US3724991A - Photoflash lamp - Google Patents
Photoflash lamp Download PDFInfo
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- US3724991A US3724991A US00198547A US3724991DA US3724991A US 3724991 A US3724991 A US 3724991A US 00198547 A US00198547 A US 00198547A US 3724991D A US3724991D A US 3724991DA US 3724991 A US3724991 A US 3724991A
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- Prior art keywords
- percent
- polyvinyl alcohol
- flashlamp
- primer material
- envelope
- Prior art date
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- Expired - Lifetime
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- 239000000463 material Substances 0.000 claims abstract description 57
- 239000004372 Polyvinyl alcohol Substances 0.000 claims abstract description 25
- 229920002451 polyvinyl alcohol Polymers 0.000 claims abstract description 25
- 239000000203 mixture Substances 0.000 claims abstract description 22
- 238000000576 coating method Methods 0.000 claims abstract description 21
- 239000011248 coating agent Substances 0.000 claims abstract description 19
- VKJKEPKFPUWCAS-UHFFFAOYSA-M potassium chlorate Chemical compound [K+].[O-]Cl(=O)=O VKJKEPKFPUWCAS-UHFFFAOYSA-M 0.000 claims abstract description 18
- AXZAYXJCENRGIM-UHFFFAOYSA-J dipotassium;tetrabromoplatinum(2-) Chemical compound [K+].[K+].[Br-].[Br-].[Br-].[Br-].[Pt+2] AXZAYXJCENRGIM-UHFFFAOYSA-J 0.000 claims abstract description 17
- 229910001487 potassium perchlorate Inorganic materials 0.000 claims abstract description 17
- 239000011230 binding agent Substances 0.000 claims abstract description 15
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 claims abstract description 11
- 239000011574 phosphorus Substances 0.000 claims abstract description 11
- 229910052698 phosphorus Inorganic materials 0.000 claims abstract description 11
- 239000002002 slurry Substances 0.000 claims abstract description 11
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 claims abstract description 10
- 229910052719 titanium Inorganic materials 0.000 claims abstract description 10
- 239000010936 titanium Substances 0.000 claims abstract description 10
- 239000007864 aqueous solution Substances 0.000 claims abstract description 5
- 239000008247 solid mixture Substances 0.000 claims description 9
- 229910052751 metal Inorganic materials 0.000 claims description 8
- 239000002184 metal Substances 0.000 claims description 8
- 238000011049 filling Methods 0.000 claims description 6
- 239000004020 conductor Substances 0.000 claims description 2
- 238000004519 manufacturing process Methods 0.000 abstract description 4
- 230000001464 adherent effect Effects 0.000 abstract description 2
- 239000002987 primer (paints) Substances 0.000 description 39
- 239000008199 coating composition Substances 0.000 description 8
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 7
- 239000007789 gas Substances 0.000 description 7
- 229910052760 oxygen Inorganic materials 0.000 description 7
- 239000001301 oxygen Substances 0.000 description 7
- 239000011521 glass Substances 0.000 description 6
- XTEGARKTQYYJKE-UHFFFAOYSA-M Chlorate Chemical compound [O-]Cl(=O)=O XTEGARKTQYYJKE-UHFFFAOYSA-M 0.000 description 4
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 description 4
- 239000007788 liquid Substances 0.000 description 4
- 230000035945 sensitivity Effects 0.000 description 4
- 239000007787 solid Substances 0.000 description 4
- 229910052726 zirconium Inorganic materials 0.000 description 4
- 229910052782 aluminium Inorganic materials 0.000 description 3
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 3
- 239000007900 aqueous suspension Substances 0.000 description 3
- 239000000470 constituent Substances 0.000 description 3
- 239000011888 foil Substances 0.000 description 3
- 238000009472 formulation Methods 0.000 description 3
- 229910052735 hafnium Inorganic materials 0.000 description 3
- VBJZVLUMGGDVMO-UHFFFAOYSA-N hafnium atom Chemical compound [Hf] VBJZVLUMGGDVMO-UHFFFAOYSA-N 0.000 description 3
- 239000006194 liquid suspension Substances 0.000 description 3
- 239000011343 solid material Substances 0.000 description 3
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 238000007792 addition Methods 0.000 description 2
- 239000002585 base Substances 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 2
- 238000004891 communication Methods 0.000 description 2
- 238000004200 deflagration Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000000446 fuel Substances 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- VLTRZXGMWDSKGL-UHFFFAOYSA-N perchloric acid Chemical class OCl(=O)(=O)=O VLTRZXGMWDSKGL-UHFFFAOYSA-N 0.000 description 2
- 238000001953 recrystallisation Methods 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- 238000003860 storage Methods 0.000 description 2
- 239000000725 suspension Substances 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- ZSLUVFAKFWKJRC-IGMARMGPSA-N 232Th Chemical compound [232Th] ZSLUVFAKFWKJRC-IGMARMGPSA-N 0.000 description 1
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 1
- 229910000640 Fe alloy Inorganic materials 0.000 description 1
- 239000004606 Fillers/Extenders Substances 0.000 description 1
- 239000004354 Hydroxyethyl cellulose Substances 0.000 description 1
- 229920000663 Hydroxyethyl cellulose Polymers 0.000 description 1
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 1
- 239000000020 Nitrocellulose Substances 0.000 description 1
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- 229910052776 Thorium Inorganic materials 0.000 description 1
- 240000008042 Zea mays Species 0.000 description 1
- 235000005824 Zea mays ssp. parviglumis Nutrition 0.000 description 1
- 235000002017 Zea mays subsp mays Nutrition 0.000 description 1
- 238000005299 abrasion Methods 0.000 description 1
- 229910052783 alkali metal Inorganic materials 0.000 description 1
- -1 alkali metal chlorates Chemical class 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 239000003125 aqueous solvent Substances 0.000 description 1
- 239000011324 bead Substances 0.000 description 1
- 229910052796 boron Inorganic materials 0.000 description 1
- 229920002678 cellulose Polymers 0.000 description 1
- 239000001913 cellulose Substances 0.000 description 1
- BIJOYKCOMBZXAE-UHFFFAOYSA-N chromium iron nickel Chemical compound [Cr].[Fe].[Ni] BIJOYKCOMBZXAE-UHFFFAOYSA-N 0.000 description 1
- 239000006255 coating slurry Substances 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 235000005822 corn Nutrition 0.000 description 1
- 230000002939 deleterious effect Effects 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 239000002360 explosive Substances 0.000 description 1
- 235000019447 hydroxyethyl cellulose Nutrition 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 239000011777 magnesium Substances 0.000 description 1
- 229910052749 magnesium Inorganic materials 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 125000000956 methoxy group Chemical group [H]C([H])([H])O* 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 229920001220 nitrocellulos Polymers 0.000 description 1
- 239000003960 organic solvent Substances 0.000 description 1
- 239000007800 oxidant agent Substances 0.000 description 1
- VLTRZXGMWDSKGL-UHFFFAOYSA-M perchlorate Inorganic materials [O-]Cl(=O)(=O)=O VLTRZXGMWDSKGL-UHFFFAOYSA-M 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000000375 suspending agent Substances 0.000 description 1
Images
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
- F21K5/023—Ignition devices in photo flash bulbs
- F21K5/026—Ignition devices in photo flash bulbs using mechanical firing, e.g. percussion of a fulminating charge
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
- G03B15/00—Special procedures for taking photographs; Apparatus therefor
- G03B15/02—Illuminating scene
- G03B15/03—Combinations of cameras with lighting apparatus; Flash units
- G03B15/04—Combinations of cameras with non-electronic flash apparatus; Non-electronic flash units
- G03B15/0478—Combinations of photographic apparatus with percussion type flash ignition systems
- G03B15/0484—Constructional details of the flash apparatus
Definitions
- ABSTRACT A percussion-ignitable type flashlamp is disclosed which includes an improved primer material that is more stable in handling during manufacture of the lamp and improves performance of the lamp in operation.
- Said primer material comprises a mixture in percentages by weight of 4-50 percent phosphorus, 3-8 percent potassium chlorate, 6-30 percent potassium perchlorate, and the remainder being titanium, which mixture can be bonded to form a unitary mass with a polyvinyl alcohol binder.
- a slurry of the primer material in an aqueous solution of 87-89 percent hydrolyzed polyvinyl alcohol remains substantially gelfree for long time periods and provides a tough and adherent coating in the lamp.
- the photoflash lamps in general use at present comprise a hermetically sealed light-transmitting envelope usually made of glass and containing a combustion-supporting gas such as oxygen together with a loosely distributed filling of a suitable lightproducing combustible material such as shredded foil of zirconium, aluminum or hafnium, for example,
- the charge of percussively sensitive primer material is located within a readily deformable metal ignition tube sealed within and projecting from one end of a length of glass tubing which forms the lamp envelope and the other end of which is constricted and tipped off.
- the ignition tube extends generally axially of the tubular lamp envelope and opens thereinto, and the primer material is in the form of a coating on a wire anvil supported within the ignition tube and extending approximately axially thereof.
- Flashing of such constructed percussive type photoflash lamps is initiated by a forceful mechanical impact or blow applied against the side of the metal ignition tube to deform it inwardly against the coating of primer material on the wire anvil which causes deflagration of the primer material up through the ignition tube into the lamp envelope where it then ignites the filamentary combustible material disposed therein.
- the known primer materials generally consist of a mixture of a readily combustible fuel such as phosphorus with an oxidizer compound for the fuel such as alkali metal chlorates and perchlorates.
- the primer material also further generally includes a powdered combustible incandescable metal such as zirconium, hafnium, thorium, aluminum, magnesium, boron, silicon or their alloys which upon being heated spews into the envelope to burn the filamentary combustible material when the mixture has been detonated.
- the known primer materials have been prepared as liquid suspensions in an organic or aqueous solvent for coating the anvil member in a percussive type flashlamp, and soluble binders are generally included to provide adhesion of the coating to the anvil member.
- a known organic liquid suspension for the primer material utilizes nitrocellulose as the binder agent and requires careful handling during storage and lamp manufacture to avoid accidental ignition.
- a less sensitive aqueous suspension of the primer material which is known uses hydroxyethyl cellulose or methoxy cellulose as the soluble binder agent.
- a still different problem encountered with aqueous suspensions of the primer material which contain a substantially insoluble constituent such as potassium perchlorate or potassium chlorate occurs from recrystallization of the particular constituent to form oversized lumps in the liquid coating composition.
- the final solid coatings obtained with conventional primer materials further lack adequate adherence to the anvil member and are brittle which has a deleterious effect upon the lamp operation.
- the material For the solid primer composition to operate satisfactor-ily when the lamp is actuated, it becomes necessary for the material to exhibit both the proper ignition sensitivity as well as to ignite the filamentary combustible material properly so as to obtain the desired light output and light peak time. More particularly, the primer material must be sensitive enough in oxygen or another combustion-supporting gas to reliably ignite the flashlamp. Additionally, the blast characteristics of the primer material must distribute hot burning metal sufficiently for the principal combustion reaction which produces the light output from the lamp to take place at a desired light level and time span but without excessive blast velocity. If the blast velocity of the primer material is excessive, then the filamentary combustible material becomes packed in the lamp envelope with subsequent reduction in light output or slower burning rate.
- the improved flashlamp construction of the present invention comprises a hermetically sealed light-transmitting envelope, a quantity of filamentary combustible material loosely distributed within said envelope, a filling of combustion-supporting gas in said envelope,
- percussive-ignition system secured at one end and in communication with the interior of said envelope, said percussive-ignition system including a quantity of primer material comprising a mixture in percentage by weight of 4-50 percent phosphorus, 3-8 percent potassium chlorate, 6-30 percent potassium perchlorate and the remainder being titanium.
- the combined weight percent of potassium chlorate and potassium perchlorate in the primer mixture does not exceed 30 percent in the preferred compositions to maintain a proper balance between safety and handling and sensitivity in lamp operation to provide the aforementioned performance advantages.
- the primer mixture is adhesively bonded to the anvil member with a polyvinyl alcohol binder in the preferred embodiments which provides a tough, flexible and abrasion-resistant coating that does not crack or peel off as readily during lamp manufacture or other handling than was found with conventional primer formulations.
- the coating slurry for the primer materials of the present invention comprises a suspension of the aforementioned solid mixture in an aqueous solution of polyvinyl alcohol. More particularly, the solid mixture can be suspended in equal part by weight of a 2 percent by weight solution of polyvinyl alcohol in water.
- the preferred type of polyvinyl alcohol resin is approximately 87-89 percent hydrolyzed which provides greater flexibility and adhesion in the final coating film as well as greater dispersing power in the aqueous slurry than can be found with a completely hydrolyzed polyvinyl alcohol.
- the dispersion power of polyvinyl alcohol is important in the present coating compositions by reason of the presence of both potassium chlorate and potassium perchlorate which interact in solution by reason of a common ion effect.
- FIGURE is a cross-sectional view partly in elevation of a percussion-type flashlamp of the present invention.
- the flashlamp according to the invention comprises a glass bulb or envelope 1 which, as shown, may be formed of a short length of glass tubing, for example, about inch outside diameter, which is constricted and rounded off at one end as indicated at 2 and closed off thereat by an exhaust tip 3 and is formed at the other or base end 4 with a fused seal 5 about a readily deformable metal ignition tube 6 which may comprise a thin-walled (for example, 0.003- inch wall thickness) tube of a suitable metallic composition such as a nickel-chromium iron alloy, for instance.
- the envelope 1 is made of a glass which is capable of forming a good hermetic seal to the particular metallic material employed for the ignition tube 6.
- the ignition tube 6 which may have an outside diameter of about one-sixteenth inch, for example, is sealed into the base end 4 of the tubular lamp envelope 1 in a position extending longitudinally and preferably axially thereof, and it projects endwise from the envelope end 4 to provide an exposed section 7.
- the ignition tube 6 has a closed outer end 8 and an open inner end 9 which opens into the interior space of the lamp envelope 1 and, as shown, terminates approximately at the inner wall thereof.
- a quantity of filamentary combustible material 10 such as a shredded foil of zirconium, aluminum or hafnium, for example, is loosely distributed within the interior space of the envelope 1 which also contains a filling of a suitable combustionsupporting gas such as oxygen.
- a wire anvil 11 Disposed within the metal ignition tube 6 and extending substantially coaxially therethrough is a wire anvil 11 of a suitable metallic composition of high temperature resistance and low thermal conductivity such as, for example, a stainless steel.
- the wire anvil 11 is suitably held or fastened in place in the ignition tube 6 as by a circumferential indenture 12 of the tube 6 near its outer end which laps over an enlarged head 13 or other suitable protuberance on the outer or lower end of the wire anvil.
- the wire anvil 11 is of a slightly smaller diameter in the outside diameter of the ignition tube 6 so as to be spaced a slight distance, for example, about 0.05 inch or so from the inside wall thereof, and it is provided with a thin coating 14 of a percussively ignitable primer material over an appreciably lengthwise extent of that portion of the wire anvil located within the projecting portion 7 of the ignition tube 6.
- the coating 14 of primer material is of a thickness such as to be spaced a slight distance of around a few thousandths of an inch or so, for example, 0.004 inch, from the inside wall of the ignition tube.
- the wire anvil 1 1 is formed near the open inner or mouth end of the ignition tube 6 with three or more protuberances or lobes 15 spaced apart more or less uniformly around the circumferential extent of the wire anvil and having, along with the head 13 on the Wire anvil, a close sliding fit within the ignition tube.
- the anvil centralizing lobes 15 are of minimal thickness circumferentially of the wire anvil 11 so as to leave substantially unobstructed the annular space between the ignition tube 6 and the wire anvil l 1 for the passage therethrough and into the lamp envelope 1 of the ignited particles of the primer material 14 on ignition and deflagration thereof.
- the anvil centralizing lobes 15 are formed by flattening the wire anvil 1 1 at two closely adjacent points along the length of the anvil and in two different planes at approximately right angles to one another.
- the lamp is also provided with a deflector shield 16 which is located just inwardly of the open inner mouth end 9 of the ignition tube 6 on an inwardly extending portion 17 of the wire anvil 11 that extends into the lamp envelope 1 from the mouth opening 9 of the ignition tube 6.
- the deflector shield 16 can be constituted by a glass bead fusion-sealed to the wire anvil 1 1.
- the coating of primer material in the above embodiment can be applied to the anvil member as a stabilized aqueous suspension of the present invention in various known ways.
- the anvil member can be dipped into the aqueous slurry followed by drying in air or with heat to remove the liquid and produce a solid adhered coating having the desired characteristics previously described.
- the aqueous slurry can be sprayed on the anvil members and thereafter processed to provide a solid coating exhibiting comparable performance.
- a flashlamp comprising a hermetically sealed light-transmitting envelope, a quantity of filamentary combustible material loosely distributed within said envelope, a filling of combustion-supporting gas in said envelope, and a percussive-ignition system secured at one end and in communication with the interior of said envelope, said percussive-ignition system including a quantity of primer material which comprises a solid mixture in percentages by weight of 4-50 percent phosphorus, 3-8 percent potassium chlorate, 6-30 percent potassium perchlorate, and the remainder being titanium.
- a flashlamp comprising a hermetically sealed light-transmitting envelope, a quantity of filamentary combustible material loosely distributed within said envelope, a filling of a combustion-supporting gas in said envelope, and a percussive-ignition system for said lam corn risin a readil deformable metal i ition tubti sealeg in ai id projecting from one end of s i d envelope enclosed off at its outer end, a wire anvil of a high temperature resistant and low thermal-conducting material disposed within and substantially coaxial with said ignition tube, said wire anvil being coated with a quantity of primer material which comprises a mixture in percentages by weight of 4-50 percent phosphorus, 3-8 percent potassium chlorate, 6-30 percent potassium perchlorate, and the remainder being titanium.
- a primer material which comprises a solid mixture having in percentages by weight 4-50 percent phosphorus, 3-8 percent potassium chlorate, 6-30 percent potassium perchlorate, and the remainder being titanium which is bonded into a unitary mass with a polyvinyl alcohol binder.
- a stabilized slurry of primer material which comprises a solid mixture containing in percentages by weight of said solid mixture 4-50 percent phosphorus, 3-8 percent potassium chlorate, 6-30 percent potassium perchlorate, and the remainder being titanium with said mixture being suspended in an aqueous solution of polyvinyl alcohol.
Abstract
A percussion-ignitable type flashlamp is disclosed which includes an improved primer material that is more stable in handling during manufacture of the lamp and improves performance of the lamp in operation. Said primer material comprises a mixture in percentages by weight of 4-50 percent phosphorus, 3-8 percent potassium chlorate, 6-30 percent potassium perchlorate, and the remainder being titanium, which mixture can be bonded to form a unitary mass with a polyvinyl alcohol binder. A slurry of the primer material in an aqueous solution of 87-89 percent hydrolyzed polyvinyl alcohol remains substantially gel-free for long time periods and provides a tough and adherent coating in the lamp.
Description
United States Patent 1 Schupp [54] PHOTOFLASH LAMP Lewis J. Schupp, Chesterland, Ohio [73] Assignee: General Electric Company, Schenectady, N.Y.
22 Filed: Nov. 15,1971
21 Appl.No.: 198,547
[75] Inventor:
11 3,724,991 Apr. 3, 1973 Primary Examiner-Carroll B. Dority, Jr. Attorney-John F. McDevitt et a1.
[5 7] ABSTRACT A percussion-ignitable type flashlamp is disclosed which includes an improved primer material that is more stable in handling during manufacture of the lamp and improves performance of the lamp in operation. Said primer material comprises a mixture in percentages by weight of 4-50 percent phosphorus, 3-8 percent potassium chlorate, 6-30 percent potassium perchlorate, and the remainder being titanium, which mixture can be bonded to form a unitary mass with a polyvinyl alcohol binder. A slurry of the primer material in an aqueous solution of 87-89 percent hydrolyzed polyvinyl alcohol remains substantially gelfree for long time periods and provides a tough and adherent coating in the lamp.
10 Claims, 1 Drawing Figure PATENTED R 3 I975 ITlVTWL'OT. Lewis J. Schupp 's A t tor-neg PHOTOFLASH LAMP BACKGROUND OF THE INVENTION This invention relates in general to photoflash lamps and more particularly to those of the so-called percussion-ignitable type. The photoflash lamps in general use at present comprise a hermetically sealed light-transmitting envelope usually made of glass and containing a combustion-supporting gas such as oxygen together with a loosely distributed filling of a suitable lightproducing combustible material such as shredded foil of zirconium, aluminum or hafnium, for example,
which upon ignition produces a high intensity flash of actinic light. Suitable ignition means are generally provided in the lamp to initiate the flashing thereof. In the percussive-ignition type photoflash lamps in general use at present, the charge of percussively sensitive primer material is located within a readily deformable metal ignition tube sealed within and projecting from one end of a length of glass tubing which forms the lamp envelope and the other end of which is constricted and tipped off. The ignition tube extends generally axially of the tubular lamp envelope and opens thereinto, and the primer material is in the form of a coating on a wire anvil supported within the ignition tube and extending approximately axially thereof. Flashing of such constructed percussive type photoflash lamps is initiated by a forceful mechanical impact or blow applied against the side of the metal ignition tube to deform it inwardly against the coating of primer material on the wire anvil which causes deflagration of the primer material up through the ignition tube into the lamp envelope where it then ignites the filamentary combustible material disposed therein.
The known primer materials generally consist of a mixture of a readily combustible fuel such as phosphorus with an oxidizer compound for the fuel such as alkali metal chlorates and perchlorates. The primer material also further generally includes a powdered combustible incandescable metal such as zirconium, hafnium, thorium, aluminum, magnesium, boron, silicon or their alloys which upon being heated spews into the envelope to burn the filamentary combustible material when the mixture has been detonated. The known primer materials have been prepared as liquid suspensions in an organic or aqueous solvent for coating the anvil member in a percussive type flashlamp, and soluble binders are generally included to provide adhesion of the coating to the anvil member. A known organic liquid suspension for the primer material utilizes nitrocellulose as the binder agent and requires careful handling during storage and lamp manufacture to avoid accidental ignition. A less sensitive aqueous suspension of the primer material which is known uses hydroxyethyl cellulose or methoxy cellulose as the soluble binder agent.
Various problems exist with the known primer materials both in the preparation and application as a coating upon the anvil member or in the operation of a flashlamp having such coatings. The liquid suspensions have been found unstable in that the suspended material settled out or aggregated so as to preclude being able to obtain a uniform liquid coating of the primer material on the anvil member. In a dip method of coating, it was also found that solid materials from the coating composition adhered to the sides of the container holding the coating composition with said adhered material proving to be unwettable when additions of the liquid composition were supplied to the container. A still different problem encountered with aqueous suspensions of the primer material which contain a substantially insoluble constituent such as potassium perchlorate or potassium chlorate occurs from recrystallization of the particular constituent to form oversized lumps in the liquid coating composition. The final solid coatings obtained with conventional primer materials further lack adequate adherence to the anvil member and are brittle which has a deleterious effect upon the lamp operation.
For the solid primer composition to operate satisfactor-ily when the lamp is actuated, it becomes necessary for the material to exhibit both the proper ignition sensitivity as well as to ignite the filamentary combustible material properly so as to obtain the desired light output and light peak time. More particularly, the primer material must be sensitive enough in oxygen or another combustion-supporting gas to reliably ignite the flashlamp. Additionally, the blast characteristics of the primer material must distribute hot burning metal sufficiently for the principal combustion reaction which produces the light output from the lamp to take place at a desired light level and time span but without excessive blast velocity. If the blast velocity of the primer material is excessive, then the filamentary combustible material becomes packed in the lamp envelope with subsequent reduction in light output or slower burning rate.
SUMMARY OF THE INVENTION material, it becomes possible to achieve a mean light output of approximately 460 zonal lumen-seconds from flashlamps containing 18 milligrams of a zirconium filamentary material and 4.5 cc of oxygen compared with the 19 milligrams of said foil and 5 cc of oxygen being utilized in the conventional flashlamps.
The improved flashlamp construction of the present invention comprises a hermetically sealed light-transmitting envelope, a quantity of filamentary combustible material loosely distributed within said envelope, a filling of combustion-supporting gas in said envelope,
.and a percussive-ignition system secured at one end and in communication with the interior of said envelope, said percussive-ignition system including a quantity of primer material comprising a mixture in percentage by weight of 4-50 percent phosphorus, 3-8 percent potassium chlorate, 6-30 percent potassium perchlorate and the remainder being titanium. The combined weight percent of potassium chlorate and potassium perchlorate in the primer mixture does not exceed 30 percent in the preferred compositions to maintain a proper balance between safety and handling and sensitivity in lamp operation to provide the aforementioned performance advantages. Likewise, the primer mixture is adhesively bonded to the anvil member with a polyvinyl alcohol binder in the preferred embodiments which provides a tough, flexible and abrasion-resistant coating that does not crack or peel off as readily during lamp manufacture or other handling than was found with conventional primer formulations.
The coating slurry for the primer materials of the present invention comprises a suspension of the aforementioned solid mixture in an aqueous solution of polyvinyl alcohol. More particularly, the solid mixture can be suspended in equal part by weight of a 2 percent by weight solution of polyvinyl alcohol in water. The preferred type of polyvinyl alcohol resin is approximately 87-89 percent hydrolyzed which provides greater flexibility and adhesion in the final coating film as well as greater dispersing power in the aqueous slurry than can be found with a completely hydrolyzed polyvinyl alcohol. The dispersion power of polyvinyl alcohol is important in the present coating compositions by reason of the presence of both potassium chlorate and potassium perchlorate which interact in solution by reason of a common ion effect. While the greater solu bility of the chlorate serves to reduce the solubility of the perchlorate and minimize recrystallization of the latter material which can produce large lumps in the coating composition, it becomes necessary to have these materials uniformly dispersed in the coating composition for the desired effect to take place.
BRIEF DESCRIPTION OF THE DRAWING In the drawing, the single FIGURE is a cross-sectional view partly in elevation of a percussion-type flashlamp of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawing, the flashlamp according to the invention comprises a glass bulb or envelope 1 which, as shown, may be formed of a short length of glass tubing, for example, about inch outside diameter, which is constricted and rounded off at one end as indicated at 2 and closed off thereat by an exhaust tip 3 and is formed at the other or base end 4 with a fused seal 5 about a readily deformable metal ignition tube 6 which may comprise a thin-walled (for example, 0.003- inch wall thickness) tube of a suitable metallic composition such as a nickel-chromium iron alloy, for instance. The envelope 1 is made of a glass which is capable of forming a good hermetic seal to the particular metallic material employed for the ignition tube 6. As shown, the ignition tube 6 which may have an outside diameter of about one-sixteenth inch, for example, is sealed into the base end 4 of the tubular lamp envelope 1 in a position extending longitudinally and preferably axially thereof, and it projects endwise from the envelope end 4 to provide an exposed section 7. The ignition tube 6 has a closed outer end 8 and an open inner end 9 which opens into the interior space of the lamp envelope 1 and, as shown, terminates approximately at the inner wall thereof. A quantity of filamentary combustible material 10 such as a shredded foil of zirconium, aluminum or hafnium, for example, is loosely distributed within the interior space of the envelope 1 which also contains a filling of a suitable combustionsupporting gas such as oxygen.
Disposed within the metal ignition tube 6 and extending substantially coaxially therethrough is a wire anvil 11 of a suitable metallic composition of high temperature resistance and low thermal conductivity such as, for example, a stainless steel. The wire anvil 11 is suitably held or fastened in place in the ignition tube 6 as by a circumferential indenture 12 of the tube 6 near its outer end which laps over an enlarged head 13 or other suitable protuberance on the outer or lower end of the wire anvil. As shown, the wire anvil 11 is of a slightly smaller diameter in the outside diameter of the ignition tube 6 so as to be spaced a slight distance, for example, about 0.05 inch or so from the inside wall thereof, and it is provided with a thin coating 14 of a percussively ignitable primer material over an appreciably lengthwise extent of that portion of the wire anvil located within the projecting portion 7 of the ignition tube 6. The coating 14 of primer material is of a thickness such as to be spaced a slight distance of around a few thousandths of an inch or so, for example, 0.004 inch, from the inside wall of the ignition tube.
To aid in supporting the wire anvil 11 substantially coaxially within the ignition tube 6 and insure clearance between the coating 14 of primer material in the inside wall of the ignition tube 6, the wire anvil 1 1 is formed near the open inner or mouth end of the ignition tube 6 with three or more protuberances or lobes 15 spaced apart more or less uniformly around the circumferential extent of the wire anvil and having, along with the head 13 on the Wire anvil, a close sliding fit within the ignition tube. The anvil centralizing lobes 15 are of minimal thickness circumferentially of the wire anvil 11 so as to leave substantially unobstructed the annular space between the ignition tube 6 and the wire anvil l 1 for the passage therethrough and into the lamp envelope 1 of the ignited particles of the primer material 14 on ignition and deflagration thereof. In the particular case illustrated, the anvil centralizing lobes 15 are formed by flattening the wire anvil 1 1 at two closely adjacent points along the length of the anvil and in two different planes at approximately right angles to one another. The lamp is also provided with a deflector shield 16 which is located just inwardly of the open inner mouth end 9 of the ignition tube 6 on an inwardly extending portion 17 of the wire anvil 11 that extends into the lamp envelope 1 from the mouth opening 9 of the ignition tube 6. The deflector shield 16 can be constituted by a glass bead fusion-sealed to the wire anvil 1 1.
The coating of primer material in the above embodiment can be applied to the anvil member as a stabilized aqueous suspension of the present invention in various known ways. For example, the anvil member can be dipped into the aqueous slurry followed by drying in air or with heat to remove the liquid and produce a solid adhered coating having the desired characteristics previously described. Altemately, the aqueous slurry can be sprayed on the anvil members and thereafter processed to provide a solid coating exhibiting comparable performance.
An example of a coating composition made in accordance with the present invention which is both safe to handle and exhibits the desired sensitivity in lamp operation is as follows:
Potassium chlorate 3 Water (with 2% polyvinyl alcohol binder) 50 This primer suspension can be mixed in a conventional manner to produce a smooth, even blend of the constituents which is stable in storage over long time periods. All solid materials except the chlorate can have a particle range from a fine mesh size to micron size which insures a smooth and uniform primer coating. By changing the ratio of the solid materials in the primer within the ratios of the weight ratios above specified, it is possible to make the final percussively ignitable material more or less explosive and more or less sensitive in air or oxygen. The formulation can be varied to make the final primer safer to handle wet or dry and still be made sensitive enough in oxygen or some other combustion-supporting gas to reliably ignite the flashlamp. Consequently, the proper balance between safety and sensitivity will specify the particular formulation best fitted for a given application.
While the best mode of carrying out the present invention has been set forth above, it will be understood that additions, changes and modifications may be made thereto without departing from the spirit and scope of the invention as defined in the appended claims. For example, it will be apparent that extenders such as finely divided silica and suspending agents can be added to the aqueous slurry for greater stability if the need arises. Likewise, defoamers can be added to the aqueous slurry which may facilitate more immediate application of a freshly prepared coating composition. It is intended to limit the present invention, therefore, only to the scope of the following claims.
What I claim as new and desire to secure by Letters Patent of the United States is:
l. A flashlamp comprising a hermetically sealed light-transmitting envelope, a quantity of filamentary combustible material loosely distributed within said envelope, a filling of combustion-supporting gas in said envelope, and a percussive-ignition system secured at one end and in communication with the interior of said envelope, said percussive-ignition system including a quantity of primer material which comprises a solid mixture in percentages by weight of 4-50 percent phosphorus, 3-8 percent potassium chlorate, 6-30 percent potassium perchlorate, and the remainder being titanium.
2. A flashlamp as in claim 1 wherein the combined weight percent of potassium chlorate and potassium perchlorate does not exceed 30 percent.
3. A flashlamp as in claim 1 wherein the primer material is bonded into a unitary mass with a polyvinyl alcohol binder.
4. A flashlamp comprising a hermetically sealed light-transmitting envelope, a quantity of filamentary combustible material loosely distributed within said envelope, a filling of a combustion-supporting gas in said envelope, and a percussive-ignition system for said lam corn risin a readil deformable metal i ition tubti sealeg in ai id projecting from one end of s i d envelope enclosed off at its outer end, a wire anvil of a high temperature resistant and low thermal-conducting material disposed within and substantially coaxial with said ignition tube, said wire anvil being coated with a quantity of primer material which comprises a mixture in percentages by weight of 4-50 percent phosphorus, 3-8 percent potassium chlorate, 6-30 percent potassium perchlorate, and the remainder being titanium.
5. A flashlamp as in claim 4 wherein the combined weight percent of potassium chlorate and potassium perchlorate does not exceed 30 percent.
6. A flashlamp as in claim 4 wherein the coating of primermaterial is bonded to the anvil with a polyvinyl alcohol binder.
7. A flashlamp as in claim 6 wherein the polyvinyl alcohol binder is approximately 87-89 percent hydrolyzed polyvinyl alcohol.
8. A primer material which comprises a solid mixture having in percentages by weight 4-50 percent phosphorus, 3-8 percent potassium chlorate, 6-30 percent potassium perchlorate, and the remainder being titanium which is bonded into a unitary mass with a polyvinyl alcohol binder.
9. A stabilized slurry of primer material which comprises a solid mixture containing in percentages by weight of said solid mixture 4-50 percent phosphorus, 3-8 percent potassium chlorate, 6-30 percent potassium perchlorate, and the remainder being titanium with said mixture being suspended in an aqueous solution of polyvinyl alcohol.
10. A stabilized slurry as in claim 9 wherein the polyvinyl alcohol is approximately 87-89 percent hydrolyzed.
Claims (9)
- 2. A flashlamp as in claim 1 wherein the combined weight percent of potassium chlorate and potassium perchlorate does not exceed 30 percent.
- 3. A flashlamp as in claim 1 wherein the primer material is bonded into a unitary mass with a polyvinyl alcohol binder.
- 4. A flashlamp comprising a hermetically sealed light-transmitting envelope, a quantity of filamentary combustible material loosely distributed within said envelope, a filling of a combustion-supporting gas in said envelope, and a percussive-ignition system for said lamp comprising a readily deformable metal ignition tube sealed in and projecting from one end of said envelope enclosed off at its outer end, a wire anvil of a high temperature resistant and low thermal-conducting material disposed within and substantially coaxial with said ignition tube, said wire anvil being coated with a quantity of primer material which comprises a mixture in percentages by weight of 4-50 percent phosphorus, 3-8 percent potassium chlorate, 6-30 percent potassium perchlorate, and the remainder being titanium.
- 5. A flashlamp as in claim 4 wherein the combined weight percent of potassium chlorate and potassium perchlorate does not exceed 30 percent.
- 6. A flashlamp as in claim 4 wherein the coating of primer material is bonded to the anvil with a polyvinyl alcohol binder.
- 7. A flashlamp as in claim 6 wherein the polyvinyl alcohol binder is approximately 87-89 percent hydrolyzed polyvinyl alcohol.
- 8. A primer material which comprises a solid mixture having in percentages by weight 4-50 percent phosphorus, 3-8 percent potassium chlorate, 6-30 percent potassium perchlorate, and the remainder being titanium which is bonded into a unitary mass with a polyvinyl alcohol binder.
- 9. A stabilized slurry of primer material which comprises a solid mixture containing in percentages by weight of said solid mixture 4-50 percent phosphorus, 3-8 percent potassium chlorate, 6-30 percent potassium perchlorate, and the remainder being titanium with said mixture being suspended in an aqueous solution of polyvinyl alcohol.
- 10. A stabilized slurry as in claim 9 wherein the polyvinyl alcohol is approximately 87-89 percent hydrolyzed.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US19854771A | 1971-11-15 | 1971-11-15 |
Publications (1)
Publication Number | Publication Date |
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US3724991A true US3724991A (en) | 1973-04-03 |
Family
ID=22733840
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US00198547A Expired - Lifetime US3724991A (en) | 1971-11-15 | 1971-11-15 | Photoflash lamp |
Country Status (1)
Country | Link |
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US (1) | US3724991A (en) |
Cited By (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3893798A (en) * | 1972-12-15 | 1975-07-08 | Gen Electric | Photoflash lamp |
US3904451A (en) * | 1973-11-28 | 1975-09-09 | Westinghouse Electric Corp | Method for preparing primer for percussion-ignitable flash lamp |
US3969067A (en) * | 1975-03-12 | 1976-07-13 | General Electric Company | Photoflash lamp |
US3972673A (en) * | 1974-09-23 | 1976-08-03 | General Electric Company | Photoflash lamp |
US4025285A (en) * | 1975-10-28 | 1977-05-24 | Gte Sylvania Incorporated | Photoflash lamp |
US4078881A (en) * | 1976-12-16 | 1978-03-14 | General Electric Company | Photoflash lamp |
US4128858A (en) * | 1975-04-14 | 1978-12-05 | General Electric Company | Multiple flashlamp system |
US5451277A (en) * | 1991-05-09 | 1995-09-19 | Aerojet-General Corporation | Preparing solid energetic compositions from coated particles and liquid oxidizers |
US20040234914A1 (en) * | 2003-05-21 | 2004-11-25 | Alexza Molecular Delivery Corporation | Percussively ignited or electrically ingnited self-contained heating unit and drug-supply unit employing same |
US20050258159A1 (en) * | 2004-05-20 | 2005-11-24 | Alexza Molecular Delivery Corporation | 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 |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3511586A (en) * | 1968-08-08 | 1970-05-12 | Sylvania Electric Prod | Photoflash lamp and combination of matter |
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 |
-
1971
- 1971-11-15 US US00198547A patent/US3724991A/en not_active Expired - Lifetime
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3511586A (en) * | 1968-08-08 | 1970-05-12 | Sylvania Electric Prod | Photoflash lamp and combination of matter |
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 |
Cited By (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3893798A (en) * | 1972-12-15 | 1975-07-08 | Gen Electric | Photoflash lamp |
US3904451A (en) * | 1973-11-28 | 1975-09-09 | Westinghouse Electric Corp | Method for preparing primer for percussion-ignitable flash lamp |
US3972673A (en) * | 1974-09-23 | 1976-08-03 | General Electric Company | Photoflash lamp |
US3969067A (en) * | 1975-03-12 | 1976-07-13 | General Electric Company | Photoflash lamp |
US4128858A (en) * | 1975-04-14 | 1978-12-05 | General Electric Company | Multiple flashlamp system |
US4025285A (en) * | 1975-10-28 | 1977-05-24 | Gte Sylvania Incorporated | Photoflash lamp |
US4078881A (en) * | 1976-12-16 | 1978-03-14 | General Electric Company | Photoflash lamp |
US5451277A (en) * | 1991-05-09 | 1995-09-19 | Aerojet-General Corporation | Preparing solid energetic compositions from coated particles and liquid oxidizers |
US20040234914A1 (en) * | 2003-05-21 | 2004-11-25 | Alexza Molecular Delivery Corporation | Percussively ignited or electrically ingnited self-contained heating unit and drug-supply unit employing same |
US8387612B2 (en) | 2003-05-21 | 2013-03-05 | Alexza Pharmaceuticals, Inc. | Self-contained heating unit and drug-supply unit employing same |
US8991387B2 (en) | 2003-05-21 | 2015-03-31 | Alexza Pharmaceuticals, Inc. | Self-contained heating unit and drug-supply unit employing same |
US9370629B2 (en) | 2003-05-21 | 2016-06-21 | Alexza Pharmaceuticals, Inc. | Self-contained heating unit and drug-supply unit employing same |
US20050258159A1 (en) * | 2004-05-20 | 2005-11-24 | Alexza Molecular Delivery Corporation | Stable initiator compositions and igniters |
US7402777B2 (en) | 2004-05-20 | 2008-07-22 | Alexza Pharmaceuticals, Inc. | Stable initiator compositions and igniters |
US7923662B2 (en) | 2004-05-20 | 2011-04-12 | 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 |
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