Abstract:
A quick connect fitting is provided for connecting a pressure fluid container to an intake port of a consumer system, such as a fuel cell stack. The fitting includes a solenoid-activated valve for controlling outflow of fluid from the pressure fluid container. The valve is biased to a closed position when no electrical power is supplied to the solenoid. In one embodiment the fitting incorporates a coupling mechanism for removable attachment to the intake part of the consumer system.

Description:
FIELD OF THE INVENTION 
     This invention relates to a valve system for a pressurized fluid container, such as a bottle or tank containing hydrogen gas under pressure. It also relates to a container incorporating the valve system and a connection system for connecting one or more of the containers to a gas intake port, such as a gas intake manifold of a fuel cell system. 
     BACKGROUND OF THE INVENTION 
     Hydrogen is typically stored as a compressed gas in a suitable container which is pressurized and equipped with an external valve to turn the supply of gas from the container on and off. 
     In order to facilitate connection of the container to, say, a gas intake manifold of a fuel cell system, so-called quick coupling mechanisms or quick connectors may be considered. One such quick connector comprises mutually engaging (bayonet type coupling) male and female members to provide a gas tight seal when engaged. Typically, the male member is provided on the container and the female member is provided on the manifold or more specifically, a support rail of the manifold. When in the engaged position, gas can flow from the container through the manifold and into the system for which it is required. 
     The disadvantage of this arrangement is that, if a connector has a slow leak, the contents of the container will leak away, even if the system is not in operation. Apart from resulting in the wastage of fuel, the accumulation of a gas such as hydrogen in air produces a combustible mixture which can result in an explosion if exposed to a spark or other ignition means. 
     SUMMARY OF THE INVENTION 
     According to the invention there is provided a quick connect fitting for a pressure fluid container, the fitting comprising a solenoid-activated valve for controlling outflow of fluid from a pressure fluid container, the valve having a valve body defining a chamber therein and means for connecting the valve body to a pressure fluid container with the chamber in communication with the interior of the pressure fluid container, and further comprising a valve opening in the chamber for permitting the outflow of fluid from the container through an external fluid outlet on the valve body which external fluid outlet is in communication with the valve opening, a solenoid and an armature for activation by the solenoid, a reciprocal valve stem provided with a valve seal for closing the valve opening to the flow of fluid therethrough, the stem being connected to the armature for movement of the stem to open the valve opening when electrical power is supplied to the solenoid, and wherein the solenoid has a first terminal which is connected to an electrical conductor located on the exterior of the valve body and electrically insulated from the valve body and a second terminal which is in electrical communication with the valve body for grounding the solenoid to a pressure container to which it is connected. 
     The valve body may be provided with a coupling member for connecting the external fluid outlet on the valve body to a fluid intake port of a consumer system to which the fluid is to be supplied, the coupling member being for engagement with a mating coupling member on the intake port. 
     The electrical conductor on the exterior of the valve body may be arranged for contact with an electrical conductor on the intake port upon engagement of the coupling member with the mating coupling member on the intake port. 
     The fitting may further comprise a coupling mechanism for connecting the external fluid outlet on the valve body to the fluid intake port of a consumer system to which fluid is to be supplied, wherein the coupling mechanism comprises first and second mutually engaging coupling members, the first coupling member being located on the valve body and the second coupling member being located on the fluid intake port. The intake port may be one of a plurality of inlet ports on a manifold for receiving a plurality of the containers. 
     According to another aspect of the invention there is provided a quick connect fitting for a pressure fluid container, the fitting comprising a solenoid-activated valve for controlling outflow of fluid from a pressure fluid container, the valve having a valve body defining a chamber therein and means for connecting the valve body to a pressure fluid container with the chamber in communication with the interior of the pressure fluid container, and further comprising a valve opening in the chamber for permitting the outflow of fluid from the container through an external fluid outlet on the valve body which external fluid outlet is in communication with the valve opening, a solenoid and an armature for activation by the solenoid, a reciprocal valve stem provided with a valve seal for closing the valve opening to the flow of fluid therethrough, the stem being connected to the armature for movement of the stem to open the valve opening when electrical power is supplied to the solenoid, and further comprising a coupling mechanism for connecting the external fluid outlet on the valve body to a fluid intake port of a consumer system to which fluid is to be supplied, wherein the coupling mechanism comprises first and second mutually engaging coupling members, the first coupling member being located on the valve body and the second coupling member being located on the fluid intake port and wherein the solenoid-activated valve is located upstream of the coupling mechanism. 
     According to a further aspect of the invention there is provided a container for storing a fluid under pressure, including a solenoid-activated valve for controlling outflow of fluid from the container, the valve comprising a chamber which is in communication with the interior of the container, a valve opening in the chamber for permitting the outflow of fluid from the container through an external fluid outlet on the container which is in communication with the valve opening, a solenoid and an armature for activation by the solenoid, a reciprocal valve stem provided with a valve seal for closing the valve opening to the flow of fluid therethrough, the stem being connected to the armature for movement of the stem to open the valve opening when electrical power is supplied to the solenoid, wherein the solenoid has a first terminal which is connected to an electrical conductor located on the exterior of the container and electrically insulated therefrom, and a second terminal which is in electrical communication with the container. 
     According to another aspect of the invention there is provided a container for storing a fluid under pressure, including a solenoid-activated valve for controlling outflow of fluid from the container, the valve comprising a chamber which is in communication with the interior of the container, a valve opening in the chamber for permitting the outflow of fluid from the container through an external fluid outlet on the container which is in communication with the valve opening, a solenoid and an armature for activation by the solenoid, a reciprocal valve stem provided with a valve seal for closing the valve opening to the flow of fluid therethrough, the stem being connected to the armature for movement of the stem to open the valve opening when electrical power is supplied to the solenoid, and further comprising a coupling mechanism for connecting the external fluid outlet on the container to a fluid intake port of a consumer system to which fluid is to be supplied, wherein the coupling mechanism comprises first and second mutually engaging coupling members, the first coupling member being located on the container and the second coupling member being located on the fluid intake port and wherein the solenoid activated valve is located upstream of the coupling mechanism. 
     Further objects and advantages of the invention will become apparent from the description of preferred embodiments of the invention below. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a pressurized gas container and shows a quick connector which is in an unengaged position. 
     FIG. 2 is a view similar to FIG. 1 but showing the quick connector in an engaged position. 
     FIG. 3 is a view similar to FIG. 1 but showing an exploded view of a valve mechanism of the pressurized gas container. 
     FIG. 4 is a cross-sectional view on a larger scale showing more detail of the valve of FIG.  3 . 
     FIG. 5 is another perspective view of a pressurized gas container showing detail of an electrical contact mechanism for powering the valve mechanism. 
     FIG. 6 a  is a perspective view showing an alternative method of connecting a pressurized gas container to a gas intake manifold. 
     FIG. 6 b  is a perspective view in the opposite direction to that of FIG. 6 a.    
     FIG. 6 c  is a cross-sectional view of a quick connect fitting for the pressurized gas container of FIG. 6 a.    
     FIG. 7 is a diagrammatical illustration showing a connection system for a plurality of pressurized gas containers to a gas intake manifold. 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Referring to FIGS. 1 and 2, reference numeral  8  indicates a pressurized hydrogen gas container provided with a quick connect fitting  9 . Reference numeral  10  generally indicates a quick connector for coupling the fitting  9  to a gas intake manifold  52  (FIG. 6 a ), only a coupling  12   b  to the manifold  52  being shown in FIGS. 1 and 2. Container  8  contains a metal hydride adsorbent such that hydrogen can be stored therein at pressures closer to atmospheric. 
     The quick connector  10  comprises a male member  11 , provided on the fitting  9 , and a female member  12 , which is mounted on a supporting rail (not shown in FIGS. 1 and 2) of the manifold  52 . As can be seen, the male and female members  11 ,  12  are provided with mutually engaging formations which can be locked together in bayonet fashion by relative rotation of the members  11 ,  12 . In the present example, the female member  12  is rotatable about a longitudinal axis which corresponds with the longitudinal axis of the container  8  when the members  11 ,  12  are aligned for mutual engagement. The female member  12  is provided with a locking arm  18  for facilitating rotation of the member  12 . 
     The fitting  9  comprises a valve  20  which is upstream of the quick connector  10 , as shown in FIGS. 3 and 4. The valve  20  has a body  22  of aluminum, brass or other suitable conductive material which is screwed into the opening of the container  8 . The body  22  has an inner chamber  24  which is in communication with the inside of the container  8 . The chamber  24  is provided with a valve opening  26  through which gas can be discharged from the container  8 . 
     The valve  20  further has a valve stem  28  with a seal  30  at one end thereof. As can be seen, the stem  28  extends through the valve opening  26  so that the seal  30  co-operates with the opening  26  for opening and closing the valve  20  to gas flow. 
     The stem  28  extends through the centre of a solenoid or coil  32  and an armature  34  is located on the other end of the stem  28 . The stem  28  is biased to a closed position (i.e. in which the seal  30  is seated on the opening  26 ) by means of a spring  36  which is coiled around the stem  28 . Therefore, the valve  20  is automatically in the closed position when no electrical power is provided to the coil  32 . When power is provided, the magnetic field generated by the coil  32  attracts the armature  34 , thereby opening the valve  20 . 
     Provision for an electrical connection to the coil  32  is by means of an electrically conductive slip ring  38  provided around the outside of the valve body  22  and insulated therefrom by insulating sleeve  39 . An electrical wire connection  40  extends between the slip ring  38  and one end of the coil  32 . The other end of the coil  32  is grounded to body  22  and hence to container  8  which is also metallic and conductive. 
     The external opening of body  22  is covered with body plug  41 . Body plug  41  has a central opening containing porous sintered filter  45  through which hydrogen gas can flow out from container  8 . O-ring  43  provides a gas tight seal between body plug  41  and body  22 . Body plug  41  also has an o-ring groove  47  formed on its outside face to locate and provide a sealing surface for an o-ring seal in female member  12  of quick connector  10 . The outside face presented by body plug  41  and filter  45  is therefore almost flat. Thus, any debris or contaminants on this outside face can be readily cleaned off before connecting container  8  to manifold  14  (e.g. in the event that a disengaged container  8  was dropped in sand or the like). 
     Female member  12  comprises a rotatable outer latch body  12   a  and fixed inner coupling  12   b . On the face of the fixed inner coupling is o-ring  12   c  which mates with o-ring groove  47  on body plug  41 . Internal spring  12   d  is provided between latch body  12   a  and inner coupling  12   b . Internal spring  12   d  provides the force to sealingly engage inner coupling  12   b  to body plug  41  when quick connector  10  is engaged. 
     As shown in FIG. 5, a contact finger  42  of an electrically conductive material is provided on the female member  12  of the quick connector  10  to provide an electrical connection with the slip ring  38 . 
     The finger  42  is electrically insulated from the member  12 , which latter member is of a suitable conductive material, such as copper or brass. As can be seen, the one end of the finger  42  is shaped so that it is in contact with the slip ring  38  when the quick connector  10  is engaged. In the present example, a positive charge of 12 V is applied to the coil  32  through the slip ring  38  while the coil  32  is grounded to the container  8 , through the body  22  of the fitting  9 . 
     In the embodiment shown in FIGS. 6 a, b , and  c , a pin type connection  50  is shown as an alternative to the quick connector  10  of FIGS. 1 to  5 . FIG. 6 a  shows a perspective view of a manifold  52  and plastic frame  90  which is provided with three connectors  54 , each of which can be coupled to a container  8 . Each connector has a tubular projection  56  (not visible in FIG. 6 a ) for engaging with an opening  58  provided on container fitting  92 . Container  8  is held in position against connector  54  and frame  90  by any suitable means, such as a cam (not shown) which presses against the bottom of container  8 . In this example electrical contact is through an annular conductor  59  surrounding the opening  58 . A mating electrical contact finger  94  feeds through frame  90  to contact annular conductor  59 . FIG. 6 b  shows an opposite perspective view to that of FIG. 6 b  illustrating projections  56 . (Frame  90  is not shown in FIG. 6 b  for clarity). 
     A cross-sectional view of fitting  92  is shown in FIG. 6 c . In the embodiment of FIGS. 6 a  to  c , two valves in series are provided in fitting  92 : an electrically operated solenoid valve  70  and a mechanically operated quick connect valve  71 . Solenoid valve  70  comprises body  73 , coil  55 , and armature  75 . When no power is provided to coil  55 , armature  75  comprising seal  75   b  is biased towards body  73  by way of spring  77  thereby sealing opening  73   a , in body  73 . When coil  55  is energized, armature  75  is directed away from opening  73   a  allowing hydrogen fuel to pass through. Quick connect valve  71  is located downstream of solenoid valve  70  and is actuated by the insertion of projection  56  of connector  54 . Quick connect valve  71  comprises piston  81 , fitting body  83 , and o-ring seal  85 . When container  8  is not coupled to connector  54 , spring  87  biases piston  81  to a stop such that it engages o-ring  85  thereby sealing opening  58 . However, when container  8  is coupled to connector  54 , piston  81  is displaced away from o-ring seal  85  by projection  56  such that is clears chamber  91 . This allows for the flow of fuel from opening  73   a , through holes  95  into chamber  91 , and then out through opening  58 . Fuel therefore cannot escape from container  8  without the simultaneous actuation of both solenoid valve  70  and quick connect valve  71 . 
     As with the embodiment shown in FIGS. 1-5, the outside face presented by fitting  92  is essentially flat and is thus relatively easy to keep free of debris. Electrical connections are made to solenoid coil  55  in a similar manner. In FIGS. 6 a  to  c , an electrical connection is made to annular conductor  55  which is insulated from fitting body  83  by insulator  93  and is connected to coil  55  by way of a wire (not shown). Coil  55  is grounded through metal fitting body  83  and container  8 . Preferably, a sintered filter (not shown) is also employed at the inside surface of fitting  92 . 
     With reference to FIG. 7, a system whereby one or more pressurized gas containers  8  are coupled to a gas intake manifold  52  is shown. FIG. 7 is a diagrammatical illustration and the parts corresponding with the parts shown in FIGS. 6 a, b , and  c  are given like reference numerals. The manifold  52  has a support rail which is indicated by reference numeral  60 . Reference numeral  62  indicates one-way (check) valves which are built into the manifold  52  to prevent the backflow of gas. 
     Four containers  8  are shown connected by quick connectors  50  to the manifold rail  60 . Each container  8  has a fitting containing a solenoid valve  70  described above with reference to FIG. 6 c . In the present example, the valve coil or solenoid  55  has a resistance of 70 Ω. 
     As shown, +12 V is applied to the system through a fuse  72 . A control relay  74  is provided for each quick connector  50 . The circuit includes a relay  76  which closes when a hydrogen gas leak is sensed by a hydrogen gas sensor (not shown) and a thermoswitch  78  which closes when a high enclosure temperature is sensed. If either one of the relay  76  or thermoswitch  78  closes, a high current flows through to ground which blows the fuse  72 , thereby shutting off electrical power. This results in all the valves  70  automatically closing. 
     The presence or absence of a container  8  at each position on rail  60  may be detected using a simple sensing circuit. This information may then be used by a control system to estimate how much hydrogen is available for power generation (by number of containers present) and whether or not to energize a particular control relay  74 . For instance, a simple sensing circuit is illustrated at one position on rail  60  in FIG.  7 . In sensing circuit  79 , a +5 V supply is connected via resistor  80  to the downstream side of control relay  74 . Sense wire  82  is also connected to the downstream side of control relay  74 . Resistor  80  is selected such that it has a much greater resistance than solenoid valve coil  55  (for instance, resistor  80  is 10 kΩ and coil  55  is about 70 Ω). Before energizing any solenoid valves  50 , +5 V will be detected by the sense wire if a container is absent. However, if a container is present, the +5 V supply voltage will drop mainly across resistor  80  and sense wire  82  will detect close to zero volts instead. 
     While only preferred embodiments of the invention have been described herein in detail, the invention is not limited thereby and modifications can be made within the scope of the attached claims.