US3510895A - Life saver for swimmers - Google Patents

Description

May 12, 1970 R. H. WYNNE LIFE SAVER FOR SWIMMERS Filed May 10, 1968 FEzZ P nnnunuul u l l United States Patent Int. Cl. B63c 9/18 U.S. Cl. 9323 12 Claims ABSTRACT OF THE DISCLOSURE A self-inflating flotation device, in the form of an elastic hollow band designed to be worn by a swimmer around his upper arm or neck, is divided into two sealed segments such that if one segment is defective or is punctured, the other will still inflate. Within each segment is a mixture of solid chemicals capable of generating heat when catalyzed into chemical action, and a non-elastic tube containing a condensed gas under pressure. When the device is stretched beyond a predetermined triggering point, the pressurized tube is opened, allowing the condensed gas to escape, vaporize and inflate the sealed segment. Simultaneously, the chemical mixture is brought into contact with a catalyst, so that the heat produced by the resulting reaction accelerates the vaporization of the condensed gas.

BACKGROUND OF THE INVENTION The most commonly used emergency flotation devices are waterproof belts or 'vests filled with a buoyant flock material. Their bulk necessitates large storage facilities and makes them cumbersome to the wearer.

Another type of known device is the self-inflating unit containing a gas-generating chemical cartridge, such as described in Pat. No. 2,097,542 issued to Wallin on Nov. 2, 1937. With such a device, the wearer may find it diflicult, in a moment of emergency and possible panic, to locate the cartridge or other triggering mechanism. Also, since the triggering mechanism is designed to be readily activated, the device must always be handled with care to prevent unintentional inflation. In addition, the device has but a single inflatable chamber, which a single puncture or defect will deflate. Moreover, because those chemical reactions that are the most eflicient in producing gas are also highly productive of heat, the device must either provide protection for the wearer from the heat, and thereby be bulky, or else utilize less efficient and therefore more bulky chemicals.

A third type of device is self-inflating by means of a cartridge of compressed gas. Such a device cannot be both quickly inflatable and non-bulky. For, if the gas is under low pressure and in the liquid state, it will inflate the device slowly, since vaporization of part of the gas cools the remainder and retards vaporization. On the other hand, if the gas is under high pressure, in any state, its container must be stoutly made and heavy, and if it is under low pressure and in the gaseous state, the gas itself will occupy considerable volume.

A further disadvantage of most known life-saving devices is that they are expensive. One reason for their cost is that they are designed and constructed to be capaisle of repeated use.

As evidenced by the prior art, many eflorts have been made over a period of many years to provide a satisfactory water safety device that swimmers might .wear. Today, few swimmers wear anything of the sort, although thousands of people die by drowning every year. Thus, it is evident that there still exists a real water safety problem, which the present invention is designed to solve.

SUMMARY OF THE INVENTION In a principal aspect, the present invention of a water flotation device comprises at least one elastic chamber that is inflated .by the release and vaporization of condensed or liquified gas, the vaporization being accelerated by an exothermic chemical reaction, wherein the release of the gas and the initiation of the chemical reaction are triggered by stretching the whole device.

It is thus an object of the present invention to provide an emergency flotation device for swimmers which is small, light and uncumbersome.

Another object is to provide such a device which is inexpensive and designed to be discarded after a single use.

Still another object is to provide such a device which has more than one inflatable chamber, so that a single puncture will not render the device entirely useless.

Still another object is to provide such a device which can be handled casually, or even roughly, without fear of premature inflation.

Still another object is to provide such a device which can be activated quickly and easily in an emergency, with no searching for the trigger.

Still another object is to provide such a device which is inflated by the action of eflicient, not bulky, chemicals with a minimum net production or absorption of heat.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of an arm band embodying this invention, divided into two segments, with the outer wall of one of the segments partially cut away to reveal the interior mechanism;

FIG. 2 shows a swimmer stretching an arm band so as to trigger it;

FIG. 3 illustrates the interior mechanism of one of the segments, the wall of the segment being cut away to reveal its interior;

FIG. 4 illustrates a segment at the moment of triggering with a longitudinal section of the pressurized tube cut away to show the internal arrangement; and

FIG. 5 is a cross section of the pressurized tube taken substantially along the line 55 in FIG. 4.

DESCRIPTION OF THE PREFERRED EMBODIMENT The preferred form of this invention is that of a hollow, elastic band designed to be worn around the upper arm or the neck of a swimmer. The arm type, which is shown in the drawings, is annular or ring-shaped and is put on by pulling it over the hand and up the arm. As adapted for the neck, the band would be linear and would be equipped with a fastening device, so that it would be worn like a necklace.

FIG. 1 shows an arm band divided into two segments 11 and 12. The outer wall 13 is made of a durable elastic waterproof material, such as rubber, capable of stretching so that the segments 11 and 12 will inflate whengas is generated inside them. The segments are sealed off from each other by seams 14 and 15 so as to insure that if one segment should be punctured or bedefective, the other would not be affected.

Inside each segment, as shown in FIGS. 1 and 3, is a pressurized tube 16 made of a strong flexible but nonelastic material, such as a thermoplastic resin, and preferably reinforced, as by external windings of cord. Tube 16 contains a precisely measured amount of a condensed gas under pressure, such as liquid sulfur dioxide (S0 Sulfur dioxide is a desirable choice because, first, it can be kept in liquid form by relatively moderate pressure, and second, it is quite efficient with respect to the volume of gas that evolves from a given weight of liquid. Tube 16 is folded in the way illustrated in FIG. 3 in order that the arm band may have a fiat shape and thus offer minimal obstruction to the flow of water when worn by a swimmer.

Variant forms of the invention are possible in which, for example, the container of condensed gas would not be a tube but would have some other shape. Also, the container of condensed gas might be located not inside the inflatable chamber but adjacent to it.

In FIG. 2 a swimmer is shown activating the device by stretching it. He does not have to locate a particular part of the mechanism in order to operate it. He simply takes hold of any part of the arm band and pulls. The inside of outer wall 13 is preferably lubricated so that it will slide easily over tube 16 when the band is stretched.

Alternative triggering mechanisms of the same general sort are possible, of such nature that, for example, the wearer might twist or pinch the arm band instead of stretching it. Such alternatives will fall within the scope of this invention if they display the feature that the device, in order to be activated, is taken as a whole and deformed in the specified way. By taken as a whole is meant that any part of the device, not one particular part, is manipulated.

The preferred triggering mechanism, by which stretching the arm band activates it, is illustrated in FIG. 3. The opposite ends 16a and 16b of tube 16 are sealed by caps 17 and 18 respectively, which caps are held shut by latches 19 and 20 cooperating respectively with fixed latches 19a and 20a. Trigger cords 21 and 22, both anchored in seam 15, are attached to latches 19 and 20 respectively. Anchored in seam 14 is tie cord 23, which is attached to the body of tube 16. There is slack in trigger cords 21 and 22 and in tie cord 23, so that the arm band can be stretched a certain degree, as when it is being pulled over the wearers hand, without causing it to inflate. But when the band is stretched beyond the amount of slack in the cords, the trigger cords 21 and 22 pull the latches 19 and 20, releasing caps 17 and 18. Further stretching pulls the caps away from the ends of tube 16.

Caps and trigger cords are provided at both ends of tube 16 to insure that even if some defect in manufacture should prevent one end of tube 16 from opening properly, the other end would still open.

When caps 17 and 18 are removed, the condensed gas inside tube 16 begins to escape, vaporize and expand, causing inflation of segment 12. The vaporization absorbs heat, the loss of which, if not compensated for, would retard or even halt the vaporization process and would also chill the wearers arm. A unique feature of the present invention is that the absorbed heat is replaced by heat newly produced by a chemical reaction, which is made to occur in the segment simultaneously with the vaporization.

There are, of course, many ways in which an exothermic chemical reaction of two chosen chemicals could be effected. FIGS. 4 and illustrate an arrangement whereby the reaction is made to occur inside tube 16, in the midst of the condensed gas, so that the heat generated is transmitted directly to the liquid, whose vaporization is thereby accelerated.

Inside tube 16 and extending through most of its length is a long fragile waterproof sleeve 24, sealed at both ends and containing a measured amount of a mixture 25 of two solid chemicals that will react with each other when catalyzed, such as sodium dioxide (Na O and powdered aluminum. Mixed or dissolved in the condensed gas inside tube 16 is a catalyst 26 capable of initiating the reaction of mixture 25. For the chemicals mentioned, the appropriate catalyst would be water, which is partially miscible with liquid sulfur dioxide.

Running the length of sleeve 24 and glued to opposite sides of it are two rip cords 27 and 28. One end of rip cord 27 is attached to the inside of cap 17, and one end of the other rip cord 28 is attached to the inside of the other cap 18. When the two caps are pulled away from the ends of tube 16 by the trigger cords 21 and 22,

the two rip cords 27 and 28 are pulled in opposite directions through the tube 16. Since the sleeve 24 is fragile and the rip cords are glued to it, their movement in opposite directions tears open sleeve 24 along its entire length. Then the condensed gas containing catalyst 26 comes in contact with the chemical mixture 25 and the desired chemical reaction occurs.

An alternative arrangement would place catalyst 26 in its own vessel, such as another sleeve, instead of mixing it with the condensed gas, This vessel might enclose or be adjacent to sleeve 24, inside tube 16.

Another alternative arrangement would omit sleeve 2 and rip cords 27 and 28 and would place the chemical mixture 25 outside tube 16, perhaps in the form of a coating on the outside of said tube. In this arrangement the catalyst 26 would be mixed with the condensed gas. When the caps 17 and 18 were pulled off the ends of tube 16, the emerging gas with the catalyst in it would come in contact with the mixture 25 and thus initiate its reaction.

Another alternative, also omitting sleeve 24 and rip cords 27 and 28, would utilize instead a fuse of the general sort used in blasting operations. The fuse would pass through the entire length of tube 16 and the two ends of the fuse would emerge through the sealed tube ends 16a and 16b. The fuse ends would be furnished with portions of a chemical mixture like mixture 25, capable of being catalyzed into reaction When tube 16 was opened, and capable of generating suflicient heat of reaction to ignite the fuse. The burning of the fuse, propagated through the length of tube 16, would provide the heat desired to accelerate vaporization.

Another alternative, instead of mixture 25 and catalyst 26, would utilize two separate chemicals of such nature that they will react exothermically upon contact. One chemical, such as water, would be mixed with the condensed gas inside tube 16 and the second chemical, such as aluminum carbide (A1 0 would be placed outside said tube. Or the two chemicals might be placed in a partitioned sleeve inside the tube 16, with means for ripping open the partition when the device is triggered.

Still another alternative would utilize the gas emerging from tube 16 as one of the two reactant chemicals. The second reactant would be placed outside said tube. If the condensed gas were sulfur dioxide, a suitable second reactant, which will react with gaseous sulfur dioxide on contact, would be sodium dioxide (Na O Reactant chemicals can be selected whose reaction will generate gas as well as heat. The additional gas thus generated will serve to augment that which vaporizes from inside tube 16. Water and aluminum carbide (Al C for example, generate methane gas in addition to heat.

The preferred embodiment described above, and the variants mentioned provide for a thermal balance in the functioning of the device, inasmuch as the heat absorbed by one action is approximately equal to the heat generated by another action occurring simultaneously. This feature of the invention makes it possible to utilize highly eflicient chamicals, without fear of excessive production or absorption of heat. Thus, the weight and bulk of the device can be held to a minimum. If the chemical combinations suggested above are employed, 7,000 cc. of gas, which is adaquate for an emergency flotation device, will be produced by a mere three-fifths ounce total weight of chemicals.

In the preferred embodiment and the variants described above, the internal arrangement of parts is designed to prevent accidental triggering. Because the trigger cords 21 and 22 and the tie cord 23 have slack in them, because the tube 16 is tough and flexible, and because the caps 17 and 18 and the latches 19' and 20 are located between lengths and bends of said tube and are thus protected by it from external impact and abrasion, the device can be handled casually, tossed about, dropped, or even stepped on without being prematurely inflated.

What is claimed is:

1. A self-inflating water safety flotation device comprising, in combination:

at least one inflatable chamber,

first and second inflation means of counteracting thermal types, said first means being endothermic and said second means being exothermic and the amounts of heat absorbed and produced respectively by said means being approximately equal, and at least one of said means providing gas for the inflation of said chamber,

triggering means to activate said inflation means.

2. The device of claim 1 wherein said triggering means comprises means to activate said inflation means whenever said device is deformed beyond a predetermined limit.

3. The device of claim 2 wherein said device includes at least one anchor point, and a container of compressed gas with entrance means, and said triggering means includes at least one slack cord connecting said anchor point with said entrance means, so that said cord is pulled taut and said entrance means is thereby opened when said, device is stretched beyond said predetermined limit.

4. The device of claim 1 including a plurality of separately inflatable chambers incorporated into a single integral device.

5. The device of claim 1 wherein said device takes the form of an annular band adapted to being worn on the arm.

6. The device of claim 1 weherin said first inflation means comprises a container of condensed gas positioned and adapted to release said gas into said chamber, and said second inflation means comprises means for accelerating the vaporization of said released condensed gas, and said triggering means comprises means to initiate said release of said condensed gas and to activate said acceleration means.

7. The device of claim 6 wherein said acceleration means includes at least two chemical reactants such that an exothermic reaction occurs when they come in contact, and said triggering means includes means for effecting said contact.

8. The device of claim 1 wherein said inflation means includes at least two parallel lengths of tubing whereby said device is given a generally flat shape.

9. The device of claim 7 wherein one of said reactants is enclosed in a readily opened vessel, and a second said reactant is positioned to come in contact with the first said reactant upon the opening of said vessel, and wherein said triggering means includes means for effecting said opening.

10. The device of claim 7 wherein said condensed gas comprises one of said chemical reactants.

11. The device of claim 1 wherein one of said inflation means comprises means for accelerating the inflation of said device.

12. The device of claim 1 wherein one of said inflation means includes a container of material productive of gas for inflating said chamber, said container being positioned and adapted to release said gas into said chamber upon activation of said device.

References Cited UNITED STATES PATENTS 724,279 3/1903 Goldstein 9326 X 2,536,847 1/1951 Harrow et al. 9-316 3,144,667 8/1964 Dobbs 9316 MILTON BUCHLER, Primary Examiner I. E. PITIENGER, Assistant Examiner

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