Patent Description:
Latch handles are commonly used in the nacelle of an aircraft, for example, in fan cowls. Fan cowls are hinged to the pylon or to a frame structure attached at the top of the nacelle. Fan cowls enclose the engine fan case and are typically latched with three latches at the bottom of the nacelle. Latch handles secure the fan cowl during flight. Various nacelle components may comprise variations in build tolerances.

<CIT> discloses a latching system for securing two components.

According to an aspect of the present invention, there is a latch hook length adjustment arrangement in accordance with claim <NUM>.

Optionally, the latch hook length adjustment arrangement further comprises an access aperture disposed in the latch hook frame, wherein the adjustment nut is accessible via the access aperture.

Optionally, the first rod aperture is aligned with the second rod aperture.

Optionally, the latch hook length adjustment arrangement further comprises a plurality of adjustment pockets disposed in the radially outer surface of the adjustment nut.

Optionally, an inner diameter of the adjustment nut is less than an inner diameter of the bearing sleeve.

The bearing sleeve is configured to receive the rod.

Optionally, the spring member is configured to receive the rod.

Optionally, the plurality of adjustment pockets are configured to receive a tool for rotating the adjustment nut.

Optionally, the adjustment nut comprises a second side surface disposed opposite the adjustment nut from the first side surface, and the second side surface is substantially smooth.

Optionally, the spring member engages the second side surface.

Optionally, the spring member comprises a wave spring.

Optionally, each detent pocket of the plurality of detent pockets is disposed at an equal distance from an axis of rotation of the adjustment nut.

Optionally, the latch hook length adjustment arrangement further comprises a second rod aperture disposed in the latch hook frame, wherein the second rod aperture is aligned with the first rod aperture, and the second rod aperture is configured to receive the rod, wherein the adjustment nut, the bearing sleeve, and the spring member are disposed between the first rod aperture and the second rod aperture.

Optionally, in response to rotation of the adjustment nut in a first rotational direction with respect to the rod, the rod is configured to move axially with respect to the adjustment nut in a first linear direction.

Optionally, in response to rotation of the adjustment nut in a second rotational direction with respect to the rod, the rod is configured to move axially with respect to the adjustment nut in a second linear direction.

Optionally, the second side surface of the adjustment nut is substantially smooth.

Optionally, each detent pocket of the plurality of detent pockets is sized corresponding to a geometry of the bearing.

The foregoing features, elements, steps, or methods may be combined in various combinations, unless expressly indicated herein otherwise. These features, elements, steps, or methods as well as the operation of the disclosed embodiments will become more apparent in light of the following description and accompanying drawings.

The detailed description of exemplary embodiments herein makes reference to the accompanying drawings, which show exemplary embodiments by way of illustration and their best mode. 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 the detailed description herein is presented for purposes of illustration only and not of limitation. For example, the steps recited in any of the method or process descriptions may be executed in any order and are not necessarily limited to the order presented. Also, any reference to attached, fixed, connected or the like may include permanent, removable, temporary, partial, full and/or any other possible attachment option. Additionally, any reference to "without contact" (or similar phrases) may also include reduced contact or minimal contact.

As used herein, "outward" may define an element or portion of an element that is situated radially outer to or away from another, radially inward, element or portion of an element. Thus, an engine core may be situated radially inward of a fan casing, as described herein. As used herein, "inward" may define the element or portion of the element that is situated radially inward in relation to an outward element.

Aircraft fan cowls are often held together with latch assemblies along various axial distances along the fan case. Fan cases may be encased by two fan cowls, which may be joined together with a latch mechanism (e.g., at the bottom of the fan cowls). For example, a fan cowl may include a latch assembly at the bottom of the fan cowl to allow the fan cowl to be hinged open to facilitate access to various fan case components. Due to build tolerance of the nacelle, it may be desirable to make a latch assembly to be adjustable to fit each individual nacelle and to adjust for geometrical changes of the nacelle over time.

A latch hook length adjustment arrangement of the present disclosure provides convenient and readily accessible adjustment of a length of the latch hook. A latch hook length adjustment arrangement of the present disclosure may provide for adjustment of a length of the latch hook using an existing and common tool.

Referring to <FIG>, a nacelle <NUM> for a gas turbine engine is illustrated according to various embodiments. Nacelle <NUM> may comprise an inlet <NUM>, a fan cowl <NUM>, and a thrust reverser <NUM>. Nacelle <NUM> may be coupled to a pylon <NUM>, which may mount the nacelle <NUM> to an aircraft wing or aircraft body. Nacelle <NUM> may further comprise an exhaust nozzle <NUM>. Nacelle <NUM> surrounds the engine providing smooth aerodynamic surfaces for airflow around and into the engine. Fan cowl <NUM> typically comprises two halves. One half may be referred to as a first fan cowl and the other half may be referred to as a second fan cowl. The first fan cowl and second fan cowl are typically hinged to the pylon or to a frame structure attached at the top of nacelle <NUM>. The nacelle <NUM> may be disposed about a centerline <NUM>, which may also be the axis of rotation of an engine located within the nacelle <NUM>.

With reference to <FIG>, and with continuing reference to <FIG>, a front view of a portion of an engine nacelle with a fan cowl latch handle rotated towards an open position is provided. According to various embodiments, latch handle <NUM> may be included at the bottom of nacelle <NUM>. Latch assemblies typically comprise a latch hook and a latch keeper, wherein the latch hook is actuated by a latch handle located on a flow surface (e.g., an outward portion of the nacelle). Accordingly, in response to the handle being operated, the latch keeper disengages from the latch hook, allowing access to the oil tank, full authority digital engine control (FADEC) box, and other fan case components.

With reference to <FIG>, an outward view of a latch handle assembly <NUM> on a nacelle is provided. According to various embodiments, latch handle assembly <NUM> may include latch housing <NUM> and latch handle <NUM>. Latch housing <NUM> may include a first half <NUM> and a second half <NUM>. First half <NUM> of latch housing <NUM> may be referred to as a keeper housing. First half <NUM> of latch housing <NUM> may be attached to a first cowl <NUM> according to various embodiments. Second half <NUM> of latch housing <NUM> may be attached to a second cowl <NUM> according to various embodiments. According to various embodiments, first cowl <NUM> may be a first fan cowl. According to various embodiments, second cowl <NUM> may be a second fan cowl.

According to various embodiments, latch handle <NUM> may include a first end <NUM> and a second end <NUM>. First end <NUM> may be rotatably coupled to first half <NUM> of latch housing <NUM>. In this regard, second end <NUM> may rotate away from second cowl <NUM> in response to latch handle <NUM> rotating to an open position. According to various embodiments, latch housing <NUM> may be configured to enclose at least a portion of latch handle <NUM> such that the outward surface of latch housing <NUM> and the outward surface of latch handle <NUM> are substantially flush relative to each other when in the closed position. In this manner, latch handle assembly <NUM> may be aerodynamically efficient.

According to various embodiments, latch handle <NUM> may include aperture <NUM>. Aperture <NUM> may be disposed on latch handle <NUM> in order to facilitate the opening of latch handle <NUM>. Typically, the opening of latch handle <NUM> from the closed position is facilitated by inserting an obj ect into aperture <NUM> to depress a release member which may partially release latch handle <NUM> from latch housing <NUM>. The latch handle <NUM> may then be further opened by prying latch handle <NUM> open. However, latch handle arrangements of the present disclosure may be configured to be opened via any suitable method without departing from the scope of the present disclosure.

With reference to <FIG>, a latch assembly <NUM> comprising a latch hook length adjustment arrangement <NUM> is illustrated, in accordance with various embodiments. Latch assembly <NUM> generally comprises a latch hook <NUM> and a latch keeper <NUM>, wherein the latch hook <NUM> is actuated by a latch handle <NUM> located on a flow surface (e.g., an outward portion of a nacelle). With the latch hook <NUM> engaged with the latch keeper <NUM>, first panel <NUM> and second panel <NUM> may be secured in a closed position. Accordingly, in response to latch handle <NUM> being operated, the latch keeper <NUM> disengages from the latch hook <NUM>, allowing access to within first panel <NUM> and second panel <NUM>.

Latch hook length adjustment arrangement <NUM> generally comprises a frame <NUM> (also referred to herein as a latch hook frame), a latch hook body <NUM>, a nut <NUM> (also referred to herein as an adjustment nut), a sleeve <NUM> (also referred to herein as a bearing sleeve), and a spring member <NUM>. Frame <NUM> may be pivotally coupled to latch handle <NUM>. Frame <NUM> may be made from metal. Frame <NUM> may provide a load path between handle <NUM> and latch hook body <NUM>. Latch hook body <NUM> generally comprises hook <NUM> and a rod <NUM> extending from the hook <NUM>. Hook <NUM> may engage with keeper <NUM>. Rod <NUM> may be received into frame <NUM>. The relative position or extension of latch hook body <NUM> may be selectively adjusted by rotating nut <NUM> with respect to rod <NUM>.

With reference to <FIG>, frame <NUM> may comprise a wall <NUM>. Wall <NUM> may be an end wall (i.e., disposed at an end of frame <NUM>). An aperture <NUM> (also referred to herein as a first rod aperture) may be disposed in wall <NUM>. Aperture <NUM> may be configured to receive rod <NUM> of latch hook body <NUM>. An aperture <NUM> (also referred to herein as an access aperture) may be disposed in frame <NUM>. Aperture <NUM> may extend completely through frame <NUM> or may extend partially through frame <NUM> to form a cavity. Aperture <NUM> may provide clearance for installing nut <NUM>, sleeve <NUM>, and spring member <NUM> into frame <NUM>. Furthermore, aperture <NUM> may provide access for rotating nut <NUM> with respect to rod <NUM> to adjust a total length of latch hook length adjustment arrangement <NUM>.

With reference to <FIG>, a cross-section view of latch hook length adjustment arrangement <NUM> is illustrated, in accordance with various embodiments. Rod <NUM> is received by sleeve <NUM>. In various embodiments, rod <NUM> is received by nut <NUM>. In various embodiments, rod <NUM> is received by spring member <NUM>. Sleeve <NUM> may comprise a hollow cylindrical sleeve portion <NUM> and a flange <NUM> radially extending from the hollow cylindrical geometry such that flange <NUM> abuts frame <NUM> to prevent rotation of sleeve <NUM> with respect to frame <NUM>.

With combined reference to <FIG>, flange <NUM> may comprise one or more bearings <NUM> coupled thereto that extend towards nut <NUM>. In various embodiments, bearings <NUM> comprise ball bearings. Nut <NUM> may comprise a plurality of detent pockets <NUM> circumferentially disposed in a side surface <NUM> (also referred to herein as a first side surface) of nut <NUM>. Stated differently, each detent pocket <NUM> may be positioned at an equal distance away from axis <NUM>. Axis <NUM> may comprise a centerline axis of rod <NUM>. Axis <NUM> may comprise an axis of rotation of nut <NUM>. The bearing(s) <NUM> are received by detent pockets <NUM> to mechanically retain nut <NUM> at a rotational position with respect to rod <NUM> (i.e., to prevent nut <NUM> from rotating about axis <NUM> with respect to rod <NUM>). In this regard, each detent pocket <NUM> may be sized corresponding to a geometry of the bearing(s) <NUM>). To rotate nut <NUM>, a tool may be inserted into one of a plurality of adjustment pockets <NUM> disposed in a radially outer surface <NUM> of nut <NUM> to exert a torsional force on nut <NUM>. In response to the torsional force, the bias of spring member <NUM>, allowing nut <NUM> to move axially towards spring member <NUM> such that the bearing(s) <NUM> exit the associated detent pocket <NUM> as the nut <NUM> rotates about axis <NUM>. The force exerted between spring member <NUM> and nut <NUM> may be parallel to axis <NUM>. The bearing(s) <NUM> may be received by the next adjacent detent pocket <NUM> as the nut <NUM> rotates about axis <NUM> until the torsional force is no longer applied, wherein the ball bearing(s) <NUM> are received by an associated detent pocket <NUM> to prevent nut <NUM> from freely rotating. In this regard, spring member <NUM> may bias nut <NUM> towards and against sleeve <NUM>. In various embodiments, spring member <NUM> comprises a wave spring. However, any suitable style of spring may be used without departing from the scope of the present disclosure. For example, spring member <NUM> may comprise one or more coil springs, a slotted disk spring, a finger spring, a curved spring, etc. With additional reference to <FIG>, spring member <NUM> may engage a side surface <NUM> (also referred to herein as a second side surface) of nut <NUM>. Side surface <NUM> may be disposed opposite nut <NUM> from side surface <NUM>.

In various embodiments, the inner diameter surface of nut <NUM> comprises threads. Similarly, the outer diameter surface of rod <NUM> may comprise threads. In this regard, nut <NUM> may be threadingly coupled to rod <NUM>. As nut <NUM> rotates about axis <NUM>, the axial position of nut <NUM> remains substantially constant, with respect to frame <NUM>. Thus, as nut <NUM> rotates about axis <NUM>, the threaded coupling converts rotational motion of nut <NUM> into linear motion of rod <NUM>. In contrast to the inner diameter surface of nut <NUM>, the inner diameter surface of sleeve <NUM> may be generally smooth to allow rod <NUM> to freely translate therethrough. Furthermore, the inner diameter of sleeve <NUM> may be greater than the outer diameter of rod <NUM>, allowing clearance between sleeve <NUM> and rod <NUM> to prevent rod <NUM> from catching or binding on sleeve <NUM>. Thus, the inner diameter of nut <NUM> may be less than the inner diameter of sleeve <NUM>. In this manner, rod <NUM> may be configured to extend from aperture <NUM> of frame <NUM> in response to rotation of nut <NUM> in a first rotational direction with respect to rod <NUM>. Conversely, rod <NUM> may be configured to retract into aperture <NUM> of frame <NUM> in response to rotation of nut <NUM> in a second (opposite) rotational direction with respect to rod <NUM>. Stated differently, in response to rotation of nut <NUM> about axis <NUM> in the first rotational direction with respect to rod <NUM>, the rod <NUM> may be configured to move axially with respect to nut <NUM> in a first linear direction (i.e., in the negative Z-direction), and in response to rotation of nut <NUM> about axis <NUM> in the second rotational direction with respect to rod <NUM>, rod <NUM> may be configured to move axially with respect to nut <NUM> in a second linear direction (i.e., in the positive Z-direction).

With combined reference to <FIG>, to install latch hook body <NUM> to frame <NUM>, sleeve <NUM> may be inserted into aperture <NUM> (e.g., in the negative Y-direction). Hollow cylindrical sleeve portion <NUM> of sleeve <NUM> may be moved into aperture <NUM> (e.g., in the negative Z- direction), thereby aligning aperture <NUM> and sleeve <NUM>. Nut <NUM> may be moved into aperture <NUM> (e.g., in the negative Y-direction). Spring member <NUM> may be moved into aperture <NUM> (e.g., in the negative Y-direction). Nut <NUM> may be aligned with aperture <NUM>. Spring member <NUM> may be aligned with aperture <NUM>. Rod <NUM> may be inserted into aperture <NUM> and hollow cylindrical sleeve portion <NUM> (e.g., along the positive Z-direction). Rod <NUM> may be moved in the positive Z-direction and received by nut <NUM>. Rod <NUM> and/or nut <NUM> may be threadingly coupled. In this regard, rod <NUM> and/or nut <NUM> may be rotated to drive rod <NUM> in the positive Z-direction. As rod <NUM> is driven in the positive Z-direction, spring member <NUM> may receive rod <NUM>. Frame <NUM> may comprise a second wall <NUM>. An aperture <NUM> (also referred to herein as a second rod aperture) may be disposed in second wall <NUM>. Aperture <NUM> may be aligned with aperture <NUM>. Rod <NUM> may be further received by aperture <NUM>. In this installed position, rod <NUM> may retain nut <NUM>, sleeve <NUM>, and spring member <NUM> within aperture <NUM> of frame <NUM>. Furthermore, nut <NUM> may retain rod <NUM> of latch hook body <NUM> to frame <NUM>.

However, the benefits, advantages, solutions to problems, and any elements that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as critical, required, or essential features or elements of the disclosed embodiments. The scope of the claimed embodiments is accordingly to be limited by nothing other than the appended claims, in which reference to an element in the singular is not intended to mean "one and only one" unless explicitly so stated, but rather "one or more.

In the detailed description herein, references to "one embodiment", "an embodiment", "an example embodiment", etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic.

Claim 1:
A latch hook length adjustment arrangement (<NUM>) comprising:
a latch hook body (<NUM>) comprising a hook (<NUM>) and a rod (<NUM>) extending from the hook (<NUM>); and
an adjustment nut (<NUM>) comprising a first side surface (<NUM>), a second side surface (<NUM>) disposed opposite the adjustment nut (<NUM>) from the first side surface (<NUM>), and a radially outer surface (<NUM>), wherein the adjustment nut (<NUM>) is configured to threadingly couple to the rod (<NUM>),
characterized in that the latch hook length adjustment arrangement (<NUM>) further comprises:
a plurality of detent pockets (<NUM>) disposed in the first side surface (<NUM>) of the adjustment nut (<NUM>);
a bearing sleeve (<NUM>) configured to receive the rod (<NUM>), and comprising a hollow sleeve portion (<NUM>), a flange (<NUM>) extending radially outward from the hollow sleeve portion (<NUM>), and a bearing (<NUM>) disposed in the flange (<NUM>), the plurality of detent pockets (<NUM>) being configured to receive the bearing (<NUM>) to secure the adjustment nut (<NUM>) at a rotational position with respect to the rod (<NUM>); and
a spring member (<NUM>) configured to bias the adjustment nut (<NUM>) against the bearing sleeve (<NUM>).