US3161896A - Ram air inflated flotation bag - Google Patents

Description

Dec. 22, 1964 1. T. HOLT ETAL RAM AIR INFLATED FLOTATION BAG 2 Sheets-Sheet 1 Filed Nov. 20, 1963 INVENTORS A Home y Ira 7. Half Ham/a E. Wiaa'ows Dec. 22, 1964 l. T. HOLT ETAL 3,161,896

RAM AIR INFLATED FLOTATION BAG Filed Nov. 20, 1965 2 h tsh t 2 Fig. 4 INVENTORS Ira 7? Half Harald E. W/ddows Attorney United. States Fatent C) 3,161,896 RAM AIR INFLATED FLOTATION BAG Ira T. Holt and Harold E. Widdows, Albuquerque,

N. Mex., assignors, by mesne assignments, to the United States of America as represented by the United States Atomic Energy Commission Filed Nov. 20, 1963, Ser. No. 325,193 4 Claims. (Cl. 9-8) The invention relates generally to flotation means and more particularly to ram air inflated means in combination with parachutes for facilitating recovery of objects dropped into a body of water.

Recovery areas for vehicles such as missiles and the like are normally located over water because of minimal impact damage to components or packages carried by the vehicles and the lack of danger of impacting in inhabited areas. However, shortcomings of this procedure lie in the difliculty of locating these vehicles and in preventing them from sinking to a depth beyond that readily accessible by normal recovery procedures. Attempts to buoy such vehicles have heretofore met with only limited success because of the excessive space required. for stowage in the missiles or other vehicles. Also, the objectionable weight and low reliability of these previously known devices figured heavily in their limited acceptance.

An object of the present invention is to provide flotation means inflatable by the fluid medium through which it moves for furnishing a relatively light-weight buoying system to facilitate the recovery of packages or components dropped into a body of water.

Another object of the present invention is to provide a parachute arrangement with self-filled flotation gear.

A further object of the present invention is to provide a new and improved flotation means of inexpensive yet highly reliable construction.

Other and further objects of the invention will be obvious upon an understanding of the illustrative embodiments about to be described, or will be indicated in the appended claims, and various advantages not referred to herein will occur to one skilled in the art upon employment of the invention in practice.

Preferred embodiments of the invention have been chosen for purposes of illustration and description. The preferred embodiments illustrated are not intended to be exhaustive nor to limit the invention to the precise forms disclosed. They are chosen and described in order to best explain the principles of the invention and their application in practical use to thereby enable others skilled in the ant to best utilize the invention in various embodiments and modifications as are best adapted to the particular use contemplated.

In the accompanying drawings:

FIG. 1 shows an embodiment of a flotation bag of the present invention prior to its impacting the surface of a body of water;

FIG. 2 shows the embodiment of FIG. 1 in water with the flotation bag and signaling means in operation;

FIG. 3 is a fragmentary view illustrating one form of a coupling or attachment between the flotation bag and the main parachute;

FIG. 4 is a fragmentary view illustrating another form of the attachment between the flotation bag and the main parachute;

FIG. 5 is a fragmentary view showing the relationship of a ram air tunnelling member with the opening into a flotation bag;

FIG. 6 shows a modification of flotation bag construction; and

FIG. 7 shows a form of the present invention provided with an auxiliary flotation bag.

Referring to FIGS. 1 and 2, the present invention is shown being used with a recovery vehicle or package which may be, for example, from a rocket propelled missile or projectile (not shown). The vehicle generally indicated at 10 may contain any desired mechanisms, e.g., telemetry or recording equipment used in obtaining various high altitude data. The flotation bag of the present invention as shown at 13 may be stowed in a suitable compartment in the afterbody of the vehicle 10 along with a parachute 12 and a stabilizing parachute 14.

Parachute 12, which is shown as the main parachute for slowing the rate of descent of the vehicle 10, may comprise a canopy defined by a plurality of gores 17 which are interconnected by radials 18 extending between and securing together adjacent gores. About the periphery of the parachute and attached to each radial 18 there may be a riser or suspension line 16 which extends between the vehicle 10 and the parachute 12. The parachute preferably has a vent 19 centrally disposed for venting air from within the canopy for stabilizing the parachute in a well known manner. The gores, radials and suspension lines may be of any suitable material, e.g., nylon or the like.

As shown in FIG. 3, the flotation bag 13 is attached to the canopy of the parachute 12 by a plurality of lines or straps 21 sewn or otherwise secured to the radials 18 and the sides of the bag 13. Bag 13 is preferably in the form of a long tubular member closed at the upper end and having an air receiving mouth or opening 20 at the bottom. The opening 20 at the bottom of the bag 13 may be disposed over the vent 19 for receiving air from within the canopy of the parachute 12. This air passing from the canopy is normally at a pressure greater than ambient pressure and consequently when it leaves the canopy through the vent 19 it is in effect rammed into the bag 13 through the opening or mouth 20. The air pressures within the bag 13 are dependent upon several factors such as rate of descent, vent size, altitude, etc. and may vary from near ambient to as high as about 2.5 psi. during descent. The bag 13, which is preferably spaced from the canopy to facilitate the venting or spilling of air from the bag as will be described in detail below, may comprise any suitable material which is waterproof and of suflicient strength to withstand the pressures involved, e.g., a material found satisfactory is rubberized nylon similar to that used in life raft construction.

In order to stabilize the bag for maintaining it in correct alignment with the vent 19 during descent and to pull the flotation bag 13 from the parachute storage compartment (not shown) in the vehicle 10, a stabilizing parachute may be utilized such as indicated at 14. This parachute 14, which may be constructed similarly to parachute 12 or be of any other suitable construction, may be attached to the bag 13 so that when the stabilizing parachute is filled with air or at any desired subsequent time, its drag acts upon the flotation bag 13 and parachute 12 to withdraw them from the compartment. A bridle arrangement 23 or any other suitable coupling arrangement may be secured to the upper portion of the bag by sewing, bonding or the like and extend in the form of a suspension line 24 to the risers of the parachute 14.

Suitable position indicating or signaling aids may be placed atop the closed end of the bag 13 such as indicated by the several packages 25. These packages 25 may be attached or built into the top of the bag 13 and include radio beacons, lights, or other known signaling devices which may be activated by a timer or other desired means. Electrical power for operating the position indicating aids may be supplied by a battery pack 26 which may be disposed in any suitable location, e. g., inside the canopy of the parachute 12 and coupled to the packages 23 by an electrical conduit 27.

FIG. 4 illustrates another form of a satisfactory coupling arrangement between the parachute 12 and the flotation bag 13. This arrangement may comprise a porous webhing 29 having many air passages therethrough to facilitate the escaping of air from the enclosed space between the bag and the parachute. This webbing arrangement 29 may be of a suitable material such as nylon and secured to the bag and parachute in any suitable manner such as by sewing, bonding or the like.

Upon deployment of parachute 12 the air entering and trapped within the canopy becomes compressed with a portion of this pressurized air being relieved through the vent 19 to stabilize the parachute descent such as by minimizing oscillations. The pressurized air passes through the vent at a relative high velocity such as to be rammed into the bag 13 until the latter is filled with air. This rammed air builds up the pressure of the air in the bag to maintain the latter in essentially a fully extended condition. However, after a particular air pressure is attained in the bag, the excess air is spilled from the bag around the peripheral edge of the opening 20. Thus, the spacing between the vent opening 19 and the opening 29 in the bottom end of the bag should be sufficient to enable the excess air to spill from the bag 13 without adversely affecting the operation of the parachute 12 such as by blocking the vent 19 and thereby forcing air from the canopy about its periphery rather than through the vent 1%.

To assure that the air under the parachute canopy is passed through the vent and directly into the bag 13, it may in some instances be desirable to provide a funnellike member 31 as an air guiding extension as shown in FIG. 5. This funnel-like member 31 may be secured to the canopy about the periphery of the vent 19 and be so shaped as to converge towards the bag opening 20. The member 31 may have one end secured to the canopy so that the other end of the member 31 freely extends a slight distance into the bag opening for facilitating air flow into the bag and thereby providing discrete paths for the incoming air and the air spilling from the bag. With this arrangement the air is first channeled in the bag before being spilled therefrom, thus assuring that if the flotation bag is oscillating during descent the air venting from the canopy does not bypass the opening 20 into the bag.

In a typical operation of an embodiment of the present invention a vehicle 19, for example, one weighing about 150 pounds, may be separated from a propulsion vehicle (not shown) in any suitable manner such as by explosive bolts, etc. Upon separation the vehicle 10. descends towards a body of water and at a desired altitude or velocity, a mechanism such as a barometric switch or timer may be actuated to release the fall retarding parachute 12. Initially during this release the stabilizing parachute 14, which may be about three feet in diameter, is extended and filled with air. This in turn tends to slow the descent of the vehicle and stabilizes it, the canopy and bag 13 at this time being housed within the vehicle. The suspension line 24 may be secured to a portion of the vehicle 10 until the parachute 14 stabilizes and slows the vehicle to a desired rate of descent, e.g., about 300 feet per second. At this time the line 24 may be released from the vehicle 1th to pull the bag 13 and the main parachute 12 from the vehicle storage compartment. This pulling extends the bag 13 so that the air being channelled through the parachute vent 19 is readily passed or rammed into the bag 13 to fill the latter with pressurized air. When using a payload of about 150 pounds the parachute may be about five feet in diameter while the flotation bag 13 may be about one foot in diameter and seven and one half feet long. Also, the spacing between bag opening 20- and the top of the canopy may be about 6 inches. As mentioned above the excess air spills out of the bag and passes between the lines 19 or through the perforations in the webbing 25. When the vehicle 10 contacts the surface of a body of water, at, for example, an impact velocity of about eighty feet per second, the parachute 12 collapses and the vehicle 10 starts to sink and consequentially pulls a lower portion of the bag 13 into the water to trap the air within the bag by sealing the mouth or opening 20 with Water. Normally, the vehicle may submerge the bag sufficiently to fill from about one-sixth to about one-third of the bag 13 with water such as indicated by the dotted line 3 in FIG. 2. This partial filling of the bag with water further compresses the trapped air for making the air filled portion of the bag substantially rigid to maintain its tubular shape above the surface of the water. The pressures of the air within the bag during descent may be about 2.0 to 2.5 p.s.i., but can be up to about 6 or 7 p.s.i. during deployment. The pressure of the air within the bag after it is trapped by the water normally stabilizes at about one psi. The vehicle 10, in addition to providing the necessary weight for holding the mouth or opening 2% of the bag 13 under water, is disposed in the water at a location below the flotation bag, thus enabling the vehicle to also serve somewhat in the manner of a sea drogue for preventing excessive drift from the point of impact. As mentioned above the position indicating or signaling aids 25 may be actuated at any desired time.

Normally the flotation bag 13 contains only a single air cell or pocket, but it may in some instances be desirable to divide the bag into a pair of separate air cells 32 and 33 as shown in FIG. 6. Thus, if one air cell is damaged or leaks, the other air cell may buoy the entire assembly. The two celled flotation bag 13 may be formed by placing a pair of tubular bags in a side-by-side relationship and thereafter covering them with an outer layer of waterproof and air tight material such as used in the single celled bag. The air cells 32 and 33 may extend to a location adjacent the opening 20 of the bag 13 such that the funnel-like member 31 may extend into a single opening and yet be common to both cells. The two cell bag may be formed in other configurations or by other methods. For example, the placing of a suitable divider in a single celled bag may provide a satisfactory arrange.- ment. Also, there couldbe more than two air cells if desired.

In some instances, particularly where considerable time may lapse between the landing of the vehicle and the locating of the device, it may be deemed advisable to use a flotation assembly such as shown in FIG. 7. This fiotation assembly may comprise a flotation bag 13 filled by the medium through which it passes, as already described, and a gas filled bag 35 which is closed at both ends and secured to the ram air filled bag 13 in any suitable manner. The gas for filling this bag may come from a suitable source such as pressure bottle 36 which may be tripped in any desired manner. With this arrangement, which requires a larger storage space and greater weight than when just using bag 13, it is further assured that the assembly remains afloat a sufficient duration for facilitating recovery of the vehicle 10.

In applications where the stabilizing parachute 14 may interfere with the operation of signaling aids such as by collapsing over an antenna of a radio beacon as the vehicle descends into a body of water, it has been found that the stabilizing parachute 14 may be omitted. However, in order to use a flotation assembly without a stabilizing parachute, it may be desirable to slightly modify the flotation bag as above described by making it shorter in length and greater in diameter to aid in minimizing oscillations of the flotation bag. It may also be desirable to use with this modified flotation bag another parachute in place of the main parachute 12 that is capable of providing minimal oscillations such as well known in the parachute art, e.g., a guide-surface parachute or a ribboned parachute. This modified flotation bag and the main parachute may be removed from the storage compartment in the vehicle in any desired manner, such as, for example, by utilizing a pilot parachute which breaks-away from the flotation bag and the main para U chute after the latter are pulled from the compartment.

It will be seen that the present invention sets forth a novel flotation assembly which may be readily utilized in other applications, for example, an emergency situation aboard an aircraft which may require ditching at sea. In such instances communication facilities aboard the aircraft are often damaged, thus enabling the features of the present invention to be highly advantageous in rescuing survivors. Further, the light weight and compact nature of the present invention enables it to be used in applications where limited space is available.

As various changes may be made in the form, construction and arrangement of the parts herein without departing from the spirit and scope of the invention and without sacrificing any of its advantages, it is to be understood that all matter herein is to be interpreted as illustrative and not in a limiting sense.

We claim:

1. Combination parachute and flotation means comprising, when inflated, )a canopy having a centrally disposed aperture for venting air from the canopy, suspension lines afiixed to marginal portions of the canopy and extending therebelow for connection with an object, flotation means comprising an elongate tubular container having generally parallel oppositely disposed side wall sections and terminating in a closed upper end and having an open lower end disposed Wholly above said canopy and of diameter less than that of said canopy but greater than that of said canopy aperture with said open lower end in registry with said canopy aperture for air flow into and out of said container solely through said open lower end, connecting members circumferentially spaced about said canopy aperture and said container lower end and afiixed to said canopy immediately adjacent said canopy aperture and to said container adjacent said lower end maintaining said open end in registry with and spaced above said canopy aperture and so orienting the container to the canopy that the latter including its aperture is disposed wholly intermediate the container and said suspension lines, air flow egressing from within the canopy through the canopy aperture and through said open end to inflate the container and through the spaces intermediate said connecting members to vent air from within both the canopy and the container, said canopy upon descending into a body of water serving to force air out of the canopy through the aperture thereof and into said container through said open lower end thereof while sinking to submerge a lower portion of the container including said open end and trapping air within the container.

2. The combination claimed in claim 1 wherein there is provided a funnel-like construction having a lower part thereof extending from said canopy at locations about said aperture and an upper end part freely extending into the lower portion of said container through said open end thereof and being laterally inwardly spaced from walls of said container.

3. The combination claimed in claim 1 wherein the tubular container includes a plurality of air retaining pockets each extending from said closed end to a location adjacent said open end in side-by-side relationship.

4. The combination claimed in claim 1 wherein an other tubular container having closed opposite ends is secured alongside a portion of the first-mentioned tubular container, and wherein selectively actuable air supplying means communicate with said other container for filling the latter with air to supplement the flotation provided by the first-mentioned tubular container.

References Cited by the Examiner UNITED STATES PATENTS 1,802,325 4/31 Broadwick 244142 1,816,986 8/31 Packard 244145 X 1,864,298 6/32 De'Witt 244142 X 2,175,229 10/ 39 Swoiford 244142 2,196,947 4/40 Swolford 244142 2,587,564 2/52 Williams 9-8 X 2,774,561 12/56 Finken 244-145 2,974,913 3/61 Steinthal 244145 FOREIGN PATENTS 679,872 1/ 3 0 France.

FERGUS S. MIDDLETON, Primary Examiner.

Claims (1)

1. COMBINATION PARACHUTE AND FLOTATION MEANS COMPRISING, WHEN INFLATED, A CANOPY HAVING A CENTRALLY DISPOSED APERTURE FOR VENTING AIR FROM THE CANOPY, SUSPENSION LINES AFFIXED TO MARGINAL PORTIONS OF THE CANOPY AND EXTENDING THEREBELOW FOR CONNECTION WITH AN OBJECT, FLOTATION MEANS COMPRISING AN ELONGATE TUBULAR CONTAINER HAVING GENERALLY PARALLEL OPPOSITELY DISPOSED SIDE WALL SECTIONS AND TERMINATING IN A CLOSED UPPER END AND HAVING AN OPEN LOWER END DISPOSED WHOLLY ABOVE SAID CANOPY AND OF DIAMETER LESS THAN THAT OF SAID CANOPY BUT GREATER THAN THAT OF SAID CANOPY APERTURE WITH SAID OPEN LOWER END IN REGISTRY WITH SAID CANOPY APERTURE FOR AIR FLOW INTO AND OUT OF SAID CONTAINER SOLELY THROUGH SAID OPEN LOWER END, CONNECTING MEMBERS CIRCUMFERENTIALLY SPACED ABOUT SAID CANOPY APERTURE AND SAID CONTAINER LOWER END AND AFFIXED TO SAID CANOPY IMMEDIATELY ADJACENT SAID CANOPY APERTURE AND TO SAID CONTAINER ADJACENT SAID

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