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Publication numberUS2714161 A
Publication typeGrant
Publication dateJul 26, 1955
Filing dateOct 12, 1951
Priority dateOct 12, 1951
Publication numberUS 2714161 A, US 2714161A, US-A-2714161, US2714161 A, US2714161A
InventorsArthur H Featherstun
Original AssigneeArthur H Featherstun
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Vibration arrester for multi-element antenna arrays such as used in television and f. m.
US 2714161 A
Abstract  available in
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Claims  available in
Description  (OCR text may contain errors)

July 1955 A. H. FEATHERSTUN ,1

VIBRATION ARRESTER FOR MULTI-ELEMENT ANTENNA ARRAYS SUCH AS USED IN TELEVISION AND F. M.

Filed Oct. 12. 1951 INVENTOR APTHUE H. F634 THEEJ TU/V,

United btates Patent VIBRATION STER FQR MULTI-ELEMENT ANTENNA ARRAYS SUCH AS USED IN TELE- VISION AND F. I /l.

Arthur H. Featherstun, Mount Vernon, Ill. Application October 12, U51, Serial No. 250,981 4 Claims. (Cl. 250-33) This invention relates to antenna structure, and more particularly to means for preventing excessive vibration of the elements of antennas of the type employed for television and frequency modulation reception.

A main object of the invention is to provide novel and improved means for damping the vibration of the elements of antennas, such as the elements employed in television and frequency modulation antennas, said means being very simple in construction, being easy to install, involving a minimum amount of modification of existing structures, and providing effective damping of the vibration which would otherwise occur in the elements, whereby damage and breakage of the elements are avoided.

A further object of the invention is to provide an improved vibration arresting means for the elements of antennas, such as television and frequency modulation antennas, said means involving inexpensive components, being adaptable for fabrication on the elements at the time of manufacture, or for clamping on existing antenna elements, and providing an effective arrangement for preventing excessive vibration of the elements, whereby bending and breakage to said elements is prevented and the etficiency of the antenna is maintained over long periods of time without requiring repair or servicing.

Further objects and advantages of the invention will become apparent from the following description and claims, and from the accompanying drawings, wherein:

Figure l is a perspective View of a television antenna provided with a vibration-damping means according to the present invention;

Figure 2 is an enlarged cross-sectional view taken on the line 2-2 of Figure l, and showing the specific structure involved in the vibration damping means;

Figure 3 is a side elevational view of the structure of Figure 2;

Figure 4 is a cross-sectional view taken on the line 4-4 of Figure 3;

Figure 5 is an end elevational view of the structure of Figures 2 and 3;

Figure 6 is a longitudinal cross-sectional view taken through a modified form of vibration-damping means according to the present invention, which may be employed on the elements of an existing antenna, or which may be optionally installed on the elements during the manufacture of the antenna;

Figure 7 is a side elevational view of a further modified form of vibration-damping means especially adapted to be installed on existing antennas and showing the manner of connection of the vibration-damping means to an element of an existing antenna;

Figure 8 is a cross-sectional view taken on the line 88 of Figure 7.

Referring to the drawings, and more particularly to Figures 1 to 5, 11 generally designates a television antenna structure comprising the vertical mast 12, the horizontal boom 13 clamped to the mast in the usual manner, the folded dipole 14 secured to one end of the 2,714,16l Patented July 26, 1955 boom 13 in the usual manner, and the horizontally extending, rod-like elements 15 secured to the boom 13. As shown in Figure 1, the elements 15 are secured rigidly at their mid-portions to the boom 13, and the respective ends of the elements are free. In the case of the conventional antenna structure, the elements 15 are free to vibrate under wind forces or other causes, and when the vibration occurs at a frequency close to the natural frequency of vibration of the element, the amplitude of the vibration may become so excessive as to cause the element to snap oif adjacent to its point of connection to the boom 13. In this manner, a great number of elements become broken and require replacement, especially where the antenna is mounted at a considerable elevation and is exposed to heavy wind forces.

The element 15 is usually formed of hollow, tubular stock, as shown in Figure 2, and in accordance with the present invention, the element is crimped at 16, 16, as well as at the end of the element, as shown at 17, t0 define a tubular housing element 18. Loosely mounted in the housing element 18 is a damping weight element 19, which may comprise a short length of heavy gauge, rubber-covered Wire, such as No. 6 gauge rubber-covered Wire, having the copper conductor portion 20 and the rubber sheath 21. The damping weight 19 may have a length of the order of one inch, and the length of housing element 18 may be of the order of two and one-half inches, whereby the damping weight 19 is freely movable longitudinaly in the housing element and is also freely movable to some degree in a direction at right angles to its axis.

Both ends of each element 15 are similarly provided with the vibration-arresting means, as above described, whereby when the element 15 tends to vibrate, the damping elements 19 in the housing portions 18 at the ends of the element shift in position and prevent the free portions of the element from vibrating at their natural resonant frequencies. Thus, the amplitudes of vibrations of the free portions of the element 15 are kept reasonably low, and the stresses produced in the element 15 as a result of such vibrations are kept below the values at which breakage of the element would occur.

Referring now to Figure 6, a modified form of vibration-damping means is disclosed comprising a hollow plug element 22 of plastic material or other similar durable material formed with a reduced hollow stem portion 23 having a longitudinal drain slot 30 and with a cavity 24 communicating with the stem portion 23 by a passage 25. Loosely positioned in the cavity 24 is a weighted ball 26 which is free to move longitudinally in the cavity 24, as well as in a direction transverse to the axis thereof. The reduced tubular portion 23 of the vibration arrester is secured in the end of the antenna element, shown at 15, and may be secured therein in any suitable manner, as by a tight frictional fit. The vibration-arresting means may be secured in the end of the element 15 either during the manufacture of the antenna, or after the antenna has been installed. The operation of the device is similar to the operation of the form of the invention disclosed in Figures 1 to 5, namely, when vibration of the free portions of the element 15 occur, the weight element 26 shifts its position in the cavity 24 and prevents the free portions of the element from vibrating at their natural resonant frequency.

In the form of the invention shown in Figures 7 and 8, a hollow plug element 22 having a reduced portion 23 is clamped to the end portion of an antenna element, shown at 35 and which is provided with opposed clamping channel elements 37, 37 engaged around the reduced portion 23' of the vibration arrester. Plug element 22' is formed with a longitudinal drain slot 30', as shown. A clamping bolt 38 is provided for exerting the required clamping pressure on the reduced portion 23 to rigidly secure the vibration-arresting device to the end portion of the horizontally extending antenna element 35. As in the previous embodiments of the invention, when the element 35 begins to vibrate, the weighted ball 26 inside the housing portion 22' shifts its position and prevents the element from vibrating continuously at its natural resonant frequency. This maintains the amplitude of vibration at a low value and prevents breakage of the element, as above described.

While certain specific embodiments of an improved vibration-arresting means for the free element portions of television and frequency modulation antennas have been disclosed in the foregoing description, it will he understood that various modifications within the spirit of the invention may occur to those skilled in the art. Therefore, it is intended that no limitations be placed on the invention except as defined by the scope of the appended claims.

What is claimed is:

1. In a multi-element antenna array, the combination of a horizon-tally extending element having at least one free end, and vibration damping means comprising a housing rigidly secured to said free end and having an internal cavity extending in. the same direction as said element, and a movable damping weight contained in said cavity, said Weight comprising a unitary body having a volume which occupies a substantial portion of the volume of said cavity but which is substantially smaller both longitudinally and transversely than said cavity,

whereby the weight is free to move both transversely and longitudinally in the cavity.

2. In a. multi-element antenna. array, the combination of a horizontally extending element having free ends, respective elongated housings rigidly secured to said free ends and having internal cavities extending in the same direction as said. element, and respective damping weights movably disposed in said cavities for free movement therein, each of said weights. comprising. a unitary body having a volume which. occupies. a substantial portion of the volume of itsv respective. cavity butwhich. is substantially smaller both longitudinally and transversely than said cavity, whereby the weights are free to move both transversely and longitudinally in the cavities.

3. In a multi-element antenna array of the character described, the combination of a horizontally extending boom, a horizontal element rigidly secured at its mid portion to said boom, respective tubular housings rigidly carried at the ends of said element and having internal cavities extending in the same direction as said element, and respective damping weights loosely disposed in said housings for free movement therein, each of said weights comprising a unitary body having a volume Which occupies a substantial portion of the volume of its respective cavity but which is substantially smaller both longitudinally and transversely than said cavity, whereby the weights are free to move both longitudinally and transversely in the cavities.

4. in a multi-element antenna array, the combination of a horizontally extending boom, 2. horizontal element rigidly secured at its mid portion to said boom, respective tubular housings rigidly carried at the ends of. said element and having internal cavities extending in the same direction as said element, and respective elongated damping weights loosely disposed in said housings for free movement therein, each Weight comprising a unitary body having a volume which occupies a substantial portion of the volume of its respective cavity but which is substantially smaller both longitudinally and transversely than said cavit whereby the weights are free to move both longitudinally and transversely in the cavities.

References Cited in the file of this patent UNITED STATES PATENTS 2,155,052 Byland' Apr. 18, 1939 2,195,041 Von- Schlippe' Mar. 26, 1940 2,302,670 Buchanan Nov. 24, 1942 2,462,961 Harker Mar. 1, 1949 2,586,043 Hodgson-et al Feb. 19, 1952 FOREIGN PATENTS 652,318 Great Britain Apr. 1 8-, 1951

Patent Citations
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US2155052 *Apr 12, 1937Apr 18, 1939Dresag A GMeans for destroying the energy of mass oscillations of solid bodies
US2195041 *Sep 5, 1936Mar 26, 1940Messerschmitt Boelkow BlohmMeans for damping oscillations
US2302670 *Oct 14, 1941Nov 24, 1942James A BuchananAccelerometer
US2462961 *Jan 24, 1945Mar 1, 1949United Aircraft CorpPropeller blade vibration absorber
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Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2866195 *Feb 23, 1954Dec 23, 1958Powlison Neil CTelevision receiving antenna
US3031046 *Jul 3, 1959Apr 24, 1962United Aircraft CorpSandwich structure
US3210765 *Jun 12, 1961Oct 5, 1965Collins Radio CoAntenna element damping device
US3277486 *Jun 12, 1962Oct 4, 1966Kuebler Manfred FMethod and means for damping nutation in a satellite
US3419871 *Oct 23, 1965Dec 31, 1968Comm Structures IncAntenna feedhorn support structure
US3612222 *Feb 18, 1970Oct 12, 1971Kearney National IncPole damping system
US3826340 *Sep 19, 1973Jul 30, 1974H BrokawVibration damper for slender vertical structures
US3911199 *Apr 26, 1974Oct 7, 1975Westinghouse Electric CorpSeismic motion-damper for upstanding electrical equipment
US4472024 *Jan 7, 1982Sep 18, 1984Olympus Optical Co. Ltd.Apparatus for driving objective lens
US4953672 *Mar 31, 1989Sep 4, 1990Nippon Cable System, Inc.Control cable system with device for reducing vibration
US6348899May 24, 2000Feb 19, 2002David M. BergsteinAntenna mast adapter
US6435323Dec 18, 2000Aug 20, 2002Texas Tech UniversityDistributed aerodynamic and mechanical damping of cables with active smart control
US6439359 *Dec 8, 1998Aug 27, 2002Tokai Rubber Industries, Ltd.Damper for vehicles
US6494444Feb 27, 2001Dec 17, 2002Tokai Rubber Industries, Ltd.Vibration damping device for vehicles
US6536566Feb 27, 2001Mar 25, 2003Tokai Rubber Industries, Ltd.Vibration-damping device for vehicles
US6554112Aug 8, 2001Apr 29, 2003Tokai Rubber Industries, Ltd.Vibration-damping device for vehicle
US6598718Mar 19, 2002Jul 29, 2003Tokai Rubber Industries, Ltd.Vibration damping device having a flock coating
US6641119Dec 22, 2001Nov 4, 2003Tokai Rubber Industries, Ltd.Vibration-damping device having independent mass member
US6705440Apr 30, 2002Mar 16, 2004Texas Tech UniversityCable stay damper band and method of use for reduction of fluid induced cable vibrations
US6719108Mar 13, 2001Apr 13, 2004Tokai Rubber Industries, Ltd.Virbration damping device for vehicles
US6722481Sep 24, 2002Apr 20, 2004Tokai Rubber Industries, Ltd.Vibration-damping device
US6854721Feb 13, 2002Feb 15, 2005Tokai Rubber Industries, Ltd.Vibration-damping device
US6991077Sep 26, 2002Jan 31, 2006Tokai Rubber Industries, Ltd.Vibration damping device
US7232017 *Apr 1, 2004Jun 19, 2007Kearney-National Inc.Pole vibration damping assembly and method
US7267740May 10, 2005Sep 11, 2007Tokai Rubber Industries, Ltd.Vibration-damping device for vehicles and method of manufacturing the same
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EP1132644A2 *Feb 26, 2001Sep 12, 2001Tokai Rubber Industries, Ltd.Vibration damping device for vehicles
Classifications
U.S. Classification188/378, 343/DIG.200, 343/904, 343/803, 343/819, 174/42
International ClassificationH01Q1/20
Cooperative ClassificationY10S343/02, H01Q1/20
European ClassificationH01Q1/20