Abstract:
An apparatus and method for equipping a locomotive with a modular radio communication system capable of being expanded to incorporate future improvements in radio and data communication electronics. The modular radio communication system provides for the installation of a standardized mounting plate and housing onto the rooftop of the locomotive to reduce the need to make extensive mechanical and electrical modifications to the locomotive when the radio communications system is updated. Sunscreens and vent openings in the standard mounting plate and housing work to reduce the temperature of the internal components of the modular radio communications system.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
         [0001]    None.  
         STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT  
         [0002]    Not Applicable.  
         BACKGROUND OF THE INVENTION  
         [0003]    The present invention relates to a radio communication system for locomotives, and in particular, to a locomotive radio communication system which allows for upgrading on-board radio communications systems without the need for extensive removal and replacement of a large number of communication system components.  
           [0004]    Many locomotives used in the railroad transportation industry are equipped with radio communication systems. In addition to the current widespread use of voice radio communications, the need for wireless data communications to and from locomotives is expected to increase substantially over the next several years. It is likely that in the near future, all locomotives will be equipped with some type of radio data communication system.  
           [0005]    While locomotive radio data communications systems currently exist, this technology is still in development. These recent developments are resulting in significant and rapid changes in design and implementation. The constant changes which are occurring preclude specific long term communication requirements from being accurately defined today. Therefore, while there is a present need to equip locomotives with radio data communication systems, it is impossible to determine the exact configuration of future radio communication systems.  
           [0006]    The conventional process of installing a radio communication system onto a locomotive requires installing a radio, an antenna, an RF coaxial cable connecting the radio to the antenna, and the interface cabling between the radio and the application equipment. This installation involves finding a suitable location inside the locomotive for the radio and a suitable location on the roof for the antenna. The radio mounting brackets are fitted in the cab, an access hole is drilled in the roof, coaxial cable is run from the radio through the cab to the roof, the antenna is installed, and appropriate connections are made. This current process is very costly because of the man hours of labor required, and the non-productive downtime of the locomotive.  
         BRIEF SUMMARY OF THE INVENTION  
         [0007]    Briefly stated, the current invention seeks to solve the problem of how best to meet the railroad industry&#39;s near term needs for radio communication services that are definable today, while at the same time, providing the customer with equipment that can be quickly upgraded at a later time with additional and/or improved functionality, and without extensive changeover efforts. The present invention describes an apparatus and method in which currently available radio data communications systems are installed in locomotives in a manner which greatly simplifies the expansion or modification of those radio communications systems in the future.  
           [0008]    This invention uses a complete locomotive cab rooftop assembly which allows for several sets of radios and antennas. In its initial installation, the expandable communication system is equipped with only one or two radio communication devices, including the antennas. The installation of the expandable radio communication system is easier than the conventional retrofit installation of a single radio and antenna because the RF coaxial cable is not routed through the cab to the roof. Moving the radio to the roof, and eliminating the coaxial cable routing into the cab allows for flexible positioning of the cab electronics unit, as the cable length and bending limits of the coaxial cable no longer apply.  
           [0009]    The foregoing and other objects, features, and advantages of the invention, as well as presently preferred embodiments thereof, will become more apparent from the reading of the following description in connection with the accompanying drawings.  
       
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS  
       [0010]    In the accompanying drawings which form part of the specification:  
         [0011]    [0011]FIG. 1 is side view of a locomotive showing the general arrangement of the present invention when installed.  
         [0012]    [0012]FIG. 2 is perspective view of the present invention showing the roof mounted radio communications system.  
         [0013]    [0013]FIG. 3 is an exploded perspective view of the present invention showing the sunscreens.  
         [0014]    [0014]FIG. 4 is a side sectional view of the present invention with the antenna dome removed. 
     
    
       [0015]    Corresponding reference numerals indicate corresponding parts throughout the several figures of the drawings.  
       DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0016]    The following detailed description illustrates the invention by way of example and not by way of limitation. The description clearly enables one skilled in the art to make and use the invention, describes several embodiments, adaptations, variations, alternatives, and uses of the invention, including what is presently believed to be the best mode of carrying out the invention.  
         [0017]    Referring now to the drawings, FIG. 1 shows the typical installation of the present invention on a locomotive  1 . Each locomotive  1  used in the railroad industry is equipped with a cab  2  in which the locomotive operator resides. The cab  2  has a roof  3  which encloses the operator and a set of locomotive controls  4  from the elements. A modular radio communications unit  5  is connected to a radio communications hub  6 .  
         [0018]    Modular radio communications unit  5  is attached to a standard mounting plate  8  which is attached to the roof  3  of the locomotive  1 . The standard mounting plate  8  is attached to the roof with bolts, rivets, or by welding, or any other suitable means which securely mounts the standard mounting plate  8  to roof  3 . In an alternate embodiment, standard mounting plate  8  is designed to also accommodate high gain steered antenna systems that utilize Ku-band or Ka-band mobile antennas.  
         [0019]    The modular radio communications unit  5  (FIG. 2) comprises a first sunscreen  9 , a second sunscreen  10 , an antenna dome  11 , a housing  12 , and standard mounting plate  8 . The sunscreens act to prevent the radio electronics within housing  12  from being directly exposed to the intense solar heat normally found on the roof of the locomotive. To further cool the radio electronics, housing  12  has a first plurality of vent openings  13  and a second plurality of vent openings  14 . These vent openings allow air to flow beneath sunscreens  9  and  10 . This air flow acts to further dissipate the solar heat.  
         [0020]    The sunscreens  9  (FIG. 3) and  10  are attached to housing  12  by a first plurality of mounting screws  15 . The housing is attached to standard mounting plate  8  by a second plurality of mounting screws  16 . The housing  12  includes a plurality of risers  17  and a spacer  18 . The risers and the spacer hold the sunscreens  9  and  10  above housing  12  to allow air to enter the housing through vent openings  13  and  14 . The air cools the modular radio communications unit  5  by circulating between the sunscreens  9  and  10 , and housing  12  to dissipate heat absorbed by the housing. An air ventilation gap  19  (FIG. 4) is created by risers  17  and spacer  18 . The air ventilation gap  19  is about 0.25 inches in height.  
         [0021]    Housing  12  has a first insulating air gap  22  and standard mounting plate  8  has a second insulating air gap  23 . The insulating air gaps  22  and  23  trap air within the housing  12 . This trapped air acts as insulation to inhibit propagation of heat from roof  3  of the locomotive  1  into the housing.  
         [0022]    The housing also has at least two radio electronics compartments  20 . Using appropriate fasteners, at least one radio electronics unit  21  is installed within one of the radio electronics compartment  20 . An antenna  24  is mounted on top of housing  12 . Antenna dome  11  is installed onto housing  12  to protect antenna  24 . While modular radio communications unit  5  may initially include only one radio electronics unit  21  and one antenna  24 , additional radio electronic units  21  and additional antennas  24  may subsequently be incorporated within the modular communications unit. Radio electronics units  21  may be an individual unit, or interconnected with other radio electronics units in the housing  12 . The actual number of initially installed radio electronics units  21  will be in accordance with the particular needs of the railroad company.  
         [0023]    Antenna  24  is connected to radio electronics units  21  using an RF coaxial cable  25 . Connections of antenna  24  to radio electronics units  21  are made in or near modular radio communications unit  5  and do not require the routing of the RF coaxial cable  25  through roof  3 . This eliminates the need to drill holes in the roof  3  as is required when a conventional radio system is installed on the locomotive. This also reduces radio and antenna placement problems caused by the limitations on the length and the bending limits of coaxial cable.  
         [0024]    The communications hub  6  (FIG. 1), such as the General Electric Harris Pathfinder ®, is installed within cab  2  of the locomotive. The communications hub  6  is connected to the roof mounted modular radio communications unit  5  by a standard multichannel highband width baseband serial cable  7 . Cable  7  allows communications between radio electronics units  21  and communications hub  6 . Cable  7  also provides power to the modular radio communications unit  5 . It is important to note that cable  7  is the only cable routed through the roof  3  of the cab  2 , thereby eliminating the need to drill several holes in the roof for multiple antenna cables and power cables every time the radio on locomotive  1  is replaced or upgraded.  
         [0025]    In operation, the present invention functions in a manner similar to all two-way radio communication devices and will allow for the possibility of both voice and data communications. To enhance these communications, a unique locomotive registration number assigned to a specific locomotive is stored in the communications hub  6 . The modular radio communications unit  5  contains baseband interface modules, factory integrated to the radio electronics units  21 , that translate the radio baseband protocol to the standard protocol of communications hub  6 . The translation provided by the baseband interface modules also contains a factory programmed unique radio identification code. A host data center located at a railroad service center monitors the radio communications from locomotive  1 . The unique locomotive registration number and the unique radio identification code allow for automatic commissioning of any radio upgrade when locomotive  1  is in a location that provides a radio communication path to the host data center.  
         [0026]    The full benefit of the invention is realized when the next generation of radio communication requirements are to be met and the older radio(s) installed within the modular radio communications unit  5  must be replaced with new radios designed to meet the new radio communications requirements. The modular radio communications unit  5  is simply removed from the standard mounting plate  8  and exchanged for a model with the desired new capabilities. The replacement steps consists of disconnecting the serial cable  7  from the obsolete modular radio communications unit  5 , removing the obsolete modular radio communications unit  5 , installing the new modular radio communications unit  5 , and reconnecting the serial cable  7 . It is estimated that this task could be performed in thirty minutes by a semiskilled single technician while locomotive  1  is being serviced between trips.  
         [0027]    In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results are obtained. As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.