US 3268897 A
Description (OCR text may contain errors)
Aug. 23, 1966 R. R. LINK CITIZEN'S BAND RADIO ANTENNA Filed Sept. 16, 1964 INVENTOR.
RALPH R. LINK United States Patent "ice 3,268,897 CITIZENS BAND RADID ANTENNA Ralph R. Link, 2113 W. 23rd St, Little Rock, Ark. Filed Sept. 16, 1964, Ser. No. 396,907 4 Claims. (Cl. 343713) This invention relates generally to radio antennas, and more specifically to a Citizen's band antenna for mounting on the top of a vehicle.
It is well known that when sending or receiving radio signals from a vehicle, the power of such a signal is greatly influenced by the position of the aerial in relation to the vehicle and the direction from which the signal is being received or sent. Ideally therefore the antenna should be mounted on the top of the vehicle so as to be unaifected by the vehicle itself. My invention is directed to the provision of an antenna which can receive signals from all directions with equal magnitude and greatly increased fidelity.
It is therefore a primary object of this invention to construct a radio antenna for vehicles suitable for operation on the Citizens wave band which may be mounted on the top of a vehicle without cutting mounting holes and thereby damaging the vehicle roof.
It is a further object of this invention to provide an improved Citizens band radio antenna which is completely insulated from the body of the vehicle and which is placed remotely from the ignition system so as to establish minimum interference therefrom.
It is yet a further object of this invention to provide a radio antenna for vehicles which operates with equal efficiency in all directions, and which is of robust construction to give an improved performance without causing obstruction during the normal use of the vehicle.
Further objects and advantages of this invention will become apparent from the following more detailed description of a preferred embodiment thereof, taken in conjunction with the attached drawings wherein:
FIG. 1 is a perspective view of the radio antenna constructed in accordance with my invention.
FIG. 2 is a perspective fragmentary view showing the top of a vehicle with the antenna mounted thereon.
FIG. 3 is a cross sectional side elevation of the central ball antenna and associated loading coil balanced for the Citizens band.
FIG. 4 is a cross sectional plan view taken along the lines 44 of FIG. 3.
Similar reference characters indicate corresponding parts throughout the several views in the drawings.
Referring now to the drawings in detail, the numeral 5 represents the roof of a vehicle on which the antenna is to be mounted. The antenna is constructed from a square aluminum plate 6 having a preferred dimension of twelve inches by inch thick. Four cylindrical stand off insulators 7 are secured to project beneath the four corners of the plate 6 and the outer ends of these insulators are capped with suction cups 8 which should be in the order of two inches in diameter. Four radials 9 are mounted to project one from each side of the plate 6 so as to be oriented at ninety degrees with respect to each other. The radials are /8 inch in diameter and 18 inches long. The radials are adjustably secured to the top of the plate by short straps 10' which extend through holes formed through the plate and are 3,268,897 Patented August 23, 1966 selectively tightened by a nut on the underside of the plate such that the degree of projection can be varied so as to balance in resonance with the transmitter. Two straps 10 are recommended to secure each of the radials.
Mounted centrally of the plate 6 is a square plastic insulator 11 having a recommended dimension of four inches by /2 inch thick. A copper cap 12 is secured to the end of a threaded stud 13 which extends through a central hole 14 formed through the insulator 11 and the plate 6. The lower end of the stud protrudes beneath the plate 6 and terminates with a threaded plug 15 which is secured by screws 16 to the underside of the plate. Projecting upwardly from the copper cap 12 is a plastic tube 17 which forms an insulated coil form around which a loading coil 18 is wound in balance for 27 megacycles Citizen band. The upper end of the tube is capped by a similar copper cap 19 and the ends of the loading coil 18 are suitably secured to the two caps. Mounted on the top of the upper cap 19 is a chrome plated copper sphere 20 having a threaded boss 21 projecting therefrom to engage in a central hole formed through the cap. This sphere is preferably about five inches in diameter and acts as an energy collector having a large surface area to aid in picking up weak signals and to generally improve reception. A plastic tube 22 extends between the two copper caps 12 and 19 and performs as a weather shield for the coil. An antenna cable 23 terminates with a threaded plug 24 for engagement over the plug 15 and the cable extends from this point through any window of the vehicle to connect with the transmitter.
The many advantages afforded by a top mounted antenna have thus been achieved without cutting holes in the vehicle top, and the design of this antenna greatly improves the operating efficiency over other antennas presently known.
Having described the invention in a preferred form, it will be appreciated that some modifications may be made to the precise configuration, without departing from the scope or spirit of the invention, as defined by the following claims.
1. A radio antenna for mounting on the top of a vehicle, and comprising, a rectangular plate, tubular insulators secured to the underside of the plate, suction cups mounted on the end of the tubular insulators for securing the plate to the top of a vehicle, a flat insulator mounted centrally on top of the plate, a copper cap having a stud projecting downwardly through a hole formed through the flat insulator and the plate, a plastic loading coil tube upstanding from the copper cap, a second copper cap secured to the other end of the loading coil tube, a loading coil wound around the loading coil tube and connected at its ends to the caps, a copper sphere mounted on the top of the "second copper cap, a weather sleeve extending between and over both caps to protect the loading coil, an antenna cable removably connected to the stud, and four antenna radials mounted to the top of the plate to project norm-ally from each side thereof.
2. A radio antenna according to claim 1, wherein said radials are adjustable in length and wherein the loading coil is balanced for the 27 megacycle band.
3. A radio antenna according to claim 1, wherein the tubular insulators are secured beneath each corner of the plate, and wherein the radials projecting from opposite sides of the plate are in a spaced and panallel relationship.
4. A radio antenna for mounting on top of a vehicle, comprising, a rectangular aluminum plate, four tubular insulators secured beneath the corners of the plate, suction cups removably connecting the ends of the tubular insulators to the top of the vehicle, four radials adjustably mounted at one end to the top of the plate and projecting normally from the four sides thereof, a flat square insulator mounted on top of the plate, a copper cap, a stud extending from the cap through a hole formed through the plate and the square insulator, a plastic loading coil tube received by the cap and projecting thereabove, a second copper cap mounted on the other end of the loading coil tube, a loading coil wound around the loading coil tube and connected at each end to the caps, a copper sphere mounted on the top of the second copper cap, a weather sleeve extending between and over both caps to protect the loading coil, and an antenna cable secured to the end of the stud.
No references cited.
HERMAN KARL SAALBACH, Primary Examiner.
R. F. HUNT, Assistant Examiner.