US2658144A - Indoor television antenna - Google Patents

Description

Nov. 3, 1953 G. P. KEARSE INDOOR TELEVISION ANTENNA Filed July 9, 1949 M Mae?.

Patented Nov. 3, 1953 INDOOR TELEVISION ANTENNA George P. Kearse, Chicago, Ill., assignor to American Phenolic Corporation, Chicago, Ill., a corporation of Illinois Application July 9, 1949, Serial No. 103,835

(Cl. Z50-33) 3 Claims.

This invention relates to television antennas and has particular reference to a novel antenna of portable construction and suitable for indoor use, yet adapted to receive signals throughout all of the present television channels without adjustment.

In the present state of the television art many antennas have been developed, and while their designs are many and varied, they may be roughly classified into two groups; that is, those intended for permanent outdoor rooftop installation, and the indoor or living room models. Certain of the outdoor structures have been so designed and constructed as to receive frequencies anywhere within the television spectrum without adjustment. These devices have, however, been of such inherently large, bulky and ungainly nature as to make their use indoors impractical, if not impossible. The indoor types, on the other hand, have either been entirely incapable of reasonably high gain performance throughout the wide range of frequencies of the channels presently assigned to television, or have been able to cover the band only by the use of manually adjustable elements. At present one of the most widely used types of indoor antenna is known as the V type, consisting of a pair of arms extending upwardly and outwardly from a common base to form generally a V shape, and while these have shown themselves to be reasonably satisfactory when adjusted for any one channel of the television spectrum, yet they are critical as to length and, therefore, must be made with telescoping arms if they are to tune to all channels, so that the arms can be manually lengthened or shortened according to the frequency of the signal to be received. This is disadvantageous not only in that it requires manual manipulation of the antenna arms whenever the receiver is switched from one television channel to another, but also by reason of the fact that the adjustment of the arms is ordinarily only a very rough approximation at best, being accomplished on a trial and error basis by the individual tuning the receiver. This approximation is further broade ened by the effect of body capacity of the individual tuning the antenna.

Many eiorts have been made to provide antenna arrays capable of receiving signals throughout the entire spectrum, but although the problem involved in accomplishing this may appear simple enough until its solution is attempted, experimenters in the field have long since learned that certain technical factors,

seemingly not thoroughly understood, appear to prevent the successful functioning of any of the indoor arrays heretofore proposed. The result, so far as known to the applicant, has been that no antenna has heretofore been devised that is capable, Without adjustment, of successfully receiving signals from all channels and is yet of size, shape, structure and design suiting it to living room use.

It has been discovered, however, that satisfactory results may be obtained throughout all ofthe television frequency bands by employing a novel four-electrode structure as here disclosed. This comprises, as its essential elements, a pair of relatively long arms oriented in angular form, with a second pair of shorter arms lying in the same plane but oriented at a considerably greater angle to each other. The results obtained with the antenna are particularly good when these four elements are joined to the transmission line with a unique cross-over network wherein the long arms on one side are joined to the short arms on the opposite side.

It is accordingly the primary object of the invention to provide a novel and efficient allchannel indoor television antenna as indicated above, and in furtherance of this general object it is also an object of the invention to provide a construction that is electrically eilicient throughout, yet of inherently pleasing appearance and attractive design, so that it will be acceptable in the living rooms of modern homes.

An additional object is the provision of an antenna structure as indicated above wherein the various parts are so constructed and related that the antenna may be easily and compactly packaged for sale and distribution, yet when assembled will function as a compact, self-con tained unit; including a base that may rest on any convenient supporting surface and serves to support the antenna arms in the desired orientation, so that there is no need for permanent installation or mounting of the parts.

A preferred embodiment of the invention is illustrated in the drawings herein, in which:

Figure 1 is a front elevational view, showing an antenna constructed in accordance with these teachings;

Figure 2 is enlarged fragmental detail sec.

tional view taken substantially on the plane of the line 2.-2 of Figures 1 and 3; and

Figure 3 is a fragmental detail sectional view taken substantially on the plane of the line 3 3 of Figure 2.

The antenna assembly is mounted on and 3 supported by a nat base I0, which is preferably of circular shape and provided around its outer edges with spaced apertures II in which resilient feet I2 may be fitted to rest on any suitable supporting surface and space the lower edge flange I3 of the base sufficiently above the supporting surface, so that a nat, parallel, twin lead transmission line W may' extend outwardly from the center of the base below the edge flange and between the flange and the surface on which the antenna is carried. The base is preferably formed of molded insulating plastic,r opaque polystyrene being employed in the commercialv /j on the right, and thence to the sleeve in which the left hand short arm 33 is carried.

In practice, an antenna assembly constructed according to these teachings is provided with long arms of l1'7-inch length and short arms of inches in length, which will give satisfactory gain characteristics throughout all of the 13 television channel's-v presently assigned; Further, this broad band receptionE is obtainedwithout need for adjustment or manual manipulation of the antenna arms. The unit is self-contained and compactquickly assembled or disassembled,

embodiment of the unit to givehigh efficiency,- s

low-loss performance. be Weighted to give physical stability to the unit. This is preferably done by a circular meta-l. disc I5, housed inside of the base flange I3 and secured in position by a pair of machine screws I6. These screws also serve to hold a pair of opposite arm mounting portions I'I,v also-formed of molded polystyrene, and secured' to eachother.. as by thel screws or tubular rivets I8. The mem; bers I-I are substantially identical and opposite in shape, and are provided on their abutting inner surfaces withl two pairs of divergent grooves to receive the antenna arms-,- with rcJ cesses I9, 20, 2I1 and 22 betweenthe grooves;l

The inner pair of grooves 23 are disposedi at an angle of 55 degrees from the horizontal so they lie at an acute angle of 70- degi'eesfwithl re spect to eachother. 'I-'heouter grooves 24I are disposed atan angle of 25- degrees from the'hori zontal so that they lie at an obtuse angle of 130 degrees from eac'h. other. Each of the grooves 23'and 24 is provided withl a springsleeve'contact terminal indicated' in Figui-e 3 by the numerals 25", 26, 21l andi 213i.y These spring'. contact sleeves serve to frictionally support the actual antenna elements which comprise an inside pair cri relatively long arms 3l and 32 mounted tnef sleeves 25" and 26, and an. sid pai/'1f 33? aid 34 in the sleeves 2'1 and 2E. The' two-#pairs of arms lie in tl'ie` same plane, so that the' two arms on each side of center assume positions about degrees angularly disposed from each other. All of the arms may be formed ofl slender aluminum rods, and for conveniencev in manufacture, assembly and packaging', the arms 3I' and 3`2` are preferably formed in two sections; with* vmetallic spring' coupling' sleeves 35 and 36 joining the inner and outer sections. As illustrated, each of the arms of the' antenna terminates' in. a plastic ball 31 which, while serving no essential electrical function, aids in assembling and' disassembling the unit and improves its appearance.

The four arms of the unit are joinedv to the parallel leads 38 and 39 of the lead-in I4' (preferably a length of 300 ohm radio frequency transmission line) by a unique cross-over net- Work whereby a long arm on one side and a short arm on the other are joined to each lead of the transmission line. This cross-over networky consists of the internal leads 4I and 42 extending reversely with respect to the trans*- If desired, the base-may' and" yet is of" pleasing appearance and attractive design; so that it is. acceptable in the surroundings# of a well appointed home. It is self-supporting; requiring no mounting nor permanent installation, and has been found to give unequalle'd' picture brightness in all locations suitablefor indoor antenna use.

Having thus described. my invention, what I claim. as newy and. desire to secure by. United States Letters Patent is.:

. l. An indoor television antenna comprising,.in combination, a. relatively broad, flat, horizonf tally disposed. base ot insulating..materialhaving a stabilizing weight therein with paired. mounting. members. securing rigid antenna elementsin projecting relationship. to saidbase; said mount'- ing members comprising a. pair. of complementary semicircular. uprights having. opposed surfaces in direct engagement with. each other and. meeting in a plane perpendicular. to the base, with a plurality of grooves in said surfaces' and.v

angularly disposed with respect to each other; the grooves in each of the complementary uprights being in registry with the grooves in the other upright and coacting. to form angularly divergent sockets adapted to receive. the aforementioned. rigidl antenna elements,1 with a friction contact. clip affixed. within. each of said.

sockets 4and a transmissionline electrically joinedV to said contact clips; said. rigid. antenna elements consisting. of` a plurality of. slender, selfsupporting 4conductive metal rods detachably. afiixed within said sockets and. comprising. a relatively long pair disposed at an. acute angle to each other and supported. in two adjacent. sockets, with a relatively shorter. pair inde-- pendently supported in other sockets and dis- Yposed. at an obtuse angle with respect to each other in the same plane as the long pair.

2. An indoor' television antenna comprising, in combination, a horizontally disposed'. stabilizing base having. foot portions whereby the base may 1 be supported on a horizontal surface, with. paired'.

mission line leads, so that instead of having the f mounting members securing rigid antenna. elements in projecting relationship to said base; said mounting members comprising a pair of complementary uprights having opposed surfaces in direct engagement with each other andl meeting in a plane perpendicular to the base, with a plurality of grooves in said surfaces and angularly disposed with respect to each other; the grooves in each of the complementary uprights being in registry with the grooves in the other upright and coacting to form angularly divergent sockets adapted to receive the aforementioned rigid antenna elements; said rigid antenna elements consisting of a plurality of slender', self-supporting' conductive metal rods affixed within said sockets and comprising a relatively long pair disposed at an acute angle to each other an'd supported in two adjacent sockets, with a relatively shorter pair' independently supported in other sockets and disposed at an obtuse ang-le with respect to each other.

3. An indoor television antenna comprising, in combination, a relatively broad, flat, horizontally disposed ibase of insulating material, together with a complementary upright secured in direct engagement with and perpendicular to the base; said upright having four angularly divergent sockets lying in a common plane perpendicular to the base and each adapted to receive and support in projecting position a rigid antenna element; a friction contact clip af'nxed within each of said sockets and adapted to engage the inner end of the antenna element therein, and a transmission line electrically joined to said contact clips; said antenna elements consisting of two pairs of conductive metal rods, comprising a relatively long pair disposed at an acute angle to each other and supported in two adjacent sockets, and a relatively shorter pair independently supported in other sockets and disposed at an obtuse angle with respect to each other.

GEORGE P. KEARSE.

References Cited in the le of this patent UNITED STATES PATENTS OTHER REFERENCES Radio Electronics, October 1949, page 30.

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