Abstract:
Disclosed herein is multiple filter controller comprising two filters; an inlet valve that regulates the directional inflow of a fluid through the filters; and an outlet valve that regulates the directional outflow of the fluid from the filters. Further disclosed is a method for maintaining a working fuel system comprising: passing the fuel through a first filter; monitoring an amount of pressure as the fuel passes through the first filter; detecting when the pressure has reached a predetermined level; redirecting the fuel from the first filter to a second filter when the predetermined level has been detected by manipulating an inlet valve such that the inlet valve stops the flow of the fluid to the first filter and redirects the flow of the fluid to a second filter; and repairing or removing the first filter from the fuel system while the fuel is simultaneously flowing through the second filter.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
   This application claims the benefit of U.S. Provisional Application No. 60/556,285 filed on Mar. 26, 2004. 

   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The invention relates generally to a multiple filter controller and to a system incorporating the multiple filter controller. More specifically, the invention relates to a multiple filter controller, wherein the multiple filter controller comprises at least two filters in-line with a common inlet valve, a common outlet valve, and a throughput system, wherein the multiple filter controller can detect a faulty filter and can alert an operator of the need to repair or replace the faulty filter with a workable filter. 
   2. Background of the Invention 
   During normal use, filters often clog, restrict, tear, or otherwise undergo physical alterations such that the filters fail to optimally perform. Such alterations can create obvious problems whenever a system&#39;s successful operation depends on the continuous working performance of a filter. 
   Nowhere is the need for a filter&#39;s continuous optimal performance more evident than where a filter is responsible for the continued operation of an engine, such as an internal combustion engine. For example, fluids used in conjunction with an internal combustion engine, such as engine lubricating oil, transmission fluid, engine coolant, and engine fuel, often require continuous filtering so as to prevent contaminants in the fluid from depositing on and adversely affecting components of the engine and related systems. On internal combustion engines, which are operated continuously or near-continuously for long periods of time, such as diesel engines used to generate electrical power and diesel engines in trucks, trailers, recreational vehicles, and boats, the large quantity of fluid passing through the filter, in combination with partially contaminated fluids such as lower quality diesel fuel, result in operational difficulties and/or unexpected engine shut-downs due to premature filter plugging. 
   Referring to  FIG. 1 , a conventional diesel fuel system comprises a fuel tank  1  in-line with a primary filter  2 , wherein primary filter  2  is in-line with a fuel pump  3 . A secondary filter  4  connects fuel pump  3  with injector pump  5 , wherein injector pump  5  comprises injection nozzles that send the fuel from injector pump  5  into an engine. During normal use, fuel storage tank  1  collects dirt, water, varnishes, rust, and bacteria. The increased level of contaminants in tank  1  cause primary fuel filter  2  to clog at a much faster rate than if fuel storage tank  1  did not collect such debris. As the clog prevents the fuel from reaching the engine, the engine ultimately shuts down. However, prior to shutdown, engine driven fuel pump  3  will naturally increase its vacuum to draw more fuel across primary filter  2 . Because of this increase in vacuum, any loose hose clamps or poor connections will allow air to enter the fuel system, wherein such excess air reduces the overall efficiency of the system. 
   Accordingly, it is important to have a device comprising multiple filters capable of continuous operation such that a backup filter can quickly and easily replace a malfunctioning filter without the need to shut down the entire system. However, in many cases changing the malfunctioning filter can result in significant problems in priming and bleeding the system, which results in significant leakage of the fluid into the environment. Therefore, what is needed is a device comprising a backup filter that can be activated without the need to first remove or disassemble the now malfunctioning filter. 
   SUMMARY OF THE INVENTION 
   The problems discussed above are eliminated or greatly reduced by a multiple filter controller designed to allow a second in-line primary filter to be installed in a system that allows an operator to select it if the first primary in-line filter starts to clog or otherwise malfunction. A built in pressure gage and vacuum switch allow for easy monitoring of the in-line filter, and a remote annunciator panel can alert an operator if the filter is malfunctioning. This advance warning allows the multiple filter controller to make a simple task of switching to another in-line filter without a simultaneous shutdown of the engine. An operator can then deal with the malfunctioning filter, changing it if needed or draining the contaminants out of the offline filter. The multiple filter controller may also comprise a boost pump that enhances system bleeding and servicing. A fuel bleed port is incorporated into the multiple filter controller to allow filter servicing and system bleeding as needed. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is an illustration depicting a conventional fuel system; 
       FIG. 2  is an illustration depicting an exemplary multiple filter controller; 
       FIG. 3  is an illustration depicting exemplary electrical connections of an exemplary system comprising the multiple filter controller depicted in  FIG. 2 ; 
       FIG. 4  is an illustration depicting the multiple filter controller also shown in  FIG. 2 ; and 
       FIG. 5  is an illustration depicting an exemplary fuel system comprising an exemplary multiple filter controller. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Disclosed herein is a multiple filter controller comprising at least two filters, wherein the multiple filter controller is capable of detecting which filter(s) is no longer properly performing, and of switching operation from the malfunctioning filter(s) to a fresh, functioning filter(s). The multiple filter controller can either automatically exchange one or more malfunctioning filters with a replacement filter(s) and/or can alert an operator to the desirability of changing the malfunctioning filter(s), upon notification of which, an operator may manually redirect the flow of fluid from the malfunctioning filter(s) to a properly functioning filter(s). 
   In an exemplary embodiment, the multiple filter controller comprises a first filter in fluid communication with a fluid source, and a second filter in fluid communication with the same or a different fluid source. An inlet valve determines the directional inflow of the fluid through the multiple filter controller, such that the inlet valve directs the fluid to either the first filter and/or to the second filter. An outlet valve controls the directional outflow of fluid through the multiple filter controller, such that the outlet valve directs the fluid either from the first filter and/or from the second filter into the remaining portions of the multiple filter controller. Although the types of fluids which can be fed through the multiple filter controller can vary widely, and is ultimately dependent upon the specific application of the multiple filter controller, a preferred fluid comprises fuel, wherein diesel fuel is particularly preferred. 
   In an exemplary embodiment, the remaining portions of the multiple filter controller comprises a vacuum switch which can alert an operator if a filter is malfunctioning, as indicated by a build up of pressure within the multiple filter controller that exceeds a predetermined maximum pressure value. The multiple filter controller may also comprise a pressure gage, whereby an operator can readily visualize the pressure contained within the device at any desired moment. Once the pressure exceeds a predetermined level, or is under a predetermined level, the vacuum switch can electronically communicate with either a local annunciator and/or with a remote annunciator. The annunciator(s), by at least one of visual, auditory, or vibrational means, can alert an operator that a change of filters is recommended. Additionally or alternatively, the vacuum switch can trigger the inlet and outlet valves to automatically switch filters without the need for human interference. While the system of which the multiple filter controller forms a part continues to operate, the filters may be switched from the malfunctioning filter to a properly functioning filter in a safe manner whereby spillage of remnant fluids may be decreased. 
   It is contemplated herein that, although the present disclosure identifies only two filters in the multiple filter controller, any number of filters may be incorporated into the multiple filter controller in a manner that will be obvious to one of ordinary skill in the art after a full reading of the present disclosure. Additionally, the filters of the multiple filter controller may comprise a wide variety of filters, such as, for example, filters of a conventional, spin-on canister-type. Also, the present invention contemplates the use of any filter media with a finite life, or which is not regenerative. For example, the present invention includes cartridge filters. Additionally, each filter forming the multiple filter controller disclosed herein may comprise the same, similar, or different type of filter as the other filter(s) that is part of the multiple filter controller. 
   For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated multiple filter controller, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates. 
     FIG. 2  depicts an exemplary multiple filter controller  10 . Here, multiple filter controller  10  comprises an inlet pipe  11  that leads to a conduit  14  and to a conduit  18  via an inlet valve  20 . Conduit  14  leads to an inlet port  13  of a filter  12 , and conduit  18  leads to an inlet port  15  of a filter  16 . 
   Inlet valve  20 , either by automatic means or by manual means, can open or close conduits  14  and  18 , thereby governing which of filters  12  and  16  is to be utilized for a particular operation. That is, inlet valve  20  may be positioned to allow the fluid to exclusively enter either filter  12  or filter  16 . In an alternative embodiment, inlet valve  20  may be positioned to allow fluid to enter both filter  12  and filter  16 , such as when, for example, neither filters are working optimally, or, for example, to slowly wean filter  12  from use or during the inauguration of filter  16  into use. 
   Additionally, multiple filter controller  10  comprises a conduit  22  that connects an outlet port  17  of filter  12  to a manifold  24 . Similarly, multiple filter controller  10  comprises a conduit  26  that connects an outlet port  19  of filter  16  to manifold  24 . Manifold  24  comprises an outlet valve  28 , wherein outlet valve  28  is positioned to direct, either automatically or by manual means, the flow of fluid from at least one of conduits  22  and  26 . That is, outlet valve  28  may either open conduit  22  to allow the flow of fluid from filter  12  while simultaneously closing conduit  26  to prevent the flow of fluid from filter  16 , or outlet valve  28  may open conduit  26  to allow the flow of fluid from filter  16  while simultaneously closing conduit  22  to prevent the flow of fluid from filter  12 . Additionally, outlet valve  28  may allow access of the fluid out from both conduits  22  and  26 . It is noted that the term “fluids”, as used herein and throughout, may comprise any gaseous fluids or liquid fluids relevant to a particular use of the multiple filter controller. For example, where the multiple filter controller is to be used on a boat or on a recreational vehicle as part of the fuel system, an exemplary fluid comprises diesel fuel. 
   A conduit  30 , which conducts the fluid from conduits  22  and  26 , extends from manifold  24  to a manifold  32 . At manifold  32 , a conduit  34  is in communication with conduit  30 , wherein conduit  34  comprises conduits  34   a  and  34   b . Conduit  34   a  leads to a boost pump  36  and conduit  34   b  leads to a check valve  38 . At a manifold  40  a conduit  39  comprises a conduit  39   a  and a conduit  39   b , wherein conduit  39   a  is in communication with boost pump  36  and joins conduit  39   b , and wherein conduit  39   b  is in communication with check valve  38  and joins conduit  39   a . Boost pump  36  is preferably used to suction the fluid from its originating source, e.g., to suction fuel from a fuel tank, and feed the fuel through filters  12  and  16 . Additionally, boost pump  36  may be used to assist in bleeding multiple filter controller  10  when used in conjunction with a bleed valve  48 . Such bleeding is particularly desirable when, for example, an operator is replacing or fixing filter  12 . Check valve  38  serves to prevent the backflow of fluid. That is, once the fluid passes through check valve  38  and into conduit  39   b , check valve  38  prevents the fluid from flowing back through check valve  38  and into conduit  34 . 
   A conduit  41  branching into conduit  41   a  and conduit  41   b  is joined to conduit  39  at manifold  40 . A terminal end of conduit  41  is connected to a pressure gage  42 , wherein pressure gage  42  indicates the pressure contained in multiple filter controller  10 . Additionally, a vacuum switch  44 , which is in electrical communication with an annunciator (not shown), is engaged with conduit  41   a . Once the pressure contained in multiple filter controller  10  exceeds a predetermined pressure level, or is below a predetermined pressure level, vacuum switch  44  sends an electrical signal to the annunciators to alert an operator. Alternatively, or additionally, vacuum switch  44  or another electrical connector, may electrically signal inlet valve  20  and outlet valve  28  to reorient their respective positions such that the fluid no longer enters and exits the malfunctioning filter, but rather, enters and exits a properly functioning filter. 
   Conduit  41   b  extends upwardly to a manifold  46  where conduit  41   b  joins conduit  43 . Conduit  43  comprises conduits  43   a  and  43   b . In fluid communication with conduit  43   b  is bleed valve  48 , wherein bleed valve  48  allows excess air to be removed from multiple filter controller  10 . Conduit  43   a  terminates in an outlet  50 . 
   It is herein noted that either one of boost pump  36  and check valve  38  are optional. Accordingly, in an exemplary embodiment, a single conduit may extend from manifold  24  to manifold  40 , whereby the fluid simply moves through at least one of conduits  22  and  26  and feeds into the single conduit wherein the single conduit leads the fluid to conduit  41 . 
   Although  FIG. 2  depicts only two filters and the filters&#39; respective conduits which link the filters to outlet  50 , it is contemplated herein that the multiple filter controller may comprise more than two filters, wherein the number of filters is determined by the operational requirements of the multiple filter controller. Where additional filters are used, each filter can be connected to outlet  50  in a similar manner as has been previously described with reference to  FIG. 2 . However, additional conduits would be utilized to link the respective filter to the valves and manifolds depicted in  FIG. 2 . Also, valves  20  and  28  would be adapted to shut on and off access to any excess filters, i.e., filters that are not currently being utilized during the operation of the multiple filter controller. 
   Multiple filter controller  10  is preferably designed to allow fluids to flow through at least one filter and through the various conduits in-line with the respective filter(s). As the filter(s) that is being used during the operation of the multiple filter controller becomes faulty, such as, when the filter becomes clogged with debris, pressure begins to build-up within the multiple filter controller. Once the pressure reaches a preset magnitude, the multiple filter controller switches from the faulty filter(s) to a functional filter. The multiple filter controller can either automatically switch filters, or an operator can manually adjust valves  20  and  28  to close off the respective conduits of the faulty filter, and to open the conduits of the non-faulty filter. 
   For example, referring to  FIG. 2 , valves  20  and  28  may initially be set to allow a flow of fluid through filter  12 . Should filter  12  clog or otherwise be unable to allow sufficient passage of fluid through filter  12  into conduit  22 , pressure resulting from an external pump&#39;s force will either extend over a maximum preset threshold pressure or fall below a minimum preset threshold pressure, whereby vacuum switch  44  will signal to a local annunciator and/or a remote annunciator that filter  12  is in need of repair or replacement. The local annunciator is preferably disposed on a surface of a housing, wherein the housing contains the various conduits and valves of the multiple filter controller, and which is represented as a dashed line in  FIG. 2 . In an exemplary embodiment, the local annunciator may comprise a light indicator to indicate that boost pump  36  is on and another light indicator to indicate when the filter in use should ideally be changed. The remote annunciator, as described more fully below in reference to  FIG. 3 , may also comprise the above-described light indicators, but may be placed in a more convenient place of visibility to an operator, such as on the steering panel of a vehicle. Additionally, or alternatively, the local and remote annunciators may also comprise auditory indicators to perform the same function as the light indicators. 
   Once an operator is notified that the primary filter is in need of repair or replacement, the operator can switch valves  20  and  28  such that fluid can no longer pass through filter  12 , but rather the fluid passes through filter  16 . While filter  16  is operating, an operator can fix or replace filter  12 . 
   Still referring to  FIG. 2 , boost pump  36  may be used to suction fluid from its originating source and feed the fluid through filters  12  and  16 . Additionally, boost pump  36  may be used to assist in bleeding the multiple filter controller such as when, for example, either one or both of filters  12  and  16  is not operating. 
   As previously stated, an operator may be alerted to the pressure accumulation in the multiple filter controller by means of a remote annunciator in electrical communication with vacuum switch  44 . An exemplary electrical connection between the multiple filter controller and the remote annunciator, wherein the remote annunciator provides visual signals in the form of, for example, a green light when the system if functioning properly and, for example, a yellow light for when the system is not functioning property, is depicted in  FIG. 3 . Here, vacuum switch  44  of the multiple filter controller is in electrical communication with a fuel pump  84 , wherein fuel pump  84  is of the conventional type typically found in-line with, e.g., a diesel fuel filter system. Additionally, a switch  86 , a green light lamp  88 , a yellow light lamp  90 , a first connector  92 , and a second connector  94  are further electrically connected to vacuum switch  44  and to fuel pump  84 . When the accumulated pressure, as measured by the pressure gage (referenced by reference numeral  42  in  FIG. 2 , is within normal functioning limits, green light lamp  88  transmits an electric signal to first and second connectors  92  and  94 . Connectors  92  and  94  display the green light at a remote location, such as, for example, on the steering panel of a boat. When the accumulated pressure, however, reaches a predetermined amount indicative of a malfunction by one of the filters, green light lamp  88  is deactivated, and yellow light lamp  90  is activated, thereby sending an electric signal to first and second connectors  92  and  94  to display the yellow light at the remote location. 
   An exemplary housing for multiple filter controller is depicted in  FIG. 4 . Here, a housing  60  comprises an inlet  62  for filter  12  as shown in  FIG. 2  and an inlet  64  for filter  16  as shown in  FIG. 2 . Housing  60  further comprises an outlet  66  for filter  12  and an outlet  68  for filter  16 . Housing  60  further comprises a filter inlet selector  75 , which controls the positioning of inlet valve  20 , a filter outlet selector  77 , which controls the positioning of outlet valve  28  and pressure gage  42  as shown in  FIG. 2 . Bleed valve  48  is attached to conduit  43   b . Housing  60  further comprises an on/off switch  70  which can activate/deactivate boost pump  36  (not shown). Housing  60  also comprises annunciators comprising a check filter indicator  71  and an indicator that boost pump  36  (not shown) is on/off  73 . 
   An exemplary application of the multiple filter controller as disclosed herein is depicted in  FIG. 5 .  FIG. 5  depicts an exemplary fuel system comprising multiple filter controller  10  in-line downstream from a fuel tank  72 , and in-line upstream from a fuel pump  74 , a secondary filter  76 , and an injector pump  78 . In this embodiment, fuel pump  74  pumps fuel from fuel tank  72 , such that the fuel enters at least one of filters  12  and  16 . The fuel then enters the remainder of multiple filter controller  10  as disclosed above, exits multiple filter controller  10  through outlet  50 , and proceeds to flow through fuel pump  74 , secondary filter  76 , and fuel injector pump  78  via respective conduits  80  and  82 . 
   Although  FIG. 5  depicts a fuel tank  72 , depending on the use of the multiple filter controller, fuel tank  72  may instead comprise, for example, an engine oil sump, transmission sump, or other source of fluid used with an internal combustion engine. Similarly, fuel pump  74  may be an oil pump, transmission fluid pump, or other pump associated with an engine or vehicle system, the system being the receiver of the conditioned fluid. 
   In an exemplary application of fuel system  20 , valves  20  and  28  are positioned to allow the fuel to pass through filter  12 . Fuel pump  74  suctions the fuel from fuel tank  72  through filter  12 , whereby filter  12  serves to eliminate or greatly reduce the passing of contaminants from fuel tank  72  into injector pump  78 . Additionally, boost pump  36  in multiple filter controller  10  may be used to further pump the fuel through filter  12 . Should filter  12  become ineffective in controlling the level of contaminants that pass through fuel system  70 , pressure from fuel pump  74  and/or from boost pump  36  builds up within multiple filter controller  10 . Once the pressure exceeds a preset amount, an operator is notified to switch from filter  12  to filter  16 , or multiple filter controller  10  can automatically switch filters. An operator can read the pressure from pressure gage  42 . Filter  16  can replace filter  12  simply by adjusting the position of valves  20  and  28  such that the fuel now enters and exits filter  16 . While filter  16  is operating, an operator can replace filter  12 , or can repair filter  12  in-line. Additionally, multiple filter controller can be bled via bleed valve  48  while fuel system  70  is still in operation. Additionally, boost pump  36  can assist in the bleeding of multiple filter controller  10 . 
   Multiple filter controller  10  is particularly advantageous over other filter devices currently in existence, in that it allows a faulty filter to be replaced or repaired without the need to turn off the engine. An exemplary method for changing filter  12  utilizing multiple filter controller  10  comprises turning boost pump  36  on such that any air contained in, e.g., conduits  14 ,  22 ,  30 ,  34 ,  39 , and  41  can be released by means of bleed valve  48 . Inlet valve  20  and outlet valve  28  are positioned to redirect the passage of fluid from filter  12  to filter  16 . Once the fluid has moved through the system such that any excess air contained in multiple filter controller  10  has been released, boost pump  36  may be turned off, wherein the fluid can then move through the multiple filter controller to outlet  50  via check valve  38 . Boost pump  36 , then, allows for a sanitary method of removing the faulty filter. 
   Where multiple filter controller  10  does not comprise boost pump  36 , the fluid can still be pumped through multiple filter controller  10  by means of a pump either upstream or downstream of device  10 . Additionally, multiple filter controller  10  can still be bled by means of bleed valve  48 . However, the use of a boost pump  36  enhances the efficiency of bleeding. Valve  28  also assists in the sanitary and safe removal of the faulty filter, in that it reduces the amount of fluid remaining in the filter&#39;s respective conduits such that when the filter is removed, less fluid spills out of the multiple filter controller. That is, the faulty filter may be removed with the engine running without gross leakage, loss of fluid priming in the engine system, or ingestion of air into the engine system. 
   Additionally, the applications of the multiple filter controller as disclosed herein are varied, and include any system wherein back-up filters are desired. Such systems may comprise for example, trailers, campers, and marine engine systems. 
   The benefits of the multiple filter controller as disclosed herein are many. For example, the multiple filter controller provides a reliable back-up support for a system dependent upon the use of a filter. Additionally, the multiple filter controller can continue operating the system while an operator replaces or fixes a faulty filter. Also, the multiple filter controller provides a simplified means whereby multiple filters can be attached to an outlet conduit. The multiple filter controller further comprises a mechanism whereby the device can be bled during operation of the system. Accordingly, a faulty filter can be repaired or removed without undue leakage of fluid. 
   It is further intended that any other embodiments of the present invention that result from any changes in application or method of use or operation, method of manufacture, shape, size, or fluid which are not specified within the detailed written description or illustrations contained herein, yet are considered apparent or obvious to one skilled in the art, are within the scope of the present invention.