USRE18678E

USRE18678E - Slash lamp

Info

Publication number: USRE18678E
Authority: US
Publication date: 1932-12-06

Description

`vJ. CSTERMEIER Dec, 6, 1932. FLASH LAMP i Reg. 18,678

v originan Fuga April 5. `1929 -ZYVM/ ning speed in a bulb filled with pure oxygen Reissuecl Dec. 6, 1,932

UNITED STATES PATENT FFLCE JOHANNES OSTERMEIER, 0F ALTHEGNENBERG, (zTrEIEtlltlAN'Y,` ASSIGVNOR, BY MESNE ASSIGNMENTS, TQ GENERAL ELECTRIC COMPANY, A CORPORATIONOF NEW YORK FLASH LAMP d Original No. 1,776,637, dated September 23, 1930, Serial No. 352,705, led April 5, 1929, and in Germany February 28, 1929. Application for reissue filed August 9, 1932. Serial No. 628,758.

The invention relatesvto Hash lamps, more particularly those intended for photographic purposes. Flash lamps are already known in which an oxidizable metal in the form of wire or ribbon or a flash mixture is lodged in a as-tight transparent bulb which contains a lling of oxygen, of an oxygen-gas mixture, or of a gas that gives oft' oxygen, such as-an oxide of nitrogen as N20, at a pressure less than atmospheric. From these known fiash lamps the lamp according to the invention differs bythe fact that foils of oxidizable substances, more particularly of metals and metal allows are used as a light producer which foils are so arranged in the bulb as to be in the range of an igniter.

Tests have proved that. foils burn away at an extremely high speed, when the necessary oxygen or combination is present in suficient purity and under suitable pressure. This rapid combustion takes place if the filling of the bulb contains the saine percentage of oxygen as contained in atmospheric air. Now, the remarkable diierence exists in the combustion, e'. g. of aluminum foils in the free air taking place very slowly, so to say crawlingly,while it takes place with lightunder a pressure of 150 mm. Hg. As measurements have shown, in this case the average duration of the combustion amount to 1/40 second. The speed of the combustion can be increased by increasing the vpressure of the oxygen. In this case the phenomenon is to be observed that the lightning eiiect 'of the metal foil when burned in atmospheric air amounts only to one hundredth of that obtained by burning the foil in an equal quantity of pure oxygen under a pressure of 150 mm. Hg. within the bulb, 'the pressure ofV the gas in the bulb Athen being reduced in the proportion of the percentage of oxygen in the atmospheric air, that is iu the proportion of about 21 79. l

Substances well suited to be used as foils are metals7 metal alloys, and rare earths, such as aluminum, copper, iron, nickel, phosphorbronze, cerium, zirconium, and also organic substances. The combustion of the foil may be initiated by any suitable ignitingdevice.

In order that the invention can be more easily understood, a preferred embodiment of an electrically ignited flash lamp accord-l ing to the invention is illustrated by way of example in the drawing, which shows a side view, partly in section, of the lamp.

The lamp has the shape of a normal electric incandescent lamp. The bulb l possesses the usual glass neck 2 with a sealed-in small tube 3 serving to'draw off/the air or to fill the bulb with the gas. The conducting wires 4a, 4b are likewise sealed in the neck 2 and extend approximately upto the midst of the bulb. Near their upper ends the Wires 4, 4b are held in place by means of a glass piece or rod 5 and are interconnected at their ends by filling are the greater, the smaller the thick ness of the foils. The thickness ofthe metal foils amounts to about 0.0005 mm. The pressure of the oxygen in the bulb is between 12o-180 mm1 Hg.

The described lamp need not be equipped with any means :for securing it against explosion when the bulb happens to become leaky. This resides in the fact that in case of leakiness of the bulb the combustion of the metal foil takes place very slowly so that a dangerous increase of pressureis avoided due to the heat of combustion being given off to the air surrounding the lamp. The only drawback of the lamp becoming leaky is that the lamp cannot be used as a. flash lamp.

As can be seen from the foregoing, the igniting Wire 6 and the composition 7, if any, burn away when electric current is supplied. The ame of the combustion ignites the surrounding foil lilling-8. Of course, the lling must be within the range of the described igniter. The costs of production of the lamp are very low as the above-mentioned safety means may be dispensed with and the possibility is present to use very cheap foil material.

' with a gaseous oxygenic substance; an ignittight transparent of a normal pocket lamp battery is sufficient` to cause ignition. This therefore affords the advantage of the use of the lamp without depending upon an electric supply system.

When used for photoglraphic purposes, the bulb may be fitted inside or outside with a layer of a material, such as a yellow Hlter or tartrazin that absorbs a portion of the rays ofthe spectrum of the light emitted, or the bulb itself may be made of a material, such as yellow glass, having such an absorbing effect. f

What I claim and desire to secure by Letters Patent is 1. A Hash lamp particularly for photographic purposes, comprising a closed gastight transparent bulb containing an oxygen g as; and a foil in the bulb adapted to emit ight gen and disposed within effective range of an upon combustion thereof with the oxyignition device.

2. A Hash lamp particularly for photographic purposes, comprising a closed gasbulb containing an oxygen as mixture; a foil inthe bulb adapted to emit light upon combustion thereof with the oxygen and disposed within effective range of an ignition device; and a screen associated with the bulb for absorbinga portion of I the rays of the spectrum.

3. A Hash lamp particularly for photographic purposes, comprising a closed gastighttransparent bulb containing a gas capable of yielding oxygen; and a foil in the bulb adapted to emit'light upon combustion thereof with the oxygen effective range of an ignition device, said bulb being adapted toabsorb a portion of the rays of the spectrum.

4. A Hash lamp particularly for photographic purposes, comprising a closed gastight bulb having a gastherein; an igniting device in said4 bulb; and

a foil in the bulb adapted to emit light upon combustion there- -of with the gas and disposed Within'eiective range of the ignition device.

-5. A flash lamp, comprising a bulb filled V with a gaseous oxygenic substance at a pressure less than atmospheric; an igniting device in said bulb; foil of oxidizable substance in said bulb in the ignition range of said device; and a layer on said bulb of a substance adapted to absorba portion of the rays of the spectrum.

6. A Hash lamp, comprising a bulb filled ing device in said bulb; foil of oxidizable substance in said b ulb in the ignition range of said device, said bulb ignition device,

and disposed Within being of a material adapted to absorb a portion of the rays of the spectrum.

7. A flash lamp, comprising a bulb filled with a gaseous oxygenic substance; an electric vigniting device arranged in said bulb and comprising two conductors extending tive range of an ignition device.

9. A flash lamp particularly for photoraphic purposes, comprising a closed gas tight bulb having a gas therein; au ignition Ydevice in said bulb; and a loose filling 'of foil in the bulb adapted to emit light upon conibustionA thereof with `the gas and disposed Within effective range of tlie ignition device.

10. A Hash lamp particularly for photographic purposes, comprising ay closed gas tight transparent bulb containing a gas at a pressure substantially below atmospheric and a loose filling of foil in the bulb adapted to emit light upon combustion thereof with said gas and disposed Within effective range of an the thinness of the foil being such that the foil will burn with lightning speed.

In witness whereof, I have hereunto set my hand.

JOHANNES OSTERMEIER.