Abstract:
Aspects of the disclosure are directed to a system for a thrust reverser of an aircraft comprising: a primary sleeve, and a secondary sleeve, wherein a first stroke associated with the primary sleeve is different from a second stroke associated with the secondary sleeve, and wherein the primary sleeve traverses a first distance associated with the first stroke at the outset of a deployment of the thrust reverser and a second distance associated with the first stroke at a later stage of the deployment.

Description:
BACKGROUND 
       [0001]    Within a turbo fan engine that utilizes a cascade type thrust reverser, there are typically a plurality of blocker doors that deploy in order to redirect engine bypass air thru a set of cascades that redirect the airflow out and forward in order to reverse the direction of the thrust of the engine. This may be done to slow an aircraft after landing. Referring to  FIG. 1A , a system  100  is shown. The system  100  includes a sleeve  102  that is translated or moved in, e.g., an aft direction in order to expose cascades  104  as part of the deployment of the thrust reverser. Similarly, in order to place the thrust reverser in a stowed state (e.g., during flight) the sleeve  102  is translated or moved in, e.g., a forward (FWD) direction, such that the sleeve  102  may contact or abut a nacelle structure  106 . When in the stowed state, the cascades  104  are not exposed.  FIG. 4  illustrates the system  100  in the stowed state. An entirety of a nacelle is shown in  FIG. 4 , whereas a portion (e.g., a half) of the nacelle is shown in  FIG. 1A . 
         [0002]      FIG. 1B  illustrates a blocker door  108  of the system  100  hinged to the sleeve  102  near a point  110 . Additionally, the door  108  is attached to the inner fixed structure  114  of the thrust reverser via a drag link  112  that retains the door  108  in position during normal flight as well as aids in the deployment of the door  108  during thrust reverse mode. During flight, the door  108  forms, in part, the outer surface of a bypass duct. The drag link  112  crosses this bypass duct in attaching to the inner fixed structure. 
         [0003]    New configurations for a thrust reverser have been proposed which represent improvements over the basic, common configuration illustrated in  FIGS. 1A and 1B . Some of these new configurations feature a first and second movable structure that must each be moved during thrust reverser deployment at different rates of movement. For example, in co-pending patent application Ser. No. 14/534,988 filed Nov. 6, 2014, a thrust reverser is proposed with a primary and secondary sleeve each of which slides in a fore and aft direction, and each of which requires a different range of motion or stroke, and different actuation rates. It would be possible to include two separate thrust reverser actuation systems which each independently actuate the primary and the secondary sleeve. However, such an arrangement might be heavier and costlier and less optimal in other respects, too. This disclosure proposes a way to link the deployment of two (or possibly more) components, such as a primary and secondary sleeve, so that their deployment can be linked and coordinated and may be accomplished with a single thrust reverser actuation system. Of course, in addition to the specific embodiments disclosed in patent application Ser. No. 14/534,988, there are other embodiments of thrust reversers which would also benefit from this capability. 
       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 for a thrust reverser of an aircraft comprising: a primary sleeve, and a secondary sleeve, wherein a first stroke associated with the primary sleeve is different from a second stroke associated with the secondary sleeve, and wherein the primary sleeve traverses a first distance associated with the first stroke at the outset of a deployment of the thrust reverser and a second distance associated with the first stroke at a later stage of the deployment. In some embodiments, the first distance is greater than the second distance. In some embodiments, the system further comprises at least one actuator configured to drive at least one of the primary sleeve and the secondary sleeve. In some embodiments, the primary sleeve is coupled to the secondary sleeve, and the at least one actuator is configured to drive the secondary sleeve in order to cause an actuation of the primary sleeve. In some embodiments, the primary sleeve is coupled to the secondary sleeve via a plurality of four-bar mechanisms arranged in series. In some embodiments, the plurality of four-bar mechanisms comprises: a first four-bar mechanism comprising: the secondary sleeve, a second link coupled to the secondary sleeve, a first link coupled to the second link, and a first fixed structure coupled to the first link, a second four-bar mechanism comprising: the first link, a third link coupled to the first link, a second fixed structure coupled to the third link, and the primary sleeve coupled to the second fixed structure. In some embodiments, the first fixed structure comprises at least one of a clevis and a beam. In some embodiments, the second fixed structure comprises at least one of a clevis and a bond panel. In some embodiments, the at least one actuator comprises a first actuator configured to drive the primary sleeve and a second actuator that is configured to drive the secondary sleeve. 
         [0006]    Aspects of the disclosure are directed to a kinematic mechanism for actuating a thrust reverser, comprising: a clevis coupled to fixed structure, and at least one link pivotally coupled to the clevis, wherein the at least one link couples a primary sleeve and a secondary sleeve. In some embodiments, the at least one link comprises a plurality of links. In some embodiments, the kinematic mechanism is configured to cause the primary sleeve to traverse a first distance at the outset of a deployment of the thrust reverser and a second distance at a later stage of the deployment. In some embodiments, the kinematic mechanism further comprises at least one actuator configured to drive at least one of the primary sleeve and the secondary sleeve. In some embodiments, the at least one actuator is configured to drive the secondary sleeve in order to cause an actuation of the primary sleeve. 
     
    
     
       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]      FIG. 1A  illustrates a thrust reverser system incorporating a translating sleeve. 
           [0009]      FIG. 1B  illustrates a drag link of the system of  FIG. 1A . 
           [0010]      FIGS. 2A-2C  illustrate a thrust reverser system incorporating aspects associated with a master-slave actuation/configuration for a plurality of sleeves. 
           [0011]      FIGS. 3A-3C  illustrate a thrust reverser system incorporating aspects associated with separate/independent actuation for a plurality of sleeves. 
           [0012]      FIG. 4  illustrates a nacelle incorporating a thrust reverser. 
       
    
    
     DETAILED DESCRIPTION 
       [0013]    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. 
         [0014]    In accordance with various aspects of the disclosure, apparatuses, systems and methods are described for making and using a translating cascade thrust reverser. In some embodiments, a translating/primary sleeve may operate separate/independent from a translating cascade, potentially without the use of separate actuation or a duplicate thrust reverser actuation system (TRAS). By doing so, the sleeve and the cascade can be operated at different speeds and different distances. As used herein, a stroke refers to the distance that a respective element may traverse. 
         [0015]    Referring to  FIGS. 2A-2C , a system  200  is shown. The system  200  includes a number of components/devices that are described further below. The system  200  may be indicative of a portion of an overall thrust reverser system. For example, the system  200  may correspond to an upper portion of an overall thrust reverser system, such that a lower portion of the overall thrust reverser system may include analogous components/devices. 
         [0016]    The system  200  includes a first link  222 , a second link  224 , and a third link  226 . The first link  222  may be coupled to the second link  224 . The first link  222  may be coupled to the third link  226 . 
         [0017]    The first link  222  may be coupled to a first clevis  228 . For example, the first link  222  may be pivotally connected to the first clevis  228 . The first clevis  228  may be coupled to a beam  230  which is thrust reverser fixed structure. 
         [0018]    The second link  224  may be coupled to one or more translating cascades  232 . A translating cascade  232  may also be referred to as a secondary sleeve. The translating cascades  232  may be configured to translate on a track and slider. The translating cascades  232  may be driven by a TRAS, which is not explicitly shown but is represented by reference character  234 . The TRAS may constitute a hydraulic or pneumatic actuation cylinder, or a mechanical lead screw driven by a hydraulic, pneumatic or electric motor, or other options as will be recognized by those of ordinary skill in this art. 
         [0019]    The third link  226  may be coupled to a second clevis  236 . The second clevis  236  may be coupled to a bond panel  238  which forms part of the sleeve  202 . 
         [0020]    As shown, a sleeve  202  (which may be similar to the sleeve  102  of the system  100 ) and a structure  206  (which may correspond to the structure  106  of the system  100 ) are included as part of the system  200 . The sleeve  202  may be referred to herein as a primary sleeve. The sleeve  202  may be configured to translate on a track and slider separate from the track and slide for the secondary sleeve including the cascade  232 . 
         [0021]    The system  200  may include a plurality of four-bar mechanisms. A first four-bar mechanism may include the translating cascades  232 , the second link  224 , the first link  222 , and a first fixed structure (illustratively represented by one or more of the structure  206 , the beam  230 , and the first clevis  228 ). A second four-bar mechanism may include the first link  222 , the third link  226 , the sleeve  202 , and the fixed structure (illustratively represented by one or more of the second clevis  236  and the bond panel  238 ). The four-bar mechanisms may be arranged in series with one another. 
         [0022]    In the progression from  FIG. 2A  to  FIG. 2B  and from  FIG. 2B  to  FIG. 2C , the translating cascades  232  transition from a stowed state ( FIG. 2A ), to a partially deployed state ( FIG. 2B ), to a deployed state ( FIG. 2C ), coinciding with a transition of the thrust reverser from a stowed state to a deployed state. 
         [0023]    As shown in the progression associated with  FIGS. 2A-2C , actuation of the translating cascades  232  may cause an actuation or movement of the sleeve  202 . Accordingly, the system  200  may adhere to a master-slave type of configuration, where the translating cascades  232  play the role of a master mechanism and the sleeve  202  plays the role of a slave mechanism. In other embodiments, the roles may be reversed such that the sleeve  202  plays the role of the master mechanism and is directly actuated by a TRAS, and the translating cascades  232  play the role of the slave mechanism. 
         [0024]    Superimposed in  FIG. 2C  is an illustration of a stroke  202 ′ associated with the sleeve  202  relative to a stroke  232 ′ associated with the translating cascades  232 . As shown in  FIG. 2C , the stroke  202 ′ is different from the stroke  232 ′. 
         [0025]    In terms of the movement of the sleeve  202  in  FIGS. 2A-2C , the sleeve  202  may move a greater distance in transitioning from a stowed state ( FIG. 2A ) to a partially deployed state ( FIG. 2B ) than in transitioning from the partially deployed state to a fully deployed state ( FIG. 2C ). In other words, the ratio of the deployment rate of the sleeve  202  to the deployment rate of the cascade  232  or secondary sleeve may vary depending upon the deployment position of the thrust reverser as a result of the kinematic arrangement/mechanism of the system  200 . Such features may be desirable, given that the translating cascades  232  will tend to experience the greatest loading when the thrust reverser is fully deployed. Also, such a movement of the sleeve  202  a greater distance at the outset of the thrust reverser deployment may facilitate the provisioning of room to support the deployment of a blocker door (not shown). 
         [0026]    As described above, the system  200  may adhere to a master-slave configuration, wherein actuation of a first sleeve (e.g., translating cascades  232 ) may cause a movement or displacement of a second sleeve (e.g., sleeve  202 ). In other embodiments, an additional actuation input may be used in order to control the actuation of the translating cascades  232  and the sleeve  202 . For example, referring to  FIGS. 3A-3C , a system  300  that incorporates aspects of an additional input is shown. The system  300  includes an actuator  334  associated with the fixed structure  206  that is separate from the TRAS  234  associated with the translating cascades  232 . The actuator  334  is coupled to a translating clevis  328  on the beam  230 . 
         [0027]    As shown in the progression from  FIG. 3A  to  FIG. 3B  and in the progression from  FIG. 3B  to  FIG. 3C , the sleeve  202  is displaced/translated a given distance via the retraction of the actuator  334 , while the translating cascades  232  have not been displaced. An internal lock in the TRAS  234  may keep the translating cascades  232  from moving. This sleeve motion due to the actuation of actuator  334  may be superimposed upon motion and actuation from the cascade  234  as previously described to produce a greater range of possible customization of the movement, stroke, and rate of the sleeve  202  compared to the cascade  234 . 
         [0028]    While some of the examples were described above in connection with a translating cascade reverser, one skilled in the art would appreciate that aspects of the disclosure may be applied in connection with any type of reverser, such as a secondary sleeve reverser and/or conventional reversers including those with fixed nozzles/trailing edges. The mechanism can be tailored for transient and deployed area match. 
         [0029]    Technical effects and benefits of the disclosure include obtaining a maximum/increased efficiency in terms of engine operation/output by minimizing/reducing drag losses. Additionally, the size/profile of one or more components/devices (e.g., a translating sleeve) may be minimized/reduced, allowing for shorter lines of travel and better/different packaging options. For example, a shorter TRAS can be used for a given thrust reverser stroke. There might not be a need to penetrate an aft ring with TRAS actuator(s), allowing for tighter/smaller packaging. 
         [0030]    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.