Abstract:
A mobile satellite communication trailer comprising a frame, an antenna assembly coupled to the frame comprising a feed boom, a reflector dish coupled to the feed boom, and at least one bumper coupled to the feed boom intermediate the feed boom and the reflector dish. A shock isolator is positioned intermediate the frame and the feed boom. The mobile satellite system further comprises at least three adjustable stabilizing legs providing rigid support for said antenna assembly when said antenna assembly is in a transmission position, said stabilizing legs being convertible between said transmission position and said transport position, wherein one of said at least three adjustable stabilizing legs is moveably connected to said trailer front portion and at least two of said at least three adjustable stabilizing legs are moveably connected to at least one of said satellite antenna assembly and said trailer frame proximate said satellite antenna assembly.

Description:
CLAIM OF PRIORITY 
     This application claims priority to U.S. Provisional Patent Application No. 60/751,135, filed Dec. 16, 2005, the entire disclosure of which is incorporated by reference herein. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to a portable dish antenna and, more particularly, is directed to a ruggedized trailer that can support the antenna. 
     BACKGROUND OF THE INVENTION 
     The use of dish-type antennas for transmitting and receiving signals between a ground location and an airborne communications satellite is well-known. Antennas typically have four structural components: a parabolic antenna reflector, an antenna feed boom, an antenna feed, and an antenna pedestal. The parabolic antenna reflector functions much like a parabolic mirror: the reflector collects microwave signals transmitted from an airborne satellite, and reflects the signals toward the antenna feed. The parabolic shape of the reflector operates to focus the microwave signals so that they converge at the reflector&#39;s focal point. An antenna feed boom is attached to the base of the reflector, and the boom serves to position the antenna feed at the focal point of the reflector. The antenna feed houses electronics that transmit and receive the microwave signals. Positioning the antenna feed at the focal point of the parabolic reflector allows the antenna feed to receive a focused microwave signal from a transmitting satellite. The antenna pedestal provides rigid structural support to the reflector, feed, and feed boom. 
     Typically, the antenna reflector should be on the order of 2 to 6 feet in diameter. In order to minimize distortion in transmission and reception, the reflector&#39;s parabolic shape must be held to extremely close tolerances. Once the antenna&#39;s parabolic dish focuses on the satellite, the antenna must remain focused on the satellite to maintain effective transmission and reception of the signals. Thus, the dish must be very rigid, and the antenna pedestal must also provide a rigid mounting that minimizes movement of the dish antenna due to external forces, such as wind. 
     When permanently installed in the ground, the antenna pedestal supports the antenna sufficiently to maintain effective transmission and reception. But portable antennas, which can be readily moved from location to location, provide a significant challenge. Portable antennas are frequently used in mobile television broadcast, such live coverage of concerts, sporting events, and news events in remote locations. In the past, antennas have been directly mounted onto the bed of a carrier vehicle, such as a truck or a flat-bed trailer. Mounting the antenna directly to the bed of a trailer or a truck increases the likelihood that the antenna will move during use due to the vehicle suspension&#39;s response to external forces acting on the antenna or on the truck bed on which it is mounted. The likelihood of movement increases when the truck or trailer bed also supports an equipment housing. Operators working with the equipment frequently create vibrations, which may be transmitted to the antenna. Mobile antennas must be relatively small and light in order to facilitate quick set-up and tear-down by a minimum of personnel; however minimizing the antenna&#39;s size and weight also makes it difficult to securely anchor and stabilize the antenna. 
     A number of mobile satellite antenna designs are well known in the prior art. However, each design has its shortcomings. In particular, mobile antenna designs that rely on frame-mounted stabilizing arms or outriggers frequently allow vibration and forces imparted upon the frame to be transmitted to the antenna. Additionally, prior designs providing for a collapsible antenna often suffer damage to the reflecting dish, antenna feed and electronic components during off-road transportation. Transporting the antenna over rugged terrain subjects the antenna components to significant jarring and shaking, which may result in breakage or damage. Likewise, the electronics external to the antenna feed, such as amplifiers, decoders, and other components, require protection from damaging forces that may be imparted upon them during transportation. Prior mobile antennas provide frame-mounted electronics cabinets, which house integrated electronics racks. Typically, the electronics racks are mounted to the interior of the electronics cabinets. In this arrangement, severe jarring forces or vibrations that are imparted on the vehicle chassis during transportation are transferred directly to the electronic components, and the components may be damaged or destroyed. 
     SUMMARY OF THE INVENTION 
     The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate one or more embodiments of the invention and, together with the description, serve to explain the principles of the invention. 
     These and/or other objects are achieved in a preferred embodiment of a mobile satellite communication trailer comprising a frame defining a trailer front portion and a trailer rear portion, an antenna assembly coupled to the frame comprising a feed boom, a reflector dish coupled to the feed boom, and at least one bumper coupled to the feed boom intermediate the feed boom and the reflector dish, where the bumper protectively engages the reflector dish when the antenna assembly is in a transport position. A shock isolator is positioned intermediate the frame and the feed boom. The mobile satellite system further comprises at least three adjustable stabilizing legs providing rigid support for said antenna assembly when said antenna assembly is in a transmission position, said stabilizing legs being convertible between said transmission position and said transport position, wherein one of said at least three adjustable stabilizing legs is moveably connected to said trailer front portion and at least two of said at least three adjustable stabilizing legs are moveably connected to at least one of said satellite antenna assembly and said trailer frame proximate said satellite antenna assembly. An electronics cabinet comprises a frame, at least one equipment rack received by said electronics cabinet frame, and at least one shock absorber positioned intermediate said electronics cabinet frame and said equipment rack for suspending said at least one equipment rack from said electronics cabinet frame. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A full and enabling disclosure of the present invention, including the best mode thereof directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended drawings, in which: 
         FIG. 1  is perspective view of a mobile satellite trailer in accordance with an embodiment of the present invention, the mobile satellite trailer, shown in a transport mode; 
         FIG. 2  is a left side elevation view of the mobile satellite trailer shown in  FIG. 1 ; 
         FIG. 3  is a right side elevation view of the mobile satellite trailer shown in  FIG. 1 ; 
         FIG. 4  is a detailed left perspective view of the mobile satellite trailer shown in  FIG. 1 ; 
         FIG. 5  is a bottom plan view of the mobile satellite trailer shown in  FIG. 1 ; 
         FIG. 6  is a perspective view of the mobile satellite trailer shown in  FIG. 1  illustrated in a transmission mode; 
         FIG. 7  is a rear perspective view of the mobile satellite trailer shown in  FIG. 1 ; 
         FIG. 8  is a rear perspective view of the mobile satellite trailer shown in  FIG. 1 ; 
         FIG. 9  is a partial perspective view of the mobile satellite trailer shown in  FIG. 1 ; 
         FIG. 10  is a detailed rear view of the mobile satellite trailer shown in  FIG. 1 ; 
         FIG. 11  is a partial rear exploded perspective view of the mobile satellite trailer shown in  FIG. 1 ; 
         FIG. 12  is a partial rear perspective view of the mobile satellite trailer shown in  FIG. 1 ; and 
         FIGS. 13A and 13B  are partial left perspective views of the mobile satellite trailer shown in  FIG. 1 . 
     
    
    
     Repeat use of reference characters in the present specification and drawings is intended to represent same or analogous features or elements of the invention. 
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Reference will now be made in detail to presently preferred embodiments of the invention, one or more examples of which are illustrated in the accompanying drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that modifications and variations can be made in the present invention without departing from the scope or spirit thereof. For instance, features illustrated or described as part of one embodiment may be used on another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents. 
     Referring to the drawings, and particularly to  FIGS. 1-3 , a mobile satellite trailer  10  has a frame  12 , two or more tires  13 , an electronic equipment cabinet  14 , a generator  16 , a generator oil tank  11  ( FIGS. 6 and 9 ) a generator fuel tank  15 , a storage compartment  17  ( FIGS. 6 and 9 ), a collapsible antenna assembly, generally denoted  18 , and an antenna assembly motor (not shown). Frame  12  may be formed of aluminum, steel, or other suitable material and defines a tongue end  20  and a rear end  22  that defines two rear bumpers  23  ( FIG. 8 ). Trailer tongue end  20  has a hitch  24  for connecting trailer  10  to a towing vehicle (not shown). Additionally, a tilt jack  26 , outfitted with a caster  28 , is attached to trailer frame tongue end  20 . 
     Trailer  10  is typically operated in one of two modes: a transportation mode ( FIGS. 1-5 ), where all components are securely fastened to the trailer so as to permit safe and easy transport behind a towing vehicle; and a transmission mode ( FIGS. 6-9 ), where the trailer is securely supported to minimize the movement of the antenna during transmission. 
     Antenna assembly  18  includes a rotating antenna pedestal  30  ( FIGS. 2 and 3 ), which is rigidly anchored to frame  12  by pedestal support  32 . Pedestal  30  supports an antenna pedestal bracket  34  that defines an elevation angle pivot point  36 . Assembly  18  also includes a parabolic reflector  38 , supported by a reflector bracket  40 , which is pivotally connected to elevation angle pivot point  36 . Antenna assembly  18  further includes a feed  112  ( FIG. 8 ) and a feed boom  42 . Feed boom  42  defines two ends: a pivot end  44  that is pivotally connected to pedestal bracket  34  at pivot point  36 , and a feed end  46  ( FIGS. 2 and 3 ) distal from pedestal bracket  34 , which supports the antenna feed. 
     Referring to  FIG. 4 , boom feed end  46  supports feed  112  ( FIG. 8 ), and provides cushioned support for reflector  38  during transportation. Feed end  46  defines two U-shaped support brackets  48 , each having a bumper  50  thereon. In the present embodiment, bumpers  50  are donut-shaped and made of a shock absorbing polymer. Those skilled in the art should understand that bumpers  50  may take on any one of many alternative shapes, such as cylindrical, oblong, rectangular, or triangular. Additionally, it should be understood that bumpers  50  may be a metallic spring with an elastomer sheath or a wire rope isolator interface or bumper  50  may be formed from any shock absorbing material, such as foam, polymer, plastic, rubber, or. One major descriptive characteristic of the bumpers is their value of hardness. “Hardness,” as used herein, is a measure of the resistance of a cured material to withstand indention. Hardness may be measured by a durometer. As should be understood in this art, a durometer measures penetration depth into a material of a pin or drill applied to a surface of the material with a controlled, measured force. As should also be understood, hardness may be expressed in various scales, for example a Shore A scale for soft or elastic materials such as rubber or plastics and a Shore D scale for harder materials. 
     A Shore A durometer is used to measure the hardness of rubber parts by measuring the resistance force against a pin that penetrates the test material under a known spring load. The amount of penetration is converted to a hardness reading based on a scale having 100 Shore A units. Similarly, Shore D durometer is used to measure the hardness of plastic parts. The indentation hardness is inversely related to the penetration and is dependent on the modulus of elasticity and the viscoelastic properties of the material. The force applied, the shape of the indenter, and the duration of the test all affect the results. The Shore durometer consists of a reference presser foot, an indenter, an indicating device, and a calibrated spring that applies the force to the indenter. The difference between the type A and type D durometer is in the shape of the indenter and the calibrated spring, as indicated in the table below. 
     
       
         
               
               
               
             
           
               
                   
               
               
                 Shore 
                   
                 Applied force, 
               
               
                 Durometer 
                 Indenter 
                 F/mN 
               
               
                   
               
             
             
               
                 Type A 
                 Hardened steel rod having a 1.10 mm- 
                 F = 550 + 75 H A   
               
               
                   
                 1.14 mm diameter, with a truncated 
               
               
                   
                 35° cone, 0.79 mm diameter. 
               
               
                 Type D 
                 Hardened steel rod having a 1.10 mm- 
                 F = 445 H D   
               
               
                   
                 1.14 mm diameter, with a 30° 
               
               
                   
                 conical point, 0.79 mm diameter. 
               
               
                   
               
             
          
         
       
     
     The units of hardness range from 0 for the full protrusion of the 2.50 mm indenter to 100 for no protrusion. The force is applied as rapidly as possible, without shock, and the hardness reading is made after a duration of 15 s±1 s. If an instantaneous reading is specified, the scale is read within 1 second of the application of force. 
     Materials may have Shore A hardness values ranging from Shore A 20 for very soft materials increasing to Shore A 90 for harder materials. Shore D hardness values range from 30 to 85 where a material with Shore D 85 hardness would be considered very hard. The upper end of the Shore A scale overlaps with the lower end of the Shore D scale. For example, a typical pencil eraser has a Shore A hardness generally within a range of 25-30. A rubber sole of a shoe can be expected to have a shore A hardness generally within a range of 75-85 and a Shore D hardness generally within a range of 25-30. PVC tubing would have a Shore D hardness generally within a range of 75-85. Referring again to  FIG. 4 , bumpers  50  preferably have a hardness within a range of about 40 to 80 Shore A units, and in one preferred embodiment has a hardness within a range of about 65 to 75 Shore A units. During transportation, reflector  38  rests on bumpers  50 , which ensure that reflector  38  is not damaged during transportation over rugged terrain. 
     Referring back to  FIGS. 1-3 , reflector  38  is secured in place by a brake mechanism (not shown) provided by antenna assembly motor, which prevents reflector  38  from rotating about elevation pivot point  36  during transportation. It should be understood by one skilled in the art that reflector  38  may be secured in a transport mode by other means, such as bolts, clips, clamps, cables, wires or any other suitable device that will lock reflector  38  against bumper  50 . 
     In the transport mode, feed boom end  46  rests in a boom cradle  51  ( FIG. 4 ) that is supported by a feed boom support ledge  52 . Ledge  52  is rigidly connected to trailer frame  12  by a support truss  54 , as depicted in  FIGS. 2-4 . Boom cradle  51  receives feed boom end  46  when antenna assembly  18  is placed in the transport mode, and cradle  51  is cushioned by a feed boom shock isolator  56 , which is positioned atop support ledge  52 . Feed boom shock isolator  56  diminishes the impact and jarring forces that may be transferred to feed boom  42  and reflector  38  through frame  12 . In one embodiment, feed boom shock isolator  56  is a model WR12-400-08 wire rope isolator manufactured by Enidine, Inc. of Orchard Park, N.Y., but one of skill in the art should understand that shock isolator  56  may be a spring, a resilient elastomer, polymer, or other suitable material. Accordingly, boom cradle  51  and support ledge  52  support feed boom end  46 , which, in turn, supports reflector  38  through bumpers  50 . The cushioned support provided by bumpers  50  and shock isolators  56  ensures that both feed boom  42  and reflector  38  are protected from shocks and jarring during transportation. 
     Referring back to  FIGS. 2 and 3 , mobile satellite trailer  10  is further equipped with two collapsible rear stabilizing legs  60  and one front stabilizing leg  62 . Rear stabilizing legs  60  have a telescoping upper member  64  and a fixed length lower member  66 . Upper member  64  has a telescopic joint  65  and defines a first end  68  and a second end  70 . Lower member  66  also defines a first end  72  and a second end  74  that is pivotally connected to upper member second end  70  by a joint  80 . Upper member first end  68  is pivotally connected to the side of antenna pedestal support  32  by a hinge  76  that allows upper member  64  to pivot about both a vertical axis and a horizontal axis (not shown). Lower member first end  72  defines two spaced-apart slots  82  that engage a lower frame hinge  76  as described below. 
     Joint  80  allows for the articulated movement of the upper and lower members of rear stabilizing legs  60  so that the legs may be positioned in a manner that best supports mobile satellite trailer  10  on rugged or uneven terrain. Joint  80  also receives a foot adjustment bolt  84  that is used to attach a foot  86  to joint  80 . Foot  86  is stowed on frame  12  during transportation as shown in  FIGS. 2 ,  3  and  5 . During transportation of trailer  10 , rear stabilizing leg joints  80  are each held in place by a holding bracket  88  mounted on trailer frame  12 , which prevents stabilizing legs  60  from swinging away from trailer frame  12 . Additionally, a stabilizing leg clip  90  holds rear leg lower member  66  adjacent to and below rear leg upper member  64  by a pin connection to one of the multiple adjustment holes  92  formed in upper member  64 . In this manner, rear stabilizing legs  60  are securely fastened against the trailer during transportation and will not inadvertently swing away from trailer frame  12  when traversing rugged terrain. 
     Front stabilizing leg  62  has a first end  94  that is pivotally connected to a front leg frame bracket  98  attached to an underside of trailer frame  12  at a position forward of pedestal support  32 . Front stabilizing leg  62  further defines a front leg second end  96  that receives a foot adjustment bolt  84 , which is used to attach the front leg second end  96  to a foot  86 . Front leg  62  is further supported by front leg adjustment post  99  ( FIG. 1 ) and two adjustable front support members  100  ( FIG. 1 ). Support members  100  each define a first end  102  that is pivotally connected to front leg  62  intermediate front leg first end  94  and front leg second end  96 . Referring to  FIGS. 2 and 3 , support members  100  each further define a second end  104  that is slidably received in a guide  106  attached to frame  12 . Adjustment holes  92  are formed in each front support member  100 , and corresponding adjustment holes (not shown) are formed in adjustment post  99 . Front support members  100  are locked into place by inserting a pin  93  ( FIGS. 6 and 9 ) through adjustment holes  92  of both support members  100  and adjustment post  99 . In this way, front stabilizing, leg  62  is securely held in place and will not rotate away from trailer frame  12  during transportation. 
     Referring now to  FIGS. 6-9 , antenna assembly  18  is shown in a transmission mode. Reflector  38  and feed boom  42  are pivoted about elevation angle pivot point  36  so that the reflector points upward toward a satellite in geosynchronous orbit about the earth. Two cylinders  108 , each having a piston rod  110 , connect reflector  38  and feed boom  42 . As reflector  38  pivots about pivot point  36 , the cylinder piston rods  110  rotate the boom with respect to the reflector until fully extended. Full extension of cylinder piston rods  110  ensures that reflector  38  and feed boom  42  are positioned at a fixed angle determined by the location of the focal point of reflector  38  regardless of the elevation angle the reflector. Proper transmission requires that feed  112  ( FIGS. 8 and 9 ), which is attached to boom feed end  46 , be positioned at the focal point of reflector  38 . Pedestal  30  also pivots to allow antenna assembly  18  to rotate about an axis of rotation (not shown) in order to achieve the proper azimuth angle. Adjustment of the azimuth and elevation angles allows antenna assembly  18  to focus on a particular satellite. 
     During transmission, rear stabilizing legs  60  are positioned to securely and rigidly support antenna pedestal  30 . A scissor jack  31  lifts trailer rear end  22  so that trailer frame  12  is leveled and the trailer&#39;s weight is no longer supported by the suspension (not shown) and tires  13 . The pivotal rotation of hinge  76  about the hinge&#39;s axis of rotation (not shown) allows rear leg upper support member  64  to swing out and away from frame  12 . With particular reference to  FIG. 9 , rear leg  60  also pivots about a hinge pin  77  ( FIGS. 6 and 9 ), which allows rear leg  60  to be positioned such that joint  80  and foot adjustment bolt  84  may be brought into close proximity with the ground, and foot  86  is releasably attached to bolt  84 . The length of rear stabilizing leg upper member  64  may be adjusted by using telescopic joint  65  to extend upper member  64  to the appropriate length. Adjusting the length of upper support members  64  allows the frame rear end  22  to be leveled regardless of the grade of the ground. 
     Turning now to  FIGS. 13A and 13B , rear stabilizing leg lower members  66  are connected to frame  12  under a fender  114  to lock rear stabilizing leg  60  into place. Slots  82  formed in lower member first end  72  slidably receive a pin (not shown) attached to lower frame hinge  76  ( FIG. 14B ). The cooperation between slots  82  and the pin attached to frame hinge  76  allows for quick assembly and teardown of the trailer from the transmission mode. After attaching lower member first end  72  to lower hinge  76 , rear stabilizing leg telescopic joint  65  is adjusted to bring foot  86  into close proximity with the ground. A pin (not shown) is inserted through the appropriate rear stabilizing leg adjustment holes  92  to securely lock rear stabilizing legs  60  into the desired position, and foot adjustment bolt  84  is adjusted to ensure that trailer frame rear end  22  is level and arranged in the proper attitude for transmission. Once rear stabilizing legs  60  are adjusted to level trailer rear end  22  and provide stable support for antenna pedestal  30 , scissor jack  31  is removed. 
     Referring back to drawings  6 ,  8 , and  9 , front stabilizing leg  62  is shown lowered so that front leg second end  96  may securely and rigidly support antenna pedestal  30 . Tilt jack  26  ( FIGS. 1 ,  2  and  3 ) is used to raise trailer tongue end  20  to an appropriate height so that the trailer is maintained in a level position. Foot  86  is then releasably attached to foot adjustment bolt  84  located at front leg second end. Front stabilizing leg support members  100  slide in their respective guides  106  and are secured in place by inserting pin  93  through adjustment holes  92  formed in both support members  100  and adjustment post  99 . Foot adjustment bolt  84  is then used to adjust foot  86  so that trailer frame front end  22  is level and arranged in the proper attitude for transmission. 
     Adjusting rear stabilizing legs  60  and front stabilizing leg  62  will securely position mobile satellite trailer  10  on the ground. Incremental adjustment of rear stabilizing legs  60  and front stabilizing leg  62  will allow operators or other personnel to achieve the proper balance and attitude for the trailer  10 . When fully supported by rear stabilizing legs  60  and front stabilizing leg  62 , the weight of trailer  10  is removed from tires  13  and placed entirely on rear stabilizing legs  60 , and antenna  18  is rigidly positioned with respect to the ground and isolated from external forces and vibrations. 
     Referring back to  FIG. 1 , electronics cabinet  14  is located at the rear of trailer  10 , behind antenna pedestal support  32 . Referring to  FIGS. 6 ,  7 , and  8 , the interior of electronic equipment cabinet  14  is accessible through either a cabinet side door  120  ( FIG. 6 ) or the rear main door  122 , shown in an open position. Additionally, a breaker panel (not shown) is accessible through breaker panel access door  123  ( FIG. 6 ). 
     Referring now to  FIG. 10 , equipment cabinet  14  is shown without any of its outer sheet metal or doors. Cabinet  14  has three bays  124  that may be used to house a unitary electronics rack  126  or other equipment. Unitary rack  126  supports electronic components  128  external to antenna feed  112  ( FIG. 8 ) such as amplifiers, decoders, communications hubs, and other communications hardware. Cabinet  14  also provides an electrical outlet  130  for connecting external equipment and a portal  132  that allows various cables, patch cords, power supply cords from generator  16  and other connection lines (not shown) to pass in to and out of cabinet  14 . Cabinet  14  is supported by a plurality of cross members  134  that provide additional structural rigidity. Typically, cross members  134  are situated such that two members  134  cross the top and bottom of each bay  124 . Each cross member is equipped with multiple shock absorbers  136  that support a mounting rail  138 . Shock absorbers  136  are fastened to cross members  134  by fasteners  137 . Each mounting rail  138  slidably receives a corner of unitary component rack  126 , and rail stop  139  locates rack  126  properly on rails  138 . Once properly positioned on rails  138 , unitary rack  126  may be securely fastened to mounting rails  138  by clips, detents, pins, cap screws or other fasteners. Mounting rails  138  and shock absorbers  136  isolate unitary electronics rack  126  from any jarring or vibration forces imparted on trailer  10 . 
     Referring to  FIG. 11 , which shows an exploded view of electronics equipment cabinet  14 , unitary electronic component rack  126  is shown with electronic components  128  removed. Unitary rack  126  defines a rack front  140 , a rack rear  142  and a plurality of horizontal side members  144  connected to both rack front  140  and rack rear  142 . Rack front  140  provides a plurality of front mounting points  146 , which may be tapped or through holes that are sized appropriately to receive a fastener  147  ( FIG. 12 ), such as a cap screw or shoulder bolt. Typical rack-mounted electronic components  128  are equipped with a front face plate  148  having a plurality of mounting holes  150  sized similarly to front mounting points  146 . Fasteners  147  ( FIG. 12 ) are inserted through both electronic component front face plate mounting holes  150  and the corresponding unitary rack front mounting points  146  so as to securely fasten components  128  to unitary electronics rack front  126 . 
     Each rack side member  144  defines a rear support track  152  that slidably receives a slider  154  affixed to a side panel  156  of each electronic component  128 . Slider  154  is typically attached to electronic component side panel  156  by a screw or other appropriate fastener and may be fashioned out of DERLIN® or other polymer that allows for smooth sliding such as TEFLON®, or Urethane. As an electronic component  128  is installed into unitary equipment rack  126 , track  152  slidably receives slider  154 . When component  128  is fully inserted into rack  126 , track  152  locks slider  154  in place to rigidly secure the rear portion of component  128  into rack  126 . Track  152  may be machined to tight tolerances with a decreasing width so that slider  154  is compressed as it slides further into track  152 . Furthermore, track  152  may also have a shape that releasably receives slider  154 , such as a sideways J-shape, as shown in  FIG. 11 . It should be understood by those of skill in the art that track  152  may take on any shape that promotes locking engagement between track  152  and slider  154  such as a C-shaped track. 
       FIG. 11  depicts an engagement between slider  154  and track  152 , shown in phantom at the rear of electronic components  128 . Thus, the cooperation between rear support tracks  152  and sliders  154  secures the rear portion of electronic components  128  and minimizes the stress imparted upon component front face plates  148  during transportation. Securing both the front and rear of each component  128  also minimizes the movement of components  128  relative to each other and to rack  126 , thereby creating a unitary structure. 
     Referring to now to  FIG. 12 , once electronic components  128  are installed in unitary electronics rack  126 , and fasteners  147  have been installed to secure component front face plates  148  to rack front  140  ( FIG. 11 ), rack  126  may be installed as a single module into electronics cabinet  14 . As previously described, mounting rails  138  slidably receive the corners of rack  126 , and rack  126  may be secured to rails  138  by clips, detents, or fasteners (not shown). In this arrangement, when trailer  10  traverses a bump, shock absorbers  136  dampen out the shock imparted upon the unitary electronics rack  126 . As mentioned above, components  128  will not move relative to each other or relative to rack  126 . This arrangement provides a shock absorbing feature for unitary rack and components  128  as a unitary module, rather than providing shock absorbing devices for each individual component  128 . 
     While one or more preferred embodiments of the invention have been described above, it should be understood that any and all equivalent realizations of the present invention are included within the scope and spirit thereof. The embodiments depicted are presented by way of example and are not intended as limitations upon the present invention. Thus, those of ordinary skill in this art should understand that the present invention is not limited to the embodiments disclosed herein since modifications can be made.