Abstract:
There is provided a new and useful fluid conduit coupling apparatus which allows quick connection and disconnection with substantially no introduction of ambient fluids or air into the process fluid. In one aspect of the invention there is provided a quick connect/disconnect coupling for a fluid conduit, the coupling comprising assemblies for attaching to the ends of a conduit to be connected and for subsequently mating together, each assembly comprising a normally closed channel; means for expelling fluid from between the assemblies when the assemblies are to be connected to each other; means for preventing fluid from entering the assemblies from outside when the assemblies are being connected; means for opening the normally closed channels, means operable by the connecting of the assemblies to each other; latch means for securing the assemblies together, the latch means disconnectable by means of a hand operated unlatching means or by the application of a predetermined tensile force.

Description:
FIELD OF THE INVENTION  
         [0001]    This invention relates to a fluid conduit coupling device which allows the simultaneous coupling or uncoupling of pairs of fluid conduits substantially without the loss of process fluid or the introduction of air or ambient fluid, and which will automatically uncouple with the application of a predetermined tensile force.  
         BACKGROUND Of THE INVENTION  
         [0002]    It is desirable to have a means of coupling and uncoupling fluid conduits such as hoses without the need to drain the hoses prior to coupling or risk fluid loss. Moreover, it is desirable to have a means to couple fluid conduits without introducing contaminants such as ambient fluids and air into the process fluid. In situations where it is foreseeable that it might be necessary to uncouple the fluid conduits very quickly, or under other circumstances preventing the use of a manually actuated release, it is desirable to have a means of disconnecting the fluid conduits by the application of a predefined amount of tensile force on the fluid conduits, preferably without damage to the conduits or the coupling, and in a manner allowing rapid recoupling without the need for prior repair. Such decoupling should occur without fluid leakage from the conduits.  
           [0003]    Such quick-connect/quick disconnect dry-break connectors are especially desirable for use with liquid-circulating personal temperature maintenance systems, particularly when such devices are used by those piloting or driving vehicles from which rapid ejection, possibly followed by reconnection, may become necessary.  
           [0004]    Numerous detachable fluid conduit coupling systems are known in the prior art. Many such devices employ spring-loaded ball-type valves which may reduce the loss of process fluid upon uncoupling. Such systems are described in U.S. Pat. No. 4,105,046 of Sturgis, and U.S. Pat. No. 5,092,364 of Mullins, both of which describe detachable fluid couplings. However, systems of this type fail to provide a means to substantially prevent the introduction of contaminants such as air and ambient fluids into the process fluid upon coupling. This is because the spring-loaded ball type valves lack a means to expel potentially contaminating materials from the valve surfaces prior to joining.  
           [0005]    U.S. Pat. No. 4,794,937 of Hoffman describes a plug and socket-type plug coupling designed for application in high pressure systems. The design of this coupling necessitates the use of gaskets recessed within the coupling apparatus and does not provide a means of expelling ambient fluids or air prior to coupling.  
           [0006]    Most fluid coupling systems are not adapted to allow damage-free separation of the connector ends upon the application of tensile force when a manual release mechanism has not been actuated. This can result in the loss of significant quantities of process fluid due to conduit rupturing when emergency separation becomes necessary. In situations where the process fluid is potentially dangerous, this can pose a substantial hazard. Moreover, should separation not occur under conditions where it is necessary the device through which fluid was being circulated may be dragged behind or into the fluid source device, resulting in injury and property damage.  
           [0007]    U.S. Pat. No. 5,529,085 of Richards et al teaches a breakaway hose coupling designed to limit the loss of process fluid upon the separation of the coupling. This design relies on the breakage of shear pins to effect release of the coupled hoses. Thus, while an emergency release system is provided, it is not a quick-connect/quick release system. Moreover, design is not adapted to exclude ambient fluid and air upon hose coupling.  
           [0008]    The most common commercially available fluid quick-connector types known to the inventors are those produced by Colder Products Company of Minnesota, U.S.A. Features of these connectors are detailed in U.S. Pat. Nos.: 4,436,125, 4,541,457, 4,911,655, 5,033,777, 5,052,725, 5,104,158, 5,126,041, 5,494,074, 5,845,943, and D357,307 and D384,712. Some connectors manufactured by Colder Products Company purport to have self-sealing valves. However, due to design factors, a substantial amount of process fluid is typically lost when these valves are uncoupled, and a substantial amount of ambient fluid or air is introduced into the process fluid upon coupling. Moreover, no Colder Products Company valve is known to the inventors which uncouples automatically upon the application of a predetermined tensile force.  
         SUMMARY OF THE INVENTION  
         [0009]    It is thus an object of the present invention to provide a fluid conduit coupling apparatus which allows quick connection and disconnection with substantially no introduction of ambient fluids or air into the process fluid.  
           [0010]    In one aspect of the invention there is provided a quick connect/disconnect coupling for a fluid conduit, the coupling comprising assemblies for attaching to the ends of a conduit to be connected and for subsequently mating together, each assembly comprising a normally closed channel; means for expelling fluid from between the assemblies when the assemblies are to be connected to each other; means for preventing fluid from entering the assemblies from outside when the assemblies are being connected; means for opening the normally closed channels, means operable by the connecting of the assemblies to each other; latch means for securing the assemblies together, the latch means disconnectable by means of a hand operated unlatching means or by the application of a predetermined tensile force. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]    These and other advantages of the invention will become apparent upon reading the following detailed description and upon referring to the drawings in which:  
         [0012]    [0012]FIG. 1 is a top view of a preferred form of a coupler according to the invention, in a disconnected state;  
         [0013]    [0013]FIG. 2 is a side view of the coupler of FIG. 1;  
         [0014]    [0014]FIG. 3 is an end view of the coupler of FIG. 1, illustrating the two ends of the coupler which are juxtaposed in FIG. 2;  
         [0015]    [0015]FIG. 4 is a cross-sectional top view of the coupler of FIG. 1 in a completely disconnected state;  
         [0016]    [0016]FIG. 5 is a cross-sectional top view of the coupler of FIG. 1 in a partially disconnected state;  
         [0017]    [0017]FIG. 6 is a cross-sectional top view of the coupler of FIG. 1 in a completely connected state;  
         [0018]    [0018]FIG. 7 is a cross-sectional side view of the coupler of FIG. 1 showing a preferred latch assembly in a completely uncoupled state;  
         [0019]    [0019]FIG. 8 is a cross-sectional side view of the coupler of FIG. 7 showing the latch assembly in an intermediate state just prior to complete coupling or complete uncouplings;  
         [0020]    [0020]FIG. 9 is a cross-sectional side view of the coupler of FIG. 7 showing the latch assembly in its completely coupled state;  
         [0021]    [0021]FIG. 10 is a cross-sectional side view of the coupler of FIG. 7 showing the latch assembly in an intermediate state immediately prior to uncoupling using the manual release button; and  
         [0022]    [0022]FIG. 11 is a cross-sectional side view of the coupler of FIG. 1 showing the securing device in a completely coupled state experiencing a moderate tensile force;  
         [0023]    [0023]FIG. 12 is a cross-sectional side view of the coupler of FIG. 1 showing the latch assembly in an intermediate state immediately preceding complete automatic uncoupling;  
         [0024]    [0024]FIG. 13 is an exploded perspective view of two halves of a coupler according to FIG. 1. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0025]    In the following description, similar features in the drawings have been given similar reference numerals. The drawings illustrate a double or twin coupling for connecting together two pairs of conduits or for inserting at an intermediate point in a pair of conduits. It should be noted that the coupling can equally be constructed for use as a single coupling in a single conduit. In that case one flow passage or channel is either not present or not used. The coupling can also be constructed as a multiple coupling for a group of conduits.  
         [0026]    With reference to FIGS.  1  to  3 , there is illustrated one preferred form of the coupler according to the invention. Thus, the coupler  10  comprises first and second parts  12  and  14  respectively which are configured to meet together, as will be discussed, and as illustrated in cross section in FIG. 6.  
         [0027]    Each of parts  12  and  14  are provided with flow passage or channel assemblies  16 ,  18 ,  20  and  22 . The channels provide flow passages through parts  12  and  14  but the flow is interruptible, as will be discussed.  
         [0028]    Each of parts  12  and  14  may include a bypass channel  23 , a primary purpose of which is to allow some circulation for maintenance of temperature uniformity in the system. Where not necessary, the bypass channels may simply be blocked or omitted. Where the coupling is constructed for use in a single conduit, no bypass will be present.  
         [0029]    Hose barbs  24 ,  26 ,  28  and  30  provide for the securing of respective conduit ends to parts  12  and  14 . Tail clamps  32  and  34 , consisting of identical parts  36  and  38 , and  40  and  42 , respectively, are secured together by means of fasteners such as screw pairs  44  and  46  to securely clamp the conduit ends to the hose barbs. In applications where safety precludes the use of screws, pins or rivets may be used.  
         [0030]    The tail clamps serve not only to secure the conduits to the coupling but may also to relieve strain as between the conduits and the channel assemblies, to provide a protective shield over bypasses  23 , and to provide a thermal and/or pressure sensor receptacle through the thermal well  25 .  
         [0031]    Part  12  includes the latch pin  138  which, upon connecting together parts  12  and  14  of coupler  10 , is inserted into a receptacle assembly  160  (refer to FIG. 7) which contains a latch plate  164 . As will be described later, the latch pin  138  locks with the latch plate  164  to secure a coupler in a connected state.  
         [0032]    The part  14  includes a manual release assembly  54  which, on application of pressure to the release button  56  causes the latch pin  138  to unlock from latch plate  164 .  
         [0033]    FIGS.  4  to  6  illustrate the flow channel assemblies in detail. As with all of the series of figures, the coupler is shown in a double configuration for insertion between two pairs of conduit ends. More particularly, the figures illustrate a form of the coupler which is preferably used as part of a supply and return system, whereby a fluid supply flows in one direction through one side of the coupler and in the opposite direction to the other side of the coupler. Thus, FIGS.  4  to  6  illustrate direction of flow by means of the arrows. Furthermore, the figures progressively illustrate the coupler in a disconnected state in FIG. 4, a partially connected state in FIG. 5, and a connected state in FIG. 6.  
         [0034]    The parts  12  and  14  of coupler  10  are the same insofar as the channel assemblies are concerned, and differ only in latch assembly  58 , in that part  12  includes latch pin  138  and associated parts, and part  14  includes receptacle assembly  160 . Since the two flow channels through the coupler are the same, it is necessary to describe in detail one side only.  
         [0035]    Thus, channel assembly  16  in part  12  comprises a channel wall  60  which houses the assembly components. Channel wall  60  is stepped on the outside thereof at  62  to provide a length  64  of decreased outside diameter extending to the end  66  of wall  60 .  
         [0036]    The inside of wall  60  is profiled to provide a part  68  of decreased inside diameter.  
         [0037]    Channel wall  60  is also stepped internally to provide a shoulder  70  adjacent end  72  of channel wall  60 .  
         [0038]    A coil spring  74  is seated within channel  76  against shoulder  70 .  
         [0039]    Closure means comprising a shuttle  78  (refer to FIG. 13) comprises a base ring  80 , a series of struts  82  and a plug  84 . Plug  84  includes a leading surface  86 .  
         [0040]    A sealing ring  88  is disposed around plug  84 , and a complimentary sealing ring  90  is fitted within area  68  of channel wall  60 .  
         [0041]    In the preferred configuration the leading surface  86  is overlaid by an elastomeric cap comprising a face seal  87  and integral sealing ring  88 .  
         [0042]    In the normal disconnected position of the coupling, as illustrated in FIG. 4, shuttle  78  is biased by spring  74  to close off the opened end of the channel. In that condition the sealing rings  88  and  90  combine to prevent fluid leakage. The face seal  87  of shuttle  78  is substantially flush with the end  66  of channel wall  60  and is held in that position by the abutment of base ring  80  against the narrowing interior of channel wall  60  at  92 .  
         [0043]    The shuttle  78  is free to move within the channel wall  60  against the force of spring  74  when sufficient force is applied to the leading surface  86  of shuttle  78 .  
         [0044]    Turning to the complimentary part  14 , the channel wall  94  has an inside diameter at end  96  which is matched to the outside diameter of channel wall  60  of part  12  at area  64 .  
         [0045]    Toward opposite end  98  of channel wall  94  the wall is stepped to form shoulders  100  and  102 . A side vent tube  104  (refer to FIG. 13) is seated against shoulder  102  and fixed to channel wall  94 . Seal  106  provides sealing as between tube  104  and shoulder  102  of channel wall  94 . Seal  106  may be omitted where side vent tube  104  is welded directly to shoulder  102 .  
         [0046]    Side vent tube  104  consists of lower tubular part  108  which actually defines within it a part of channel  110 . From the end of tubular part  108 , a group of struts  111  support plugs  112 . The struts  111  are preferably extended along the length of tubular part  108  to form reinforcing ribs. Plug  112  includes a leading surface  114 , a peripheral seal  116  and a sealing ring  117 . Preferably the leading surface  114  is flush with the end  96  of channel wall  94 .  
         [0047]    In the preferred configuration, the leading surface  114  is overlaid by an elastomeric cap which forms a face seal  115  integral with peripheral seal ring  116  and sealing ring  117 . The plug  112  preferably includes a shoulder  113  into which sealing ring  117  is molded.  
         [0048]    A coil spring  118  is disposed about tubular part  108  and seated against shoulder  100  of channel wall  94 .  
         [0049]    To complete the closure means in the channel assembly  18 , an annular slider  120  is disposed about side vent tube  104  and is freely slidable in the annulus  122  between the channel wall  94  and the tubular part  108 . Slider  120  is provided with a sealing surface  124  at one end and a sealing ring  126  at the other end. Slider  120  also includes a shoulder  128  which seats against spring  118 . When the channel  110  is in the normally closed position when the parts  12  and  14  are disconnected, as illustrated in FIG. 4, slider  120  is biased by spring  118  to a position where sealing surface  124  seals against sealing ring  117  of plug  112 , and sealing ring  126  seals against tubular part  108  to thereby prevent leakage into or out of channel  110 .  
         [0050]    Axial force exerted against the slider  120  will permit the slider to move against the biasing force of spring  118 .  
         [0051]    Without considering for the moment the latch assemblies  58 , the operation of the channel assemblies will be described with reference to the three positions illustrated in FIGS.  4  to  6 . FIG. 4 illustrates the coupler in a disconnected state in which the springs  74  and  118  respectively bias the shuttle  78  and the slider  120  into positions in which the channels are closed to the outside, so that no leakage can occur either inwardly or outwardly.  
         [0052]    When the two parts  12  and  14  are moved together axially as illustrated in FIG. 5, the first contact will be between the leading surfaces  86  and  114  of shuttle  78  and side vent tube  104  respectively. When this contact is made, any ambient fluid, whether liquid or atmospheric air, will be substantially expelled from the area between the surfaces.  
         [0053]    As parts  12  and  14  are further overlapped by additional axially movement, the end  66  of channel wall  60  moves into the annular space  130  between channel wall  94  and the leading land  132  of slider  120 . At the same time, plug  112  is forcing shuttle  78  into channel  76  against the bias of spring  74 , resulting in sealing ring  90  in channel wall  60  to be first transferred to peripheral seal  116  of plug  112  and then to engagement with the leading land  132  of slider  120 . The movement of the shuttle thus opens a flow path between struts  82  of shuttle  78  and the wall  60 . However during this motion the channels  76  and  110  are effectively sealed against inward or outward leakage at their interface by the sealing rings  90 ,  117  and  126 .  
         [0054]    As further axial movement occurs, the end  66  of channel wall  60  abuts against shoulder  134  of slider  120 . As parts  12  and  14  are forced into the connected state, the end  66  of channel wall  60  forces slider  120  to move against the bias of spring  118 . This movement of slider  120  opens the flow path between the struts  111  of side vent tube  104 , so that fluid can begin to flow through the side vents. This thus opens flow between channels  76  and  110  and effectively seals against inward and outward leakage to the ambient. At the same time, the shuttle  78  remains restrained by leading surface  114  of plug  112  and is moved further within channel wall  60  against the force of spring  74 .  
         [0055]    As is clear from FIG. 6, a flow path is also opened around the outside of plug  84  and plug  112  of shuttle  78  and side vent tube  104  respectively.  
         [0056]    When fully coupled, end  96  of channel wall  94  abuts shoulder  62  of channel wall  60 .  
         [0057]    The coupler has thus been connected in a way which prevents leakage either into or out of the unit.  
         [0058]    In disconnecting, the process is simply reversed, so that shuttle  78  and slider  120  are caused by springs  74  and  118  respectively to return to their initial positions to close off the channels to again prevent leakage in the disconnect step.  
         [0059]    Turning to FIGS.  7  to  12 , the latch assemblies  58  are illustrated in detail.  
         [0060]    The pin assembly  136  comprises latch pin  138  having a base plate  140 . A spring  142  is disposed around latch pin  138  and is seated against base plate  140 . Spring  142  is held under compression by spring retainer  144 . Thus spring  142  maintains a constant bias against base plate  140 .  
         [0061]    Base plate  140  and latch pin  138  are together slidable within the latch pin housing  146 . However, the extent of sliding movement of base plate  140  is limited on one side of housing  146  by plate  148 . Plate  148  thus acts as a stop for one side of base plate  140 .  
         [0062]    Latch pin  138  includes a shoulder  150  which is preferably formed by positioning a cone-shaped part  152  on latch pin  138 . Latch pin  152  is then extended at  154  beyond the end of cone-shaped part  152 .  
         [0063]    As is evident from the drawings, the forward area of the latch pin  138 , particularly including the shoulder  150  extends beyond the end  158  of latch pin housing  146 .  
         [0064]    Turning to receptacle assembly  160 , the receptacle housing  162  includes a latch plate or striker plate  164  which extends down into the interior of housing  162 .  
         [0065]    A manual release button  56 , disposed on the outside of receptacle housing  162 , has fixed thereto a manual release pin  168 . Button  56  is biased toward the upward position shown in FIGS.  7  to  9  and  11  to  12  in which the manual release pin  168  may be said to be in a rest position.  
         [0066]    The outer part  170  of spring retainer  144  and the latch plate  164  leave openings  172  and  174  at the entries to latch pin housing  146  and receptacle housing  162  respectively. Openings  172  and  174  are configured such that latch pin  138  can be tilted relative to the axis of the housings.  
         [0067]    The spring retainer  144  and latch plate  164  are secured in position by shear pins  176  and  178 , and  180  and  182  respectively.  
         [0068]    The operation of the latch assembly  58  is illustrated sequentially in FIGS.  7  to  12 . Those figures illustrate both manual and automatic disconnection and also illustrate a safety feature provided by the shear pins.  
         [0069]    When the parts  12  and  14  of coupler  10  are brought together, latch pin  138  extends out of the opening  172  in latch pin housing  146  and through the opening  174  in receptacle housing  162 . As the parts are moved more closely together, as illustrated in FIG. 8, the conical part  152  is deflected by latch plate  164 . The latch pin  138  is biased against deflection by spring  142  acting on base plate  140 . Because base plate  140  is free to slide within latch pin housing  146 , when latch plate  164  deflects latch pin  138 , one side  184  of base plate  140  tilts against the force of spring  142 . When shoulder  150  passes latch plate  164 , the force of spring  142  acting on side  184  of base plate  140  causes latch pin  138  to snap back to the rest position along the axis of the housing so that shoulder  150  is locked behind latch plate  164 . The coupling is now locked in the position illustrated in FIG. 9.  
         [0070]    There are three possible means of disconnecting the latch assemblies. First, the assemblies may be disconnected manually by depressing button  56  which acts through manual release pin  168  on the extended part  154  of latch pin  138 . The latch pin is then deflected to the position shown in FIG. 10. The two parts  12  and  14  could then simply be pulled apart. However, since in the connected position the springs  74  and  118  in the channel assemblies  16  and  18  are in compression, the springs will cause the two parts  12  and  14  to spring apart as soon as the shoulder  150  is caused by the release pin  168  to clear latch plate  164 . That thus describes the manual disconnection.  
         [0071]    In an emergency or other situation where unusual axial force is placed on the coupling and the conduits which are attached to it, it may be necessary to allow disconnection without manual intervention. For example, if the conduits were feeding heating fluid to a flying suit, and the pilot ejected from an aircraft, it is necessary that the conduits disconnect without impeding the pilots exit from the aircraft. The automatic disconnect feature is illustrated in FIGS. 11 and 12. As axial forces are placed on the coupler tending to disconnect it, it begins to move apart as illustrated in FIG. 11. This occurs because the base plate  140  moves axially within the latch pin housing  146 . As side  186  of base plate  140  abuts against plate  148 , continued axial force will cause base plate  140  to tilt, thus deflecting shoulder  150  of latch pin  138  out of engagement with latch plate  164 , thus allowing the coupler to spring apart under the influence of springs  74  and  118 , as described above. Once the two parts are disconnected, latch pin  138  is free to return to its rest position under the influence of spring  142 . In appropriate situations the coupler can be reconnected, since it will not have been damaged in any way by the automatic release.  
         [0072]    Finally, should the automatic release feature fail, a clean break can still be made if either pair of shear pins  176  and  178  or  180  and  182  shear off. If the first pair shear off, then the assembly within the latch pin housing  146  is free to move out of the housing. Similarly, if the second pair  180  and  182  shear, then the latch plate  164  and associated structure will move out of receptacle housing  162 . In either case there will be a successful disconnect without leakage of fluid into or out of the system.  
         [0073]    Obviously in the case of emergency release by shearing the shear pins, the coupling cannot be reconnected without repair work.  
         [0074]    Thus, it is apparent that there has been provided in accordance with the invention a coupler that fully satisfies the objects, aims and advantages set forth above. While the invention has been described in conjunction with (a) specific embodiment(s) thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications and variations as fall within the spirit and broad scope of the invention.