US 2577469 A
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e. A. KUMPF Dec. 4, 1951 ANTENNA 2 SHEETS-SHEET 2 Filed. May 18, 1946 Patented Dec. 4, 1951 ANTENNA George A. Kumpf, Erlton, N. J., assignor to Radio Corporation of America, a corporation of Delaware Application May 18, 1946, Serial No. 670,676
This invention relates to a new and useful portable directional ultra high frequency antenna which is particularly useful with radar equipment.
An object of this invention is to provide a light weight portable directional dipole antenna using a minimum space for carrying and storing, and a minimum of time for erecting the same.
Portable antennas known in the prior art generally consumed a large amount of time to erect. Also, the amount of space occupied by the parts was generally objectionable.
By my improved antenna invention, the antenna structure is greatly reduced as to space requirement, and it requires a minimum amount of time to erect.
A feature of the invention is that a vertical steel tube which supports the antenna by the aid of three clamp brackets. The dipoles and supports are folded to lay flat. The antenna frame and reflecting screen are folded in two half-sections by means of two link-hinges, one of which is located at the extreme upper portion of the frame and the other at the lower portion. In the operating position, the frame is secured in position by two thin steel tubes clamped at the top and bottom of the frame by turning ordinary wing thumb screws.
This invention will be clearly understood by referring to the accompanying drawing in which:
Fig. 1 is a plan view of the antenna of this invention shown in the operating position;
Fig. 2 is a front elevation of Fig. 1;
Fig. 3 is a side elevation of Figs. 1 and 2;
Fig. 4 is a detailed plan view of the hinged portion of the frame;
Fig. 5 is a front view of Fig. 4;
Fig. 6 is a sectional view taken on line 66 of Fig. 2 showing the support post, antenna support tube, clamp and bracket;
Fig. 7 is a view partly in cross-section taken along line of Fig. 3 showing the dipole connections;
Fig. 8 is a cross-section taken on line 8-8 of Fig. 2; and
Fig. 9 is a crosssection taken on line 99 of Fig. 2.
Referring now in detail to Figs. 1, 2 and 3 of the drawing, there is shown an antenna system having a screen reflector l5 composed of two half-sections A and I53, each half-section being hinged to be folded along a line midway between sections. Each half-frame is composed of thin steel tubing having the required strength. The ends of .the steel tubing are.
mitered and gas welded together as indicated at IE to form a rectangular frame. One reflector which was constructed according to this invention was approximately seventy-five inches long and forty-eight inches wide. This reflector was for an antenna designed for operation at a frequency range of about 200 megacycles. It is to be understood that antenna frames of other dimensions and for other frequencies may be employed. Each half-frame is provided with six folding dipole radiator or receptor elements l1, each preferably constituted by two elongated conductors totalling a half wavelength overall. Dipole elements I? are supported by elongated con ductive members I8 which are welded to plates 49A of a hinge arrangement 19. Plates [9A are hinged to further plates l 93 which are welded to horizontal members 26 of reflector l5 so that dipole elements I! which are supported in front of reflector [5 in the operating position may be raised to'lie adjacent the reflector in the nonoperating position. There is provided above each of hinged dipole brackets H], a spring clamp 2! which retains the dipole elements in the raised position. The reflecting screen surface of the antenna array is composed of a plurality of small metallic tubes or steel wires 20 of varying sizes which are arranged horizontall and equally spaced in the vertical direction approximately two and five-eighths inches apart, the tubes and wires being welded at their ends to the rectangular frame IEA, N33. The length of support members I8 is such as to space the radiating elements from the reflecting screen surface approximately one-quarter of the operating wavelength and, therefore, each pair of members constitutes in effect an insulator insofar as the radio frequency energy is concerned. An adjustable member 22, which is preferably a steel strap or shorting bar, is arranged to be adjustable to make the electrical length from shorting bar 22 to dipole l1 exactly a quarter wavelength at the operating frequency. In some applications, member 22 may be constructed of insulating material. The antenna array thus far described is coupled to transducer apparatus by means of a feeeder network of concentric balanced transmission line, each dipole arm being preferably connected by the flexible transmission line cables 23 as shown iii-Fig. 7, wherein a length of coaxial cable 23 is shown passing within one support member l8 to a point near its outer end. At this point sheath conductor is bonded to the contiguous dipole element and the center conductor 66 is connected to the conductor of a feed through insulator 61,
which in turn is connected to the opposing dipole element I! by means of a conductive spring member 68. In this manner the dipoles are excited in the conventional mode. The transmission lines are so arranged that the energy is fed to the dipoles to obtain the desired radiation pattern. The transmission line cables 23 are all formed of lengths of flexible coaxial line comprising a center conductor and an outer conductor, the conductors being maintained in a concentric arrangement by suitable insulation material.
Referring now in detail to Figs. 4 and 5, the two rectangular frames ISA and I5B are preferably hinged together by an improved hinged member which is composed of two metallic plugs 24, each being pinned and welded to the inner surface of tubes [5A and I5B, respectively. The forward end of each plug 24 is provided with a flat portion and an aperture to receive two link members 25, the links being secured to members 24 by studs '26 provided with a shoulder portion 25' which is slightly greater in length than the thickness of the projecting portion of members 24. The length of. the spacing between the shoulder portions is such as to prevent links 25 from binding. The ends of studs 26 are riveted over to prevent them from coming loose or becoming detached. The central portion of the hinge is provided with shouldered stud 2'! which also has a shoulder at 21' and is riveted over. Members 25 are suitably shaped to provide a stop arrangement to limit the opening of the hinge. A preferred arrangement of such stop is shown as. comprising link projection 25 and pin 28.
Referring now in detail to Fig. 6, there is shown a triangular shaped support casting 30 which supports the antenna on a vertical steel tube 29. The support casting 3B is provided with apertures 3|, 32 and 33. Aperture 32 has a split portion 34' which is formed by two extending ears 35 and 36. The ear 35 is threaded to receive a machine screw 31, and the ear 36 is drilled for sufficient clearance so that when the machine screw 31 is tightened, a support tube or pipe 29 will be clamped thereto. The casting 30 is provided with another casting 40 which serves as a clamping portion. The purpose of this latter casting is to enable the frame to be disassembled from the pole or pipe 29. This is accomplished by loosening threaded wing bolts or screws 48 and 49 which are located on both ends of casting 40. These wing bolts are arranged to be captive by burring over their ends, which prevents the bolts from being detached from casting 48 and becoming lost. The center wing screw stud or bolt 43 is arranged on casting 40 with a spring 44. A hinge pin is provided on the end of stud 43 when the latter is loosened and prevents the casting 40 from being separated from the support casting 30 which stays with the pole 29 when disassembled. The lower portion of pole 29 terminates in a combined rain shield and mounting support member 50. The combined rain shield and support member 5H has four pivoted wing members 5| which are arranged to secure four support legs 52 thereto. There are three groups of support castings 30 and 40 used to support the antenna. The upper portion of each one of the castings 30 is provided with engaging pins M and 42 for securing the castings to each half-frame I5A, 153.
In the operation of this device, as shown by Fig. 8, the antenna array is assembled by loosening the wing nuts 62 on each one of the support straps 6i, thus permitting the retaining tube to slide thereon. As shown by Figs. 1 and 2, the antenna array with the half-portions I5A and [5B are then opened up at the hinged portion so that the tube 66 is in a central position with respect to each half-frame ISA, I5B and the wing nuts 62 tightened. Each dipole is then loosened from the clamped position by releasing spring 2|, and swung down on the hinge arrangement 19 to the position shown in Fig. 3 and in greater detail in Fig. 9 and locked by spring 2|. Suitable connections to the radio aparatus are then made to the transmission lines 23 (which in themselves form no part of the invention) and the antenna is then ready for operation. In placing the antenna structure in the non-operating position again, each antenna dipole is folded upward and held by the action of spring 2| engaging a support member [8, whereby the assembly then lies parallel with the frame, and tube 60 is moved to its closed or non-operating position. The thumb or wing nuts 62 are then tightened and the half-frames [5A and I5B are then secured in their closed position.
What is claimed is:
1. A portable high frequency antenna comprising a central tube, a plurality of spaced apertured support members secured to said central tube along the length thereof, a pair of half frames on opposite sides of said central tube and secured to said support members and pivotally movable in the apertures of said support members, a plurality of parallelly spaced supports secured to each of said half frames, means on said apertured support members to clamp said half frames, a plurality of dipoles each pivotally supported as a unit by a hinge connected to said parallelly spaced supports to permit folding, a plurality of support straps secured to each half frame, a movable metallic tube clamped by said support straps to top and bottom portions of said frames to retain them in the same operating plane.
2. A unitary transportable ultra high frequency antenna array comprising a central support member, a plurality of spaced apertured support members secured to said central support member along the length thereof, a reflector screen including a pair of half frames on opposite sides of said central support member and secured to said support members and pivotally movable in the apertures of said support members, a plurality of parallelly spaced supports secured to each of said half frames, means on' said apertured support members to clamp said half frames, a plurality of dipoles each pivotally supported as a unit by a hinge connected to said parallelly spaced supports on the front of said screen to permit folding, means adjacent said hinges to retain said dipoles in a folded non-operating position, a plurality of support straps secured to each half frame, a movable metallic tube clamped to said support straps at top and bottom portions of said half frames to retain them in the same operating plane, a transmission line feeder network and a switch box secured to the rear of said screen, a rain shield arranged at the base of said support member, and a plurality of pivoted wing members pivoted on said rain shield for mounting said antenna.
3. An antenna structure comprising a flat screen reflector, a plurality of spaced dipoles each having support members attached thereto, said support members being pivotally mounted on said screen to permit the dipoles and supports to lie flat against said screen or in a position wherein said supports are at 90 degrees to the plane of said screen, the dipoles being arranged mechanically parallel to each other.
4. A foldable antenna structure comprising a flat screen reflector, a plurality of spaced dipoles each having supporting members attached at the ends thereof, said supporting members being pivotally mounted on said screen at the ends of said members remote from said dipoles to permit the dipoles and supports to lie flat against said screen or in a position wherein said members are at 90 degrees to the plane of said screen, the dipoles being arranged mechanically parallel to each other, a second similar construction of flat screen reflector and pivotally mounted dipoles, and a plurality of hinge members secured to adjacent edges of said fiat screens for permitting said screens to remain in a single plane or to fold together.
5. An antenna structure comprising a flat screen reflector, a plurality of spaced dipoles each having supporting members attached thereto, said supporting members being pivotally mounted at one end thereof on said screen to permit the dipoles and supports to lie flat against said screen or in a position wherein said supporting members are at 90 degrees to the plane of said screen, the dipoles being arranged mechanically parallel to each other, a second similar construction of fiat screen reflector and pivotally mounted dipoles, and a plurality of hinge members secured to adjacent edges of said flat screens forpermitting said screens to remain in a single plane or to fold together, and means secured to both of said screens at their adjacent edges for mounting said screen in a vertical position.
6. A portable high frequency antenna structure comprising a central supporting member, a refleeting screen including a pair of half frames arranged on opposite sides of said supporting member and pivotally movable thereon, a plurality of parallel spaced supports secured to each of said half frames, means on said supporting member to clamp said half frames, and a plurality of dipoles each pivotally supported as a unit by a hinge connected to said parallel spaced supposition wherein said supports are normal to the surface of said screen.
7. A portable antenna structure including a screen reflector assembly and an array of dipole antenna elements arranged before said reflector assembly in the operating position, said screen reflector assembly comprising two screen reflectors arranged to fold together with the space therebetween less than the distance between said antenna elements and said reflector assembly in the operating position, supporting members attached to each of said dipole antenna elements, said supporting members being pivotally mounted at the ends thereof near said reflector assembly to permit said dipole elements and attached supporting members to be folded to lie flat alongside said screen reflectors to occupy a space less than that between the screen reflectors when folded in the non-operating position.
GEORGE A. KUMPF.
REFERENCES CITED The following references are of record in the file of this patent:
UNITED STATES PATENTS Number Name Date 1,612,939 Neitzel et al Jan. 4, 1927 1,684,009 Brown Sept. 11, 1928 2,073,085 Wells Mar. 9, 1937 2,082,347 Leib et a1 June 1, 1937 2,097,707 Tichenor Nov. 2, 1937 2,138,134 Beverage et a1. Nov. 29, 1938 2,160,053 Barbour May 30, 1939 2,270,314 Kraus Jan. 20, 1942 2,280,738 Bace Apr. 21, 1942 2,282,388 Zeh May 12, 1942 2,299,218 Fener Oct. 20, 1942 2,313,513 Brown Mar. 9, 1943 2,397,645 Brown Apr. 2, 1946 FOREIGN PATENTS Number Country Date 495,019 Great Britain Nov. 4, 1938