US3762407A

US3762407A - Survival support device

Info

Publication number: US3762407A
Application number: US00247107A
Authority: US
Inventors: D Shonerd
Original assignee: Lear Siegler Inc
Current assignee: Lear Siegler Inc
Priority date: 1972-04-24
Filing date: 1972-04-24
Publication date: 1973-10-02
Anticipated expiration: 1990-10-02

Abstract

Apparatus for providing a breathable gas to an individual in an emergency situation is provided in practice of this invention. The apparatus contains a breathable mixture of gas for a prolonged period and, when actuated, provides about 10 minutes of gas to the user. The gas is contained at high pressure in a lightweight long tube coiled about a combined fill valve, pressure regulator, flow control, pressure gauge, and actuation mechanism. This assembly is in a canister and actuated by perforating a pressure containing diaphragm between the gas storage reservoir and the pressure regulator. The canister is connected to the back of a plastic hood that is fittable over a user''s head so that the canister is arranged during use at the nape of the user''s neck so as not to interfere with any emergency operations and, for example, to permit the user to wear a helmet or the like. Gas from the canister passes into the hood at a substantially constant rate and is vented as required through a check valve. An elastic band around the person''s neck limits leakage.

Description

United States Patent 1 Shonerd 1 Oct. 2, 1973 1 SURVIVAL SUPPORT DEVICE [75] "iifv'iifii? "fiav'id'E.ShOnerdQSama Barbara,

Calif.

22 Filed: Apr. 24, 1972 21 Appl. No.: 247,107

Related US. Application Data [62] Division of Ser. No. 141,781, May 10,1971.

Primary Examiner-Richard A. Gaudet Assistant Examiner-Henry J. Recla Attorney-Christie, Parker & Hale 57 ABSTRACT Apparatus for providing a breathable gas to an individual in an emergency situation is provided in practice of this. invention. The apparatus contains a breathable mixture of gas for a prolonged period and, when actuated, provides about 10 minutes of gas to the user. The gas is contained at high pressure in a lightweight long tube coiled about a combined fill valve, pressure regulator, flow control, pressure gauge, and actuation mechanism. This assembly is in a canister and actuated by perforating a pressure containing diaphragm between the gas storage reservoir and the pressure regulator. The canister is connected to the back of a plastic hood that is fittable over a user's head so that the canister is arranged during use at the nape of the user's neck so as not to interfere with any emergency operations and, for example, to permit the user to wear a helmet or the like. Gas from the canister passes into the hood at a substantially constant rate and is vented as required through a check valve. An elastic band around the persons neck limits leakage.

4 Claims, 11 Drawing Figures SURVIVAL SUPPORT DEVICE CROSS REFERENCE TO RELATED APPLICATIONS This is a division, of application Ser. No. 141,781, filed May 10, I971.

BACKGROUND Many situations put personnel in a temporary situation where breathing of the ambient environment is not practical. A typical situation of this sort occurs in shipboard fires where heavy smoke may be produced and effectively trapped in comparatments within the ship. Personnel within these compartments must evacuate immediately or face suffocation or severe smoke inhalation injury. When these personnel are deep within a ship, rapid exiting from the damaged and smoke-filled area may be virtually impossible in sufficient time to prevent suffocation or severe injury. It may also be desirable for personnel to remain at their stations for a limited period in order to perform various emergency tasks before evacuation. It may also be important that personnel rescue injured or incapacitated people within the affected area and, therefore, they must perform a moderate amount of heavy work during the time that the environment is not breathable.

Although but one example of an acute situation requiring auxiliary breathing apparatus has been mentioned, many other such situations will be apparent, such as various industrial environments where noxious chemicals may be present, or in ordinary police and fire work where smoke or noxious chemicals may be encountered without a significant amount of advance warning.

When there is advance warning of a requirement for auxiliary breathing apparatus, a variety of conventional equipment is available for self-contained breathing. A more difficult situation arises, however, where the emergency may occur without substantial prior notice, and personnel are required to operate in the potentially hazardous environment substantially continuously. Again, referring to a shipboard situation, personnel may work in an engine room or the like for months or years without encountering a dangerous situation wherein auxiliary breathing apparatus is required. When such a situation does occur, however, it is too late to rely on conventional auxiliary breathing equipment, which may be located at fixed stations in the vicinity.

It is, therefore, desirable to provide an emergency breathing apparatus which provides breathing support for survival of personnel who may be unexpectedly thrust into an emergency situation wherein the ambient environment is unbreathable. Such a survival support device should be lightweight and small volume so that it can be carried or worn by a person substantially continuously during their normal tasks so that is is always at hand when required. It should also have high reliability for long periods of time, substantially complete safety, be confortable to wear, and rapidly usable after prolonged storage.

BRIEF SUMMARY OF THE INVENTION Therefore, in practice of this invention according to a presently preferred embodiment, there is provided a survival support deivce including a plastic bag fittable over a person's head for excluding the external atmosphere, a check valve for permitting exhalation, and a pressurized supply of breathable gas connected to the bag in position for wearing at the nape of a user's neck. Preferably, the survival support device stores high pressure gas in an elongated tube protected by a surrounding canister and wound about a mechanism that permits long-term storage and instant actuation, as well as flow control for feeding the breathable gas into the plastic bag. Preferably, the mechanism includes a filling vlave, a pressure gauge, and pressure and flow regulators for gas measurement and control. Actuation and over-pressure protection are provided by a rupturable diaphragm and diaphragm perforating mechanism.

DRAWINGS These and other features and advantages of the invention will be appreciated as the same becomes better understood by reference to the following detailed description of presently preferred embodiments when considered in connection with the accompanying drawings wherein:

FIG. 1 illustrates a survival support device constructed according to principles of this invention in typical use;

FIG. 2 is a rear view of the hood portion of the device of FIG. 1;

FIG. 3 illustrates in cutaway perspective a pressurized gas storage and control system connectable to the hood of FIG. 2;

FIG. 4 illustrates in perspective a control mechanism for the system of FIG. 3;

FIG. 5 is a cross section through the control mechanism of FIG. 4;

FIG. 6 illustrates in perspective detail ofa diaphragm perforating plunger from the mechanism of FIG. 5;

FIG. 7 is an end view of the plunger of FIG. 6;

FIG. 8 is a rear view of another embodiment of survival support device constructed according to principles of this invention;

FIG. 9 is an end view of the gas storage and control system of the embodiment of FIG. 8; and

FIG. 10 is a side view, partly cut away, of the system of FIG. 9.

FIG. 11 is a longitudinal cross-sectional view ofa tool used for filling the reservoir.

Throughout the drawings, like numerals refer to like parts.

DESCRIPTION FIG. 1 illustrates a typical survival support device as one embodiment constructed according to principles of this invention. Modifications of the device illustrated in FIG. 1 are set forth hereinafter and adaptation to the components illustrated in FIG. 1 will be apparent. Thus, as illustrated in the embodiment of FIG. I, a user 11 of the survival support device has a hood l2 pulled over his head so that a breathable atmosphere can be provided within the hood.

In the illustrated arrangement, the hood 12 is made of two essentially flat pieces of plastic that are heat or otherwise bonded together to form a sacklike structure, the opening of which is encompassed by an elastic band 13 which during use fits about the user's neck to provide some degree of gas sealing. The front portion 14 of the hood 12 is formed of a transparent plastic so that the user can see through substantially the entire area and find his way out of a dangerous situation or perform useful tasks while still in the environment. The rear portion 16 of the hood need not be transparent, and is typically an opaque plastic sheet so as to be readily distinguishable from the-front portion. In addition, a greater variety of mechanical properties are available in opaque or translucent plastics than in transparent materials, and the structural requirements of the survival support device may be more readily accommodated by employing an opaque or translucent material for the rear portion 16 of the hood. The sacklike hood fits loosely over the head of the user so that he can continue to wear eyeglasses or the like while using the device.

In the center front of the hood, a conventional check valve 17 is mounted so as to permit gas to be discharged from the interior of the hood to the exterior and inhibit reverse flow of gas. The check valve can be located in other portions of the hood; however, it is preferred that the valve be located in a region close to the user's nose or mouth in order to best assure circulation of fresh air or other breathable gas into this region of the hood.

A gas canister 18, described in greater detail hereinafter, is connected to the rear portion 16 of the hood by fabric straps 19 (see also FIG. 2), which are buckled or otherwise fastened around the canister through metal loops 20 (FIG. 3) extending from its cylindrical surface. The straps 19 are integral with a fabric sheet 21 in the center back of the hood. The sheet is preferably adhesively bonded to the plastic back portion of the hood or it can be stitched to a fabric insert (not shown) on the inside of the hood for greater strength. The canister 18 is thus connected in close proximity to the rear portion of the hood near its lower edge so as to lie on the nape of the neck of the user during operation. By so positioning the gas canister 18, the users hands and arms are completely free and unconstrained; he can easily turn his head in any desired direction without significant hindrance; his view of the surroundings is not obscured; and he can perform various required tasks without problems due to the presence of the canister. The position of the canister at the nape of the neck further enables the user to go bareheaded or wear a battle helmet, fire helmet or the like, as desired. Since the gas reservoir is directly connected to the hood, there is no danger of catching a tube on surrounding objects and cutting off the supply of breathable gas, as would be the case if the canister were to remain at a persons waist or the like.

During normal situations, that is, in the absence of an emergency, the flexible hood 12 is preferably wrapped around the canister 18 or folded on one side of it to form a cylindrical package substantially the same size as the canister. This is preferably stored in a protective plastic bag or the like (not shown), which may be provided with a rip-open panel or seam, so that access to the survival support device is rapidly obtained in case of an emergency. The plastic bag with the canister inside is then conveniently carried on the users belt or some other convenient location until such time as it is needed. It will be clear, of course, that such survival support devices can also be provided at fixed locations in a region that may be subject to emergency situations rather than actually be carried by the personnel at all times. It is apparent, of course, that when it is carried directly on the person, the access to the survival support device is most reliable and quickest.

When it is desired to use the survival support device, it is removed from its protective container or bag (not shown) if employed, and the mask or hood 12 is unfolded from the canister 18. After starting the flow of breathable gas into the hood in a manner hereinafter described in greater detail, the person donning the hood merely dips his head forward so as to catch the front portion of the elastic neck band 13 under his chin. He then pulls the rear portion of the elastic neck band forwardly and upwardly across his face and over the top of his head, stretching it as much as required to do so. Such an operation also swings the gas canister 18 over the top of his head so as to lie in position at the nape of his neck. The elastic band 13 closes about the persons neck so that the open end of the bag is closed to provide a degree of gas sealing. The position of the transparent front portion 14 of the hood can then be adjusted, if needed, by shifting the entire canister from side to side, or by grasping the sides of the hood to twist it into position, or by grasping the check valve 17 in order to center it adjacent the users nose or mouth.

Meanwhile, fresh breathable gas is flowing into the hood, as hereinafter described, so that any noxious gases caught in the hood during the donning sequence are displaced through the check valve 17. The entire conning sequence and the purge of any remaining noxious materials within the mask are typically accomplished in less than about 20 seconds. Flow of breathable gas continues into the hood from the gas canister, and the person using the survival support device breathes in a normal manner with inhaled air being replaced by fresh breathable gas and exhalations largely expelled through the check valve. The volume of gas entering the hood is sufficient for the person to perform strenuous work for a period of at least ten minutes, such as may be required for escape from a hazardous situation. This may also permit sufficient time for performing emergency tasks or rescuing other personnel in the hazardous area. It will also be noted that two persons can share one survival support device by breathing from the open neck portion in turns, or a second person can breath gas from the check valve while being rescued.

HO. 3 illustrates in cutaway perspective a gas storage canister 18 as illustrated in FIG. 1. As illustrated in this embodiment, the canister is formed of two substantially similar cup-shaped halves 23, one of which may be flared outwardly slightlyand the other rolled inwardly at their adjoining edges so as to remain centered when fitted together. In a typical embodiment, the canister is only 5% inches diameter and 6 inches long. Mounted within the canister 18 is a double helical coil of high pressure steel tubing 22 within which gas up to about 5,000 psi may be stored. The elongated tube for storing high pressure gas is particularly advantageous, since it is capable of storing a reasonable volume of high pressure gas without a significant total weight. Thus, for example, a survival support device providing ten minutes or more of breathable gas can readily be made with a total weight of only about 3% pounds. The tube for gas storage has other advantages, such as, for example, in case of a leak as might occur from damage or perforation of the tubing, the gas tends to leak relatively slowly as compared with a single cylinder so that no substantially jetting action is caused by the escaping gas.

The tubing 22 can also be made ductile while still being capable of supporting the high pressure gases, so

that fragments and shrapnel are not produced in case of severe damage to the tubing. This latter property is evidenced by a test where a survival support device was perforated by a 0.308 caliber bullet fired transverse to the axis of the canister and which ruptured six coils of the high pressure tubing. The perforated canister rolled off its supporting six-in-wide shelf and fell to the ground without any noticeable lateral movement. There was no gas discharge sound discernible from 30 yards away, and no visible evidence of blast or jet propulsion. Gas which had originally been stored at 5,000 psi could be heard exiting from the tubing when observers reached the survival support device 40 seconds after perforation. The rigid canister surrounding the tubing gas reservoir may also help in minimizing jetting action in case of tube perforation since gas pressure should never build to substantial levels in the canister even when there is severe leakage from the tubing. The canister also helps inhibit shrapnel in case of damage, as well as preventing damage except in extreme situations.

The tubing 22 forming the gas storage reservoir is supported away from one end of the canister 18 by a supporting clamp 25, the ends of which engage the double helix of tubing and the center of which is connected to a control mechanism 26 mounted concentric with the coil of tubing for most efficient packing density. As seen in FIG. 3, the center of the clamp is between a nut 27 and a gas fitting 28 on the end ofa pressure regulator 29, described in greater detail hereinafter. The gas fitting 28 is also connected to the center of one of the end cups 23 of the canister 18 by a bolt (not shown) threaded into the end of the fitting. The gas fitting is on the low pressure side of the pressure regulator 29 and connects to a flexible plastic tube 31 which is passed through the side of the canister and thence through a grommet 32 (FIG. 2) to the interior of the hood. In this way gas from the regulator passes from the canister into the hood for breathing by the user of the survival support device.

The control mechanism 26 is further illustrated in perspective in FIG. 4 and in a cross-sectional view in FIG. 5. As illustrated therein, the control mechanism has a metal body 35 containing a variety of apertures and passages within which various portions of the control mechanism are positioned. The body and the associated mechanisms are preferably capable of withstanding an internal pressure of at least 5,000 psi to provide a substantial margin of safety when the gas res ervoir of coiled tubing is charged with a breathable gas at 3,500 psi. Such strengths are readily attainable since the entire control mechanism is small and the internal passages and chambers are also of small diameter. Oxygen or an oxygen rich mixture stored at 3,500 psi is sufficient for providing breathable gas for at least l0 minutes.

A small-diameter metal tube 36 is welded into the control mechanism body 35 at one end, and at the other end the tube has a conventional gas fitting 37 for connection to a mating fitting (not shown) at one end of the tubing 22 (FIG. 3) forming the principal gas reservoir. The tube 36 thus provides fluid communication between the control mechanism and the gas reservoir. The interior of the tube 36 communicates with a transverse passage 38 within the body 35. One end of the transverse passage 38 is closed by a sheet aluminum diaphragm 39, discussed in greater detail hereinafter.

The other end of the passage 38 communicates with a bore 41 into which a conventional pressure gauge 42 is threaded for indicating the internal pressure in the bore 41, and hence within the gas reservoir.

A passsage having a conical sealing surface 43 communicates with the bore 41 and is sealed by a ball 44 mounted in one end of a plug 46. The plug 46 includes a pair of opposed fingers 47 for holding the ball in place and substantially aligned with the axis of the plug. At its opposite end the plug 46 includes a socket 48 for a hexagonal wrench or the like so that the plug can be rotated in its threads to bring the ball 44 in tight engagement with the conical surface 43 to close the valve, or to withdraw the ball for opening the valve. A pair of passages 49 extend through the plug off of the axis thereof for passing gas through the plug from a threaded bore 51 in the body 35. Thus, in order to fill the gas reservoir, the plug 46is screwed out a short distance to raise the ball 44 off of the conical surface 43. Pressurized gas admitted through the threaded Bore 51 passes through the passages 49 and into the interior of the control mechanism body 35' so as to communicate through the tube 36 into the gas reservoir. After the reservoir has been charged to the desired pressure, the plug 46 is screwed down again to seat the ball against the conical surface and thereby close the valve. Although it is preferred to have the fill valve mounted in the control mechanism body, a fill arrangement can be provided at the end of the coil of tubing remote from the end connected to the control mechanism. A check valve type of fill valve can also be used, but the sealing reliability is not as high as the positive valve illustrated.

After the fill valve has been closed, the survival support device is ready for use and can sit on the shelf or be carried by a person for long periods of time without recharging. The pressure gauge 42 provides an indication of the pressure within the reservoir to confirm that a sufficient quantity of gas is stored for at least ten minutes of use when the device is activated. If the gauge indicates that the pressure has dropped due to slow leakage from the system, it is only necessary to reopen the fill valve to bring the pressure back up to the desired level.

Since the survival support device may sit on the shelf or be inactive for a prolonged period of time and then need to be activated rapidly and reliably on a moments notice, a one shot" actuation mechanism is provided. The aluminum sheet diaphragm 39 sealing the passage 38 is typically installed as a partially drawn shallow cup that is further deformed into the illustrated form ofa truncated cone by a retainer 52, thereby effecting a tight metal to metal seal between the diaphragm and the opposed conical surfaces on the retainer and the body. This tight seal persists for long periods of time without deterioration.

An actuator body 53 is threaded into a bore in the control mechanism body 35 coaxial with the passage 38. This actuator body 53 serves to press the retainer ring 52 tightly against the aluminum diaphragm 39 to hold it in sealing engagement. The actuator body 53 has a cylindrical bore 54 within which a plunger 56 is mounted. A conventional O-ring 57 seals the plunger 56 to the cylindrical bore 54 to prevent gas leakage when the system is actuated. During static conditions before the device is actuated, there is no pressure across the O-ring 57 since the gas pressure is retained by the diaphragm seal 39. The plunger 56 is biased towards the diaphragm 39 by a compression spring 58. The plunger is retained in a retracted position, as illustrated in FIG. by a pull pin 59, extending through a transverse hole 61 in the end of the plunger. The side of the pull pin 59 bears against the end of the actuator body 53 so that when the plunger is in its retracted or cooked position, the spring 58 is under compression.

At the opposite end of the plunger 56 from the pull pin is a perforating tip 62, also illustrated in the perspective view of FIG. 6 and the end view of FIG. 7. The tip 62 has a diagonal fiat face 63 at about 45 degrees to the axis of the plunger. A pair of flat faces 64 about 90 apart and parallel to the axis of the plunger intersect the flat face 63 so as to form a sharp point at the tip of the plunger adjacent the diaphragm 39. The tip 62 also has a rounded portion 66 which permits it to enter the end passage 38 upon actuation of the device. A gas relief slot 67 is provided in the tip 62 intersecting the diagonal face 63.

In order to actuate the survival support device, the pull pin 59 is withdrawn from the hole 61 in the plunger 56. A ring 65 (FIG. 3) is connected on the end of the pull pin on the outside of the canister so that it can be withdrawn quickly and easily in an emergency. The compression spring 58 then quickly drives the plunger inwardly and causes the tip 62 to perforate the aluminum sheet diaphragm 39. Gas contained in the gas reservoir flows through the perforated diaphragm by way of the slot 67 and into the bore 54 of the actuator body 53. A pair of transverse passages 68 permit the pressurized gas to flow from within the actuator body to a threaded bore 69 into which the pressure regulator 29 is threaded.

The diaphragm and associated actuator mechanism for perforating it thus keep the pressure regulator isolated from the high pressure gas in the reservoir until the survival support device is actuated and when the pull pin is pulled, the regulator is substantially instantly connected to the reservoir so that gas quickly flows into the hood.

The pressure regulator 29 has a post 71 threaded into the bore 69 in the control mechanism body 35. An axial passage 72 through most of the length of the post and ending in a transverse passage 73 permits gas to flow from the bore 69 into a small chamber 74 defined by the sides of the post and a movable piston 76. The end of the post 71 has a shallow conical depression that forms a blunt knife edge 77 around the end of the post. A cap 75 threaded on the post retains the piston 76 in position and compresses a compression spring 78. A recessed region in the inside end of the cap and/or in the end of the piston 76 forms a chamber 79 extending over substantially the entire end area of the piston.

An outlet fitting 81 having a conical cap end 82 fits into the cap 75 and is held in place by the nut 27. The conical end 82 thus tightly engages the inside of the cap to form a gas seal. A small diameter orifice 83 separates the chamber 79 within the cap from the balance of the outlet fitting 81 for limiting the flow of gas. The fitting 28 (FIG. 3) that provides gas communication to the hood is threaded onto the outlet fitting 81 when installed in the survival support device.

When gas flows through the passages 72 and 73 through the post 71 from the bore 69 of the control device, it fills the chamber 74. It can then flow past the knife edge 77 into the relatively larger area chamber 79 opposite the face of the piston. The flow of gas out of the chamber 79 is restricted by the small orifice 83 so that there is a pressure buildup within the chamber 79 that acts on the face of the piston 76. This increased pressure compresses the spring 78, thereby pressing the inside surface of the piston towards the knife edge 77 on the post. As the gap between the piston and knife edge closes, the flow of gas is constricted so that pressure within the chamber 79 can decrease as gas flows through the orifice 83. A balance between the pressure in the chamber 79 and compression of the spring 78 is quickly achieved so that the pressure in the chamber 79 remains substantially constant and, therefore, the flow rate of gas through the flow limiting orifice 83 is also constant. The areas upon which the high pressure gas within the chamber 74 can act on the piston are balanced so that the magnitude of the high pressure within the regulator has negligible effect on the pressure within the outlet chamber 79.

The volume of the outlet chamber 79 is less than 0.01 cubic inch and the diameter of the orifice 83 is typically 0.01 inch. With such dimensions the pressure in the chamber 79 is quite responsive and equilibrium is rapid. The small volume coupled with the orifice permits a single stage of pressure regulation to be used rather than a double stage, thereby reducing cost, weight, and volume.

Thus, it is seen that the regulator 29 is a combined pressure regulator and flow control so that substantially constant gas flow is obtained through the outlet fitting 81 despite gross changes in pressure within the gas reservoir. In a typical embodiment, the gas in the reservoir is initially at about 3,500 psi, and this pressure steadily drops towards ambient during the approximately ten minute useful life of a charge of gas in the survival support device being at about 250 psi after 10 minutes. Throughout this broad inlet pressure range, a substantially constant flow of gas passes through the outlet fitting 81 and hence into the hood 12 for breathing by the user thereof. Tests have shown that the pressure at the outlet of the regulator portion is readily maintained at 200 psi, :20 psi, over the entire range from about 5,000 psi down to 250 psi on the inlet side. Thus there is substantially constant gas flow into the hood over a 20 to 1 range of storage reservoir pressures. If the pressure drop across the orifice 83 had a 20 to 1 variation, the gas flow would need to be excessively high initially in order to be adequate near the end and the total usable time of the survival support device would be significantly curtailed.

The sheet aluminum diaphragm 39 seals the gas in the reservoir until such time as the pull pin is pulled, thereby releasing the plunger, perforating the diaphragm, and actuating the survival support device. The diaphragm also serves an additional function in assuring safety of the survival support device in case of over-pressurization. The thickness and strength of the aluminum sheet forming the diaphragm 39 is well known so that the pressure required to rupture the sheet can be determined. The thickness is, therefore, selected so that the diaphragm will burst at a selected pressure in excess of the pressure of gas in the reservoir and less than the pressure required to damage other components of the system such as, for example, the tubing forming the reservoir. With such an arrangement, the survival support device cannot be dangerously over-pressurized since such overpressurization would burst the diaphragm 39, permitting the gas to flow through the pressure regulator 29 to be safely exhausted through the hood at a nominal rate. In the absence of overpressurization, the diaphragm remains intact until actuation when the tip of the plunger pierces FIGS. 8 through illustrate another embodiment of survival support device constructed according to principles of this invention. In some respects, this embodiment is preferred to that illustrated in FIGS. 1 to 3 since it may be lighter in weight for the same total operating time, is somewhat more comfortable to wear, and occupies a smaller total volume. These advantages come about since the coiled tubing forming the gas storage reservoir is bent in a quadrilateral pattern rather than a circular pattern so that the interior space within the coiled tubing more closely conforms to the external configuration of the control mechanism 26. Thus, there is less unoccupied volume in the gas storage part of the system. In addition, the surrounding metal canister is dispensed with and the control mechanism is supported directly from the coiled gas reservoir tubing.

FIG. 8 illustrates in back view a hood 86 substantially identical to the hood 12 hereinabove described for fitting over a users head when the survival support device is activated. An elastic band 87 at the neck of the hood fits snugly around the users neck for inhibiting gas flow. Attached directly to the back of the hood is a sheet plastic muff 88, open at its opposite ends and having a lower flap 89 shown with one corner curled back in FIG. 8. The muff also comprises an upper flap 91, a corner of which is also curled back in FIG. 8. A embodiment of stainless steel tubing forming a gas reservoir 92 is contained within the muff 88. The gas reservoir 92 is placed within the muff and the upper flap 91 connected to the lower flap 89 by conventional snaps 93. The muff is made so that the plastic is tightly stretched over the reservoir 92 when the snaps are fastened, so that the gas reservoir is held in position to fit against the nape of a users neck when the hood is pulled over his head. As in the ebodiment hereinabove described, a plastic tube 94 conducts breathable gas from the gas reservoir through a grommet 96 into the interior of the hood 86 when the survival support device is activated.

Referring now to FIGS. 9 and 10, the gas reservoir 92 is seen in end view and side cutaway, respectively.-As

best seen in the end view of FIG. 9, the gas reservoir is in the form of a continuous double coil of tubing with an inner coil 97 concentric with an outer coil 98. Each.

of the

coils

97 and 98 is somewhat squared off so as to be bent in a quadrilateral figure with rounded corners as compared with the circular coils of tubing employed in the embodiment hereinabove described and illustrated in FIGS. 1 and 3. Thus, in the first embodiment the gas reservoir is in the form of a right circular cylinder, and in the embodiment illustrated in FIGS. 8 through 10, the gas reservoir is in the form of a cylinder having a substantially quadrilateral cross section.

Mounted within the inner coil of tubing 97 forming the gas reservoir is a control mechanism 126 substantially identical to the control mechanism 26 hereinabove described and illustrated in FIGS. 4 to 7. The body 135 of the control mechanism is approximately rectangular and closely fits within the inner coil of tubing 97 so that there is a minimum of unoccupied volume within the coils forming the gas reservoir. This more efficient utilization of the volume reduces the total size of the gas supply subsystem of the survival support device.

A bracket 99 having slightly curved ends 101 to conform to the shape of the tubing forming the gas reservoir is connected to the control mechanism 126 by a bolt 102. If desired, a shallow cup over the end of the reservoir can be used and this may afford protection for the gauge and keep the pull pin captive after the device is actuated. The length of the control mechanism 126 is less than the coiled length of the tubing forming the gas reservoir, and therefore the opposite end of the control mechanism 126 is bolted to a U-shaped bracket 103 illustrated in the cutaway view of FIG. 10. The U- shaped bracket 103 has wings 104 extending over the end of the gas reservoir 92 so that when assembled, the coils of tubing are clamped together and the control mechanism is firmly secured thereto within the inner coil. A high pressure gas tube 136 connects the body of the control mechanism 126 to the gas reservoir 92 by a conventional fitting 137 in the same manner hereinabove described. If the tube 136 is made sufficiently stiff, it may provide support for one end of the control mechanism, permitting deletion of one bracket.

At the end of the control mechanism approximately flush with the end of the gas reservoir 92 is a pressure gauge 142 for monitoring the state of readiness of the survival support device. A pull pin 159 attached to a ring 165 is employed in the same manner as hereinabove described for actuating the survival support device. Filling of the gas reservoir is accomplished at the opposite end of the control mechanism, which is recessed from the end of the gas reservoir. Thus, in both embodiments of survival support device described and illustrated herein, a filling tool elongated enough to fit down to the fill valve is employed so that it is not necessary to remove the control assembly from the reservoir for filling.

Such a special fill tool is illustrated in longitudinal cross section in FIG. 11. The fill tool has an inner end fitting having a threaded end 111 that is matable with the threaded bore 51 (FIG. 5) in the control mechanism. A suitable seal (not shown) may be employed between the inner end fitting 110 and the body of the control mechanism for preventing gas leakage when the fill tool is used. Threaded into the opposite end of the inner fitting 110' is a tube 112 of a sufficient length to provide gas communication between the inner end fitting 110 when threaded into a fill valve, and an external gas supply. Connection to the external gas supply (not shown) is made by an outer end fitting 1 13 threaded on the opposite end of the tube 1 12. Both the inner and outer end fittings are also welded to the tubing 112 after assembly to assure a gas seal and permanence of the connection. A transverse threaded bore 106 communicates with the interior of the outer end fitting 113 for connection in a conventional manner with a high pressure gas supply.

An axial passage 107 extends along the full length of the fill tool. A shaft 108 in the passage 107 extends along a principal portion of the length of the fill tool and has one end extending through the tube 112 to butt against the interior of the inner end fitting 110. A hexagonal socket 109 in the inner end of the shaft 108 mates with a hexagonal key 116 having sufficient length that an end thereof can extend beyond the end of the inner end fitting 110. A generally cylindrical sleeve 117 press fitted on the key 116 keeps the key captive within the inner end fitting. A flat side 118 on the sleeve 117 permits gas to flow along its length. A compression spring 119 biases the sleeve 117 and the key 116 towards the end of the fill tool so that the end of the key typically protrudes, as illustrated in FIG. 11. The socket 109 in the end of the shaft is sufficiently deep that the key can be depressed as required to permit assembly of the filling tool into the fill valve.

At the opposite end of the shaft 108 an O-ring 121 provides a gas seal to the outer end fitting 113. A shoulder on the shaft 108 bears against a bushing 122 which engages a conventional thrust bearing 123. A retainer 124 threaded into the outer fitting 113 preloads the thrust bearing to a degree that permits the shaft to be rotated during use. A hexagonal socket 125 is provided in the outer end of the shaft 108.

In order to use the fill tool, the threaded portion 111 is tightened into the bore 51 (FIG. of the control mechanism. The outer end fitting 113 on the fill tool is preferably hexagonal to permit such tightening. When the fill tool is tightened in the control mechanism, the hexagonal key 116 fits into the hexagonal socket 48 (FIG. 5) in the fill valve. The key and the shaft 108 are free to rotate as the fill valve stays fixed and the fill tool rotates as it is tightened in place. The shaft 108 can then be rotated by inserting a conventional hexagonal key (not shown) in the hexagonal socket 125 at the outer end of the fill tool. This motion is transmitted through the length of the fill tool so as to open the fill valve in the control mechanism by baking the plug 46 out of its bore. High pressure gas may then be admitted through the bore 106 in the fill tool to pass around the shaft 108 and past the sleeve 117 into the body of the control mechanism where it is transmitted to the gas reservoir as hereinabove described. After the reservoir is charged to the desired pressure, the fill valve is closed by rotating the shaft of the fill tool and the tool can then be removed and the survival support device is ready for use.

Although but two embodiments of survival support device constructed according to principles of this invention have been described and illustrated herein, many modifications and variations will be apparent to one skilled in the art. Thus, for example, three concentric coils of tubing can be employed to form a gas reservoir around a control mechanism to provide greater storage capability and, hence, greater operating time or, on the other hand, the total length of the gas reservoir can be decreased as the diameter is increased without change in the operating time. Modifications and variations in the arrangement within the-control mechanism can also be provided by one skilled in the art. Many other modifications and variations will be apparent, and it is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed is:

1. In a survival support device comprising:

a substantially impervious flexible bag sufficiently large to fit over a user's head and including a transparent portion adjacent at least a front part of the bag;

means for permitting gas flow out of the bag and inhibiting gas flow into the bag;

a hollow coil of high pressure tubing for containing a breathable gas at high pressure;

regulator means within the coil for maintaining a substantially contanst outlet pressure over a broad range of inlet pressures and a substantially constant flow from the outlet thereof;

actuator means within the coil for substantially instantly connecting the regulator means to the reservoir means;

means for supporting the coil from the bag at a rear portion thereof against the nape of a users neck, the improvement wherein,

the coil of high pressure tubing comprises at least an outer quadrilateral coil around the regulator means and actuator means which are substantially rectangular in shape; and

an inner quadrilateral coil substantially concentric with the outer coil and closely conforming to the shape of the regulator means and actuator means whereby the total volume of the gas supply is minimized.

2. In a survival support device as defined in claim 1 the further improvement comprising:

a diaphragm between the reservoir means and the regulator means, capable of withstanding a substantial pressure there-across;

a plunger having a perforating tip adjacent the diaphragm;

means for mounting the plunger for movement towards the diaphragm a sufficient distance that the perforating tip can penetrate the diaphragm;

means for biasing the plunger towards the diaphragm; and

a removable retaining pin for temporarily holding the plunger away from the diaphragm.

3. In a survival support device as defined in claim 1 the further improvement comprising:

a pressure gauge in communication with the coil of tubing;

a pressure containing fill valve in communication with the coil of tubing; and wherein the pressure gauge, the fill valve, and the actuator means are all accessible from the ends of the hollow cylinder.

4. In a survival support device as defined in claim 1 the further improvement wherein the transparent portion of the bag is flexible.

t i i i

Claims

1. In a survival support device comprising: a substantially impervious flexible bag sufficiently large to fit over a user''s head and including a transparent portion adjacent at least a front part of the bag; means for permitting gas flow out of the bag and inhibiting gas flow into the bag; a hollow coil of high pressure tubing for containing a breathable gas at high pressure; regulator means within the coil for maintaining a substantially contansT outlet pressure over a broad range of inlet pressures and a substantially constant flow from the outlet thereof; actuator means within the coil for substantially instantly connecting the regulator means to the reservoir means; means for supporting the coil from the bag at a rear portion thereof against the nape of a user''s neck, the improvement wherein, the coil of high pressure tubing comprises at least an outer quadrilateral coil around the regulator means and actuator means which are substantially rectangular in shape; and an inner quadrilateral coil substantially concentric with the outer coil and closely conforming to the shape of the regulator means and actuator means whereby the total volume of the gas supply is minimized.

2. In a survival support device as defined in claim 1 the further improvement comprising: a diaphragm between the reservoir means and the regulator means, capable of withstanding a substantial pressure there-across; a plunger having a perforating tip adjacent the diaphragm; means for mounting the plunger for movement towards the diaphragm a sufficient distance that the perforating tip can penetrate the diaphragm; means for biasing the plunger towards the diaphragm; and a removable retaining pin for temporarily holding the plunger away from the diaphragm.

3. In a survival support device as defined in claim 1 the further improvement comprising: a pressure gauge in communication with the coil of tubing; a pressure containing fill valve in communication with the coil of tubing; and wherein the pressure gauge, the fill valve, and the actuator means are all accessible from the ends of the hollow cylinder.