Abstract:
A railroad train is provided and includes a first locomotive having a first locomotive electronic processor, a first locomotive communication device in electrical communication with the first locomotive processor, and a first locomotive operator interface in electrical communication with the first locomotive processor. The railroad train also includes a second locomotive having a second locomotive electronic processor, a second locomotive communication device in electrical communication with the second locomotive processor and the first locomotive communication device, a second locomotive sensor in electrical communication with the second locomotive processor for monitoring the operation of the second locomotive and generating signals indicative of the monitored operations, and a second locomotive controller device in electrical communication with the second locomotive processor for controlling the operation of the second locomotive, with the second locomotive processor receiving the signals indicative of the operation of the second locomotive, determining faults in the operation of the second locomotive, and communicating signals indicative of the faults to the second locomotive communication device for transmission to the first locomotive operator interface via the first locomotive communication device and the first locomotive processor, and with the second locomotive controller device being controllable from the first locomotive interface, wherein faults in the operation of the second locomotive are communicated to the first locomotive operator interface and control actions on the operation of the second locomotive in response to the faults may be effected by an operator on the first locomotive.

Description:
RELATED APPLICATIONS  
       [0001]     This application claims priority of U.S. Provisional Patent Application Ser. No. 60/590,555 filed Jul. 23, 2004, the contents of which are incorporated herein by reference in its entirety. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The present invention relates generally to communications between locomotives and, more particularly, to communication between locomotives in a consist operating in extreme environmental conditions.  
       BACKGROUND OF THE INVENTION  
       [0003]     Locomotives that are used for heavy haul applications tend to experience extreme environmental conditions, including low/high temperatures and/or high altitudes. In some situations, many locomotives are typically connected together to be able to pull heavy trains. These locomotives are interconnected electrically by MU trainlines so that an operator in the front locomotive can control the operation of the trailing locomotives. For example, freight trains are often hauled by multiple locomotive ensembles (“consists”) placed together at the front or rear of the train or dispersed among the freight cars. A single crew at the front of the train coordinates all of the locomotive throttles and brake commands via a connection called the multiple unit line (“MU-line”) that runs among the locomotives. Another example is, if the front, or lead, locomotive is in dynamic braking operation at a specified brake level (controlled by an operator request), then all of the locomotives in the consist are also operating in dynamic braking operation at the same specified level. As such, it should be appreciated that there may be multiple consists in a train and that these consists may be set up such that all of the locomotives in each consist act in unison.  
         [0004]     In addition to this kind of information, trainline modems (and other communication systems, like RF) are used to send other types of information regarding the operation of the trailing locomotives to the front locomotive (where the operator is typically located), including, but not limited to, operating mode, tractive/braking effort, horsepower, engine speed, motoring/braking failure, engine failure, battery charger failure and locked axle failure. Referring to  FIG. 1 , one example of a locomotive consist screen display  100 , in accordance with the prior art, is shown and may include several indications of fault occurrences. Currently, when an operator receives a fault occurrence indication, he/she has to travel back to the trailing locomotives to obtain further information regarding the fault, such as the fault code and/or the fault data, or at this point he/she can reset the fault, retry or reconfigure the locomotive (for example, cut out a traction motor).  
         [0005]     One disadvantage to this configuration is that when these locomotives are operating at higher altitudes it is difficult, and in some cases dangerous, for the operator to get down from the leading, or front, locomotive and get on a trailing locomotive, since only the operator cab in the front locomotive is provided with an oxygen supply and the locomotives may be covered in snow and/or ice. One possible way to address this problem might be to have the operator carry a portable oxygen tank when he/she is traveling between locomotives. Unfortunately however, these tanks can be cumbersome and heavy and in some situations, carrying these tanks can increase the likely hood of injury and/or death due to a potential buildup of ice and/or snow. Another disadvantage involves stopping the train at higher altitudes. Since it is not advisable to travel between the locomotives while the train is moving, in most cases the train must be stopped and since travel at higher altitudes typically includes traversing steep grades which may have snow and ice on the tracks, restarting the train tends to be difficult and may cause delays along the railroad line. Still another disadvantage with traveling between locomotives while the train is moving involves the operational disadvantage of the operator not being able to watch the track. As such, if there was debris, such as snow, rocks and/or trees or if there were an animal on the track, the operator would be unable to react and thus, would not be able to respond or even be aware of a dangerous situation until it is too late. Moreover, there may be other terrains, such as tunnels and very steep grades, and climate conditions, such as sub-zero temperatures and storms, where traveling between locomotives is not desirable, especially if the locomotive units are spaced a large distance apart from each other.  
       SUMMARY OF THE INVENTION  
       [0006]     A railroad train is provided, wherein the railroad train includes a first locomotive having a first locomotive electronic processor, a first locomotive communication device in electrical communication with the first locomotive processor, and a first locomotive operator interface in electrical communication with the first locomotive processor. The railroad train also includes a second locomotive having a second locomotive electronic processor, a second locomotive communication device in electrical communication with the second locomotive processor and in communication with the first locomotive communication device, a second locomotive sensor in electrical communication with the second locomotive processor for monitoring operation of the second locomotive and generating signals indicative of the monitored operations, and a second locomotive controller device in electrical communication with the second locomotive processor for controlling the operation of the second locomotive, with the second locomotive processor receiving the signals indicative of the operation of the second locomotive, determining faults in the operation of the second locomotive, and communicating signals indicative of the faults to the second locomotive communication device for transmission to the first locomotive operator interface via the first locomotive communication device and the first locomotive processor, and with the second locomotive controller device being controllable from the first locomotive interface via the first and second locomotive processors and the first and second locomotive communication devices, wherein faults in the operation of the second locomotive are communicated to the first locomotive operator interface and control actions on the operation of the second locomotive in response to the faults may be effected by an operator on the first locomotive.  
         [0007]     A communication/control system for a railroad train having a first locomotive and a second locomotive is provided and includes a first locomotive electronic processor, a first locomotive communication device in electrical communication with the first locomotive processor, and a first locomotive operator interface in electrical communication with the first locomotive processor. The communication/control system also includes a second locomotive electronic processor, a second locomotive communication device in electrical communication with the second locomotive processor and in communication with the first locomotive communication device, a second locomotive sensor in electrical communication with the second locomotive processor for monitoring operation of the second locomotive and generating signals indicative of the monitored operations, and a second locomotive controller device in electrical communication with the second locomotive processor for controlling the operation of the second locomotive, with the second locomotive processor receiving the signals indicative of the operation of the second locomotive, determining faults in the operation of the second locomotive, and communicating signals indicative of the faults to the second locomotive communication device for transmission to the first locomotive operator interface via the first locomotive communication device and the first locomotive processor, and with the second locomotive controller device being controllable from the first locomotive interface via the first and second locomotive processors and the first and second locomotive communication devices, wherein faults in the operation of the second locomotive are communicated to the first locomotive operator interface and control actions on the operation of the second locomotive in response to the faults may be effected by an operator on the first locomotive.  
         [0008]     A method for ensuring control of a locomotive within a locomotive consist, wherein the locomotive consist includes a first locomotive processor, a second locomotive processor and a second locomotive controller device communicated with the second locomotive processor, wherein the first locomotive processor is communicated with the second locomotive processor and wherein the second locomotive processor is configurable to allow the first locomotive processor to control the second locomotive controller device is provided, wherein the method includes monitoring the second locomotive controller device to determine whether a fault condition of the second locomotive controller device has occurred and if a fault condition has occurred, communicating the fault condition to an operator of the locomotive consist and operating the first locomotive processor to control the second locomotive controller device.  
     
    
     BRIEF DESCRIPTION OF THE FIGURES  
       [0009]     The foregoing and other features and advantages of the present invention will be more fully understood from the following detailed description of illustrative embodiments, taken in conjunction with the accompanying drawings in which like elements are numbered alike in the several Figures:  
         [0010]      FIG. 1  is a screen capture of a Consist Monitor Screen, in accordance with the prior art;  
         [0011]      FIG. 2  is a block diagram showing a first embodiment of a communication connection between locomotives in a locomotive consist;  
         [0012]      FIG. 3  is a screen capture of a Consist Monitor Screen for the locomotive consist of  FIG. 2 ;  
         [0013]      FIG. 4  is a block diagram showing a second embodiment of a communication connection between locomotives in the locomotive consist of  FIG. 2 ;  
         [0014]      FIG. 5  is a screen capture of a Consist Monitor Screen for the locomotive consist of  FIG. 4 ;  
         [0015]      FIG. 6  is a block diagram showing a third embodiment of a communication connection between locomotives in a locomotive consist;  
         [0016]      FIG. 7  is a screen capture of a Consist Monitor Screen for the locomotive consist of  FIG. 6 ; and  
         [0017]      FIG. 8  is a block diagram illustrating a method for ensuring control of a locomotive within a locomotive consist.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0018]     Referring to  FIG. 2 , a schematic block diagram illustrating one embodiment of a locomotive consist system  200  is shown and includes a first locomotive  202 , a second locomotive  204 , a third locomotive  206  and a fourth locomotive  208  connected in a consist  210  via a plurality of connection devices, such as a plurality of mechanical connection devices  212 . Additionally, each of the first locomotive  202 , the second locomotive  204 , the third locomotive  206  and the fourth locomotive  208  are communicated with each other via a Multiple Unit (MU) line  214 . Each locomotive may include a processing device  216 , an input/output device  218 , at least one controller device  220  and at least one sensing device  222 , wherein the processing device  216 , the input/output device  218 , the at least one controller device  220  and the at least one sensing device  222  may be communicated with each other. Moreover, the processing device  216 , the input/output device  218  and the at least one controller device  220  on each of the locomotives  202 ,  204 ,  206 ,  208  are further communicated with the remaining locomotives  202 ,  204 ,  206 ,  208  via the MU line  214  such that the processing device  216 , the input/output device  218 , the at least one controller device  220  and the at least one sensor device  222  on at least one of the locomotives  202 ,  204 ,  206 ,  208  is capable of establishing communication with the processing device  216 , the input/output device  218 , the at least one controller device  220  and the at least one sensor device  222  on at least one of the other locomotives  202 ,  204 ,  206 ,  208 . It should be appreciated that although the MU Line  214  is shown as being a hardwired connection, the MU Line  214  may utilize a wireless communications link, such as I/R, RF and Satellite.  
         [0019]     In the configuration shown in  FIG. 2 , as the consist  210  is operating, sensor data is being generated by the at least one sensor device  222  on each of the locomotives  204 ,  206 ,  208  and the generated data from the second locomotive  204 , the third locomotive  206  and the fourth locomotive  208  is being communicated to the first locomotive  202  via the MU line  214 , wherein the data may be displayed on the input/output device  218  of the first locomotive  202  to an operator. Referring to  FIG. 3 , one embodiment of a sensor display  300  on the input/output device  218  is shown and may include a Touch Menu Item (TMI) (softkey) screen  302  and/or a keyboard for command and/or data entry from the operator. The TMI screen  302  may include a plurality of software configurable input devices  303  such as a Network Restart switch  304  which is a request that the network information be resent to the sensor display  300 , a Fault Data switch  306  which is a request that all or some of the data that was generated at the time of the failure, which may or may not include fault data, be sent to the sensor display  300 , a Reset switch  308  which is a request to reset the faulted equipment, an Isolation switch  310  which is a request to isolate the faulted equipment and/or locomotive from the rest of the system, a Cutout switch  314  which is a request to cutout the faulted equipment from the rest of the system, an Order Modification switch  316  and an Exit switch  318 .  
         [0020]     Upon a condition that requires attention from the locomotive operator, such as a fault condition, an indication will be communicated to the operator that tells the operator that a condition has occurred that needs his/her attention and a condition indicator, which may be specific and/or general, will be displayed on the input/output device  218 , wherein the condition indicator may be in the form of a plurality of software configurable display indicators  320  and switches, which may be specific and/or general. It should be appreciated that the plurality of software configurable display indicators  320  may include, but not be limited to, a No Motor indicator  322 , a No DB (Dynamic Braking) indicator  324 , a No Batt indicator  326 , an Alarm Bell indicator  328 , an alternator regulator fault indicator  330  and a TM Ground Fault indicator  332 . Additionally, the plurality of software configurable display indicators  320  may also include a plurality of configurable operational performance indicators  334 , such as fuel level  336 , operational mode  338 , Oil Temperature  340 , traction HP  342 , Effort  344 , number of active axles  346  and Engine RPM  348 .  
         [0021]     This should allow the locomotive consist system  200  to inform the operator of a active fault or problem and a suggested course of action (from a stored databank and/or from personnel at a remote facility) and/or the operator may access a fault data display to link directly with and/or to obtain help from central service personnel. If the operator requires more information about the condition, he/she may operate the input/output device  218  to obtain more data which may be transmitted via the MU line  214  to the processing device  216 . Once the operator has obtained the desired information regarding the fault indication, the operator may send commands to the trailing locomotive(s), i.e. the second locomotive  204 , third locomotive  206  and/or the fourth locomotive  208 , responsive to the indicated fault condition. These commands may include, but may not be limited to, a fault reset command, a fault reevaluation command, a reconfiguration command to reconfigure the locomotives (individually or together) and a fault data display command. This would allow an operator in the lead locomotive to obtain critical/non-critical information and to control the operation of the remaining locomotives  202 ,  204 ,  206 ,  208  within the consist  210 .  
         [0022]     It should be appreciated that the following scenarios are only meant to illustrate the invention and thus are not meant to limit this invention to only these scenarios. As such, this invention is intended to be applicable to any scenario that may require action by the operator of the train. Referring to  FIG. 4 , consider the situation where there are four (4) locomotives operating in a locomotive consist system  400 . A schematic block diagram illustrating the locomotive consist system  400  is shown and includes a first locomotive  402 , a second locomotive  404 , a third locomotive  406  and a fourth locomotive  408  connected in a consist  410  via a plurality of connection devices, such as a plurality of mechanical connection devices  412 . Additionally, each of the first locomotive  402 , the second locomotive  404 , the third locomotive  406  and the fourth locomotive  408  may be communicated with each other via a Multiple Unit (MU) line  414 . As shown, each of the locomotives  402 ,  404 ,  406 ,  408  may include a processing device  416 , an input/output device  418 , at least one controller device  420  and at least one sensing device  422 , wherein the processing device  416 , the input/output device  418 , the at least one controller device  420  and the at least one sensing device  422  are communicated with each other. It should be appreciated that the at least one controller device  420  may include at least one of a traction alternator regulator  424 , a traction motor  426  and a dynamic braking system  428 , an alternator device, a circuit breaker device, a switching device, a power electronics device, a blower, a fan and an electrical contactor. Moreover, the processing device  416 , the input/output device  418  and the at least one controller device  420  on each of the locomotives  402 ,  404 ,  406 ,  408  are further communicated with the remaining locomotives  402 ,  404 ,  406 ,  408  via the MU line  414  such that the processing device  416 , the input/output device  418 , the at least one controller device  420  and the at least one sensor device  422  on at least one of the locomotives  402 ,  404 ,  406 ,  408  is capable of establishing communication with and control of the processing device  416 , the input/output device  418 , the at least one controller device  420  and the at least one sensor device  422  on at least one of the other locomotives  402 ,  404 ,  406 ,  408 , either separately and/or collectively.  
         [0023]     Referring to  FIG. 4  and  FIG. 5 , consider a first situation where a failure of one of the controller devices  420 , such as the traction alternator regulator  424 , occurs on the first locomotive  402 . In this case, the following scenario is likely. As the consist  410  is operating, sensor data is being generated and communicated from the second locomotive  404 , the third locomotive  406  and the fourth locomotive  408  to the first locomotive  402  and is displayed to the operator on the input/output device  418  of the first locomotive  402 . Upon a failure of the alternator regulator  424  on the first locomotive  402 , a failure indication of the alternator regulator  424  is communicated to the operator via the TMI softkey screen  302  on the input/output device  418 , as indicated by the highlighted “Alternator Regulator” softkey  330 . Additionally, because a failure of the alternator regulator  424  will most likely result in a motoring operation failure and a braking operation failure as well, the operator is also informed of a motoring operation failure and a braking operation failure, as indicated by the highlighted “No Motor” softkey  322  and “No DB” softkey  324 , respectively. In this case, the operator has the option of isolating the first locomotive  402  from the rest of the consist  410  via an isolate softkey switch  310  or the operator may try to reset the fault via a reset softkey switch  308 . Additionally, the operator may attempt to restart the system network via a reset network softkey switch  304  or the operator may request fault data via a fault data softkey switch  306 . As such, the operator may be informed of the situation and may perform the appropriate actions without leaving the lead locomotive. The operator may then modify instructions given to the consist system  400  or exit the consist monitor screen  302  via a Modify Order softkey switch  316  and an Exit softkey switch  318 , respectively.  
         [0024]     Referring to  FIG. 6  and  FIG. 7 , consider a second situation where there are four (4) locomotives operating in the locomotive consist  410  and a ground fault occurs involving the third traction motor  426  on the third locomotive  406 . As above, the operator in the lead locomotive may be informed of this condition via the input/output device  418 , wherein the failure of the third traction motor  426  is communicated to the operator via a highlighted “TM3 Ground” softkey indicator  332  on the input/output device  418 . In this case, the operator has the option to cut out the traction motor  426  (i.e. shut the motor down) via a “Cutout” softkey  314  or the operator has the option to try to reset the ground fault via the “Reset” softkey  308 . As above, the operator may attempt to restart the system network via a Reset Network softkey switch  304  or the operator may request fault data via a Fault Data softkey switch  306  allowing the operator to be informed of and control the situation without leaving the lead locomotive. The operator may then modify instructions given to the consist system  400  or exit the consist monitor screen  302  via a Modify Order softkey switch  316  and an Exit softkey switch  318 , respectively. Additionally, it should be appreciated that fault data may be communicated to a storage database and/or a remote receiving center which will log the data for future repair. For example, in the ground fault example above, the fault information may be sent to the next destination of the locomotive, either at the command of the operator or automatically, so that by the time the locomotive arrives at its destination, the parts and/or personnel will be ready to begin work on the motor to correct the fault condition. This would allow for a reduction in the amount of downtime of the locomotive and ultimately would translate into fewer and/or shorter delays.  
         [0025]     Referring to  FIG. 8 , a block diagram illustrating a method  800  for ensuring control of a locomotive  202 ,  204 ,  206 ,  208 ,  402 ,  404 ,  406 ,  408  within a locomotive consist  210 ,  410  is provided. The locomotive consist  210 ,  410  may include a first locomotive  202 ,  402  and a second locomotive  204 ,  404 , wherein the first locomotive  202 ,  402  includes a first locomotive display device  218 ,  418  and a first locomotive processing device  216 ,  416 , and wherein the second locomotive  204 ,  404  includes a second locomotive processing device  216 ,  416  and a second locomotive controller device  220 ,  420  communicated with the second locomotive processing device  216 ,  416 . Additionally, the first locomotive processing device  216 ,  416  is communicated with the second locomotive processing device  216 ,  416  via a Multiple Unit line  214 ,  414  and the second locomotive processing device  216 ,  416  is configurable to allow the first locomotive processing device  216 ,  416  to control the locomotive controller device  220 ,  420 . The method  800  includes monitoring the locomotive controller device  220 ,  420  to determine whether a fault condition of the second locomotive controller device  220 ,  420  has occurred, as shown in operational block  802 . If a fault condition has occurred, then the method  800  includes communicating the fault condition to an operator of the locomotive consist  208 ,  400 , as shown in operational block  804  and operating the first locomotive processing device  216 ,  416  to control the second locomotive controller device  220 ,  420 , as shown in operational block  806 , such that the first locomotive processing device  216 ,  416  is able to control the second locomotive controller device  220 ,  420  from the first locomotive  202 ,  402 .  
         [0026]     Moreover, other features and functions suitable to the desired end purpose may be included, such as a self testing, diagnostic and/or monitoring capability. This would allow the operator the ability to initiate a self-test routine for preventive maintenance and or fault isolation and/or detection. Moreover, the diagnostic capability may be used for trouble shooting and/or fault repair and/or reconfiguration, such as isolation and/or cutout. It should be appreciated that the self testing, diagnostic and/or monitoring capabilities may be implemented by the on-site operator or by a remote operator prior to a fault occurrence, immediately following a fault occurrence and/or after fault data has been received. Additionally, each of the locomotives in the consist  210 ,  410  may be tested as a group or individually in any order. This would allow an on-site operator and/or a remote operator to perform function and safety tests prior to each departure.  
         [0027]     Additionally, it should be appreciated that the locomotive consist system  200 ,  400  may be used to implement operations not currently under control of a control system. For example, the traction alternator field cutout is currently controlled by a circuit breaker which requires that the physical connection be broken manually. It is contemplated that these types of system and/or connections may be controlled via a configurable softkey (i.e. software) switch  303  from the display device  218 ,  418 . Additionally, it is contemplated that the above may be implemented by an on-site operator who may be assisted by remote experts that is in communication with the locomotive consist system  200 ,  400  via a wireless communications system, such as Satellite, RF and IR. Furthermore, the locomotive consist system  200 ,  400  may also be used to monitor the MU line  214 ,  414  to detect if a fault occurrence is due to the MU cables/connection or due to the actual unit indicating a fault occurrence.  
         [0028]     It should be appreciated that all communications may be conducted via a hardwired system or by a wireless system, such as Satellite, Radio Frequency, Infra Red etc. Moreover, in some situations, such as incapacity of the crew, a wireless system may allow a central service office to assume control of the consist  210 ,  410  and/or specific locomotives  202 ,  204 ,  206 ,  208 ,  402 ,  404 ,  406 ,  408  and to operate the consist  210 ,  410  and/or specific locomotives  202 ,  204 ,  206 ,  208 ,  402 ,  404 ,  406 ,  408  remotely, collectively or individually. Thus, all of the information and control available to an operator on the locomotive would be accessible by personnel at the central service (dispatch) office. Additionally, since the amount of information normally passed between locomotive is relatively small, the bandwidth of the communication channel to carry this information may be correspondingly small. However, normal data transmission may be limited to allow more condition information (such as fault/health information) and/or associated commands to be communicated. It should also be appreciated that because all of the locomotives are communicated with each other, the crew may controllably switch control from one locomotive to another in the consist  210 ,  410 . This may be useful if the lead locomotive is not operating correctly and must be shut down. In this situation, operators may switch control of the lead locomotive in the consist  210 ,  410  to one of the remaining locomotives  202 ,  204 ,  206 ,  208 ,  402 ,  404 ,  406 ,  408 , such as second locomotive  204 ,  404 , third locomotive  206 ,  406  or the fourth locomotive  208 ,  408 . For example, if a traction motor  426  has failed, then the operator could cut out the traction motor  426  and proceed with a degraded mode of operation. Another example involves major equipment damage of MIS operation, the unit could be commanded to isolate or standby mode or to ignore throttle commands so that the rest of the consist  210 ,  410  could proceed. Another example would be to limit the total tractive/braking effort produced during certain periods of operation for the safe handling of the train.  
         [0029]     It is contemplated that the at least one controller device  216 ,  416  may include any number and/or type of controller device(s) suitable to the desired end purpose, including but not limited to a throttle control, an environmental control and/or a brake control. Moreover, at least one sensor device  222 ,  422  may include any number and/or type of sensor device(s) suitable to the desired end purpose, including but not limited to a fault sensor device, a traction motor sensing device and/or a cab environment sensing device. Furthermore, in current systems only data was flowing from a remote locomotive to an operator. However, in the disclosed embodiments as described herein, more information flow, information flows between a remote locomotive and an operator and the operator may send commands to the remote locomotive to assume additional operational actions, such as diagnostics, performance, reconfiguration, etc.  
         [0030]     As described above, the method  800  of  FIG. 8 , in whole or in part, may be embodied in the form of computer-implemented processes and apparatuses for practicing those processes. The method  800  of  FIG. 8 , in whole or in part, may also be embodied in the form of computer program code containing instructions embodied in tangible media, such as floppy diskettes, CD-ROMs, hard drives, or any other computer-readable storage medium, wherein, when the computer program code is loaded into and executed by a computer, the computer becomes an apparatus for practicing the invention. Existing systems having reprogrammable storage (e.g., flash memory) may be updated to implement the method  800  of  FIG. 8 , in whole or in part. Also as described above, the method  800  of  FIG. 8 , in whole or in part, may be embodied in the form of computer program code, for example, whether stored in a storage medium, loaded into and/or executed by a computer, or transmitted over some transmission medium, such as over electrical wiring or cabling, through fiber optics, or via electromagnetic radiation, wherein, when the computer program code is loaded into and executed by a computer, the computer becomes an apparatus for practicing the invention. When implemented on a general-purpose microprocessor, the computer program code segments may configure the microprocessor to create specific logic circuits.  
         [0031]     While the invention has been described with reference to an exemplary embodiment, it will be understood by those skilled in the art that various changes, omissions and/or additions may be made and equivalents may be substituted for elements thereof without departing from the spirit and scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims. Moreover, unless specifically stated any use of the terms first, second, etc. do not denote any order or importance, but rather the terms first, second, etc. are used to distinguish one element from another.