Hermetically sealed explosive release mechanism for actuator devic

Lee, D. A.

English

NASA Technical Reports Server

NATIONAL AERONAUTICS AND SPACE ADMINISTRATION 
WASHINGTON. D.C. 20546 
REPLY TO 
ATTN OF: GP October 16,  1970 
TO: ~ ~ ~ / ~ c i e n t i f i c  & Technical Information Divis ion  
Attent ion:  M i s s  Winnie M. Morgan 
FROM: ~ ~ / ~ f f i c e  of A s s i s t a n t  General 
Counsel f o r  Pa ten t  Matters  
SUBJECT: Announcement of NASA-Owned 
U.S. Pa ten t s  i n  STAR 
I n  accordance wi th  t h e  procedures contained i n  t h e  Code GP 
t o  Code US1 memorandum on t h i s  s u b j e c t ,  dated June 8, 1970, 
t h e  a t t ached  NASA-owned U.S. p a t e n t  i s  being forwarded f o r  
a b s t r a c t i n g  and announcement i n  NASA STAR. 
The following information i s  provided: 
U.S. Pa ten t  No. 
Corporate Source 
Supplementary 
Corporate Source 
Space Technoloqy Labs 
NASA Pa ten t  Case No.: XGS-00824 
Gayle Parker  
Enclosure : 
Copy of Pa ten t  
5 / 0 
5 (NASA CR OR TMX OR AD NUMBER) 
(CATEGORY) 
2 
NASA-HQ 
https://ntrs.nasa.gov/search.jsp?R=19710006603 2020-03-17T02:42:36+00:00Z
March 21, 1967 D. a. LEE 3,309,96 11 
HERMETICALLY SEALED EXPLOSIVE RELEASE MECHANISM 
F i led  June 30, 1964 
David A .  L e e ,  
INVENTOR 
- 
B 2 
beveled edge of the cylinder, so that it is unab!e to de- 
3,309,961 form any further and does not require great n~echanical 
HERMETICALLY SEALED EXPLOSIVE RELEASE strength to contain the pressures from the explosive 
MECHANISM cartridges. 
David A. Lee, Inglewood, Calif., assignor, by mesne as- One object of the present invention is to provide a 
signmenfs, to the United Slates of America as repre- ' hermetically sealed explosive release which 
sented by the Administrator of the National Aeronau- is capable transnlitting high tension loads prior to its tics and Space Administration 
Filed June 30,1964, Ser. No. 379,072 operation and provide an extremely fast reliable manner 
1 Claim. (C1. 89-1) of operation during release. 
Another object of the present invention is to provide 
This invention relates to a hernletically sealed explosive an explosively actuated release device in which no frag- 
release mechanism and more particularly to an explosively ments, gases, or contaminants of any nature are released 
actuated release device capable of transmitting high ten. to damage delicate articles or other fragile or contamina- 
sion loads prior to its operation, and providing all ex- tion sensitive devices nearby. 
tremely fast and reliable separation with no fragments, 16 Other objects and many of the attendant advantages of 
gases, o r  contaminants of any nature released during this invention will be readily appreciated as the same 
operation. Thus, the present invention may be used in become better understood by reference to the following 
close proximity to delicate and easily damaged devices, detailed description, when considered in connection with 
such as space vehicles, solar cells and other fragile or the accompanying drawings, wherein: 
contamination sensitive articles without hazard or dam- 20 FIG. 1 is a longitudinal sectional view taken on line 
age. The device may also be used safely in an explosive 1-1 of FIG. 2 and illustrating one preferred embodiment 
atmosphere. of the present invention; 
While explosively actuated pin pullers and similar re- FIG. 2 is an end view of the device illustrated in 
lease mechanisms have been used in the past, these de- FIG. 1; 
vices have used elastomeric or similar resilient seals of a 25 FIG. 3 is a fragmentary sectional view on a larger 
sliding nature to contain the products of combustion. scale illustrating the initial positions of the diaphragm, 
These seals do not perfectly contain the gases, as some piston, bolt, and retainer ring; 
leakage is permitted or occurs during the rapid increase FIG. 4 is a fragmentary sectional view illustrating the 
in pressure common to explosive reactions. distortion of the diaphragm, after actuation of the ex- 
Certain explosively actuated devices, such as safety 30 plosive cartridge, during its initial movement; 
and arming devices, and other mechanisms including elec- FIG. 5 is a view similar to FIGS. 3 and 4 illustrating 
trical switches, have been actuated by means of a bellows the final position of the diaphragm and piston after the 
or dimple motor, which is pressurized and forced to retainer ring has been sheared and the bolt is being ejected 
deform by an explosive, but these devices yield relatively from the body. 
low force, since the explosive pressure must be low 35 Referring now to the drawings in detail, and more 
enough to yield the metal without causing a fracture or particularly to FIG. 1, the explosive release mechanism 
leakage. 11 in one preferred embodiment consists of a generally 
One arming device for a fuse utilizes a preformed de- cylindrical body I2 having a pressure chamber 13. 
formable metallic diaphragm having a complex shape The body is provided with two radial openings into 
consisting of two concentric, reversely curved, annular 40 which the two explosive cartridges or detonators 14 and 
portions, which are subsequently deformed, after a long 15 are inserted, as indicated in the end view of FIG. 2. 
travel driving a cylindrical member, into a frusto-conical An axial opening in one end of the body 12 receives 
shape. This type of diaphragm, however, is subject to the bolt 16 which may be sealed in position by an epoxy 
fracture during deformation and possible leakage during or other suitable adhesive. The bolt 14 may be provided 
actuation of the device. 45 with threads, as indicated at 17 to engage a fitting at one 
Briefly stated, one preferred embodiment of the present end of an elongated cable (not shown). However, the 
invention consists of a body which nlay be secured to body 12 may be attached to a rigid or solid supporling 
one end of a cable or to a fixed support. The body is structure by any suitable means. 
provided with a pressure chamber into which one or two A larger threaded axial opening I S  in an opposite end 
explosive cartridges are inserted. The pressure challlber 50 of the body 12 receives a threaded retainer nut 21 which 
is closed off by a flat or frusto-conical diaphragm which is provided with a plurality of openings or recesses, such 
has a large area in contact with a piston mounted in a as those shown at 22 and 23, for engagemellt by a spanner 
cylinder formed in the body. The piston engages the wrench. 
head of a stud or bolt which is retained in a body by an The inner end of the retainer nut %I is bored out to 
annular shear disc or retainer ring. When either or both 55 forin a cylinder 24 positioned axially in the body to re- 
of the explosive cartridges are ignited, resulting in pres- ceive a piston 25. The inner end of the retainer nut also 
surization of the chamber, the diaphragm exerts a uni- engages the metal diapbragin 24 to hold it firmly in posi- 
form pressure against the piston moving it outwardly a11d tion against the body 12. An O-ring 27 may be posi- 
forcing the stud or bolt to shear the disc, wl~ich retains it tioiled to engage a chamfered or bmcle5 edge 28 formed 
inside of the body so that the opposite end of the cable, on the nut221 to provide a tight seal v!Jiich will prevent 
which ma), be secured to the bolt, is released rapidly and escape of gases, after aciuation of explosive cartridges 
reliably. During the entire operation, the diaphragm is I$ and SS. Tllc iill! %I 9 1 ~ 0  c ~ I : I ~ I I ~ c ? ~ ~  arountJ the 
conlpleteIy backed up by the piston except for a sinall icxier- e i d  of c:jjira6e? 24 io provide a chaii~fered annular 
peripheral portion which is deformed against an annular portion 29 adjacent the peripheral portion of diaphragm 
beveled edge in the body adjacent to the inner end of the 65 26. This detail is ciear!y shown in FIGS. 3, 4, and 5 on 
cylinder, so that exceedingly high pressures may be gen- a larger scale. 
erated to shear the retaining disc, t h ~ ~ s  permitting the Another bolt or stud 36 is likewise provided \vith 
device to withstand extremely high tension prior to re- threads 32 for engagement with a suitable fitting on the 
lease. After the diaphragm has been moved a short opposite end of a cable (not shown), or any other device 
distance sufficient to shear the retaining disc, the entire 70 which it may be desired to release. 
diaphragm is backed up by the piston and the annular The stud 31 has an enlarged head 33 which sets into 
8,309,981. 
3 4 
a recess 34 in the outer end of thc piston 25 The head snaps through after the explorive cartridges 14 and 15 
33 engagcs a retainer ring oi di,c 55 wliich fits slltigly ale actaaied to the oppos~te position shovin in FIG. 5. 
around a collar 36 formed on tile bolt 31 and IS secrried This action is similar to the movement of the boiiorn of 
in poiition by the nut 37 whir11 ih:erd, on to the 5haiiic nn oil Lan anci the action will be very rapid w~thout fall- 
38 of the boll 31. Nut 37 is providccl wiih radial re- 5 use of the material of which the diaphragm 26 is formed. 
cesses 39 which map also be engaged by a spanner wrench If the body 12 is rigidly secured to some supporting 
for tightening on the bolt 31. structure and the end of the cable attached to the bolt 
Ope] ntion 31, the explosive cartridge may obviously be inserted in 
an axial opening in place of the bolt 16 or in any other 
In the operation of the explosive release mechanism convenient location as long as it extends into the pressure 
of the present invention the two explosives caltridges 14 chamber 13. Although t\vo explosive cartridges 14 and 
and 15 are inserted in the openings in the body 12 lead- 15 have been indicated for the purpose of assuring action 
ing into the pressure chamber 13. Fittings on the op- in case either one fails, a single detonator may be ade- 
posite ends of a cable, for example, may be attached to quate and sufficiently reliable, and one detonator is suffi- 
the threaded ends 17 and 32 of the bolts and 31. l5 cient to actuate the release mechanism in any case. 
However, these bolts 17 and 3f. may be attached to any Obviously many other modifications and variations of 
other device which it is desired to release, or the body the present invention may be made within the scope of 
may be rigidly attached to some supporting structure and the following claim. 
the explosive release mechanism used to actuate any de- The embodiments of the invention in which an ex- 
sired movable element. 20 clusive property or privilege is claimed are defined as 
The detonators or explosive cartridges 14 and 15 may follows: 
be suitably connected by means not shown to any con- A hermetically sealed explosive release mechanism 
ventional timing mechanism or electrical actuator, for complising: 
example, on a spacecraft or missile where the cable may a body having a pressure chamber therein; 
be utilized for holding two stages together until SePara- Z B  a retaining sho~~lder  at one end of said pressure 
tion is desired. However, the explosive release mecha- chamber; 
nism of the piesent invention obviously has many other an elongated member having an enlarged head portion 
applications both in space and on the ground where it in said bodv: 
is desired to actuate or release the nlechanism by remote 
control with safety and reliability. 
The sequence of operation and the movement of the 30 
diaphragm 26, piston 25, and the head 33 of the bolt 31  
to shear the annular retaining ring 35 is clearly shown in 
the sequence of FIGS. 3, 4, and 5. 
In FIG. 3, the parts are shown on their initial assem- 33 
bled position In FIG. 4, the diaphragm 26 has started 
to deform and move the piston 25 and the retainer or an- 
nular ring 35 has already been sheared into two con- 
centric annular rings. As indicated in FIG. 4, most of 
the deformation of the diaphragm 26 takes place against 40 
the chamfered or beveled edge 29 of the retainer nut 21, 
as indicated by the arrow 41. It  will be apparent that 
the retainer ring 35 is held on the collar 36 by the nut 
37, pressing tightly against the head 33 of the bolt 31. 
In the final view of FIG. 5, the diaphragm 26 is fully 45 
deformed but is backed up by the piston 25 and the 
beveled edge 29, so that there is no great stress on the 
diaphragm itself and therefore shearing or cracking of 
the diaphragm 26 is almost impossible Leakage of the 
exhaust gases is effectively prevented by the O-ring 27 
which forms a seal between the chamfered edge 28 of 
the retainer 21 and the corner of the body 12 adjacent 
., 
an annular retaining ring interposed between and en- 
gaging said shoulder and enlarged head portion; 
a piston in said pressure chamber engaging said en- 
larged head portion, said piston being spaced from 
and adapted to he stopped by said retaining shoulder; 
a diaphragm attached to said body and engaging said 
piston, said diaphragm extending across said pres- 
sure chamber to prevent passage of gas therefrom; 
a bevelled support adjacent the point of attachment of 
said diaphragm to said body to support said dia- 
phragm upon pressurization of said pressure 
chamber, 
a retainer nut mounted in said body and having a bore 
for accommodation of said elongated member, said 
nut forming said retaining shoulder, said diaphragm 
being supported my said body and said retaining nut; 
whereby when said pressure chamber is pressurized, 
said diaphragm and piston is adapted to force said 
elongated member against said annular retaining ring 
to shear said ring and allow said elongated member 
to separate from said housing, said piston being 
stopped by said shoulder to support said diaphragm. 
References Cited bv the Examiner 
thereto which presses against the peripheral edge of the 
diaphragm 26. UNITED STATES PATENTS 
It will be apparent that the explosive release necha- 2,061,835 11/1936 Haines. 
nism of the present invention may be modified by pro- " 2,830,539 4/1958 Cecil --------------- 89-1 X 
viding a duplicate of the release mechanism s h o \ ~ n  on 3,119,302 1/1964 Barr ------------------ 89-1 
the left of FIG. 1 in dace of the solid bolt 96 to the 3,169,443 2/1965 Stott ----------------- 89-3 
right, so that both en& of the cable may be released 
simultaneously. The diaphragin 26 may also be folrnsd BENJAMIN A. BORCHELT, P ~ i r l l n l ~  ~.uaminer. 00 
as a frusto-conical disc which has its callvex side itlitialiy SAMUEL FEINBERG, ~ ~ ~ i ~ t ~ ~ ~ t  ~ ~ ~ ~ i ~ ~ ~ ~ . .  
extending into the pressure chamber 13 and buckles or 


Hermetically sealed explosive release mechanism Patent

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