US2117544A - Lighting by sustained luminescence - Google Patents

Description

May 17, 1938.. R. A. COUSTAL LIGHTING BY SUSTAINED LUMINESCENCE 2 Sheets- Sheet 1 Filed Oct. 29, 1955 Patented May 17, 1938 UNITED STATES LIGHTING BY SUSTAINED LUMINESCENGE Rene Andre Coustal, Saint-Mam, France, assignor to Socit Anonyme Stella-Luis, Paris,

France Application October 29, 1935, Serial No. 47,326

. In France October 29, 1934 1' Claim.

The present invention relates to the technics of lighting by means of materials the luminescence of which is electrically sustained, for instance by means of high frequency high voltage currents.

In this art, use is made of lamps constituted by glass bulbs containinga gas rarefied ,to cathodic vacuum and the inner face of which receives a layer of luminescent material. 10 By maintaining in the bulb a high frequency high voltage current, the luminescence of the layer of material is sustained.

The present invention concerns improvements in the technics of this lighting. 13 These improvements relate both to the manufacture of the lamps and to their supply or energization and their applications.

They are mainly characterized by the following points, applicable separately or in combination:

(a) The application of phosphorescent or fluorescent materials (particularly: zinc sulphide,

calcium tungstate, uranyl salts, and the like employed separately or. in mixtures) on the inner face of the bulb constituting the lamp, and in totality or in zones, is effected by moistening this face and by spraying on the moistened zone the luminescent material in powder form.

(1)) The liquid for moistening the inner face of the bulb is distilled water.

:30 (c) The liquid for moistening the inner face of the bulb is a solution of zinc chloride (ZnClz) ((1) After drying the luminescent powder, the bulb is connected to a source of vacuum and exhausted as perfectly as possible whilst the powder 3 is freed from gases, either by moderate heating, or by intense energization at a high frequency, or again by both these means applied simultaneously.

(e) After the bulb has been exhausted, a rare 40 gas, such as: helium, neon, argon, krypton or kenon, is introduced therein, whilst a high frequency high voltage current is sustained in order to control, according to the brilliancy of the lamp, the pressure of the rare gas introduced, this 5 pressure being usually much lower than one millimeter of mercury. The lamp is subsequently sealed and provided with a conducting socket constituting an electrodesupport.

(f) The lamps are constituted by spherical glass no bulbs with a single electrode or suspension cap.

, (grFor eliminating the localized brush discharges which in course of time cause the neck portion receiving the lamp cap to break, the said lamp cap is provided, at its lower part, with a 55 flange which regularizes the distribution of the electric field, promotes cooling and can eventually serve as lamp-shade.

(h) The metal cap of the lamp is secured to the neck portion of the glass bulb by direct aderence of a metal, such as tungsten, to the exclusion of any cement.

- generator giving a wave length of at least 6000 meters so as not to disturb wireless receptions.-

(I) For indoor lighting the wires supportingand feeding the lamps are in the shape of aerials composed of multiple wires, arranged parallel to 20 each other, or in fan-like fashion or otherwise, and supplied by a high frequency high voltage current-generator, or a rotary current-generator or a station provided with transmitting valves, or of the discharger or are type, the tuning being 0.- eiiected by means of self-induction coils orof condensers.

(m) The lamps are fed by relaxation waves or oscillations and particularly by utilizing dynatrons, singing arcs, so called Crystadyne lay-outs 30 or of the singing crystal type.

(n) When the lamps are hung from a conducting wire supplied as an aerial with high frequency high voltage current, the wire is surrounded by insulating sleeves, preferably made of quartz, isolantite or materials having equivalent properties, which sleeves can constitute mechanical stay members between two adjacent lamps.

The accompanying drawings illustrate, by way of example only, forms of construction of the im- 40 provements according to the present invention.

Figs. 1, 2 and 3'i1lustrate forms of construc-' tion of lamps according to the invention.

Fig. 4 is a diagrammatic view of a road lighting installation. 4 5

Figs. 5 to 10 illustrate wiring diagrams of lamps according to the invention.

The lamps according to the invention are constituted by a bulb made of glass or equivalent material, having a general spherical shape with a n tubular neck portion which allows:

1--The moistening of the inner surface of the bulb, either by means of distilled water, or by means of an aqueous solution of ZnClz, and on the totality or on certain zones only of this surface. 55,

of a fine powder, on to the moistened surfaces where they definitely adhere after drying.

-'-The exhaustion of the bulb and the introduction of a rare gas the pressure of which is determintd by the brilliancy of the luminescent zones when the lamp is placed in a field of high frequency high voltage current.

Concerning the introduction, which is moreover optional, of rare gases into the bulb, it is to be noted that these gases do not intervene for producing a useful light, as is the case for lighting tubes (neon lamps for instance). They simply promote the appearance and sustainment of the phenomena energizing the materials the lumi-.

nescence of which constitutes the only source of light.

As shown in Fig. 1, the bulb being sealed as usual for incandescent lamps, the neck portion 2 'is covered with a metal cap sealed by means of a special cement and which constitutes an electrode and a means for securing the bulb on the supply wire. In the example of Fig. 1, the cap which, moreover, must be devoid of projections capable of producing losses of high frequency current, is provided with a hook 4 for hanging it from the supply wire 5. Other securing means, of the socket type for instance, can obviously be provided. I

The material, the sustained luminescence of which produces the light, is practically of indefinite duration and the wear of the lamps is caused by deterioration of the bulb itself. Thus, in the form of construction shown in Fig. 1, the bulb may break at 2 after a certain time. The

breaking appears to be due to localized brush discharges which cause local heating up of the For remedying thereto, use may be made of the form of construction shown in Fig. 2, in which the cap 3 is provided, at its lower part, with a flange 3 the periphery of which presents a rounded ledge 3 in order to avoid losses of electric energy in the atmosphere. A rounded portion being also provided at 3 and distant from thenarrow portion 2* of the neck, the localized brush discharges are thus eliminated, and, at the same time, it is possible to obtain:

A more regular distribution of the electric field producing and sustaining the luminescence,

A cooling of the cap which thus presents a large surface of contact with the atmosphere.

The upper portion of the flange 3 being blackened and its lower face being polished, a lampshade is thus obtained.

In order to do away with cement ensuring the adherence of the cap 3 to the glass of the neck portion 2 and which, as it never constitutes an insulation, nor a perfect conductor, presents inconveniences, use may be made of the arrangement'shown in Fig. 3, in which the metal of cap 3 is embedded in the glass of the neck portion 2 and of the bulb I. Use can also be made of metals which, as tungsten for instance, adhere to glass and can constitute with the latter a real weld. The inner surface of cap 3 is coated with welded to the latter.

For allowing the neck portion 2 to resist to the effects of temperature, it can be-made of quartz and it can be welded,by known processes, to the glass which constitutes the bulb proper.

If for constructional requirements the cap is to be sealed by means of cement, use can be made of the cement indicated hereinafter which behaves as a dielectric having but small losses in high frequency current.

This cement is constituted by an alloy of sulphur and paraflin and is composed for instance of '75 parts of sulphur and 25 parts of paraflin having a high melting point.

Lamps according to the invention can be used for lighting roads. In the'installation diagrammatically illustrated in Fig. 4, wires 6 are supported, through the medium of insulating chains 7, by posts 8 arranged at intervals along a road and connected, at one end, to the secondary winding 9 of 2. Tesla transformer, the primary winding ill of whichis fed by a high frequency and high voltage alternator ll giving, for instance, a wave length of 10 kilometers, the secondary winding being perfectly tuned. The lamps i2 are secured to wires 6 at any desired distance apart and give, for a reduced consumption of energy, a diffused light very pleasant to the eye.

The electric fields sustaining the luminescence are obtained by damped waves or by sustained waves.

Damped waves have the advantage, concerning the energization of lamps of the above type, of giving rise to high voltage peaks allowing utilization of a relatively reduced mean potential. On the contrary, the fluctuations due to the very nature of the current which is not sinusoidal, give rise to irregularities in the luminescence.

With sustained waves, a regular energization is obtained, but, on the other hand, the absence of voltage peaks necessitates the use of a. higher supply mean potential.

For the purpose of deriving profit from the advantages of each of the modes of supply indi cated,above, without suffering from the inconveniences of the same, the invention concerns the new application, for feeding lamps of the type indicated, of relaxation waves or oscillations. These waves have voltage peaks and a regularity comparable to that of sustained waves, and, in any case, sufiicient for preventing the production of fluctuations perceptible to the eye.

-The invention includes in its scope any generating means suitable for the production of these relaxation waves and particularly the following:

Dynatrons I Singing arcs So-called Crystadyne lay-outs, that is to say singing crystals, such as zincite.

Relating to these latter means, the invention concerns the new application of marcasite the properties of'which, as far as the applicant is aware, have not been used in Crystadyne lay-outs.

Fig. 5 shows a generator for the production of relaxation oscillations, This generator is constituted by a valve having two inner electrodes l4 and [5 connected to the circuit iii of a source of supply of high frequency high voltage current, on which electrodes is shunted a condenser l'l.

Fig. 6 shows a feeder lay-out for feeding lamps IS. The latter are of the suspension hook type described above. They are hung from the wires of the feeders i8 and in electric contact with the same through the hook connected to their electrode. I

In the lay-out of Fig. '7, the lamps l9 are interposed between the feeders I 8, by two hooks 20, or securing means provided with'suitable contacts and connected to the electrodes of the lamps.

In Fig. 8, an aerial wire or feeder [a is s1n'- 5 rounded by sleeves 2| made of quartz, isolantite or like material, which serve as mechanical stay members between two adjacent lamps I! hung from the wire as the lamps I! of Fig. 6. The losses of energy for the wires are thus reduced as explained above.

In Fig. 9, the lamps l9 are externally attached to the insulating sleeves 2| of Fig. 8, either by their suspension hook, or, preferably, by a conducting socket 22, in order to provide condensers allowing the aerial or wire Hi to be better defined.

In Fig. 10 the lay-out illustrated avoids an excessive coefficient of damping of the aerial circuit. At a certain distance from the supply\wire,

. or from the feeder I8, is arranged a wire parallel thereto and from which the lamps l9 are hung. The wire 23 is insulatedat its ends or is connected as an aerial turned on the wave of the aerial constituted by the supply wire. This tuning can be obtained either by the own wave length of the wire II, or by connecting the latter to a closed circuit comprising a capacity and a tuning self-induction coil, or again by earthing it, through a self-induction coil and a. capacity. What I claim as my invention and desire to secure by Letters Patent is: r

In an installation for supplying lamps with electric energy, comprising a transparent bulb for visible radiation and coated with a layer of a solid luminescent or phosphorescent' material.

the said lamps comprising one or two electrodes, a free conducting wire, a source of electric energy connected to the said wire for producing outside the same a variable electric field, sleeves of insulating material surrounding the said wire, conducting sockets surrounding the said sleeves and connected to one of the electrodes, lamps rendered luminescent by the action upon the layer of luminescent or phosphorescent material of the electric field produced outside the said wire.

Rant ANDRE cons-ran

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