Abstract:
A support structure apparatus for a reflector antenna having a main reflector. The support structure includes a plurality of sub-brackets and a main bracket. The sub-brackets each having a plurality of main reflector connection points and a main bracket connection point. A plurality of fasteners used to join the main reflector to the sub-brackets and the sub-brackets to the main reflector swivel when loose and become rigid when fastened. Fasteners between the sub-bracket and the main bracket may be replaced with captive screws or motors with threaded shafts to provide azimuth/elevation adjustment functionality to the support structure.

Description:
BACKGROUND 
     The main reflector of a reflector antenna is typically mounted via a support structure. To avoid performance degradation, it is important that the shape of the main reflector of a reflector antenna is maintained. For cost reduction purposes, the main reflector may be molded or stamped from materials such as plastic or metal having relatively low stiffness characteristics. To add support for these reflectors, and thereby maintain their shape, a support structure having multiple contact points distributed across the main reflector may be applied. 
     Prior rigid support structures having multiple contact points distributed across the main reflector necessarily have imperfect shape accuracy due to manufacturing tolerances. In the case of exactly three mounting points, the reflector is normally not deformed by structure inaccuracies. However three attachment points may not be sufficient for the structure to stiffen the reflector across its surface under load conditions such as wind forces. If the number of contacts exceeds three, the reflector, the support structure, or both necessarily deform when the structure is attached to the reflector, unless additional steps are taken to fit the mis-toleranced attachment points to the reflector, such as shimming, or unless sufficiently tight fabrication tolerances are imposed upon the backstructure. In either case cost is increased. 
     In more advanced embodiments, support structures may include manual or motor control azimuth/elevation adjustment functionality. However, this functionality may require duplicative and or comparatively complex structures with corresponding increases in the total number of discrete parts required. 
     The increasing market for reflector antennas used with, for example, consumer satellite TV and or internet satellite communications systems has focused attention on cost reductions resulting from increased materials, manufacturing and distribution efficiencies. Further, reductions in assembly requirements and the total number of discrete parts are desired. 
     Therefore, it is an object of the invention to provide an apparatus that overcomes deficiencies in the prior art. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the general and detailed descriptions of the invention appearing herein, serve to explain the principles of the invention. 
         FIG. 1  is a schematic back view of a main reflector with support structure according to a first embodiment of the invention. 
         FIG. 2  is a close-up side schematic view of  FIG. 1 , one of the three hole/screw connections between the main reflector and sub-bracket omitted for clarity. 
         FIG. 3  is a schematic back view of a main reflector with support structure according to a second embodiment of the invention. 
         FIG. 4  is a close-up side schematic view of  FIG. 3 , one of the three hole/screw connections between the main reflector and sub-bracket omitted for clarity. 
         FIG. 5  is close-up side schematic view of a manually adjustable support structure, one of the three hole/screw connections between the main reflector and sub-bracket omitted for clarity. 
         FIG. 6  is a close-up side schematic view of a motor controlled adjustable support structure, one of the three hole/screw connections between the main reflector and sub-bracket omitted for clarity. 
     
    
    
     DETAILED DESCRIPTION 
     As shown for example in  FIGS. 1 and 2 , a first embodiment of the invention provides a distributed nine point connection to a main reflector  10  via three sub-bracket(s)  15  that are each coupled to a main bracket  20 . Three connection points between each sub-bracket  15  and the main reflector  10  allow each sub-bracket  15  to be self-leveling. Thereby, the sub-bracket(s)  15  will not deform the main reflector  10  when secured. 
     Fasteners which swivel when loose but become rigid when connected allow the connection points to mate together without requiring narrowly pre-defined alignment. For the purposes of this specification, “swivel when loose” indicates that the fastener may be freely movable over a range of different angles, prior to connection, and allowing rigid connection at any position or orientation within the range of different angles, as required by the alignment of the elements being coupled. In a first embodiment, each of the connection points between the main reflector  10  and the sub bracket(s)  15  and between the sub-bracket(s)  15  and the main bracket  20  is formed as an oversized, with respect to a diameter of the selected fastener, hole  25  or slot surrounded by a domed area  30 . Fasteners such as screw(s)  35  or bolt(s) and nut(s)  40  each have a corresponding domed section  45  that mate with the domed area(s)  30 . Thereby, each fastener has a range of angular movement within each oversized hole  25  but is securely fastenable against each respective domed area  30  to form a rigid assembly when the fasteners are fully tightened. 
     Because of the adjustable nature provided by the range of movement of each fastener, the sub-bracket(s)  15  may be standardized into a single component, even if they are each attached at different areas of the main reflector  10 . Similarly, the main bracket  20  is self leveling when mounted upon the sub-bracket(s)  15 . Because the fasteners are attachable over a wide range of angles, the same sub-bracket(s)  15  and main bracket  20  are usable upon a wide range of different main reflector  10  embodiments. 
     One skilled in the art will appreciate that the sub-bracket(s)  15  and main bracket  20  may be cost effectively manufactured without requiring a high degree of manufacturing tolerance due to their adjustable nature. Each sub-bracket  15  and or main bracket  20  may be formed from, for example, stamped metal. 
     As part of the stamping process, additional reinforcement such as stiffening groove(s)  50  and or turned edge(s)  55  may be incorporated into the components. Further, turned edge(s)  55  of the main bracket  20  may be formed as mounting point(s)  60  for a feed and or sub reflector boom arm  65  as shown for example in  FIGS. 3 and 4 . 
     Depending upon the main reflector  10  characteristics, it is possible to omit one of the sub-bracket(s)  15  and make a single point connection directly between the main reflector  10  and the main bracket  20 . Where a direct connection between the main reflector  10  and main bracket  20  is applied, depending upon the size and shape of the main reflector  10 , the sub-bracket(s)  15  may be formed with an increased depth, for example as shown in  FIGS. 3 and 4 . A direct connection between the main reflector  10  and the main bracket  20  may be made near the proximal end of the boom arm  60 , in order to minimize any mis-focusing effect on antenna gain and pattern performance due tolerance errors in the main reflector  10 , main bracket  20 , and or attachment parts. 
     In an alternative embodiment, preferably wherein the main reflector  10  is formed with appropriate stiffness, main reflector  10  azimuth/elevation adjustment functionality may be incorporated at the interconnection between the sub-bracket(s)  15  and main bracket  20 . 
     As shown for example in  FIG. 5 , nut(s)  40  coupled to the sub-bracket and screw(s)  35  held captive by the main bracket  20  may be adjusted relative each other to modify the main reflector  20  azimuth/elevation relative the main bracket  20 . Similarly, as shown for example in  FIG. 6 , the screw(s)  35  may be replaced with motor(s)  70  having a threaded shaft  75 . Applied in a two sub-bracket configuration similar to that shown in  FIG. 3 , turning both motor(s)  70  or screw(s)  35  simultaneously in a common direction adjusts elevation while turning them in opposite directions to each other adjusts azimuth. 
     By incorporating the azimuth/elevation adjustability into the support structure, the requirement for a separately adjustable azimuth/elevation mounting head is eliminated. That is, the reflector antenna may be mounted by direct connection between the main bracket  20  and a desired fixed mounting point. 
     The present invention provides a simplified distributed multiple mounting point support structure that may be cost effectively manufactured without precision manufacturing tolerances. In the case of a reflector skin which is fabricated accurate to shape but does not have sufficient rigidity to withstand additional loads such as wind forces without a backstructure with more than three attachment points, the invention provides multiple independent sub-structures each with a reduced number of mounting points, significantly improving the overall strength and rigidity of the resulting antenna. Because the substructures are independently attached to the reflector skin and then coupled to a main bracket, the various components may be easily assembled into a rigid assembly with minimal risk of distorting the main reflector shape. 
     Where the reflector skin is sufficiently rigid, the substructure to main structure interconnections also provide junction points for incorporation of elevation/azimuth control(s) eliminating the costs and potential problems of separate azimuth/elevation adjustment structures. 
     Significant packaging, inventory and distribution economies are realized because the bare main reflector(s)  10  may be stacked one upon the other, allowing, for example, installation crew vehicles to carry a significantly larger supply of the reflector antennas. 
     
       
         
               
             
               
               
             
           
               
                   
               
               
                 Table of Parts 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 10 
                 main reflector 
               
               
                 15 
                 sub-bracket 
               
               
                 20 
                 main bracket 
               
               
                 25 
                 hole 
               
               
                 30 
                 domed area 
               
               
                 35 
                 screw 
               
               
                 40 
                 nut 
               
               
                 45 
                 domed section 
               
               
                 50 
                 stiffening groove 
               
               
                 55 
                 turned edge 
               
               
                 60 
                 mounting point 
               
               
                 65 
                 boom arm 
               
               
                 70 
                 motor 
               
               
                 75 
                 threaded shaft 
               
               
                   
               
             
          
         
       
     
     Where in the foregoing description reference has been made to ratios, integers, components or modules having known equivalents then such equivalents are herein incorporated as if individually set forth. 
     While the present invention has been illustrated by the description of the embodiments thereof, and while the embodiments have been described in considerable detail, it is not the intention of the applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details, representative apparatus, methods, and illustrative examples shown and described. Accordingly, departures may be made from such details without departure from the spirit or scope of applicant&#39;s general inventive concept. Further, it is to be appreciated that improvements and/or modifications may be made thereto without departing from the scope or spirit of the present invention as defined by the following claims.