US2259628A - Adjustable antenna unit - Google Patents

Description

Oct. 21, 1941. FENER ETAL 2,259,628

ADJ US TABLE ANTENNA UN IT Filed June 28, 1941 2 Sheets-Sheet l 2/ INVENTORS ALFRED F'ENER BY JOHN ALESI ATTORNEY Oct. 21, 1941. A. FENER ET AL 2,259,628

ADJUSTABLE ANTENNA UNIT Filed June. 28, 1941 2 Sheets-Sheet 2 jjg? . INVENTORS ALF RED PENER JOHN ALESI ATTORNEY Patented Oct. 21, 1941 ADJUSTABLE ANTENNA UNIT Alfred Fener, Brooklyn, and John Alesi, New York, N. Y.

Application June 28, 1941, Serial No. 400,212

v(Cl. 250-33) 13 Claims.

The present invention relates to di-pole antennae, and, more particularly, to a universally adjustable di-pole antenna unit of novel and improved character.

In our U. S. Patent No. 2,215,810, granted to us on September 24, 1940, we have disclosed an antenna unit with universal mounting in which a rod type antenna is combined with a rotary joint of special character to permit facility of adjustment to a position where strength of the signal received is at an optimum and interference with other signals or disturbances is at a minimum. Our present invention is related to the said U. S. patent and constitutes a further improvement thereover.

As those skilled in the art know, the so-called di-pole antennae have come into increasing use recently as a result of the special advantages which they offer particularly in the reception of short wave, television and frequency-modulated signals. Generally speaking, the di-pole antenna, or as it is frequently referred to for the sake of brevity, the di-pole, comprises a pair of metallic rods having a length which is in part determined by the wave-length of the signals to be principally received, such as, for example, about 6 feet. These rods are mounted in a substantially linear direction with respect to each other and are individually connected to a transmission line or wir through which the signals picked up may be transferred to the receiving set either directly or through a suitable coupling device. The two rods of the di-pole may be arranged either in a horizontal direction or in a vertical direction according to whether horizontally or vertically polarized waves are to be received. In this sense the art distinguishes between a horizontal and a vertical di-pole. In some instances a horizontal and a vertical dipole have been combined into a single unit comprising four rods arranged in radial direction, 90 degrees apart from each other.

Practical experience with di-poles has shown that in most cases it is necessary or desirable to adjust the rods of the di-pole in order to improve the electrical characteristics of the systern or in order to take care of local mechanical conditions involved in mounting the di-pole on windows, gabled roofs, chimneys, parapet walls, soil pipes, fences, trees, wash line posts and on other regular and irregular surfaces which happen to be available at the place of mounting. While it was already suggested to constitute the di-pole in the form. of a pair of rods connected to form a rigid mechanical unit which is rotatable about a pivoting point, as far as we are aware of, all of these prior adjustable di-pole structures were relatively expensive and complicated, mechanically weak and of a restricted gestions and proposals were made to solve the outstanding problem, none of these suggestions and proposals was completely satisfactory and successful on a practical and commercial scale.

We have discovered an extremely simple and completely satisfactory solution of the outstanding problem.

It is an object of the present invention to provide a di-pole antenna of novel and improved character which eliminates and avoids the disadvantages and inconveniences of conventional di-poles.

It is another object of the invention to provide a di-pole adapted to be mounted on the top of a pole or on restricted supporting surfaces of the type referred to in the foregoing and which is readily adjustable into any desired direction to provide optimum conditions of reception and freedom from interference and noise.

It is a further object of the invention to provide a di-pol antenna in which the rods may be individually and collectively adjusted to any desired position within a wide range and may be positively fixed in such position after it has been obtained.

It is also within the contemplation of the invention to provide a di-pole unit with a universally adaptable mounting and having a coupling unit incorporated therein located in immediate proximity to the antenna rods proper and completely protected against the elements.

The invention also contemplates a di-pole unit of universally adjustable type which is simpl in construction and to operate and which may be readily manufactured and sold on a practical and commercial scale at a low price.

Other and further objects and advantages of the invention will become apparent from the Fig. 5 is a circuit diagram of a preferred cou- V pling device employed in connection with the dipole antenna of the invention; and

Fig. 6 is a fragmentary perspective view of a modified embodiment of the present invention. Broadly stated, according to the principles of the present invention, we provide a cylindrical base member preferably constituted of a suitable adjustability. Although also various other suginsulating material having great mechanical strength, such as porcelain or Bakelite. This member is mounted at the end of a heavy rod or post by means of a diametrically extending bolt or screw, the other end of said post being ina nut thereon, the circular brackets are likewise tightened in their respective grooves or depressions to positively fix the position of the brackets or rings and thereby the position of the di-pole rods on the cylindrical member while adjustment is readily possible at any time by loosening the said nuts. Of course, the number of rods may be 2 or 4, or any other number according to the type of di-pole antenna contemplated and the cylindrical member may be provided with 2, 4 or more grooves and circular brackets accordingly. We have found it very desirable to incorporate suitable coupling elements or transformers into the cylindrical base member to facilitate proper connection and operation thereof. To accomplish this, the cylindrical member is preferably formed with appropriate cavities, as

' it will be more fully explained as the description proceeds.

Referring now more particularly to Figs. 1 to 4 of the drawings, a preferred embodiment of the invention will be described. Reference character I denotes a substantially cylindrical base member constituted of porcelain, Bakelite, or some other suitable insulating material having great mechanical strength and resistance against the elements. Base member l is provided with two cylindrical and coaxial cavities 2 and 3 both of which have their axes vertically to that of base member I. Cavity 2 is considerably smaller in diameter than cavity 3, and the two cavities are connected with each other by means of a short and likewise coaxial and cylindrical channel 4. The base member I is also provided with a pair of circumferentially arranged grooves 5 adapted to receive and to hold a pair of circular brackets 6 of appropriate size made of brass or some other metal. The two ends of each circular bracket 8 are provided with extensions I in which there are holes through which a metallic rod-holding element 8 may pass. These rod-holding elements are formed with a small diameter portion 9 which may pass through the holes in the extensions of the brackets and with a large diameter portion between which there is a shoulder l adapted to rest on the extension I of bracket 6 while one of the ends of the rod holding element 8 is threaded at H and is adapted to receive a nut l2 and interposed washer l3. Brackets 6 have such dimensions that they can normally slide in the corresponding circular grooves of base member I and may be fixed in any oneoi' their positions by tightening nut l2 whereby the brackets will be firmly pressed against the circumference of the grooves and will be fixedly held thereon by their powerful brake-shoelike action. The other end of rod-holding element has a cylindrical bore ll therein for the insertion of the antenna rod proper. The antenna rods are made of a light aluminum alloy or stainless steel of suitable character with a cylindrical cross section one end of which is inserted into bore ll of the rod-holding element 8 and is retained therein by friction or tight fit alone or, if desired, by means of a set screw (not shown). In view of the fact that the antenna rods are of substantial length, such as for example 6 feet each, it is generally preferred to assemble them from a plurality of pieces which are rigidly connected together at their ends. A preferred form is shown in Fig. 1 whichdepicts each of the antenna rods as constituted of two pieces I5 and ll of which the one with the larger diameter I8 is inserted'into bore ll of rod-holding element 8 while that of the smaller diameter I6 is inserted into a corresponding recess or bore I! of rod II.

The cylindrical base member I is fixedly mounted on a suitable mounting surface by means of mounting elements which will be best observed in Figs. 1 and 3. These mounting elements essentially comprise a disk l8 of, an insulating material, such as Bakelite, inserted into a corresponding. depression I! in base member I. A threaded hole 20 at the end of a mounting rod 2| is adapted to cooperate with the end of a long scre'w 22 passed through cavities 2 and 3, channel I, and a central hole 22 in Bakelite disk It. As it will be readily seen in Fig. 3, screw 22, when tightened in threaded hole 20, will firmly press disk I8 into depression IQ of the base member whereby the rigid connection of this member to the vertical mounting rod 2| will be assured. The lower end of mounting rod 2| is inserted in a sleeve or socket 24 and is fixed therein by means 4 of a set screw 25 while the socket is connected by means of its lower threaded end to a mounting plate 21. Mounting plate 21 is mounted by means of screws 28 on the top of a pole 29 of appropriate length, or on some other suitable mounting surface.

We have found that a di-pole antenna of the described character provides the best results if suitable electrical coupling elements are interposed between the antenna and the transmisson line. The mechanical arrangement of these coupling elements appears in Fig. 3 while their electrical connections will be best understood by referring to Fig. 5 of the drawings. Referring now to Eig- 3, the coupling elements are. housed within cavity I of the casing which is closed at its lower end by means of disk l8 inserted into the corresponding circular recess I! of base memher and resting on a shoulder 30. The coupling elements comprise a pair of transformers II and 32 mounted on a hollow iron core 33 and have.

a thin insulating plate 34 therebetween on which are mounted soldering lugs 35. These soldering lugs serve for connecting the leads of transformers 3| and 32 to cables 36, which are passed through four openings 31, 38, 39 and 40 provided in insulating disk It (Figs. 3 and 4). Of these cables the ones passed through holes 21 and 38 of disk I l are connected to the two antenna rod holding elements 8, the cable passed through hole ll is connected to a suitable ground, while the cable passed through the slightly larger hole II is a twisted transmission line for conducting the'oscillatory energy picked up by the di-pole to a receiving set either directly or through another coupling device located in proximity to the receiving set.

1 The electrical elements provided in the coupling device and their electrical connections will be best understood from Fig. 5. Transformer II has a primary winding 4| connected between the capacity 41 is connected across secondary winding d4 of transformer 32 in order to provide a by-pass of low impedance for the oscillations of relatively high frequency. In view of the fact that this type of coupling device is well known to those skilled in the art and does not form part of the present invention, no detailed description of its operation will be necessary. It will be suflicient to state that the oscillations of lower frequency will be principally transmitted by means of transformer 32 having a greater number of windings.

From the foregoing description, the operation of the di-pole antenna of the invention will be readily understood by those skilled in the art. When it is desired to install the di-pole antenna embodying the invention, first the mounting plate 21 with socket 24 attached thereto is mounted on a suitable surface, such as the top of a pole 29, by means of screws 28. Hereafter, supporting rod 2| is adjusted in socket 24 and is fixed in such position by means of set screw 25. This determines the direction of the axis'of base member l and thereby the plane in which antenna rods I5 may be adjusted. Finally, rods l5 are adjusted into their desired respective positions in which best conditions of reception are obtained and are fixed in such positionsby tightening nuts l2 whereby the antenna rods will be positively fixed and accidental displacements thereof are rendered impossible. In view of the fact that the di-pole unit is preferably shipped with the coupling device already inserted and hooked-up to the antenna rods and transmission line respectively, all that is neededis to connect the ends of the twisted transmission line coming out of the base member to the transmission line connecting the di-pole to the receiving set either directly or through another coupling device of similar character. Generally speaking, the antenna rods are both adjusted either in the horizontal direction or in the vertical direction according to the circumstance whether horizontally or vertically polarized waves are to be received. Obviously, it is also possible to adjust the rods into any other position intermediate to the horizontal and the vertical, this being particularly desirable when obstructions in proximity to the di-pole distort the polarization of the waves. Likewise, in some cases for similar reasons it is desirable to adjust the two antenna rodsinto such position where they enclose an angle with each other, this being readily accomplished by the individually adjustable character of the rods.

Fig. 6 illustrates a modified embodiment of the present invention in the form of an antenna unit equipped with four individually adjustable antenna rods. This modified embodiment essentially comprises a base member 5| in all respects similar to base member I shown in Fig. 1 except that there are two grooves 55 at each end thereof whereby it is possible to mount four circular brackets 56 thereon. Each of these brackets has extensions 51 with holes therein through which passes a rod-holding element 58 identical with the corresponding element 8 of Fig. 1. A nut 62 at the threaded end of rod-holding element 58 makes it possible to fix the rod holding element and the bracket in any desired position on the base member. Antenna rods are inserted into bores 64 at the other end of each rod-holding element in the same way as in the previously described embodiment. Likewise, a circular insulative plate or disk 68 is inserted into a corresponding depression of base member 5| and serves as a connecting member for mounting the base member at the end of a supporting rod 13 which may be inserted into a socket It with set screw 11 and a mounting plate 19 whereby the base member may be mounted on any desired supporting surface. The principal advantage oi. a device of the described character is the possibility of combining a horizontal di-pole with a vertical di-pole which may be either selectively or cola lectively employed for the purposes of radio reception. Generally it is unnecessary to employ any switching devices for the selective connection of the two pairs of rods to the common output. The two di-poles may be permanently connected in parallel since the horizontally adjusted di-pole will be substantially unafiected by the vertically polarized waves, and vice verse. of course, the base member may or may not contain suitable coupling elements of the type shown-in Fig. 5. Adjustment of the rods 65 is accomplished in the same manner as that of rods l5 shown in Fig. 1. In view of the similarity of construction, the operation of this modified embodiment of our invention will be readily understood by those skilled in the art without any further explanation.

Although the present invention has been described in connection with a few selected embodiments thereof, variations and modifications may be resorted to by those skilled in the art without departing from the principles of the present invention. We consider allof these variations and modifications as within the true spirit and scope of the present invention as disclosed in the foregoing description and defined by the appended claims.

We claim:

1. An antenna unit comprising in combination a cylindrical base member, means for mounting said base member on a supporting surface, rodholding means slidably and adjustably mounted on said base member, at least one antenna rod in said rod-holding means, and means for fixing :aid rod-holding means in their adjusted posiion.

2. An adjustable antenna unit of the di-pole type comprising in combination a cylindrical base member, means for fixedly mounting said base member on a supporting surface, a pair of rodholding members slidably mounted and independently adjustable on said base member, an antenna rod held in each of said rod-holding members, and means for positively locking said rod-holding members in their adjusted position.

3. An adjustable di-pole antenna unit comprising in combination a cylindrical base member, means for mounting said base member on a supporting surface, a pair of rod-holding members surrounding the circumferential surface of said base member and slideably displaceable thereon, an antenna rod in each of said rod-holding member and adjustable with respect to said base member, and means for locking said rod-holding members and said rods in their adjusted position.

4. -An antenna unit comprising in combination a cylindrical base member, rod-holding means slideably and adjustably mounted on said base member, at least one antenna rod held in said rod-holding means and continuously adjustable in a plane vertical to the axis of said base memher, means for locking said rod-holding means and said rod in their adjusted position, and means for mounting said base member on a supporting surface for rotation about an axis vertical to said surface thereby to adjust the plane in which the rod is adjustable.

5. A universally adjustable di-pole antenna unit comprising in combination acylindrical base member, a pair of rod-holding elements surrounding the circumferential surface of said base member and slideably displaceable thereon, an antenna rod in each of said elements and adjustable in a plane vertical to the axis of said base member, means for fixing said elements with respect to said base member, means for rotatably mounting said base member on asupporting surface about an axis vertical to the axis of the base member, and means for locking said base member with respect to said supporting surface.

' 6. An antenna unit comprising in combination a cylindrical base member, mounting means for mounting said member on a supporting surface, at least one circular bracket surrounding the circumferential surface of said base member and rotationally displaceable thereon, rod-holding elements operatively associated with said bracket, an antenna rod held by each of said rod-holding elements and adjustable with respect to said base member, and means for deforming said bracket to frictionally lock the same and the antenna rod connected thereto in its adjusted position.

7. An adjustable antenna unit comprising in combination a cylindrical base member constituted of an insulating material, means for mounting said member on a supporting surface, a plurality of metal brackets on said base member having an annular portion substantially surrounding the circumferential surface of said base member and having oppositely disposed exten- 'sions, a rod-holding element with an antenna rod for each of said brackets and held betweensaid extensions, said brackets and said antenna rods being continuously adjustable with respect to said base member, and means for compressing the annular portions of said brackets to fix the rodholding elements and the rods in their adjusted positions.

rod in said bore adapted to be continuously adjusted in a plane vertical to the axis of the base member, and means for mounting said base member on a supporting surface.

10. An adjustable antenna unit comprising in combination a cylindrical base member, a shaft depending from said base member, a moimting socket for rotatably holding said shaft and adapted to be mounted on a supporting surface. means for fixing said shaft in said socket against rotation, rod-holding means mounted on said base member and slideable and adjustable on the circumference thereof, at least one antenna rod held by said rod-holding means, and means for fixing said rod-holding means in their adjusted position.

. 11. An adjustable antenna unit comprising in combination a cylindrical base member constituted of an insulating material, a shaft dependi ing from said base member, a mounting socket for rotatably holding said shaft and adapted to be mounted on a supporting surface, means for fixing said shaft in said socket against rotation, a plurality of metal brackets on said base member having an annular portion substantially surrounding the circumferential surface of said base member and slideable thereon, a rod-holding element with an antenna rod for each of said brackets, and means for compressing the annular portions of said brackets to fix the rod-holding elements and the rods in their adjusted position.

12. An adjustable antenna unit comprising in combination a cylindrical base member consti- 8. An adjustable antenna unit comprising in a combination a cylindrical base member constituted of an insulating material and having a plurality of circumferential grooves thereon, a

metal bracket having an annular portion in each of said grooves and having an extension at each end, a rod-holding element for each bracket passed through holes in said extensions having a rod-receiving bore at one end and a threaded portion at the other end adapted to adjustably hold an antenna rod with respect to said base member, and a threaded member cooperating with said threaded portion of the rod-holding element to compress the annular portion of the bracket and thereby to fix the rod-holding element in such adjusted position.

' 9. An adjustable antenna unit comprising in combination a cylindrical base member constituted of an insulating material and having a plurality of circumferential grooves thereon, a metal bracket in each of said grooves having an annular portion and an extension at each end thereof, said bracket being adapted to be slidably and frictionally displaced in said groove, a locking member having a rod holding bore for each bracket constructed and arranged to bring said. extensions together and thereby to fix the bracket against such displacement, an antenna tuted of an insulating material, a transverse cavity extending throughout said member for the insertion of a threaded member at one end thereof and for the insertion of a correspondingly threaded and depending shaft at .the other end thereof, said shaft being securely held by said threaded member with its axis at right angles to the axis of said base member, a plurality of annular brackets surrounding the circumferential surface of said member and having extensions at each end, each of said brackets being adapted to hold an antenna rod for independent adjustment with respect to said base member, a loclqpg bolt for each of said brackets to fix the same and the associated antenna rod in their adjusted positions, and mounting means for rotatably receiving said shaft.

13. An adjustable antenna unit comprising in combination a cylindrical base member constituted of an insulating material, a transverse cavity extending throughout said member having an upper portion and a considerably larger lower portion. an insulative plate closing the outer end of said lower portion, a threaded member extending throughout said cavity and through said plate adapted to engage a correspondingly threaded portion of a vertically depending shaft and to rigidly connect the same to the base member with its axis at right angles to that of said member, a plurality of annular brackets surrounding the circumferential. surface or said member and slideably adjustable thereon, a looking bolt with an antenna rod-holding bore for holding said shaft for attaching the unit to a supporting surface.

ALFRED FENER. JOHN ALESI.

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