Patent Application
20120192748
The present disclosure relates generally to coupling adapters for securing together different sized components and, more particularly, to a coupling adapter configured to provide for the direct insertion of various detonators and/or blasting caps into explosive charges.
Conventional military and commercial demolition systems typically require a variety of explosive detonators and/or blasting caps to insure their proper operation. These detonators and/or blasting caps are produced in various lengths and diameters and may have different input leads depending upon their particular nature (electric, non-electric, exploding bridgewire detonator, etc.). A typical detonator well consists of a cylindrical, threaded hole protruding into the explosive device. The appropriate detonator and/or cap is then inserted into the detonator well, which typically requires a specialized adapter that accounts for the individual detonator design and serves to secure the detonator to the charge.
As such, a potential exists that for every unique detonator there is a specialized adapter required for its use. This often causes difficulty in field use and logistics support because of the need to recognize and insure the availability of the appropriate adapter as needed. Conventional specialized adapters are typically threaded parts requiring careful installation by the user into the accepting detonator well. This is often a dangerous and time consuming process.
As such, there is a need for a system to reduce and/or eliminate the amount of specialized accessories necessary to adapt different sized detonators to explosive charges. Such reduction or elimination of specialized adapters saves the user time, weight, and space, while also reducing the risk to the system caused by lost and/or omitted parts.
According to an illustrative embodiment of the present disclosure, a coupling adapter includes a side wall having an inner surface, a plurality of circumferentially spaced retaining fins supported by the side wall, wherein each of the retaining fins extends radially inwardly from an outer end coupled to the inner surface of the side wall to an inner end. The coupler adapter further includes a receiving bore defined by the inner ends of the retaining fins, wherein the receiving bores extend axially between a first end and a second end and are configured to receive an elongated member. Each of the retaining fins is flexible for bending movement in tangential and radially outward directions to retain elongated members of varying lateral dimensions slidably received within the receiving bore.
According to another illustrative embodiment of the present disclosure, a coupling adapter includes a side wall and a plurality of circumferentially spaced retaining fins supported by the side wall. Each of the retaining fins extends radially inwardly from an outer end coupled to the inner surface of the side wall to an inner end, wherein each of the retaining fins is flexible such that the inner end is supported to move relative to the outer end. A receiving bore is defined by the retaining fins and is configured to receive an elongated member. The receiving bore includes a first diameter defined by the retaining fins when in a relaxed mode, a second diameter defined by the retaining fins when in a first expanded mode, and a third diameter defined by the retaining fins when in a second expanded mode. The second diameter is greater than the first diameter, and the third diameter is greater than the second diameter.
According to a further illustrative embodiment of the present disclosure, a detonator assembly for an explosive charge includes a housing configured to receive an explosive charge, a holder coupled to the housing, and a coupling adapter coupled to the holder and including a side wall. The coupling adapter includes a plurality of retaining fins extending inwardly from the side wall, and a receiving bore defined by the retaining fins and having a variable cross-section defined by the retaining fins. A detonator is received within the receiving bore, and bends the inner edges of the fins outwardly to adjust the cross-section of the receiving bore and provide an interference fit between the detonator and the retaining fins.
According to another illustrative embodiment of the present disclosure, a method of coupling includes the steps of providing a coupling adapter including a sidewall and a plurality of inwardly extending retaining fins, the retaining fins defining a receiving bore, slidably inserting an elongated member within the receiving bore of the coupling adapter, bending the retaining fins outwardly to increase the cross-section of the retaining bore, and retaining the elongated member through an interference fit with the retaining fins.
The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same become better understood by reference to the following detailed description when taken in conjunction with the accompanying drawings.
Corresponding reference characters indicate corresponding parts throughout the several views. Although the drawings represent embodiments of various features and components according to the present disclosure, the drawings are not necessarily to scale and certain features may be exaggerated in order to better illustrate and explain the present disclosure. The exemplification set out herein illustrates embodiments of the invention, and such exemplifications are not to be construed as limiting the scope of the invention in any manner.
For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings, which are described below. The embodiments disclosed below are not intended to be exhaustive or limit the invention to the precise form disclosed in the following detailed description. Rather, the embodiments are chosen and described so that others skilled in the art may utilize their teachings. It will be understood that no limitation of the scope of the invention is thereby intended. The invention includes any alterations and further modifications in the illustrated devices and described methods and further applications of the principles of the invention which would normally occur to one skilled in the art to which the invention relates.
Referring initially to
The housing 12 illustratively includes a cylindrical base member or canister 16 and a cover or lid 18 operably coupled thereto. The cover 18 may be secured to the canister 16 though conventional means, such as fasteners, adhesives, or cooperating threads. The cover 18 includes a central bore 20 having internal threads 22. A holder 24 including external threads 25 is configured to be received within the bore 20 and threadably couple with internal threads 22 of the cover 18. A coupling adapter or receptacle 30 is operably coupled to the cover 18 by the holder 24 and is configured to slidably receive a detonator 26, sometimes referred to as a “blasting cap.”
Detonator 26 includes a casing 32 containing a relatively sensitive, primary explosive material (not shown), which is less stable, and therefore easier to ignite, than the secondary explosive material 14 contained in canister 16. Because detonator 26 may easily ignite, detonators 26 are typically stored apart from explosive device 10.
The types of detonators 26 used with explosive device 10 may vary. Suitable detonators 26 may include, for example, non-electric caps, electric caps which are triggered by an electric current, and fuse caps which are triggered with a heat source. Detonators 26 may include instantaneous electric blasting caps, instantaneous non-electric blasting caps, HERO safe electric blasting caps, exploding bridge wire (EBW), detonators, and non-electric delay blasting caps and detonators. For example, illustrative detonators 26 may include M7 non-electric detonators, M6 electric blasting caps, and MK17 electric blasting caps having outer diameters of approximately 0.24 inches and available from a variety of sources. Illustrative detonators 26 may also include RP-83 EBW detonators having outer diameters of approximately 0.272 inches and available from RISI of Tracy, Calif., and non-electric delay detonators having outer diameters of approximately 0.295 inches and available from various sources.
The primary explosive material contained in the casing 32 of detonator 26 may also vary. Suitable primary explosive materials for use in detonator 26 includes, for example, pentaerythritol tetranitrate (PETN), cyclotrimethylenetrinitramine (RDX), mercury fulminate, lead azide, lead styphnate, tetryl, and diazodinitrophenol (DDNP).
The illustrative detonator 26 may be operably coupled to a transmission line, illustratively a non-electric transmission line 34. Transmission line 34 may be provided in the form of a “detonating cord” or “detcord.” Transmission line 34 may also be provided in the form of a “shock tube.” In the detcord embodiment, transmission line 34 may include a flexible, hollow tube that contains a secondary explosive material (not shown). The secondary explosive material in the transmission line 34 may convey or transmit an explosive charge from an input end 36 to an output end 38 coupled to the detonator 26, allowing transmission lines 34 to act as high-speed fuses.
The type and quantity of the secondary explosive material contained in transmission line 34 may vary. In the case of a detcord, a suitable secondary explosive material for use in transmission line 34 includes, for example, pentaerythritol tetranitrate (PETN). In the case of a shocktube, a suitable secondary explosive material for use in transmission lines 34 includes, for example, a mixture of cyclotetramethylene-tetranitramine (HMX) and aluminum. Also, transmission line 34 may contain 5 grains of explosive per foot, for example, although it is also within the scope of the present disclosure that transmission line 34 may contain 0.1 grains of explosive per foot, 2.5 grains of explosive per foot, 7.5 grains of explosive per foot, or 10 grains of explosive per foot, or 50 grains of explosive per foot, for example.
With reference now to
Each of the retaining fins 46 is flexible for bending movement or flexion in both tangential and radially outward directions in order to retain elongated coupled members of varying lateral dimensions and cross-sectional shapes, illustratively detonators 26 of various sizes and shapes, slidably received within the receiving bore 54. More particularly, the inner ends 50 are movable relative to the outer ends 48 of retaining fins 46 in order to change the cross-sectional size and/or shape of the receiving bore 54. The receiving bore 54 includes a first diameter (id1) defined by the retaining fins 46 when in a relaxed mode as shown in
With further reference to
With further reference to
A first end 60 of the receiving bore 54 illustratively includes a frusto-conical entry 62 defined by tapered upper portions 64 of the fins 46. The frusto-conical entry 62 may be eliminated, particularly in coupling adapters 30 having short lengths. A securing lip 66 extends radially outwardly from the side wall 40 proximate the second end 68 of the receiving bore 54. The securing lip 66 illustratively facilitates coupling between the holder 24 and the cover 18 of the explosive device 10. More particularly, the securing lip 66 is received within a counterbore 70 of the holder 24 to prevent unwanted removal of coupling adapter 30 upwardly through the holder 24 of
During assembly coupling adapter 30 is slidably inserted into the holder 24 until the securing lip 66 is received within the counterbore 70. Next, the cover 18 is secured to the canister 16 which has been filled with secondary explosive material 14. The holder 24 is then threadably received within bore 20 of cover 18 until properly positioned relative to an upper surface 72 of the secondary explosive material 14. The detonator 26 is next slidably inserted within the receiving bore 54 of the coupling adapter 30 until it abuts the upper surface 72 of the secondary explosive material 14. The inner ends 50 of retaining fins 46 bend outwardly to increase the cross-section of the receiving bore 54 wherein the casing 32 of detonator 26 is retained through an interference fit with the retaining fins 46. As such, the receiving bore 54 is self adjusting to accommodate the size and shape of detonator 26.
The coupling adapter 30 enables the housing 12 to hold detonators 26 of varying shapes and sizes. The flexible fins 46 extend inward to grab small diameter detonators or blasting caps 26a, but also give enough flexibility to accept the insertion of larger diameter detonators 26b. The flexibility of the fins 46 allows the effective internal diameter (id) of the receiving bore 54 to expand without causing an undue increase in the amount of force required to insert large diameter detonators 26b. In other words, the coupling adapter 30 provides variable diameter interference fit without requiring a “force fit.”
While the above description details use of the coupling adapter 30 in connection with detonators 26 and explosive devices 10, both military and commercial, the invention may find use with any application requiring the coupling of components of varying shapes and sizes. For example, the coupling adapter 30 may be used to provide a secure interference fit between shafts of varying diameters without causing an undo force fit or requiring specialized adapters. Any application requiring the coupling of otherwise imprecisely fitting shafts of a wide variety of shapes and sizes could benefit from the coupling adapter 30. Alternatively, the coupling adapter 30 could be adapted to rotating machinery by coupling together of inexact fitting rotating shafts.
While this invention has been described as having an exemplary design, the present invention may be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains.
This application claims priority to U.S. Provisional Patent Application Ser. No. 61/438,793, filed Feb. 2, 2011, the disclosure of which is expressly incorporated by reference herein.
The invention described herein includes contributions by one or more employees of the Department of the Navy made in performance of official duties and may be manufactured, used and licensed by or for the United States Government for any governmental purpose without payment of any royalties thereon.
| Number | Date | Country | |
|---|---|---|---|
| 61438793 | Feb 2011 | US |
