US2519302A - Neon sign elements and circuit - Google Patents

Description

Aug. 15, 1950 M. WEINCORD 2,519,302

NEON SIGN ELEMENTS AND CIRCUIT 2 Sheets-Sheet 1 Filed Nov. 1, 1947 WizawzMvzcmM @ffowvwg Aug. 15, 1950 Filed Nov. 1, 1947 M. WEINCORD NEON SIGN ELEMENTS AND CIRCUIT 2 Sheets-Sheet 2 LINE Patented Aug. 15, 1950 UNITED STATES PATENT OFFICE 2,519,302 NEON SIGN ELEMENTS AND CIRCUIT Maurice Weincera, Chicago, 111. Application November 1, 1947, Serial No. 783,474

3 Claims. 1

The present invention relates to illuminated electric signs and more particularly to a sign in which the characters comprise tubular members having some suitable ionizable gas sealed thereinto, said ga becoming luminous when ionized by the passage of electrical current through the same.

In previous signs of this character it has heretoiore been required that the characters be connected in electrical conductivity with the circuit in order that the current pass through the ionizable gas and hence said letters were usually arranged in series with continuous metallic connection, that is, there was required to be a continuous conduit of gas and metal between electrodes. Also the interconnecting portions of the letters where formed of non-intelligence gas bearing conduit, had to be covered with some opaque material, such as black lacquer or the like in order that the sign be intelligible. The peeling of the lacquer with age produced grotesque and undesirable effects. In addition to this, the ends of each conduit had electrodes sealed thereinto, necessitating costly glass-to-metal seals. If the sign were required frequently to be varied as to the intelligence conveyed thereby, each of the characters, in order to be interchangeable had to be provided with electrodes in order to connect same into the circuit, thereby materially increasing the cost of the sign.

A principal object of the invention is to provide an illuminated sign of the class described in which the characters will not be physically connected in the electrical circuit thereby eliminating the disadvantages enumerated above.

A further object of the invention is to provide an illuminated sign in which no ballast or transformer is required to operate the sign, whereby the sign assembly will be rendered economical to produce, light in weight, and small in volume and dimension.

Further objects of the invention are to provide a novel stand for posting sign characters, said stand being simple and compact and being capable of having its length adjusted whereby different numbers of characters may be precisely accommodated thereon.

In addition to the above, the invention contemplates a novel electrical circuit for energizing the characters of the sign to cause them to glow, said circuit being stable and capable of installation in a small space; novel means for connecting a flasher switch into the above circuit in order that said sign be switched off and on for flashing effect; and novel means for .providing power to the above circuit.

An important object of the invention is to provide a novel electrical connector which will enable the characters of the sign to be removable as well as interchangeable on any position of the stand, and which will at the same time provide secure and proper coupling between the electrical circuit of the invention and the said characters.

In carrying out the above objects there is proposed herewith a circuit in which an oscillator is coupled to the characters of the sign parallelly whereby the voltage of the circuit can ionize the gas within the characters thereby causing them to glow. The oscillator is powered by means of a rectified Voltage in the case that the line i alternating current and may be powered by an inverter in the case where the line is direct current.

For a better understandin of how said objects are attained, and of the constructional features of this apparatus, reference will now be had to the accompanying drawings and to the following detailed" specification in which like reference characters designate corresponding parts throughout and in which: i

Fig. 1 is an elevational view of a sign comprising a stand having interchangeable characters associated therewith to convey intelligence and showing the manner in which the invention is utilized.

Fig. 2 is a sectional view taken generally through the stand and showing a manner in which the characters are associated therewith and attached to the cross bars thereof.

Fig. 3 is a sectional view taken approximately along the line 3--3 of Fig. 2 and in the indicated direction.

Fig. 4 is a sectional view taken through one of the uprights of the stand to show a method of attaching the cross bars thereto.

Fig. 5 is a schematic diagram of the electrical circuit of the invention, and

Fig. 6 is a diagram showing the manner of con meeting the circuit of Fig. 5 for use with direct current power.

Referring now more particularly to the accompanying drawings, the reference character l0 designates generally a stand comprising a pair of uprights H and I2 having cross bars l3, l4, l5 and I6 connected therebetween. Each of the cross bars comprises a pair of telescoping tubular metallic members anchored at its related ends to an upright II or 12. In Fig. 2, the cross bar or tube [4 is shown to consist of two members Ma and MD telescoping one within the other in slide trombone fashion. By means of this ar rangement provided for all of the cross bars, l3,

l4, l5 and IS, the stand may be adjusted for length. Thus display legends of many different effects may be formed with the same apparatus.

The precise manner in which the cross bars are anchored within the uprights II and I2 is incidental but one practical way thereof is shown in Fig. 4. The upright ll may be made of some electrically insulating material such as a phenolic cuit presently to be described may readily be housed physically within the upright H or l2 and the electrical connections made by means of short leads. The power connection tothe device is shown at 20.

It will be seen that the cross bars l3 and I4 are 4 power of one of the tubes alone. In actual practice it has been found that two 50L6 tubes are satisfactory, although one triode of the necessary output could be used instead. The heaters 33 of the 501.6 tube are connected in series as shown and to the line through a voltage dropping resistor 34. Reference characters 35, 35, and 31 designate filter condensers for eliminating oscillation through the heaters, connected in conventional manners. The tank circuit elements 25 and 28 are connected between the plates 29 and the grids 3| through the condensers 38 and 39 both connected to the same electrical conductor.

I 1. The cross bars [5 and I6 are likewise both connected to the conductor 18. Any characters which are to be illuminated as a result of flow of current between conductors I! and l8 will therefore bridge one of each of the pairs of cross bars or tubes. The use of such pairs as described makes the standard extremely flexible as to use for and with a greater variety of character sizes. In Fig. 1 for example, three diflferenttypes of characters are shown. It will be noted that. the first character 2| is large enough vertically to bridge all of the cross bars though. it may carry clips 22 attaching only to bars !3 and ;IB.- The central characters exemplified by the letter O and designated 23 encompass the bars l4 and: only and the clips of these characters are therefore attached to said bars. The end character 24 which is here shown as a fancifulv device bridges the bars l3, I4 and I5, and its clips 22 areconnected to cross bars l3 and 15. Obviously the characters should bridge at least one of. each of the pairs of cross bars of different electrical potentials, in order to be illuminated. g

The bars l3, l4, l5 and I6 are antenna parts of an. oscillator circuit which is required in order to produce a voltage sufiicient to ionize the gases within the characters so'tha-t same may glow. In Fig. 5 there is shown a schematic diagram of-one such circuit, which is asimple stable oscillator;

The tank circuit which controls the frequency of. the oscillator comprises an-inductance 2 5 in parallel with a capacitanceZS. The constants of these elements are chosen such that the frequency of oscillation is approximately 1700 vkilocycles. The exact frequency is not vital but is indicated by certain limits determined on the one hand by the dimensions of the stand l0 and on the other hand by the size of the frequency-controlling elements of the circuit. For example it may notice practical for the frequency to be so high that the wavelength coincides with the length ofthe stand because of the undesirability of standing waves along the cross bars which can under suchcircumstances result. i Y 7 Losses resulting from inefficient transmission can be substantial and the expense of operating an inefiicient circuit would be wasteful. Low frequency elements are usually largeandrunnecessarily costly. A suitable frequency should for industrial reasons be outside the governmentregulation broadcast range and when properly chosen will cause but insignificant or no interference with radio reception. For practical purposes the range of frequency of the oscillator may be from about 500 kc. up to'about 3,000 kc.

The thermionic tubes 21 and 28 of the circuit are identical and are connected in parallel. with the plates 29, and screen grids 30 are all tied together; the grids 3| are connected together, and the cathodes 32 are interconnected. Thesum effect is that of a single triode having twice the which serve to prevent overloading in case of accidental short circuit across the cross bars l3, l4, l5 and 15. The antenna pair 13 and M are connected with the plates 29, while the antenna pair 15 and I6 are connected with the grids 3|.

. The alternating current supplied by the line is rectified and substantially doubled by the two rectifiers 40 and M and the condensers 42 and 43. The arrangement is used herein for the purposes of raising the voltage of the line for more eflicient response of: the oscillator. The positive side of the rectifier circuit is connected at 44 the center tap of the .tank inductance 25 while the negative side is connected to the cathodes 32 through a bimetal: flasher switch 45. The negative side is grounded through a filter condenser 4'6.

, It hasbeen found that the circuit will operate most efiiciently if a. condenser resistance combination is connected between the grids 3i and cathodes 32 asshown at 4'! and 48. It is probable that when the circuit is broken and the gases in the tubes forming. the characters are de-ionized, between the cycles; the condenser- resistor combination 47 and 48 stores sufficient voltage to substantially aid the commencement of an ensuing cycle by producing a surge sumcient to cause flow of electrons. The constants of the combination. can be determined by those skilled in the art, and depend upon the frequency of the oscillator. A resistance of 20,000 ohms in parallel with a capacitance of .00025 microfarad has given excellent results.

It should be noted that there is provided a novel way of causing the sign to flash. Instead of conmeeting a flashing device in the line, the flasher device 45'hasbeen connected in the cathode circuit.: It operates by heating up during passage of current and causes the bimetal to move to a position disconnecting the circuit and halting passageof current therethrough. Cooling of the bimetal re-establishes the circuit and re-starts the cycle. The use of the device 45 in the cathode circuit eliminates direct making and breaking of the line current with its inherent disadvantages of arcing and fouling. A more flexible control over the circuit is obtained by the use of theflasher' in the cathode circuit whence it has been-found to merely dim the illumination of the characters instead of totally extinguishing them.

The pairs of cross bars l3-l4' and |5| 6 serve as conductors and the characters are connected in parallel therebetween. Since the frequency is in the radio range, simple capacitive and inductive coupling is sufficient for eflicient and effective connection. The characters therefore are not physically connected into the oscillating circuit, but instead there are provided straddle clips 22, hereinabove referred towhich serve dual purposes as will now be discussed.

These clips springably hold the characters to the cross bars and serve as electrical capacitance elements to couple the characters into the circuit. Each-clip consists of two substantially identical members 49 and 50 having a generally U-shaped formation and made from resilient conducting material. These members are positioned back to back and are swiveled to one another by means of a single rivet 5i in order that each may be adjusted to any desired arrangement for the requirements of the various shaped letters and/or antenna bar. The ends of the members 49 and 50 are flared outwardly as shown at 52 in order to facilitate the ready attachment of the clips 22 to either the cross bars or the characters.

It has been found that the use of clips of the nature herein described is advantageous since the encirclement of at least a portion of each of the characters thereby provides the coupling necessary to permit the transmission of the radio frequency energy required to ionize the gases in the characters. The exact nature of the coupling is believed to be capacitive or a combination thereof with inductance. pling provided by the arrangement described also serves to eliminate or minimize radiation from the sign, as well as to provide a maximum of efficiency therefor.

It is intended that the sizes of signs manufactured in accordance with the invention be substantially small compared to the wave lengths of the frequencies involved.

An examination of the circuit shown in Fig. 5 reveals that no heavy needed for the invention. No ballast, transformers, or other inductances are used, the result being that the circuit can be compactly built and housed within a very small space and requiring but very light materials. Also the problems of hum, interference and heat dissipation are practically eliminated.

With respect to the use of coupled characters, no unsightly wires are needed and the characters are interchangeable and not interconnected. This results in a highly practical display device, especially where there are frequent changes to be made.

Although described tion with alternating current tion is adaptable for use with direct current power by the addition to the circuit of an inverter such as for example, a vibrator. In such case, the inverter is inserted in the line ahead of the circuit as shown in the diagram of Fig. 6 where the line is a direct current source and is connected to the inverter 53. The leads 5d and 55 correspond to those of Fig. 5 while 50 represents the entire functional circuit shown in Fig. 5 beyond the leads 54 and 55 with the exception of the circuit leading to the heaters 33 from the line. The leads of this circuit are designated 51 and 58. It is not required that the heaters use alternating current and hence there is no necessity of placing the additional load on the inverter 53. The leads 51 and 53 in the case of Fig. 6 are therefore directly connected with the line. All of the filter condensers 35, 36 and 31 may not be necessary in this case, depending upon the D. C. ripple of the line,

Certain theoretical explanations have been advanced above in order to clarify the description but it is not intended to be limited thereby. While the present invention has been explained and described with reference to but few specific illustrations, it is to be understood, nevertheless, that numerous variations and modifications may be invoked without departing from the essential spirit and scope thereof. of a number of oscillator herein for use in conneccircuits may be used The close couelectrical equipment is power the inven- For example any one instead of the type shown and described herein. Accordingly, it is not intended to be limited by the specific details of the accompanying illustrations, nor by the particular wording in the foregoing detailed description, except as indicated in the hereunto appended claims.

The invention claimed is:

1. In an electric display device, the combination including, a high frequency signal oscillator system having output terminals connected to longitudinally disposed antenna elements, telescopic tubular sections comprisin extensible components of said antenna elements arranged in a parallel alignment within common plane, individual gas filled character elements contain ing ionizable gases which glow during high frequency conductivity, and means for coupling said character elements to opposite antenna terminals comprising embrasure clips having electrical communication with said tubular sections and having circumference defining curvature to envelope between 50 and 75 per cent of the tubular circumference of said character elements.

2. In a display device, a system of supporting conductors comprising extensive tubular elements parallelly arranged in planar alignment, character elements shaped of tubular transparent material and filled with ionizable gases, and means for mounting said characters on said planar alignment of tubular elements comprising electrically conductive embrasure clips for engaging said conductors circumferentially and additional embrasure clips pivotally secured to said electrically conductive embrasure clips for engaging said character elements whereby various angles of the tubular portions of said character elements may be circumferentially embraced for securement to said tubular elements.

3. A supporting standard for ionizable display material comprising a pair of vertically disposed uprights, a plurality of pairs of horizontally disposed electrically conductive tubes in each of said uprights telescoping into correspondingly spaced horizontal tubes in the other of said uprights, a high frequency generating circuit having one antenna terminal connected with predetermined ones of each pair of said horizontally disposed tubes of both of said uprights and the other of said terminals connected to the other ones of each pair of horizontally disposed tubes whereby signal radiation through space between said tubes is effected during various conditions of telescopic elongation between said tubes in accordance with predetermined display requirements.

MAURICE WEINCORD.

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

UNITED STATES PATENTS Number Name Date 699,208 Moore May 6, 1902 1,308,695 Bushovski July 1, 1919 1,993,943 Nunez Mar. 12, 1935 2,092,508 I-Iammar Sept. '7, 1937 2,184,530 Penny Dec. 26, 1939 2,291,467 Goldberg July 28, 1942 FOREIGN PATENTS Number Country Date 435,931 Great Britain Sept. 23, 1935 449,977 Great Britain July 8, 1936

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