COLLAPSIBLE HELICAL ANTENNA

• US 3,699,585 A
• Filed: 12/17/1970
• Issued: 10/17/1972
• Est. Priority Date: 12/17/1970
• Status: Expired due to Term

• Current Assignee: Adrian O. Morrison
• Original Assignee: Adrian O. Morrison
• Inventors: Morrison, Adrian O.
• Primary Examiner(s): Lieberman, Eli
• Application Number:
  US05/099,172
• Time in Patent Office: 670 Days
• Field of Search: 343/895,880
• US Class Current: 343/880
• CPC Class Codes: H01Q 11/086 collapsible

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.

Claims

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 is 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.