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Publication numberUS3699585 A
Publication typeGrant
Publication dateOct 17, 1972
Filing dateDec 17, 1970
Priority dateDec 17, 1970
Publication numberUS 3699585 A, US 3699585A, US-A-3699585, US3699585 A, US3699585A
InventorsMorrison Adrian O
Original AssigneeNorth American Rockwell
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Collapsible helical antenna
US 3699585 A
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Description  (OCR text may contain errors)

United States Patent Morrison [54] COLLAPSIBLE HELICAL ANTENNA [72] Inventor: Adrian O. Morrison, Tustin, Calif.

[73] Assignee: North American Rockwell Corporation 22 Filed: Dec. 17,1970

[21] Appl.No.:99,'172

[52] US. Cl ..343/880, 343/895 [51] Int. Cl. ..H01q 1/36 [58] Field of Search ..343/895, 880

[56] References Cited UNITED STATES PATENTS 3,524,193 8/1970 Auletta ..343/895 2,613,319 10/1952 Lisbin et al. ..343/823 3,541,568 11/1970 Lowenhar ..343/877 FOREIGN PATENTS OR APPLICATIONS 810,325 12/1936 France ..343/895 51 Oct. 17,1972

Primary Eicaminer--Eli Lieberman Attorney-L. Lee l-lumphries, Charles F. Dischler and Dominick Nardelli [5 7] ABSTRACT A collapsible helical antenna formed of an extensible boom made of preferably two coiled flat steel ribbons which, when uncoiled, become tubular one inside the other and formed of a helical conductor that is suspended coaxially from the boom by a plurality of rings disposed around the boom and tied together by flexible members and by tensioned members extending from the rings to the helical conductor so that, as the boom is extended, the rings slide along the boom to become separated a distance determined by the flexible members but the helical wire is still maintained coaxial with the boom.

11 Claims, 5 Drawing Figures PATENIED [IN 1 7 I972 3 Sheets-Sheet 1 INVENTOR. ADRIAN O. MORRISON ATTOP'VEY pmmgnum 11 I972 3 Sheets-Sheet 5 INVENTOR.

ADRIAN 0. MORRISON ATTORNEY COLLAPSIBLE HELICAL ANTENNA FIELD OF INVENTION This invention relates to an extensible antenna and,

more particularly, to an extensible antenna of the helical type.

BACKGROUND OF THE INVENTION OBIECTS OF THE INVENTION An object of this invention is to provide a helical antenna which is light in weight and which is collapsible from its operative or extended position for ease of portability.

Another object of this invention is to accomplish the foregoing economically and with sufficient dimensional accuracy and structural rigidity to meet the stringent requirements imposed on helical antennas.

Another object of this invention is to provide a boom which is extensible and still provides the maximum possible rigidity.

These and other objects and features of advantage will become more apparent after reading the following description of the preferred embodiment of the invention taken together with the drawings.

BRIEF DESCRIPTION OF THE VIEWS AND DRAWINGS FIG. 1 is an elevation of a collapsible helical antenna in the extended position and incorporating the features of the invention;

FIG. 2 is an enlarged elevation view of a few of the turns of the helix;

FIG. 3 is an enlarged elevation and partial section of the antenna in FIG. 1 in the collapsed position;

FIG. 4 is an end elevation view of the antenna taken on line 44 in FIG. 3 and in the direction of the arrows; and

FIG. 5 is a plan view in section of a portion of the antenna taken substantially on line 55 in FIG. 3 and in the direction of the arrows.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings and to FIG. 1, in particular, a collapsible helical antenna is shown in the extended position and having a boom 11 supported by a post 12 from a suitable structure 13. Around the boom 11 is disposed a helical conductor 14 having a coupling wire 16 extending from the helical conductor 16 to the structure 13. The conductor 14 is suspended coaxially from the boom by insulating tension members to be described more fully hereinafter. The coupling wire 16 is supported from the post 12 by one or more insulators l7.

Referring to FIGS. 2, 3, and 4, the insulating tension members mentioned above are more clearly illustrated. On boom 11 are disposed a plurality of rings 21a, 21b, and 210. Each one of the rings 21a, 21b, and 21c are preferably made of nylon which is a long chain polymeric amide having re-occurring amide groups CONI-I as an integral part of the main polymer chain and which has the inherent property of being capable of sliding along metallic surface under extreme weathering conditions for reasons that will become apparent hereinafter. All the rings,21a, 21b, 21c, are connected one to the other by nylon flexible threads 22 all of equal length. The ends of threads 22 are suitably fixed to the rings as shown by suitable means. The threads 22 are disposed on opposite sides of the boom 11. The thread segments between adjacentrings are equal so that the rings may be equally spaced along the boom. All the rings 21a have attached thereto in a suitable manner nylon threads 23 at a point 23a on the respective ring that is rotated from the point of attachment of threads 22. Threads 23 connectto points 14a on the helical conductor 14 disposed radially outward from the points 23a and are of equal length. The threads 23 are arranged in a zig-zag arrangement wherein two segments of threads 23 are attached at the same point 14a and at the same point 23a. Rings 21b are attached to the conductor 14 by nylon threads 24. However, attachment points 24a (FIG. 3) for threads 24 at the rings 21b and attachment points 14b(FIG. 4) at the conductors 14 are rotated from the points of attachment points 14a and 23a of threads 23. Also, rings 210 are attached to the conductor by nylon threads 25. However, the attachment points 25a (FIG. 4) of threads 25 at rings 21c and attachment points 14c at the conductor 14 are rotated 120 from the points 14a and 23 a of threads 23 and also points 14b and 24a of threads 24. Thus, the helical conductor 14 is supported rigidly coaxially with the boom 11 because all nylon threads 23, 24, and 25 are of equal length.

Since the rings 21a, 21b, and 216 are capable of sliding axially along the boom 11, the helical conductor 14 is made to collapse to a position as shown in FIG. 3 wherein the rings 21a, 21b, and 21c touch each other. Then, naturally, the segments of the threads 22 form loose loops as shown. The boom 11 is made of two relatively narrow, relatively long metallic strips 31 and 32 as shown in FIGS. 4 and 5. Strips 31 and 32 are made of, for example, beryllium copper sheets having a thickness of a few thousandths of an inch and have been heat treated in a standard manner as to cause each strip to assume a tubular shape. Due to their fle xibility, the sheets 31 and 32 can be rolled upon spools such as spools 33 and 34, respectively. The spools 33 and 34 are journalled mounted within a suitable enclosure 36. The right end of enclosure 36, as viewed in FIG. 3, tapers down to a circular opening 37 through which the assembled boom 11 passes. The strips 31 and 32 are arranged so, as they unwind from the respective spools, strip 31 assumes its tubular shape within the tubular shape assumed by strip 32. In addition, the respective edges meet each other at positions that are on opposite sides of the boom 11 as shown in FIG. 4. The outer strip 31 can be made to assume a free diameter that is slightly smaller than the external diameter assumed by the inner strip 32. This causes the two strips to come into more intimate contact making a more rigid boom. The post 12 is fixed to the enclosure 36 and, more specifically, to the lower section thereon as shown in FIG. 3. The boom 11 may be extended or retrieved by rotating one of the spools, for example spools 34, by suitable electric motor 41 (FIG. 3) mounted below the enclosure. The left ends of the strips are bonded together so that, as spool 34 rotates, both strips are extended or retracted together. As an alternative, the spools 33 and 34 may be geared together in a suitable manner. To cause the helical conductors to move with boom 11, the exterior ring 21a at the extreme left end as viewed in FIG. 3 is bonded in a suitable manner to the outer strip 31. Thus, both the boom and helix can be extended or retracted as required.

Although the preferred embodiment has been described, one understands that the description is made only by way of example and not as a limitation to the scope of the invention. The scope, therefore, is limited to the accompanying claims.

What is claimed is: 1. A collapsible, helical antenna comprising: a boom; a helical conductor disposed around said boom; a plurality of rings disposed on said boom and in sliding relation therewith; first tension elements extending from said rings to said helical conductor to hold said conductor coaxial to said boom; and flexible elements disposed to extend between adjacent ones of said rings for determining the maximum pitch of said helical conductor. 2. The antenna of claim 1 wherein: said boom is extendable and retractable and comprises at least one extendable resilient strip that is so fabricated so as to tend to form into an elongated tube, and when unrestrained has its longitudinal axis lying parallel to the longitudinal centerline of the strip. 3. The antenna of claim 2 wherein: said boom further includes another one of said resilient strip; and said other one of said strips being disposed within the tubular form of said one strip when in the unrestrained position. 4. The antenna of claim 3 wherein: said boom is further defined that the longitudinal edges of said one strip is disposed opposite the longitudinal edges of said other strip when said strips are in their tubular form; and

separate spools are provided for each strip to be rolled onto when said boom is retracted.

5. The antenna of claim 4 wherein:

the free ends of said strips are bonded together; and

one of said rings that is disposed nearest the free ends is bonded to said one strip substantially adjacent the free end.

6. The antenna of claim 5 wherein:

two of said tension elements have one end respectively bonded at the same point on one of said rings; and

two of said tension elements have the other end respectively bonded to the same point on said conductor to form a zig-zag configuration when said antenna is extending.

7. The antenna of claim 1 wherein: said boom 15 extendable and retractable and comprises at least one extendable narrow resilient strip that is so fabricated so as to tend to form into an elongated tube and when unrestrained .has its longitudinal axis lying parallel to the longitudinal centerline of the strip.

8. The antenna of claim 7 wherein:

said boom further includes another one of said narrow, resilient strips; and

said other one of said strips being disposed within the tubular form of said one strip when in the unrestrained position.

9. The antenna of claim 8 wherein:

said boom is further defined that the longitudinal edges of said one strip is disposed opposite the longitudinal edges of said other strip when said strips are in their tubular form; and

separate spools are provided for each strip to be rolled onto when said boom is retracted.

10. The antenna of claim 9 wherein:

the free end of said strips are bonded together; and

one of said rings, that is disposed nearest said free end, is bonded to said one strip substantially adjacent the free end thereof.

11. The antenna of claim 10 wherein:

two of said tension elements have one end respectively bonded at the same point on one of said rings; and

two of said tension elements have the other end respectively bonded to the same point on said conductor to form a zig-zag configuration when said antenna is extended.

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3836979 *Dec 14, 1973Sep 17, 1974Trw IncLightweight deployable helical antenna
US3975581 *Sep 24, 1973Aug 17, 1976Herman LowenharTransmission lines using tubular extendible structures
US4068238 *May 13, 1976Jan 10, 1978Trw Inc.Elastic strain energy deployable helical antenna
US4096459 *Aug 11, 1976Jun 20, 1978Herman LowenharTwo wire transmission line using tubular extendible structures
US4780727 *Jun 18, 1987Oct 25, 1988Andrew CorporationCollapsible bifilar helical antenna
US5146235 *Dec 13, 1990Sep 8, 1992Akg Akustische U. Kino-Gerate Gesellschaft M.B.H.Helical uhf transmitting and/or receiving antenna
US5612707 *Apr 23, 1993Mar 18, 1997Industrial Research LimitedSteerable beam helix antenna
US5909197 *Apr 4, 1997Jun 1, 1999Aec-Able Engineering Co., Inc.Deployable helical antenna stowage in a compact retracted configuration
US8490511Aug 22, 2007Jul 23, 2013Takashi SaitoManipulator mechanism
EP2075100A1 *Aug 22, 2007Jul 1, 2009Takashi SaitoManipulator mechanism
Classifications
U.S. Classification343/880, 343/895
International ClassificationH01Q11/08, H01Q11/00
Cooperative ClassificationH01Q11/086
European ClassificationH01Q11/08C