US3185090A

US3185090A - Dual shaped charge separation system

Info

Publication number: US3185090A
Application number: US255571A
Authority: US
Inventors: William L Weber
Original assignee: Thiokol Corp
Current assignee: ATK Launch Systems LLC
Priority date: 1963-02-01
Filing date: 1963-02-01
Publication date: 1965-05-25
Anticipated expiration: 1982-05-25

Description

May 25, 1965 w. L. WEBER 3,185,090

DUAL SHAPED CHARGE SEPARATION SYSTEM Filed Feb. 1, 1963 2 Sheets-Sheet l INVENTOR I 5 Mil/AM Z. N535? $2 M MW Afl'flP/V'hf May 25, 1965 w. WEBER 3,185,090

DUAL SHAPED CHARGE SEPARATION SYSTEM 1 Filed Feb. 1, 1963 2 Sheets-Sheet 2 V I. gag? figml lm Ji INVENTOR. IV ZZ/A/I l. A EBE/P QQ,MMMIA United States Patent Ofiice sas es Patented lit lay 25, 1%85 3,185,690 DUAL SHAPED CHARGE SEPARATKON SYSTEM William L. Weber, Levittown, Pa assignor to Thioirol llhernical Corporation, Bristol, Pa, a corporation of Delaware Filed Feb. 1, 1963, Ser. No. 255,571 8 Claims. (61. 102-24) The present invention relates to separation devices and more particularly to explosive separation devices for cutting a structure to divide it into separate parts.

While the separation device of the present invention may have other uses, it is particularly adapted for separating successive sections of a multi-stage rocket engine while in flight. Explosives have previously been used to separate casing sections of a rocket engine, but such devices have had a number of deficiencies. One particular deficiency is the possible failure of a system containing a single explosive charge. For example, if the separation device has a single charge and fails to detonate, the sections cannot thereafter be separated. To avoid this condition, two separate explosive charges can be provided so that an auxiliary explosive charge is available if the first one fails to operate. With such an arrangement, however, both charges are apt to be exploded simultaneously and produce twice the force required to separate the sections. Therefore, such a dual system requires larger parts to balance therback-blast produced by the explosion. Furthermore, such dual systems require dual ignition mechanisms and/or timing devices to detonate the charges successively. These additional parts are additive in increasing the weight, cost and complications of the resulting rocket engine.

One of the objects of the present invention is to provide a separation device with dual explosive charges initiated for successive operation from the same triggering mechanism and operable automatically when one charge detonates to disable the other charge.

Another object is to provide a separation device of the type indicated which utilizes linear shaped charge explosives to reduce the amount of explosive and size of the parts required to separate the structure.

Still another object of the present invention is to provide an explosive separation device of the type indicated which is of comparatively simple and compact construction, light in weight, economical to manufacture and having a high degree of reliability.

These and other objects will become more apparent from the following description and drawings in which like reference characters denote like parts throughout the several views. It is to be expressly understood, however, that the drawings are for the purpose of illustration only and are not a definition of the limits of the invention, reference being had for this purpose to the appended claims.

in the drawings:

FIGURE 1 is a side elevational view of a multi-stage rocket engine incorporating the separation device of the present invention;

FIGURE 2 is a side elevational view of the separation device showing the cylindrical strap in which the explosive charges are carried and the fuses of different lengths connected to a common initiator to explode the separate charges successively;

FlGURE 3 is a transverse sectional View taken on line 33 of FEGURE 2 to show how the strap of the separaion device is attached to the casing of the rocket engine and the separate linear explosive charges in spaced grooves therein;

FIGURE 4 is an enlarged view of a portion of the strap as viewed from line -ll of FIGURE 2 to show the explosive charges in the grooves and the fuses connected to each explosive charge through primers;

FiGURE 5 is a sectional View taken on line 5-5 of FIGURE 4 showing the fuses connected to one of the ends of the explosive charges through primers and the adjacent ends of said explosive charges crossing each other;

FIGURE 6 is a sectional view taken on line 6-6 of FEGURE 4 to show how the ends of each linear explosive charge abut each other to form a continuous ring, the primers in an initiator housing for initiating one charge and the fuses connected to primers in an arming block detachably connected to the initiator housing;

FIGURE 7 is a schematic perspective view of the dual explosive charges and fuses and showing how the ends of the charges cross each other, and;

FIGURE 8 is an enlarged plan View as viewed along the line 8-8 of FZGURE 6 to show how the ends of the explosive charges cross each other in the illustrated embodiment.

Referring now to the drawings, the invention is shown applied to a rocket engine 19 having a forward section it and a rearward section 12. Both sections 11 and 12 are enclosed in a common cylindrical casing 13 in which combustion chambers 14, 15 and nozzles 16, 17 for the respective sections are formed. The combustion chambers 1d and 15 of the sections 11 and 12 each contains a propellant, not shown, which burns and produces gases that flow through the nozzles 16 and 17 at high velocity to produce a forward thrust. The sections 11 and 12 are arranged in tandem so that the propellant in the rearward section 12 burns first, and when completely burned out, ignites the propellant in the combustion chamber of the forward section 111.

In accordance with the present invention an explosive separation device 20 is provided between the sections 11 and 12 of the rocket engine as shown in FIGURE 1. The separation device 20 comprises, in general, an annular band which surrounds the cylindrical casing 13 of the rocket engine it) and contains separate primary and secondary explosive charges for separating the sepa rate sections El and 12. The primary and secondary charges are so constructed and arranged that each is adapted to separate the section with a minimum quantity i of explosive and each cuts out the other when detonated.

As shown in detail in the drawings, the band is in the form of a strap 21 which engages the inner periphery for the cylindrical casing 13 of the rocket engine around its entire periphery, see FIGURES 1 and. 2. The strap 21 can be positioned at the interior of the casing as illustrated, or may be located at the exterior of the casing. "in either case the strap has spaced

grooves

22 and 23 extending around its entire periphery with each groove containing a linear explosive charge 24- or 25, respectively. Any suitable explosive may be used in the linear charges such as conventional mild detonating fuse, but preferably a shaped charge explosive is provided as shown in FIG- URE 3. ()nc particular form of shaped charge which has been found particularly effective comprises a metal sheathing surrounding the linear explosive charge and having a V-shaped recess 26 or 26' adjacent the surface of the casing 13 to be cut. Such a shaped charge construction reduces the amount of explosive required to cut the casing and tends to cut the casing cleanly in a radial plane. 7

Detonation of each of the linear charges 2 and 25 is initiated by a

fuse

27 or 28 connected to at least one end of each linear charge. In the embodiment illustrated in FIGURE 2, fuses 2'7 and 27 are connected to opposite ends of the linear explosive charge 24, hereinafter referred to as the primary charge, and separate fuses 2S and 2 8 are connected to the opposite ends of the linear explosive charge 25, hereinafter referred to as the secondary charge. The opposite ends of the

fuses

27, 27 and 28, 28 are connected to a single initiating element 2% to start all of the fuses simultaneously. However, the

fuses

27 and 27 are of shorter length than the fuses 28 and 23' so that the primary explosive charge 24 will be detonated first and, in case it fails, the secondary linear charge 25 will be detonated by the fuses 28 and 28'.

Y The fuses 27 and 28 may be of any suitable type to detonate the linear

explosive charges

24 and 25. Preferably, however, the fuses are of the mild detonating type which detonate the

linear charge

24 and 25 to cause them to explode. When mild detonating fuse is used the initiating element 29 may be a detonating cap to initiate all of the fuses simultaneously.

The annular strap 21 may be in the form of a split ring having an opening 31 at one side only, but in the illustrated embodiment, see FIGURES 2 and 7, the ring is made up of separate

semi-circular sections

32 and 33 with an opening 34 diametrically opposite the opening 31. As shown in FIGURE 3 the strap 21 has a rim portion 35 overlying the casing section 13 and in which the

grooves

22 and 23 areformed, and a laterally projecting flange 36'through which rivets 37 driven to attach the strap to the casing 13 of the engine.

The ends of each linear

explosive charge

24 or 25 extend into abutting engagement with each other, see FIGURES 4 and 6, and then project radially inward into an initiator housing 40 and laterally across the housing. Housing 40 is attached to the strap at opposite sides of the opening 31 by means of

bolts

41 and 42 which also holds the ends of the strap to form a continuous band. The ends of the linear explosive charge 24 extend laterally into

end primers

43 and 43, see FIGURE 5, and the ends of the linear explosive charge 25 extend laterally into end primers 44 and 44-. The fuses 27 and 27' for the linear explosive charge 24 have end primers 47 and 47'.

and fuses 28 and 28 for linear charge 25 have end primers 48 and 48' and all of the primers are located in an arming block 49 attached to the initiator housing 40 by machine screws 50. Thus, one end of the mild detonating fuses 27 and 27 are connected to the detonatingelement 29 at one end and to the end primers 47 and 47' at their opposite end; the primers 47 and 47' contact the

primers

43 and 43 when the separation device is armed; and the

end primers

43 and 43 are connected to the oppositeends of the linear charge 24.

Similar end primers

44, 44' and 48, 48' connect fuses 28, 28' to the opposite ends of the linear explosive charge 25 across the opening 31. In the illustrated embodiment each'separate

explosive charge

24 and 25 is divided into two sections with a relay between the intermediate ends for continging the detonation in either direction so that the sections act as a continuous charge. Thus, the linear explosive charge 24 is initiated at both ends and detonates toward the center and, if either end fails to detonate, the detonation is continued through the relay. If both ends of the primary linear explosive charge 24 fall to detonate, then the secondary linear explosive charge 25 is detonated at each end to insure operation of the separating device. In other words, four successive failures must occur to prevent operation of the separation device.

As an -alternative modification, separate fuses as shown at the top of FIGURE 7 may be substituted for the relay at the bottom of the figure and connected to the same or a separate initiator 31 to provide eight possible starting combinations instead of the four illustrated.

. The principalfeature of the present invention is the I arrangement of charges 24 and '25 so that when one of 4 explosive charge 24 abut each other and then one end extends laterally and inwardly into engagement with the end primer 43 and the opposite end extends laterally and inwardly into engagement with end primer 43, respectively. Also the

ends

25a and 25b of the linear explosive charge 25 abut each other and then extend inwardly and laterally in a direction opposite to the

ends

24a and 24b of the explosive charge 24 into the end primers 44 and 44', respectively. Due to the fact that each of the ends of the explosive charges extend laterally, the adjacent ends of the

charge

24 and 25 must cross each other at each end as illustrated most clearly in FIGURES 5 and 7. Thus, the detonation of the linear charge 24 will cut the linear charge 25 at both ends in the initiator housing 40. Should the linear explosive charge 24 fail to detonate then the linearcharge 25 will, when detonated, cut the linear charge 24 adjacent its ends. It has been found that when lead sheathed mild detonating fuse is used, that lateral detonation will not detonate the charge but only cut it into separate parts.

The present invention is intended to be used with a conventional linear charge sheathed in a metal such as lead, but preferably it is to be used with a linear shaped charge sheathed in metal such as lead and having a V- shaped recess overlying the surface to be cut. When a shaped charge is used, at least one of the

charges

24 and 25 will have its side overlying the secondary charge to cut it in a clean cleavage plane with a minimum of detonation. Preferably the ends of the shaped charge of the secondary unit is twisted so its V-shaped recess also overlies the primary charge and is in a position to cut it in a plane when detonated. One form of the invention having now been described in detail, the mode of operation is next explained.

Assuming for purposes of description that the separation device 20 is assembled on the casing 13 of the rocket engine 10 in the manner illustrated in FIGURE 1 with linear shaped

charges

24 and 25 in the

grooves

22 and 23. Let it further be assumed that the separation device 20 has been armed by attaching the arming block 49 to the initiator housing 40. Then each of the shaped

linear charges

24 and 25 have their opposite ends connected to one end of

fuses

27, 27 and 28, 28, respectively, through end primers and the other end of the fuses are connected to a detonator 29 adapted to be initiated by remote control.

When the rocket engine 10 is in flight and the rearward stage 12 has burned out, a signal is produced to initiate the starting detonator element 29. Initiating element 29 detonates the ends of

fuses

27, 27 and 28, 28' when detonating fuse is used. As the

fuses

27, 27 are shorter than the

fuses

28, 28, the opposite ends of the shaped charge 24 'will be detonated simultaneously through the

fuse end primers

47, 47' and 43, 43' before either end of the shaped charge 25 is detonated. Immediately upon detonation, the

ends

24a and 24b of the shaped charge 24 will cut the

ends

25a and 25b of the shaped charge 25 and segregate it from its fuses 28 and 28'. Continued detonation of the shaped charge 24 in the

grooves

22 and 23 will cut the casing 13 around its entire periphery to separate the section 12 from the section 11. Immediately after the separation of the sections, .the propellant charge in the section 11 will be ignited and the blast from its nozzle 16 will separate the section 12 from the section 11.

Fuses'2 8 and 28, initially detonated at the same time i V as the fuses '27 and 27', will then transmit its fdetonations through the

end primers

48, 48' and 44, 44 to the ends of the secondary shaped charge 25. However, as the

ends

25a and 25b of the shaped charge 25 have been cut, the detonation from the fuses will not be transmitted to the main body of the linear charge; Thus, when the shaped charge 24 is detonated the charge 25 is disabled so that only one charge is exploded.

In case of failure of either of the

fuses

27 and 27 to detonate either end of the linear shaped charge 24, the

fuses

28 and 28 will operate through the end primers 43, 4-3 and 44, 44 to detonate the opposite ends of the shaped charge 25 simultaneously. The ends 256; and 25b of the shaped charge 25 will immediately cut the

ends

24a and 24b of the shaped charge 24 which they cross to separate the latter from its fuses and thereby disable the shaped charge 24. The detonation of the shaped charge 25 will cut the casing 13 around its entire periphery to separate the section 12 from the section 11; as previously described.

In case one of the ends only of the shaped charges 2 and 25 is detonated by its respective fuse 2'7, 2'7 or 28, 2'5, then the end detonated will sever the end of the other shaped charge which it crosses and sever the casing 13. The detonation started at one end of a shaped

charge

24 or 25 is transmitted through the relay between sections of fuse and continues toward the opposite end and severs the end of the other shaped charge which it crosses. Thus, the separation device 2% of the present invention is operable upon detonation of any one of four ends which are initially detonated to separate the sections of a structure to be separated and automatically cut out and disable the other explosive charges.

it will now be observed that the present invention provides a separation device with separate explosive charges adapted for successive operation from the same triggering mechanism and operable when either charge is detonated to disable the other charge. It will also be observed that the present invention provides a separation evice utilizing linear shaped charge explosives to reduce the amount of explosive and size of the parts required to separate the structure. It will still further be observed that the present invention provides an explosive separation device which is of comparatively simple and compact construction, light in weight, economical to manufacture and having a high degree of reliability.

While a preferred form of the invention is herein illustrated and described it will be understood that changes may be made in the construction and arrangement of elements without departing from the spirit or scope of the invention. Therefore, Without limitation in this re spect, the invention is defined by the following claims.

What is claimed is:

1. An explosive separation device for separating a structure into separate sections, first and second linear explosive charges extending across an area of the structure to be cut, means for initiating explosion of the separate charges successively to provide a timed delay therebetween so that the second charge will be exploded if the first charge fails, and the separate linear explosive charges crossing each other adjacent at least one end connected to the initiating means whereby the charge first exploded cuts the other charge to prevent explosion of both charges.

2. An explosive separation device for separating a structure into separate sections, a plurality of linear explosive charges extending in generally parallel arrangement across the structure at the area to be cut, separate fuses for each of the separate explosive charges and of different lengths to cause one explosive charge to be detonated before the other, and the end portion of the explosive charge first detonated crossing the end of the other explosive charge to cut it before it is detonated by its fuse.

3. An explosive separation device for separating a structure into separate sections comprising a plurality of separate systems for cutting the structure, each of said systems having a linear shaped charge extending across the area to he cut and or" sufticient capacity to cut the structure, and means for operating only one of the systems comprising a separate fuse for each shaped charge, one fuse being longer than the other to initiate explosion of one shaped charge before the other, common means for starting said fuses simultaneously, the ends of the shaped charge of the system first exploded having end portions crossing the ends of the other shaped charge to cut the latter at both ends, and the system with the longer fuse being exploded u-pon failure of the system with the shorter fuse.

4. An explosive separation device in accordance with claim 3 in which the fuses are of the mild detonating type.

5. An explosive separation device for separating sections of a cylindrical missile casing while in flight comprising, a strap engaging the casing around its entire periphery and having separate grooves open at the side adjacent the casing, a plurality of separation systems for cutting the casing wall and each system having an explosive shaped charge in one of the grooves in the strap, a fuse for each system to initiate explosion of its shaped charge, the fuse for one system being longer than the fuse for the other system, a common element for initiating both fuses, simultaneously, so that the shaped charge of one system will be exploded before the shaped charge of the other system, and the ends of the shaped charge for the separate systems crossing each other adjacent the ends thereof whereby the shaped charge first exploded cuts the other shaped charge adjacent its end to prevent explosion thereof by its fuse.

6. An explosive separation device in accordance with claim 5 in which the strap has an opening through which the ends of the linear shaped charges extend, an initiator housing connected to the strap at opposite sides of the opening and having an opening therein into which the ends of the shaped charges extend and cross each other, primers on at least one end of each explosive charge, an arming block :detachably connected to the initiator housing and into which the ends of the fuses extend, primers at the ends of th fuses in the arming block and contacting the primers in the initiating block to detonate the explosive shaped charges.

7. An explosive separation device in accordance with claim 6 in which fuses and primers are provided at each end of each explosive charge to simultaneously detonate both ends of a charge.

8. An explosive separation device in accordance with claim 7 in which the shaped charge of each system is divided into semi-circular sections, a relay housing intermediate the ends of the strap into which the ends of the shaped charges extend, primers on the ends of the semicircular sections of corresponding shaped charge in contact with each other whereby each section of each shaped charge can be detonated from each end.

References @ited by the Examiner UNITED STATES PATENTS 2,543,057 2/51 Porter 102.24 2,996,985 8/61 Kratzer 102-495 3,024,727 3/ 62 I-lradel 102--23 3,107,641 10/63 Haynes.

3,108,540 10/63 Fletcher.

SAMUEL FEINBERG, Primary Examiner.

Claims

1. AN EXPLOSIVE SEPARATION DEVICE FOR SEPARATING A STRUCTURE INTO SEPARATE SECTIONS, FIRST AND SECOND LINEAR EXPLOSIVE CHARGES EXTENDING ACROSS AND AREA OF THE STRUCTURE TO BE CUT, MEANS FOR INITIATING EXPLOSION OF THE SEPARATE CHARGES SUCCESSIVELY TO PROVIDE A TIMED DELAY THEREBETWEEN SO THAT THE SECOND CHARGE WILL BE EXPLODED IF THE FIRST CHARGE FAILS, AND THE SEPARATE LINEAR EXPLOSIVE CHARGES CROSSING EACH OTHER ADJACENT AT LEAST ONE END CONNECTED TO THE INITIATING MEANS WHEREBY THE CHARGE FIRST EXPLODED CUTS THE OTHER CHARGE TO PREVENT EXPLOSION OF BOTH CHARGES.