacelle.

<CIT> discloses an aircraft propulsive power unit.

According to an aspect of the present invention, an assembly is provided for an aircraft in accordance with appended claim <NUM>.

The following optional features may be applied to any of the above aspects.

The second sidewall may be configured with a second slot. The latch pin may be seated in the second slot.

The first slot may have a slot centerline. A first portion of the slot centerline may overlap a second portion of the slot centerline.

The first slot may have a slot centerline. A first portion of the slot centerline may be angularly offset from a second portion of the slot centerline by an acute angle.

A first portion of the first slot may overlap a second portion of the first slot. The first portion of the first slot may be separated from the second portion of the first slot by a projection.

A height of the projection may be greater than one-quarter of a diameter of the latch pin.

The assembly may also include a structure. The latch assembly may also include a keeper connected to the structure. The latch may include a hook configured to mate with the keeper to maintain the cowl in the closed position when the latch is in a closed position.

The assembly may also include nacelle which includes the cowl.

<FIG> illustrates an assembly <NUM> for a structure of an aircraft. An example of the aircraft structure is a nacelle for housing an aircraft propulsion system such as, but not limited to, a gas turbine engine. Another example of the aircraft structure is a fuselage of the aircraft. The assembly <NUM> of the present disclosure, however, is not limited to the foregoing exemplary aircraft structures. Furthermore, the assembly <NUM> is not limited to aircraft applications. For example, the assembly <NUM> and/or its latch assembly described below may be configured with any device and/or system which utilizes a latch for securing a moveable component; e.g., a door or cowl.

The assembly <NUM> of <FIG> includes one or more structures <NUM> and <NUM> and a latch assembly <NUM>. Referring to <FIG>, the first structure <NUM> may be configured as a part of an inner structure <NUM> (sometimes referred to as "an inner fixed structure" or "IFS") of an aircraft propulsion system nacelle <NUM>. The first structure <NUM> of <FIG> and <FIG>, for example, is configured as a first cowl 22A (e.g., an inner fixed cowl) of the nacelle inner structure <NUM>. Referring to <FIG>, the first cowl 22A is movably (e.g., pivotally) connected to a stationary structure (e.g., <NUM>). The first cowl 22A is configured to move (e.g., pivot) between a closed position (see <FIG>) and an open position (see <FIG>). In the closed position, the first cowl 22A is configured to house and provide an aerodynamic covering for one or more components of a gas turbine engine, which components may include one or more components of a core <NUM> of the gas turbine engine. The gas turbine engine core <NUM> includes a compressor section, a combustor section and a turbine section. The first cowl 22A and, more generally, the nacelle inner structure <NUM> also form at least an inner peripheral portion of a flowpath <NUM> (e.g., a bypass flowpath) within the aircraft propulsion system.

The second structure <NUM> may be configured as another part of the nacelle inner structure <NUM>. The second structure <NUM> of <FIG> and <FIG>, for example, is configured as a beam 24A to which the cowls 22A and 22B are latched / secured during propulsion system operation. Fan cowls <NUM> (one shown in <FIG>) and/or outer thrust reverser halves 33A and 33B (generally referred to as "<NUM>") may also be configured to be latched / secured to the beam 24A during propulsion system operation. In one embodiment, the second structure <NUM> / beam 24A of <FIG> and <FIG> also forms side peripheral portions of D-ducts (sometimes also referred to as "C-ducts"), which collectively form at least a portion of the flowpath <NUM>. The present disclosure, however, is not limited to such a D-duct configuration. For example, in other embodiments, the aircraft propulsion system / the assembly <NUM> may be configured with an O-duct.

The latch assembly <NUM> of <FIG> is arranged at an interface <NUM> between the first cowl 22A and the beam 24A. The latch assembly <NUM> is configured to secure the first cowl 22A to the beam 24A in its closed position when the latch assembly <NUM> is in a closed position (see <FIG>). The latch assembly <NUM> is further configured to enable movement of the first cowl 22A when the latch assembly <NUM> is in an open position (see <FIG>).

The latch assembly <NUM> of <FIG> includes a housing assembly <NUM>, a latch <NUM>, a latch pin <NUM> and a keeper <NUM>. The housing assembly <NUM> is configured as a frame and/or mounting structure for the latch <NUM>. The housing assembly <NUM> of <FIG> includes a first housing <NUM> (e.g., U-shaped frame segment) and a second housing <NUM> (e.g., U-shaped frame segment).

The first housing <NUM> is positioned beneath a first skin <NUM> of the first cowl 22A, which first skin <NUM> partially forms a flow surface <NUM> of the nacelle inner structure <NUM> (see also <FIG> and <FIG>). A base <NUM> of the first housing <NUM> is connected to the first cowl 22A. The first housing <NUM>, for example, may be mechanically fastened and/or bonded to a frame on an underside of the first skin <NUM>.

Referring to <FIG> and <FIG>, the first housing <NUM> includes the base <NUM>, an end wall <NUM> and first and second sidewalls 54A and 54B (generally referred to as "<NUM>"). The end wall <NUM> projects vertically out from the base <NUM> (e.g., in a direction towards the first skin <NUM>) to a distal side <NUM> of the first housing <NUM> (see <FIG>). The end wall <NUM> extends laterally between and is connected to the first sidewall 54A and the second sidewall 54B. The first sidewall 54A and the second sidewall 54B each project vertically out from the base <NUM> (e.g., in the direction towards the first skin <NUM>) to the distal side <NUM> of the first housing <NUM> (see <FIG>). The first sidewall 54A and the second sidewall 54B each project longitudinally out from the end wall <NUM> to a distal end <NUM> of the first housing <NUM>. This distal end <NUM> may be substantially aligned with (or slightly recessed from) an edge <NUM> of the first cowl 22A.

Referring to <FIG>, the first sidewall 54A is configured with a (e.g., open ended) first slot 62A. The second sidewall 54B is configured with a (e.g., open ended) second slot 62B.

Referring to <FIG>, each slot 62A, 62B (generally referred to as "<NUM>") may have a hook shape; e.g., each slot <NUM> may be a hooked slot. Each slot <NUM>, for example, may extend along a slot centerline <NUM>. A (e.g., straight) first portion <NUM> of the slot centerline <NUM> may extend substantially vertically into / within the respective sidewall <NUM>. A (e.g., straight) second portion <NUM> of the slot centerline <NUM> may extend vertically and longitudinally within the respective sidewall <NUM>. The second portion <NUM> of the slot centerline <NUM> may thereby be angularly offset from the first portion <NUM> of the slot centerline <NUM> by an acute (e.g., included) angle <NUM>. This angle <NUM> may be between ten degrees (<NUM>°) and sixty degrees (<NUM>°); e.g., between twenty degrees (<NUM>°) and forty degrees (<NUM>°). Of course, in other embodiments, the angle <NUM> may be less than ten degrees (<NUM>°) or greater than sixty degrees (<NUM>°). With this arrangement, the second portion <NUM> of the slot centerline <NUM> (e.g., vertically) overlaps the first portion <NUM> of the slot centerline <NUM>.

Each slot <NUM> of <FIG> includes a first portion <NUM> and a second portion <NUM>. The slot first portion <NUM> is configured as an open portion of the slot <NUM>. The slot first portion <NUM>, for example, extends along the first portion <NUM> of the slot centerline <NUM> (e.g., in a direction away from the first skin <NUM>) into the respective sidewall <NUM> from the distal side <NUM> of the first housing <NUM>. The slot second portion <NUM>, on the other hand, is configured as a blind / closed slot. The slot second portion <NUM>, for example, is coupled with the slot first portion <NUM> at a corner <NUM>. The slot second portion <NUM> extends along the second portion <NUM> of the slot centerline <NUM> (e.g., in a direction towards from the first skin <NUM>) within the respective sidewall <NUM> to a distal closed end <NUM> of the slot <NUM>. This slot second portion <NUM> thereby (e.g., vertically) overlaps the first portion <NUM> of the slot centerline <NUM>. The slot second portion <NUM> is further (e.g., longitudinally) separated from the slot first portion <NUM> by a projection <NUM> formed by a portion of the respective sidewall <NUM> longitudinally between the portions <NUM> and <NUM>.

Referring to <FIG>, each slot <NUM> may extend laterally through the respective sidewall <NUM>.

Referring to <FIG>, the second housing <NUM> is positioned beneath a second skin <NUM> of the beam 24A, which second skin <NUM> partially forms the flow surface <NUM> of the nacelle. A base <NUM> of the second housing <NUM> is connected to the beam 24A. The second housing <NUM>, for example, may be mechanically fastened and/or bonded to a frame on an underside of the second skin <NUM>.

Referring to <FIG> and <FIG>, the second housing <NUM> includes the base <NUM>, an end wall <NUM> and first and second sidewalls 88A and 88B (generally referred to as "<NUM>"). The end wall <NUM> projects vertically out from the base <NUM> (e.g., in a direction towards the second skin <NUM>) to a distal side <NUM> of the second housing <NUM> (see <FIG>). The end wall <NUM> extends laterally between and is connected to the first sidewall 88A and the second sidewall 88B. The first sidewall 88A and the second sidewall 88B each project vertically out from the base <NUM> (e.g., in the direction towards the second skin <NUM>) to the distal side <NUM> of the second housing <NUM> (see <FIG>). The first sidewall 88A and the second sidewall 88B each project longitudinally out from the end wall <NUM> to a distal end <NUM> of the second housing <NUM>. This distal end <NUM> may be substantially aligned with an edge <NUM> of the beam 24A, which edge <NUM> is next to the edge <NUM> of the first cowl 22A at the interface <NUM>.

Referring still to <FIG> and <FIG>, the latch <NUM> is arranged laterally between the sidewalls <NUM>. The latch <NUM> is movably (e.g., pivotally) mounted to the first housing <NUM> by the latch pin <NUM>. Referring to <FIG>, the latch pin <NUM> is seated within a respective one of the slots <NUM>. More particularly, each end of the latch pin <NUM> is seated within a respective one of the slot second portions <NUM>.

Referring to <FIG>, the keeper <NUM> is connected to and extends between the first sidewall 88A and the second sidewall 88B of the second housing <NUM>. Referring to <FIG>, a hook <NUM> of the latch <NUM> is configured to mate with (e.g., hook around) the keeper <NUM> when the latch <NUM> is in its closed position to thereby secure the first cowl 22A to the beam 24A in its closed position.

The latch assembly <NUM> configuration described above enables the latch <NUM> to be removed from the first housing <NUM> while the first housing <NUM> is still connected to the first cowl 22A and while the first cowl 22A is in the closed position. The latch assembly <NUM> configuration described above also or alternatively enables the latch <NUM> to be removed as a cartridge (e.g., a single modular unit) from an exterior of the first cowl 22A without, for example, accessing a back side of the first cowl 22A. For example referring to <FIG>, during installation, the latch pin <NUM> is mated with the latch <NUM> (see <FIG>), and the latch pin <NUM> is translated along the slot centerlines <NUM> through the slots <NUM> from openings to the slots <NUM> to the slot second portions <NUM>. Once the latch pin <NUM> is seated within the slot second portions <NUM>, the latch pin <NUM> mounts the latch <NUM> to the first housing <NUM> (see <FIG> and <FIG>). This process may then be reversed to remove the latch <NUM> from the first housing <NUM>.

Referring still to <FIG>, when the latch <NUM> is mounted to the first housing <NUM>, the latch pin <NUM> may be retained within the slot second portions <NUM> by the respective projection <NUM> while the latch <NUM> is in its open position. When the latch <NUM> is in its closed position, the latch <NUM> pulls the latch pin <NUM> away against the sidewall <NUM> and away from the slot first portions <NUM>.

In some embodiments, the projection <NUM> has a height <NUM>. This height <NUM> may be sized greater than one-quarter (<NUM>/<NUM>) of a diameter <NUM> of the latch pin <NUM>. The height <NUM>, for example, may be between one-quarter (<NUM>/<NUM>) of the diameter <NUM> and the diameter <NUM>; e.g., the height <NUM> may be equal to one-half of the diameter <NUM>. The present disclosure, however, is not limited to the foregoing exemplary embodiments. For example, in other embodiments, the height <NUM> may alternatively be less than one-quarter (<NUM>/<NUM>) of the diameter <NUM> or greater than the diameter <NUM>.

While the latch assembly <NUM> is described above as securing the first cowl 22A to the beam 24A, the present disclosure is not limited to such an exemplary arrangement. For example, in some embodiments, the latch assembly <NUM> (or a second of the latch assemblies <NUM>) may secure the second cowl 22B to the beam 24A. In some embodiments, the latch assembly <NUM> may secure the cowls 22A and 22B directly together where, for example, the beam 24A is omitted. In some embodiments, the latch assembly <NUM> may be configured to secure one of the fan cowls <NUM> or one of the thrust reverser halves <NUM> to the beam 24A or another structure. In some embodiments, the latch assembly <NUM> may be configured to secure the two fan cowls <NUM> together. In some embodiments, the latch assembly <NUM> may be configured to secure the two thrust reverser halves <NUM> together. In some embodiments, the halves <NUM> may be bypass duct halves (or segments) and may be configured without or discrete from a thrust reverser system. The present disclosure therefore is not limited to any particular latch assembly applications.

Claim 1:
An assembly (<NUM>) for an aircraft, comprising:
a cowl (22A) configured to move between an open position and a closed position; and
a latch assembly (<NUM>) including a latch (<NUM>) and a housing (<NUM>), the latch (<NUM>) pivotally mounted to the housing (<NUM>), and the housing (<NUM>) connected to the cowl (22A);
the latch assembly (<NUM>) configured such that the latch (<NUM>) is removable from the housing (<NUM>) while the housing (<NUM>) is connected to the cowl (22A) and the cowl (22A) is in the closed position;
wherein the latch assembly (<NUM>) further includes a latch pin (<NUM>) that pivotally mounts the latch (<NUM>) to the housing (<NUM>), and the latch pin (<NUM>) is removable from the housing (<NUM>) while the housing (<NUM>) is connected to the cowl (22A) and the cowl (22A) is in the closed position;
wherein the housing (<NUM>) includes a first sidewall (54A) and a second sidewall (54B), the first sidewall (54A) is configured with a first slot (62A), the latch (<NUM>) is arranged between the first sidewall (54A) and the second sidewall (54B), and the latch pin (<NUM>) is seated in the first slot (62A),
characterised in that:
the first slot (62A) has a hook shape.