US3059207A

US3059207A - Explosive disconnect

Info

Publication number: US3059207A
Application number: US70632A
Authority: US
Inventors: Richard H Baird
Original assignee: Lockheed Aircraft Corp
Current assignee: Lockheed Corp
Priority date: 1960-11-21
Filing date: 1960-11-21
Publication date: 1962-10-16
Anticipated expiration: 1979-10-16

Description

Oct. 16, 1962 R. H. BAIRD EXPLOSIVE DISCONNECT Filed Nov. 21, 1960 3 Sheets-Sheet l INVENTOR. RICHARD H. BAIRD Z Kgnt Oct. 16, 1962 R. H. BAIRD EXPLOSIVE DISCONNECT 3 Sheets-Sheet 2 Filed Nov. 21, 1960 INVENTOR. RICHARD H. BAIRD Oct. 16, 1962 R. H. BAIRD 3,059,207

EXPLOSIVE DISCONNECT Filed Nov. 21, 1960 s Sheets-Sheet 3 J sn i E' RICHARD H. g z x' l Agent rates tent 3,59,2d7. Patented Oct. 16, 1962 3,059,207 EXPLGSIVE DISCUNNEQT Richard H. Baird, Santa Cruz, Calif., assignor to Loci;- heed Aircraft Corporation, Burbank, Calif. Filed Nov. 21, 1960, fier. No. 70,632 8 Claims. (til. 339-45) This invention relates to pyrotechnic devices and is more particularly directed to an explosively actuated disconnect assembly.

The use of explosive power to perform various mechanical functions is well known, and many devices have heretofore been proposed utilizing this motive force to initiated their functioning. A few of these devices have been directed to the function of disconnecting electrical lines between different stages of missiles and the like, and their utility has been emphasized by the fact that they may be remotely operated with a minimum electrical impulse from a great distance. One of the devices of the prior art with which applicant is familiar has been linearly actuated by an explosive charge placed between the two components to be separated, and there has been no provision made for a closed system containment of the actuating gases produced from the explosion. These gases, of course, have an adverse chemical effect upon the surrounding structure in addition to contaminating the atmosphere in the vicinity of the explosion. Other devices have proven to be extremely violent in their reaction, often causing physical damage to delicate parts mounted near the disconnect assembly.

It is thus an object of the present invention to provide an explosively actuated disconnect mechanism which will non-violently cause a separation of a plug and receptacle to which it is connected.

Another object of the present invention is to provide such a device in which the high pressure gases generated from the actuating explosion are completely contained within the actuating mechanism thus preventing physical and chemical damage to surrounding parts.

An additional object is to provide an explosive disconnect assembly which is adaptable to providing disconnect function to a wide variety of connectors both for electrical, gaseous, and hydraulic lines, which is extremely reliable, which meets strict Government requirements, and which is relatively easy to fabricate.

Additionally, an object of the invention is to provide an explosively actuated disconnect mechanism which may be refunctioned a number of times without special part replacement other than the explosive cells.

A still further object of the invention is to provide a device of the type described which is quite insensitive to high and low temperature extremes, violent vibration, rapid acceleration, humidity and chemical corrosion.

With these and other objects in mind the invention will be more particularly described in connection with the accompanying drawings wherein FIGURE 1 is a view in perspective showing the various components of the invention in an exploded relation,

FIGURE 2 is an end elevational view of the invention,

FIGURE 3 is a view shown partly in section taken along line 3--3 of FIGURE 2,

FIGURE 4 is an end elevational view of the body assembly of the invention, and

FIGURE 5 is a view shown partly in section taken along lines 5-5 of FIGURE 4.

Referring first to FIGURE 1, the invention is shown in a fragmentary or exploded relation by which the interrelation of the parts is more easily explained. The numeral 1 indicates generally the overall assembly while numeral 2 denotes the stationary assembly such as is adapted to be permanently aflixed to the structural frame of a vehicle, chassis, or the like. Reference numeral '3 designates the disengageable assembly which is adapted to be disconnected from assembly 2.

Referring to stationary assembly 2, it will be seen that a bulkhead 10 is provided with a plurality of apertures 11 which are adapted to receive screws 1-2 interrelating with nuts 13 to securely fasten a receptacle 14' thereto. It is noted that bulkhead 1d may refer to any structural assembly such as a bulkhead or outer skin of a missile or the like or to any basic frame structure to which a disconnect assembly might be engaged. Receptacle 14 is shown to be an electrical assembly such as may be composed of a cylindrical housing 15 containing a plurality of electrical connector pins 16 and which is provided with a mounting flange 17 containing a series of apertures 23 to receive bolts 12. On the other side of bulkhead 10 are a plurality of electrical wires 18 forming an electrical cable,

,which wires are connected as desired to the pins 16. As

shown, a potting boot 19 surrounds the portion of the wires as they enter into cylindrical housing 15, which potting boot is adapted to be secured to a potting boot retainer ring 20 in a manner known in the art. Potting boot retainer ring 26 is desirably threadably attached to a portion of the cylindrical housing 15, and the potting boot 19 is filled or potted with a suitably chosen dielectric compound of conventionally available type. It should be noted that the inner surface of cylindrical housing 15 is provided with a series of spline grooves 21 which are adapted to mate with spline tabs on a plug portion which will be described hereinbelow. Also provided upon the outer peripheral surface of cylindrical housing 15 are a number of cam stubs 22 which serve an important function to be described hereinafter.

A feature of the invention resides in the attachment of a base plate 30, formed of a lightweight material of substantial strength such as heat treated alloy steel, to bulkhead 10 which is desirably accomplished by providing a number of apertures 31 which register with apertures 11 in base plate 10. It will be seen that base plate 30 is centrally, preferably coaxially provided with a large aperture 32, which is adapted to receive one end of cylindrical housing 15 therewithin. A number of cam stub slots 33 are provided around the periphery of center aperture 32 which register with cam stubs 22 on cylindrical housing 15 as the housing is inserted into the center aperture 32. Important to note is the fact that base plate 30 is provided with a pair of turned up backing flanges 34 which are preferably formed at right angles to the backing portion of base plate 30, these backing flanges being on opposite sides of the base plate member.

Referring now to the disengageable assembly 3, it will be seen that a plug 40, preferably cylindrical in shape, is shown which is composed of a cylindrical body portion 4 1 having an outside shoulder 12 about the central periphery thereof. A series of spline tabs 43 are provided which are generally parallel to the axis of the plug member. The other end of cylindrical body portion 41 is preferably provided with a threaded surface 44'.

Adapted to cooperate with the base plate 3G in a manner which will be more particularly described hereinbelow is a body assembly &9 which is comprised of a body member 50 shown to be generally rectangular in shape and which is provided with a centrally located passageway 51 extending therethrough. It is important to note that the peripheral walls 52 of passageway 51 are provided with at least one and preferably three spiral camming grooves 53 which gently descend from and open upon the surface of body assembly 49 next adjacent plug 40. Desirably, these spiral camming grooves 53 extend over approximately 'a ninety degree arcuate portion of the peripheral walls 52 of passageway 51.

As best seen in connection With FIGURES 2 and 3, body member 50 is provided with at least one pair of interconnected shafts, one shaft of each pair being a squib shaft as at 54 and the other, a piston shaft as at 55, preferably formed at right angles to squib shaft 54, and interconnected thereto through aperture 56. It should be noted that squib shaft 5 4 does not extend completely through body member 50 but stops considerably short of the opposite surface from which it opens to insure that the wall between the bottom of the shaft and the other side of body member 50 is structurally substantial. It is noted that body member 51) is formed preferably of a lightweight metal such as aluminum, magnesium, or the like.

Piston shaft 55 opens upon a side surface such as 58 of body member 50 and is provided with an enlarged portion 59 about the periphery thereof. A piston 65 is slidably journaled within piston shaft 55', it being noted that piston 65 is provided at one end thereof with a pair of spaced radial flanges 66 which form a groove therebetween which is adapted to receive an O-ring 67. The diameter of each radial flange 66 is just slightly less than the internal diameter of the piston shaft 55, thus furnishing a guiding surface to insure a smooth sliding fit at that end of the piston. The opposite end of piston 65 is preferably rounded and is adapted to be received within a piston guide bearing 68 which is inserted into the enlarged portion 59 of piston shaft 55. It is noted that this piston guide bearing is preferably of metallic material which may contain a self lubricated bearing surface as desired. Threadably received within squib shaft 54 is a squib 70 containing an explosive charge which may be electrically initiated. Squibs of the type best suited for use in connection with the invention are commercially available, it having been found that M79 Mod. VIII or M130 Mod. I available from McCormick iSelph Associates (Hollister, California) are particularly suitable. A similar structure is provided at the opposite end of body member 50, including a squib shaft 54-, piston shaft 55, containing a squib and piston assembly respectively as described immediately above. The squib assemblies are sealed into engagement with the body member 5t} through 0-rings '71.

In addition to spiral camming grooves 53- formed Within peripheral wall 52, an inwardly extending shoulder 74- is provided next adjacent the outer surface 75 of body member 50. In fabricating the disengageable assembly 3, plug 40 is inserted into the aperture in body member 50 so that flange 42 engages with shoulder 74-, preventing the plug 40 from passing completely through the body member 50. Plug 4t} is retained in this position by means of a potting boot retaining ring 8 1 which is adapted to be threadably engaged with threads 44 on plug 40. Desirably, a radial, annular spring washer 8th is provided between flange 42 and shoulder 74 to insure that a positive electrical contact is maintained between the plug 40 and receptacle 14. This spring washer St} is inserted over threads 44 on the cylindrical body portion 41 of plug 40 and assures that potting boot retaining ring 81 is not tightened down upon the threads to such an extent that plug 40 is not freely rotatable as it is thus secured within body member 50. As in connection with stationary assembly 2, a potting boot 82 of polytetrailuoroethylene or the like is attached to the potting boot retaining ring 81, and a potting compound such as General Electric RTP-60 potting compound is implaced around the wires 83 extending through the assembly for connection with sockets (not shown) in plug 40.

Assembly and Operation In assembling the invention, the stationary assembly 2 is fastened to a bulkhead in the manner indicated above by the use of screws 12. Likewise, disengageable assembly 3 is assembled as described immediately above, and the two assemblies are ready for interengagement. To effect this interengagement, spline tabs 43 on plug 40 are 4 p keyed into the spline grooves 21 in cylindrical housing 15, thus effecting electrical connection between the wires leading into plug 40 and those wires 18 connected with pins 16. As plug 44} is inserted into receptacle 14, care should be taken to assure that cam stubs 22 register into spiral camming grooves 53 in body member 50, it being necessary to rotate body member 50 to effect a complete interengagement of the parts. A safety Wire is then connected and secured between backing flanges 34 and body member 50, it being noted that other known safety arrangements could be provided. The explosive disconnect assembly, thus ready for operation, is actuated by an electrical impulse which initiates one or both of explosive squibs 70. Referring to FIGURE 3, it will be apparent that the explosive gases generated will primarily expand into squib shaft 54 and thence through opening 56 into piston shaft 55, forcing piston 65 to move outwardly of the body member 50. In so doing, the end of piston 65, impinging upon backing flanges 34 will impart a reactive rotary movement to the whole of body member 50. As body member 50 is rotated, safety wire 100 is broken and cam studs 22, riding within spiral camming grooves 53 force body assembly 49 including plug 4t) outwardly. Manifestly, While both rotary and axial movement is imparted to body member 50, only an axial motion is imparted to plug 40 because of its rotatable mounting within body member 50. The electrical connection pins within receptacle 14 and the mating electrical contacts in plug 40 are not damaged.

It is noted that any propensity toward violent action or recoil of this system is conveniently damped out by spinning the body member 50 about the connector while disengagement of the connector or plug 40 occurs. Many actual tests have shown that disengageable assembly 3 is thrown only a few inches from stationary assembly 2 as the disconnection is accomplished, it being noted that previously available devices have violently reacted causing the disconnected portion thereof to move as far as twelve feet unless they are sooner stopped by intervening structure. Additional dampening is obtained by the twisting of the electrical harness.

Additionally, O-ring 67 in piston shaft 55 prevents escape of the explosive gases through this shaft and as the squib cap remains sealed, the explosive gases are thus effectively contained within the system.

It is noted that the disconnect device I have disclosed will effectively operate upon functioning one squib only, it being desirable, however, to function both squibs for the disconnect. A reliability approaching one hundred percent is thus provided. The unit has withstood severe temperature cycling, shock and vibration tests, and has remained operative from a low of 80 F. to a high of over 300 F. Similarly, a shock of 40 GS with a 2 millisecond rise time and 6 millisecond dwell time has been applied to a test assembly in each direction along three mutually perpendicular axes, with no mechanical failures or malfunctions being observed. Similar exhaustive testing has shown insensitivity to violent acceleration, vibration, humidity, and the like.

Referring to FIGURES 4 and 5, a modification of the invention is shown wherein a body member is provided with an insert sleeve 151. In this modification, sleeve 151 is provided with the desired spiral camming grooves 153 and is additionally provided with inwardly extending shoulder 174 which performs a function similar to shoulder 74 described in connection with FIGURES 1 through 3.

While sleeve 151 may be inserted within body member 150 in a variety of ways, it has been found desirable to shrink fit the two members together. In this procedure of assembly a wide temperature variation is provided between sleeve 151 and body member 150 so that the two members may be interfitted and allowed to cool, thus producing an extremely tight shrink fit. Operation of the device incorporating the modification disclosed in FIG- URES 4 and 5 is precisely the same as described above. The annular spring washer in this instance is positioned between the shoulder 174 and flange 42.

It should be understood that while the device has been described in connection with an explosive disconnect device for disconnecting electrical wiring, the invention has equal utility in effecting separation between lines carrying fluids and the like, the interaction being susbtantially the same if fluid line connectors were substituted, for example, for receptacle 14 and plug 40.

While certain preferred embodiments of the invention have been specifically disclosed, it is understood that the invention is not limited thereto, as many variations will be readily apparent to those skilled in the art, and the invention is to be given the broadest interpretation within the terms of the following claims.

What is claimed is;

1. A remotely actuable disconnect assembly comprising first and second interregistrable connectors, a body member rotatably secured around said second connector, explosive actuating means connected to said body memher for effecting rotation thereof relative to said first conncctor, said actuating means including a base plate secured to said first connector, said base plate having at least one backing flange outstanding substantially normally therefrom, at least one piston slidably mounted Within said body member at approximately a right angle to said backing flange, means for exerting pressure against said piston whereby said piston pressing against said backing flange causes a rotation of said body assembly relative to said first connector, and camming means connected to said body member for effecting a linear disconnecting movement of said body member and said second connector relative to said first connector.

2. A remotely actuable disconnect assembly as claimed in claim 1 in which said means for exerting pressure against said piston is an electrically actuated explosive squib, and in which the gases produced by the actuation of said squib are completely sealably contained within said body member.

3. A remotely actuable disconnect assembly comprising an interconnectable receptacle and plug, a base plate having at least one backing flange outstanding substantially normally therefrom secured to said receptacle, a body member rotatably secured upon said plug, said body member being formed with a centrally located passageway extending therethrough, a plurality of annular spiral camming grooves formed within the walls of said passageway, a plurality of cam stubs radially extending from the outer surface of said receptacle registrable with said spiral camming grooves, at least one piston shaft located in said body member, a piston in said shaft contacting and extending substantially normally to said backing flange When said plug is received in said receptacle, said body member being provided with a squib shaft therein extending inwardly from one surface thereof, and connecting with said piston shaft, and an electrically initiable explosive squib within said squib shaft.

4. A remotely actuable disconnect assembly comprising an interconnectable receptacle and plug, a base plate having at least one backing flange outstanding substantially normally therefrom secured to said receptacle, a body member rotatably secured upon said plug, said body member being formed with a centrally located passageway extending therethrough, an intimately fitting sleeve lining at least a portion of the walls of said passageway, one end of said sleeve terminating in an inwardly extending annular flange and the other end thereof provided with a plurality of annular spiral camming grooves formed in the walls thereof, a plurality of cam stubs radially extending from the outer surface of said receptacle registrable with said spiral cam grooves, at least one piston shaft located in said body member, a piston in said shaft contacting and extending substantially normally to said backing flange when said plug is received in said receptacle, said body member being provided with a squib shaft therein extending inwardly from one surface thereof and connecting with said piston shaft, and an electrically initiable explosive squib Within said squib shaft.

5. A remotely actuable disconnect assembly comprising first and second linearly interregistrable connectors, a pair of backing flanges connected to said first connector and outstanding substantially normally therefrom toward said second connector, a body member having a passageway extending therethrough, said second connector extending through said passageway and rotatably secured to said body member, actuating means in said body member actuable against said backing flanges causing rotation of said body member relative to said backing flanges, the passageway in said body member being formed with a plurality of annular spiral camming grooves, a plurality of cam stubs outstanding from the peripheral surface of said first connector receivable in said camming grooves, whereby as said body member is rotated said second connector is linearly disengaged from said first connector.

6. A remotely actuable disconnect assembly comprising first and second linearly interregistrable connectors, a pair of backing flanges connected to said first connector and outstanding substatially normally therefrom toward said second connector, a body member having a passageway extending therethrough, said second connector extending through said passageway and rotatably secured to said body member, camming means connected to said body member for effecting a linear disconnecting movement of said body member and said second connector relative to said first connector, said body member being formed with a pair of piston shafts extending at substantially ninety degrees to said backing flanges, a piston slidably, sealably journaled in each of said piston shafts with the outer end thereof in contact with said backing flanges,

a pair of closed squib shafts extending from the surface of said body member into the interior thereof, a passageway connecting each of said squib shafts respectively with said piston shafts, explosive electrically-actuable squibs sealingly engaged within and closing the surface opening of each of said squib shafts, whereby as said squibs are actuated, the explosive gases generated thereby remain sealed within said body member, and said body member is rotated in relation to said first connector.

7. A remotely actuable disconnect assembly comprising first and second linearly interregistrable connectors, a pair of backing flanges connected to said first connector and outstanding substantially normally therefrom toward said second connector, a body member having a passageway extending therethrough, said second connector extending through said passageway and rotatably secured to said body member, actuating means in said body member for effecting rotation thereof relative to said backing flanges, said passageway being formed with a plurality of annular spiral camming grooves, a plurality of cam stubs outstanding from the peripheral surface of said first connector receivable in said camming grooves, said body member being formed with a pair of piston shafts extending at substantially ninety degrees to said backing flanges, a piston slidably, sealably journaled in each of said piston shafts with the outer ends thereof, respectively, in contact with said backing flanges, a pair of squib shafts extending from the surface of said body member into the interior thereof, a passageway connecting each of said squib shafts, respectively, with said piston shafts, an explosive electrically-actuable squib sealingly engaged within and closing the surface opening of each of said squib shafts, whereby, as said squibs are actuated, the explosive gases generated thereby remain sealed within said body member, said body member being rotated in relation to said first connector, said second connector being thereby linearly disengaged from said first connector.

8. A remotely actuable disconnect assembly comprising first and second linearly interregistrable connectors, a pair of backing flanges connected to said first connector and substantially normally outstanding therefrom toward said second connector, said second connector having a threaded end portion and an annular shoulder about the mid section thereof, a body member having a large centrally located passageway extending therethrough and terminating at one surface in a passage of reduced diameter constituting an inwardly extending flange, said threaded portion of said second connector extending through said passageway to the extent that said flanges are substantially in juxtaposition, a potting assembly threadably engaged upon said threads extending through said passageway, the walls of said passageway being formed with a plurality of annular spiral camming grooves, a plurality of cam stubs registrable with said camming grooves extending outwardly from the periphery of said first connector, said body member containing two pairs of interconnecting shafts inwardly extending from non-parallel surfaces thereof, an explosive squib sealingly, threadably engaged Within a first shaft of each pair, and a piston member sealingly, slidably journaled within the second shaft of eachof said pair of shafts, the outer end of each of said pistons contacting said backing flanges, respectively, whereby upon initiation of said squibs, the expanding gases therefrom slide said pistons outwardly and against said backing flanges, thus effecting a rotation of said body memher and a cam operated disconnection of said first and second connectors.

References Cited in the file of this patent UNITED STATES PATENTS