FLAT ELECTRIC MATCH
A flat electric match includes a substrate having a surface. A first electrical lead and a second electrical lead each having an end, are carried by the substrate on the surface. The ends of the electrical leads are spaced apart on the surface. A bridge wire is coupled between the ends of the electrical leads and carried by the substrate on the surface. A pyrotechnic material is carried by the substrate on the surface, with at least a portion of the pyrotechnic material contacting the bridge wire.
This invention relates to pyrotechnic devices.
More particularly, the present invention relates to electric matches.
BACKGROUND OF THE INVENTIONElectric matches are well known in the art of explosives and pyrotechnic devices. An electric match is most often employed by insertion into a fuse, detonator, or charge and is the ignition source. The electric match ignites the detonating charge or the fuse, which then ignites the main charge or pyrotechnic device. Ignition of the electric match is accomplished by providing an electrical charge across two insulated wires coupled at an end by a resistive bridge wire. The bridge wire is heated by the electrical current which, in turn, ignites a pyrotechnic coating. The ignition of the pyrotechnic coating then ignites a fuse, detonating charge, and the like.
Electric matches are commonly formed by dipping the end of the leads with the bridge wire into a slurry of pyrotechnic material. While an effective and inexpensive device, an electric match has some problems. The bridge wire is generally soldered to the ends of the two leads, forming weak points. The leads are typically supported by an insulating header through which the ends of the leads extend and which separates and holds the leads in position relative one another. However, the loose ends between which the bridge wire is connected can flex and move. During fabrication or use, this flexing and moving of the ends of the leads can adversely effect the attachment and electrical coupling of the bridge wire. If either end of the bridge wire is separated or otherwise electrically isolated from the associated lead, such as during the dipping process, the device is rendered inoperable.
Another problem associated with electric matches is that the amount of pyrotechnic material coating the bridge wire is very limited. The fragility of the bridge wire limits its size and the amount of pyrotechnic material that can be carried. Due to this limitation, electric matches are employed to ignite a secondary or detonating charge, and are not themselves a detonating charge.
It would be highly advantageous, therefore, to remedy the foregoing and other deficiencies inherent in the prior art.
An object of the present invention is to provide a more robust and reliable electric match.
Another object of the present invention is to provide an electric match that can carry a larger pyrotechnic charge.
Yet another object of the present invention is to provide an electric match which can support multiple layers of pyrotechnic material.
And another object of the present invention is to provide an electric match that can employ pyrotechnic materials on opposing sides.
SUMMARY OF THE INVENTIONBriefly, to achieve the desired objects and advantages of the instant invention, provided is a flat electric match. The flat electric match includes a substrate having a surface, a first electrical lead having an end, and a second electrical lead having an end. The first electrical lead and the second electrical lead are carried by the substrate on the surface. The end of the first electrical lead is spaced from the end of the second electrical lead. A bridge wire is coupled between the ends of the first electrical lead and the second electrical lead. The bridge wire is carried by the substrate on the surface. A pyrotechnic material is carried by the substrate on the surface with at least a portion of the pyrotechnic material contacting the bridge wire.
In another aspect, a second bridge wire is electrical coupled to and extends between the first electrical lead and the second electrical lead, spaced from the bridge wire, and contacting at least a portion of the pyrotechnic material
In yet another aspect, an electric power source is coupled to second ends of the first lead and the second lead, supplying an electric current to the bridge wire on demand.
In a further aspect of the present invention, the flat electric match includes the substrate having a second surface with a third electrical lead having an end thereon. The third electrical lead is carried by the substrate on the second surface. A fourth electrical lead having an end is carried by the substrate on the second surface with the end of the third electrical lead spaced from the end of the fourth electrical lead. A second bridge wire is coupled between the third electrical lead and the fourth electrical lead. The second bridge wire is carried by the substrate on the second surface. A second pyrotechnic material is carried by the substrate on the second surface with at least a portion contacting the second bridge wire.
In yet a further aspect of the present invention, the flat electric match includes the substrate having a second surface. At least one bridge wire is carried by the substrate on the second surface with the at least one bridge wire electrically coupled between the first electrical lead and the second electrical lead. A second pyrotechnic material is carried by the substrate on the second surface, with at least a portion of the second pyrotechnic material contacting the at least one bridge wire.
Specific objects and advantages of the instant invention will become readily apparent to those skilled in the art from the following detailed description of a preferred embodiment thereof taken in conjunction with the drawings, in which:
Turning now to the drawings in which like reference characters indicate corresponding elements throughout the several views, attention is first directed to
Leads 15 and 16, in this embodiment, are conductive wires 30 having an insulating layer 32 and extend along surface 14, providing support along their entire length. Bridge wire 25 is also supported by surface 14 of substrate 12, thus removing any potential for flexing or movement of leads 15 and 16 relative bridge wire 25. It is noted here that while leads 15 and 16 can be insulated wires carried by substrate 12 on surface 14, the leads can also be formed on the substrate by depositing, sputtering, painting, embedding, printing, etc., conductive materials on surface 14. This is also the case for bridge wire 25. It should also be noted that leads 15 and 16 need not be positioned in parallel. It is sufficient that ends 20 and 22 are spaced apart but in sufficient proximity to be electrically coupled by bridge wire 25.
A pyrotechnic material 35 can then be applied to bridge wire 25 by dropping, brushing or otherwise covering, or at least contacting, a portion of bridge wire 25 with a slurry of pyrotechnic material 35. There are a multitude of different pyrotechnic materials known in the art, any of which can be used in the present invention. Due to the large number and well known nature and fabrication of different pyrotechnic materials and compositions, a detailed description thereof has been omitted from the present disclosure. The amount of material 35 added is not limited by the size or strength of bridge wire 25, as the weight and volume of the pyrotechnic charge is fully supported by surface 14 of substrate 12. Once a layer of material has dried or hardened, subsequent layers can be applied if desired to form a pyrotechnic charge of multiple layers 35a, 35b, and 35c, as illustrated in
Turning now to
Turning now to
A pyrotechnic material 132 can then be applied to bridge wires 124 and 125 by dropping, brushing or otherwise covering, or at least contacting, a portion of bridge wires 124 and 125 with a slurry of pyrotechnic material 132. The amount of material 132 added is not limited by the size or strength of bridge wires 124 and 125, as the weight and volume of the pyrotechnic charge is fully supported by surface 114 of substrate 112. Once a layer of material has dried or hardened, subsequent layers can be applied if desired to form a pyrotechnic charge of multiple layers.
Referring now to
As another embodiment, the second electrical circuit on surface 134 can be formed of one or more bridge wires 144 and 145 coupled to leads 115 and 116 of the electrical circuit on surface 114 by interconnecting electrical vias (known in the circuit board industry) that run through substrate 112. In this manner, bridge wires 144 and 145 are coupled by vias to leads 115 and 116 to form an electrical circuit when completed by an electrical power source such as a battery or the like, allowing current to flow through bridge wires 144 and 145 on demand.
A pyrotechnic material 150 can then be applied to bridge wires 144 and 145 by dropping, brushing or otherwise covering, or at least contacting, a portion of bridge wires 144 and 145 with a slurry of pyrotechnic material 150. Materials 150 can be the same as or different than pyrotechnic material 132 carried on surface 114. In this manner, match 110 can have multiple pyrotechnic ignitions of different materials at the same or different times, as well as an increased volume of materials.
Various changes and modifications to the embodiments herein chosen for purposes of illustration will readily occur to those skilled in the art. To the extent that such modifications and variations do not depart from the spirit of the invention, they are intended to be included within the scope thereof, which is assessed only by a fair interpretation of the following claims.
Having fully described the invention in such clear and concise terms as to enable those skilled in the art to understand and practice the same, the invention claimed is:
Claims
1. A flat electric match comprising:
- a substrate having a surface;
- a first electrical lead having an end, the first electrical lead carried by the substrate on the surface;
- a second electrical lead having an end, the second electrical lead carried by the substrate on the surface with the end of the first electrical lead spaced from the end of the second electrical lead;
- a bridge wire coupled between the first electrical lead and the second electrical lead, the bridge wire carried by the substrate on the surface; and
- a pyrotechnic material carried by the substrate on the surface, at least a portion of the pyrotechnic material contacting the bridge wire.
2. A flat electric match as claimed in claim 1 further including a second bridge wire electrical coupled to and extending between the first electrical lead and the second electrical lead, spaced from the bridge wire, and contacting at least a portion of the pyrotechnic material.
3. A flat electric match as claimed in claim 1 wherein the first lead and the second lead are insulated wires.
4. A flat electric match as claimed in claim 1 wherein the first lead and the second lead are formed on the surface of the substrate.
5. A flat electric match as claimed in claim 1 wherein the pyrotechnic material is multilayered.
6. A flat electric match as claimed in claim 1 further comprising:
- the substrate having a second surface;
- a third electrical lead having an end, the third electrical lead carried by the substrate on the second surface;
- a fourth electrical lead having an end, the fourth electrical lead carried by the substrate on the second surface with the end of the third electrical lead spaced from the end of the fourth electrical lead;
- a second bridge wire coupled between the third electrical lead and the fourth electrical lead, the second bridge wire carried by the substrate on the second surface; and
- a second pyrotechnic material carried by the substrate on the second surface, at least a portion of the second pyrotechnic material contacting the second bridge wire.
7. A flat electric match as claimed in claim 6 further including a third bridge wire electrical coupled to and extending between the first electrical lead and the second electrical lead, spaced from the bridge wire, and contacting at least a portion of the pyrotechnic material, and a fourth bridge wire electrical coupled to and extending between the third electrical lead and the fourth electrical lead spaced from the second bridge wire, and contacting at least a portion of the second pyrotechnic material.
8. A flat electric match as claimed in claim 1 further comprising:
- the substrate having a second surface;
- at least one bridge wire carried by the substrate on the second surface, the at least one bridge wire electrically coupled between the first electrical lead and the second electrical lead; and
- a second pyrotechnic material carried by the substrate on the second surface, at least a portion of the second pyrotechnic material contacting the at least one bridge wire.
9. A flat electric match comprising:
- a substrate having a surface;
- a first electrical lead having a first end and a second end, the first electrical lead carried by the substrate on the surface;
- a second electrical lead having a first end and a second end, the second electrical lead carried by the substrate on the surface with the first end of the first electrical lead spaced from the first end of the second electrical lead;
- a bridge wire coupled between the first electrical lead and the second electrical lead, the bridge wire carried by the substrate on the surface;
- a pyrotechnic material carried by the substrate on the surface, at least a portion of the pyrotechnic material contacting the bridge wire; and
- an electric power source coupled to the second ends of the first lead and the second lead, supplying an electric current to the bridge wire on demand.
10. A flat electric match as claimed in claim 9 further including a second bridge wire electrical coupled to and extending between the first electrical lead and the second electrical lead, spaced from the bridge wire, and contacting at least a portion of the pyrotechnic material.
11. A flat electric match as claimed in claim 9 wherein the first lead and the second lead are insulated wires.
12. A flat electric match as claimed in claim 9 wherein the first lead and the second lead are formed on the surface of the substrate.
13. A flat electric match as claimed in claim 9 wherein the pyrotechnic material is multilayered.
14. A flat electric match as claimed in claim 9 further comprising:
- the substrate having a second surface;
- a third electrical lead having a first end and a second end, the third electrical lead carried by the substrate on the second surface;
- a fourth electrical lead having a first end and a second end, the fourth electrical lead carried by the substrate on the second surface with the first end of the third electrical lead spaced from the first end of the fourth electrical lead;
- a second bridge wire coupled between the third electrical lead and the fourth electrical lead, the second bridge wire carried by the substrate on the second surface;
- a second pyrotechnic material carried by the substrate on the second surface, at least a portion of the pyrotechnic material contacting the second bridge wire; and
- an electric power source coupled to the second ends of the third lead and the fourth lead, supplying an electric current to the second bridge wire on demand.
15. A flat electric match as claimed in claim 14 further including a third bridge wire electrical coupled to and extending between the first electrical lead and the second electrical lead, spaced from the bridge wire, and contacting at least a portion of the pyrotechnic material, and a fourth bridge wire electrical coupled to and extending between the third electrical lead and the fourth electrical lead spaced from the second bridge wire, and contacting at least a portion of the second pyrotechnic material.
16. A flat electric match as claimed in claim 9 further comprising:
- the substrate having a second surface;
- at least one bridge wire carried by the substrate on the second surface, the at least one bridge wire electrically coupled between the first electrical lead and the second electrical lead; and
- a second pyrotechnic material carried by the substrate on the second surface, at least a portion of the second pyrotechnic material contacting the at least one bridge wire.
Type: Application
Filed: Apr 24, 2008
Publication Date: Oct 29, 2009
Inventors: Joseph M. Rustick (Phoenix, AZ), Michael K. Levenson (Tempe, AZ)
Application Number: 12/108,831
International Classification: F42B 3/10 (20060101);