US3235872A

US3235872A - Dish reflector formed of similar arcuately arranged thin skinned sections

Info

Publication number: US3235872A
Application number: US268276A
Authority: US
Inventors: Joseph A Schepis
Original assignee: GEN ELECTRONIC LAB Inc
Current assignee: GEN ELECTRONIC LAB Inc; GENERAL ELECTRONIC LABORATORIES Inc
Priority date: 1963-03-27
Filing date: 1963-03-27
Publication date: 1966-02-15
Anticipated expiration: 1983-02-15

Description

Feb. 15, 1966 J. A. SCHEPIS 3,235,872 DISH REFLECTOR FORMED OF SIMILAR ARCUATELY ARRANGED THIN SKINNED SECTIONS Filed March 27, 1963 4 Sheets-Sheet 1 INVENTOR. JOSEPH A. SCHEP/S Feb. 15, 1966 J. A. SCHEPIS DISH REFLECTOR FORMED OF SIMILAR ARCUATELY ARRANGED THIN SKINNED SECTIONS 4 Sheets-Sheet 2 Filed March 27, 1963 INVENTOR. JOSEPH A. SCHEP/S BY ,4 TTOR/VEY Feb. 15, 1966 J A. SCHEPIS 3,235,872

DISH REFLECTOR I 'ORMED OF SIMILAR ARCUATELY ARRANGED THIN SKINNED SECTIONS Filed March 27, 1963 4 Sheets-Sheet 5 INVENTOR. JOSEPH A. SCHEP/S BYM/M ATTORNEY Feb. 15, 1966 J. A. SCHEPIS 3,235,872 DISH REFLECTOR FORMED OF SIMILAR ARCUA'IELY ARRANGED THIN SKINNED SECTIONS Filed March 27, 1965 4 Sheets-Sheet 4 INVENTOR. JOSEPH A. SCHE'P/S United States Patent 3,235,872 7 DISH REFLECTGR FORMED OF fiiMlLAR ARCU- ATELY ARRANGED THIN SKINNED SECTIUNS Joseph A. Schepis, South Braintree, Mass, assignor to General Electronic Laboratories, Inc., Cambridge,

Mass., a corporation of Delaware Filed Mar. 27, 1563, Ser. No. 268,276 8 Claims. (Cl. 343-912) This invention relates to antenna reflectors and more particularly to antenna reflectors having a modular type construction, with each module having a surface providing a portion of the antenna reflector surface and a proportionate share of the antenna strength.

In the field of large antenna reflectors, it has been heretofore customary to provide a framework structure having a sufficient strength to support the reflective surface material which itself lends substantially no strength to the overall antenna. The resulting antenna reflector structure has thereby been relatively expensive as well as heavy, cumbersome, bulky and relatively difficult to transport and reassemble at desired locations of use.

These problems have been overcome by the present invention of an antenna reflector structure which also incorporates other desirable features and advantages.

Among these other desirable features and advantages is the provision of an antenna reflector structure which has a relatively small number of major components for assembly and disassembly, only three types of major components being required, namely reflective surface skins, ribs, and rear cover skins. Also each of these three types of components in the entire antenna reflector structure may have the same dimensional configuration, thereby providing desirable ease and economy in manufacture, assembly and disassembly, as well as storage and portability. A further desirable feature is that the reflective surface skin components combine with the ribs and outer skin members into a unitary module in manner to contribute materially to the overall strength of the assembled antenna reflector. A further desirable feature is that the antenna reflector structure lends itself to thin sheet metal ribs, reflector skins and rear cover skins which may be rapidly formed as inexpensive stampings and known sheet metal stretching techniques for their formation into the desired shapes. Also the structure lends itself to the maintenance of very close reflective surface tolerances which are effectively maintained even under heavy wind and storm loading conditions.

Objects of the present invention include the provision of an antenna reflector structure which is relatively light in weight, compact, inexpensive and lends itself to rapid assembly and disassembly as well as compact storage and portability of disassembled components.

Another object is the provision of an antenna reflector structure which lends itself to construction into similar modules with each module forming a proportional share of the reflective surface and contributing to the overall strength of the structure.

Other objects include the provision of an antenna reflector structure wherein the reflective surface members are of very thin skin-like construction and provide substantial support strength to the overall antenna reflector structure.

These and other objects, features, and advantages will become more apparent from the following description of preferred embodiments of the invention and wherein:

FIG. 1 is an isometric view of an antenna reflector structure in accordance with the present invention and shown with a partially cut-a-way section to more clearly show construction;

ice

FIG. 2 is a side view of one of the ribs of the antenna reflector structure shown in the FIG. 1 embodiment;

FIG. 3 is a cross-sectional view to enlarged scale of the rib shown in FIG. 2 and taken on line 33 of FIG. 2;

FIG. 4 is a cross-sectional view to enlarged scale of the ribs shown in FIG. 2 taken on line 44 of FIG. 2;

FIG. 5 is a cross-sectional view to enlarged scale and taken on line 5-5 of FIG. 2 to more clearly show construction of the rib stiffener formation;

FIG. 6 is a view to enlarged scale of a portion of the rib shown in FIG. 2 to show an alternative edge construction suitable for use in the present invention;

FIG. 7 is a cross-sectional view to enlarged scale of aportion of the ribs shown in FIG. 6 and taken on line 7--7 of FIG. 6;

FIG. 8 is a side view of an alternative rib construction suitable for use in the present invention;

FIG. 9 is a plan view showing construction of a reflective skin member suitable for use in the FIG. 1 embodiment;

FIG. 10 is a cross-sectional view to enlarged scale of a portion of the reflective skin member shown in FIG. 9 and taken on line 10-10 of FIG. 9;

FIG. 11 is a plan view showing construction of one of the rear cover skin members suitable for use in the FIG. 1 embodiment;

FIG. 12 is a cross-sectional view to enlarged scale taken on line 1212 of FIG. 11;

FIG. 13 is an isometric view to enlarged scale of portions of two ribs, reflective surface skin and rear cover skin members, together with other components to more clearly show construction of a modular assembly;

FIG. 14 is an isometric view to enlarged scale of the components of FIG. 13 in assembled form as a portion of an antenna reflector module;

FIG. 15 is an isometric view of an antenna reflector module shown in position for assembly to a center mounting cylinder;

FIG. 16 is an isometric view illustrating an antenna reflector module in place as part of the over-all antenna reflector structure mounted on a center mounting cylinder held in use position on a pedestal;

FIG. 17 is a cross-sectional view to enlarged scale and in isometric taken on line 1717 of FIG. 1 showing a suitable clamping structure for holding edges of adjacent skin members together;

FIG. 18 is a cross-sectional view to enlarged scale and in isometric taken on line 17-17 of FIG. 1 to illustrate an alternative arrangement of the rib members with respect to the reflective surface and cover skins;

FIG. 19 is a cross-sectional view to enlarged scale and in isometric taken on lines 1'717 of FIG. 1 to illustrate an alternative clamping arrangement for holding the edges of reflective surface skins in abutting relation to each other.

Referring to FIG. 1 in more detail, an antenna reflector structure in accordance with the present invention is designated generally by the numeral 20.

The antenna reflector 20 is composed of three major components namely, a plurality of similar thin reflective surface skin members 22, a plurality of similar thin rear cover skin members 24, and a plurality of similar thin rib members 26 preferably of aluminum or magnesium alloy materials. This combination, as will be hereinafter described, of these three types of major elements is such that they all contribute in proportional manner to the overall strength of the antenna reflector 20. These elements have been so arranged that strength contribution o the reflector skins 22 and rear cover skins 24 is derived primarily from tension loading of those elements, thereby permitting the use of very thin sheet material for those elements with a cross section 28 of the reflector surface skins 22 as low as .032 inch even for an overall reflector diameter 30 of twenty feet or more.

A representative rib 26 is shown with more particularity in FIGS. 2 through 7. Each rib 26 has preferably a plurality of weight reducing holes 32 with outwardly formed or flanged edges 34 for increasing lateral stiffness thereof. Each rib 26 also has columnar shaped dimples 36 running crosswise of the rib 26. The rib 26 also has

edges

38 and 40 at substantially right angles to .the plane of the rib 26 which may be bent or formed as an extension of the rib 26 material as shown in FIG. 13. Alternatively the

edges

38 and 40 may be constructed as a separate angular member 42 (FIGS. 6 and 7) fastened as by rivets 44 to one leg 46 of the angular member 42. The leg 46 also carries slots 48 at suitable intervals to permit the other leg 50 to conform to the contour of the edges 38 and 4th of the rib 26.

And where additional rigidity and dimensional accuracy of the contour of the reflective surface skins 22 is desired, a separate thick strip member 52 may be fastened to the flanges 40 and carry accurately machined surfaces held to close tolerances for providing the proper contour support to the reflective skins 22 (FIGS. 18 and 19).. It should be noted that leg 50 of the angular member 42 may be similarly machined within the limits of its dimensions. In such instance there may be two ribs 26 for each of the skins 22. One of the ribs 26 is arranged to provide support at substantially the centerline 54 of the reflective skin 22. The other rib 26 may be arranged to carry at its flange 40 a U-shaped locking strip 56 machined to the proper contour in manner similar to that of the contour 52 but having additionally therein a channel 58 carrying abutting

ends

60 and 62 respectively of

lock adapter strips

64 and 66 of L cross sectional shape along the edges 68 and held in place on the skins 22 as by rivets 70 and on the ribs 26 by screws 72 through holes 74 at the abutting edges 68 of the reflector skins 22, and by screws 75 in holes 76 fastened to the strip support member 52.

For additional conservation of weight, where the strength problem permits, the U-shaped continuous strip 56 may be replaced by a plurality of short length locking block members 78such as shown in FIG. 18 and shown carrying a threaded hole 80 to receive an anchoring screw 82. The short length locking block member 78 has a land 84 for retention of adjacent edges of the reflector skins 22 separated by a pre-selected distance 86 and thereby providing independent locking for each of the skins 22.

The rear cover skin 24 (FIG. 11 and 12) which may likewise carry lock member edges 64 fastened to each side of the skin 24 by rivets 70 may be similarly fastened to the rear edges of the ribs 26. The rear cover skins 24 preferably carry a large number of weight reducing holes .88 with stiffener formations 90" in manner similar to the holes 32 and stiffener formations 34 in the ribs 26.

Alternatively to placing the ribs 26 as shown in FIG. 19, assemblies of modules 92 (FIGS. 13, 14, and 15) wherein the ribs 26 may be fastened as by screws 94 and flanges 38 :and 40 respectively to the reflective skins 22 and rear cover skins 24.

The front end of each module 92 may carry

support rods

96 and 98 and

brackets

100 and 102 fastened in place .by

screws

104 and 106 as shown in FIGS. 13, 14, and 15 to provide a suitable mounting arrangement of the module '92 to a cylindrical support member 108 carried by trunnions 110 in a pivotal yoke 112 disposed to rotate as desired on a base or pedestal 114.

It will be noted that the modules such as 92 may be constructed separately and stored separately for rapid assembly and disassembly as shown in connection with FIGS. 13, 18, and 19 into a completed antenna shown in 4 FIGS. 1 and 16. Alternatively the components such as reflector skins 22, rear cover skins 24, and ribs 26 are so fashioned in contour and shape that they may be stacked on each other for even more compact storage and conservation of space or for shipment to a desired location for assembly as described.

An alternative construction of the ribs 26 is shown in FIG. 8 wherein the body of the rib 26 is similar to that of the embodiment shown in FIG. 2 except in that the outside or rear edge 116 follows a desired curvilinear pattern rather than the series of straight edge surfaces 38 in FIG. 2. Such curvelinear construction lends itself to even more uniform stress distribution and weight saving in components.

This invention is not limited to the specific details of construction and operation described as equivalents will suggest themselves to those skilled in the art.

What is claimed is:

1. An antenna reflector comprising a plurality of similar thin skin-like members having abutting edges and a curvilinear shape such that each forms an equal segment of the antenna reflect-or, locking means at the abutting edges for holding the abutting edges in place together, rib members having a thin body portion with an edge at each side of the body portion, one of the edges of each of the rib members conformed to the cross sectional curvilinear shape of the associated thin skin-like member and fixed to said associated thin skin-like member with the body portion of the rib in substantially perpendicular relation to said associated thin skin-like member, a second plurality of thin skin-like members conformed and fixed to respective ones of the other edge of each of said ribs to form thereby a rigid unitary antenna reflector structure wherein the skin-like members and ribs co-operate to provide the overall strength and rigidity of the antenna reflector.

2. The combination as in claim 1 wherein the skin members and ribs are of at least one of the group of materials namely aluminum alloy and magnesium alloy.

3. The combination as in claim 1 wherein the abutting edges have reinforcing strips the entire length of each edge with angularly disposed parallel legs and clamping members rigidly holding said legs in place together.

4. The combination as in claim 1 wherein the ribs have L shaped strips with one leg of the strip conformed and fixed to the respective skin member and the other leg of the strip fixed to the rib.

5. The combination as in claim 3 wherein the edges of the skin members and angularly disposed parallel legs are in engagement with each other.

6. The combination as in claim 4 wherein the edges of the skin members and angularly disposed parallel legs are spaced from each other.

7. The combination as in claim 3 wherein the clamping member for each pair of abutting parallel legs runs substantially the full length of the edges and reinforcing strips.

8. The combination as in claim 7 wherein the clamping strips each have a trough with the abutting parallel legs closely fitted in the trough and screw means fastening the legs downwardly on the trough.

References Cited by the Examiner UNITED STATES PATENTS 2,083,226 6/1937 Dornier 8937 2,125,691 8/1938 Ragsdale 89-37 2,572,430 10/1951 Balton 343915 2,985,881 5/1961 Holland 343-915 2,997,712 8/1961 Kennedy 343-916 3,105,969 10/ 1963 Blanche et al 3439l5 HERMAN KARL SAALBACH, Primary Examiner.

Claims

1. AN ANTENNA REFLECTOR COMPRISING A PLURALITY OF SIMILAR THIN SKIN-LIKE MEMBERS HAVING ABUTTING EDGES AND A CURVILINEAR SHAPE SUCH THAT EACH FORMS AN EQUAL SEGMENT OF THE ANTENNA REFLECTOR, LOCKING MEANS AT THE ABUTTING EDGES FOR HOLDING THE ABUTTING EDGES IN PLACE TOGETHER, RIB MEMBERS HAVING A THIN BODY PORTION WITH AN EDGE AT EACH SIDE OF THE BODY PORTION, ONE OF THE EDGES OF EACH OF THE RIB MEMBERS CONFORMED TO THE CROSS SECTIONAL CURVILINEAR SHAPE OF THE ASSOCIATED THIN SKIN-LIKE MEMBER AND FIXED TO SAID ASSOCIATED THIN SKIN-LIKE MEMBER WITH THE BODY PORTION OF THE RIB IN SUBSTANTIALLY PERPENDICULAR RELATION TO SAID ASSOCIATED THIN SKIN-LIKE MEMBER, A SECOND PLURALITY OF THIN SKIN-LKE MEMBERS CONFORMED AND FIXED TO RESPECTIVE ONES OF THE OTHER EDGE OF EACH OF SAID RIBS TO FORM THEREBY A RIGID UNITARY ANTENNA REFLECTOR STRUCTURE WHEREIN THE SKIN-LIKE MEMBERS AND RIBS CO-OPERATE TO PROVIDE THE OVERALL STRENGTH AND RIGIDITY OF THE ANTENNA REFLECTOR.