US2695957A

US2695957A - Projectable antenna

Info

Publication number: US2695957A
Application number: US18253A
Authority: US
Inventors: Joseph H Cone
Original assignee: Casco Products Corp
Current assignee: Casco Products Corp
Priority date: 1948-03-31
Filing date: 1948-03-31
Publication date: 1954-11-30
Anticipated expiration: 1971-11-30

Description

NOV. 30, 1954 1 H, CCNE 2,695,957

PROJ ECTABLE ANTENNA Filed March 31, 1948 4 Sheet's-Sheet l lllllll 'Illlllll r IN V EN TOR. 43 JOM/Qa H Coffe www Mm .A TTORNE'YS NOV. 30, 1954 1 H (CQNE 2,695,957

PROJECTABLE ANTENNA Filed uaroh s1, A194s 4 Sheets-Sheet 2 JNVENToR. l/o Sep/L ff. ('0/1 e www MIK/@wk A TTORNEYJ Nov. 30, 1954 J. H. coNE 2,595,957

PROJECTABLE ANTENNA Filed March 31, 1948 4 Sheets-Sheet 5 A TTORNEXS' Nov. 30, 1954 J. H. coNE 2,695,957

PROJECTABLE ANTENNA Filed March 31, 1 948 4 Sheets-Sheet 4 JNVENToR. Jose/Ufo fl. Cone ATTRNEKY Patented Nov. 30, 1954 PROJECTABLE ANTENNA Joseph H. Cone, Bridgeport, Conn., assignor to Casco Products Corporation, Bridgeport, Conn., a corporation of Connecticut Application March 31, 1948, Serial No. 18,253

5 Claims. (Cl. Z50-33) This invention relates to retractable and extendable telescopic radio antennas, and more particularly to semiautomatic power-operated telescopic antennas such as are used in automobiles and the like.

An object of the invention is to provide an improved power-operated telescopic radio antenna of the type having low, substantially uniform capacity to ground for all adjusted positions, which antenna is positive and reliable in operation at all times, extremely small and compact in size, and may be adapted to various different space requirements whereby it is universally applicable to all styles and makes of automobiles.

Another object of the invention is to provide an irnproved power-operated antenna as above, which efficiently utilizes the power consumed by it, to the end that the motive means need not be large nor require a great amount of space.

A further object of the invention is to provide an improved power-operated telescopic antenna of the above type, in which the combined motive means and powertransmission means are arranged to be extremely compact, so that the overall dimensions of these components are relatively small.

Yet another object of the invention is to provide an improved power-operated telescopic antenna for an automobile, as characterized above, in which the telescopic sections may be readily manually raised or lowered from outside the car should this be desired, without requiring energization of the motive means for the antenna, or without first requiring that a disconnect or declutching operation be performed.

Still another object of the invention is to provide an improved power-operated telescopic antenna as above, which is economical to manufacture.

In accomplishing the above objects there is provided by the present invention, in combination with a plurality of telescoping antenna sections, a novel power means and power-transmission means for actuating the antenna sections, including a very compact, reversible electric motor. This motor has a novel construction, comprising a hollow field core which surrounds and houses one end bearing for the motor armature shaft, whereby the motor is made compact and relatively small in size while at the same time providing suicient power, through the improved power-transmission means, to reliably operate the antenna sections under all conditions of use.

The antenna sections are actuated by being connected with a driving member in the form of an elongate, exible strip which is preferably formed of an insulating material such as a synthetic libre-forming polymeric amide, forms of which are known commercially as nylon, the said member being axially driven by friction Wheels or rollers between which the member passes, and which the member traverses in its axial movement. When the antenna sections are retracted or nested in each other, the driving member extends through a novel sheath which, in the embodiments of the invention illustrated herein, is formed of small-diameter soft aluminum tubing, arranged `so that the sheath or tubing and the nylon driving member within it may be bent or formed without the use of tools, to fit various different spaces which may be available for it to occupy. Thus the antenna may be readily adapted for use in different locations on a car, and is universal in application to all types and makes of cars.

In one illustrated embodiment of the invention, the power transmission between the nylon driving member and motor comprises a pair of shafts extending side by j curely grip the member.

side and having juxtaposed worm wheels which receive between them and engage a worm carried on the motor spindle. The shafts also carry juxtaposed grooved friction wheels which engage opposite sides of the nylon driving member, and the said member has a novel, flattened, substantially hexagonal cross-section such that it closely fits the walls of the grooves in the friction wheels. The shafts are movable toward and away from each other, and are urged together by a yieldable resilient means such as an extension spring, to cause the friction wheels to engage the nylon driving member under continual pressure. By the provision of the motor-driven worm and the pairs of worm wheels and pairs of grooved friction wheels, together with the flattened hexagonal cross-section of the driving member, a small and compact yet reliable drive is had between the electric motor and the antenna sections, characterized by an absence of slippage between the friction wheels and the nylon member.

In another illustrated embodiment of the invention, the shafts of the power transmission are inclined toward each other, that is, they extend in convergent directions, and the centers of the worm wheels are spaced apart a greater distance than the centers of the driving pulleys which engage the nylon driving member. Also, the diameters of the worm wheels are larger than the diameters of the driving pulleys whereby a mechanical advantage or ratio is provided. In this embodiment of the invention, instead of the shafts being yieldably urged toward each other, the friction pulleys are each formed of two halves which are axially movable relative to each other and which are normally yieldably urged toward each other to cause an effective gripping of the nylon driving member.

In yet another embodiment of the invention the nylon driving member is provided on one side with transverse teeth along its length, and one of the driving wheels is provided with cooperable teeth whereby a rack and pinion drive is produced, to effect a positive actuation of the antenna sections.

In the several embodiments of the invention illustrated the nylon driving member is connected with one of the telescopic antenna sections by a novel structure comprising a metal sleeve which encompasses adjacent ends of the antenna section and driving member, the said sleeve being crimped to provide internal nibs which are embedded in the member, thereby causing the sleeve to se- Also the sleeve is crimped to cause other portions to enter a recess or groove provided in the side of the antenna section. Thus a sturdy and extremely economical connection is established between the antenna section and nylon driving member. By the above organizations there is thus provided a powerdriven extendable and retractable telescopic antenna which is extremely economical to manufacture, is compact and small in size, positive and reliable in operation, and which may be readily adapted to fit various spaces available for it to occupy.

Other features and advantages will hereinafter appear.

In the accompanying drawings:

Figure l is a fragmentary side view of the improved telescopic antenna of the invention, part of the antenna being shown in elevation and part being shown in section.

Fig. 2 is a horizontal section taken on line 2-2 of Fig. l.

Fig. 3 is a fragmentary vertical section taken on line 3 3 of Fig. 2.

Fig. 4 is an enlarged fragmentary horizontal sectional view, taken through the driving member and the friction wheels engaging the same.

Fig. 5 is a fragmentary elevational View, enlarged, of the improved connector means and adjacent ends of the driving member and antenna section attached thereto.

Fig. 6 is an elevational view like Fig. 5 but looking in the direction of the arrows 6-6 in Fig. 5.

Fig. 7 is an elevational View of the complete antenna, showing the bendable sheath for the exible driving member.

Fig. 8 is a schematic diagram of the circuit of the antenna.

Fig. 9 is a view partly in elevation and partly in vertical section, showing a modified form of antenna of the present invention.

Fig. is a vertical sectional view taken on line 10-10 of Fig. 9.

Fig. 1l is a horizontal sectional view on line 11-11 of Fig. 10. d

Fig. l2 is a fragmentary sectional view on line 12--12 of Fig. 11.

Fig. 13 is a horizontal sectional View like Figs. 2 and 11, but showing a different actuating mechanism illustrating another modification of the invention.

Fig. 14 is a fragmentary elevational view looking in the direction of the arrow 14 of Fig. 13.

Fig. 15 is a fragmentary axial sectional View of a friction wheel illustrating yet another embodiment of the invention.

Fig. 16 is an end elevational view of the assembly of Fi 15.

gFig.V 17 is a transverse sectional view taken on lnie 17-17 of Fig. 15, and

Fig. 18 is an axial sectional view of another modified driving wheel made according to the invention.

Referring to Fig. 1, the improved telescoping antenna of the present invention as illustrated comprises a tubular housing or casing 20 in which a plurality of telescopic antenna sections 21 may be disposed, the sections 21 being extendable upwardly to enable them to project a considerable distance above the casing 20 and in alignment therewith, so as to constitute a conducting staff or standard for intercepting radio waves.

The casing 20 and telescoping sections 21 may have any suitable desired length; they are shown in Fig. l as being broken away intermediate their ends for purposes of convenience of illustration. The sections 21 are illustrated as being four in number, including an innermost section 22 which is in the form of a solid rod, slidable in a tubular section 23 which latter is slidable in another tubular section 24, the section 24 being in turn slidable in a tubular section 25 which is anchored to the casing 2li. While a total of four telescoping sections have been shown, the invention is applicable to telescoping sections of greater or lesser number.

The tubular casing 20 at its upper end engages and surrounds a cylindrical portion 26, of reduced diameter, of an insulating bushing 27, and is secured to said reduced portion by drive pins 28. The upper end of the insulating bushing 27 engages a washer 29 which is preferably of resilient rubber and which in turn engages the underside ofthe cowling, fender or other supporting surface 30 of the automobile, which surface has an aperture 31 therein through which the antenna sections 21 may extend. A second insulating bushing 32 is provided, engaging at its lower end a resilient rubber washer 33 having a depending ange 34 by which it is centralized in the aperture 31 of the cowling 30, the washer 33 engaging the upper or outer surface of the said cowling. The insulating bushing 27 is screwed on an externally threaded sleeve 35 which passes upward through the

washers

29 and 33, and through the insulating bushing 32. The upper end of the threaded sleeve 35 carries a knurled nut 36 by means of which the insulating

bushings

27 and 32 are secured together and caused to tightly clamp between them the cowling 30.

The outermost antenna section 25 extends downwardly through the casing 20 and is substantially coextensive therewith, the lower end of the section being threaded and screwed into an insulating bushing 37 press-fitted in an upstanding tubular metal iitting 38 having external threads carrying a pair of

nuts

39 and 40. The lower end of the casing 2t) is secured to the nut 39, and the nut 40 is used to lock the casing and nut 39 to the fitting 38. The tubular fitting 38 is secured to and projects upwardly from a top plate 41 which forms part of a housing 42 for the driving or power transmission between the antenna sections 21 and an electric motor 43. The motor 43 is mounted on a large diameter, tubular depending portion 44 of the housing 42.

In accordance with the present invention a novel and improved, efficient and reliable transmission is provided between the electric motor 43 and the antenna sections 21, whereby the antenna-to-ground capacity is held to a low, uniform value, and whereby power losses are low while at the same time a small and compact assemblage is had, so that the antenna is adaptable to all available spaces inV a car. This transmission comprises a driving member 45 connected to the innermost antenna section 22, the said member being in the form of a flexible strip of plastic insulating material, preferably a synthetic fibre-forming polymeric amide such as nylon. As shown in Figs. l through 4, the nylon member 45 is relatively at and of irregular hexagonal cross-section, having relatively

narrow sides

46 and 47 disposed opposite each other, and having pairs of

wider sides

48a, 481;, 49a and 49h, disposed between the

sides

46 and 47. The sides 48a and 48h, transversely of the strip 45 extend in convergent directions, as do the sides 49a and 4911. The novel transmission of the present invention also cornprises oppositely driven friction rollers or wheels 50, having V-grooves 50a adapted to receive and engage .the pairs of wide sides of the member 45 as clearly shown in Fig. 4, thereby to minimize slippage on the member.

The friction wheels 50 are rigidly secured to and carried on shafts 51, which shafts also carry worm wheels 52, aiiixed to the shafts and engaging opposite sides of a worm 53 which latter is mounted on the spindle 54 of the motor 43. The shafts 51 are carried in sphericalshaped bearing blocks 55, preferably formed of metalgraphite composition, which blocks are pivotally mounted in a bearing support 56 located in the housing 42. The bearing support 56 has a base portion 57 to which is secured a bearing block 58 having slots 59 which receive and rotatably carry the shafts 51. Collars 60 are carried by the shafts 51 to cooperate with the friction wheels 50 and worm wheels 52 for limiting endwise movement of the shafts.

Adjacent the friction wheels 50 the shafts 51 have grooves 61 receiving the hooked ends of a coil extension spring 62, by which the shafts 51 are urged toward each other to cause the friction wheels 50 to press against the nylon driving member 45 at all times. Referring to Figs. 2 and 3, the slots 59 in the bearing block 5S, together with the pivotal mounting of the spherical bearing blocks 55, enable the shafts 51 to be swung away or towards each other within limits, thereby enabling the spring 62 to cause the friction wheels 50 to grip the driving member 45.

In accordance with the invention, a novel means is provided for housing the iiexible nylon member 45 whereby the antenna may be accommodated in various different spaces which might be available in different types and styles of automobiles. Referring to Figs. 1 and 7, this housing means comprises an elongate tubular sheath 63, preferably formed of aluminum tubing, which is adapted to receive and contain practically the entire length of the nylon member 45 when the telescopic antenna sections 21 are in retracted positions. The sheath 63 is connected to a hollow fitting 64 by a threaded nut 65, which may bear against a flare 66 of the sheath as shown in Fig. l. The fitting 64 is secured to, and depends from the bottom of the housing 42, and the nylon driving member 45 extends through the iitting and into the sheath 63 as shown.

Referring to Fig. 7, the sheath 63 may be bent into a coil as indicated, or may be extended straight out as shown by the dot-and-dash position 67, or may be given any other shapes, to accommodate it to the spaces available in the automobile. Since the sheath 63 is formed of soft aluminum tubing, and since the nylon member 45 is flexible, the member and sheath may be readily bent by hand and without the use of tools. While the sheath 63 is shown as having a large-radius bend 68 a short distance from the fitting 64, it should be understood that the sheath could be made to extend straight downward from the tting a greater distance than that shown, prior to being bent, or could have many other different shapes to t all spaces which may be available. It will be noted that, due to the nylon member 45 being electrically non-conducting, its presence in the sheath 63 (which is grounded by the casing 42) does not alter the antenna-to-ground capacity, nor increase lsuch capacity undesirably.

Referring to Figs. 5 and 6, according to the invention a novel connection means is provided between the innermost antenna section 22 and the end of the nylon driving member 45. This connectioncomprises a fitting "69 which is rigidly secured to the lower extremity of the antenna section 22, and which has a portion 70 of Vreduced di'ameter, provided with an annular groove 71. A sheet metal sleeve 72 is provided, having a portion 73 encompassing the reduced-diameter portion 7 0 of ther liitting 69,the sleeve 72 also receivingnthe upper end portion 45a of the element 45. The sleeve 72 is crimped to provide a rib 74 which extends into the groove 71 of the fitting 69, thereby securely locking the sleeve to the fitting. Also the sleeve 72 is crimped at a plurality of points 75 to provide nwardly projecting nibs which displace the material of the member and become embedded in the member. Thus the sleeve 72 is securely fastened to the member 45 and provides an effective connection or union whereby the driving member is connected to the antenna section 22.

By the above construction I have provided a simple, economical effective and reliable, driving mechanism or transmission between the motor 43 and the antenna sections 21, which mechanism enables an advantageous, small and uniform electrical capacity to be obtained between the antenna and ground, provides for reliable extension and retraction of the antenna sections, while at the same time being compact and small in size. When the motor 43 is energized, the worm 53 will drive the worm wheels 52 in opposite directions, causing the friction wheels to either raise or lower the nylon driving member 45 according to the directions in which the Wheels rotate. Because of the V-grooves 50a in the wheels 50, and the generally at shape of the driving member 45, with hexagonal cross section as indicated, an efficient friction drive is provided which results in the antenna sections being reliably raised or lowered without slippage. The extension spring 62 maintains a uniform pressure between the driving member 45 and the friction wheels 50 to aid in effecting this result. With the above organization, if it should be desired to actuate the antenna sections 21 by hand without energizing the motor 43, this may be done at any time, since by the application of sufficient force the driving member 45 may be made to slip between the friction wheels 50. The tension of the spring 62 is adjusted to enable such slippage to occur, and yet to prevent slippage during driving of the antenna sections by the wheels 50.

As shown in Fig. 8, the motor 43 has an armature 76 connected to a ground 77 and also to the common point of a double field winding 78 which latter is in turn connected with

stationary switch contacts

79 and 80. A movable switch contact 81, cooperable with the

contacts

79 and 80, is connected with a battery 82, which is also grounded at 83.

To provide for electrical connection to the antenna sections 21 a tubular fitting 84 is provided in the side of the casing 20, having an insulating bushing carrying a spring urged contact 86 engageable with the exterior of the outermost antenna section 25. The contact 86 is connected with a lead wire 87 which is shielded by a iiexible metal sheath 88 secured to the fitting 84.

An antenna made according to a modification of the invention is shown in Figs. 9 through l2. This antenna comprises a plurality of telescoping sections 89 the innermost section 90 of which is secured to an elongate flexible nylon driving member 91 similar to the member 45. The outermost antenna section 92 is carried by a pair of insulating bushings 93 and 94 which engage respectively the upper and lower extremities of the antenna section. The bushing 94 seats against an inturned ange 95 of a tubular casing 96 the upper extremity of which receives and is secured to a sleeve 97 passing through an aperture 98 in a cowling 99. The insulating bushing 93 is press-fitted in the upper end of thesleeve 97, and the said end of the sleeve is externally threaded and carries a nut 100 which bears against an insulating spacer or collar 101 resting on a resilient Hat rubber washer 102 engaging the outer surface of the cowling 99. The inner or undersurface of the cowling 99 is engaged by a metal sleeve 103 which has an inturned ange 104 engaging the extremity of the casing 96. It will be seen that tightening of the nut 100 causes the cowling 99 to be clamped between the sleeve 103 and the resilient rubber washer 102. Also, it will be noted that by engagement of the sleeve 103 with the cowling or fender 99 the casing 96 and the sleeve 92 carried thereby are grounded to the said cowling or fender. Electrical contact is established to the antenna sections 89 by means of a resilient contact nger 105 which extends through an aperture 106 in the outermost antenna section 92 and engages the next antenna section 107 (the antenna section slidably carried in the outermost antenna section 92) The resilient contact finger 105 is insulatedly carried by an insulating block 108 secured in a metal shell 109 which is attached to the casing 96.

In the embodiment of the invention shown in Figs. 9 through 12, the novel and improved actuating means for the antenna sections 89 include a modified transmission,

6 and also a unique electric motor, designated 110, which is arranged in such a manner to be extremely compact, and to occupy very little space.

Referring to Figs. l0 and l1 the transmission between the motor 110 and the nylon member 91 comprises a pair of friction wheels 111 having grooves 112 in which the member 91 is received.

Each of the wheels 111 comprises two halves 113 and 114, the halves 113 having hubs 115 which are press-fitted on shafts 116 against shoulders 117 thereof, the hubs 115 being slidably received in the bores of the wheel halves 114, which bores are made sufficiently large for this purpose. Each wheel half 113 has pins 113:1 which enter recesses 117 inthe cooperable wheel half 114, thereby keying the wheel halves together against relative rotation. The shafts 116 have reduced end portions 118 having external screw threads, and having smooth parts of hexagonal shape as shown, the screw threads accommodating nuts 119 and the hexagonal-shaped parts carrying lock washers 120 and friction star washers 121, the latter urging together the wheel halves 113 and 114 in a manner tending to cause the V-groove 112 between the halves to have a minimum width.

The shafts 116 are rotatably carried in bearing bushings 122 which are preferably formed of nylon, the said bushings being press-fitted in a frame 123 which is carried by a plate 124 forming part of a housing 125 enclosing the transmission and the upper portion of the motor 110. The frame 123 has a second set of nylon bearing bushings 126 in which the shafts 116 rotate, and between the

bushings

122 and 126 the shafts 116 have worm wheels 127 engaging opposite sides of a worm 128 which latter is carried on the spindle 129 of the motor 110.

The shafts 116 extend in convergent directions, the centers of the worm wheels 127 being further apart than the centers of the friction wheels 111, and the worm wheels have a larger diameter than the friction wheels. By this organization an advantageous mechanical reduction is effected, since not only is a mechanical advantage obtained between the worm 128 and worm wheels 127, but also a mechanical advantage is obtained between the worm wheels 127 and the friction wheels 111.

Referring to Fig. l0, the motor 110 has a novel, very compact construction whereby it requires a relatively small amount of space. In accomplishing this, the motor is provided with a tubular or hollow field core 130 carrying annular eld coils 131, the ends of the core 130 being connected with

extensions

132 and 133 constituting pole pieces for the motor armature 134. The motor shaft 129 extends through the hollow field core 130 and is rotatably carried in a bearing block 135 which is preferably of spherical shape, the said bearing block being retained in the core 130 by

rings

136 and 137, the latter ring being spring-urged by a helical compression spring 138 engaging the end Wall 139 of the motor casing 140. The end wall 139 has a depending tubular portion 141 which in internally threaded to carry an adjusting screw 142, and a ball bearing 143 is disposed between the end of the spindle 129 and the screw 142 to provide a wear-resistant anti-friction thrust bearing. A second thrust bearing is provided for the other end of the spindle 129, and comprises a ball bearing 144 carried in a sleeve 145 which is threaded to hold an adjusting screw 146, the sleeve being secured to the upper wall 147 of the casing 125.

As in the embodiment of Figs. l through 8, the iiexible nylon driving member 91 for the antenna sections extends through a flexible tubular sheath 148, which may be bent into various shapes as required to fit available space.

Another modified form of transmission between the motor and telcscoping antenna sections is shown in Figs. 13 and 14. This transmission comprises a flexible driving member 149, which is preferably formed of nylon, having a smooth side 150 and having an its opposite side transversely extended teeth 151. The member 149 passes between a smooth-surfaced wheel or roller 152 and a toothed wheel 153, the periphery of the latter engaging the teeth 151 of the member. The roller 152 rotatably carries a bushing 154, which is preferably of nylon, fixedly carried by a shaft 155 which is mounted in a bearing frame 156 secured to a transverse wall or plate 157 of a casing 158. The toothed wheel 153 loosely fits on a reduced portion 159 of a shaft 160, which latter is mounted in nylon bearing bushings 161 and 162 carried by the bearing frame 156. Between the bushings 161 and 162 the shaft 160 has a worm wheel 163 engaged over the nut 184 to prevent loosening of the latter.

and casing shown in Figs. 10 and l1.

A modified form of friction driving Wheel for the

nylon driving members

45 and 91 described above, is shown in Figs. 15, 16 and 17. The wheel 171 shown in these figures comprises a pair of

halves

172 and 173, the wheel half 172 having a hub 174 which is press-fitted on a knurled portion 175 of reduced diameter, of a shaft 176. The wheel half 173 has an enlarged bore by which vit slidably receives the hub 175, and has internal spines 177 received in grooves 178 in the hub 174 whereby the wheel halves are keyed together against relative turning.

The wheel halves 172 and 173 have sloping faces 179 and 180 which together constitute a tl-groove for receiving the nylon driving element. Also, the Wheel half 173 has recesses 181 receiving the arms 182 of a spring star washer 183, which latter is engaged by a nut 184 threaded on a reduced threaded extension 185 of the shaft 176. As shown in the figures, the shaft extension 185 is peened The shaft 176 and Wheel 171 may obviously replace either of the shafts 116 and Wheels 111 shown in Fig. l1.

Fig.18 illustrates a modiiied frictionally-driven driving wheel made according to the invention, adaptable for use with any one of the nylon driving members described. This wheel comprises a circular body 186 which, to adapt it to the nylon strip or member 149, may have teeth 187 on its periphery for engaging the toothed side of the member 149, the body 186 being loosely carried on a reduced portion 188 of a shaft 189 which latter is driven by the electric motive means. The reduced portion 188 of the shaft also carries a spring star Washer 190 which bears against one side of the body 186 (being accommodated in a recess thereof), and rigidly carries a circular plate or disk 191 having a beveled edge 192' engaging a beveled surface 193 in the other side of the body 186. Thus the plate 191 and body 186 constitute in effect the plates of a friction clutch being yieldably held together by the star washer 198 and engaging eachother along the beveled surfaces 192A and 193. The disk 191 is rigidly4 secured to the shaft portion 188 by a pin 194 as shown. By virtue of the inclined surfaces of the

bevels

192 and 193,2. wedging action is provided between the disl:

19.11 andthe body 186, and therefore the star Washer 19t) need not exert a very great force in order to prevent slippage of the .body 186 With respect to the shaft 189 during driving of the nylon member 149. While the body 186 is shown as having teeth, obviously it may have a smooth periphery, with or without a groove, to adapt it to other forms of nylon driving members.

Thelshaft 189 and Wheel carried thereby may obviously be substituted for the shaft 161) and wheel 153 shown in Fig. 13.

Variations and modifications may be made within the scope of this invention and portions of the improvements may be used Without others.

I claim:

1. In an antenna having an elongate, longitudinally extendable and retractable section and a driving strip connected to actuate said section, means for driving said strip. comprising a unitary shaftya pulley having a pair of pulley halves both carried on the said shaft, having substantially opposed surfaces respectively which are engageable with different surfaces of the strip; and yieldable means comprising a resilient washer, normally urging the pulley halves toward each other and against the said surfaces of the strip.

2. ln an antenna having an elongate, longitudinally extendable and retractable section and a friction driving strip connected to actuate said section, means for driving said friction strip comprising a pair of unitary shafts; a pair of pulleys carried by each of said shafts and each having pulley halves having substantially opposed surfaces respectively which are engageable with different surfaces of the strip; and yieldable means cornprising a resilient washer, normally urging the pulley halves of each pair toward each other and against the said surfaces of the strip.

3. In an antenna having telescoping sections and a friction driving strip connected to actuate one of said sections, means for driving said friction strip comprising a shaft; a pair of pulley halves on the shaft, having substantially opposed surfaces respectively which are engageable with different surfaces of the strip, one of said pulley halves having a hub and the other half having an enlarged bore receiving the hub; a tongue-and-groove connection between the pulley halves, for keying the halves together; and yieldable means comprising a resilient washer, normally urging the pulley halves together and against the said surfaces of the strip.

4. In an antenna having an elongate, longitudinally extendable and retractable section and a driving strip connected to said section to actuate the same, means for axially advancing and retracting said strip, comprising a pair of juxtaposed drive wheels engaging opposite sides of the strip; shafts extending in convergent directions, carrying said wheels respectively; worm wheels carried by the shafts respectively, the centers of the worm wheels being further apart than the centers of the drive wheels, and said Worm wheels having a greater diameter than the drive wheels; and a single worm extending between and engaging the worm Wheels for turning the Wheels in opposite directions.

5. In an antenna having an elongate, longitudinally extendable and retractable section, a driving element comprising a strip connected at one end to said section to actuate the same; and juxtaposed friction rollers having V- grooves, engaging opposite sides of Said strip for axially moving the same, said strip having pairs of surfaces, the surfaces in each pair extending in convergent directions transversely of the strip and engaging the opposed Walls of the V-grooves of the rollers.

References Cited in the tile of this patent UNITED STATES PATENTS Number Name Date 1,343,005 `Sauvage .lune 8, 1920 1,671,796 Tracey May 29, 1928 2,209,736 Livingston July 30, 1940 2,287,674 Fairbanks lune 23, 1942 2,294,362 Brach Sept. 1, 1942 2,299,785 Barrett Oct. 27, 1942 2,313,652 Lyman Mar. 9, 1943 2,319,860 Hann May 25, 1943 2,327,163 Barrett Aug. 17, 1943 2,329,329 Brach etal Sept. 14, 1943 2,365,886 Lehmann Dec. 26, 1944