Abstract:
An exemplary suppressant actuator assembly includes a release member movable from a first position that restricts flow of a suppressant to a second position that permits flow of a suppressant. A biasing member moves from a more-biased position to a less-biased position to move the release member from the first position to the second position. A solenoid is activated to permit movement of the biasing member.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This disclosure claims priority to U.S. Provisional Application No. 61/514145, which was filed on 2 Aug. 2011 and is incorporated herein by reference. 
     
    
     BACKGROUND 
       [0002]    This disclosure relates to suppressants and, more particularly, to a suppressant actuator having a biasing member and a solenoid. 
         [0003]    Suppression systems, such as fire suppression systems, include a suppressant. Moving an actuator of these systems to an open position releases the suppressant. The released suppressant may be used to extinguish or suppress a fire. Suppression systems operate in many environments. 
         [0004]    Many fire suppression systems include pyrotechnic-based piston actuators. Such actuators are particularly prone to wear due to environmental conditions. Thus, to avoid actuator faults, the pyrotechnic-based piston actuators are periodically inspected and replaced. Inspection and replacement is costly. 
       SUMMARY 
       [0005]    An exemplary suppressant actuator assembly includes a release member movable from a first position that restricts flow of a suppressant to a second position that permits flow of a suppressant. A biasing member moves from a more-biased position to a less-biased position to move the release member from the first position to the second position. A solenoid is activated to permit movement of the biasing member. 
         [0006]    An exemplary suppression system includes a controller and a supply of a suppressant. A release member is moveable from a first position to a second position. The second position permits more flow of the suppressant from the supply than the first position. A biasing member moves from a more-biased position to a less-biased position to move the release member from the first position to the second position. A solenoid is activated in response to a command from the controller to initiate movement of the biasing member from the more-biased position to the less-biased position. 
         [0007]    An exemplary method of activating a suppression system includes activating a solenoid to permit movement of a biasing member. The method then uses the biasing member to move a release member from a first position that restricts flow of a suppressant to a second position that permits flow of a suppressant. 
     
    
     
       DESCRIPTION OF THE FIGURES 
         [0008]    The various features and advantages of the disclosed examples will become apparent to those skilled in the art from the detailed description. The figures that accompany the detailed description can be briefly described as follows: 
           [0009]      FIG. 1  shows a schematic view of an example suppression system. 
           [0010]      FIG. 2  shows a section view of an example suppressant actuator assembly used in the  FIG. 1  system in an unreleased position. 
           [0011]      FIG. 3  shows a second view of the  FIG. 2  suppressant actuator assembly in a released position. 
           [0012]      FIG. 4  shows an example detailed view of the supply and actuator in the  FIG. 1  suppressant system. 
           [0013]      FIG. 5  shows a close-up view of the area labeled as “FIG.  5 ” in  FIG. 2 . 
       
    
    
     DETAILED DESCRIPTION 
       [0014]    Referring to  FIG. 1 , an example suppression system  10  includes a suppressant actuator assembly  14  that controls flow of a stored suppressant  18  from a supply  22  in a second position. The supply  22  and the actuator  14  are together considered a fire extinguisher, for example. 
         [0015]    The suppressant actuator  14  moves a release member  56  ( FIG. 2 ) between a first, unreleased position in which suppressant  18  is stored under pressure and opening  20  within the supply  22  is closed, and a second, released position, in which opening  20  is open. The release member  56  may be part of or connected to a piston assembly  24 . The piston assembly  24 , for example includes the structures extending from the actuator  14  to the opening  20  of the supply  22 . In some examples, the piston assembly  24  may be a single structure. 
         [0016]    The movement of the piston assembly  24  between the first position and the second position is controlled through a controller  26  that sends an electrical signal to the suppressant actuator  14  to move the piston assembly  24  ( FIG. 2 ) from the first position to the second position. The controller  26  may send the electrical signal in response to various events. In one example, the controller  26  initiates movement in response to a particular thermal energy level. In another example, the controller  26  initiates movement based on a visual detection of a fire. In still other examples, the controller  26  initiates release of the suppressant  18  in response to a manual command from an operator. 
         [0017]    In moving the release member  56  from the first position to the second position, the release member  56  moves the piston assembly  24  such that an opening  20  in the supply  22  is established, allowing the pressurized, stored suppressant  18 , within the supply  22  to release suppressant  18   a  through the opening  20 , for example into an engine bay  30 . 
         [0018]    In this example, the suppressant actuator  14  is a single-use actuator that moves the piston assembly  24  from the first position to the second position one time only. In other examples, the suppressant actuator  14  moves the piston assembly  24  back and forth between first position and the second position as well as to mid-positions between the first and second positions. 
         [0019]    While the suppressant actuator  14  is shown in  FIG. 1  as extending partially outside of the supply  22  and separate from the piston assembly  24 , alternatively, the actuator  14  and the supply  22  may be joined as a single unit that is placed completely inside of or within the supply  22 . 
         [0020]    The suppression system  10  of  FIG. 1  may be held within an engine bay  30  of a vehicle  34 . Suppressant  18   a  released from the supply  22  extinguishes fires within the vehicle  34  and particularly within the engine bay  30 . In other examples, the suppressant actuator  14  is used in a crew bay, dry bay, or externally to a vehicle  34 . The suppression system  10  may suppress explosions as well. 
         [0021]    The suppressant  18  may take many forms. In one example, the suppressant includes dry chemicals. In other embodiments, the suppressant may include liquid, foam or gaseous suppressants. 
         [0022]    Referring now to  FIGS. 2-5  with continuing reference to  FIG. 1 , the example suppressant actuator  14  includes a solenoid assembly  50  and a biasing assembly  54 . The biasing assembly  54  of the present invention preferably includes a biasing member  62 , a radial flange  74 , a plurality of ball bearings  112 , and a release member  56 . A first end  29  of the piston assembly  24  is received within the suppressant actuator  14  and is connected to the release member  56 . 
         [0023]    When the release member  56 , connected to the piston assembly  24 , is moved to the second position by the suppressant actuator  14 , a second end portion  144  of the piston assembly  24  is forced through rupture disk  148  to create a hole  20 . The stored suppressant  18  then escapes from the supply  22  through the hole  20  in the rupture disk  148 . 
         [0024]    The solenoid  51  of the suppressant actuator  14  maintains the position of the release member  56  and thus the position of the piston assembly  24  until the controller  26  sends an electrical signal to the solenoid  51 . 
         [0025]    The suppressant actuator  14  of the present invention has an outer housing  66  defining a bore  12 . Slidably received within the first end of the bore  12  is a release member  56  which is connected to piston assembly  24 . The release member  56  has a radial flange  70  connected to a neck portion  21  and a stem portion  82 . A portion of the first end  29  of the piston assembly  24  extends within a bias spring bore  23  in the neck portion  21  of the release member  56 . The bias spring bore  23  is connected to a cavity  25  that extends a length of the stem portion  82  of the release pin  56 . A compressed bias spring  9  is present within the bias spring bore  23  with a first end of the spring  9   a  in contact with the piston assembly  24  and the second end  9   b  of the bias spring  9  in contact with a pin guide  8  slidably received within the bias spring bore  23 . Integrally connected to the pin guide  8  is a bias pin  7  which extends a portion of the length of the cavity  25  of the stem portion  82  of the release member  56 . An end of the stem portion  82  is slidably received by a bore  27  defined by the stem portion  88  of the header  78  of the radial flange  74 . 
         [0026]    A biasing member  62  surrounds the neck portion  21  and stem portion  82  of the release member  56 , as well as the header  78  of the radial flange  74 , with a first end  62   a  of the biasing member  62  in contact with the radial flange  70  of the release member  56  and a second end  62   b  of the biasing member  62  in contact with the radial flange  74 . The biasing member  62  moves the release member  56  outward from the housing  66 , or in the direction of D, while the second end  62   b  of the biasing member  62  remains remaining stationary and in contact with the radial flange  74 . The radial flange  74  prevents the firing pin  104  from ever contacting the biasing member  62 , regardless of the position of the firing pin  104 . 
         [0027]    The biasing member  62 , which is, in this example, a coil spring, is preferably capable of exerting between 350 and 405 pounds-force (1557 and 1802 Newtons). In alternative embodiments, other types of biasing members with their own output forces may be used. 
         [0028]    Within a second end of the bore  12  is a solenoid assembly  50 . The solenoid assembly  50  includes a solenoid  51  with at least one coil  136  connected to a power source, such as a controller  26 , a bobbin  140 , and a moveable plunger  132 . The moveable plunger  132  receives a head  128  connected to a pull end  17  of a firing pin  104 . Opposite of the head  128  of the firing pin  104  is a rod end  16  which is received by the cavity  25  within the stem portion  88  and the bore  27  defined by the header  78  of the radial flange  74 . 
         [0029]    The pull end  17  of the firing pin  104  has a first outer diameter D 1  and the rod end  16  has a second outer diameter D 2 . The transition between the first outer diameter D 1  and the second outer diameter D 2  is made through a ramp section  122 . The first outer diameter D 1  is greater than the second outer diameter D 2 . A plurality of ball bearings  112  slide from the first outer diameter portion D 1 , down the ramp section  122  to the second outer diameter portion D 2  as the firing pin  104  is moved. 
         [0030]    Bores  108  are defined in the stem portion  82  and each receive one of a plurality of ball bearings  112 . The bores  108  extend radially from the bore  100  to an outer wall of the stem portion  82  ( FIG. 4 ). When the ball bearings  112  are positioned within the bores  108 , the radially outer portions  116  of the ball bearings  112  contact the flange  74  of the header  78  to hold the piston assembly  24  in the first position. 
         [0031]    The firing pin  104  holds the ball bearings  112  within the bores  108  and against the header  78  when the piston assembly  24  is in the first, unreleased position. In this example, when the piston assembly  24  is in the first, unreleased position, the radially outer portions  116  of the ball bearings  112  contact an angled face  120  of the flange  74 . The angled face  120  is angled relative to an axis of the actuator assembly  14 . The first, unreleased position may also be considered a locked position. 
         [0032]    As can be appreciated, the biasing member  62 , when compressed, biases the piston assembly  24  in a direction D away from the header  78 . The ball bearings  112  positioned in the bores  108  limit movement of the biasing member  62  to prevent movement of the piston assembly  24  in the direction D. Specifically, contact between the radially outer portions  116  of the ball bearings  112  and the angled face  120  of the header  78  limits movement of the piston assembly  24  toward the second position. 
         [0033]    When the suppressant actuator  14  moves the release member  56  to the unreleased position as shown in  FIG. 2 , the radial flange  70  of the release member  56  is not in contact with the end of the bore  12  of the outer housing  66  and the biasing member  62  is compressed. The rod end  16  of the firing pin  104  biases the bias pin  7  and the pin guide  8  connected to the piston assembly  24 , further compressing the bias spring  9 . The plurality of ball bearings  112  are held in place on the first outer diameter portion D 1  of the firing pin  104  by friction seating on both the ramp section  120  of the radial flange  74 , ramp section  122  of the firing pin  104  and the stem portion  82  of the release member  56 . The unreleased position may also be considered an unlocked position. 
         [0034]    To release the mechanism from an unreleased position to a released position as shown in  FIG. 3 , at least one coil  136  of the solenoid assembly  50  is energized. This pulls the moveable plunger  132  opposite the direction of D in the figure, pulling the head  128  of the pull end  17  of the firing pin  104  also in a direction opposing or opposite direction D. This motion allows the plurality of ball bearings  112  to move from the first outer diameter portion D 1 , of the firing pin  104  down the ramp section  122  to the second outer diameter portion D 2  of the firing pin  104  and off of the ramp section  120  of the radial flange  74 . The movement of the firing pin  104  in the direction opposing direction D, allows the pin guide  8  to also move in a direction opposing direction D. At the same time, the biasing member  62  biases the release member  56  and piston assembly  24  in the direction of D until the radial flange  70  of the release member  56  is in contact with the end of the bore  12 . 
         [0035]    It should be noted that the biasing member  62  remains compressed by a frictional force transmitted through the plurality of ball bearings  112  that are positioned between the firing pin  104 , release member  56  and the radial flange  74 . The release member  56 , while compressed, is generating a force that is trying to pull the entire release member  56  outward. This force vector creates a reaction force at the ramp section  120  located on the radial flange  74 . The vertical component of this force vector acting upon the plurality of ball bearings  112  creates a frictional force that inherently locks the biasing member  62  in the compressed position. 
         [0036]    To reset the mechanism from a released position to an unreleased position, the mechanism needs to be manually reset. To reset the mechanism, the biasing member  62  and release member  56  must be compressed back to its initial position as shown in  FIG. 2 . By moving the release member  56  to its initial position, the bias spring  9  and firing pin  104  are also moved back to the initial position shown in  FIG. 2 . While the release member  56  is moving back to the initial position, the plurality of ball bearings  112  remain in place until they contact the ramped section  122  of the firing pin  104 . The ramped section  122  of the firing pin  104  and the movement of the release pin  56  forces the plurality of ball bearings  112  over the ramp section  122  of the firing pin and ramp section  120  of the radial flange  74 , locking the plurality of ball bearings  112  in place on the first outer diameter portion D 1 . 
         [0037]    It should be noted that the force of the bias spring  9  aids the solenoid assembly  50  by providing a spring force through bias spring  9  that is in the same direction as movement of the moveable plunger  132  of the solenoid assembly  50 . This positive net force reduces the work the solenoid assembly  50  must perform. The additional force provided by the bias spring  9  also allows the force output from the solenoid to be reduced and thus the size of the solenoid can be significantly reduced. In other words, the bias spring  9  acts as a force equivalent of a counterbalance, where a small amount of force has a large impact. 
         [0038]    The suppressant actuator  14  of the present invention provides numerous advantages over conventional actuator designs. For example, the suppressant actuator of the present invention has a fast solenoid response time of approximately 4 milliseconds (ms) with the bias spring in comparison to a conventional design without a bias spring of 25 ms. A higher force output over long distances is also present within the present invention, with a force of 5 pounds-force (22 Newtons) needed in comparison to a conventional design without a bias spring of 30 pounds-force (133 Newtons). The force of the mechanism of the present invention is 425 pounds-force (1890 Newtons) of stored force, actuated with a solenoid output force of 5 pounds-force (22 Newtons). Furthermore, the mechanism of the current invention has a stroke that ranges in excess of 0.500 inches (12.7 millimeters). The power consumption of this embodiment is approximately 120 watts, in comparison to 160 watts for a conventional design without a bias spring. In addition, the package size can be made as small as approximately 0.8 inches (20.32 millimeters) in diameter by 0.8 inches (millimeters) in length. 
         [0039]    The example suppressant actuator  14  includes four of the ball bearings  112  circumferentially surrounding the firing pin  104 . In this example, the ball bearings  112  are evenly circumferentially spaced. For example, one of the ball bearings  112  is at a 12:00 position, another at a 3:00 position, etc. 
         [0040]    In this example, the biasing member  62  and piston assembly  24  move along a common axis. 
         [0041]    The example rupture disk  148  is relatively thin and hermetically seal welded to the supply  22 , which is a cylindrical tank in this example. In one example, the suppressant actuator  14  is threaded into a fitting of the supply  22  and then hermetically seal welded to the supply  22  at areas W 1  and W 2 . Various connectors are then secured to the suppressant actuator  14 , such as MIL-DTL style round connectors or automotive-based connectors that terminate at a flying lead. 
         [0042]    In this example, the housing  66  of the biasing assembly  54  is made of a 304L stainless steel, and the housing  140  is a 430FR stainless steel. The housing  140  is welded to the housing  66  at the areas W 1  and W 2 . The housing  66  and the housing  140  each provide a radial flange to facilitate the hermetic seal. Other materials are used in other examples. 
         [0043]    Sizes of the example suppressant actuator  14  are determined based on calculations of the balancing forces, strokes, reaction times, and package size requirements for the suppressant actuator  14 . In some examples, tighter tolerances are used, and the mating surfaces are hardened or ceramic coated to reduce friction. 
         [0044]    The example suppressant actuator  14  outputs 3.7 Joules of energy. Other designs provide 9-10 Joules of energy. 
         [0045]    Features of the disclosed examples include a suppressant actuator that experiences relatively little performance degradation due to environmental conditions. The service life of some of these examples approaches 30 years, which greatly reduces the replacement intervals over prior art actuators. The example suppressant actuator has a relatively small size and provides a linear actuation. 
         [0046]    The preceding description is exemplary rather than limiting in nature. Variations and modifications to the disclosed examples may become apparent to those skilled in the art that do not necessarily depart from the essence of this disclosure. Thus, the scope of legal protection given to this disclosure can only be determined by studying the following claims.