Abstract:
Disclosed is an apparatus for providing in-line, three-state, dual flow metering, high pressure relief, for use in a system utilizing compressible or incompressible media, which includes a centrally disposed magnetically homed ball with opposing axially aligned ball mating valve seats, with a high pressure relief spring deployed to control the pressure necessary to trigger high pressure relief.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application relates to and claims the benefit of two provisional applications filed on Nov. 14, 2008, and having application Nos. 61/199,217 and 61/199,219 and entitled “PNEUMATIC DAMPER” and “FLUID CONTROL VALVE” respectively, by the same inventors. These provisional applications are incorporated herein in their entirety by this reference. This application also relates to an application entitled “PNEUMATIC DAMPER” by the same inventors which is filed on even date herewith. This application is also incorporated herein in its entirety by this reference. 
    
    
     TECHNICAL FIELD OF THE INVENTION 
     The field of technology for this invention is the broad area of fluid control. The invention provides a multifunctional apparatus which allows bi-directional flow to be controlled, using a three-state configuration. 
     BACKGROUND 
     Air seat suspension systems are expected to respond to relatively high amounts of often sudden and sometimes erratic forces. The needs of the system frequently change, depending upon key variables, such as driver weight and the vehicle load. The environmental conditions inside a cab of a parked vehicle can vary dramatically over a short time, with temperature changes of 100 degrees F. in under an hour. Some prior art systems are too costly for widespread deployment. 
     Consequently, there is a need for a low cost, rugged, adjustable, three-state, bi-directional flow control device. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide an economical rugged, adjustable, three-state, bi-directional flow control device. 
     It is a feature of the present invention to include a magnetically homed ball with adjustable magnetic forces. 
     It is an advantage of the present invention to allow a simple screw adjustment to make changes in the system setting. 
     It is a feature of the present invention to include an electro-magnetically homed ball, with real time electronic control of the system. 
     It is another advantage of the present invention to provide the system with real time electronic control. 
     It is another feature of the present invention to include interchangeable orifices and springs. 
     It is another advantage of the present invention to allow for relatively easy reconfiguration of internal system parameters. 
     The present invention is designed to achieve the above object, contain the previously mentioned features and enjoy the stated advantages. 
     Accordingly, the present invention is:
         a valve comprising:   a substantially cylindrical valve body comprising a central fluid channel having a plurality of internal sections with each of said plurality of internal sections having a different diameter dimension;   a substantially spherical flow stopper;   a first piston configured to slide in said central fluid channel and sized to create an airflow permitting gap between said first piston and said valve body;   said first piston comprising:   a member with a central void and a seat configured to at least partially mate with said spherical flow stopper;   a port extending through said first piston and coupling said airflow permitting gap with the central void in said member;   a first spring disposed in said valve body to resist movement of said first piston along said central fluid channel;   a first pressure relief channel disposed in said valve body which is configured to provide a passage for airflow only when said first piston has compressed said first spring by a first predetermined distance;   wherein said first piston further comprises:
           a ball mating section having a first diameter;   a first displacement resistance mating section having a second diameter which is larger than said first diameter;   an “O” ring seal disposed around said ball mating section adjacent to said first displacement resistance mating section, configured to prevent airflow except when said first piston has compressed said spring by said first predetermined distance; and   a magnet disposed in said valve body configured for retaining said spherical flow stopper in a predetermined location in the absence of airflow around said spherical flow stopper.   
               

    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an end view of a single ball and single spring valve assembly of the present invention. 
         FIG. 2  is a cross-sectional view of the single ball and single spring valve assembly taken on line A-A of  FIG. 1 , where the internal components are at State I. 
         FIG. 3  is an enlarged detailed view of the single ball and single spring valve assembly taken inside detail Circle B of  FIG. 2 . 
         FIG. 4  is a cross-sectional view of the single ball and single spring valve assembly taken on line A-A of  FIG. 1 , where the internal components are at State III. 
         FIG. 5  is a cross-sectional view of the single ball and single spring valve assembly taken on line A-A of  FIG. 1 , where the internal components are at State II. 
         FIG. 6  is a cross-sectional view of the single ball and single spring valve assembly taken on line A-A of  FIG. 1 , where the internal components are at State II with activated pressure relief. 
         FIG. 7  is an end view of the single ball and double spring valve assembly of the present invention. 
         FIG. 8  is a cross-sectional view of the single ball and double spring valve assembly taken on line A-A of  FIG. 7 , where the internal components are at State I. 
         FIG. 9  is an end view of a double ball and single spring valve assembly of the present invention. 
         FIG. 10  is a cross-sectional view of the double ball and single spring valve assembly taken on line A-A of  FIG. 9 , where the internal components are at State I. 
     
    
    
     DETAILED DESCRIPTION 
     The invention is applicable for both compressible and incompressible fluid media; however, this disclosure pertains to the device being used within a compressed air circuit. In a particular application, the invention bodes well as a design solution for use in a seat suspension system. 
     Now referring to the drawings wherein like numerals refer to like matter throughout and more specifically referring to  FIGS. 1 ,  2  and  3 , there is shown the valve assembly generally designated  1  of the present invention, which contains a valve body  2  with a cylindrical communication passage  3  of a predetermined diameter and length, which ultimately connects port A  20  of the valve assembly  1  with port B  21  of the valve assembly  1 . Valve body  2  contains a central fluid channel with a plurality of internal sections with variable width characteristics or diameter dimension which corresponds to a variable width characteristic of communication passage  3 . 
     Located within the communication passage  3  is a flow seal device, ball or spherical flow stopper  10  which may be of a controlled spherical dimension and is smaller than the thinnest portion of the communication passage  3 . Located at a position tangential to the flow seal device or ball  10  and within the valve body  2  is a magnet  11  for retaining the flow seal device  10  on the predetermined location. The magnet  11  is located via a magnet adjustment screw  12  such that the holding strength of the magnet  11  on the flow seal device  10  can be varied. The magnet  11  serves to retain the flow seal device  10  on location during events of minimal airflow State I described below. Additionally, the magnet  11  serves to “home”, or return, the flow seal device  10  back to the initial location after having been unseated due to airflow characteristics described below as State II and State III, respectively. This action of the magnet  11  assists the flow seal device  10  from simply pinging between the flow seal device seats  5  and  8 , also later discussed. This process supports the operation of the valve assembly  1  to more quickly achieve steady-state airflow characteristics. 
     Located on the port A  20  side of the valve assembly  1  is fitting  7 , which ultimately connects the communication tubing  13  with the communication passage  3 . Fitting  7  has a wrench mating surface  70  thereon to assist in the insertion of fitting  7  into valve body  2 . Located immediate to fitting  7  opposite the communication tubing  13  is piston  16  which embodies a member with a central void, flow seal device seat  8 , orifice or port  9  and piston seal  17 . 
     Located on the port B  21  side of the valve assembly  1  is fitting  4 , which ultimately connects the communication tubing  13  with the communication passage  3 . Located immediate to fitting  4  opposite the communication tubing  13  is an internal pressure regulating spring  14  and piston  18  which embodies flow seal device seat or piston seat  5 , orifice  6  and piston seal  19 . Note that the figures show piston  18  touching the inside wall of communication passage  3 ; it should be understood that a gap or airflow permitting gap of a predetermined dimension could exist between the piston  18  and the communication passage  3 , especially between the seat  5  and the wall of the communication passage  3 . This will enable a certain amount of airflow to occur. 
     A method to carry out the invention is herein described. The functionality of the invention is best described by three independent states. 
     State I. Steady-State Airflow Between A to B 
       FIGS. 2 ,  3 ,  8  and  10   
     When airflow is freely communicated between port A  20  and port B  21  with a minimal pressure drop across the flow seal device  10 , the magnet  11  retains the flow seal device  10  on location and promotes full flow between port A  20  and port B  21 . The flow seal device  10  remains on location of the magnet  11  until the time instant when a pressure and flow gradient across the flow seal device  10  is developed which becomes increasingly large enough to overcome the holding strength of the magnet  11 , causing the flow seal device  10  to move within the communication passage  3  toward either flow seal device seat A  8  discussed below with respect to  FIG. 4  and State III or flow seal device seat B  5  discussed below with respect to  FIG. 5  and State II. In the Steady State, State I, the airflow characteristics within the valve assembly  1  are controlled by the effective orifice area created due to the diametrical differences of flow seal device  10  and the communication passage  3 . 
     State II. High Pressure Airflow from A to B 
     Now also referring to  FIG. 5 , when airflow is moving in the direction from port A  20  toward port B  21  with sufficient flow and pressure to overcome the holding strength of the magnet  11 , the flow seal device  10  becomes seated against the flow seal device seat B  5  of piston B  18 . When the flow seal device  10  becomes fully seated within flow seal device seat B  5 , the airflow is primarily restricted to flowing between the flow seal device seat B  5  and the wall in valve body  2  defining communication passage  3  and then through the orifice B  6  as the piston seal B  19  prohibits further airflow around the piston B  18 . Note: depending upon the predetermined goodness of the seal between seat  5  and ball  10 , some air may be permitted to flow directly into the central void  51 . The restricted air flows through orifice B  6  into central void  51  and fitting B  4  into the communication tubing  13  at port B  21 . In this state, the directional airflow characteristics are controlled by the effective orifice area of the orifice B  6 , thus controlling the degree of pressure developed within the port A  20  side of the valve assembly  1 . Furthermore, in this state, and now referring to  FIG. 6 , if the air pressure developed due to the airflow restriction is great enough to overcome the force of the internal pressure regulating spring  14  acting on piston B  18 , piston B  18  will travel in the direction toward fitting B  4  until piston seal B  19  travels beyond the opening of internal pressure regulating channel or pressure relief channel  15 . Internal pressure regulating channel  15  is a keyway-type slot in the valve body  2 . At this instant, the generated air pressure immediately releases past piston seal B  19 , flowing into the larger cavity created by the internal pressure regulating spring  14  and internal pressure regulating channel  15  and through fitting B  4  and communication tubing  13  located at port B  21 . This immediate airflow maintains until the generated air pressure decreases to the state, whereby the force of the internal pressure regulating spring  14  acting on piston B  19  is now greater than the air pressure. 
     State III. High Pressure Airflow from B to A 
     Now also referring to  FIGS. 1 ,  3  and  4 , when airflow is moving in the direction from port B  21  toward port A  20  with sufficient flow and pressure to overcome the holding strength of the magnet  11 , the flow seal device  10  becomes seated against the flow seal device seat A  8  of piston A  16 . When the flow seal device  10  becomes fully seated within flow seal device seat A  8 , the airflow is restricted to flowing through the orifice A  9  as the piston seal A  17  prohibits airflow around the piston A  16 . The restricted air flows through orifice A  9  and fitting A  7  into the communication tubing  13  at port A  20 . In this state, the directional airflow characteristics are controlled by the effective orifice area of the orifice A  9 , thus controlling the degree of pressure developed within the port B  21  side of the valve assembly  1 . 
     Other embodiments of the invention exist with variations such as with a dual direction flow pressure relief component. This can be carried out without losing the intent of this invention by incorporating either a single or multiple internal pressure regulating spring(s)  14 , respectively. See  FIGS. 8 and 10 . 
     After studying the invention, it will become evident that the design allows flexibility for a specific application. State I can be controlled by changing the effective orifice areas between the flow seal device  10  and communication passage  3  changing the size and geometry of flow seal device  10 , as well as the length for which the flow seal device  10  must travel. Additionally, the holding strength of the magnet  11  can be set to allow a weaker or stronger release of the flow seal device  10 . Furthermore, the magnet  10  can be replaced with an electromagnet allowing further flexibility and control, including real time electronic control, to be induced into the invention. It also recognized that the airflow and pressure response within the valve assembly  1  is a primary function of the corresponding changes in the in-line streaming airflow characteristics and can be used to provide intelligence for an electronic controller. The intelligence could be used for communication with the electromagnet, as well as other controllable parameters to provide enhanced control over the valve assembly  1  system response. 
     States II and III can be independently controlled by changing the airflow restrictions developed by orifice A  9  and orifice B  6 . Interchangeable sleeves used in such orifices could be preferred in some embodiments. Furthermore, the goodness of seat between the flow seal device  10  and the flow seal device seat A  8  or flow seal device seat B  5 , respectively, govern airflow characteristics. 
     The quality of the seat between the flow seal device  10  and the flow seal device seat A  8  or flow seal device seat B  5  can also be governed by the geometry of the flow seal device  10 . Furthermore, the geometry can also promote the ability to more easily bias the flow seal device  10  toward either flow seal device seat A  8  or flow seal device seat B  5 , especially when incorporating an electromagnet control line  121  and electromagnet controls  120  of  FIG. 3  into the design. Note electromagnets could be used for magnet  11 , as well as other places in the valve body  2  and even in the seats  5  and  8 . Additionally, the flow seal device  10  geometry can be such that the flow seal device  10  may include a flow seal device core  110  that is either magnetic or non-magnetic. By using a flow seal device core, additional control and goodness of seat can be achieved. Furthermore, an alternate material for the flow seal device  10  or the flow seal device exterior  112  may be of a softer material than the seat to gain additional positive seating characteristics, such as that commonly found in industrial valve and valve seats. 
     The materials and processes used within the invention are standard to the industry relating to fluid control valves. For example, the valve body  2  may be machined from brass or plastic, or injection molded from plastic. Likewise, the piston A  16  and piston B  18  can be machined from brass or plastic, or injection molded. If manufactured from metal, brass is attractive for many reasons; i.e., relatively low cost, ease of machining, etc.; however, other metals and composite materials could be equally suitable. 
     It is also recognized that embodiments exist where the invention can be incorporated with other fluid control components, such as that of a height control valve commonly found within suspension systems used for cabs, chassis, etc. 
     Now referring to  FIG. 7 , there is shown an end view of the valve  100  of the present invention with valve body  200 . Valve body  200  may be identical in outer appearance and similar in construction to valve body  2 . 
     Now referring to  FIG. 8 , there is shown valve assembly  100  taken on line A-A of  FIG. 7 , which shows the ball in State I and shows dual internal pressure regulating spring(s)  14 , where each spring and piston function similar to that shown and discussed above with respect to  FIG. 6 . 
     Now referring to  FIG. 9 , there is shown an end view of a valve assembly  1000  of the present invention with a valve body  2000 . 
     Now referring to  FIG. 10 , there is shown the valve  1000  taken on line A-A of  FIG. 9 ; valve  1000  includes dual balls  10  and a common central internal pressure relief spring  14 . 
     It is thought that the method and apparatus of the present invention will be understood from the foregoing description and that it will be apparent that various changes may be made in the form, construct steps, and arrangement of the parts and steps thereof, without departing from the spirit and scope of the invention or sacrificing all of their material advantages. The form herein described is merely a preferred exemplary embodiment thereof.