Automatic inflator

There is disclosed an inflator for the inflation of inflatable articles such as life vests and the like, such inflator being operated automatically upon being subjected to water as upon the ditching or parachuting of an aviator wearing a life vest provided with such inflator. In the preferred embodiment of the inflator disclosed, the automatically operating portion of it is embodied as an attachment to a known manually operated inflator, the resulting inflator being capable of operation both manually and automatically. The automatically operating portion of the inflator incorporates a latch which holds a plunger operated by a coil compression spring in cocked condition until the latch releases the plunger, which thereafter thrusts a gas-containing capsule against a piercing pin, so that the pin passes through the sealing diaphragm of the capsule. The latch is provided with a water-destructible member which retains the latch in plunger-cocking position until the water-destructible member is subjected to water in an amount sufficient to weaken it so that the latch releases the plunger.

This application is related to the pending application of Glenn H. Mackal, 
Ser. No. 931,271 filed Aug. 4, 1978, and to the pending application of 
Glenn H. Mackal, Ser. No. 931,432, filed Aug. 7, 1978. 
This application relates to an automatic inflator for inflatable articles 
such as life vests and the like. In the disclosed preferred embodiment 
thereof, the inflator is capable of operation both manually and 
automatically, the automatically operating portion of the apparatus being 
preferably embodied as an attachment to a previously known manually 
operated inflator, the resulting, combined device retaining its ability to 
be operated manually while adding the capability of being operated 
automatically upon its subjection to water as being submerged therein when 
employed with a life vest worn by a ditching or parachuting aviator. 
Automatic inflators have been previously proposed. Among such prior 
disclosed automatic inflators are the following: Muller, U.S. Pat. No. 
1,329,990, Spidy, U.S. Pat. No. 2,894,658, Waters U.S. Pat. No. 3,242,514, 
Fujimoto, U.S. Pat. No. 3,494,506, and Niemann, U.S. Pat. No. 3,997,079. 
Of these patents, only those to Fujimoto and Niemann disclose automatic 
inflators which are also capable of operation manually. In Fujimoto a 
level-operated cam, an automatic, water-responsive mechanism, and a gas 
capsule which is moved toward a stationary piercing pin are arranged in 
that order. The operation of the inflator manually by the lever-operated 
cam may well cause operation of the automatic inflator portion of the 
device, a result which is neither necessary nor desirable. In Niemann, 
although the automatically operating portion of the device is disposed in 
series in that order with the manually operating portion thereof and the 
piercing pin, a part of the automatically operating mechanism is disposed 
in a first, removable part of the housing and another part of the 
automatically operating mechanism is disposed in a second part of the 
housing, and remains therein when the first part of the housing is removed 
and the inflator is operated only manually. Further, the removal of the 
first housing part leaves the second housing part in open condition, 
vulnerable to its being fouled both by physical and atmospheric agencies. 
It is among the objects of the present invention to overcome the outlined 
disadvantages of the prior art and to provide and automatically operated 
mechanism, responsive to being immersed in water, to effect the piercing 
of a gas-containing capsule, which may be easily attached to and held 
securely as a part of a manually operable inflator which by itself is 
complete. The automatic inflator of the invention may be either supplied 
to the trade as a separate item, which can be easily attached to existing 
manually operated inflators, or the combined automatic mechanism and the 
manually operated inflator may be assembled and sold as a unit.

Turning now to FIG. 1, there is there shown a manually operated inflator 10 
which is substantially shown in Mackal U.S. Pat. No. 3,809,288, May 7, 
1974. Inflator 10 is attached by a fitting generally designated 11 to an 
inflatable article, a part of the wall of which is shwon at 12. A capsule 
14 containing gas such as CO.sub.2 under pressure is mounted within the 
hollow main body 24 of a housing, the housing being secured and sealed to 
the body 20 of the manual inflator 10 in a manner to be described. When a 
sealing means such as a diaphragm which spans the neck of the capsule 14 
is pierced, gas is released from the capsule and flows into a chamber 
within the body 20 from which it is discharged through the fitting 11, 
which is mounted and sealed in an opening 13 in the body 20. The piercing 
of the seal of the capsule 14 by the manually operated inflator 10 is 
effected by the turning of a lever 15 by a lanyard 17 about a pivot pin 18 
upon which it is mounted on tbe body 20, thereby to cause a cam 16 
integral with the level 15 to advance a piercing pin against and through a 
seal such as a diaphragm on the neck of the capsule. The lanyard 17 is 
provided with a handle 19 by which the lanyard may be pulled to fracture a 
frangible pin 21 which passes through aligned openings in the body 20 and 
through the level 15, as shown. The manual operation of the inflator 20 is 
illustrated in FIG. 5, which shows the lever 15 as having been swung 
clockwise, the automatic mechanism for thrusting the capsule toward the 
piercing pin then remaining cocked and inoperative. 
The automatic inflating mechanism, which is generally designated by the 
reference character 22, is composed generally of a hollow main body 24 
which is circular cylindrical throughout its main extent, but has a 
frusto-conical portion 25 at its axially inner end, portion 25 terminating 
in an externally threaded neck 26. The capsule 14 has an outer diameter 
somewhat less than the inner diameter of the main body 24 of the housing, 
so that the capsule may slide freely axially therewithin. In FIG. 2 the 
capsule 14 is shown in the position which it assumes after it has been 
mounted in the mechanism 22 but before mechanism 22 has been screwed onto 
the body 20 of the manual inflator 10. As shown in FIG. 2, the inner 
generally frusto-conical neck portion of the capsule rests upon a series 
of radially inwardly projecting lugs 23 on the portion 25 of the body 24, 
the externally threaded neck 27 of the capsule then lying fully within the 
threaded neck 26 of the body 24. When mechanism 22 is then mounted upon 
the inflator 10 with the plunger 44 in its cocked, axially outer, 
position, as shwon in FIG. 3, the capsule 14 has freedom of axial movement 
within the hollow body 24 from a position in which the rounded outer end 
of the capsule 14 engages the inner surface of plunger 44 to a member or 
diaphragm 34 of the capsule engages, but is not pierced by, the piercing 
pin 41. 
As shown in FIGS. 3, 5, and 6, the body 20 of the manual inflator 10 has an 
internally threaded opening 29 therein which threadedly receives the neck 
26 of the main body 24 of the housing. A single gasket generally 
designated 30 is employed to seal the neck 26 to the body 20 of the 
inflator, to seal the transverse inner end of the neck 27 of the capsule 
14 to the body 320 but to permit the capsule 14 to be thrust in the 
direction from right to left when the inflator is automaticcally operated 
to move the capsule 14 against the piercing pin of the inflator. To 
fulfill such functions, the gasket 30 has a radially outer, axially 
thinner annular portion 33 which is interposed between the transverse 
axially inner face of the neck 26 of the housing portion 24 when the 
housing is screwed home into the threaded opening 29 in body 20 of the 
inflator 10. The gasket 30 has a radially inner, axially thicker annular 
portion 38 which is disposed in alignment with the transverse annular 
surface of the neck 27 of the capsule 14 and extends axially toward it 
from portion 33 of the gasket and is telescoped within the neck 26 of part 
24. It will be seen that when the gas capsule 14 has been thrust to the 
left into the position shown in FIG. 6, the gasket 30 seals both the 
housing portion 24 and the gas capsule 14 to the body 20 of the inflator 
10, thereby preventing the leakage of gas from the connection 
therebetween. 
The diaphragm-like sealing member across the neck of the capsule has a 
thinner central portion 34 which is pierced by the active axially outer 
end 41 of the piercing pin. Piercing pin 41 is that which is shown in the 
application of Glenn H. Mackal Ser. No. 916,497, filed June 19, 1978 now 
abandoned, which is incorporated herein in its entirety. 
The piercing pin, which is generally designated by the reference character 
35, has an enlarged axially inner end which is slidingly received in a 
bore 36 in the body 20 of the inflator, the piercing pin being sealed 
therein by an O-ring 37. A coil compression spring 39 telescoped over the 
shank 40 of the piercing pin constantly urges the enlarged axially inner 
end of the pin into contact with the cam 16. The active, forward end 41 of 
the piercing pin is of frusto-conical shape, and has an angularly disposed 
outer or forward cutting edge. The cam 16 has a circular configuration 
past its high point, so that upon the swinging of the lever 15 into the 
position shown in FIG. 5, the active outer end 41 of the piercing pin 
remains within the neck of the capsule 14, gas escaping from the capsule 
through the annular space presented between the inner edge of the whole 
cut in the diaphragm 34 and the side surfaces of the portion 41 of the 
piercing pin. As shown in FIG. 6, the same gas escape path is presented 
between the inner edge of the whole cut in the seal 34 and the side 
surfaces of the portion 41 of the piercing pin. 
The Automatic Inflator Mechanism 
The automatic inflator mechanism 22 includes a piston-like member or 
plunger 44 which has a flared, yieldable axially inner sealing edge 45 
which sealingly engages the circular cylindrical inner surface 42 of the 
main body 24 of the housing. The member 44 has an upwardly concave, 
part-spherical inner surface 43 having generally the same shape and size 
as the upper (FIG. 2) end of the capsule 14. The housing is completed by a 
cap 46 which has a plurality of axially extending evenly-spaced grooves 48 
therein, the axially inner ends of the grooves 48 terminating in openings 
47 which lie axially outwardly of a continuous circular cylindrical skirt 
54 on the cap. The piston-like member 44 has an outwardly extending 
central stem having a smooth circular cylindrical portion 49 axially 
inwardly thereof and an axially fluted outer end portion 50. Portion 50 
extends through an opening presented between three equally-spaced axially 
outwardly extending guides 54 when the automatic inflator mechanism is 
cocked as shown in FIGS. 3 and 5. The stem 49, 50 may be of a color which 
is readily distinguished from that of the cap 46, so that the cocked 
condition of the automatic inflator mechanism may be readily discerned. 
The cap 46 is retained upon the main body 24 of the housing by the snapping 
of hook-like radially outwardly extending porjections 52 on the outer end 
of the body 24 through the openings 47 in the skirt of the cap, the hooks 
52 being securely engaged with the shoulders 55 at the axially inner ends 
of the openings 47 in the cap. The skirt 54 loosely fits over the outer 
end of the main body 24 of the housing so as to permit the ingress of 
water therebetween, there being provided an axial extension 56 between 
successive members 52 on the body 24 so as to prevent the ingress of 
foreign bodies into the interior of housing. The axially inner surface of 
the piston-like member 44 is of part-spherical shape, so as to receive 
therewithin the rounded outer end of the capsule 14. As shown in FIG. 2, 
the rounded outer end of the capsule 14 is spaced somewhat axially from 
the cocked spherical inner surface of the member 44 when the automatic 
inflator mechanism is cocked and the combination of the housing and 
capsule 14 have not as yet been mounted upon the manual inflator 10. 
It is to be noted that when the piston-like member 44 is in the cocked 
position shown in FIG. 3, a substantial space exists between the sealing 
means 34 of the gas capsule and the forward cutting end of the active 
portion 41 of the piercing pin. This permits the member 44 and the gas 
capsule 14, under the impetus of spring mechanism now to be described, to 
gain substantial speed in its movements toward the piercing pin, after it 
has become uncocked, before the sealing means 34 engages the portion 41 of 
the piercing pin. 
In its cocked position, shown in FIG. 3, the member 44 is constantly urged 
in a direction from right to left by a compressed coil compression spring 
62 which acts between a spring seat 64 on member 44 and a spring seat 65 
on a latching mechanism 61. The latching mechanism 61 coacts with an 
annular groove 59 on the stem 49 of member 44 to retain the member 44 in 
ints cocked position with the spring 62 under compression. The latching 
mechanism 61, which is shown more specifically in FIGS. 4, 11, and 12, is 
mounted in an annular seat 69 in the cap 46, the outer edge of the main 
portion 66 of the latching mechanism 61 abutting an annular shoulder 70 in 
the cap. The latching mechanism 61 is telescoped over the stem 50, 49 of 
the plunger 44 as shown in FIG. 3. 
Turning now to FIGS. 4, 11, and 12, the latching mechanism 61, which is a 
preferred embodiment is made of plastic material such as "Delrin" 
("Delrin" is the registered trade-mark for an acetal resin made and sold 
by DuPont) has an axially short sleeve 71 from the rear (right, FIG. 4) 
end of which there project inwardly a plurality of equally angularly 
spaced axially short radial posts 74 integral with sleeve 71 and with the 
body 66 of the latching mechanism 61. Flutes or cutout portions 67 therein 
facilitate the flow of water inwardly to the water-sensitive member of the 
latching mechanism 61. 
Extending forwardly from each post 74 is a circumferentially thin radial 
blade 72, blade 72 extending forwardly to terminate in the same transverse 
plane as the forward edge of the sleeve 71. A plurality of separate, 
axially extending segments 75 which are spaced circumferentially from each 
other or which approximate an axially split inner sleeve coaxial of sleeve 
or skirt 71 are integrally connected at their rear ends and lie between 
successive posts 74. The points of attachment of the rear ends of the 
segments 75 to the posts 74 are designated 76. Each segment 75 has a 
radially inwardly extending lug or tooth 77 integral therewith, the teeth 
77 being spaced a substantial distance axially forwardly of the points of 
attachment 76. The annular groove 59 in the stem 49 of the plunger 44 has 
diverging beveled end walls, the lugs or teeth 77 having a configuration 
generally conforming to that of the section of the groove 59 so that they 
fit therewithin when the plunger is cocked, as shown in FIG. 3. 
The forward ends of the segments 75 extend substantially axially forwardly 
of the forward edges of the sleeve or skirt 71 and the blades 72, as shown 
in FIG. 4. The forward ends 79 of the segments have their forward, 
radially outer edges beveled at 80 as shown, the radially outer edges 81 
of the segments, rearwardly of the beveled portion 80, being straight and 
lying along the surface of a circular cylinder in the position of the 
segments shown in FIG. 4. There is thus presented an annular space 82 
between the radially outer edges 81 of the segments 75 and the radially 
inner edges of the blades 72. 
Into such annular space 82 there is thus a thin, sleeve-like coil 84 of 
water-soluble paper which, when dry, is backed up between the radially 
outer edges 81 of the segments 75 by the radially inner edges of the 
blades 72 has sufficient strength to retain the segments in the position 
shown in FIG. 3 against the outwardly directed force exerted upon them by 
the interaction between the rear beveled wall of the groove 59 in the stem 
49 of the plunger and the correspondingly beveled rear edge of each of the 
lugs or teeth 77. It will be seen that the coil of paper 84 is under both 
tension and compression, the tension arising by reason of its engagement 
with the edges 81 of the segments 75, and the compression arising by 
reason of its being jammed between the radially inner edges of the blades 
72 and the immediately adjacent two segments 75. 
Upon the immersion of the inflator 10, 22 in water, as by reason of the 
ditching of an aviator provided with a Mae West life-saving vest, water 
seeps into the interior of the housing 24, 46 and weakens or dissolves the 
paper coil 84 to such an extent that the expansive force of spring 62 
drives the plunger 44, 49 forwardly so that it in turn drives the gas 
capsule 14 against the piercing pin and into the position shown in FIG. 6. 
As the plunger 44, 49 moves forwardly, the lugs 77 move out of the annular 
groove 59 and distort the inner ring or sleeve formed by the segments 75 
as shown in FIG. 6, the outer end of the stem 50 then sliding freely past 
the now pried-apart lugs 77 of the segments 75. 
Although the invention is illustrated and described with reference to a 
single preferred embodiment thereof, it is to be expressly understood that 
it is in no way limited to the disclosure of such a preferred embodiment, 
but is capable of numerous modifications within the scope of the appended 
claims.