Abstract:
Actuators, principally for inflating emergency-usage objects such as floats and rafts, are detailed. Two opposite positive actions may be required to effect complete inflation of the objects, inhibiting inadvertent deployment of, particularly, the rafts while readily permitting deployment when intended.

Description:
REFERENCE TO PROVISIONAL APPLICATION 
       [0001]    This application is based on, claims priority to, and hereby refers to U.S. Provisional Patent Application Ser. No. 61/270,303, filed Jul. 7, 2009, the entire contents of which are incorporated herein by this reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    This invention relates to actuators and more particularly, although not necessarily exclusively, to actuators commencing inflation of emergency flotation apparatus intended for use with aircraft such as helicopters. 
       BACKGROUND OF THE INVENTION 
       [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 as well as floats for the aircraft itself. This is particularly true for certain helicopters flying over-water missions, which helicopters often contain both inflatable rafts and inflatable floats. Prior to deployment, the floats typically are mounted to landing skids of the helicopters, whereas the rafts normally are stowed inside the cabins. 
         [0004]    Should a helicopter need to ditch in water, prior to ditching the pilot typically activates the inflatable floats by pulling a handle or lever mounted to a primary flight control. Actuating inflation of the life rafts may be more difficult, however. If the rafts are stowed within the aircraft cabin, their premature inflation could injure passengers or crew or interfere with crew control of the aircraft. Similarly, premature inflation of externally-stowed rafts could result in their being displaced from the aircraft or, alternatively, becoming entangled in aircraft controls. Preventing inadvertent actuation of raft inflation systems thus is of substantial importance to aircraft passengers and crew. 
         [0005]    U.S. Pat. No. 7,314,398 to Parrott, et al. discloses certain helicopter flotation systems comprising both floats and life rafts. Indicated in the Parrott &#39;398 patent is that “[i]nflation of the floats is achieved using . . . an actuator, such as an electrical or mechanical switch, to release a canister of compressed gas into an air hose . . . and into the floats.” See Parrott &#39;398, col. 4, 11. 19-22 (numerals omitted). Inflation of the life rafts occurs likewise. See id., 11. 41-45. No further description of the actuator—or of preventing inadvertent actuation—occurs in the Parrott &#39;398 patent, however. 
         [0006]    U.S. Pat. No. 7,207,522 to Parrott, et al. discusses safety trigger devices associated with inflatable life rafts. According to the Parrott &#39;522 patent, such devices may include multiple handles, with movement of any of the handles triggering inflation of the rafts via rotation of a cam. The handles are intended to be spaced about a helicopter so that the rafts may be inflated “from a plurality of locations including the cockpit and each side o” f the helicopter. See Parrott &#39;522 at col. 1, 11. 36-38. Again, however, no description of preventing inadvertent actuation of inflation systems is made. Moreover, offering multiple actuation handles may increase, rather than decrease, the likelihood of premature inflation of the rafts. 
         [0007]    An existing pneumatic actuator of the assignee of this application includes a cockpit-located handle as well as a shear, or “breakaway,” wire. Connected between the handle and the base, the breakaway wire inhibits certain inadvertent inflation actions. Until sufficient force is applied to the handle to overcome the strength of the wire, the handle remains seated in the base, preventing actuation of inflation. 
         [0008]    Although these existing actuators of the assignee perform well, they may be subjected to instances in which crew (or passengers if in the cockpit) inadvertently apply sufficient force to the handles to break the wires. As an example of such an instance, should a strap from a camera or flight bag encircle a handle, the bag holder may attempt to detangle the strap by yanking on it. This yanking could apply momentary force to the handle greater than the strength of the breakaway wire, causing the wire to fail and the handle to extend, in turn actuating the inflation system for the raft. Need thus exists for actuators designed to diminish further the possibility of inadvertent activation by passengers or crew. 
       SUMMARY OF THE INVENTION 
       [0009]    The present invention provides such actuators. Preferred versions of the invention require two opposite actions to complete the inflation process, a pulling activity designed to inflate the floats and a pushing motion to inflate the rafts. Collectively, these actions inhibit inadvertent deployment of the actuators (especially as to the rafts) while readily permitting deployment when actually intended. 
         [0010]    A crewmember (or passenger) pulls a handle or other lever to commence the activation process. This motion actuates float inflation by piercing a first canister of inflating fluid. It also results in movement of a spring-loaded detent so as to align a bearing surface with a second piercing mechanism. Subsequent pushing of the lever causes the bearing surface to contact and move the second piercing mechanism, in turn puncturing a second canister and inflating the rafts. A roll pin or other arresting device may limit rotation of the lever when initially pulled. 
         [0011]    It thus is an optional, non-exclusive object of the present invention to provide actuators requiring multiple actions for complete activation. 
         [0012]    It is another optional, non-exclusive object of the present invention to provide actuators requiring opposite actions (e.g., pulling and pushing) for complete activation. 
         [0013]    It is a further optional, non-exclusive object of the present invention to provide actuators useful especially, although not exclusively, on-board aircraft. 
         [0014]    It is also an optional, non-exclusive object of the present invention to provide actuators useful in connection with inflating life rafts mounted in, on, or to helicopters. 
         [0015]    It is an additional optional, non-exclusive object of the present invention to provide actuators in which a person must cause float inflation prior to inflation of the rafts occurring. 
         [0016]    Other objects, features, and advantages of the present invention will be apparent to those skilled in the appropriate fields with reference to the remaining text and the drawings of this application. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]      FIG. 1  is a perspective view of an exemplary actuator of the present invention. 
           [0018]      FIGS. 2-3  are partially cut-away views of the actuator of  FIG. 1  in an initial position. 
           [0019]      FIGS. 4-7  are partially cut-away views of the actuator of  FIG. 1  in various positions allowing inflation of floats and rafts. 
           [0020]      FIG. 8  is a plan view of portions of the actuator of  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION 
       [0021]    Illustrated in  FIGS. 1-8  is exemplary actuator  10  of the present invention. Also depicted in the figures are first and second cartridges  11  and  12 , which may contain compressed gas. Such gas preferably will be used to inflate emergency equipment such as floats and life rafts, although it conceivably may be used for other purposes instead. Alternatively, either or both of cartridges  11  and  12  may be part of a pyrotechnic mechanism for generating inflation gas. Preferably, however, carbon dioxide is contained within cartridges  11  and  12 . 
         [0022]    Actuator  10  may include body  14  to which lever or handle structure  18  may be connected. Handle structure  18  preferably includes base  22  and handle  26 , the latter of which beneficially is (but need not necessarily be) an elongated object configured to be grasped by a human hand. Base  22  extends from handle  26  to facilitate connecting handle structure  18  to body  14 . 
         [0023]    Body  14  additionally may include means for mounting actuator  10  within an aircraft cockpit (or otherwise as desired). Depicted in  FIGS. 1-2  is an example of such a mounting means comprising split collar  30  and fasteners  34 . In this example, upper portion  38  of collar  30  may be fitted about the outer surface of a cylindrical object; lower portion  42  of collar  30  may too be fitted about the outer surface, following which the upper and lower portions  38  and  42  may be connected using fasteners  34 . Body  14  may include at least one, and preferably two, exhaust ports  46  and  50  (see also  FIG. 8 ) and internal channels sufficient to allow fluid communication between cartridge  11  and port  50  and between cartridge  12  and port  46 . Those skilled in relevant fields will, of course, recognize that fluid communication may occur differently than as depicted in  FIGS. 1-8 . 
         [0024]    Pin  54  connects body  14  and base  22  of handle structure  18 . Handle structure  18  may pivot about the longitudinal axis of pin  54 , allowing handle  18  to be both pulled and pushed. Removable arming pin  58  also may (initially) connect body  14  to handle structure  18 , preventing structure  18  from pivoting until the pin  58  is removed. 
         [0025]    Illustrated as present within at least one of body  14  and base  22  are first and second piercing mechanisms  62  and  66 , respectively, roll pin  70 , and detent assembly  74 . First piercing mechanism  62  includes first pin  78  configured to pierce, puncture, or otherwise encroach upon first cartridge  11  so as to release compressed inflation fluid therefrom. Similarly, second piercing mechanism includes second pin  82  configured to release compressed inflation fluid from second cartridge  12 . First and second piercing mechanisms  62  and  66  may travel within respective bores or channels  86  and  90  within body  14  between a first position (in which a respective pin is remote from a cartridge; see, e.g.,  FIG. 3 ) and a second position (in which a respective pin engages a cartridge; see, e.g.,  FIGS. 4-8 ). 
         [0026]    Roll pin  70  may be utilized to restrict rotation of handle structure  18 . Such restriction may occur in any suitable way or, if desired, not be present in actuator  10 . Likewise, other conventional means for restricting rotation may be used instead. 
         [0027]    Detent assembly  74  may comprise detent  94 , plunger  98 , and pin  100 . Preferred detent  94  may have a generally “L” shape with slot  102  present in its upstanding leg  106 . Pin  100  may be positioned within slot  102 . 
         [0028]    Detent  94  additionally may have a notch or channel into which plunger  98  may be fitted. Because plunger  98  preferably is spring-loaded, it bears against surface  102  within the channel of detent  94 . Second leg  110  of detent  94  includes surfaces  114  and  118 , the latter of which initially may contact second piercing mechanism  66  to counteract the biasing force of spring-loaded plunger  98 . 
         [0029]      FIGS. 2-3  thus illustrate actuator  10  in its normal, unactivated state. As shown, handle structure  18  is in a neutral position, not having been rotated about pin  54 . First and second cartridges  11  and  12  are intact, as pins  78  and  82  are remote therefrom. 
         [0030]    Should an emergency (or other reason) arise prompting use of actuator  10 , a pilot (or other crewmember or person) may grasp handle  26  and move it away from cartridges  11  and  12 . Because actuator  10  typically will be mounted in a cockpit and oriented with cartridges  11  and  12  remote from the pilot, the initial action of the pilot will be a pulling motion on handle  26  (see arrow “A” of  FIG. 4 ). This initial action causes handle structure  18  to rotate about pin  54 , as shown in  FIG. 4 . As handle structure  18  rotates, internal surface  122  bears against first piercing mechanism  62 , moving pin  78  toward first cartridge  11 . Eventually pin  78  breaches cartridge  11  ( FIG. 5 ), causing the compressed inflation fluid therein to be exhausted, via port  50 , to one or more inflatable objects (preferably floats). 
         [0031]    Also illustrated in  FIG. 5  is movement of detent  94  as handle structure  18  pivots about pin  54 . Such pivoting causes surface  118  no longer to bear against second piercing mechanism  66 , allowing plunger  98  to move detent  94  until the movement is arrested by pin  100 . At this point, surface  114  bears against second piercing mechanism  66 . 
         [0032]    Moving handle  26  toward cartridges  11  and  12  (see arrow “B” of  FIG. 6 ), therefore, causes surface  114  to push second piercing mechanism  66  toward cartridge  12  as detailed in  FIG. 6 . Continued pushing forces pin  82  to pierce cartridge  12  ( FIG. 7 ), causing the compressed inflation fluid therein to be exhausted through port  46  for inflation of one or more objects. These objects preferably are rafts for use by passengers or cargo of the aircraft. 
         [0033]    The present invention thus provides a two-stage inflation sequence for inflatable objects. If on-board a helicopter intending to ditch over water, for example, handle  26  of actuator  10  initially would by pulled by a pilot prior to ditching so as to activate floats for the aircraft. As ditching occurs (or soon thereafter), the pilot may push handle  26  to activate life rafts. Thus, in this example raft inflation may not occur until after floats have been inflated, reducing the risk of premature inflation of the rafts. Further, preferred versions of actuator  10  are installed on-board helicopters so that handle  26  may not be grasped until a pilot releases the primary flight control, requiring him or her to take deliberate action to utilize actuator  10 . This requirement reduces risk of inadvertent inflation of any of the inflatable objects. 
         [0034]    The foregoing is provided for purposes of illustrating, explaining, and describing embodiments of the present invention. Modifications and adaptations to these embodiments will be apparent to those skilled in the art and may be made without departing from the scope or spirit of the invention. Additionally, the contents of the Parrott &#39;398 patent and of the Parrott &#39;522 patent are incorporated herein in their entireties by this reference.