Patent Grant
8286555
Not applicable.
Not applicable.
High explosives and exploding devices are employed in a wide variety of commercial applications, for example, in mining, in hydrocarbon production, in building demolition, and in other applications. A high explosive may be categorized as either a primary explosive or a secondary explosive. Primary explosives are highly sensitive to stimuli such as impact, friction, heat, and/or electrostatic charges; secondary explosives are less sensitive to stimuli. Those skilled in the art often use the sensitivity of PETN (Pentaerythritol Tetranitrate) explosive as a benchmark. Primary explosives may be identified as explosives that are more sensitive than PETN, and secondary explosives may be identified as explosives that are less sensitive than PETN. Explosives may be additionally characterized by a variety of different parameters including sensitivity to impact, thermal stability, ability to dent a standard metal plate when detonated, crystal size, shape, and other parameters.
Explosives may take a variety of forms including liquids, gels, plastics, and powders. Explosive powders may be compressed to form dense pellets and/or shaped explosive charges. Explosives may comprise percentages of other non-explosive materials, for example, sawdust, powdered silica, diatomaceous earth, plastics, polymers, waxes, and other non-explosive materials. These additional non-explosive materials may contribute to stabilizing an otherwise overly sensitive explosive. The additional non-explosive materials may bind an explosive compound and promote ease of shaping a quantity of the explosive.
High explosives may be said to exhibit two modes of activity—a deflagration mode and a detonation mode. Deflagration may be referred to as a high reaction rate combustion, although the rate is subsonic compared to the speed of sound in the explosive. Detonation may be referred to as a very high reaction rate explosion. During detonation, the reaction propagates through the explosive material in excess of the speed of sound of the subject explosive material. Primary explosives generally may transition substantially immediately to detonation mode upon activation, that is, they have very short run-up distances to detonation. Secondary explosives may first activate in the deflagration mode and may later transition to the detonation mode. In secondary explosives, the run-up distance to detonation is generally longer than for primary explosives.
Commercial applications of high explosives are subject to many regulations and practical constraints. Some high explosives may be subject to United States export restrictions that forbid or limit those nations to which a device employing the high explosive may be shipped. Some high explosives may be subject to United States Department of Transportation (DOT) regulations that forbid or limit the transportation of devices employing the high explosive over public roadways, over public waterways, and/or via common carrier commercial airline flights. Businesses that use high explosives may be constrained by their commercial insurance policies and by the advice of legal counsel with reference to managing liabilities. Not least, prudent considerations for providing safe working conditions constrains the manner of using high explosives and the design of devices incorporating high explosives.
In an embodiment, a detonator assembly is disclosed. The detonator assembly comprises a deflagration to detonation transition body, a first thermally stable secondary explosive contained by the body, and a bulkhead coupled to the deflagration to detonation transition body. The bulkhead contains pressure within the body associated with firing the detonator assembly at least until a transition from a deflagration operation mode of the detonator assembly to a detonation operation mode of the detonator assembly has occurred. The detonator assembly comprises effectively no primary explosive.
In another embodiment, a composition of explosives is disclosed. The composition of explosives comprises a first layer comprising a first thermally stable secondary explosive that is less sensitive than PETN explosive. The composition of explosives further comprises a second layer comprising the first thermally stable secondary explosive and a second thermally stable secondary explosive that is less sensitive than PETN explosive. The first explosive is more sensitive than the second explosive. The first explosive and the second explosive are mixed. The second layer contains effectively no primary explosive. The composition of explosives further comprises a third layer of the second explosive packed and unmixed. The second layer is disposed between the first layer and the third layer, the first layer is in intimate contact with the second layer, and the second layer is in intimate contact with the third layer.
In an embodiment, a detonator is provided. The detonator comprises a deflagration to detonation transition body and an initiator coupled to a first opening of the body. The detonator further comprises a first thermally stable secondary explosive and a second thermally stable secondary explosive, wherein the first and second thermally stable secondary explosives are mixed and contained within the body. The detonator further comprises a booster assembly coupled to a second opening of the body, wherein the booster assembly comprises a packed thermally stable secondary explosive, and a bulkhead to retain the initiator assembly coupled to the first opening at least until a transition of the mixture of first and second thermally stable secondary explosives to detonation occurs during firing of the detonator. The detonator comprises effectively no primary explosive.
These and other features will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings and claims.
For a more complete understanding of the present disclosure, reference is now made to the following brief description, taken in connection with the accompanying drawings and detailed description, wherein like reference numerals represent like parts.
It should be understood at the outset that although illustrative implementations of one or more embodiments are illustrated below, the disclosed systems and methods may be implemented using any number of techniques, whether currently known or in existence. The disclosure should in no way be limited to the illustrative implementations, drawings, and techniques illustrated below, but may be modified within the scope of the appended claims along with their full scope of equivalents.
The present disclosure teaches a detonator suitable for use in high temperature applications, as well as in other applications, that does not employ primary explosives. For example, and without limitation, the detonator may be employed to detonate a detonating cord to fire a perforation gun as part of wellbore completion operations directed to producing hydrocarbons from a subterranean formation. In some oilfield provinces, downhole temperatures of production zones may exceed 400 degrees Fahrenheit (F.). Some oilfield provinces are located in nations that are subject to United States export restrictions that constrain the export of detonators that use primary explosives. In an embodiment, a novel explosive composition taught by the present disclosure may be employed in the detonator taught by the present disclosure. Those skilled in the art will appreciate that the detonator and the explosive composition taught by the present disclosure may be advantageously employed in a wide range of applications, not just in the exemplary embodiment of an oilfield downhole detonator and not just in high temperature applications. For example, while the detonator taught by the present disclosure may be operated in some high temperature applications where other detonators may not be suitable, the detonator of the present disclosure may also be used successfully in lower temperature environments.
In an embodiment, the detonator is of a deflagration to detonation transition (DDT) detonator type. A DDT detonator comprises a pressure containment body that may contain an explosive and an initiator. The initiator activates the explosive in the deflagration mode. As the explosive combusts, and the flame front in the explosive propagates, pressure and temperature increases within the pressure containment body, increasing the stimulus to the explosive until the explosive transitions from the deflagration mode to the detonation mode. While the flame front propagation and the transition from deflagration to detonation occur rapidly in general purpose secondary explosives, in thermally stable secondary explosives the transition from deflagration to detonation may occur relatively more slowly.
For purposes of the present disclosure, the term thermally stable secondary explosive refers to a family of secondary explosives that exhibit thermal stability when maintained at a temperature of at least 400 degrees F. for a time duration of at least one hour. Thermal stability means that the explosive does not spontaneously go active at the subject temperature and that the explosive substantially retains its key explosive characteristics at the subject temperature, for example, its characteristic sensitivity and its characteristic energy yield. Included in this family are explosives such as, but not limited to, HNS, PYX, Tacot, ONT, BRX, DODECA, and NONA. The inventors have discovered that incorporating a modified bulkhead that is designed to provide containment for the initiator during the deflagration mode of operation to maintain pressure within the interior chamber of a DDT detonator for use with thermally stable secondary explosives and to avoid the initiator being blown out the back of the interior chamber, thus reducing pressure in the interior chamber, at least until the reaction has transitioned to the detonation mode, provides an improvement over previous designs for DDT detonators. Some thermally stable secondary explosives may exhibit thermal stability at about 425 degrees F. for over 100 hours, for example, for about 200 hours. Some thermally stable secondary explosives may exhibit thermal stability at about 450 degrees F. for at least an hour. Each of these examples of thermally stable secondary explosives are comprehended by the above definition of a thermally stable explosive, where the subject explosive retains its key explosive characteristics when maintained at a temperature of at least 400 degrees F. for a time duration of at least one hour.
In some contexts, the DDT detonator taught by the present disclosure may be referred to as a thermally stable DDT detonator. Alternatively, in some contexts the DDT detonator taught by the present disclosure may be referred to as a high temperature DDT detonator. It is understood, however, that the DDT detonator taught by the present disclosure—whether referred to as a thermally stable DDT detonator or as a high temperature DDT detonator—is not limited to being used in high temperature environments and is not limited to being used in applications that require the use of a thermally stable detonator.
In some embodiments of the thermally stable DDT detonator, the thermally stable secondary explosive comprises a mixture of a first thermally stable secondary explosive and a second thermally stable secondary explosive, where the first thermally stable secondary explosive is more sensitive than the second thermally stable secondary explosive, but in another embodiment of the thermally stable DDT detonator, the thermally stable secondary explosive may comprise the first thermally stable secondary explosive substantially unmixed. In some embodiments of the thermally stable DDT detonator, a layer of the first thermally stable secondary explosive unmixed with other explosive material is disposed between the initiator and the mixture of the first and second thermally stable secondary explosives. In an embodiment of the thermally stable DDT detonator, the first thermally stable secondary explosive may comprise at least 10% of the explosive material in the mixture of the first and second thermally stable secondary explosives. In another embodiment of the thermally stable DDT detonator, the first thermally stable secondary explosive may comprise at least 40% of the explosive material in the mixture of the first and second thermally stable secondary explosives. In another embodiment of the thermally stable DDT detonator, the first thermally stable secondary explosive may comprise at least 65% of the explosive material in the mixture of the first and second thermally stable secondary explosives. In another embodiment of the thermally stable DDT detonator, the first thermally stable secondary explosive may comprise between about 75% and 95% of the explosive material in the mixture of the first and second thermally stable secondary explosives. In another embodiment of the thermally stable DDT detonator, the first thermally stable secondary explosive may comprise between about 80% and 90% of the explosive material in the mixture of the first and second thermally stable secondary explosives. In another embodiment of the thermally stable DDT detonator, the first thermally stable secondary explosive may comprise between about 83% and 87% of the explosive material in the mixture of the first and second thermally stable secondary explosives. In other embodiments, yet other proportions may be employed.
Additionally, the present disclosure teaches a novel explosive composition that contains effectively no primary explosives and is suitable for use in high temperature applications. For example, the composition may include a first layer of a first thermally stable secondary explosive having a first sensitivity, a second layer of a mixture of the first thermally stable secondary explosive and a second thermally stable secondary explosive having a second sensitivity, where the first sensitivity is greater than the second sensitivity, and a packed third layer of the second thermally stable secondary explosive. Without limitation, in an embodiment, the first thermally stable explosive may be related to NONA and the second thermally stable secondary explosive may be related to HNS.
Turning now to
In an embodiment, the first thermally stable secondary explosive 14 and the packed thermally stable secondary explosive 18 may be defined to exhibit thermal stability at 400 degrees F. for at least one hour and to be less sensitive than PETN (Pentaerythritol Tetranitrate) explosive. In another embodiment, the first thermally stable secondary explosive 14 and the packed thermally stable secondary explosive 18 may be defined to exhibit thermal stability at 450 degrees F. for at least one hour and to be less sensitive than PETN. In another embodiment, the thermally stable secondary explosive 14 and the packed thermally stable secondary explosive 18 may be defined to exhibit thermal stability at 425 degrees F. for at least one hundred hours and to be less sensitive than PETN. As used herein, the term sensitive and/or sensitivity refer to responsiveness of an explosive to stimulus. More specifically, the term sensitivity may refer to the readiness of the explosive to be initiated and/or exploded in response to any of an impact shock, friction, shearing force, heat, static electricity, and electrical sparks.
In an embodiment, the first thermally stable secondary explosive 14 and the packed thermally stable secondary explosive 18 may be selected from one of NONA (2,2′,2″-4,4′,4″-6,6′,6″-nonanitroterphenyl), HNS-I (where HNS is generally hexanitrostilbene), HNS-II, HNS-IV, BRX (1,3,5-trinitro-2,4,6-tripicrylbenzene), PYX (picrylaminodimitropyridine), Tacot (Tetranitrobenzotriazolo-benzotriazole), ONT (2,2′,4,4′,4″,6,6′,6″ Octanitroterpheyl), DODECA (Dodecanitro-m,m′-quatraphenyl), and CL-20 (2,4,6,8,10,12-hexanitrohexaazaisowurtzitane). Other compositions having similar chemical properties and/or explosive characteristics, particularly having similar sensitivity and temperature stability, either existing or developed in the future, could likewise be used. Other compositions having similar chemical properties and/or explosive characteristics may be said to be related to these thermally stable secondary explosives. In an embodiment, the packed thermally stable secondary explosive 18 may be the same explosive as the first thermally stable secondary explosive 14.
In an embodiment, during assembly of the first thermally stable DDT detonator 10, the first thermally stable secondary explosive 14 may be introduced into an interior chamber of the first DDT body 12 in small increments. Between the introductions of small increments of the first thermally stable secondary explosive 14, the first DDT body 12 may be vibrated to promote the elimination of excess air between the particles of the first thermally stable secondary explosive 14. In some contexts, the packed thermally stable secondary explosive 18 may be referred to as a pellet of thermally stable secondary explosive. In an embodiment, the first thermally stable secondary explosive 14 and the packed thermally stable secondary explosive 18 may contain a small portion of non-explosive materials, for example, but not by way of limitation, polymers, waxes, or binders, to promote stability, handling, and/or shaping characteristics.
The cup 17 may be formed of any material suitable to retain the packed thermally stable secondary explosive 18 and to propagate detonation, for example, to propagate detonation to a detonating cord associated with a perforation gun. In an embodiment, the cup 17 may be formed of a thin metal material and be coupled to a nipple of the first DDT body 12, for example, by crimping the cup 17 onto the nipple. In other embodiments, however, the cup 17 may be formed of ceramic, plastic, threads, cloth, fiberglass, composite materials, or other non-metallic materials and/or coupled to the first DDT body 12 by other known retaining mechanisms, such as, but not limited to, by an adhesive, a rivet, a clip, a screw, a bolt, a pin, a weld, or a laser weld. In an embodiment, the cup 17 may be coupled to the first DDT body 12 by a snap fit. In an embodiment, the interior of the cup 17 may have surface irregularities, for example, ridges, stippling, and/or other surface irregularities, to promote adherence of the packed thermally stable secondary explosive 18 in the cup 17. In an embodiment, the cup 17 may have a variety of shapes and sizes and is not limited by the proportions represented in
The first DDT body 12 may be formed of any high strength material suitable for substantially retaining the pressure generated by activation of the first thermally stable secondary explosive 14, at least until the reaction transitions to the detonation mode. In an embodiment the first DDT body 12 may be formed of a metal, such as, but not by way of limitation, steel, or a non-metal, such as, but not by way of limitation, ceramic, plastic, reinforced composite materials, or another high strength material. The first DDT body 12 defines the interior chamber that contains the first thermally stable secondary explosive 14 and the initiator 20. It is understood that
The initiator 20 generates a hot flame front to initiate deflagration of the first thermally stable secondary explosive 14. The initiator 20 may activate in response to external signals, including a pressure signal, an electrical signal, and/or another type of signal. For example, the initiator 20 may activate in response to a percussive impulse, for example, an impact from a firing pin. As an alternative example, the initiator 20 may activate in response to an electrical current, for example, but not by way of limitation, in response to a surge of current from a charged electrical capacitor. In an embodiment, the initiator 20 may comprise one of a semiconductor bridge (SCB), a primer, and a percussion cap. In an embodiment, the initiator 20 further comprises an energetic material, such as an insensitive pyrotechnic material, in intimate contact with the first thermally stable secondary explosive 14. As used herein, the term pyrotechnic refers to a material which burns but does not detonate. In an embodiment, the pyrotechnic material may comprise THKP (titanium hydride potassium perchlorate) pyrotechnic powder, TSPP (titanium subhydride potassium perchlorate) pyrotechnic material, TMAP-KP (tetramethylammonium perchlorate-potassium perchlorate) pyrotechnic material, or another pyrotechnic material. Each of these pyrotechnic materials are known to burn at a very high temperature, which is suitable for reliably initiating the deflagration of the first thermally stable secondary explosive 14.
The bulkhead 22 is coupled to the first DDT body 12 to confine and enhance pressure build-up during the deflagration to detonation transition. In some contexts the bulkhead 22 may be referred to as a plug or a cap. In an embodiment, the bulkhead 22 may be coupled to the first DDT body 12 by one of screws, bolts, rivets, adhesives, a locking ring, an interference fit, a snap fit, pins, and other like attaching hardware. In an embodiment, the bulkhead 22 may be coupled to the first DDT body 12 by threaded engagement between a threading of the bulkhead 22 and a thread of the first DDT body 12. In an embodiment, the bulkhead 22 may be coupled to the first DDT body 12 by welding and/or spot welding. In an embodiment, the bulkhead 22 may be coupled to the first DDT body 12 by fusing together some of the material of the bulkhead 22 with some of the material of the first DDT body 12, for example, using a laser welder and/or an ultrasound process.
In an embodiment, once the transition to detonation has occurred, the bulkhead 22 need no longer remain coupled to the first DDT body 12, because once detonation has been achieved in the first thermally stable secondary explosive 14 the detonation may continue to propagate independently of the bulkhead 22 confining and enhancing pressure build-up. Thus, in an embodiment, the bulkhead 22 may rupture or the coupling of the bulkhead 22 to the first DDT body 12 may fail after detonation of the first thermally stable secondary explosive 14 is achieved. In an embodiment, the bulkhead 22 and the coupling of the bulkhead 22 to the first DDT body 12 are designed to contain pressure substantially within the interior chamber after activation of the first thermally stable secondary explosive 14 and until the deflagration to detonation transition occurs. In an embodiment, the bulkhead 22 and the coupling are designed to contain pressure substantially within the interior chamber for at least 0.5 microsecond (500 nanoseconds) after activation of the first thermally stable secondary explosive 14. In an embodiment, the bulkhead 22 and the coupling are designed to contain pressure substantially within the interior chamber for at least 1 microsecond after activation of the first thermally stable secondary explosive 14. In an embodiment, the bulkhead 22 and the coupling are designed to contain pressure substantially within the interior chamber for at least 10 microseconds after activation of the first thermally stable secondary explosive 14. In an embodiment, the bulkhead 22 and the coupling are designed to contain pressure substantially within the interior chamber for at least 100 microseconds after activation of the first thermally stable secondary explosive 14. In an embodiment, the bulkhead 22 and the coupling are designed to contain pressure substantially within the interior chamber for at least 1 millisecond after activation of the first thermally stable secondary explosive 14. In an embodiment, the bulkhead 22 and the coupling are designed to withstand a pressure of at least 50 pounds per square inch (PSI) applied to the bulkhead 22. In an embodiment, the bulkhead 22 and the coupling are designed to withstand a pressure of at least 100 PSI applied to the bulkhead 22. In an embodiment, the bulkhead 22 and the coupling are designed to withstand a pressure of at least 200 PSI applied to the bulkhead 22. In an embodiment, the bulkhead 22 and the coupling are designed to withstand a pressure of at least 500 PSI applied to the bulkhead 22. In an embodiment, the bulkhead 22 and the coupling are designed to withstand a pressure of at least 1000 PSI applied to the bulkhead 22. In an embodiment, the bulkhead 22 and the coupling are designed to withstand a pressure of at least 5000 PSI applied to the bulkhead 22. In an embodiment, the bulkhead 22 and the coupling are designed to withstand a pressure of at least 10000 PSI applied to the bulkhead 22.
Turning now to
In an embodiment, during assembly of the second thermally stable DDT detonator 40, the mixture of explosives 42 may be introduced into the interior chamber in small increments. Between the introductions of small increments of the mixture of explosives 42, the first DDT body 12 may be vibrated to promote the elimination of excess air between the particles of the mixture of explosives 42. In an embodiment, the mixture of explosives 42 may comprise a second thermally stable secondary explosive and a third thermally stable secondary explosive. In an embodiment, the second thermally stable secondary explosive and the third thermally stable secondary explosive may be defined to exhibit thermal stability at 400 degrees F. for at least one hour and to be less sensitive than PETN explosive. In another embodiment, the second thermally stable secondary explosive and the third thermally stable secondary explosive may be defined to exhibit thermal stability at 450 degrees F. for at least one hour and to be less sensitive than PETN. In another embodiment, the second thermally stable secondary explosive and the third thermally stable secondary explosive may be defined to exhibit thermal stability at 425 degrees F. for at least one hundred hours and to be less sensitive than PETN.
In an embodiment, the second thermally stable secondary explosive may comprise from 10% to 98% of the mixture of explosives 42. In another embodiment, the second thermally stable secondary explosive may comprise from 65% to 98% of the mixture of explosives 42. In another embodiment, the second thermally stable secondary explosive may comprise from 75% to 95% of the mixture of the explosives 42. In another embodiment, the second thermally stable secondary explosive may comprise 80% to 90% of the mixture of the explosives 42. In another embodiment, the second thermally stable secondary explosive may comprise 83% to 87% of the mixture of the explosives 42. In an embodiment, the second thermally stable secondary explosive comprises NONA or an explosive related to NONA. In an embodiment, the third thermally stable secondary explosive comprises HNS-I, HNS-II and/or HNS-IV. In an embodiment, the third thermally stable secondary explosive comprises an explosive related to HNS-I, HNS-II, and/or HNS-IV.
Turning now to
Turning now to
Turning now to
Turning now to
Turning now to
Turning now to
In some contexts herein, the thermally stable DDT detonator is said to contain “effectively no primary explosives” to provide for the possibility that some minute and unintentional quantities of primary explosives may be found in the secondary explosives. Such trace amounts of primary explosives may unintentionally infiltrate the secondary explosives by a variety of circumstances, some examples of which are described following. The primary explosives may be present as an unintended impurity of the manufacturing process, the depot handling process, and/or the field handling process. For example, an inconsiderable quantity of primary explosive may infiltrate the thermally stable DDT detonator by contamination from tooling or from the ambient manufacturing environment or from handling in a depot that includes other detonator devices that contain primary explosives. Alternatively, in an embodiment, a small amount of primary explosive may be present in a quantity that is insufficient to trigger transportation and/or export regulations directed to primary explosives. For example, in an embodiment, a small quantity of primary explosive—less than the quantity that invokes application of transportation and/or export regulations related to primary explosives—may be mixed into the thermally stable secondary explosive proximate to the booster assembly 16 to assure the transition from deflagration to detonation in worst case circumstances and thereby enhance the reliability of the thermally stable DDT detonator. In yet another embodiment, a small quantity of primary explosive, for example, but not by way of limitation, such as lead azide and/or silver azide, may be present in the initiator 20. In effect, the inclusion of such small quantities of primary explosives does not substantively change the novel principle of operation and the novel structure taught by the present disclosure.
It will be appreciated by those skilled in the art that a commercial detonator ought to be reliable. A detonator design that exhibits unpredictably variable behavior is dangerous, reduces customer satisfaction, and leads to lost time and money. Several aspects of the embodiments of the DDT detonators described above address enhancing the reliability of the DDT detonators for use in high temperature environments, for example, environments where the DDT detonator may be subjected to a temperature of at least 400 degrees F. for at least 1 hour.
Turning now to
In an embodiment, the composition 100 may be employed in combination with the thermally stable DDT detonator described in more detail above. One skilled in the art, however, will appreciate that the composition 100 may have applications in other structures and apparatuses. Additionally, although depicted in
A delay element may be introduced into any of the embodiments of the thermally stable DDT detonator described above. In embodiments having a delay element, an initiator and/or a pyrotechnic initiates a burning reaction in a delay column formed of a combustible material, such as, but not by way of limitation, a compacted tungsten powder or a tungsten powder mixture. In some contexts this delay column may be referred to as a fuse or as providing functionality similar to that of a fuse. The delay column burns, effecting a delay, until it reaches the secondary explosive mixture which then initiates and begins the deflagration to detonation reaction, as described above.
Turning now to
Turning now to
Turning now to
It will be appreciated that the fourth DDT body 132 may be combined with other embodiments and configurations of thermally stable DDT detonators described above. For example, in an embodiment, the mixture of explosives 42 contained in the tenth thermally stable DDT detonator 130 and/or in the eleventh thermally stable DDT detonator 136 may be replaced with the first thermally stable secondary explosive 14 of the first thermally stable DDT detonator 10. In an embodiment, the tapered interior chamber of the DDT body described in the third thermally stable DDT detonator 50 and/or the fourth thermally stable DDT detonator 60 may be combined with the tenth thermally stable DDT detonator 130 and/or in the eleventh thermally stable DDT detonator 136. Likewise, the tenth thermally stable DDT detonator 130 and/or the eleventh thermally stable DDT detonator 136 may comprise a layer of the unmixed second thermally stable secondary explosive 72 disposed between the initiator 20 and the mixture of explosives 42. Likewise, in an embodiment, the subassembly 82 described above with reference to
Turning now to
While various ratios of NONA secondary explosive mixed with HNS secondary explosive may be effective in the thermally stable DDT detonator, the graph in
While several embodiments have been provided in the present disclosure, it should be understood that the disclosed systems and methods may be embodied in many other specific forms without departing from the spirit or scope of the present disclosure. Additionally, one skilled in the art will readily appreciate that many of the distinctive features of the several described embodiments may advantageously be recombined in derivative embodiments that are equally contemplated by the present disclosure. The present examples are to be considered as illustrative and not restrictive, and the intention is not to be limited to the details given herein. For example, the various elements or components may be combined or integrated in another system or certain features may be omitted or not implemented.
Also, techniques, systems, subsystems, and methods described and illustrated in the various embodiments as discrete or separate may be combined or integrated with other systems, modules, techniques, or methods without departing from the scope of the present disclosure. Other items shown or discussed as directly coupled or communicating with each other may be indirectly coupled or communicating through some interface, device, or intermediate component, whether electrically, mechanically, or otherwise. Other examples of changes, substitutions, and alterations are ascertainable by one skilled in the art and could be made without departing from the spirit and scope disclosed herein.
This application is a divisional of and claims priority under 35 U.S.C. §120 to U.S. patent application Ser. No. 12/643,988, filed Dec. 21, 2009, entitled “Deflagration to Detonation Transition Device,” by Thomas J. Wuensche, et al., which is incorporated herein by reference for all purposes. This application is also related to U.S. patent application Ser. No. 13/356,625, filed Jan. 23, 2012, entitled “Deflagration to Detonation Transition Device,” by Thomas J. Wuensche, et al., which is a continuation of U.S. patent application Ser. No. 12/643,988, filed Dec. 21, 2009, entitled “Deflagration to Detonation Transition Device,” by Thomas J. Wuensche, et al., both of which are incorporated herein by reference in their entirety.
| Number | Name | Date | Kind |
|---|---|---|---|
| 4735145 | Johnson et al. | Apr 1988 | A |
| 4759291 | Barker et al. | Jul 1988 | A |
| 4777878 | Johnson et al. | Oct 1988 | A |
| 4920883 | Barker | May 1990 | A |
| 4998477 | Barker | Mar 1991 | A |
| 5889228 | Ewick et al. | Mar 1999 | A |
| 6053111 | Motley | Apr 2000 | A |
| 6408759 | Ewick et al. | Jun 2002 | B1 |
| 6435095 | Menzel et al. | Aug 2002 | B1 |
| 6467415 | Menzel et al. | Oct 2002 | B2 |
| 7343860 | Michel et al. | Mar 2008 | B2 |
| 7661362 | Hennings et al. | Feb 2010 | B2 |
| 7987787 | Sudick | Aug 2011 | B1 |
| 8042471 | Michel et al. | Oct 2011 | B2 |
| 8161880 | Wuensche et al. | Apr 2012 | B2 |
| 20020088363 | Menzel et al. | Jul 2002 | A1 |
| 20080011179 | Michel et al. | Jan 2008 | A1 |
| 20100031841 | Michel et al. | Feb 2010 | A1 |
| 20100180786 | Goodridge et al. | Jul 2010 | A1 |
| 20110146517 | Wuensche et al. | Jun 2011 | A1 |
| Number | Date | Country | |
|---|---|---|---|
| 20120118447 A1 | May 2012 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 12643988 | Dec 2009 | US |
| Child | 13356619 | US |
