US3791302A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for indirect electrical ignition of combustible powders
Assignee: Individual
•
Filing: 1972-11-10
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Granted: 1974-02-12
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Expires: 1992-11-10
Abstract
Abstract A method and apparatus for the ignition of combustible powders using transparently shielded sources of high intensity light pulses is described. Preferably, low actuating voltage, one shot or consumable photoflash lamps are used to generate a light pulse which is absorbed by the combustible powders and produces ignition. Particularly described is a flashbulb connected to a flashing circuit and a secondary circuit in the flashing circuit for intermittently or continuously conductively monitoring the firing status of the bulb prior to flashing. Particularly preferred combustible powders are nitrocellulose and/or black powders which because of their black color are particularly light absorptive. A photoflash igniter device for practicing the method is particularly described. The igniter and method are particularly useful for generating gas pressure waves which can be used for mass movement and/or forming.
Inventors
- 👤 Leod I Mc
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 11:17
CPC Classifications
F; F21; F21K; F21K5/00; F21K5/02; F23; F23Q; F23Q13/00
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
96 words
The method of igniting combustible powders which comprises: a. providing a finely divided light absorptive explodable combustible powder in spaced, transparently shielded separation from an electrically conductive means for generating a high intensity visible spectrum flash light pulse upon achieving a threshold voltage which has a duration of less than about one second; b. providing means for holding the powder in position adjacent to the shield so as to be light absorptive; and c. providing a voltage above the threshold, thereby exposing the combustible powder to the high intensity pulse so that the powder is ignited.
Claim 2
Independent Claim
96 words
The method of igniting combustible powders which comprises: a. providing a finely divided light absorptive explodable combustible powder in spaced, transparently shielded separation from an electrically conductive means for generating a high intensity visible spectrum flash light pulse upon achieving a threshold voltage which has a duration of less than about one second; b. providing means for holding the powder in position adjacent to the shield so as to be light absorptive; and c. providing a voltage above the threshold, thereby exposing the combustible powder to the high intensity pulse so that the powder is ignited.
Claim 3
Dependent Claim
11 words
The method of claim 1 wherein the powder comprises black powder.
Claim 4
Dependent Claim
15 words
The method of claim 2 wherein a nitrocellulose powder is mixed with the black powder.
Claim 5
Dependent Claim
30 words
The method of claim 1 wherein the powder is provided in contact with the outside surface of a conventional photoflash bulb as the conductive means for generating the light pulse.
Claim 6
Dependent Claim
39 words
The method of claim 1 wherein the conductive means for generating the light pulse is a flash bulb and wherein the powder is sealed in contact with the outside of the surface of the bulb by a sealling means.
Claim 7
Dependent Claim
16 words
The method of claim 5 wherein a light absorbing sealing means for the powder is used.
Claim 8
Dependent Claim
16 words
The method of claim 5 wherein the powder is a mixture of black and nitrocellulose powders.
Claim 9
Dependent Claim
86 words
The article of manufacture useful as an igniter which comprises: a. an electrically conductive transparently shielded means for generating a high intensity visible spectrum flash light pulse of less than one second duration upon achieving a threshold voltage; b. a fully divided light absorptive explodable combustible powder adjacent the surface of the shield opposite the means for generating the light pulse so as to be light ignitable; and c. means for holding the power in position adjacent to the shield so as to be light absorptive.
Claim 10
Dependent Claim
86 words
The article of manufacture useful as an igniter which comprises: a. an electrically conductive transparently shielded means for generating a high intensity visible spectrum flash light pulse of less than one second duration upon achieving a threshold voltage; b. a fully divided light absorptive explodable combustible powder adjacent the surface of the shield opposite the means for generating the light pulse so as to be light ignitable; and c. means for holding the power in position adjacent to the shield so as to be light absorptive.
Claim 11
Dependent Claim
18 words
The article of claim 8 wherein the combustible powder is a mixture of bLack and nitrocellulose gun powders.
Claim 12
Dependent Claim
35 words
The article of claim 8 wherein the means for holding the powder is a covering over the powder and shield so that the powder is held in contact with the outside surface of the shield.
Claim 13
Dependent Claim
31 words
The article of claim 10 wherein the powder is exploded by the light and wherein the cover is elastic and is projectable outward from the shield upon detonation of the powder.
Claim 14
Dependent Claim
32 words
The article of claim 8 wherein the powder is explodable by the light pulse and wherein a solid mass is associated with the powder such that it is movable by the explosion.
Claim 15
Dependent Claim
24 words
The article of claim 8 wherein the light pulse means includes reactive chemicals requiring a low threshold voltage for generation of the light pulse.
Claim 16
Dependent Claim
24 words
The article of claim 8 wherein the light pulse means is a photoflash bulb having a threshold voltage of less than about five volts.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-02-11 | 1977-08-13 | 1978-02-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-11 | 1981-08-13 | 1982-02-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-11 | 1985-08-13 | 1986-02-12 | $7700.00 | Window Closed / Lapsed |