Abstract:
Aspects of the disclosure are directed to a system configured to selectively hold open an aircraft engine cowl, comprising: a rod, a slider coupled to the rod, a track coupled to the slider, a latch coupled to the track. Aspects of the disclosure are directed to a nacelle system of an aircraft, comprising: an engine case, a bracket attached to the engine case or a cowl, a rod coupled to the bracket via a bearing, a clevis coupled to the rod, a slider coupled to the clevis, a track coupled to the slider and to the engine case or the cowl, and a latch coupled to the track that is configured to control a translation of the slider along the track based on a state of the cowl.

Description:
BACKGROUND 
       [0001]    Referring to  FIGS. 1A-1E , in connection with a nacelle  100  of an aircraft that is used to house an engine, a door opening system (DOS) and Hold Open Rod (HOR) system are used to provide a technician with access to the engine. Access is achieved by opening one of several cowls which make up the nacelle  100 . As an example, the nacelle  100  may include a fan cowl  101 , a thrust reverser  102 , an inlet cowl  103 , etc. To open, e.g., the thrust reverser  102 , a technician: (1) activates an actuator  104  of the DOS until the thrust reverser  102  is open to its maximum angle position, (2) unstows a HOR  108  from a stowed position  106 , (3) extends the HOR  108  to a deployed position, (4) attaches the HOR  108  to an engine fan case  110 , and (5) lowers thrust reverser  102  to its resting angle position, thereby resting the weight of the thrust reverser  102  on the HOR  108 . In  FIG. 1E , the portion of the nacelle  100  denoted by circle A is shown in a blown-up view once the thrust reverser  102  has been lowered to the resting position. 
         [0002]    To close the thrust reverser  102 , the technician: (1) relieves the weight of the thrust reverser  102  off the HOR  108  when the HOR  108  is in the deployed position, (2) disengages a locking mechanism of the HOR  108  to disengage the HOR  108  before being able to collapse the HOR  108 , (3) restores the HOR  108  to the stowed position  106 , and (4) closes the thrust reverser  102 . 
         [0003]    The above opening and closing procedures require the technician to carry out a number of steps in a predefined order, leading to the potential for human error if the steps are executed improperly or out-of-order. Failure to carry out the steps in an appropriate manner can potentially result in an impairment of the nacelle  100 . 
       BRIEF SUMMARY 
       [0004]    The following presents a simplified summary in order to provide a basic understanding of some aspects of the disclosure. The summary is not an extensive overview of the disclosure. It is neither intended to identify key or critical elements of the disclosure nor to delineate the scope of the disclosure. The following summary merely presents some concepts of the disclosure in a simplified form as a prelude to the description below. 
         [0005]    Aspects of the disclosure are directed to a system configured to selectively hold open an aircraft engine cowl, comprising: a rod, a slider coupled to the rod, a track coupled to the slider, a latch coupled to the track. In some embodiments, the system further comprises a locking mechanism coupled to the latch and the track. In some embodiments, the locking mechanism is configured to cause the latch to rotate in a first direction about an axis as the slider translates along the track in a first longitudinal direction when the cowl is being opened, and the locking mechanism is configured to cause the latch to rotate in a second direction about the axis that is opposite the first direction when the slider clears the latch as the slider translates along the track in the first longitudinal direction. In some embodiments, the locking mechanism comprises a solenoid. In some embodiments, the system further comprises a bracket coupled to a first end of the rod. In some embodiments, the bracket is attached to an engine case or the cowl. In some embodiments, the system further comprises a clevis coupled to a second end of the rod, and a pin coupled to the clevis and the slider. In some embodiments, a portion of the slider that contacts the track is made of polytetrafluoroethylene, and the track is made of aluminum. In some embodiments, the track includes a first section that contacts the slider. 
         [0006]    Aspects of the disclosure are directed to a nacelle system of an aircraft, comprising: an engine case, a bracket attached to the engine case or a cowl, a rod coupled to the bracket via a bearing, a clevis coupled to the rod, a slider coupled to the clevis, a track coupled to the slider and to the engine case or the cowl, and a latch coupled to the track that is configured to control a translation of the slider along the track based on a state of the cowl. In some embodiments, the nacelle further comprises a locking mechanism coupled to the latch and configured to control the latch. In some embodiments, the latch is configured to control a translation of the slider along the track based on a degree to which the cowl is open. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    The present disclosure is illustrated by way of example and not limited in the accompanying figures in which like reference numerals indicate similar elements. 
           [0008]      FIGS. 1A-1E  illustrate components and devices associated with an aircraft nacelle in accordance with the prior art. 
           [0009]      FIG. 2A  illustrates a hold open rod system in accordance with aspects of this disclosure. 
           [0010]      FIG. 2B  illustrates a pin and a slider of the system of  FIG. 2A . 
           [0011]      FIG. 2C  illustrates a track of the system of  FIG. 2A . 
           [0012]      FIG. 2D  illustrates a locking mechanism of the system of  FIG. 2A . 
           [0013]      FIGS. 3A-3D  illustrate the operation of the system of  FIG. 2A  at various stages of cowl opening or closing. 
           [0014]      FIGS. 4A-4B  illustrate a nacelle incorporating the system of  FIG. 2A . 
       
    
    
     DETAILED DESCRIPTION 
       [0015]    It is noted that various connections are set forth between elements in the following description and in the 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. A coupling between two or more entities may refer to a direct connection or an indirect connection. An indirect connection may incorporate one or more intervening entities. 
         [0016]    In accordance with various aspects of the disclosure, apparatuses, systems and methods are described for utilizing a hold open rod (HOR) in connection with an aircraft engine nacelle cowl. The HOR may be coupled (e.g., permanently mounted) to a first structure (e.g., a fan case or cowl) at a first end. At a second end of the HOR, the HOR may be associated with a clevis that couples to a slider. The slider may couple to a track. Nearing a fully opened position, the slider may push past a spring loaded mechanism, which then restricts motion back down the track thereby holding open a cowl. To close the cowl, the cowl may be lifted slightly to relieve the load off the locking mechanism. A solenoid or other device may then be activated that would pull back on the mechanism, allowing the slider to move down the track. 
         [0017]    Referring now to  FIG. 2A , a system  200  is shown. The system  200  may be implemented as a part of a nacelle of an aircraft. The system  200  includes a number of components and devices that are described in greater detail below. 
         [0018]    The system  200  may include a bracket  202 . The bracket  202  may couple to a structure of the nacelle, such as a fan case (e.g., fan case  110  of  FIG. 1 ). The bracket  202  may be made of one or more materials, such as aluminum. The coupling may be facilitated using mounting or attachment hardware (e.g., nuts, bolts, washers, etc.) as would be appreciated by one of skill in the art. 
         [0019]    The system  200  may include a bearing or bushings  204 , a HOR  206 , and a clevis  208 . The bearing  204 , which may include a spherical bearing, may enable the HOR  206  to rotate/pivot about the bracket  202  as the cowl is being opened or closed. The HOR  206  may be made of one or more materials, such as steel. While described as separate components/devices, two or more of the bearing  204 , the HOR  206 , and the clevis  208  may be formed as a common component/device. 
         [0020]    The clevis  208  and an associated pin  210  may be used for coupling (e.g., attaching) the HOR  206  and a slider  212 . Referring to  FIG. 2B , a closer view of the pin  210  and the slider  212  is shown. The slider  212  may be made of one or more materials, such as steel. An interior portion  214  of the slider  212  may be made of a low-friction material, such as polytetrafluoroethylene (e.g., Teflon™). Referring to  FIGS. 2A-2B , the interior portion  214  of the slider  212  may couple to or contact a track  222 . The track  222  may be made of one or more materials, such as aluminum. 
         [0021]    Referring to  FIG. 2C , a closer view of the track  222  is shown. The track  222  and the slider  212  may be D-shaped, similar to a dovetail joint, or other common sliding joint shapes such as a ball joint. The track  222  may include a first section  222 - 1  that contacts the slider  212  (e.g., the interior portion  214 ). The first section  222 - 1  may be made of or treated with a low friction material. A second section  222 - 2  of the track  222  that is not subject to contact with the slider  212  may be made of the same or another material and surface treatment. The two sections  222 - 1  and  222 - 2  may compose a single component or be two separate components joined together. 
         [0022]    Referring to  FIGS. 2A and 2D , the system  200  may include a locking mechanism  232 . The locking mechanism  232  may include a latch  234  coupled to a solenoid  236  (e.g., a spring loaded pulling solenoid) or other spring device. The solenoid  236  may be coupled (e.g., fixedly mounted) to the track  222 , for example the second section  222 - 2 . In some embodiments, the slider  212  may be locked by a spring loaded latch that is manually unlocked via a cable pull by a technician upon cowl closing. The slider  212  may be unlocked by an electronic servo motor turning a torsion spring. Also, it is possible the lock device is not spring loaded, rather designed such that it defaults to the locked position via inertial forces. 
         [0023]    The latch  234  may be coupled (e.g., attached) to the track  222  at a location  244 . The coupling at the location  244  may be facilitated using mounting or attachment hardware (e.g., nuts, bolts, washers, bushings, etc.) as would be appreciated by one of skill in the art. The location  244  may serve as an axis of rotation for the latch  234  with respect to the track  222 . 
         [0024]    Referring to  FIG. 2A , the system  200  may include one or more brackets  252 . The brackets  252  may be used to couple (e.g., mount or attach) the track  222  to a structure (e.g., the engine fan case  110  or a thrust reverser  102  of  FIG. 1 ). The size or dimensions of the brackets  252 , as well as the materials that are used for the brackets  252 , may be selected based on structural loads that the brackets  252  may need to accommodate. 
         [0025]    Referring to  FIGS. 3A-3D , the operation of the system  200  is shown at various points/stages during an opening of a cowl of a nacelle  300  (where zoomed-in portions of the nacelle  300  are denoted via the letter ‘A’ as shown in each of the respective FIGS.). In  FIG. 3A , the cowl is (substantially) closed. During the opening of the cowl, the HOR  206  rotates about the bracket  202  in a first direction (counterclockwise in  FIG. 3B ), and the slider  212  is translated in a first longitudinal direction (up-and-to-the-left in  FIG. 3B ) along the track  222 . Once the cowl has been opened by a first amount (e.g., approximately equal to the cowl&#39;s resting open position), the slider  212  contacts the latch  234 , and the latch  234  rotates about the axis  244  in a first direction (clockwise in  FIG. 3B ). 
         [0026]    A technician will typically cause the cowl to open beyond this first amount, such that the cowl is open by a second amount (e.g., a couple of degrees beyond its resting open position).  FIG. 3C  illustrates such a scenario. As shown in  FIG. 3C , the HOR  206  has been further rotated about the bracket  202  in the first direction and the slider  212  has been further translated in the first longitudinal direction along the track  222  relative to  FIG. 3B , such that the slider  212  clears or no longer contacts the latch  234 . Once the slider  212  clears the latch  234 , the latch  234  may rotate about the axis  244  in a second direction (counterclockwise in  FIG. 3C ) that is opposite the first direction of rotation described above in connection with  FIG. 3B . Such rotation may be brought about as a result of a force within the solenoid  236 . For example, a spring associated with the mechanism  232  may cause the latch  234  to rotate in the second direction. Spring force or inertial forces may force the latch  234  to lock back onto the track  222  automatically. Magnetism may be employed for such a purpose. 
         [0027]    Once the cowl is open by this second amount, the cowl may be lowered to a resting open position in order to allow the technician to perform, e.g., a maintenance or inspection activity.  FIG. 3D  illustrates such a scenario, where the cowl is in the rest position. Relative to  FIG. 3C , in  FIG. 3D  the HOR  206  has been rotated about the bracket  202  in a second direction (e.g., clockwise) and the slider  212  has been translated in a second longitudinal direction (e.g., down-and-to-the right) along the track  222 . The movement of the HOR  206  and the slider  212  in transitioning from  FIG. 3C  to  FIG. 3D  may stop when the slider  212  abuts/contacts the latch  234 . 
         [0028]    In order to close the cowl following the maintenance or inspection activity, the steps described above in connection with  FIGS. 3A-3D  may be performed in reverse. For example, the load from the thrust reverser cowl imposed on the latch  234  may be removed by further opening the cowl (e.g., transitioning the cowl from being at a resting open position to a fully open position). Next, the solenoid  236  may be engaged, forcing the latch  234  to rotate in, e.g., the clockwise direction in  FIGS. 3A-3D . This rotation of the latch  234  may create a path to enable the slider  212  to translate about the track  222  in the second longitudinal direction (e.g., down-and-to-the-right) until the cowl is (substantially) fully closed. 
         [0029]      FIGS. 4A-4B  illustrate a nacelle  400  (which may correspond to the nacelle  300  of  FIGS. 3A-3D ) that incorporates the system  200  of  FIG. 2A . The thrust reverser  102  is shown in its resting open position held open by the system  200 . 
         [0030]    Technical effects and benefits of this disclosure include the provisioning of a locking mechanism that is self-deploying when a cowl is substantially in a fully opened position. Such a device may use at numerous steps along the track  222  to allow different locked open positions of the cowl. This would eliminate the possibility of a technician inadvertently forgetting to lock open the cowl during, e.g., a maintenance or inspection activity. A solenoid may be remotely operated (e.g. electronically or mechanically), thereby allowing the technician to be a clear distance from cowl which is opening or closing. 
         [0031]    Aspects of the disclosure have been described in terms of illustrative embodiments thereof. Numerous other embodiments, modifications, and variations within the scope and spirit of the appended claims will occur to persons of ordinary skill in the art from a review of this disclosure. For example, one of ordinary skill in the art will appreciate that the steps described in conjunction with the illustrative figures may be performed in other than the recited order, and that one or more steps illustrated may be optional in accordance with aspects of the disclosure. One or more features described in connection with a first embodiment may be combined with one or more features of one or more additional embodiments.