US2803010A

US2803010A - Folding outdoor antenna

Info

Publication number: US2803010A
Application number: US436074A
Authority: US
Inventors: Spirt Milton; Goldman Jerome
Original assignee: SPIRT
Current assignee: SPIRT
Priority date: 1954-06-11
Filing date: 1954-06-11
Publication date: 1957-08-13
Anticipated expiration: 1974-08-13

Description

Aug. 13, 1957 M. sPlRT ETiAL FOLDING ouTnooR ANTENNA 2 Sheets-Sheet l Filed June ll. 1954 .llili s .y Z .M W H M f N n. @AN A N@ Z 0f a k A Y www@ X@ B .ld/m\\\ u N., INMMWH NAN, mM l1 ..mrfa l N. Aw ,(iw NW Mmm u Nm Aug- 13, 1957 M. sPlRT ET AL 2,803,010

FOLDING OUTDOOR ANTENNA United States 2,803,010 Forum@ oUrDoon ANTENNA Milton Spirt, Jamaica, andlierome Goldman, New York, N. Y.; said Goldman assigner to said Spirt The present invention relates to Aantennae for the reception of high frequency signals, and more particularly to signals lying in two distinct spaced frequency bands, such as channels 2 to 13 of the present frequency allocation for television channels. f

An object of the invention is to provide a unitary antenna structure comprising 'elements dimensioned for resonance in two separate frequencyranges. A further object of the invention -is the provision of a parasitic rellectt'srrelementY for each frequency band, each reector being'positioned for cooperation with the signal receiving elements for one of the bands of signal frequencies.

Still another object of the invention is the provision of a pair of high frequency signal receiving elements forming a generally U-shaped configuration and having arm portions connected to a pair of low frequency signalreceiving elements in `such manner that a common transmission line may be connected to both pairs of signal receiving elements at a single pair of lantenna output terminals. i

Another object of the invention is the provision of a mid-band parasitic resonator for the higher frequency atent band disposed inclose proximity tothe-high frequency v signal receiving elements for improving the efficiency of reception of the high frequency signals.Y v

A further object of the invention is the provision of an antenna of this character which may be folded for shipment and readily unfolded for installation, the several antenna elements being securely positioned in either the folded or unfolded position. i l

Other and further objects, features and advantages of the invention will becomeV apparent upon reading thefollowing specification together with the accompanying drawing forming a parthereof.

Referring to the drawing:

Fig. l Vis a front view in elevation of an antenna embodying the invention `mounted upon a vertical pipe support;

Fig. 2 is a side elevational view of the antenna of Fig. 1 in folded condition;

Fig. 3 is a plan of the folded antenna shown in Fig. 2;

Fig. 4 is a perspective view of an unfolded antenna mounted in operating position on a vertical pipe support;

Fig. 5 is 'an' enlarged fragmentary sectional view in elevation taken along the line 5-5 of Fig. 4, looking in the direction of the arrows;

Fig. 6 is an enlarged fragmentary perspective view showing an inner fend portion of one of the low frequency signal receiving elements locked in a laterally extending position as shown in Fig. 4;

Fig. 7 is an enlarged fragmentary sectional view in side elevation taken along the line 7-7 of Fig. 4, looking in the direction of the arrows;

Fig. 8 is an enlarged fragmentary sectional view in front elevation taken along the line 8-8 of Fig. 7, looking in the direction of the arrows.

.ice

tinsulatingV plate 19 by the

rivets

17 and 18, but the connections are relatively tight and produce frictional forces which oppose this pivotal movement, such pivotal movement being required only when folding or unfolding the antenna. In ythis manner, any looseness which might c ause undesirable relative movement of the antenna elements is avoided. A certain residual amount of resiliency :in-thevcrimpe'd flattened ends at 15 and 16 is advantageously provided to maintain this tight pivotal mechanical connection, notwithstanding dimensional variations accompanying changes in ambient temperature.

'The insulating plate 19 is Xedly secured to the front end of a central supporting member 20 by rivets 21. Intermediate the ends of central supporting member 20 there is provided a supporting clamp comprising a U- bolty 22 (Figs. 3 'and 4) having threaded leg portions which pass freely through apertures formed in central supportingl member 20 and-through corresponding apertures formed in a ybearing plate 23. The U-bolt 22 secures the central supporting member 2i) to an upright supporting pipe 24 (Fig. 4) by tightening nuts 22u on the threaded legs of the U-bolt 22, thereby gripping pipe 24 between the closed end of U-bolt 22 and bearing plate 23.

A reflector consisting of laterally extending reflector elements 2S and 26 (Fig. 4) is provided behind the low frequency dipole kelements 11 and 12. The length of each low

frequency reflector element

25, 26 and each one-quarter of a wavelength behind the lower frequency l ban'dreceiving dipoles 11, 12 at the center frequency of `the low frequency band.

`The

reflector elements

25 and 26 are secured to a rear supporting plate 27 formed of electrically conductive material, being pivotally secured to supporting plate 27 by

rivets

30 and 31, respectively. Rivets 3i) and 31 provide pivotal and frictional connections as described above for rivets 17 and 1S which secure dipole elements 11 and V12 to the upper insulating plate 19. Rear supporting plate 27 is fixedly secured to the rear end of central supporting member 26 by a'pair of rivets 32 and 33.

A pair of

coupling elements

35 and 36 extend laterally outwardly from a lower insulating plate 37 disposed below the upper insulating plate 19. The

coupling elements

35 and 36 are aligned andl extend horizontally outwardly from the lower insulating plate 37 with inner portions which are generally parallel to the dipole elements 11 and 12. They then curve smoothly upwardly in a symmetrical manner to form relatively short vertically extending outer end portions 39 and 40 which extend toward and are connected to the dipole elements 11 and 12, respectively, intermediate the ends of each dipole element and inwardly of its midpoint. As shown in Fig. 5, the upwardly extending end portion 39 of coupling element 35 is connected to dipole element 11 by a strap 41 which is secured at its upper end by a bent tongue 42 whichprojects through-a cooperating slot formed in the flattened upper end 43 of coupling member 35. The strap 41 is permanently secured to flattened upper end 43 by a rivet 44, thus securely other dipole 'element 12..

At their adjacent inner ends, the

coupling elements

35 and 36 are connected to the under side of lower insulating plate 37 by

rivets

45 and 46, respectively, which provide both a pivotal and a frictional connection as described above for dipole elements v11 and 12.

The inner end portions of

coupling elements

35 and 36 are attened and bent downwardly, inwardly of

rivets

45 and 46 to provide vertical downwardly extending line terminal ears 47 and 4S (Fig. 8). The terminal ears 47 and 48 are shown provided with binding post terminals comprising bolts and wing nuts 49 and 50 to which a transmission line 51 is shown connected, -the transmission line 51 extending to a receiver or other signal utilization device (not shown).

The dipole elements 11 and 12 are dimensioned to be resonant to provide signal lsensitivity at a frequency within a lirst frequency band which, in practice, will be the range of channels 2 Ito 6. The

coupling elements

35 and 36 are dimensioned to be resonant to provide signal sensitivity at a frequency within a second and higher frequency band, the dipole elements 11 and 12 being relatively ineffective at these higher frequencies. In practice, the second frequency band will ordinarily cover the range of channels 7 to 13. The transmission line 51 is thus connected to the dipolt elements 11 and 12 through the

coupling elements

35 and 36 which are relatively ineffective at the resonant frequency of dipole elements 11 and 12.

The lower insulating plate 37 is connected to the forward end of central supporting member 20 by means of a C-shaped bracket 52 (Fig.'7). The upper end of C- shaped bracket 52 is xedly secured to the forward end of central supporting member 20 by means of rivets 21 together with upper insulating plate 19. The lower end of C-shaped bracket 52 is rearwardly directed and lower insulating plate 37 is xedly secured thereto by rivets 53, so that the upper and

lower insulating plates

19 and 37 are iixedly held in vertically spaced relationship with respect to each other at the forward end of central supporting member 2t).

A vertically adjustable L-shaped bracket designated generally as 54 is secured to C-shaped bracket 52 by a bolt 55 and wing nut 56. Bolt 55 passes through a vertically elongated slot 57 formed in the vertical upwardly extending leg S of L-shaped bracket 54. The lower horizontally extending leg 59 of L-shaped bracket 54 has an electrically conductive supporting plate 60 iixedly secured l thereto by rivets 61. Extending laterally outwardly from supporting plate 60 are parasitic resonator '

elements

62 and 62 pivotally and frictionally secured to supporting I plate 60 by rivets 63 and 64, respectively.

The

parasitic resonator

62, 62 is resonant at around the mid-frequency of the higher frequency band. The adjustable coupling provided by the L-shaped bracket 54 permits the

parasitic resonator

62, 62 to be moved toward or away from the horizontal portions of the

coupling elements

35 and 36 to vary the tuning to a limited extent within the higher frequency band. The

parasitic resonator

62, 62 serves to sharpen the resonance response characteristic of the

coupling elements

35 and 36 thereby increasing their effective signal sensitivity in the higher band and reducing any tendency which they might otherwise have to interfere with the connection therethrough to the dipole elements 11 and 12 at frequencies in the lower band. Additionally, the

parasitic resonator

62, 62 may be adjusted to be parallel to

coupling elements

35 and 36.

Disposed transversely of central supporting member at an appropriate distance behind

resonator

62, 62 is a parasitic reiiector member 65 for the higher frequency y band. Reector member 65 is upwardly curved intermerelatively immobile with respect to the dipole elements.

i pivotal movement.

to 73 are turnedto the positions lshown in Fig. 3.

diate its ends at 66 Ato pass over central supporting member 20 and prevent reector member 65 from turning out of the position shown in Fig. 4. Reflector member is secured to central supporting member 20 by a bolt and wing nut fastening device 67. Reflector member 65 may be turned to overlie central supporting member 20, as shown in Fig. 3, when the antenna is folded for shipment. Fastening device 67 is loosened and then tightened again for this purpose.

The antenna may be shipped in a folded condition, as shown in Figs. 2 4and 3, and unfolded for installation in the laterally extended condition shown in Figs. 1 and 4. Clamping devices are provided which hold the antenna in the folded condition for shipment and which lock it in the unfolded condition for permanent or temporary installation, as desired. The clamping devices comprise six clamp members 70 to 75, each held by a cooperating bolt and wing nut unit 76 to 81, respectively. Each clamp member comprises an apertured fiat portion which is held against one of the three

plates

19, 27 or 60 by one of the bolt and wing nut units 76 to 81 which passes through the apertured -flat portion of the clamp member and a corresponding aperture in one of the plates.` Each of the clamp members 70 to 75, further comprises an integrally formed Ushaped portion which embraces one of the antenna elements hold ing it pressed against one of the plates and locked against In Fig. 4, clamp member 70 and wing nut unit 76 hold dipole element 11 locked in its laterally extended position.

. As shown on an enlarged scale in Fig. 6, clamp member 71 and wing nut unit 77 hold dipole element 12 similarly locked in its laterally extended position. Clamp members 72 and 73 with their associated wing nut units 78 and 79 lock the low

frequency reflector elements

25 and 26, re-

- spectively, each in the laterally extended position@ Resonator elements 61 and 62 are locked in the laterally extended position by clamp members 74 andf75 and wing nut units and 81. No locking is shown for

coupling elements

35 and 36, since these elements are permanently clamped to dipole elements 11 and 12 and are thus held In the folded condition, the four clamp members 70 The low frequency dipole and reflector elements 11, 12 and '25, 26 are folded toward each other, generally parallel to the central supporting member 20. Clamp member .70, 76 holds reflector element 25 in the folded position instead of dipole element 11 in the laterally extended position.

Clamp member

71, 77 holds reflector element 26 in the folded position instead of dipole element 12 in l the laterally extended position.

, position, the elementsof resonator 61, 62 being sufficiently short so that they are held by the frictional pivoting action of rivets 63 and 64 without the need for locking. Coupling

members

35 and 36 are held in the folded position by their rigid connections to dipole elements 11 and 12, respectively.

It will be apparent to those skilled in the art that many changes and modifications may be made in the specific embodiment of the invention herein illustratively shown and described without departing from the scope of the invention as defined in the appended claims.

What is claimed is: Y

l. An antenna of the class described, comprising: a pair of aligned laterally extending dipole elements resonant to provide signal sensitivity at a frequency within a first frequency band; a pair of aligned laterally extending coupling elements each comprising lan inner portion extending generally parallel to one of said dipole elements and an outer end portion extending toward said dipole element and connected thereto intermediate the ends of and inwardly of the midpoint of said dipole element, said coupling elements being resonant to provide signal sensitivity at a frequency within a second frequency band at which said dipole elements are relatively ineffective and comprising frequencies appreciably higher than the frequencies of said first frequency band, and means for connecting a transmission line to said dipole elements through adjacent inner end portions of said coupling elements.

2. An antenna according to claim l, further comprising parasitic resonator means resonant within said second frequency band and disposed in proximity to and parallel to said inner portions of said coupling elements for increasing the sharpness of resonance thereof.

3. An antenna according to claim 2, further comprising adjustment means for varying the spacing between said parasitic resonator means and said parallel portions of said coupling elements.

4. An antenna according to claim l, further comprising reflector means for said dipole elements disposed rearwardly thereof; further reflector means for said coupling elements disposed rearwardly thereof; and common supporting means for said dipole elements, said coupling elements and both of said reflector means.

5. An antenna according to claim 4, further comprising parasitic resonator means carried by said common supporting means, said parasitic resonator means being resonant within said second frequency band and disposed in proximity to and parallel to said inner portions of said coupling elements for increasing the sharpness of resonance thereof.

6. An antenna according to claim 5, further comprising adjacent means for varying the spacing between said parasitic resonator means and said parallel portions of said coupling elements.

7. An antenna of the class described, comprising: elongated central forwardly and rearwardly extending supporting means; forward supporting means formed of insulating material and carried by said central supporting means; a pair of dipole elements pivotally secured to said forward supporting means and movable between laterally outwardly extending operative positions and folded positions adjacent to and generally parallel to said central supporting means; rear supporting means carried by said central supporting means; a pair of electrically interconnected reflector elements pivotally secured to said rear supporting means and movable between laterally outwardly extending operative positions and folded positions `adjacent to and generally parallel to said central supporting means; a pair of securing members carried by said forward supporting means and selectively engageable with said dipole elements to lock said dipole elements in their operative positions and with said reflector elements to lock said reflector elements in their folded positions; and a further pair of securing members carried by said rear supporting means and selectively engageable with said reflector elements to lock said reflector elements in their operative positions or with said dipole elements to lock said dipole elements in their folded positions.

8. An antenna according to claim 7, in which each of said securing member comprises a clamping member having a flat portion engageable with the particular supporting means by which it is carried and a U-shaped portion adapted to embrace a longitudinal portion of one of the antenna elements and press said portion of said antenna element into engagement with one of said supporting means for locking said antenna element against said pivotal movement, each of said securing members further comprising fastening means engaging said at portion of` said clamping member for drawing said flat portion into engagement with said particular supporting means and pressing said longitudinal portion of said antenna element thereagainst.

9. An antenna according to claim 8, in which said fastening means comprises two mutually engaging threaded members.

References Cited in the file of this patent UNITED STATES PATENTS 2,465,331 Resnick Mar. 22, 1949 2,492,529 Kaplan Dec. 27, 1949 2,494,665 Marshall Jan. 17, 1950 OTHER REFERENCES Nelson: Television Antennas, 2nd edition, 1951; Howard W. Sams Co., Inc., Indianapolis, Ind.; page 146 relied upon.