US2778017A

US2778017A - Portable antenna

Info

Publication number: US2778017A
Application number: US332225A
Authority: US
Inventors: Dorcsjak Charles
Original assignee: MARJO TECHNICAL PRODUCTS CO
Current assignee: MARJO TECHNICAL PRODUCTS CO
Priority date: 1953-01-21
Filing date: 1953-01-21
Publication date: 1957-01-15
Anticipated expiration: 1974-01-15

Description

Jan. 15, 1957 c. DORCSJAK 2,778,017

PORTABLE ANTENNA Filed Jan. 21, 1955 2 Sheets-Sheet l IN V EN TOR. (304 355 fioecx: JAK

A 7' TOR/YE Y5 Jan. 15, 1957 c. DoRcsJAK I 2,778,017

PORTABLE ANTENNA Filed Jan. 21, 1955 2 Sheets-Sheet 2 PORTABLE ANTENNA Application January 21, 1953, Serial No. 332,225

2 Claims. (Cl. 343--823) This invention relates to an improved portable indoor antenna for but not necessarily restricted to association with, a television receiver.

Summarized briefly, my invention is an antenna that includes a housing having a manually rotatable shaft journaled therein, a pair of spaced, conductive tapes wound around the shaft and to be wound upon or unwound from the shaft responsive to rotation of the shaft in opposite directions. The tapes have free ends extending through openings formed in opposite walls of the housing, and thus, when the shaft is rotated in one direction, the free ends of the tapes, constituting antenna arms, are projected outwardly from the housing in opposite directions to selected lengths. Conversely, when the shaft is rotated in a tape-winding direction, the antenna arms can be retracted until they are disposed entirely within the housing, with the exception of small, flanged tips on the free ends of said arms.

A well known type of indoor television antenna in widespread use today includes telescopic arms of rod material. Even when said arms are telescoped to their maximum extent, they remain of substantial length, presenting an unsightly appearance and making inconvenient the handling and storage of the antenna.

One important object of the presentinvention is to provide an antenna in which the extensible arms are fully retractile into a small, box-like housing.

Further, a conventional indoor antenna of the type noted above requires that the antenna arms be gripped manually to extend or retract them. A secondimportant object of the present invention is to provide for extension or retraction of the antenna arms by rotation of a knob, which knob is fully insulated from the conductive tapes that form the arms, so that effects of body capacitance of the operator during adjustments of the arms are eliminated.

tion, the claims appended thereto, and from the annexed drawings in which like reference characters designate like parts throughout the several views, and wherein:

Figure 1 is a perspective view of a portable antenna formed in accordance with the present invention;

Figure 2 is an enlarged sectional view taken substantially on line 22 of Figure 1;

Figure 3 is a sectional view taken substantially on line 3-3 of Figure 2;

Figure 4 is a sectional view on line 44 of Figure 3;

Figure 5 is a fragmentary perspective view showing the means for maintaining an electrical connection between the antenna arms and a lead-in cable; and

Figure 6 is a perspective view showing the antenna as it appears when positioned to receive ultra-high frequency signals.

The illustrated antenna of the present invention includes a hollow, rectangular, box-like housing designated generally at 10 and formed of molded plastic or other electrically insulative material. The housing 10 has a flat, rectangular base 12 and a cover 14 formed with a peripheral, depending flange that defines side walls and end walls of the housing. Within the several corners of the cover, enlargements 16 are formed, "said enlargements being disposed in contact withthe base 12 and having threaded openings receiving connecting screws 18 that extend through smooth walled openings formed in the Yet another object is to provide an antenna construe tion in which both the antenna arms are adjusted as to length simultaneously, and to the same extent. It is a fundamental principle in the construction of television antennae that both arms should be of equal length at all times. Obviously, a telescopic type antenna in which one arm is manually adjusted independently of the other arm makes it difiicult to retain the arms at lengths equal to one another, in selected positions of adjustment.

Still another important object of the invention is to provide a portable antenna device which can be adjusted bodily to a position in which it will receive efiiciently ultra-high frequency signals. Thus, it is proposed that the antenna will be well adapted to receive not only very high frequency signals, but also signals in the ultra-high frequency range.

A still further object of importance is to provide an antenna formation which, though possessing the several desirable features noted above, is capable of manufacture at relatively low cost, is trouble free in operation, and attractive in appearance.

Other objects will appear from the following descripcorners of the base. Thus, the cover is detachably connected to the base, and can be readily removed whenever access to the interior of the housing is desired.

Upon the base, there are secured a plurality of shaft supports, said shaft supports including end supports 20 near and spaced from the housing end walls 19, and a middle shaft support designated generally at 22 (Figur 2). The middle shaft support is disposed in the space between the end supports, and is spaced equidistantly from the respective end supports.

Each of the

supports

20, 22 is formed of a lower block and an upper block, the lower blocks of all three supports being identically formed and being designated by the reference numeral 24. The lower blocks are of solid formation, and are of rectangular, relatively elongated shape. Each lower block has a threaded recess formed in the underside thereof, adjacent its respective ends, andconnecting screws 26 are engaged in said recesses, said connecting screws extending through smooth. walled openings formed in the base 12. Thus, the several lower blocks 24 are fixedly connected to the base 12, during the assembly of the device.

In the upper surface of each lower block 24, medially between the opposite ends thereof, a transversely disposed, half-round, bearing recess 28 is provided, the

several recesses 28 being aligned coaxially, for a purpose to be made presently apparent.

The end supports 20 have upper blocks 30, that overlie the lower blocks of said end supports, While the middle support 22 is provided with an upper block 32, which differs slightly in construction from the upper blocks 30. The upper blocks 30 have, in their undersides, transversely disposed, half-round, bearing recesses opposing the recesses 28 of their associated lower blocks, so as to cooperate with said associated lower blocks in forming transverse bearing openings in the end supports 20.

The upper block 32 also has, in its underside, a, transversely extended bearing recess half-round in cross sectional configuration, but the recess of the block 32 is slightly greater in respect to the radius thereof than are the recesses of the blocks 30. The purpose of this arrangement is to provide a clearance space for a pair of In any event, it is seen that the construction illustrated and described provides a plurality of shaft supports, all of which have transverselydispos'ed, coaxially aligned bearing openings. It may be noted, in this regard, that after the upper blocks .are positioned uporttheir associated lower blocks, they are fixedly securedthereto by elongated screws 34 (Figure .4), said screws 34 extending downwardly. through smooth walled openings formed in the opposite ends of the respective upper blocks, and being threadedly engaged in aligned, cornplementarily threaded recesses extending. downwardly from the top surfaces of the lower blocks 24.

Journaled in the several bearing openings of theshaft supports is a shaft 36 of electrically insulative material, one end of said shaft projectingthrough an opening formed in one end wall of the housing, and 'being fitted with a knob 38. The knob lad-issecured to theshaft 36 in any suitable manner, for .the purpose of rotating-the shaft whenever antenna adjustments are .to be effected. The projecting end of the shaft can, for example, be of half-round formation, with the knob-38 having anomplementary, half-round recess receiving the projecting portion of the shaft.

.In the-spaces defined between the middle shaft support and the respective end shaft supports, .coiled tapes 40 of conductive materialaare disposed. -The tapes- 4%) are of spring steel, in a preferred embodiment ofthe invention, and are concavedtransversely, so :as to cause any portion of the tape that is'unwound to .extend as a rigid member, this construction being nevertheless well adapted to permit the tapes to be wound or unwound, as necessary.

.As will be noted'from Figure 3, the tapes are relatively wide as compared to the thicknesslthereof, it having been found that this permits better reception, since therev is more surface area than --.is obtained by theme .ofzmetal tubular rods 'or the like.

.Both of the coiled tapes 40 .are secured to the shaft 36 at theirinner-ends, and-to illustratesonewmanner.in which the inner-ends of the coiled -tapes can :be secured to the shaft, there is shown, .in :Figure 3,. ailongitudinal slot 42 formed in the shaft SdfOreach'coil. The slots 52 extend diametrically through the :shaft, opening .upon diametrically opposite sides of 'thelshaft, :andzextending through each slotis the inner end-f :eachtapegsaidsend being-bent about the shaft rafter: being passed through the slot. Thereafter, the tfiPBrxiS coiled/:about the shaft, and is Wound or unwound'frornrthe shaftmesponsiveto the rotation of the shaft in opposite directions. Inthe side Walls of'thei'housing at-:opposite sides-of the shaft 36, I form slot-like apertures d4, said ;apertures being spaced a substantial :distance above the base 12, adjacent the top portion.-of. the=;cover 14. Thisflocation of the :apertures is desirable, :sincesa'id :apertures are thus disposed above .theperiphery of eachtape; when-the tapeis fullywound. .-As a.result,-when'the-free ends of the respective tapes .are extended through the apertures 44 in the manner shownintheyseverztl figures'of'the-drawing, unwinding of the tape coils will ihe effective to extend :said. free ends of the tapes upwardly and-outwardly from the opposite side walls=ofthehousing through'which the tapes project.

As will be::readily observedfrom Figures 1, 4, and'6, :the projecting, free ends of the/tapes 4lihave small, downturned' lips 46, said lips definingabutments which prevent-complete retraction ofthe *tapes into the housing, by reason .of engagement ofthe abutments against the side walls of the housing in which the apertures id-are formed. However, with the lips 46 engaging said side walls, the free .ends of the 'tapes that constitute the .antenna-arm.s,:are substantially invisible, and the overall bulk of the device is-s'ubstantially defined =by tl1--SlZ of -thehouslng alone.

Itshou'ld-be 'noted' that both of the tapes are coiled upon the-shaft-36 in" the sam'e'direction, and therefore, both tapes will be simultaneously wound or simultaneous- 1y unwound, depending upon the direction in which the shaft is rotated.

That part of the shaft 36 that extends through the bearing opening of the middle shaft support 22 is provided with a pair of longitudinally spaced circumferential contacts 50 to which leads 48 are soldered and which are severally connected to the shaft-attached inner ends of the coiled tapes. The contacts 50 are shown to particular advantage in Figures 3, 4, and 5. Each contact 591s formed as an arcuate piece of metal material, the ends of which are clinched into or otherwise embedded in the material of the shaft.

Engaging each contact 50 is a brush 52, said brushes being of electricallyconductive material. The purpose of forming the half-round recess provided in the underside of the upper block 32 of the middle support 22 to a greater diameter than the corresponding recesses of the upper blocks St), is to provide a clearance space for said brushes, this construction being best shown 1n Figure 4.

The brushes 52 are arcuate and conformably engage the contacts 50 in anyposition to which the shaft 36 1s rotated, due to the length of the contacts 50. The

brushes 52 have ends which are attached permanently to leads-6140f a lead-in cable 56, that extends out of the housingzthrough a slot 58 formed in one side wall of the coves-14. .The underside of the middle upper block 32 is secured as necessaryto accommodate the lead-in cable 56, and the. cable isto be connected to a television receiver or the like, not shown.

In Figure 6, -I have shown the antenna device turned bodily out of theerect position thereof shown 1n F1gure 1, to a reclining position in which that end wall. opposite the-knob 38 rests .upon a support, such as an associated televisionreceiver. In this position ,ofrthe antenna, the arms 40 are disposed horizontally, and it has been found that .this arrangement results in an efficiently operating ultra-high frequency antenna, this being considered to be an important characteristic of the inventlon.

-It is also'thought-to be an important characteristic of the construction that the device is attractive, and when not in use, takes up a minimumof space, due to the com- .plete retractibility of the. antenna arms. At the same time, a marked degree ofefliciency is obtained dur ng use.

-It isralso. believed important to note that the knob 38 and/or the antenna arms can be calibrated as to length, channel ,number, Wave length, etc. This is believed to be sufiiciently obvious as not to require special illustration, and it isicontemplated that in commercial embod1- ments. of the device, such calibrations might well be-desirable.

..It.is also thought worthy of note that dimensions, materials, etc., might be varied within the scope of the appended .claims, and. the antennacould, for example, be of any suitable material such as steel, Phosphor bronze, plastic coated with electrically conductive material, and the like.

.It is believed apparent that the invention is not necessarilyconfinedtothe specific use or uses thereof described .above,.since it may be utilized for any purposeto WhlCh it .may .besuited. Nor is .the inventionto be necessarily limited to. the specific :construction illustrated and described, since suchiconstruction is onlyintended-to be illustrative of the-principles of operation and the means presently devised tocarry out said principles, .it being considered .that the. invention comprehends any minor change iDJCOHStLUCtlOB that maybe permitted withlnthe .seopeofthe appended-claims.

walls. depending from said top Wall, ,saidwalls having.

lower edges removably resting ,upon theupper. surface. of the .base,means .removably securing the cover to the base, end supports secured to and rising from the upper surface of the base near to and spaced from the end walls of the cover, a middle support secured to and rising from the upper surface of the base between and spaced from said end supports, said supports comprising lower blocks having upper edges provided with longitudinally aligned semi-circular bearing recesses and upper blocks having lower edges resting upon the upper edges of the lower blocks, said lower edges having semi-circular bearing recesses registered with the bearing recesses of the lower blocks, a non-conductive shaft journaled in the registered bearing recesses, one of said cover end walls having an opening aligned with the bearing recesses and said shaft having an end portion extending out of the cover through said opening, a knob on said end portion, each of the cover side walls having a slot in line with the space between an end support and the middle support, the slots being located on a level above said shaft, a flexible resilient conductive tape extending through each of said slots, the tapes having inner ends wound around and secured to the shaft between the middle support and related end supports and outer ends, stops on the outer ends of the tapes for engagement with related side walls of the cover, the inner ends of the tapes being wound in the same direction on the shaft, and contact means connected to the inner ends of the tapes and arranged to be con nected to a lead-in cable.

2. In a portable antenna, an insulative flat base having ends and sides and an upper surface, a removable insulative cover comprising a top wall and end walls and side walls depending from said top wall, said walls having lower edges removably resting upon the upper surface of the base, means removably securing the cover to the base, end supports secured to and rising from the upper surface of the base near to and spaced from the end walls of the cover, a middle support secured to and rising from the upper surface of the base between and spaced from said end supports, said supports comprising lower blocks having upper edges provided with longitudinally aligned semi-circular bearing recesses and upper blocks having lower edges resting upon the upper edges of the lower blocks, said lower edges having serni-circular bearing recesses registered with the bearing recesses of the lower blocks, a non-conductive shaft journaled in the registered bearing recesses, one of said cover end walls having an opening aligned with the bearing recesses and said shaft having an end portion extending out of the cover through said opening, a knob on said end portion, each of the cover side walls having a slot inline with the space between an end support and the middle support, the slots being located on a level above said shaft, a flexible resilient conductive tape extending through each of said slots, the tapes having inner ends wound around and secured to the shaft between the middle support and related end supports and outer ends, stops on the outer ends of the tapes for engagement with related side walls of the cover, the inner ends of the tapes being wound in the same direction on the shaft, and contact means connected to the inner ends of the tapes and arranged to be connected to a lead-in cable, said contact means comprising a pair of longitudinally spaced circumferential arcuate contacts fixed on said shaft within the registered bearing recesses of said middle support, a pair of arcuate brushes conformably and severally engaged with said contacts within the registered bearing recess of said middle support, leads severally connecting the contacts with the inner ends of the tapes, and leads on the brushes for connection to a lead-in cable.

References Cited in the file of this patent UNITED STATES PATENTS 2,565,661 Lidz Aug. 28, 1951 2,568,465 Scott Sept. 18, 1951 2,569,810 Hamel et a1. Oct. 2, 1951 2,574,733 Ehrlich Nov. 13, 1951 2,589,174 Wargo Mar. 11, 1952