US2285125A - Flash lamp - Google Patents

Flash lamp Download PDF

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Publication number
US2285125A
US2285125A US262209A US26220939A US2285125A US 2285125 A US2285125 A US 2285125A US 262209 A US262209 A US 262209A US 26220939 A US26220939 A US 26220939A US 2285125 A US2285125 A US 2285125A
Authority
US
United States
Prior art keywords
flash
primer
lamp
bead
combustible material
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US262209A
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English (en)
Inventor
Pipkin Marvin
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
General Electric Co
Original Assignee
General Electric Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by General Electric Co filed Critical General Electric Co
Priority to US262209A priority Critical patent/US2285125A/en
Priority to US278288A priority patent/US2280598A/en
Priority to FR866015D priority patent/FR866015A/fr
Priority to GB10075/40A priority patent/GB541699A/en
Application granted granted Critical
Publication of US2285125A publication Critical patent/US2285125A/en
Priority to AT163983D priority patent/AT163983B/de
Priority to AT166186D priority patent/AT166186B/de
Priority to CH292829D priority patent/CH292829A/de
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21K—NON-ELECTRIC LIGHT SOURCES USING LUMINESCENCE; LIGHT SOURCES USING ELECTROCHEMILUMINESCENCE; LIGHT SOURCES USING CHARGES OF COMBUSTIBLE MATERIAL; LIGHT SOURCES USING SEMICONDUCTOR DEVICES AS LIGHT-GENERATING ELEMENTS; LIGHT SOURCES NOT OTHERWISE PROVIDED FOR
    • F21K5/00—Light sources using charges of combustible material, e.g. illuminating flash devices
    • F21K5/02—Light sources using charges of combustible material, e.g. illuminating flash devices ignited in a non-disrupting container, e.g. photo-flash bulb
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S149/00—Explosive and thermic compositions or charges
    • Y10S149/11—Particle size of a component
    • Y10S149/114—Inorganic fuel

Definitions

  • My invention relates to flash lamps and more particularly to that type of flash lamp used for photographic purposes.
  • Such flash lamps usually comprise a sealed transparent bulb in which is enclosed a readily combustible material such as metal foil and/or wire, together with suitable ignition means therefor, and a substance, usually a gas filling, which, upon ignition of the lamp enters into a reaction with the combustible material with the resulting emission of actinic light.
  • a substance usually a gas filling, which, upon ignition of the lamp enters into a reaction with the combustible material with the resulting emission of actinic light.
  • my invention relates to flash lamps employing substantially pure aluminum, in the form of a wire or ribbon, as the combustible material together-with efiective ignition means therefor.
  • the combustible materials which have been found most suitable for use in flash lamps consist of either a thin metallic foil or wire which, when ignited in an oxygen or oxygen-containing atmosphere, burns very rapidly with the emission of a substantial amount of actinic light.
  • foil flash lamps due to the tremendous amount of actinic light developed upon their ignition and to the relatively great speed of the flash, are particularly advantageous and useful for certain types of photographic work, commonly referred to as the open flash, wire flash lamps, due to their longer flash period, are preferred for synchronized flash work in which the flash of the lamp occurs simultaneously with the opening or tripping of the camera shutter.
  • One object of my invention is to provide a flash lamp which will produce, upon ignition, a flash of light of relatively high intensity and of prolonged duration, and having its peak at about 0.020 of a second following energization of the lamp ignition means.
  • Another object of my invention is to provide a flash lamp, employing a drawn wire or ribbon of pure aluminum as the sole combustible material, which will produce a flash of light of suincient speed and intensity for flashlight photographic purposes.
  • Still another object of my invention is to provide a flash lamp, employing as the sole combustible material drawn pure aluminum of a fineness corresponding to a diameter of approximately one mil, with a primer or ignition bead which will cause the fine aluminum to burn quickly so as to produce a flash of light of relatively high intensity having its peak at about 0.020 of a second following energization of the filament embedded in said primer bead.
  • a further object of my invention is to provide uniformly performing flash lamps in which the flashes of light produced thereby are uniform in character and occur at approximately the same interval of time following energization of the lamp ignition means.
  • a still further object of my invention is to provide a primer bead for flash lamps which will ignite uniformly and with great speed, and will be expanded or distributed quickly throughout the lamp bulb :upon energization of the filament embedded in such bead.
  • Fig. 1 is an elevation of a flash lamp comprising my invention
  • Fig. 2 is a chart showing the light curve produced by the flash lamp shown in Fig. 1, the abscissa representing time in milliseconds and the ordinate representing intensity of light in millions of lumens.
  • the flash lamp there shown comprises a vitreous transparent envelope or bulb l containing a loose filling of combustible material ll consisting essentially of substantially pure drawn aluminum wire or ribbon having a fineness corresponding to a diameter of approximately one mil or very close thereto.
  • This fine pure aluminum wire may be produced either by conventional mill die-drawing methods or by the special drawing process disclosed in my United States Patent No. 2,215,477 previously referred to, in which the aluminum is drawn to the required size inside a copper jacket and the copper then dissolved off, leaving the bare aluminum wire.
  • the envelope or bulb II) also contains a filling of oxygen or oxygen-containing gas at a suitable pressure for supporting the combustion of the combustible material II.
  • the pressure of this gaseous filling will vary depending upon the type of filling, the size of the bulb, and the quantity and type of combustible material therein. For bulb sizes commonly in use at present, and with oxygen being used as the combustion-supporting gas and pure aluminum as the combustible material, the pressure of the gaseous filling will vary up to 500 mm. of mercury.
  • a small filament l2 mounted within the bulb Ill within effective ignition range of the combustible material I I therein, is a small filament l2 the ends of which are connected to leading-in wires l3, l3 which extend through a stem I4 to a base l5.
  • An insulating disc l6, preferably of asbestos, is mounted on the stem I4 to shield the base end of the lamp from the heat of combustion.
  • the filament I2 is embedded in a bead I! of fulminating substance similar to that disclosed in my co-pending United States application Serial No. 203,890, filed April 23, 1938, to thereby form the ignition means for the lamp.
  • the fulminating substance is applied to the filament l2 in the form of a paste consisting of an extremely sensitive metal powder or powders and a suitable oxidizing agent mixed with a suitable binder.
  • the sensitive metal powder consists of a mixture of the grade M and grade No. 3 zirconium metal powders manufactured and sold commercially by the Foote Mineral Company of Philadelphia, Pennsylvania. The grade No.
  • 3 zirconium metal powder has a fineness of approximately 325 mesh or finer and has a relatively high ignition temperature, while the grade M zirconium metal powder is considerably finer than the grade No. 3 zirconium powder and has a relatively low ignition temperature.
  • Chemically pure (C. P.) crystal potassium perchlorate powder having a fineness of approximately 325 mesh or finer, is employed as the oxidizing agent.
  • a slowdrying and preferably non-gummy binder, such as glue is employed.
  • the preferred composition of the above primer bead material is approximately as follows:
  • the primer bead mixture is prepared as follows: 4 grams of crystal potassium perchlorate (C. P.) is first ground to a fineness of 325 mesh or finer and then added to 5 cc. of the one per cent glue water, the powdered potassium perchlorate being stirred in thoroughly. Next, 2.6 grams of zirconium No. 3 metal powder is added and stirred in thoroughly, after which 2.6 grams of zirconium M metal powder is added and stirred in thoroughly. To obtain a homogeneous mixture and to thin out the same, an additional amount of water is added, the additional water effecting a more complete solution of the potassium perchlorate powder. The excess water is then evaporated by blowing the mixture with an air jet until the correct consistency is obtained.
  • C. P. crystal potassium perchlorate
  • the filament I2, together with its associated leading-in wires I3, I3, is then dipped into the above mixture to form a bead covering the filament and adjacent portions of the leadingin wires.
  • Two applications by dipping have been found to produce the right size primer bead.
  • an insulating or protective coating of suitable material is applied thereover to thereby add mechanical strength to the bead and also to protect the same from premature ignition during the testing of the completed flash lamp.
  • the said protective coating may consist of either cellulose acetate or a 4 per cent solution of nitrocellulose.
  • a suitable amount of potassium perchlorate or other similar oxidizing agent may be added to the coating to thereby facilitate the burning of the same.
  • a 4 per cent solution of cellulose acetate consisting of approximately 8 grams of cellulose acetate, cc. of acetone and 100 cc. of ethyl lactate, may be employed as the binder material instead of glue.
  • the preferred composition for the primer bead material is approximately as follows:
  • the zirconium M metal powder may be replaced by tungsten metal powder having a fineness of approximately 325 mesh or finer.
  • the preferred composition for the primer bead material is then approximately as follows:
  • the filament is thus entirely embedded in, and is completly covered over its entire surface area with the hardened fuiminating substance ll. Every bead made from the above-described mixture will therefore be of uniform internal physical structure, so that the firing action or speed of ignition of each bead tends to be uniform. Flash lamps provided with such uniformly acting primer beads are thus rendered more uniform in flash performance, thereby facilitating the synchronization of a camera shutter with the light peak of such flash lamps.
  • the potassium perchlorate powder employed in the primer mixtm'e according to the invention provides an extremely abundant supply of oxygen for supporting the combustion of the sensitive metal powders.
  • the primer bead ignites very.quickly and with great rapidity as compared to conventional primer mixtures heretofore used.
  • the burning particles of primer material are projected with tremendous speed from the filament l2 and are quickly distributed through the bulb, thus causing the fine aluminum wire to ignite with great speed,much faster than takes place when conventional primer mixtures are employed. Consequently, the use of such a quick-igniting primer bead in accordance with the present invention makes it possible to employ drawn pure aluminum wire as the sole combustible material in flash lamps, for such a primer head will effectively ignite the aluminum wire in the lamp.
  • Drawn pure aluminum wire having a size corresponding to a diameter of 1.0 or 1.1 mils, or slightly larger, can therefore be successfully employed in flash lamps for the production, upon ignition by a primer bead according to the invention, of a flash of light of sufflcient intensity and output for flashlight photographic purposes.
  • the flashes of light produced by such flash lamps successfully meet present day requirements for satisfactory synchronized flashlight photography, i. e., they are characterized by a relatively high intensity for a prolonged period of time with their peak uniformly occurring at approximately 0.020 of a second following the closure of the electrical circuit through the flash lamp.
  • the curve there illustrated is the time-light intensity curve produced by a representative flash lamp according to the invention.
  • the particular lamp producing this curve consisted of a bulb, commercially known as an A15 bulb, filled with approximately 40 mg. of 1.0 mil regular die-drawn pure aluminum wire and 400mm. of oxygen, and containing a one-half mil diameter tungsten filament embedded in a head of primer material achereinabove.
  • This lamp produced a flash of light having a total of approximately 22,100 lumen seconds. with a peak intensity of approximately 1,000,000 lumens.
  • the time-light intensity curve is more or less flattened or broad in nature, with the peak occurring at approximately 20 milliseconds following energization of the filament.
  • the flash of light produced by the lamp has both the desired prolonged duration and timing characteristics necessary forsatisfactory synchronized flashlight photography.
  • any type of flash lamp When any type of flash lamp is flashed, the resulting products of combustion are deposited principally on the surface of the lamp bulb. Obviously, where these products of combustion are black or otherwise dark in color, there is a possibility that. such a deposit may mask a portion of the actinic light produced by the combustion of the material within the lamp and so prevent the same from emanating from the bulb.
  • a flash lamp according to the present invention employing substantially pure aluminum wire as the combustible material and the improved primer mixture disclosed hereinabove, the products of combustion are principally white in character. Accordingly, there is very little or practically no tendency for the deposit on the bulb to mask or absorb any portion of the light produced by the combustion of the material within the bulb. Thus, substantially all of the actinic light produced within the bulb is allowed to pass out through the bulb, so that maximum utilization of the available actinic light results.
  • a flash lamp according to the invention employing drawn substantially pure aluminum wire as the sole combustible material, will produce a flash of light of relatively prolonged duration having a peak intensity of at least 900,000 lumens or thereabouts, which is sufficiently high to en'- able the taking of satisfactory flashlight pictures.
  • the ignition and combustion of the combustible material within the lamp is effected cording to the preferred composition specified 7 in such a manner that the light peak of every lamp uniformly occurs at approximately 20 milliseconds following energization of the lamp ignition means. Consequently, the lamp will operate satisfactorily with synchronizing mechanism now in general use.
  • the combustible material is in the form of wire, which is generally considered tobe circular in cross-section, it is obvious that the said material may be of any other filamentary form of equivalent cross-sectional area such as, for instance, ribbon. Accordingly, in the appended claims the term wire is intended to include any substantial equivalent, such as ribbon.
  • a flash lamp comprising a sealed envelope containing an oxygenous atmosphere, a quantity of a relatively difficultly ignitable combustible material loosely arranged in said envelope, and ignition means within said envelope comprising an electrical energy translation element and a primer of fulminating material associated therewith, said primer comprising an intimate admixture of substantial amounts of two different powders and an oxidizing agent which readily gives up its oxygen, the two powders being so selected for particle size and composition that one of said powders is very readily ignltable and the other is less readily ignitable but has an appreciably higher heat capacity than the first-mentioned powder, the oxidizing agent and firstmentioned powder causing ignition of the primer with great rapidity so as to violently project burning particles of the second-mentioned powder throughout the envelope, and the said second-mentioned powder carrying sufllcient heat to initiate combustion of the combustible material at points scattered throughout the envelope.
  • a primer composition for flash lamps having combustible material loosely arranged in an enclosing envelope said primer comprising an intimate admixture of substantial amounts of two different powders and an oxidizing agent which readily gives up its oxygen, the two powders being so selected for particle size and composition that one of said powders is very readily ignitable and the other is less readily ignitable but has an appreciably higher heat capacity than the first-mentioned powder, the oxidizing agent and first-mentioned powder causing ignition of the primer with great rapidity so as to violently project burning particles of the secondmentioned powder throughout the envelope, and the said second-mentioned powder carrying sufficient heat to initiate combustion of the combustible material at points scattered throughout the envelope.
  • A-flash lamp comprising a sealed container having an oxidizing atmosphere therein, a quantity of combustible material within said container, and means for igniting said combustible material, said means comprising an electricalenergy translation element and a bead of fulminating substance associated therewith, said bead of fulminating substance containing the proportions of approximately 2.6 grams of one type of zirconium metal powder having a relatively low ignition temperature, 2.6 grams of another type of zirconium metal powder having a larger particle size and a relatively high ignition temperature, 4 grams of chemically pure potassium perchlorate powder, and 5 cc. of a one per cent solution of glue water.
  • substantially pure filamentary aluminum ot a size corresponding to a diameter or the order cl one comprising an electrical energy translation element and a bead or tulminating substance asso ciated therewith, said tulminating substance comprising an admixture of one type of zirconium metal powder having a relatively low ignition temperature, another type of zirconium metal powder having a relatively high ignition temperature and potassium perchlorate powder bonded together with a binder.
  • a flash lamp comprising a sealed container having an oxidizing atmosphere therein, a quantity of combustible material within said container, said combustible material consisting of substantially pure filamentary aluminum of a size corresponding to a diameter of the order or one mil, and ignition means within said container comprising an electrical energy translation element and a bead or tulminatlng substance associated therewith, said bead of fulminating substance containing the proportions of approximately 2.6 grams of one type zirconium metal powder having a relatively low ignition temperature, 2.6 grams of another type of zirconium metal powder having a relatively high ignition temperature, 4 grams of chemically pure potassium perchlorate powder, and 5 cc. of a one per cent solution of glue water.

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Air Bags (AREA)
  • Vessels And Coating Films For Discharge Lamps (AREA)
  • Resistance Heating (AREA)
  • Powder Metallurgy (AREA)
US262209A 1939-03-16 1939-03-16 Flash lamp Expired - Lifetime US2285125A (en)

Priority Applications (7)

Application Number Priority Date Filing Date Title
US262209A US2285125A (en) 1939-03-16 1939-03-16 Flash lamp
US278288A US2280598A (en) 1939-03-16 1939-06-09 Flash lamp
FR866015D FR866015A (fr) 1939-03-16 1940-06-06 Lampes-éclair pour la prise de vues photographiques
GB10075/40A GB541699A (en) 1939-03-16 1940-06-10 Improvements in electric incandescent flash lamps
AT163983D AT163983B (de) 1939-03-16 1947-06-06 Blitzlichtlampe
AT166186D AT166186B (de) 1939-03-16 1947-06-23 Blitzlichtlampe
CH292829D CH292829A (de) 1939-03-16 1947-07-21 Zündmaterial für Blitzlichtlampen.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US262209A US2285125A (en) 1939-03-16 1939-03-16 Flash lamp
US278288A US2280598A (en) 1939-03-16 1939-06-09 Flash lamp

Publications (1)

Publication Number Publication Date
US2285125A true US2285125A (en) 1942-06-02

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US262209A Expired - Lifetime US2285125A (en) 1939-03-16 1939-03-16 Flash lamp
US278288A Expired - Lifetime US2280598A (en) 1939-03-16 1939-06-09 Flash lamp

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Application Number Title Priority Date Filing Date
US278288A Expired - Lifetime US2280598A (en) 1939-03-16 1939-06-09 Flash lamp

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US (2) US2285125A (de)
AT (2) AT163983B (de)
CH (1) CH292829A (de)
FR (1) FR866015A (de)
GB (1) GB541699A (de)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2791111A (en) * 1953-01-15 1957-05-07 Westinghouse Electric Corp Fulminator for photoflash lamps
US2913892A (en) * 1956-08-06 1959-11-24 Union Carbide Corp Photoflash lamp
US3220224A (en) * 1962-05-25 1965-11-30 Westinghouse Electric Corp Photoflash lamp
US3521984A (en) * 1968-08-28 1970-07-28 Sylvania Electric Prod Photoflash lamp
US3625641A (en) * 1969-05-23 1971-12-07 Sylvania Electric Prod Photoflash lamp
US5821451A (en) * 1996-12-19 1998-10-13 Eastman Kodak Company Photoflash particle mixture

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2756577A (en) * 1954-04-07 1956-07-31 Gen Electric Flash lamp and ignition means therefor
US2791114A (en) * 1954-10-29 1957-05-07 Gen Electric Flash lamp and ignition means therefor
DE963940C (de) * 1954-10-29 1957-05-16 Gen Electric Zuendmasse fuer Blitzlichtlampen
US2955447A (en) * 1957-07-16 1960-10-11 Sylvania Electric Prod Photoflash lamp
US3540818A (en) * 1968-08-28 1970-11-17 Sylvania Electric Prod Photoflash lamp
EP1625334B9 (de) 2003-05-21 2012-07-25 Alexza Pharmaceuticals, Inc. Schlag gezündete unabhängige heizeinheit
US7402777B2 (en) 2004-05-20 2008-07-22 Alexza Pharmaceuticals, Inc. Stable initiator compositions and igniters
US7581540B2 (en) 2004-08-12 2009-09-01 Alexza Pharmaceuticals, Inc. Aerosol drug delivery device incorporating percussively activated heat packages

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2791111A (en) * 1953-01-15 1957-05-07 Westinghouse Electric Corp Fulminator for photoflash lamps
US2913892A (en) * 1956-08-06 1959-11-24 Union Carbide Corp Photoflash lamp
US3220224A (en) * 1962-05-25 1965-11-30 Westinghouse Electric Corp Photoflash lamp
US3521984A (en) * 1968-08-28 1970-07-28 Sylvania Electric Prod Photoflash lamp
US3625641A (en) * 1969-05-23 1971-12-07 Sylvania Electric Prod Photoflash lamp
US5821451A (en) * 1996-12-19 1998-10-13 Eastman Kodak Company Photoflash particle mixture

Also Published As

Publication number Publication date
FR866015A (fr) 1941-06-13
GB541699A (en) 1941-12-08
US2280598A (en) 1942-04-21
CH292829A (de) 1953-08-31
AT163983B (de) 1949-09-10
AT166186B (de) 1950-06-26

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