US 3375523 A
Description (OCR text may contain errors)
J. LAIBSON March 26, 1968 ANTENNA STRUCTURE MOVABLE IN AZIMUTH AND ELEVATION DIRECTIONS 5 Sheets-Sheet 1 Filed Oct. 16, 1964 A INVENTOR.
JEZEV 44/55 0/1/ March 26, 1968 .1. LAIBSON ANTENNA STRUCTURE MOVABLE IN AZIMUTH AND ELEVATION DIRECTIONS Filed Oct. 16, 1964 5 Sheets-Sheet 2 24 6? I W A40 6 635 4 A4 95 '/0/- 97 gg /6 /?z 57 --/a3 JZ-ZZV 44/5150 INVENTOR.
ATTdZ/VEK? March 26, 1968 J. LAIBSON 3,375,523
ANTENNA STRUCTURE MOVABLE IN AZIMUTH AND ELEVATION DIRECTIONS Filed Oct. 16, 1964 5 Sheets-Sheet 3 Era. .6.
' March 26, 1968 J. LAIBSON 3,375,523
ANTENNA STRUCTURE MOVABLE IN AZIMUTH AND ELEVATION DIRECTIONS Filed 001;. 16, 1964 5 Sheets-Sheet 4 W E Era 7 JZZZJ 44/550 INVENTOR.
Arraz/vfx s March 26, 1968 J. LAIBSON 3, 75,5
ANTENNA STRUCTURE MOVABLE IN AZIMUTH AND ELEVATION DIRECTIONS Filed Oct. 16, 1964 5 Sheets-Sheet 5 Era. 9. $1??? United States Patent 3,375,523 ANTENNA STRUCTURE MOVABLE IN AZIMUTH AND ELEVATION DIRECTIONS Jerry Laibson, San Diego, Calif., assignor to Whittaker Corporation, Los Angeles, Calif., a corporation of California Filed Oct. 16, 1964, Ser. No. 404,469 6 Claims. (Cl. 343765) ABSTRACT OF THE DISCLOSURE A parabolic reflector is mounted for movement in either azimuth or elevation or both simultaneously. The elevation axis is close to the center of gravity of the antenna system for minimizing inertial effects and drive requirements, with a single centrally located large sector elevation gear and other equipment being mounted as a part of the reflector counterweight. A circular gear is mounted on the turntable directly over a pit housing and is engaged by an azimuth drive system. The turntable supports a tripod type tower which allows adjustment in elevation of the reflector over a large range. The reflector alternatively instead of being supported on a tripod type tower may be supported on a yoke.
The present invention relates to an improved antenna construction.
It is therefore a general object of the present invention to provide an improved antenna construction of the character indicated above.
A specific object of the present invention is to provide a reflector movable about a horizontal or elevation axis which is close to the center of gravity of the antenna system thereby minimizing deflections and inertial and drive requirements and making possible the direct use of a large elevation gear, the electronic cages and other miscellaneous equipment as a part of the reflector counterweight, with the large elevation gear serving also to increase the pointing accuracy of the drive system and minimizing costs of a speed reduction unit, and further with the elevation gear forming an integral part of the reflector supporting structure for overall stability and satisfaction of frequency requirements.
Another specific object of the present invention is to provide an antenna of this character wherein its turntable is capable of supporting a large computer room and the elevation drive system and which in general simplifies the data take-off design.
Another specific object of the present invention is to provide an antenna construction of this character which is compact with resulting high strength to weight ratio, i.e. lightness, and antenna efiiciency.
Another object of the present invention is to provide an antenna construction of this character using a low tower whereby maintenance and adjustment of the antenna may be accomplished from the ground using simple scaffolding.
Another specific object of the present invention is to provide an antenna construction of this character wherein the azimuth structure includes a tripod-t0wer structure which provides stability in all directions with X-band rigidity requirements.
Another specific object of the present invention is to provide an antenna construction of this character wherein the turntable is mounted on a center king post and an outer circular track with the same forming a direct load path for truss loads and overturning moments.
Another specific object of the present invention is to provide an improved reflector structure wherein there are close ties between a large torus ring and radial panel supporting beams for increased rigidity, antenna stability, frequency characteristics, and pointing accuracy, resulting in large part due to the torsional strength of the torus and balance between outer and inner structural areas.
Another specific object of the present invention is to provide a reflector construction making use of a torus ring configuration that permits a fixed stable tie for mounting of spars and trusses to thereby reduce spar deflections and increase natural frequency and pointing accuracy.
Another specific object of the present invention is to provide a reflector construction using a spar system having rectangular truss work with large depth in the radial plane to thereby achieve a high natural frequency for the overall spar system with maximum reduction of shadow area.
Another specific object of the present invention is to provide a reflector construction in which the center hub area provides (a) rigidity to the torus ring, (b) a support for the antenna feed, (c) an integral unit with the electronic room, and (d) a mounting platform for a parabolascope type instrument during panel alignment.
Another specific object of the present invention is to provide a reflector construction of this character wherein the radial beams for panel support provide rigidity in all directions, with also the interaction between radial and circumferential trusses providing great torsional rigidity and increased torsional natural frequency.
Another specific object of the present invention is to provide a simple construction for minimizing costs of fabrication, field assembly and shipping with elements being of complete, bolted or welded construction.
The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. This invention itself, both as to its 0rganization and manner of operation, together with further objects and advantages thereof, may be best understood by reference to the following description taken in connection with the accompanying drawings, in which:
FIG. 1 is a perspective view of the reflector and its mounting in a partly assembled condition.
FIG. 2 is a view partly in side elevation and partly in section transversely through a portion of the reflector of FIG. 1, with additional reflecting panels thereon, and also illustrates the azimuth drive system.
FIG. 3 illustrates in more detail the mounting of the reflector mount on a track shown also in FIG. 2.
FIG. 4 illustrates in more detail the motor drive of the azimuth drive system shown also in FIG. 2.
FIG. 5 is a view partly in front elevation and section of the reflector assembly.
FIG. 6 illustrates details of the elevation drive system.
FIG. 7 is generally a view in side elevation of the drive system shown in FIG, 6.
FIGS. 8 and 9 illustrate a preferred form of track and truck structure used in rotatably supporting the turntable, FIG. 8 being generally a view in side elevation and FIG. 9 being a view taken in the direction indicated by the lines 9-9 in FIG. 8.
The antenna reflector 10 is mounted for rotation in azimuth and iii-elevation, azimuth adjustment being provided by the rotatable turntable or pedestal 12 mounting a pair of towers 13 and 14, and elevation adjustment being provided by rotatably supporting the reflector 10 on the upper ends of such towers 13 and 14.
The turntable or pedestal 12 is centrally supported for rotation on a stationary king post 15 (FIG. 2) anchored in the ground, using suitable bearings (not shown) for that purpose, and the turntable has secured thereto six track engaging trucks 16, equally spaced around the circumference of a circle, one of which is illustrated in FIGS. 2 and 3.
partly in As seen in FIG. 3, the truck 16 includes a rail engaging roller 18 rot'atably supported in bearings 19, 20 on a mounting plate 21 which in turn is releasably and adjustably mounted on the turntable plate 22 using shims, if necessary, for adjustment. Also, the plate 21 is provided with a downwardly extending angled bracket member 24 carrying a bearing 25 for a roller 26 which engages the underside of a flanged portion of circular rail 28 in the general form of an I-beam in cross-section.
The rail 28 is mounted at different spaced locations along its circular length on an adjustable support 30 which includes an upper plate 31 and a lower plate 32 engaging on mating pitched or cam surfaces 34, the plate 32 being anchored to the ground, the overall height of the support 30 being adjusted by the bolt 34 passing through apertured portions of plates 31, 32, and such adjustment being secured by bolt 36.
The adjustments are so made that substantially all of the weight of the turntable is supported by the rail 28 and substantially equally at six different points, with tilting of the turntable being prevented under adverse conditions by engagement of the roller 26 with the rail 28.
The drive for the turntable 12 is shown in FIGS. 2 and 4 and involves generally a circular bull gear 44 on the turntable 12 meshing with a motor driven gear 45, the gear 44 being mounted on a reinforced flange 47 extending downwardly from the turntable plate 48, and the gear being on the output shaft 49 of a speed reducer unit 50 having its input shaft 51 driven by a motor 52. A solenoid operated brake 53 is associated with shaft 51 to brake movement of the shaft and lock the turntable in position. The reducer unit 50, brake 51, motor 52 as well as a bearing 54 for shaft 49 are mounted on a common supporting member 56 which is secured to an inner wall of an underground pit 57. Azimuth adjustment is obtained by releasing brake 53 and energizing motor 52 which may be a reversible motor. 7
The turntable 12, as indicated in the drawings, is formed of a plurality of interconnected truss members to which plates are secured for connection to the two towers 13, 14 and their braces 39, 40, 41 and 42.
The reflector 10 is rotatably supported about a common horizontal axis on each of the towers 13, 14 for elevation adjustment using bearing means which may include a shaft supported on each of the towers at its support 58, with such shaft extending into a bearing sleeve 59 mounted on its supporting plate 60, the plate 60, as illustrated, being secured to the torus ring 62 of the reflector 10.
Also secured to the reflector torus ring 62 is a large circular gear 64 (FIG. 2) meshing, as shown in FIGS. 6 and 7, with a pair of motor driven gears 66, 67, the gear 66 being used to drive the reflector in the aft direction and the gear 67 being used to drive the reflector in the forward direction. Each of these two gears 66, 67 are driven by a like arrangement involving, correspondingly, a speed reducer unit 70, 71 and a corresponding motor 72, 73, with a solenoid operated brake 74, 75 being associated with the output shaft of the corresponding motor 72, 73.
These various motors, speed reducer units and brakes shown in FIG. 6 are mounted on a common support plate 77 secured to the upper end of a supporting structure 79 on and extending upwardly from turntable 12.
This elevation drive gear 64 is, as previously indicated, secured to the reflector torus ring 62 using, as indicated in FIG. 5, a series of generallyv triangularly shaped truss members 81 each having their apexes connected to the ring gear 64 and their base portions secured to inner and outer rings 62A, 62B of the torus ring 62; and additional support is provided for the gear 64, as shown in FIG. 2, by a series of support members 83 and 84 extending between the gear 64 and a corresponding frame member 85, 86, each of which has one of its ends interconnected at a common point 87 on gear 64 and which has its other end connected to the inner ring 628 of the torus 62 to define therewith a generally triangular structure having its plane lying within the plane of the circular gear 64. The extremities of the circular gear 64 are connected, as also indicated in FIG. 2, to the outer ring 62A of torus 62.1
Also, as indicated in FIG. 5, the series of radial trusses 81 may be interconnected intercostally by a-first series of interconnected intercostal members 89 and also by a second series of intercostal members 90 which are disposed tively to the members 85, 86 (FIG. 2) to thereby provide enhanced support at the rotational axis of the reflector.
Extending radially inwardly is a series of center hub truss supports 95,each of which is connected at its outer end to the torus ring member. 628 (FIG. 2);. with the inner ends of such truss supports being connected to the center hub structure 97 which includes the antenna feed housing 99 and electronic cage 101, such cage 101 and an associated air conditioner unit 102 being disposed aft of the elevation axis and being additionally supported by a brace structure 103 extending between the supporting members 85, 86., These center; hub truss supports 95, as seen in FIG. 5, are interconnected by intercostal members 105.
Extending radially outwardly from the torus ring 62 and connected to the .outer torus ring member 62 is a series of major panel support trusses 107. (FIGS. 2 and 5) which are interconnected at different radial distances by intercostal truss members 109..
A subreflector 111 positioned forwardly of the elevation axis is supported on and near the ends of four generally triangularly shaped spars 114, having their=base portions connected to torus ring 62 at equally spaced circumferential points thereon, with the apieces of the. spars being interconnected forwardly at their junction 116.
The reflecting surface of the reflector is defined by three series of panels 117, 118, 119, as indicated in FIG. 1, of conventional honeycomb structure, the panels, generally gore-shaped, being suitably secured in alignment on the radial trusses 107, torus 62 and center hub trusses 95 to form a parabolic reflecting surface.
A computer room 121 is mounted on the turntable 12 between the towers 13,14 and cables (not shown) extend to such room for controlling or adjusting the position of the reflector and also for controlling the transmission of energy from the antenna and for collecting data from use of the antenna.
It will be seen that the .vertical axis of the king pin 15 about which the turntable isrotatable, when projected, passes through the horizontal or elevation axis of the reflector which itself passe very near or actually through the center of gravity of the reflector assembly.
It will be appreciated that the. reflector may be supported other than by the towers illustrated. For example, a generally Y-shaped or yoke structure may be used having a portion partially encircling the reflector and having the reflector supported .on the upper arms thereof.
Preferably the housing 121 is of hexagonal shape making most eflicient use of the space above the turntable 12 upon which the same is constructed.
Also, to provide addedirigidity to the supporting structure 79, four brace members extend between the upper end of the structure 79 and an intermediate point on a corresponding one of the four tower braces 39, 40, 41 and 42.
Referring to FIGS. 8 and 9, the construction is.a modification of the arrangement shown in FIG. 3. The rail 132 of standard cross-section, formed in arcuate sections, is adjustably mounted on a concrete base 134 using shims 136 of different thickness to assure the positioning of the top of the completed track in a horizontal plane. These shims 136 are between the lower rail flange and a corresponding one of circumferentially spaced base members 138 secured by bolts 139 to the concrete base or footing 134, and such shims are maintained by angled clamping members 141, 142 bolted to the base member 138 to engage opposite sides of the lower rail flange with the shim 136 being sandwiched between, one the one hand, the base member 138 and, on the other hand, the rail 132 and the clamping members 141, 142.
The turntable 12 mounts a plurality of circumferentially spaced truck structures 140, each of which includes a frame member 141A pivotally mounted about the axis 139A at its central portion on mounting bracket 142 which is secured to the turntable. This frame member 141A rotatably mounts three rail engaging wheels or rollers 143, 144, 145, the wheels 143, 145 engaging the top side of the rail, as shown in FIG. 8, and the intermediate wheel or roller 144 engaging the underside of the top rail flange, as seen in FIG. 9. For the latter purpose, the roller 144 is rotatably supported in a bracket member 166 integrally formed with the truck frame 141. It will be noted that the pivotal axis of the frame member 141 is in a vertical plane with the rotational axis of roller 144.
An annular dirt or dust screen 150 (FIG. 9) has its upper end secured to the turntable 12, with its lower end extending between the spaced walls 152, 153 of an annular trap structure 154; and an angle baflie member 156 extends partially around the outer wall 153 to provide a dirt or dust trap preventing dirt and dust from entering the central underside portion of the turntable 12.
While the particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from this invention in its broader aspects and, therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of this invention.
1. In an antenna construction of the character described, a turntable having wheels engageable with a circular rail; a vertical king post on which said turntable is rotatable; a yoke type reflector supporting structure extending upwardly from said turntable; a reflector structure rotatably supported on opposite legs of said supporting structure about a horizontal axis; said reflector structure having a reflector surface lying forwardly of said horizontal axis and having a single centrally located semicircular gear extending aft of said horizontal axis with the center of curvature of said circular gear corresponding to said horizontal axis; said gear lying in a vertical plane central of said reflecting surface; a second supporting structure on said turntable and drive means mounted on said second supporting structure and engaging said gear to drive the same about said horizontal axis, said reflector structure including a torus ring rotatably supported on said supporting structure; a first series of radial trusses mounted on said torus ring and extending radially outwardly therefrom; a second series of radial tr-usses mounted on and extending radially inwardly of said torus ring; an antenna feed housing supported on the inner ends of said second series of trusses; reflecting members secured on said first and second series of trusses; said circular gear being secured to said torus ring; said torus ring including an inner and an outer ring member; a pair of frame members each having one of their ends connected to said inner ring member and the other one of their ends extending rearwardly and connected to a central portion of said gear; and a series of truss members between each of said frame members and said gear.
2. In an antenna construction of the character described, a turntable having wheels engageable with a circular rail; a vertical king post on which said turntable is rotatable; a yoke type reflector supporting structure extending upwardly from said turntable; a reflector structure rotatably supported on opposite legs of said supporting structure about a horizontal axis; said reflector structure having a reflector surface lying forwardly of said horizontal axis and having a single centrally locate-d semicircular gear extending aft of said horizontal axis with the center of curvature of said circular gear corresponding to said horizontal axis; said gear lying in a vertical plane central of said reflecting surface; a second supporting structure on said turntable and drive means mounted on said second supporting structure and engaging said gear to drive the same about said horizontal axis; said rail having a flange; means adjustably supporting said rail at a plurality of spaced points therealong; means adjustably supporting said wheels on said turntable; said wheels engaging the top side of said flange; and roller means mounted on said turntable and engaging an underside of said rail; said wheels and said roller means being mounted as a unit on said turntable.
3. An antenna construction as *set forth in claim 2, in which said turntable has a circular gear mounted on its underside; and motor driven gear means engaging said gear on said turntable.
4. In an antenna construction of the character described, a turntable having wheels engageable with a circular rail; a vertical king post on which said turntable is rota-table; a yoke type reflector supporting structure extending upwardly from said turntable; a reflector structure rotatably supported on opposite legs of said supporting structure about a horizontal axis; said reflector structure having a reflector surface lying forwardly of said horizontal axis and having a single centrally located semicircular gear extending aft of said horizontal axis with the center of curvature of said circular gear corresponding to said horizontal axis; said gear lying in a vertical plane central of said reflecting surface; a second supporting structure on said turntable and drive means mounted on said second supporting structure and engaging said gear to drive the same about said horizontal axis; said rail having a flange; a frame member having a central portion thereof pivotally mounted about a pivotal axis on the underside of said turntable and having three rollers rotatably mounted thereon; each of two of said rollers being on ends of said frame member and contacting the topside of said rail; the third one of said rollers contacting the underside of said flange.
5. A construction as set forth in claim 4, in which the rotational axis of said third roller extends vertically in a vertical plane with the pivotal axis of said frame member.
6. An antenna construction as set forth in claim 5, including an annular dirt shield having one of its ends secured to the turntable and the other one of its ends extending between spaced annular walls of a stationary dirt trap member which cooperates with the lower end of said shield to provide a dirt trap.
References Cited UNITED STATES PATENTS 3,105,969 10/1963 Banche et al 353765 X 3,141,168 7/1964 Ashton 353-765 X FOREIGN PATENTS 933,616 8/1963 Great Britain.
ELI LIEJBERMA'N, Primary Examiner.
HERMAN K. SAAIJBACH, PAUL GENSLER,