US 3678853 A
Apparatus for transferring a shock wave front from one detonating cord to another including quick-disconnect end connectors adapted to provide the respective ends of the cords with a quick-disconnect capability and a central interconnector having quick-disconnect mating end portions. Each detonating cord is attached to its respective end of the interconnector which itself might extend through an intervening obstruction. The central interconnector includes a cylindrical housing enclosing an explosive transfer lead composed of hexanitrostilbene explosive.
Description (OCR text may contain errors)
United States Patent Kilmer [451 July 25,1972
QUICK DISCONNECT EXPLOSIVE CONNECTOR ASSEMBLY Inventor: Earl E. Kilmer, College Park, Md.
Assignee: The United States of America as represented by the Secretary of the Navy Filed: June 12, 1970 Appl. No.: 57,848
U.S. Cl. ..l02/27 R, 102/70 R ..F42b 3/10 Field of Search 102/27, 28, 70
References Cited UNITED STATES PATENTS 3,129,663 4/1964 Schnepfe, Jr. 102/27 Godchaux et al 102/27 3,209,692 10/1965 Webb 102/27 X 3,326,127 6/1967 Schimmel. 3,238,876 3/1966 Allen 102/27 X Primary Examiner-Samuel W. Engle Alrorney-R. S. Sciascia and J. A. Cooke  ABSTRACT Apparatus for transferring a shock wave front from one detonating cord to another including quick-disconnect end connectors adapted to provide the respective ends of the cords with a quick-disconnect capability and a central interconnector having quick-disconnect mating end portions. Each detonating cord is attached to its respective end of the interconnector which itself might extend through an intervening obstruction. The central interconnector includes a cylindrical housing enclosing an explosive transfer lead composed of hexanitrostilbene explosive.
4 Claims, 4 Drawing Figures Patenied July 25, 1972 3,678,853
2 Sheets-Sheet 2 QUICK DISCONNECT EXPLOSIVE CONNECTOR ASSEMBLY BACKGROUND OF THE INVENTION The present invention relates in general to explosive connector assemblies and more particularly to a quick-disconnect explosive connector assembly for detonating cords which enables a shock wave to be transmitted through an obstruction.
In the past, conventional mild detonating cord, hereinafter referred to as MDC, using standard explosives, such for example, as PETN, was employed to detonate conventional booster charges by means of the transmission of a low intensity detonation front. Advances in technology necessitated the development of a heat resistant MDC in order to withstand the extreme temperatures developed in various rocket and missile applications. The heat resistant MDC was packed with a heat resistant explosive having such characteristics as a melting point above 300 C and a vacuum thermal stability such that it decomposes at a rate less than 2.0 cc/gram/hr at 260 C. Since the shock detonation front produced by the heat resistant MDC was substantially smaller than the front created using the above discussed conventional MDC, various problems arose. For example, to initiate standard booster charges a device for amplifying and intensifying the detonation front produced by the heat resistant MDC was required. Such a device is disclosed in application Ser. No. 475,035, filed by E. E. Kilmer on July 26, 1965. Other applications requiring the use of heat resistant MDC posed further problems such as the transfer of the detonation front from one cord to another, particularly when an obstruction, such for examples as a bulkhead, was interposed in the path of the shock front. Additionally, the connection of the end of MDC to an explosive charge often posed serious problems when such charge was positioned in a relatively confined and inaccessible location. Previously, when such connection was necessary a time consuming and complicated process was required to affect a positive coupling and oftentimes it was found that even after such process was completed a sufiicient connection had not been accomplished.
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a new and improved explosive connector assembly.
Another object of this invention is to provide a new quickdisconnect explosive connector assembly enabling a facil connection between corresponding parts.
A further object of the instant invention is to provide a quick-disconnect explosive connector assembly which accomplishes the transfer of a travelling shock front through an obstruction.
Briefly, these and other objects are obtained by providing the ends of two mild detonating cords with quick-disconnect end connectors and attaching each cord to an end of an elongated central interconnector adapted to receive the end connectors and to extend through an obstruction.
BRIEF DESCRIPTION OF THE DRAWING A more complete appreciation of the invention and many of the attendant advantages thereof will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:
FIG. 1 is a side sectional view of an end connector adapted to be fitted on the mild detonating cord of FIG. 2;
FIG. 2 is a side view, partially in section, of mild detonating cord having associated therewith a quick-disconnect end connector adapter;
FIG. 3 is a longitudinal sectional view of the central interconnector of the explosive connector assembly; and
FIG. 4 is a longitudinal view, partly in section, of the quickdisconnect explosive connector assembly.
DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawing wherein like reference characters designate identical or corresponding parts throughout the several views and more particularly to FIG. I, the end connector 10 of the assembly is shown as including a partially internally threaded cylindrical inner member I2, a cylindrical collar 14 slidably positioned around and substantially enclosing the inner member 12, a cylindrical Teflon (polytetrafluoroethylene) liner 16 formed on one of the bores in inner member I2 and a ring member 18 formed of a resilient material, such for example as rubber, held in place by the abutting relationship of inner member 12 and collar 14. A spring washer 19 loosely surrounds the inner member 12 and comprises a resilient metallic corrugated ring.
Inner member 12 includes an axial bore 20 on which liner 16 is positioned, a reduced diameter bore 21 cooperating with bore 20 to form annular shoulder 23 and an enlarged axial counterbore 22 opening into bore 21 thereby defining an intermediate annular shoulder 24. An internally threaded counterbore 26 cooperates with the first counterbore 22 and opens through one end of inner member 12. The outer surface of inner member 12 is of a varying diameter throughout its length and defines an annular retaining flange 28 which extends around the outer perimeter of inner member 12. Further, a tubular portion is defined having a bevelled step 34 formed thereon which provides thick and thin walled tube portions 30 and 32. Retaining flange 28 intersects the thick walled tube portion 30 to define an annular shoulder 36.
Counterbore 26 is of larger diameter than the other bores and is internally threaded to receive mating apparatus which will be discussed hereinafter. The liner 16 is formed on the surface of bore 20 and extends the entire length thereof and abuts against annular shoulder 23. As is clearly shown, the diameter of bore 21 is equal to the diameter of the bore formed in liner 16 thereby forming a continuous internal cylindrical surface.
Collar 14 has an annular flange 37 externally formed on the front portion thereof and a knurled raised portion (FIG. 4) 38 extending around the perimeter of the rear portion thereof. An axial bore 40 is formed within collar 14 of greater diameter than the outer diameter of the thick walled tube portion 30. Cooperating with bore 40 and formed within raised portion 38 is a counterbore 42 which defines an annular groove in which spring washer 19 is positioned. A retaining ring 44 is held in place by crimping the end of raised portion 38 as at 45 thus making the retaining ring 44 and collar member 14 integral. A notch 48 is formed at the intersection of axial bore 40 and shoulder 46 which serves to hold ring member 18 in place against shoulder 36 when the end connector is suitably fastened to mating apparatus as will be described in greater detail hereinafter.
The end connector 10 is assembled by first positioning ring member 18 around the thick walled tubular portion 30 in abutting relationship with shoulder 36. Collar member 14 is then slidably adapted on inner member 12 by inserting the retaining flange 28 within counterbore 42 with spring Washer 19 being positioned rearward of flange 28. Retaining ring 44 is then fixed to collar member 14 by crimping the end of raised portion 38 as discussed hereinbefore. As a result of the continuous bias produced by spring washer 19 which tends to force ring 44 and flange 28 in opposite directions, the collar member 14 will be in a position relative to inner member 12 such that shoulder 46 will abut retaining flange 28 as best seen in FIG. 1. Ring member 18 is of a thickness that when this position is effected, the ring will be compressed and rigidly held in place by notch 48 and shoulder 36.
By virtue of the diameter of bore 40 being greater than the outer diameter of thick walled tube portion 30, an annular cavity 50 is defined by the outer surface of the thick and thin walled portions 30 and 32 and the surface of bore 40. Cavity 50 is of a configuration to receive an interconnector as will be more fully described hereinafter. A helical slot 52 is formed in the wall of collar 14 as shown partially in phantom construction in FIG. 1.
The end connector is attachable to a heat resistant mild detonating cord as shown in FIG. 2. The end of the heat resistant MDC and associated apparatus is to be fitted within and fastened to the end connector 10 to thereby achieve a quick disconnect capability. The end 54 of the MDC is connected to a base charge 56 by an end coupler 58. The MDC itself is composed of a cylindrical sheath 60 which is filled with a heat resistant explosive such, for example, as DIPAM (dipicramid). The end coupler 58 includes a housing 62 having a frusto-conical recess 64 formed in the front portion thereof and a communicating axial bore 66 formed in the rear portion thereof. The recess 64 is filled with a heat resistant explosive 68 and the end 54 of the MDC is fitted within bore 66 to thereby communicate with explosive 68.
The base charge 56 is fixedly positioned adjacent the explosive filled recess 64 and is held in place by an elongate booster cup 72 whose end is attached to the end coupler 58 by means of a suitable adhesive 74 such, for example, as an epoxy resin or other potting composition which fills a beveled groove forming an annular shoulder 76. A threaded adapter 78 adapted to mate within threaded counterbore 26, having an octagonal head 80, is positioned immediately adjacent to the enlarged cylindrical portion 70 and may be formed integrally therewith.
The end connector is formed by inserting the projection defined by booster cup 72 (FIG. 2) into the threaded bore end 26 of end connector 10 and threadibly mating adapter 78 with counterbore 26 until the shoulder 76 of the enlarged cylindrical portion 70 abuts the shoulder 24 of inner member 12. The frontmost surface 82 of booster cup 72 is positioned in the same plane as that defined by the end surfaces 84 of liner l6 and thin walled portion 32 as best seen in FIG. 4. The diameter of liner 16 is of sufficient size to snugly receive the booster cup 72 while the liner insures that a smooth, non binding assembly is achieved.
The end connector described hereinbefore provides a mild detonating cord with a quick-disconnect capability which may be used to accomplish a connection with another length of MDC attached to a mating end connector. In the present embodiment a interconnector is provided each end of which is quickly connectable to the end connectors hereinbefore described.
Referring now to FIG. 3 the central interconnector 86 includes a cylindrical housing 88 having an annular lip 90 formed externally at the midpoint thereof. An explosive lead 92 is centrally positioned within housing 88 by explosive lead retaining members 94 and 96 fixedly mounted within housing 88.
The explosive lead 92 is substantially cylindrical and preferably includes three equal increments of hexanitrostilbene explosive compressed at approximately 16,000 psi. The explosive is contained in an aluminum cup 98 having an opening 100 at one end thereof wherein an aluminum closure disc 102 is positioned serving to close opening 100 and accommodate any relief bulging" of the explosive that may occur.
Retaining members 94 and 96 each have an inwardly turned lip 104 at the outer end thereof. Identical axial bores 106 are formed within each member of a size to snugly receive the explosive lead 92. The retaining member 94 has an outer diameter slightly smaller than the diameter of retaining member 96, for a reason to be discussed hereinafter, and has a reduced external end portion which defines an annular shoulder 108.
An axial bore 110 is formed within housing 88 of an appropriate diameter such that retaining member 94 will slidably fit within the bore. Axial counterbores of identical diameter and length 112 and 1 14 are formed at each end of housing 88 and define an opening continuous therethrough. The intersection of counterbores 112 and 114 defines a beveled shoulder 116 at either end of the housing 88. At one intermediate offcenter position of the housing an annular shoulder 118 is defined at the intersection of bore 1 10 and counterbore 112.
To assemble the interconnector 86, retaining member 94 is slideably fitted into bore within housing 88 until annular shoulder 110 abuts shoulder I18. Explosive lead 92 is then inserted into bore 106 of retaining member 94 and the second retaining member 96 is thereafter positioned over lead 92. Due to its larger outer diameter retaining member 96 is interference fixed in position as shown in FIG. 3.
The end portions of interconnector 86 constitute male connectors which cooperate with the end connectors 10 forming an operational connection between two lengths of mild detonating cords. As hereinbefore described and best seen in FIG. 4, cavity 50 receives the walls of housing 88. Each end portion of interconnector 86 is provided with a projection 120 which fits within the slot 52 of end connectors 10. When a connection between an end portion of interconnector 86 and an end connector 10 is performed, the collar 14 of end connector 10 is urged forward against the bias of spring washer l9 and slipped over the end portion of the interconnector assembly with projection 120 being received in slot 52. Collar 14 is then rotated to bringing the collar into its working position by the camming action of the projection 120 in slot 52 aided by the action of the spring washer. This position being limited by the abutment of shoulders 36 and 46. Further, the edge surface 122 of the interconnector assembly 86 abuts the ring member 18 thereby providing a tight fitting connection.
FIG. 4 illustrates the interconnector 86 passing through an opening 124 of a wall 122, such, for example, as a bulkhead of a ship or submarine, and fastening the annular lip 90 thereto by conventional means such as bolts 126 or the like. The beveled step 34 of inner member 12 is shown as cooperating in abutting relationship with the beveled shoulder 1 16 in the interconnector 86. It is apparent that base charge 12 will be positioned immediately adjacent an air gap 128 defined by the booster cup 72 and explosive lead 92.
In operation, the MDC is ignited, thereby creating a shock wave front which travels through the cord and is amplified by end coupler 58 to a sufficient magnitude to effect the initiation of base charge 56. Upon the initiation of base charge 56 booster cup 72 bursts and the expanding hot gases and fragments shoot across the air gap 128 thereby initiating the explosive lead 92. A reversal of the above process begins thereafter with a booster charge in the other end connector 10 being initiated by the explosion of lead 92 and finally resulting in a shock wave front being propagated through the second MDC.
Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the ap pended claims the invention may be practiced otherwise than as specifically described herein.
What is claimed as new and desired to be secured by Letters Patent of the United States is:
1. A quick-disconnect end connector for detonating cord comprising:
a connector adapter for receiving one end of said detonating cord;
a partially threaded cylindrical inner member having a first bore lined with polytetrafluoroethylene threadedly fixed to said adapter, wherein said mild detonating cord is positioned;
a substantially cylindrical collar member having a second axial bore therein, slidably positioned and partially enclosing said inner member;
a flexible ring encircling said inner member; and
a spring washer encircling said inner member and cooperating with said inner member and said cylindrical collar.
2. A quick-disconnect explosive connector assembly comprising:
an elongated interconnector having a housing including an external projection formed on either end portion thereof;
an explosive filled lead positioned within said housing; and
connector means for receiving an end of a detonating cord removably engaging opposite ends of said interconnector including,
a substantially cylindrical collar member having an axial bore and a helical slot formed therein,
a partially threaded cylindrical inner member slidably positioned within said bore and including a second bore having a polytetrafluoroethylene liner formed thereon, and
a flexible ring encircling said inner member.
3. A quick-disconnect explosive connector assembly comprising:
an elongate, cylindrical, interconnector having a projection formed externally thereon on each end portion thereof and having a beveled surface formed internally therein at each end portion;
an explosive lead centrally positioned within said interconnector;
at least one retaining member holding said explosive lead in position;
connector means removably engaging opposite ends of said interconnector for receiving an end of a detonating cord, said connector means including a collar member adapted to fit over an end portion of said interconnector and further having a helical slot formed therein receivable of said projection formed on said interconnector.
4. A quick-disconnect explosive connector assembly as recited in claim 3 wherein:
said connector means includes a partially threaded cylindrical inner member slidably positioned within said collar member, said inner member having a bore formed therein with a polytetrafluoroethylene liner formed thereon; and
a flexible ring encircling said inner member.