US2540696A - Drive mechanism for adjustable antennas - Google Patents

Description

Feb. 6, 1951 l w. J. SMITH, JR' y v 2,540,696

` DRIVE MECHANISM FOR 'ADJUSTABLE ANTENNAS A Filed July 1e, 1949 s sheets-sheet 1 IN V EN TOR.

HTTOR'NE Y Feb. 6, 1951 4 w. 1 sMlTf-v-l, JR y 2,540,696

DRIVE MECHANISM FOR ADJUSTABLE ANTENNAS Filed July 1e, 1949 's sheets-sheet 2 M/VENfoR.` lfefffiffffl, BY M w. J. SMITH, JR

DRIVE MECHANISM Fox ADJUSTABLE .fmTENNAs Feb. 6, 1951 3 Sheets-Sheet 3 Filed July 16, 1949 BY M3.

Patented Fel). 6, 1951 UNITED STATE sl PATENT OFFICE DRIVE MECHANISM FOR ADJUSTABLE' ANTENNAS 12`C'laims. l

This invention relates to a directionalhigh` frequency antenna and particularly to an adjustable antenna for use in the television and otherl high-frequency radio fields. f

In high and ultra-high frequency radio and television receivers, it is desirable that the signal strength of the received signal be as strong as possible. The utilization of a tuned, receiving antenna, capable of being rotated to any desired direction, greatly improvesy the performance of the receiver because the signal strength of the received signal is greater in proportion to the stray noises and interference effects than inthe case of an untuned non-rotatable antenna.- In

j order to provide for a maximum of received signal strength over` a band or range of frequencies, it is desirable to utilize an antenna that'may be- The elements of a.conventionaldirectional high-frequency radio or television antennal aren normally dimensionallypreset or tunedto provide a maximum received signal strength at a predetermined frequency. within the operating band. These normally preset elements arenot. tuned for other frequencies Within the operating band and, as a result, the signal strength decreases as the operating frequencies move away from the predetermined frequency at which the antenna is tuned. v f

Many conventional antenna systems lutilize a stacked array to minimize' the loss in 'signal strength at frequencies other' than the resonant frequency of the particular antenna elements.'

However, the stacked array only provides 'an anl tenna that' is turned at sever-al predetermined frequencies within the operating band anda loss in Signal strength occurs at frequencies 'apart from the resonant frequencies as determined the preset dimensions yof the antenna elements..A

Conventional television antennas are normally mounted in a fixed position, usually being ori-M ented to provide a maximum of a signal strength,

in a given direction.I A fixedv mounting is, not unduly objectionableV V,when the 4television transmitters are all located in a same .general area.` However, when several transmitters are located in different areas, with respect to Vvazimuth fromv the receiving antenna, an antenna with a fixed mounting will onlyprovide a maximum signal strength in a single direction.

This invention may be briefly described as an improved light-weight, high-frequency, directional antenna including means peculiarly adapted to dimensionally vary the size of the main receiving element so as to lselectively and accurately tune to any frequency withinl an operating band of frequencies, and improved and simple means to rotate vthe antenna in a horizontal plane. The means for Varying the dimensions of the antenna element consist of an improved, light-weight', simple .and inexpensive, driving mechanism leading yto increased efliciency, cheaper and simpler construction and a decrease of the loading effect on'the antenna.

An object of this invention is to provide an improved high-frequency antenna whose main receiving element may be dimensionall'y varied to tune the antenna to any frequency within a predetermined band of yoperating frequencies.

Another. object of this invention is the provi-Y sion of an adjustable antenna utilizing a folded dipole asv the main antenna element.

A further object of this inventionis the provision of an adjustableantenna vincluding an 'improved mechanismby which'the dimensions ofthe main antenna element may be remotely varied to provide for selective tuning over a predetermined band of operating frequencies.

Another object of 'this invention is the provision of anV adjustableantenna including an improved, light-weight,` and inexpensive driving mechanism which nevertheless provides very little loading effect on the antenna.

Still another object of theinvention istheprovision of an adjustable antenna including an improved driving mechanism of simple and inex-r pensive construction, whereby the'dimensions of' an antenna element may be dimensionally varied and whereby the antenna element may be rotatedV in the horizontal plane.l

Referring to the drawings:

Fig. l is an elevation, partially in section, show-v ing. the antenna andthe driving-mechanism therefor;

Fig. 2 is a plan view of the housing containing.

Figs.v l andY 3,7there is provided an and I2 extending outwardly therefrom. The two horizontal coaxial elongated portions II and I2 are of a length determined by the band of operating frequencies for which the antenna is to be designed. A lack of space on the figures permits only a fragmentary showing of the elongated portions II and I2, and it should be noted at this point that the antenna is symmetrical about its central portion 3. Consequently the following description, which will relate to the structure on one side of the central portion 9, is to be interpreted as including similar elements on the right hand portion of the central portion 9. The elongated portions II and I2 are shaped to provide internal guiding chambers such as that illustrated at I3 in Fig. 3. `Contained within the elongated portions II and I2 and defining a portion of the guiding chambers are guiding segments such as I4 in the guiding chamber I3. This guiding segment I4 is secured to the central housing portion 9 and is spaced from the upper and lower surfaces of the horizontal, elongated portions II andI2 asatISandI'I.

The external antenna housing, comprising the central portion 9, the cover plate 39, the elongated portions II and I2, and the guiding segment I4, is preferably molded or constructed from a nonconducting, light-weight, weather-resistant plastic, such as a suitable vinyl or polyester type of plastic.

Disposed within the horizontal, coaxial, elongated portions I I and I2 is the main receiving element. The presently preferred embodiment of the main receiving element, as illustrated in the drawings, is a folded dipole of flexible conducting material, such as a suitable metallic tape I8. This metallic tape is preferably secured to the housing at a central point such as I9 (see Fig. 3) by any suitable means such as the screws 2U and 2|. The tape I8 is disposed in the space I1 between the guiding segment I4 and the surface of the elongated portion II and extends outwardly into the guiding chamber I3. In the guiding chambers the tape, being of a iexible character is arcuately turned and extended inwardly ad- A array in the cylindrical tape receptacles such as the storage bins B5 and E6.

The metallic tape I 8 utilized to form the folded dipole may be suitably formed from a exible strip of steel or other suitable material, such as beryllium copper, similar in characteristics to i the tapes used in metallic rulers and measuring devices. The tape should be sufficiently flexible and resilient to permit an arcuate turning back upon itself as at 24 in Fig. 3. In addition the tape should be such that it rests in compressive sliding contact against the surfaces forming the guiding chamber I3 in the horizontal elongated portion II and its corresponding member formed by the horizontal elongated portion I2. found that a narrow steel or beryllium copper strip of approximately .00E-.007 inch in thickness possesses suitable characteristics for operational use.

As illustrated in Fig. 1, the tape I3 contains a series of equally spaced perforations 22 to permit the engagment of the tape I3 by the pawls 41, 48, 49 and 58. In the presently preferred embodiment of the invention as illustrated in the drawings, the perforations 22 are centrally disposed on the tape I8, however, the perforations It has beena reversible electric motor 21.

could be disposed adjacent to either edge of the tape. The series of perforations 22 terminate at each end in a perforation of greater length such as .that at 23 on Fig. 1. The terminal perforations 23 should be approximately three times the length of the intermediate spaced perforations 22. The reason for utilizing the enlarged terminal perforations 23 will be explained at a later point in the specification.

Included in the antenna construction is an improved drive mechanism peculiarly adapted to an antenna drive, requiring a simple, light-weight and inexpensive construction. This peculiarly adaptable drive mechanism will now be described in detail.

Referring /now to Figs. 1 and 2, the driving mechanism for dimensionally varying the length of metallic tape I8 contained within the guiding chamber I3 and its corresponding member on the other side of the central housing portion 9, is contained within a separate and `adjacent housing 2B. The housing 26 may be constructed of any suitable light-weight, weather-resistant material. Contained within the housing 28 is a prime mover, which, in presently preferred embodiment illustrated in the drawings, is shown as This motor 21 should be of a type that permits rapid starting and stopping. The motor 21 is mounted in the housing 26 by suitable mounting members such as the sleeves 25a and 25h encompassing the mounting bolts 25e and 25d.

Mounted on the shaft 21a of the motor 21 is a driving pinion 28. The pinion 28 meshes with and drives a gear 29 mounted on a shaft 30. The shaft 3D is encompassed at its opposite end by a solenoid 3I and is supported by a bearing mounted in the solenoid and generally designated at 32. The solenoid 3| issupported by the bearing plate 3 la. Loosely mounted on and' free to rotate about the shaft 33 is a driving worm 34. When the solenoid 3l is energized, the clutch member 33 and the integral sleeve 33h which encircles the shaft 3U and extends downwardly into the solenoid 3l which may be splined to the shaft 3i) for rotation with it, moves along the shaft 30 and engages the driving worm 34. The driving worm 34 is thus connected to the rotating shaft 30 through the clutch member 33 and rotates therewith. The clutch member 33 is provided with projections such as 33a which engage corresponding depressions such as 34d in the driving worm 34. The driving worm 34 meshes with and drives a worm gear 35 securely mounted on an enlarged portion 31 of a shaft 33. The enlarged lower portion 31 of the shaft 36 is rotatably mounted in lower portions of the housing 26, and the end of the shaft 31 is seated in a low-friction bearing such as the ball bearing 38. Through the abovedescribed gear train, any rotation of the reversible motor 21 results in a rotation of the shaft 36 whenever the solenoid is energized and the clutch member 33 is in engagement with the driving worm`34.

The upper end of the shaft 3B is rotatably mounted in a cover plate 39 which forms a part of the main antenna housing. Spaced inwardly from the end of the shaft 36 is a driving pin 40 which engages a key slot 4I in the gear 42. Rotation of the shaft 36 causes the driving pin 40 to engage and rotate the gear 42 in a corresponding direction. The gear 42 engages and counterrotates a companion gear 43 of similar size and shape. The gear 43 is mounted on a stub shaft 44, one end of which is rotatably mounted in and supported by the cover elementi, By the above-described gearing arrangement, any rotation of the shaft 36 results in anv equivalent' counterrotation of theshaft 44. Also mounted on the shaft 36 and adjacent to the gear 42 is an eccentric 45 having a` circular periphery. Similarly mounted adjacent to the gear 43 is a second eccentric 46 of similar shape and size. The eccentrics 45 and 46 are secured to the shafts 3S and 44 and, if so desired, may be cast integral with the gears 42 and 43. Mounted on the eccentric 45 is a pushing pawl 41 and Ian adjacent pulling pawl 4a. The pawls are mounted on the circular periphery of the eccentrics with a frictional fit which will permit relative movement between the eccentric andthe pawl if the pawl is restrained in its normal movement. The eccentric-45 is shaped to provide a reciprocating movement to the ends of the pawls 41 and 48.V

The end of the pushing pawl 41 is shaped to present a steep portion 60 to the edge of a perforation on the tape on the outwardly moving pushing stroke. Adjacent thereto is a slanting portion 59 which will slide over the edges of the perforations on the tape on the return stroke of the pushing pawl 41 without imparting movement to the metallic tape I8.

The shaft 44 and the eccentric 46 mounted thereon also mount a pushing pawl 49 and a pulling pawl 50 of a construction and mounting similar to the pawls 41 and 48. The configuration of the pulling pawl 50 and also the configuration of the corresponding pawl 48 mounted on the shaft 36 is clearly illustrated in Fig. 3. The end of the pulling pawl 50, which engages the tape I8, is shaped topresent a gently sloping portion 63 to the edges of the perforations on the outwardly moving stroke. This sloping portion 63 will slide over the perforations on the tape I8 without imparting movement thereto. Adjacent the gently sloping portion 63 is the engagingedge 64 which engages the edges of the perforations on the inwardly moving stroke and imparts movement to the tape. As the gripping portion 64 engages the edge of the perforations in tape I8 on each return stroke. the metallic taipe will be Withdrawn from the guiding chamber I3 in an amount equal to the length of the stroke of the pulling pawls 48 and 50.

The enlarged perforations 4on the tape, such as 23, limit the feeding action in advancing and retarding the antenna elements. The elongated perforations permit the pawls to move in their normal path but oifer no engaging surface or edge and thus terminate the movement of the tape.

construction to selectively position both pushing pawls or both pulling pawls in operative engagement with the perforations on the antenna clement.

The selective positioning means includes the stop collars 52 and 54 mounted on the shafts 35 and 44 respectively. Encompassing the- shafts 36 and 44 and comlpressively disposed between the stop collars 52, 54 and the gears 42 and 43 respectively are spring members 5I and 53. These spring members are normally under compression and press the gears 42 and 43 and the adjacent eccentrics 45 and 46 bearing the pawls 41 through 5D against the abutting surface A61 of the cover element 39. The resultant compression of the springs 5I and 53 results in a frictional surface contact between the pawls adj acently mounted on each of the eccentrics such as, for example, the pawls 41 and 48 on the eccentric 45.

Referring now particularly to Fig. 3, the selective positioning action of the above described spring members 5I and 53 will be described in detail. If the shaft 36 is rotated in a counterclockwise direction, the shaft'44, geared thereto, is counterrotated in a clockwise direction. The rotation of the shaft 36 in a counterclockwise Vdirection causes the pawl 41, due to its frictional mounting and the effect of the spring loading described above, to move in a counterclockwise direction out of engagement with the tape I8. This counterclockwise movement of the pawl 41 will be arrested by the stop pin 55 protruding from the housing 9. In addition, the counterclockwise rotation of the shaft 3'5 will cause the pawl 48 to move in the same direction. The pawl 48 thus moves into engagement with the metallic tape I8 coincidentally with the movement of the pawl 41 out of engagement with the metallic tape I8. As the shaft 36 rotates in a counterclockwise direction, the shaft 44 is counterrotated and thus turned in a clockwise direction. The clockwise rotation of the shaft 44 turns the pawl 49 so as to remove it from engagement with the tape I8. The clockwise movementof the pawl 49 is terminated by the stop pin 51 protruding from the housing 9. The clockwise rotation of the shaft 44 also moves the pawl 5U intoy engagement with the tape I8 coincidentally with the movement of the pawl 49 out of engagement with the tape, summarizing the above, it is seen that a r counterclockwise rotation of the shaft 36 effectively disengages both pushing pawls, i. e. pawls 41 and 49, from operative engagement with the tape and coincidentally moves both pulling pawls, i. e. pawls.5il and 48, into operative engagement with the tape I8.

In a similar manner, a clockwise rotation of the shaft 36 will disengage both pulling pawls, i.e. pawls 46 and Eil, from engagement with the metallic tape I8 coincidentally with the engagement of both pushing pawls, ie., pawls 4'! and 49 thereto. The stop pins 55 and 58 will limit the movement of the pulling pawls 56 and 46.

The presently preferred drive mechanism described above is peculiarly adapted to its 'inclusion as an integral part of an adjustable antenna due to its simplicity, eliicient operation and simple and inexpensive construction.

The pawls 41 through 56 may be suitably constructed of any strong, rigid, light-weight, nonconducting material an-d conveniently may be punched from a suitable pressed-fibre board or similar material. Itshould be noted that as these pawls are preferably constructed of material having suitable insulating qualities, isolation of the antenna tape from the remainder of the antenna drive mechanism oiers no insulation problems. In addition, the gears and eccentrics together with the shafts 36 and 44 may also, if desired, be made of a suitable light-Weight plastic.

Included qin the housing 9 vand' disposed adjacent tothe pawls41 through 50, are the tape vided two cylindrical tape receptacles 65 and 66.` of a depth determined by the width of metallic tape utilized forY the antenna element. Mounted on the inner periphery of the cylindrical tape receptacles 65 and 66 are a plurality of inwardly disposed spring members, such as 68. The spring members 68 are' roughly S-shaped and are mounted Yin Ythe receptacles 65 and 6B so as to presentanarcuate surface `to'k the moving tapes i. 'Ihese members 68 may be suitably punched from a strip of'spring steel and said strip may be mounted on the inner periphery of said receptacles `65 and 66 so that the members 63 engage the tape adjacent the perforations toform the unextended portions of the metallic tape I8 into 'n a tight coil. As the length of the antenna disposed within the elongated guiding chambers Il and I2 is shortened, the diameter of the coils in the receptacles 65 and 65 will be increased.

The increase in width of the coil presses against the tension of the spring members 68 and moves the free ends of said members to a position'closer to the periphery of the cylindrical tape receptacles 65 and 66. As the diameter of the coil in the receptacles decreases, the characteristics ofthe spring members 68 maintain a tightly wound coil; Y

While spring tensioned reels may be used if desired, the presently preferred and. above-described coil mechanism has the advantages of light-weight and efficient operation due to a lack of moving parts and is peculiarly adapted to an antenna structure of the type described.

Integrally associated with the antenna drive mechanism is an improved. means for rotating the antenna in the horizontal plane. The lower housing 26 is provided with suitable mounting brackets`10 for mounting the antenna on a pole or other suitable mount.

The motor 21, described in detail above, is utilized to provide necessary power for rotating the antenna in the horizontal plane. As described above, the pinion 2K8 mounted on the shaft 21-a of the motor 21 engages and rotates the gear 29 mounted on the shaft 30. Mounted adjacent the gear 23 on the shaft 30 is a pinion 1|. The pinion 1| engages anddrives a gear 12 mounted on a separate shaft 13. The shaft 13 is supported in a bearing mounting by the .solenoidy assembly 14 which in turn is mounted on the bearing plate Sla. Mounted on the shaft 13 in non-rotative engagement is a driving worm 15 which is thus free to turn relative to the shaft. Adjacent the driving worm 15 is a clutch plate 16, having projections thereon such as 16a, which is slidably mounted together with a plane member 1Gb which encircles the shaft 13 and extends downwardly into the solenoidy 14, on the shaft 13 and turns therewith. The clutch plate 15 and the plane 1611 are responsive to energization of the solenoid assembly 14, and when said4 solenoid assembly 14 is energized, the clutch plate 15 moves along the shaft 13 and the projections 16a thereon engage corresponding depressions 15a on the driving wormV 15 and rotates said worm 15in coinjunction with .the shaft 13. The,l driving worm Micasa-f1 8 15 is continiialngagemeidt with a large worm gear 11. y o A The worm gear 11 is securely and non-rotatablymountedon ythe hub 15 by a lockingpin 19. iThe hub 18fis integrally formed by the an;

tennahousingv 9 which extends downwardly into the non-rotating drive mechanism housing 26 and rotatably encompasses the'shaft 36. The hubl is supported'in part by the gear 35 but rotates independently;therefrom; The antenna housing 9 together with the horizontal` elongated portions I I'andgl2 containing the antenna elementyis Arotated inthe horizontal plane by the driving actionof the worm 15 engaging the wormi gear`11. The actuation of l the clutch plate 16 by the energilzationbf the solenoidI 1 4 provides a vsimple and effective controlY lfor antenna ro' tation. Y Y

In o rdertoprevent ,undue twisting ofthe electrical leads (not shown) to the'motor 21 and to the antenna elemets,"means are included to pre'- vent rotationiof the antenna beyond a 360 swing. Mounted'` on the large worm gear 11 is a protruding pin which engages and trips a limit switch 81. The limit switch '8| is mounted on'a cover plate 82 closing the 'upper portions of the lower housing 26. The limit switch 8l is suitably kcon-- nectedto the motor 21 yto reverse the direction of rotation when tripped. Y o

The cover plate 82 vis provided with a flanged portion '83 which 'encircles the upper enlarged cylindrical'portion '84 of the rotatable hub 18. The jointbetween the cover plate S2 and the upper enlarged cylindrical portion 84 of the rotatable h`ubv18 is covere'dby `a flexible waterproof sleeye such as '85 mounted on" the hub 18, as at 8B.

In accordance with the provisions of the patent statutes, I haveV herein described theprinciple of operation of this invention, together with the elements whichoI now consider the best embodiments such usewithin thes'cope of the appended claims.

.What is claimed is as follows: l 1. An adjustable high-frequency antenna,

comprising guiding means shaped to provide two l elongated guiding chambers for an expansible folded' dipole antenna element, said elongated guiding chambers defining a loop-shaped path for said dipole having an extent representing a position'o'f maximum remoteness for the end of the folded' dip'olejanlexp'ansible folded dipole yof flexible, conducting tape having a series of spaced perforations thereon disposed in U-shape and in compressive sliding contact with the surfaces of the guiding chambers, said flexible tape secured to the guiding means intermediate the elongated guiding chambersand means for advancing suc-v cessive portions of thetape remote from the turn of the U thereof, into and out of the guiding chambers, to elongate and shorten, correspondingly, thel U-s'haped extent of the member in the guiding chambersjincluding, a drive housing member; a'reversible electric Vmotor contained withinusaidw drive housing, anflrst drive shaft gearedv to'fand r'it'ated by said motor, a second drive ses?? seared@ nis .first drivefsha'ft and counterirotatedtherebycar pushing pawl and a expansible folded dipole antenna element, said l elongated guiding chambers defining a loopshaped path for said dipole having an extent representing a position of maximum remoteness for the end of the folded dipole, an expansible folded dipole of flexible, conducting tape having a series of spaced perforations thereon, the first and last perforations of said series being of greater length than the intermediate'perforations, said folded dipole being disposed in U- shape and in compressive sliding contact with the surfaces of the guiding chambers, said flexible tape secured to the guiding means intermediate the elongated guiding chambers, means for advancing successive portions of the tape remote from the turn of the U thereof, into and out of the guiding chambers, to elongate and shorten, correspondingly, the U-shaped extent of the member in the guiding chambers, including, Va reversible prime mover, a first drive shaft rotated by said priinemover, an adjacent second drive shaft geared to said first drive shaftand counterrotated thereby, a pushing pavvl and a pulling pawl eccentricallyl mounted on each of said shafts and positioned to engage the perforations on said tape, said pushing and pulling pawls being mounted on eccentrics shaped to cause the ends of said pawls to reciprocate along a predetermined path, spring loading means responsive to one direction of rotationof said first shaft to selectively position both pushing pawls in operative engagement with the perforations on said tape, whereby said pushing pawls engage successive perforations on said tape and advance said tape into the elongated guiding chambers, and responsive to the other direction of rotation of said first shaft to selectively position both pulling pawls in operative engagement with the perforations on said tape, whereby said pawls engage said perforations on said tape and retract said tape from said guiding chambers.

3. The adjustable antenna in accordance with claim 2, including, means for rotating the k aritenna element in the horizontal plane, comprising, a third shaft geared to and rotated by said prime mover, gearing means secured to said rotatable guiding means and rotated by said third shaft, and solenoid actuated clutching means intermediate said third shaft land said vprime mover. o

4. The adju'stable antenna in accordance with Iclaim 2,'including, means for storing the unextended portions of said flexible tape,compris ing, a pair of cylindrical receptacles contained within said guiding means, a plurality of inwardly extending spring members mounted on the peripheries kof said cylindrical receptacles and positioned to maintain the unextended portions of said flexible tape in coiled array.

5. An adjustable high-frequency antenna comprising a rotatable antenna housing member of non-conducting material shaped to provisis vide two coaxial, elongated, guiding chambers for an expansible folded dipole antenna element, said elongated guiding chambers defining a loopshaped path for said dipole having an extent representing a position of maximum remoteness for the end of the folded dipole, an expansible folded dipole of flexible, conducting tape having a series of spaced perforations thereon disposed in U-shape and in compressive sliding contact with the surfaces of the guiding chambers, said flexible tape secured to the antenna housing member intermediate the elongated guiding chambers, means for advancing successive portions of the tape remote from the turn of the U thereof, into and out of the guiding chambers, to elongate andv shorten, correspondingly, the U-shape extent of the member in the guiding chambers, comprising, a non-rotatable housing member, a reversible electric motor contained Within said non-rotatable housing, a first drive shaft geared to and rotated -by said motor, solenoid actuated clutch means intermediate said motor and said first drive shaft to control the rotation of said first shaft, a second drive shaft geared to said first drive shaft and counterrotated thereby, a pushing pawl and a pulling pawl eccentrically mounted on each of said shafts and positioned to engage the perforations on said tape, loading means responsive to one direction of rotation of said first shaft to selectively position both pushing pawls in operative engagement with perforations on said tape and responsive to the other direction of rotation of said first Shaft to selectively position both pulling pawls in operative engagement With the perforations on said tape, and means for rotating the antenna in a horizontal plane. including a third shaft Within said non-rotatable housing member geared to and rotated by said reversible electrical motor, second solenoid actuated clutching means intermediate said motor yand said third drive shaft to control the rotation of said third shaft, a gear mounted on said rotatable antenna housing member responsive to rotation of said third shaft whereby said antenna housing isrOtated in the horizontal plane.

6. An adjustable high-frequency antenna comprising a rotatable antenna housing member oi non-conducting material shaped to provide two coaxial elongated guiding chambers for a dipole antenna element, said elongated guiding chambers defining a path for said dipole having an extent representing a position of maximum remoteness for the end of the dipole, a dipole of exible conducting tape having a series of spaced perforations thereon disposed Within the guiding chambers, means for advancing successive portions of thetape remote from the ends thereof, into and `out of the guiding chambers, to elongate and shorten, correspondingly, the extent of the member in the guiding chambers, including, a non-rotatable housing member. a reversible electric motor contained therein. a first drive shaft geared to and rotated by said motor, a second drive shaft geared to said first drive shaft and counterrotated thereby, a pushing pavvl and a pulling pawl eccentrically mounted on each of said shafts and positioned to engage the perforations on said tane, loading means responsive to one direction of rotation of said first shaft to selectively position both pushing pawls in operative engagement with perforations on said tape and responsive to the other direction of rotation of said first shaft to selectively posimme@ 11 tion both pulling. pawls in .operative engagement with theperforations on Said tape.

7. The adjustable Vantenna in accordiance with claim 6 including, means for rotating lthe antenna element in theV horizontal plane, comprising, a third shaft geared to and rotated by said motor, gearing means secured tosaidrotatable antenna housing member and rotated by said third shaft, and means for, selectively engaging said third shaft and said gearing means. 8. The adjustable antenna in accordance with claim 6, including, .means for storingV the unextendedportions of said flexible tape, comprising,` a pair of cylindrical receptacles contained within said antenna housing member, a plurality of` inwardly extending, spring members mounted on the peripheries of said cylindrical receptacles and positioned to maintain the unextended portions of said flexibletape in coiled array.

9. An adjustable high frequency. antenna, comprising, an antenna housing member-of nonconducting material shaped to provideY two coaxial, elongated,guiding chambers for a dipole antenna element, .an expansible dipole of flexible, conducting tape having a series ofspaced perforations thereon disposed within saidV guiding chambers, means ,for advancing successive portions of thetaperemojte from the ends Ythereof, into and out of the4 guiding chambers, to elongate and `shor`ten,f correspondingly,V the extent of the element 'inthe guiding chambers, including, a'reversible motor, a pair of antenna advancing elements to engageA and intermittently advance said tape into said guiding chambers,

a pair of antenna withdrawing elements to engage and intermittently withdraw said tape from said guiding chambers, gearing' means intermediate said antenna advancing and withdrawing elements and said motor and means to selectively position said antenna advancing and withdrawing elements in operative engagement with the perforations on said tape.

10. The adjustable antenna in accordance with claim 9 including, means responsive to said reversible motor. to vrotate the antenna in the horizontal plane. Y

1l. An adjustable high frequency antenna, comprising, a rotatable antenna housing member of non-conducting material shaped to provide two coaxial, elongated, guiding chambers for an `expansible, folded dipole antenna element, said theantenna housing. member intermediate the elongated ,guidingf chambers, means for advancingsuccessiveportions vof the tape remote from guiding chambers, to elongate and shorten, correspondingly, the U-shaped extent of the member in the guiding chambers, including, a nonrotatable housing enclosingthe lower portion of said rotatable antenna housing member, a reversible motor contained within said non-rotatable housing, a pair of antenna advancing elements to engage said perforations and intermittently 'advance said tape into said guiding chambers, a pair of antenna withdrawing elements to engage said perforations and intermittently withdraw said tape from said guiding chambers, gearing means intermediate said antenna advancing andwithdrawing elements and said motor, means to selectively position said antenna advancing and withdrawing elements in operative engagement with the perforations on said tape, and means to rotate the antenna in the horizontal plane, comprising, gearing means secured to said rotatable antenna housing member, means intermediate said gearing means the turn of. the..U thereof, into and out of the and said reversible motor including selective clutching means tomechanically link said gearing means with said reversible motor.

12. An adjustable high frequency antenna, comprising guiding means for an antenna element, an'expansible antenna element of ilexible conducting tape having a series of spaced perforations thereon contained within said guiding means, means foradvancing successive portions of the tape into and outY of the guiding means, to elongate and shorten, correspondingly, the extent of the element in the guiding means, including, driving means, an antenna advancing element responsive to said driving means to engage and intermittently advance said tape into the guiding means, an antenna withdrawing element responsive to said driving means to engage and intermittently withdraw said tape from said guiding means, gearing means intermediate said driving means and said antenna advancing and withdrawing elements, means to selectively position said antenna advancing and withdrawing elements in operative engagement with the perforationson said tape, and means responsive to said driving means for rotating said antenna in the horizontal plane.

WALTER J. SMITH, JR.

REFERENCES CITED The following references are of record in the le of this patent:

UNTTED STATES PATENTS QTHER REFERENCES Radio and Television News, May 1949, page 163.

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