Patent Application
20060164319
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.
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.
As shown for example in
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
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
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
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.
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'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.
