SUPPORT APPARATUS FOR A REFLECTOR

BRIEF DESCRIPTION OF THE DRAWINGS

To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. The drawings are not to scale and the relative dimensions of various elements in the drawings are depicted schematically and not to scale.

Other aspects, embodiments and advantages of the invention will become apparent upon reading the detailed description of the invention and the appended claims provided below, and upon reference to the drawings in which:

FIG. 1 depicts in side view typical radial struts and central mount.

FIG. 2 depicts an enlarged view of radial struts and central mount according to some embodiments of the present invention.

FIG. 3 depicts an enlarged view of the coupling of the central mount to the reflector according to some embodiments of the present invention.

FIG. 4 depicts a perspective view of the coupling of the flexible plate to the back of the reflector.

FIG. 5 depicts in side view a typical overall system according to some embodiments of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Accordingly and advantageously, the present invention relates to a reflector support system, typically as utilized with a dish-shaped reflector. To be concrete in our discussion, we will describe in detail the application of the present invention to supporting a dish-shaped reflector as typically used in radio astronomy to collect distant signals. However, the present invention is not limited to radio astronomy and can be used to support dish-shaped reflectors for other purposes including, but not limited to, reception of satellite or other signals, and also in the support of beam-shaping reflectors used in signal transmission. The term “dish shaped” as used herein is not limited to a particular shape such as paraboloid, but includes other shapes that are or might be used as reflectors for the collection and/or transmission of electromagnetic radiation. The improved support structures as described herein can be advantageously employed with general “dish-shaped” reflectors, and is the sense used herein.

In some embodiments of the present invention, the reflector is formed from one or more thin sheets of metal. Advantageously, the reflector is formed from a single sheet of metal. As an example, the metal sheet may comprise aluminum and/or its alloys, steel and/or its alloys, metal composites, and the like. A rim stiffener, typically made from the same material as the reflector, is securely attached (typically by welding) around the rim of the reflector to form a rim stiffener beam (or simply “beam”) around the outside edge of the reflector. Typical cross sectional shapes of the beam include triangular, rectangular, circular, elliptical, among others. Advantageously, the cross sectional shape is triangular. The reflector is typically supported at the rim by a series of struts. Advantageously, the struts are composed of the same material as the reflector so that there are no (or minimal) forces arising due to differences in thermal expansion characteristics. The struts typically extend back to one or more nodes on a central frame. The central frame also provides support to a plate fastened behind the center of the reflector. The plate provides firm radial and torsional support but is advantageously axially flexible. That is, the plate is reasonably stiff when distorted radially (in the direction from the central axis of the reflector towards its rim), or torsionally (rotationally about the reflector's central axis), but flexible in the axial direction (along the reflector's central axis). This plate structure (“flexible plate”) thereby allows the strut system to provide essentially all required axial support to the reflector at the rim. This structure also allows for a large open area behind the reflector, so that various equipment can be installed close to the reflector's vertex, for example, azimuth and elevation bearing systems. This location allows smaller loads and less structural requirements being placed on the pedestal and drive systems in order to resist wind loading.

Referring now to FIG. 1, and FIG. 2, a dish shaped reflector, 100, (as might be used with a radio telescope, for example), is advantageously formed from a single metal sheet comprising aluminum or its common alloys. A rim stiffener, 101, has been welded (or otherwise securely attached) around the rim of reflector 100 to form a rim stiffener beam (or “beam” in brief), typically having a triangular cross sectional shape. Advantageously, the rim stiffener is formed from the same material as the reflector. Support struts, 102, are connected to the rim stiffener beam and extend back to one or more nodes, 103, on a central frame, 104. Advantageously, the support struts are formed from the same material as the reflector and the rim stiffener. Central frame, 104, is typically comprised of a rigid material such as steel and the like. The central frame, 104, also provides axial support to a flexible plate, 105, fastened behind the center of the reflector (that is, “behind” denotes on the convex side of the reflector). This arrangement advantageously creates a large open area behind the reflector that may be used to house various components, such as the mechanical drive systems for elevation and azimuthal positioning.

A more detailed enlarged illustration is shown in FIG. 2. In this illustration, the support struts, 102, extend back to two nodes, 103. However, the number of nodes may be one or more. FIG. 2 also illustrates an embodiment of the attachment of the flexible plate, 105, to the back of reflector, 100. This embodiment illustrates the use of protrusions (or “fingers”), 200, emanating from a substantially contiguous central portion of the flexible plate to increase the axial flexibility while maintaining good radial and torsional stiffness. The required axial flexibility could also be achieved with attachment structures comprising a thin disk, a linear bearing on a large pin, as well as others.

FIG. 3 illustrates additional details regarding the coupling of flexible plate, 105, to the back of reflector, 100. Although the central frame, 104, and the reflector, 100, may be composed of different materials, the flexible plate, 105, serves to reduce or prevent distortion of the reflector due to differences in thermal expansion characteristics of the materials. Another perspective view of the coupling of the flexible plate to the back of the reflector is given in FIG. 4

FIG. 5 illustrates an embodiment of the present invention as applied to a radio telescope. Central frame, 104, is supported and positioned by a pedestal, 400. The large open area behind reflector, 100, allows the mechanical drive systems for elevation and azimuthal positioning, 401, to be located close to the vertex of the reflector. This location allows for smaller loads and less stringent structural requirements being placed upon the pedestal and drives in order to enable them to resist wind loading. This reflector support can be applied to both symmetric and offset optical designs. FIG. 5 illustrates an offset design. Support struts, 402, can be used to support the secondary reflector, 403, as well, but they are advantageously located opposite the reflector support struts, 102.

The foregoing descriptions of specific embodiments of the present invention have been presented for the purpose of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications, embodiments, and variations are possible in light of the above teaching.

SUPPORT APPARATUS FOR A REFLECTOR

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