Abstract:
Embodiments provide systems and methods for an actuating system for inflating an inflatable structure in which a pressurized fluid piston is coupled directly to the valve an inflatable structure. The coupling of actuator to valve is such that the pairing will remain rigid and secure until the deliberate act of operating the actuator. When the actuator is operated, the actuator displaces a translating chock. This activation simultaneously (a) decouples the valve from actuator, allowing the inflatable to deploy without impedance and (b) activates the inflation of the structure via the valve.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application Ser. No. 62/129,238, filed Mar. 6, 2015, titled “Directly Coupled Valve Actuator Principally for Inflatable Structures,” the entire contents of which are hereby incorporated by reference. 
     
    
     FIELD OF THE DISCLOSURE 
       [0002]    Embodiments of the present disclosure relate generally to valve actuators for inflatable structures. Specific embodiments may find particular use in connection with inflation of emergency evacuation and/or flotation apparatus intended for use with aircraft. The valve actuators allow the source of fluid that drives activation of the valve actuator to be decoupled from the valve of the inflatable structure itself, as well as all other downstream components. 
       BACKGROUND 
       [0003]    Many aircraft carry emergency flotation devices should they cease flying while over water. Such flotation devices may include life rafts for passengers and crew, evacuation slides, as well as floats for the aircraft itself. These inflatable structures are deployed by actuation systems in which pressurized fluid is used to initiate rapid deployment of the inflatable structure. In cases where inflatable structures are installed in compartments and remote activation is advantageous or preferable, use of pressurized fluids to convey activation fluid may be employed. Under these circumstances, the mechanical energy transmitted from the control as fluid pressure will typically be converted to linear mechanical motion at the interface of the valve. This is accomplished by a piston of some type located near or adjacent to the inflatable structure&#39;s valve. The piston can, in turn, apply tension to the valve&#39;s mechanical pull cable to initiate inflation. 
         [0004]    One disadvantage to such an arrangement is that care must be taken to prevent independent motion between the piston and valve. Ordinarily, if the valve moves away from the actuator (or vice versa), the inflation may be triggered inadvertently. Furthermore, the piston, which is typically permanently connected to the tubing which acts as a conduit for the pressurized fluid, must often remain attached in some form to the aircraft or primary structure. When the inflatable structure is a life raft that must eventually depart from the compartment but remain connected to its source of inflation fluid, the valve actuator cannot remain with the primary compartment structure. 
         [0005]    One solution has been to explore electrical actuators. However, electrical actuators, although generally effective, can create challenges for airlines and/or helicopter operators when maintenance or repairs are needed. Mechanically trained technicians are usually on staff, but electrical trained specialists may not be as prevalent. If an electrical valve actuator needs repair, it can be more expensive and more time-consuming. Accordingly, mechanical valves are generally preferable. 
         [0006]    Additionally, prior deployment systems for helicopter floats (which do not detach from the structure) are inoperable in their current form for life rafts, which must detach from the structure. It is thus desirable to develop a way to maintain positioning between the valve and piston, such that the positioning between the components allows detachment when the inflatable structure departs the aircraft. The positioning should be secure, such that aircraft vibrations do not accidentally trigger activation. 
         [0007]    In previous attempts, a substantial amount of supporting structure has been required to maintain appropriate positioning of the valve and piston. This results in a rigid mounting structure for the piston and rigid guides that maintain the position of the inflation system valve until the deployment is initiated. Without such support systems, struts, or cradling, the system would potentially detach when not intended. However, the presence of such mounting structures adds expense and complexity to the valve system. 
         [0008]    The present inventors have identified a need to improve upon these arrangements. The present disclosure thus provides a valve actuator that completely decouples from the inflatable structure valve. The present disclosure provides this decoupling in a way that eliminates the need for these supporting structures. The present disclosure also provides designs that seek to reduce weight, cost, and bulk of current actuator systems. 
       BRIEF SUMMARY 
       [0009]    Embodiments provide systems and methods for an actuating system for inflating an inflatable structure in which a pressurized fluid piston is coupled directly to the valve of an inflatable structure. The coupling of actuator to valve is such that the pairing will remain rigid and secure until the deliberate act of operating the actuator. 
         [0010]    When the actuator is operated, the actuator displaces a translating chock. This activation simultaneously (a) decouples the valve from actuator, allowing the inflatable to deploy without impedance and (b) activates the inflation of the structure via the valve. 
         [0011]    In some embodiments, there is provided a valve actuator, comprising an actuator fluid inlet, an actuator housing, a piston positioned within the actuator housing and capable of slidable movement within the housing upon application of pressurized fluid to the actuator fluid inlet, a translating chock operably associated with the piston, such that translation of the piston causes corresponding translation of the translating chock, wherein the translating chock further comprises an end configured to cooperate with and secure with respect to a valve of an inflatable structure and release from the valve of the inflatable structure when translated. 
         [0012]    There may be a manual activation system associated with the chock. The piston may have a piston end comprising a tip and a shoulder, and the chock may have an opening that receives the piston tip. One or more stops to limit dislocation of the translating chock from the actuator housing may be provided. Pressurized fluid tubing may fluidly couple the valve actuator with a pressurized fluid cartridge. 
         [0013]    Other embodiments may provide a valve actuator, comprising an element that secures a valve actuator housing to a valve of an inflatable structure, wherein the element comprises a first secured position in which the valve actuator and the valve of the inflatable structure are rigidly secured, wherein the element comprises a second position in which the valve actuator and the valve of the inflatable structure are detached, the second position further causing inflation of the inflatable structure. 
         [0014]    Further embodiments may provide a method for inflating a life raft or other inflatable structure to be removed from its activation source, comprising: 
         [0015]    providing an element that secures a valve actuator housing to a valve of an inflatable structure, wherein the element comprises a first secured position in which the valve actuator and the valve of the inflatable structure are rigidly secured and a second position in which the valve actuator and the valve of the inflatable structure are detached, the second position further causing inflation of the inflatable structure; and 
         [0016]    activating the valve actuator, such that the element moves to the second position, detaching the valve actuator from the valve of the inflatable structure and causing inflation of the inflatable structure. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]      FIG. 1  shows a side perspective view of one example of a valve actuator system. 
           [0018]      FIG. 2  shows a side perspective view of an alternate valve actuator system used with an alternate valve. 
           [0019]      FIG. 3A  shows a side perspective view of the system of  FIG. 1  released from the valve. 
           [0020]      FIG. 3B  shows an exploded view of the system of  FIG. 3A . 
           [0021]      FIG. 4A  shows a side perspective view of the system of  FIG. 2  released from the valve. 
           [0022]      FIG. 4B  shows an exploded view of the system of  FIG. 4A . 
           [0023]      FIG. 5  shows a side cross-sectional view of valve system prior to actuation. 
           [0024]      FIG. 6  shows a side cross-sectional view of the valve system of  FIG. 5  upon actuation of the piston. 
           [0025]      FIG. 7  shows a side cross-sectional view of the valve system of  FIG. 5  upon a manual actuation of the translating chock. 
           [0026]      FIG. 8  shows a cross-sectional view of how the chock of the actuator is maintained in a stable configuration without multiple degrees of freedom for movement. 
           [0027]      FIG. 9  shows a side perspective view of  FIG. 8  with the chock translated. 
           [0028]      FIG. 10  illustrates an inflatable structure and its associated inflation systems. 
           [0029]      FIG. 11  illustrates inflation of the inflatable structure and its detachment from the valve actuator and aircraft. 
           [0030]      FIG. 12  provides detail of each step outlined by  FIGS. 13 and 14 . 
           [0031]      FIG. 13  shows a schematic flow chart of an activation sequence and a connection flow between elements, prior to activation. 
           [0032]      FIG. 14  shows a schematic flow chart of an activation sequence and a connection flow between elements, subsequent to activation. 
       
    
    
     DETAILED DESCRIPTION 
       [0033]    Embodiments of the present invention provide a solution to the problem of pneumatically activated inflatable structures that require substantial supporting structures to maintain alignment between the actuator piston and the inflatable structure&#39;s inflation valve. The system includes at least one source of pressurized fluid for deploying an inflatable structure and a directly coupled valve actuator that remains rigidly attached to the inflation valve until activation of a translating chock. The translating chock may be activated by the movement of a piston actuated by a pressurized fluid. In a backup situation, the translating chock may be activated manually. Once the translating chock is activated, the valve actuator is physically released from the inflatable structure valve. A separate pressurized fluid reservoir associated with the life raft or other inflatable structure then flows through the valve of the inflatable structure, causing inflation of the life raft. Release of the actuator from the valve causes inflation to begin. A further aspect disclosed relates to methods for inflating inflatable structures using the systems described herein. 
         [0034]    The disclosed embodiments may find particular use in connection with actuated valves for use with inflatables on board aircraft, but it should be understood that other alternatives are possible.  FIG. 1  shows a perspective view of an assembled actuator system  10  that uses a directly coupled valve actuator  12  to interface with an inflatable structure valve  14 .  FIG. 2  shows a valve actuator  12  interfaced with an alternate valve  16 . It should be understood that other valve styles and shapes may be used. For example, this disclosure may be used with a ball valve, a poppet valve, a cutter valve (or bayonet or zero leak valve), an inflator valve, or any other appropriate valve that is used on an inflatable structure. The embodiments in these figures illustrate the flexibility of the disclosed system  10 . The primary features and shapes may be changed based on the valve shape. For example,  FIGS. 1 and 2  provide systems that have differently shaped translating chocks  28  and primary actuator housings  22 , both of which are detailed further below. 
         [0035]    Referring now to  FIG. 1 , the actuator system  10  cooperates with a valve  14  of an inflatable structure (the inflatable structure is not shown). The system  10  features a directly coupled valve actuator  12 . The valve actuator  12  has an actuation fluid inlet  18 , a piston housing  20 , and an actuator housing  22 . The fluid inlet  18  may be fitted with a shaped or angled element  24  that can cooperate with pneumatic tubing. The pneumatic tubing can be used to deliver pressurized fluid in order to active the piston, as described further below. 
         [0036]      FIGS. 3A and 3B  show an assembled and exploded view of the system of  FIG. 1 .  FIGS. 4A and 4B  show an assembled and exploded view of the system of  FIG. 2 . Like elements are given like reference numerals, even when their shapes are varied, depending upon the specific valve shape to which the actuator  12  is fitted. As shown by the exploded views  3 B and  4 B, a piston rod  26  is positioned within the actuator housing  22 . A translating chock  28  is also positioned within the actuator housing  22 . The piston rod  26  and the translating chock  28  are generally provided in slidable cooperation. 
         [0037]    Referring now to each part more specifically, the actuator housing  22  generally has a valve cooperation face  40 . This face  40  abuts with the inflatable structure valve  14 . As illustrated by  FIG. 8 , one end  32  of the chock may extend past the valve cooperation face  40  such that it is effectively “pinned” in place with respect to the valve. This prevents movement between the valve  14  and the actuator  12  in the directions indicated by all the arrows in  FIG. 8  due to contact surfaces of the actuator  12 —at least until the translating chock  28  is translated. As described in more detail below, when the chock  28  is translated/moved as described in shown by  FIG. 9 , movement is allowed in the directions illustrated by arrows  34 , but not in the direction illustrated by arrows  36 . 
         [0038]    Referring now back to  FIGS. 1-4 , the housing  22  may also have one or more stops  42 . The stops  42  may be included to prevent the chock  28  from becoming separated from the actuator housing  22  when acted upon by the actuator piston  26  or by a manual backup tether  44 . Exemplary stops  42  may be pin stops, a back wall, a small opening in the housing that would not allow passage of the chock, or any other appropriate barrier. If provided as pin stops as shown, the stops  42  may extend through the housing  22  in order to provide a backstop to secure chock  28  in place within the housing  22  or to at least partially limit motion of the chock. The figures illustrate pin stops  42  extending across an open end  48  of the housing  22 . 
         [0039]    A manual backup tether, cable, or pull cord  44  (as shown), or a handle, T-bar, or any other appropriate manual activation system may optionally be included to allow for the inflatable structure to be inflated should the primary means of activation become unavailable. For example, the chock  28  may be activated by the manual pull feature tether  44  in the event that pneumatic or pressurized fluid inflation fails. An optional attachment slot  46  may also be included as a way to partially restrain and control the motion of the actuator during deployment. The slot  46  can effectively act as a belt loop. Slot  46  may act as a point of attachment to keep the system from moving. The slot  46  may employ webbing or other means to act as a flexible attachment to the compartment wall. 
         [0040]    The housing  22  helps support at least a portion of the actuator piston  26 . The actuator piston  26  may be housed at least in part by the actuator housing  22  and extend through and be secured with respect to a piston housing  20 . In the examples shown, the piston housing  20  may include a first piston housing element  60  that cooperates with one end of the actuation fluid inlet  18  and one end of the actuator housing  22  to complete the piston housing  20 . The actuator piston  26  is shown having a piston head  62  and a piston rod  64 . One or more seals may be present in the piston housing  20  in order to help secure the piston in place and to allow its ease of movement. 
         [0041]    The translating chock  28  is shown as having a generally L-shaped body. The chock end  32  is a shaped to cooperate with a corresponding feature  38  on the valve  16 . The corresponding feature  38  may be provided as an internal groove that would typically cooperate with a lock pin/safety pin used to prevent inadvertent actuation during maintenance or initial assembly. The chock  28  also has an opening  30  which is shaped to receive piston tip  70 . 
         [0042]    In general, the actuator piston  26  has geometry and features that allow it to remain rigidly attached within the actuator housing  22  such that it is not separable by common potential factors of inertial loads, shocks, or vibrations. The chock  28  is similarly positioned within the actuator housing  22  such that it is also not separable from the housing  22 . Once the valve actuator  12  is positioned with respect to the valve  14 , the cooperation between the valve  14  and the actuator  12  are such that the overall assembly/components remains rigidly connected. 
         [0043]    The actuator piston  26  is secured with respect to the housing and cooperates in sliding relationship with the translating chock  28 . The chock  28  similarly has geometry and features that cause it to remain rigidly attached to the inflatable structure inflation valve  14 / 16  until such time as it is forced to translate away therefrom. Movement of the chock initiates valve inflation. 
         [0044]    As illustrated by  FIGS. 5 and 6 , in use, pressurized fluid enters the actuator housing  22  through its attachment to a flexible pneumatic tubing (not shown) at the actuation fluid inlet  18 . Pressure from the incoming fluid causes the actuator piston  26  to be displaced. As illustrated by  FIG. 5 , when the valve actuator  12  is not activated, the piston head  62  is positioned in a first position—against the fluid inlet  18 . As illustrated by  FIG. 6 , when a pressurized fluid supply enters the inlet  18 , the piston  26  is forced to move away from the fluid inlet  18 .  FIG. 6  illustrates the piston  26  moving within a chamber  50  formed within the housing  22 . This piston movement, in turn, forces the translating chock  28  to also translate within the housing  22 . This translation causes the piston/chock to move to a second position. This movement is illustrated by the arrow on  FIG. 6 . 
         [0045]    Movement of the piston  26  forces related of movement of the chock  28  due to their slidable relationship with respect to one another. In a specific embodiment shown, the piston tip  70  is positioned within the opening  30  of chock  28 . Shoulders  72  on the piston abut the wall portions  52  of the chock immediately adjacent to the opening  30 . Force on the actuator piston  26  creates consequent force on the chock  28 . As shown by  FIG. 6 , when the chock end  28  has been translated away from the valve feature  38 , it releases connection of the actuator valve  12  with respect to the valve  16 . Upon completion of travel of the translating chock  28 , the valve  16  is decoupled from the actuation system  10  and is free to separate. There is no further coupling left between the valve actuator  12  and the valve  14 / 16  of the inflatable structure. This can allow the valve  14 / 16  (and the inflatable structure to which it is connected) to fully disengage from the valve actuator  12 . Once disengaged, the inflatable structure has a separate, dedicated inflation source. Movement of the chock thus causes separation of the valve actuator  12  from the valve and simultaneous activation of the inflatable&#39;s inflation source. 
         [0046]    As illustrated by  FIG. 10 , the valve actuator  12  is directly coupled to the valve  14  of the inflatable structure  100 . The inflatable structure  100  has a pressurized fluid reservoir  102  that is used for inflation. The inflatable structure  100 , along with its reservoir  102  and the directly coupled valve actuator  12 , are stored in a rigid enclosure or in a flexible (e.g., fabric) container or case  104 . Pneumatic tubing  106  may extend from the valve actuator  12  and cooperates with a pneumatic (or pressurized fluid) activation system  108 . One element of the activation system  108  may be a pressurized fluid cartridge  110 . The pressurized fluid cartridge may contain compressed CO 2 . Another element of the activation system  108  may be an activation system handle  112 . 
         [0047]    When deployment of the inflatable structure  100  is required, the activation system  108  may be activated in any appropriate manner. For example, it may be activated by a pilot or other crewmember. For example, it may be activated automatically via an accelerometer or crash sensor system. It may be activated by a water sensor, a system that uses the presence of water as an indicator to activate, or any other appropriate activation system. Activation of the activation system  108  generally causes the pressurized fluid cartridge  110  to release pressurized fluid into pneumatic tubing  106  which is delivered to the valve actuator  12 . As the pressurized fluid is delivered to the actuator fluid inlet  18  as described above, the actuator piston  26  is activated, forcing translation of the translating chock  28 . This causes the valve actuator  12  to become unpinned from the valve  14  and triggers inflation of the inflatable structure  100 . The valve actuator  12  and the pneumatic tubing  106  stay associated with the aircraft. The inflatable structure  100  with its fluid reservoir  102  begins to inflate and can detach from the aircraft, as shown by  FIG. 11 . 
         [0048]      FIGS. 12-14  shows schematically what is occurring during this activation process. As illustrated by  FIG. 12 , initially a pilot or other crewmember activates the activation system (block  1 ). This activation causes gas of a pressurized fluid cartridge to release pressurized fluid (block  2 ). The pressurized fluid flows through tubing to activate the piston of the directly coupled valve actuator  12  (block  3 ). Movement of the piston converts pressure from the pressurized fluid into mechanical translation applied to the piston into the translating chock (block  4 ). Movement of the translating chock unpins the mechanical valve of the life raft system from the directly coupled valve actuator (block  5 ).  FIG. 13  shows the coupled nature between the portions of the system located on the aircraft and the portions of the system located on the life raft system. The point at which the translating chock unpins from the mechanical valve is illustrated by  FIG. 14 . At this stage, the life raft system is free to disengage from the aircraft. 
         [0049]    Unpinning of the mechanical valve from the valve actuator triggers gas to release from the inflatable pressurized fluid reservoir (block  6 ). Pressurized fluid from the inflatable pressurized fluid reservoir flows through the mechanical valve and into the life raft inflatable, inflating the life raft for use (block  7 ). 
         [0050]    Alternatively, it is possible to actuate the actuator system  10  by application of mechanical force to the translating chock  28 . This is a secondary way to activate the system in the event that the pressurized fluid/piston option is unavailable. This redundancy may be provided for safety reasons, in the event that the fluid cartridge  110  does not work or if someone other than the pilot (or other crewmember who has access to the relevant control panel) needs to activate the system. For example, the mechanical force may be applied by a tether  44 , a cable, or any other appropriate force. This similarly causes movement of the translating chock  28 . 
         [0051]    In this manual embodiment, as illustrated by  FIG. 7 , the actuator piston  26  remains in its non-actuated state. This optional co-operable movement is due to the piston end  68  having a tip  70  and a shoulder  72 . The piston tip  70  extends through and into an opening  30  on the chock  28  that is sized to receive the piston tip  70 . The piston shoulder  72  is sized to be larger than the opening  30 , such that when piston is forced in the direction of the arrow on  FIG. 6 , the shoulder  72  abuts the chock  28  and forces its movement in the same direction. However, if a separate mechanical force is applied to the chock  28 , the chock  28  slides away from the piston in the direction of arrow on  FIG. 7 , but the actuator piston  26  remains unmoved. In  FIG. 7 , upon completion of travel of the translating chock  28 , the valve  16  is similarly decoupled from the valve actuator  12  and is free to separate. 
         [0052]      FIGS. 8 and 9  illustrate one example of the rigidity and secure positioning provided by the valve actuator  12 . These figures illustrate the relative degrees of freedom prior to and subsequent to actuation between the actuator and the valve.  FIG. 8  illustrates the degrees of freedom between the actuator and valve in a secured/coupled state.  FIG. 9  illustrates the degrees of freedom between the actuator and the valve when the chock is translated out of the valve. 
         [0053]    Prior to actuation, the system is fully constrained and no motion (or rotation) is allowed between the valve and actuator  12 . The rigid translating chock  28  (and the chock end  32 , illustrated by the cut-away view in  FIG. 8 ) is enclosed on all sides except for the sides previously constrained by the actuator housing. No motion is allowed in the direction of arrows  36  on  FIG. 8 . The valve is pinned from motion with respect to the directly coupled valve actuator  12  in all directions (except for the translating chock direction). The result is that the valve is locked from motion due to cooperating contact of the surfaces between the valve and the actuator  12 . Subsequent to actuation, after the chock has translated as described, activating the valve, the restrictions of the translating chock (as shown by arrows  34  on  FIG. 9 ) are removed, leaving only the arrow  36  restrictions present (shown as arrows  36 ), due to the actuator housing. The directions  36  that were previously pinned from motion are now freed. The cooperating surfaces between the valve and the valve actuator  12  are insufficient to restrain the valve. This allows the valve to readily separate from the valve actuator. 
         [0054]    Other variations of this design are possible and considered within the scope of this disclosure. The general concept is that the valve remains fully constrained prior to actuation and only partially constrained after the actuation process. 
         [0055]    The valve&#39;s degrees of freedom with respect to the actuator housing  22  is thus restricted by the rigid translating chock  28 . The rigid translating chock  28  replaces the function of the valve&#39;s typically-used mechanical pull cable. The translating chock  28  will remain fixed in place until it is acted upon by the actuator piston  26  within the actuator housing  22 . When the valve and valve actuator cooperate as described, the arrangement removes any freedom of relative motion between the valve and the valve actuator. This configuration can avoid the need for an external support structure. This can consequently result in an easier and more streamlined packing of the inflatable structure. 
         [0056]    Regardless of whether the translating chock  28  is activated by movement of the actuator piston  26  or is acted upon by a manually operated tether, once acted upon, the translating chock  28  will translate out of the valve  14 , thereby causing inflation of the life raft. This movement simultaneously removes the restrictions of motion between the parts and allows the valve  14  to easily slide out and away from the actuator housing  22 . 
         [0057]    It should be understood that the examples provided above are only possible utilizations of the present disclosure, and many alternatives and permutations may be realized depending on the specific valve to be interfaced to and other size and shape constraints that may be inherent to solving a designer&#39;s specific end-use application. For instance, in some cases it may be advantageous for the piston rod and rigid translating chock to be combined into a single component. Another potential variant may employ reversing the motion of the piston rod and have the chock attached to the piston via a pivoting lever or similar mechanism. Another potential variation may rotate the position of the valve actuator with respect to the valve. 
         [0058]    The present disclosure can be adapted to most mechanically activated valves with appropriate skill of the designer to accommodate the specific valve&#39;s contours and features. The present disclosure offers advantages for inflatable structures that are activated by pneumatics or other pressurized fluid filled tubing. The disclosure allows for simplifying design considerations of the related supporting structures because rigid members that would normally be required to maintain the positions of the valve and pneumatic components can be eliminated. This can provide effective design solutions that are lighter, less expensive, and easier to maintain and assemble compared to solutions which do not employ the present invention. 
         [0059]    Changes and modifications, additions and deletions may be made to the structures and methods recited above and shown in the drawings without departing from the scope or spirit of the disclosure or the following claims.