Patent Application
20240043128
This application claims priority to Indian Patent Appln. No. 202211044443 filed on Aug. 3, 2022, which is hereby incorporated herein by reference in its entirety.
The present disclosure relates generally to latch handle assemblies capable of being used in an aircraft and, more particularly, to adjustable latch hooks for latch handle assemblies.
Latch assemblies are commonly used in the nacelle of an aircraft, for example, in fan cowls that enclose the engine fan case. Fan cowls are hinged to the pylon or to a frame structure attached at the top of the nacelle. Aircraft fan cowls are often held together with latch assemblies at various axial positions along the fan case. Fan cases may be encased by a fan cowl having two members, which fan cowl members 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 each fan cowl member to be pivoted between an open configuration and a closed configuration. The open configuration provides access into the nacelle (e.g., to the engine). In closed configuration, the fan cowl members are positioned to close access to the nacelle and provide an aerodynamic exterior surface. Due to build tolerance of the nacelle components, a fan cowl latch assembly is typically adjustable to fit each individual nacelle and to adjust for geometrical changes of the nacelle over time. Nacelle and fan cowl designs are often influenced by the size of the components that must be enclosed within the nacelle and fan cowl. A larger nacelle/fan cowl (e.g., one large enough to house conventional components) may provide disadvantages including aerodynamic drag, additional weight, and the like. Hence, in some instances there is a desire to utilize smaller and/or thinner configurations in the fan cowl region of the nacelle.
What is needed is a latch assembly that can be used in a variety of different nacelle configurations, including those that must be used in limited spaces.
According to an aspect of the present disclosure, a latch mechanism is provided that includes a latch housing, a latch keeper, and a latch hook adjustment assembly. The latch keeper may have a retaining member. The latch hook adjustment assembly includes a latch frame, a latch handle, a hook member, a bearing block, a nut, and a spring member. The latch frame has a front wall having a front wall aperture, an interior wall, and a forward cavity disposed between the front wall and the interior wall. The latch handle extends lengthwise between a first end and a second end, and the latch handle is pivotally attached to the latch housing. The hook member has a shaft extending out from a hook, and at least a portion of the shaft is threaded. The bearing block has a flange, one or more indexing features, and a bearing block bore. The flange has a first side surface and a second side surface. The first side surface is opposite the second side surface. The indexing features project outwardly from the second side surface, and the bore extends through the flange. The indexing features are disposed adjacent the bearing block bore. The nut has a first axial end surface, a second axial end surface, and a nut bore that extends through the first and second axial end surfaces. At least a portion of the nut bore is configured for threaded engagement with the hook member shaft. The index cavities are disposed in the first axial end surface adjacent the nut bore. The bearing block, nut, and spring member are disposed in the forward cavity of the latch frame, and the shaft of the hook member extends through the front wall aperture, the bearing block, the nut, and the spring member. The shaft is in threaded engagement with the nut. The latch hook adjustment assembly is disposable in an engaged configuration wherein the one or more indexing features are engaged with the plurality of index cavities, and a disengaged configuration wherein the one or more indexing features are disengaged with the plurality of index cavities.
In any of the aspects or embodiments described above and herein, the index cavities may be disposed in communication with nut bore, and the one or more indexing features may be disposed for radial alignment with the plurality of index cavities.
In any of the aspects or embodiments described above and herein, the index cavities may be configured to mate with the one or more indexing features.
In any of the aspects or embodiments described above and herein, the mating configuration between the index cavities and the indexing features may permit the latch hook adjustment assembly to be moved from an engaged configuration to a disengaged configuration by rotation of the nut.
In any of the aspects or embodiments described above and herein, the bearing block may include a pilot boss extending outwardly from the second side surface contiguous with the bearing block bore, and the nut may include a pilot boss bore disposed in the first axial end surface contiguous with the nut bore, wherein the pilot boss bore is configured to receive the pilot boss.
In any of the aspects or embodiments described above and herein, the index cavities may be contiguous with the pilot boss bore and are open to the pilot boss bore.
In any of the aspects or embodiments described above and herein, the plurality of indexing features may be contiguous with the pilot boss.
In any of the aspects or embodiments described above and herein, the bearing block may include a sleeve extending outwardly from the first side surface and the bearing block bore may extend through the sleeve, and the sleeve may be configured to be receivable within the front wall aperture.
In any of the aspects or embodiments described above and herein, the latch frame may include a top wall and a bottom wall, wherein the front wall extends between the top wall and the bottom wall, and the interior wall extends between the top wall and the bottom wall, and the forward cavity is defined by the front wall, top wall, the bottom wall, and the interior wall, and the interior wall includes an interior wall aperture aligned with the front wall aperture.
In any of the aspects or embodiments described above and herein, the nut may include an outer radial surface and a plurality of engagement recesses disposed in the outer radial surface.
According to an aspect of the present disclosure, a latch hook adjustment assembly is provided that includes a latch frame, a pivotally mounted latch handle, a hook member, a bearing block, and a nut. The latch frame has a front wall having a front wall aperture, an interior wall, and a forward cavity disposed between the front wall and the interior wall. The pivotally mounted latch handle extends lengthwise between a first end and a second end and is in communication with latch frame. The hook member has an at least partially threaded shaft. The bearing block has a first side surface and a second side surface, the first side surface being opposite the second side surface. The bearing block further includes a bearing block bore and indexing features that project outwardly from the second side surface. The bearing block bore extends between the first and second side surfaces. The indexing features are disposed adjacent the bearing block bore. The nut has first and second axial end surfaces and a nut bore that extends through the first and second axial end surfaces. At least a portion of the nut bore is configured for threaded engagement with the hook member shaft. The index cavities are disposed in the first axial end surface adjacent the nut bore. The bearing block and nut are disposed in the forward cavity of the latch frame, and the shaft of the hook member extends through the front wall aperture, the bearing block, and the nut, and the shaft is in threaded engagement with the nut. The latch hook adjustment assembly is disposable in an engaged configuration wherein the indexing features are engaged with the index cavities, and a disengaged configuration wherein the indexing features are disengaged with the plurality of index cavities.
According to an aspect of the present disclosure, an aircraft nacelle is provided that includes a fan cowl, a latch keeper, and at least one latch hook adjustment assembly. The fan cowl has first and second fan cowl members. The latch keeper is attached to the second fan cowl member. The latch hook adjustment assembly is attached to the first cowl member. The latch hook assembly includes a latch frame, a pivotally mounted latch handle, a hook member, and a bearing block. The latch frame has a front wall having a front wall aperture, an interior wall, and a forward cavity is disposed between the front wall and the interior wall. The pivotally mounted latch handle extends lengthwise between first and second ends, and the second end is in communication with the latch frame. The hook member has an at least partially threaded shaft. The bearing block has a first side surface, a second side surface, one or more indexing features, and a bearing block bore. The first side surface is opposite the second side surface. The indexing features project outwardly from the second side surface. The bearing block bore extends between the first and second side surfaces, and the indexing features are disposed adjacent the bearing block bore. The nut has first and second axial end surfaces and a nut bore that extends through the first and second axial end surfaces. At least a portion of the nut bore is configured for threaded engagement with the hook member shaft. The index cavities are disposed in the first axial end surface adjacent the nut bore. The bearing block and nut are disposed in the forward cavity of the latch frame, and the shaft of the hook member extends through the front wall aperture, the bearing block, and the nut. The shaft is in threaded engagement with the nut. The latch hook adjustment assembly is disposable in an engaged configuration wherein the one or more indexing features are engaged with the plurality of index cavities, and a disengaged configuration wherein the one or more indexing features are disengaged with the plurality of index cavities.
The foregoing features and elements may be combined in various combinations without exclusivity, unless expressly indicated otherwise. For example, aspects and/or embodiments of the present disclosure may include any one or more of the individual features or elements disclosed above and/or below alone or in any combination thereof. These features and elements as well as the operation thereof will become more apparent in light of the following description and the accompanying drawings. It should be understood, however, the following description and drawings are intended to be exemplary in nature and non-limiting.
Aspects of the present disclosure include latch mechanisms that may be used in an aircraft fan cowl, an aircraft fan cowl that utilizes the present disclosure system, and an aircraft that utilizes the present disclosure system.
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In some embodiments, the latch handle 46 may include a lock mechanism (not shown) for maintaining the latch handle 46 in the closed position. The lock mechanism may be accessed through an aperture 80 disposed in the latch handle 46. To release the lock mechanism, a tool may be inserted into the aperture 80 to actuate the lock mechanism and thereby release the latch handle 46. Rotating the latch handle 46 into the closed position automatically actuates the lock mechanism to maintain the latch handle 46 in the closed position.
The hook member 48 includes a hook 82 and a shaft 84 attached to the hook 82. The shaft 84 extends outwardly from the hook 82. The hook 82 is configured for releasable engagement with the retaining member 42 of the latch keeper 40. The hook 82 has an interior region 86 with an opening 88. The interior region 86 is configured to receive and mate with the retaining member 42. The opening 88 is configured to permit the retaining member 42 to ingress and egress the hook interior region 86. The shaft 84 extends lengthwise between a first lengthwise end and a second lengthwise end. The hook 82 is attached to the first lengthwise end of the shaft 84. The shaft 84 includes an exterior surface 83. At least a portion of the shaft exterior surface 83 is threaded.
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The nut 52 (see
The spring member 54 (e.g., see
To facilitate a complete understanding of the present disclosure, the elements of the latch hook adjustment assembly 38 will now be described in assembled form. To begin, the bearing block 50 may be inserted into the latch frame 44. More specifically, the bearing block 50 may be inserted into the forward cavity 70 of the latch frame 44, with the cylindrical sleeve 90 being inserted into the front wall aperture 72. In the assembled form, the flange first surface 100 is disposed adjacent the inside surface of the front wall 56. Subsequently, the nut 52 may be inserted into the forward cavity 70 with the first axial surface 104 of the nut 52 facing the flange second surface 102 and the spring member 54 inserted between the nut 52 and the interior wall 66 of the latch frame 44. The front wall aperture 72, the bearing block bore 98, the nut bore 110, the center aperture 118 of the spring member 54, and the interior wall aperture 74 are aligned along a common axis.
The shaft 84 of the hook member 48 is inserted into the cylindrical sleeve 90 of the bearing block 50 (e.g., non-interference fit) until it engages with the nut 52. Upon engagement with the nut 52, the threaded portion of the hook member shaft 84 is threadedly engaged with the nut 52. As the hook member shaft 84 is threaded through the nut 52, the hook member shaft 84 extends through the center aperture 118 of the spring member 54 (e.g., non-interference fit) and the interior wall aperture 74 (e.g., non-interference fit). As will be detailed below, the axial travel of the hook member 48 relative to the latch frame 44 and the nut 52 provides adjustment for the latch mechanism 34.
As an example of operation of the present disclosure latch mechanism 34, the first and second fan cowl members 28A, 28B of a nacelle 24 may be rotated to a position that is near the closed position. The latch mechanism 34 may be actuated to permit the hook 82 of the hook member 48 to engage with the retaining member 42 of the latch keeper 40. Once the hook 82 is engaged with the retaining member 42, to complete the closing process the latch handle 46 is rotated (e.g., the second lengthwise end 78 of the latch handle 46 is rotated toward the second latch housing unit 36B and the second fan cowl member 28B) until the reaching the closed position where it may be retained by the lock mechanism if used. In this position, the flange indexing features 96 are received within the nut index cavities 114 and the nut 52 is inhibited from rotation as a result of that engagement. In addition, the latch mechanism 34 may be configured so that the spring member 54 applies some amount of biasing force against the nut 52 to facilitate maintaining engagement between the flange indexing features 96 and the nut index cavities 114.
In the event the user seeks to adjust the latch mechanism 34 (e.g., to change the axial position of the hook member 48 and therefore the closing of the first and second fan cowl members 28A, 28B), the user may rotate the nut 52 (which may require a tool). Rotation of the nut 52 will cause the flange indexing features 96 to disengage with the previously engaged nut index cavities 114 (i.e., move from a flange indexing feature 96/nut index cavity 114 engagement position to a flange indexing feature 96/nut index cavity 114 disengagement position). The movement from engagement to disengagement will cause axial movement of the nut 52 away from the bearing block flange 92 and will change the axial position of the hook member 48 (amount depending on amount of nut 52 rotation). The axial movement of the nut 52 relative to the bearing block flange 92 will cause compression of the spring member 54. Since the hook member shaft 84 is threadedly engaged with the nut 52 and the nut 52 is captured in the forward cavity 70 of the frame, the amount of axial hook member 48 adjustment desired will dictate how much rotation of the nut 52 is required. When the axial position of the hook member 48 has been adjusted to the desired degree, the nut 52 may be rotated to the nearest rotational position where flange indexing features 96 will once again be engaged with nut index cavities 114. As the nut 52 is rotated into the engaged position, the nut 52 will move axially toward the bearing block flange 92 and the compression of the spring member 54 will decrease.
A person of skill in the art will recognize that the environment in which latch mechanisms are disposed is a dirty environment where oils, direct, and other debris can accumulate on surfaces. As described above, the present disclosure latch mechanism utilizes a nut 52 having a detent or non-rotation capability provided by engagement features (i.e., nut index cavities 114) contiguous with an inner diameter of the nut 52. This configuration is understood to decrease the probability of such features (i.e., the nut index cavities 114) becoming clogged with debris, particularly relative to other latch mechanisms that utilize a nut 52 have detent cavities wholly disposed in an axially end face or disposed at the outer radial edge of a nut 52 which often has greater exposure to environmental elements.
The bearing block 50 and adjustment nut 52 combination of the present disclosure serve multiple functions that facilitate the operation of the present disclosure latch mechanism 34. For example, the cylindrical sleeve 90 portion of the bearing block 50 facilitates positioning of the bearing block 50 within the forward cavity 70 of the latch frame 44. The pilot boss 94 of the bearing block 50 facilitates positioning of the nut 52 relative to the bearing block 50. The cylindrical sleeve 90 portion of the bearing block 50 also facilitates engagement between the threaded portion of the hook member shaft 84 and the threaded portion of the nut bore 110; e.g., during assembly. The bearing block 50 and the nut 52 cooperate to prevent rotation of the nut (e.g., via the indexing features 96 and the index cavities 114) during use, but still allow rotation of the nut 52 for adjustment purposes. The bearing block flange 92 functions to distributes load applied to the nut 52 to the latch frame 44 (e.g., to the top wall 58 and the bottom wall 60).
Another significant aspect of the present disclosure relates to the indexing function provided by the indexing features 96 and the index cavities 114. The indexing features 96 and the index cavities 114 obviate the need for features (e.g., ball bearings disposed in a surface, and pockets disposed in an end face of a nut, separated from the bore of the nut). The present indexing features 96 and the index cavities 114 provide the desired indexing function (thereby preventing rotation of the nut during latch mechanism use) but also allow rotation of the nut 52 for adjustment purposes. Importantly, the indexing features 96 and the index cavities 114 are configured such that the index cavities 114 are contiguous with the pilot boss bore 112 and the indexing features 96 are positioned to engage with the index cavities 114 at this inwardly radial location. As stated above, this configuration facilitates avoiding debris clogging. Perhaps more importantly, the inwardly radial positioning of the indexing features 96 and the index cavities 114 permits the nut 52 to have a smaller outer diameter while still permitting full positional adjustment of the hook member 48 and still providing the anti-rotation capability. The smaller outer diameter of the nut 52, in turn, permits a smaller height latch frame 44 (i.e., the distance from the outer surface of the top wall 58 to the outer surface of the bottom wall 60). This results in a decreased overall height latch mechanism (e.g., along the X-axis), which is beneficial for nacelle applications with space limitations that require a smaller envelope latch mechanism 34.
While the principles of the disclosure have been described above in connection with specific apparatuses and methods, it is to be clearly understood that this description is made only by way of example and not as limitation on the scope of the disclosure. Specific details are given in the above description to provide a thorough understanding of the embodiments. However, it is understood that the embodiments may be practiced without these specific details.
It is noted that the embodiments may be described as a process which is depicted as a flowchart, a flow diagram, a block diagram, etc. Although any one of these structures may describe the operations as a sequential process, many of the operations can be performed in parallel or concurrently. In addition, the order of the operations may be rearranged. A process may correspond to a method, a function, a procedure, a subroutine, a subprogram, etc.
The singular forms “a,” “an,” and “the” refer to one or more than one, unless the context clearly dictates otherwise. For example, the term “comprising a specimen” includes single or plural specimens and is considered equivalent to the phrase “comprising at least one specimen.” The term “or” refers to a single element of stated alternative elements or a combination of two or more elements unless the context clearly indicates otherwise. As used herein, “comprises” means “includes.” Thus, “comprising A or B,” means “including A or B, or A and B,” without excluding additional elements.
It is noted that various connections are set forth between elements in the present description and drawings (the contents of which are included in this disclosure by way of reference). It is noted that these connections are general and, unless specified otherwise, may be direct or indirect and that this specification is not intended to be limiting in this respect. Any reference to attached, fixed, connected or the like may include permanent, removable, temporary, partial, full and/or any other possible attachment option.
No element, component, or method step in the present disclosure is intended to be dedicated to the public regardless of whether the element, component, or method step is explicitly recited in the claims. No claim element herein is to be construed under the provisions of 35 U.S.C. 112(f) unless the element is expressly recited using the phrase “means for.” As used herein, the terms “comprise”, “comprising”, or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.
While various inventive aspects, concepts and features of the disclosures may be described and illustrated herein as embodied in combination in the exemplary embodiments, these various aspects, concepts, and features may be used in many alternative embodiments, either individually or in various combinations and sub-combinations thereof. Unless expressly excluded herein all such combinations and sub-combinations are intended to be within the scope of the present application. Still further, while various alternative embodiments as to the various aspects, concepts, and features of the disclosures—such as alternative materials, structures, configurations, methods, devices, and components, and so on—may be described herein, such descriptions are not intended to be a complete or exhaustive list of available alternative embodiments, whether presently known or later developed. Those skilled in the art may readily adopt one or more of the inventive aspects, concepts, or features into additional embodiments and uses within the scope of the present application even if such embodiments are not expressly disclosed herein. For example, in the exemplary embodiments described above within the Detailed Description portion of the present specification, elements may be described as individual units and shown as independent of one another to facilitate the description. In alternative embodiments, such elements may be configured as combined elements.
| Number | Date | Country | Kind |
|---|---|---|---|
| 202211044443 | Aug 2022 | IN | national |
