US2066833A - Glow lamp - Google Patents

Description

Jan. 5, 1937. GERTLER 2,066,833

GLOW LAMP Filed Nov. 25, 1935 'fyi J27? INVENTOR. xiv/nun E. GER r1. 5/

ATTORNEY.

Patented Jan. 5, 1937 GLOW LAMP Samuel E. Gertler, New York, N. Y., alsignor of one-half to Harry I. Stein, New York, N. Y.

Application November 25, 1935, Serial No. 51,376

11 Claims.

My invention relates to glow-lamps, more particularly to that type of lamp wherein the light emitting element, which is a closed conductor, is supported in a transparent receiver containing an inert gas such as neon gas or argon gas,

or from which all air and other gaseous substances have been exhausted, said glow-lamp being subject to the inductive influence of the field produced by high frequency electric currents of exceedingly high potential located exteriorly of the transparent bulb or container.

One of the objects of my invention is to provide a new and improved glow element of such construction that all parts of the light emitting surface will be equally luminous whereby the en-- tire cross-sectional area of the beam of light remitted from the said light emitting surface will have a uniform degree of luminosity.

Another object of my invention is to so form the glow element that the heat produced within the same by induction by the high frequency current of high potential in the exterior coil will .result in an equal distribution of the heat throughout the body of the glow member, causin: the latter to emit from its light emitting surface, a beamof light, all parts of which have equal illuminating values.

Another object of the invention is to provide a glow element of the above type in which the so light rays emitted from the light emitting surface are disposed in parallel relation or which may be caused to converge or diverge as they are cast from said light emitting surface.

A further object of my invention is to provide 36 a glow element in the form of a disc and composed of a metal such as tungsten, the thickness of which is so varied that the tendency of the high frequency current of high potential to heat the disc with a greater degree of intensity at its 40 periphery than it does the areas located within the periphery and extending to the axis of the disc is eliminated.

Other objects and aims of the invention, more or less specific than those referred to above, will 45 be in part obvious and in part pointed out in the course of the following description of the elements, combinations, arrangements of parts and applications of principles, constituting the invention; and the scope of protection contemplated will be indicated in the appended claims.

In the accompanying drawing wherein I have illustrated preferred forms of embodiments of my invention,

Figure 1 is a vertical sectional view taken through a bulb or receiver showing my improved glow element mounted therein,

Figure 2 is a side elevational view of a glow element constructed in accordance with one embodiment of my invention, 5

Figure 3is a similar view of another embodiment of my invention,

Figure 4 is a similar view of still another embodiment of my invention, and

Figure 5 is a similar view showing a glow member of a slightly different conformation having a fiat light emitting face and an opposite face having a conformation slightly different from that of the preceding figures.

Referring now to the-drawing wherein similar reference characters refer to similar parts throughout the several views thereof, the reference numeral I denotes a sealed bulb or casing which, in the present instance, is preferably formed of a transparent material such as quartz, the latter having an exceedingly high melting point. It will be understood that I preferably fill this bulb or receiver with an inert gas preferably neon gas or argon gas, or, if I elect, I may exhaust all of the air and other gaseswhose presence have deleterious effect on the glow element within the bulb or receiver.

I prefer to erect a post 2 on the bottom wall of the bulb or receiver and from the upper end of this post, extending in diverging relation is a plurality of wires 3, preferably formed of a high melting point metallic substance such as tungsten. The upper ends of the wires 3 are provided with integrally formed hooks 4 of such construction that the glow element 5 may be supported thereon so that the latter will lie in a plane at right angles to the plane of the coil I which, in the, present instance,- is positioned exteriorly of the bulb or container I. It is understood that the glow element 5 has a circular periphery and is symmetrically disposed with respect to the coil 6 and lies in a place cutting the middle portion of the said coil. The coil 6, as is usual in this type of lamp, is energized from a suitable source of energy by a current of high frequency and exceedingly high potential so that the glow member will be heated by inductance. The glow member 5 in the present instance is preferably formed of a metal having a high melting point, preferably tungsten.

At this point it may be noted'that in lamps of this character as hitherto constructed, all parts of the beam of light emitting from the light emitting surface of the glow member have been of unequal illuminating value, due to the dimculty 5g of heating to equal degrees all parts of the mass of the glow member. It has been found that the metal adjacent the outer edge of a disc shaped glow member of this character is hotter than the inner parts thereof, and that the metal ls progressively cooler in an inward direction toward the axis of the disc. This is due to at least two factors, first, that the inductance has a stronger effect on the outer edge of the metal than it has on the metal within the periphery, and to the fact that the heat conductivity of the metallic member is such that an even distribution of the heat does not take place with such rapidity as will maintain all parts of the glow member equally heated. This defect or objection has resulted in the emission of a beam of light from the glow member, parts of which have varying illuminating values.

I overcome this objection by increasing the thickness of the metal from the periphery of the disc to its central axis so that the magnetic induction combined with the normal heat conductivity of the disc shaped glow member will result in a body which has all of its parts heated equally so that the incandescence of the glow member will be equal throughout its entire body, thereby insuring a light beam, every part of which is equal to the other parts in its degree of luminosity.

One way of accomplishing this result is shown in Figure 2 of the drawing in which a disc formed tungsten has the plane light emitting surface I and the convex surface 8, the convexity of which is plotted with a curve that will accomplish the results above enumerated. In following this curve of convexity, the conductivity of the metal, comprising the disc has to be considered, so that the absorbed heat energy will be evenly distributed throughout the metallic mass of the glow member. The curve of convexity of the surface 8 in the glow member illustrated in Figure 2 of the drawing is such that the glow member will be uniformly heated and the rays of light forming the beam emitted from the surface I of the glow member will lie in parallel relations, the latter object being attained by making the entire light emitting surface 1 lie in a common plane.

In Figure 3 of the drawing I have provided a glow element wherein both of the surfaces 9 and Ill of the tungsten disc are of convex conformation. A glow member so constructed will emit rays which will diverge from the light emitting surface.

In Figure 4 I have provided a glow member of concave convex form whereby the light rays emitting from the light emitting surface II will be in divergent relation. It is intended, however, in all of.;these forms of embodiments of my glow member that all of the parts of the metal will be such that a beam of light will be cast, all parts of which are of equal value.

In Figure 5 of the drawing I'have illustrated a slightly different form of glow member, the light emitting face being flat as shown in Figure 1 and the opposite face having angular circular facets. In this embodiment of this invention, however, it is intended that all of the mass of the metal composing the glow member will be heated by the inductive field considering the conductivity of the metal.

It is, of course, a known physical law that the effective influence of the magnetic field induced by the symmetrically disposed coil, energized by a high frequency, high potential current, as

described, diminishes at a predetermined ratio in an axial direction toward the center of the glow member. My aim is to correct this defect in glow members as hitherto constructed by increasing the body of the metal mass from themriphery of the disc towards its center to compensate for this diminution of induced heat energy, and at the same time taking into consideration the conductivity of the metal mass. The curve defining the convexity of at least one of the surfaces of the glow member will, of course, have to be plotted with due consideration to these two factors.

It will be understood. of course, that in a lamp of this type objective lenses (not shown) are employed so that such concentration or dispersion of the light rays upon a screen, as are desired, may be provided.

It will accordingly be seen that I have provided a lamp having a glow member so constructed as to accomplish, among others, all the ends and objects of the invention in a most facile manner, the construction being such that all parts of the glow member are continuously heated at equal temperatures and a steady beam of light, all parts of which have equal light values, will be emitted from the light emitting surface thereof.

As many changes could be made in this construction without departing from the scope of the following claims, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative only and not in a limiting sense.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

1. In a device of the class described, in combination, a glow member for an electric lamp comprising a circular disc shaped member, formed of tungsten, said glow member being relatively thin at its peripheral edge portion and becoming relatively thicker along its radii, the material of said glow member being so distributed that heat produced by electric currents induced within itself by a current of high frequency will effect a uniform heating of all parts of the material of said disc shaped member, and a coil coaxially disposed with respect to said disc shaped member for inducing a current of high frequency in said disc shaped member.

2. In a glow-lamp, in combination, a circular glow member, the material of which is relatively thin at its peripheral edge and which becomes thicker as it approaches its central axis, a transparent envelope, an induction coil surroimding said envelope, and means for supporting said glow member within said envelope coaxially disposed with respect to said coil.

3. In combination, a circular glow member for an electric glow-lamp the material of which is relatively thin at its peripheral edge and which becomes thicker as it approaches its central axis formed of a high fusing point metal being so formed that all parts of its material are evenly heated by induction produced by a high frequency current, and a coil disposed coaxially with respect to said glow member for conducting said high frequency current about said glow member.

4. In combination, a circular glow member for 7 an electric glow-lamp, formed of a high fusing point metal and having a list light emitting surface, said glow member being relatively thin at its peripheral edge and which becomes thicker as it approaches its central axis so that the entire light emitting face is uniformly luminous under the influence of heat produced by induction by a high frequency current, and a coil disposed coaxially with respect to said glow member.

5. In combination, a glow member for an electric glow-lamp, comprising a disc shaped member, relatively thin at its peripheral edge portions and becoming relatively thicker along its radii and having a light emitting surface, the material of said glow member being so distributed that induced current produced by a current of high frequency in a coil coaxially disposed with respect to the glow member is adapted to inductively heat the latter, whereby the entire area of the light emitting surface will be uniformly heated, and a coil so disposed with respect to said glow member.

6. In combination, a glow member for an electric glow-lamp, comprising a disc like member formed of a high fusing point metal, said disc like member being relatively thin at its periphery, said glow member having a fiat light emitting face and a convex face located in opposition thereto, the material of said glow member being so distributed that heat produced by a current of high frequency will induce currents within said disc like member, and a coil coaxially disposed with respect to the glow member energized by said current of high frequency to heat the latter whereby the light emitting surface will emit light of a uniform intensity throughout its entire area.

7. In combination, a glow member for an electric glow-lamp, comprising a disc like member, one surface of said glow member being fiat and the opposite face convex, the arc of the curve defining said convex surface being so plotted that, considering the conductivity of the metal, the entire mass of the metal composing said glow member will be heated uniformly by induction by currents induced within itself by a current of high frequency passing through a coil disposed coaxially with respect to the periphery of said glow member, and a coil so disposed with respect to the periphery of said glow member.

8. In combination, a solitary glow member for an electric glow-lamp, comprising a circular member formed of a high melting point material, at least one surface of said glow member being convex, the arc of the curve defining said convex surface being so plotted that, allowing for the conductivity of the metal, the entire mass of the metal comprising said glow metal will be heated uniformly by high frequency current passing through a coil disposed coaxially with respect to the periphery of said glow member, whereby the entire area of the light emitting face of the glow member will emit a beam of light of uniform intensity, and a coil so disposed with respect to the peripheryof said glow member.

9. In combination, a glow member for an electric glow-lamp, comprising a circular disc like member formed of a high melting point material, one or more of the faces of said glow member being convex, the convexity of which is defined by a curve so plotted that, considering the conductivity of the metal composing the glow member, all parts thereof will be-heated to a uniform degree by currents induced within itself by a high frequency current passing through a coil disposed coaxially with respect to the periphery of the glow member, and a coil so disposed with respect to the periphery of said glow member for inducing said current of high frequency in said glow member.

10. The combination in a glow-lamp, of a closed envelope filled with an inert gas, said envelope being composed of a transparent substance having a high melting point, a coil disposed exteriorly of said envelope energized by a high frequency current, a glow member suitably supported within said envelope so as to be coaxially disposed with respect to said coil, said glow member being composed of metal having a high fusing point, said glow member having a circular periphery, the material of said glow member increasing in thickness from its periphery towards its center along a curve of predetermined plottage whereby, making provision for the electrical conductivity of the metal, the entire mass of the glow member -will be heated uniformly by induction, and the luminosity of its light emitting surface will have a uniform value throughout its entire area.

11. A glow lamp comprising an envelope, a solitary disc like glow member suitably supported within said envelope, an induction coil surrounding said envelope, said glow member having a circular peripheral edge and being thicker at its center than at its peripheral edge.

SAMUEIJ E. GERTLER.

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