IL302525A

IL302525A - Flexible life-saving flotation device

Info

Publication number: IL302525A
Application number: IL302525A
Authority: IL
Inventors: Shoham Oriya; Shoham Moshe
Original assignee: Sea Ark Tech Ltd; Shoham Oriya; Shoham Moshe
Priority date: 2023-04-30
Filing date: 2023-04-30
Publication date: 2024-11-01
Also published as: US20240359782A1

Description

FLEXIBLE LIFE-SAVING FLOTATION DEVICE FIELD The present disclosure describes technology related to the field of devices for providing flotation in water, using inflated balloon-like structures, especially for use in situations where a high level of flexibility is required of the device. BACKGROUND Drowning is a major cause of death worldwide, claiming the lives of more than 300,0people every year. Many of the drowning events occur in natural waters such as the sea and lakes in the absence of a supervising life guard, and many would have been preventable with use of a personal flotation device. In addition, there exist many types of devices whose function is to provide flotation to save people who find themselves in distress in bodies of water, not because of negligence or unpredicted circumstances during swimming or bathing, but rather as a result of a failure of another system. Some such examples are emergency landings in water of aircraft, or the sinking of watercraft in which the persons were travelling, or the need to pass through a water environment during professional, military or recreational activities. In such circumstances, devices such as safety vests, inflatable lifeboats, lifebelts or life buoys are used to provide emergency support in the water. Many previous references describe bracelets, armbands, jackets, belts and other inflatable devices designed for emergency use. Most of these inflation devices use inflation of the flotation balloon by means of the user of the device, who blows into a mouthpiece, which is connected through a one-way valve to the flotation balloon. One common example of such devices are the life-vests or lifejackets used in aircraft, which are intended to be inflated in times of emergency, by the breath of the wearer. However such types of devices are dependent on the consciousness and the physical ability of the user to inflate the device, and in emergency situations, this may not always be the situation. Therefore, flotation devices which do not require the breath of the user or wearer, may be preferable in some instances.

Some such inflation gas devices use chemical reactions that, when actuated, produce gas to inflate the device. In International Published Patent Application WO/2019/106677, for "Emergency Flotation Device with Chemical Reaction Chamber", having common inventors with the present application, there are described a number of novel devices using this principle, in addition to some earlier prior art devices. There also exist inflation devices of a third type, based on a charge of pressurized gas which is released on activation, into an inflatable flotation chamber. Such devices are preferred for emergency use since they can reduce the need of the user for activating the device, or can even be automatically self-activated. A number of such devices include US 547,808 to A. von der Ropp, for "Life Preserver", US 572,109 to T. Gordon, for "Life Preserver", US 1,117,639 to H.W.Cooey for "Portable Life Buoy", US 1,367,225 to W.H. Barker, for "Life Belt", US 2,028,651 to R.F. Dagnall et al, for "Release Mechanism for Pressure Fluid Containers, US 2,518,750 to E.H. Burkhardt for "Lifesaving Device", US 2,627,998 to C.W. Musser et al, for "Inflator for Pneumatic Lifesaving Devices", US 2,684,784 to R.G. Fox, for "Inflator for Pneumatic Life Preserving Apparatus", US 2,904,217 to J.T. Gurney for "Automatic Life Preserver", US 3,693,202 to TY. Ohtani, for Sea Rescue Ball Unit", CH 569611 for "Automatic Rescue Apparatus", WO83/042to J. Bissig for "Rescue Apparatus", WO 2014/077728 to P.P. Mukhortov for "Life-saving wristband", DE 202012007732 to G. Schmelzer for "Rescue bracelet or water airbag for bathers or swimmers, such as children, young people of all ages, adults, seniors", WO 2004/048193 for "Novel Inflation System for Inflatable Life Jackets" to P & P Utveckling AB, and WO 2020/208636 for "Emergency Flotation Device using Compressed Gas", having common inventors with the present application. Most of such previously described devices inflated by stored gas, have the disadvantage that a cartridge, cylinder or other vessel of the compressed gas is required, and such a cartridge, cylinder or vessel needs to be sturdy enough to withstand the pressure of the gas, and hence is expected to be of additional weight and volume, and generally protrudes from the flotation device, thereby conflicting with the intended characteristics of the device, which should be lightweight, of minimal size, and unobtrusive, in the sense that if the device is a garment, the garment can be worn without seriously impeding the movements of the person wearing it.

The disclosures of each of the publications mentioned in this section and in other sections of the specification, are hereby incorporated by reference, each in its entirety. SUMMARY The present disclosure attempts to provide novel systems and methods that overcome at least some of the disadvantages of prior art appliances and methods for providing emergency flotation support for a person or persons in water. Since many such flotation devices are intended for use in emergency only, they are often kept in folded up form, and stowed in storage locations until needed. Such devices include life-saving appliances such as lifeboats or life buoys, which are stored until required in an emergency when they are lowered or thrown into the water. Other such devices are intended to be worn like a jacket or an overall or suit, or another article of clothing, and thus must conform flexibly to the shape of the body of the user and to the movements of the bodies of the user when performing normal activities, including such activities likely to be undertaken in emergency situations, such as running, climbing, wading through water, swimming or diving. In any of these cases, it is important that the inflation device be foldable and flexible. Prior art appliances, because of the often comparatively heavy pressurized gas containers, may not enable the achievement of the above-mentioned desired properties. Even if of acceptable weight, the pressurized gas containers may often have a protruding form, such as a cylinder of sufficient strength to contain the pressurized gas, which interferes with the free actions of the user. The present disclosure describes new exemplary devices, which overcome the limitations of prior art devices, by using a flexible, and hence partially bendable, pressurized gas storage container, in contrast to the gas storage containers of prior art inflatable devices, which are generally that part which prevents achievement of flexibility and foldability. Such a pressurized gas storage container may be in the form of a pneumatic tube, preferably of a plastic material. The feature of such plastic tubes that makes then suitable for this application is that they are generally strong enough to withstand the pressure of the stored gas without rupturing, and yet remain flexible enough, even when pressurized with a gas charge, to enable the folding of the device to the desired shape and size. Such a tube should also be flexible enough not to impede the conformal wearing of the flotation device, or the free movements of the wearer, if part of a wearable flotation device. For the volume of pressurized gas required, as will be discussed in the Detailed Description section hereinbelow, such a tube is generally sufficiently narrow that it can be incorporated into a garment around its edge, and can also serve as a hem strengthener, or it can be located in any other suitable location on the garment. Another novel feature of other implementations of the presently described devices is that a pneumatic pipe used for storage of the high pressure gas, may be used as a part of the structure of a lifeboat or a lifebuoy, such as by also functioning as a safety rope on the flotation device. According to most mandatory regulations, such a safety rope must be supplied on such a life-saving appliance. The rope is intended to be grasped by a person in the water, to ensure easier holding on to the flotation device. One such implementation includes an inflatable lifeboat, in which the pneumatic tube gas container doubles as the mandatorily required holding ropes around the hull of the boat. Similarly, another such an implementation could be a lifebuoy which would be thrown into the water near the person in distress, and which must have a cord attached to it such that the person in the water can readily hold on to the lifebuoy. An alternative flexible pressurized gas container may be in the form of a pouch-like container, which could be built into a wall region within the flexible wall of the flotation device, whether a lifesaving garment or another larger structural lifesaving device, such as a floor section of a lifeboat, or even as part of the inflatable hull of the lifeboat. The pouch could be either a double walled section of the device, or a pouch attached integrally onto the wall section. Such a flexible structural part does not prevent foldability or limit freedom of movement of the user. A characterizing feature of all the flotation devices shown in this disclosure is thus that the pressurized gas container, besides being flexible and foldable, is constructed to be an integral part of the flotation device itself. The pressurized gas will generally be in the form of a liquefied gas, but the term pressurized gas is used throughout this disclosure, in order to contrast to the expanded gas used to inflate the flotation device. In summary, a feature of the devices shown in the present disclosure is the elimination of a separate non-flexible cylinder for holding the pressurized gas, thus enabling the flexible pressurized gas container to be an integral part of the flexible and foldable structure of the flotation device itself. The use in this disclosure of the term "structure" or "structural element" or the like, is intended to include not only the basic construction of the lifesaving flotation device itself, but also any attached accessory which is a mandatory part of the lifesaving flotation device, even if only attached thereto and not built into the device itself. In any of the above described devices, the pressurized gas inside the flexible gas storage container must be passed efficiently and speedily into the flotation chamber, so that the device inflates properly, such that it can support the person or persons in the water. This is achieved by means of a valve which, in order to release the pressurized gas, is actuated by means of a cord or a handle attached to the actuating element of the valve. The valve can be actuated automatically by means of a sensor which determines when the device is in water and then automatically opens the valve after a predetermined time, generally a few seconds or more. Alternatively, the automatic inflation may be activated by the unfolding of the uninflated, stored flotation device. Activation of the valve for such an automatic inflation could be achieved by mechanically associating the activation element of the valve with some element of the unfolding process, such as, for instance, by use of the folded state of the device to maintain the valve actuator element in its unopened position, or for example, by using a cord attached between one of the folds and the actuation lever of the valve. Such an automatic inflation procedure may be unsuitable for a body garment which is intended to be used in a distress situation, since inflation before putting the life-saving garment on, may generate problems to the wearer. This potential problem can be solved by using a sufficiently long delay period following the unfolding action, such that the user can still put on the lifesaving garment before it inflates automatically. Two different types of gases can be used in such inflatable devices, the difference being in their thermodynamic properties. One type of gas, which includes those reported for use in most of the devices in the prior art, use conventional flotation gases such as air or carbon dioxide. Such gases have properties including the need to cool them when at atmospheric pressure, to temperatures substantially below normal ambient temperatures, to turn from gas to a liquid. Such gases then also require very high pressurization to keep them in their liquid phase at ambient temperatures, and even more so at higher temperatures to which they may be exposed in typical summer temperatures in hot climates - typically over 100 bar. Therefore, these gases require a pressurized gas container that withstands such high pressures, and for use in the presently described devices, would require a tube having a thicker wall with more limited flexibility, or for the pouch implementations, thicker walls of the pouch section. A second type of gases, developed for refrigeration and air conditioning applications, such as R1234ze(E) or R1234yf or R1224yd(Z) gases, or other similar gases, have thermodynamic properties with the transition from liquid to gaseous phases occurring at higher temperatures. Consequently, the maximum pressure required to hold the pressurized gas even at temperatures of up to 70°C, is still only of the order of 20 bar. Besides the obvious advantage of requiring a flexible tube of lower wall thickness, and hence greater flexibility than that of the first type of gas, or, in the case of the pouch embodiments, thinned walls, there is another advantage of the gases of this second type, in that they have significantly larger molecules than the previously used conventional gases such as air or CO2. One dominant feature related to molecular size is the diffusability of the gas molecules through the wall of any vessel with which that are in contact. The larger the molecule size, the lower the level of diffusion through any boundary wall containing the gas. This feature has ramifications both with regard to the ability of the pressurized gas container to maintain its charge over long periods of time, thereby affecting the shelf life of the flotation device, and furthermore, with regard to the length of time the inflation balloon will maintain its gas fill and support the user, before diffusion out of the inflation balloon lowers the gas fill so much that the device can no longer provide the support that was originally expected. It is to be understood that the terms flexible and foldable are intended to mean that all, or almost all, of the relevant parts of the flotation device are flexible and can be folded flat, in order to distinguish from a flotation device which includes, for instance, a pressurized gas container in the form of a cylinder or another three dimensional solid vessel. Such a flotation device could also be called "flexible" or "foldable" in that the device could be bent or folded, except for the protrusion of the pressurized gas container. The terms flexible and foldable, as used in the present disclosure, are intended to describe a device where both the pressurized gas container, and the inflation element are flexible and can be folded essentially flat, where the term essentially is to be understood to mean that no solid protrusions which would limit the flatness of the folded device, or the ease of storage of the folded device, for instance when stacked or in a pile. This feature should also be evident from the advantage of the described devices, that they do not have bulky or protruding pressurized gas containers, that may also impede movements. The inflation valve, though not necessarily foldable, may be sufficiently narrow that it does not impede the flexibility of the device. There is thus provided in accordance with an exemplary implementation of the devices described in this disclosure, a flexible lifesaving device, comprising: (i) an internal space adapted to inflate when filled with a gas, the volume of the space being sufficient when inflated, to provide flotation in water to at least one person when using the device, having up to a predetermined total weight; (ii) a flexible container, integral to the device, comprising either a length of tubing or a pouch section of a wall of the device, the container being adapted to hold a volume of pressurized flotation gas sufficient, when it is in the gaseous phase, to inflate the internal space; and (iii) a valve connecting the flexible container with the internal space of the device, such that when the valve is opened, the volume of pressurized flotation gas flows into the internal space, thereby providing flotation to the device, wherein the flexible container is part of the essential structure of the flexible life-saving device. There is further provided in accordance with another exemplary implementation of the devices described in this disclosure, a lifeboat comprising: (i) a foldable inflatable hull and a floor element, the foldable inflatable hull having an internal volume adapted to be inflated with a gas, (ii) a flexible pressurized gas container adapted to contain a volume of pressurized flotation gas sufficient, when in its gaseous phase, to inflate the hull of the lifeboat such that the lifeboat can float on water while carrying a predetermined number of persons, and (iii) a valve connecting the flexible pressurized gas container with the internal volume of the foldable inflatable hull, such that when the valve is opened, the volume of pressurized flotation gas flows into the internal volume of the hull, thereby providing flotation to the lifeboat, wherein at least a part of the flexible pressurized gas container is a structural element of the lifeboat. In such a lifeboat, the pressurized gas container may be at least one of (i) at least a section of the floor element and (ii) at least a section of the inflatable hull. Such a pressurized gas container may have the form of a pouch for containing the pressurized gas. Additionally, the flexible pressurized gas container may be a length of tubing. Such a length of tubing may be mounted on the lifeboat in a position that enables at least a part of it to be used as a gripping rope of the lifeboat. The flexibility of the length of tubing when containing the volume of pressurized flotation gas, should be such that the inflatable lifeboat has a predetermined flexibility. Furthermore, the flexibility of the length of tubing adapted to contain the pressurized flotation gas should be such that when the lifeboat is uninflated, it is foldable to an essentially flat form. There is further provided, in accordance with yet another exemplary implementation of the devices described in this disclosure, a personal lifesaving attire, comprising: (i) a flexible garment, at least part of the area of the garment having a double wall generating a hollow space adapted to inflate when filled with a gas, the volume of the space being sufficient when inflated, to provide flotation in water to a person wearing the garment, having up to a predetermined weight, (ii) a flexible container comprising either a length of tubing or a pouch section of the garment, adapted to hold a volume of pressurized flotation gas sufficient, when it is in the gaseous phase, to inflate the hollow space, and (iii) a valve connecting the flexible container with the hollow space of the garment, such that when the valve is opened, the volume of pressurized flotation gas flows into the hollow space, thereby providing flotation to the garment, wherein the flexible container is part of the garment. The attire could be any one of a life vest, a pilot’s suit, or a swim suit. In such a personal lifesaving attire, the flexible tubing may be attached to the edges of the material of the garment. Furthermore, the flexibility of the length of flexible tubing when containing the volume of pressurized flotation gas, should be such that the attire has a predetermined level of flexibility. This flexibility should be such as to enable the attire to be foldable to an essentially flat form. There is even further provided, in accordance with another exemplary implementation of the devices described in this disclosure, an inflatable lifebuoy, comprising: (i) an inflatable body having an internal volume such that when inflated with a gas, the inflated body can float on water while supporting a person having up to a predetermined weight, (ii) a length of flexible tubing adapted to hold pressurized flotation gas, sufficient in its gaseous phase to inflate the body of the lifebuoy, and (iii) a valve connecting the flexible tubing with the internal volume of the inflatable body, such that when the valve is opened, the volume of released gas flows into the internal volume of the inflatable body, thereby providing flotation to the body. In such an inflatable lifebuoy, the flexible tubing should be mounted on the periphery of the lifebuoy in a manner that enables at least a part of it to comprise a holding cord of the lifebuoy. Additionally, the flexibility of the length of flexible tubing when containing the pressurized flotation gas should be such that the inflatable lifebuoy has a predetermined flexibility. This level of flexibility of the length of flexible tubing should be sufficiently high that when uninflated, the inflatable lifebuoy is foldable to an essentially flat form. According to yet further implementations of any of the lifesaving devices mentioned above, the inflation gas may have thermodynamic properties such that when compressed to a pressure of not more than 10 bar, it remains in a liquid phase over a range of temperatures of up to 50°C. Alternatively, when compressed to a pressure of not more than 14 bar, it remains in a liquid phase over a range of temperatures of up to 70°C. Even further alternatively, when compressed to a pressure of not more than 22 bar, it remains in a liquid phase over a range of temperatures of up to 70°C. Additionally, in any of the lifesaving devices mentioned above. the valve may be activated manually, or it may be activated automatically when in contact with water. As another alternative, it may be activated automatically when the lifesaving device is unfolded to a predetermined state from a stored condition.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be understood and appreciated more fully from the following detailed description, taken in conjunction with the drawings in which: Fig.1A to Fig. 1C show schematic representations of three different types of flotation appliances or devices, according to different exemplary implementations described in the present disclosure; Fig. 2A shows an implementation of the flotation devices shown schematically in Fig. 1A, in the form of a garment for the upper part of the body having a flexible tube around at least part of its outer edges, while Fig. 2B shows a cross section of a similar garment, but using an integral pouch to contain the pressurized gas; Fig. 3 shows an implementation of the flotation devices shown schematically in Fig. 1B, in the form of a garment for the lower part of the body; Fig. 4 shows an implementation of the flotation devices shown schematically in Fig. 1C, in the form of a lifeboat; and Fig. 5 shows an implementation of the flotation devices shown schematically in Fig. 1C, in the form of a lifebuoy. DETAILED DESCRIPTION Reference is first made to Figs. 1A to 1C, which illustrate schematically, three different types of appliance or device 10, according to different exemplary implementations of the devices described in the present disclosure, using three different operational structures. All of the devices have the intended object of providing emergency flotation when required to a user or wearer of the device, when in a body of water. Each of the exemplary implementations comprises three common features which are adapted to achieve this intended object, the three features being: (i) a storage volume 12 for containing the compressed gas for providing inflation to - (ii) a flotation balloon 11, attached to, or an integral part of the device 10, and (iii) a valve arrangement 13 intended to activate the device by enabling the stored gas in the gas storage vessel 12 to flow into the inflation balloon 11, and to expand as a gas to provide inflation to the flotation balloon 11, and hence to the entire device 10 and its wearer or user. Although the three embodiments shown in Figs. 1A, 1B and 1C have different forms, the above three generic elements are found in each of them, and have therefore been given the same item number in the three embodiments. In all of Figs. 1A to 1C, the elements are shown in a very schematic form to show the inventive nature of the devices, without any intention of showing the actual form of the device claimed. Thus, the flotation device itself 10, is shown as a plain rectangle, even though it could take any shape, such as those examples described more fully hereinbelow, or any other desired shape. Likewise, the flotation balloon 11 is shown shaped like a balloon, even if it could take a number of other shapes, according to the intended use of the device. Fig. 1A shows a first schematic embodiment of the devices of the present disclosure, in which a pneumatic tube is used as the storage container of the pressurized gas. The tube is installed as an integral part of the flotation device 10, and is shown located around the peripheral edge of the flotation device, which is an advantageous position since that position does not generally interfere with the other functionalities of the device.. Fig. 1B shows a second schematic embodiment of the devices of the present disclosure, in which the storage container of the pressurized gas is in the form of a pouch-like container 15, most simply constructed as a double wall section in the wall of flotation device 10. Fig. 1C shows a third schematic embodiment of the devices of the present disclosure, in which the storage container of the pressurized gas is a pneumatic tube, as in Fig. 1A, but in Fig. 1C, the pneumatic tube is installed in a spatial situation such that at least a part of the pneumatic tube 12 extends outside of the peripheral edge of the flotation device 10. The common feature of all of the three different implementations shown in Figs. 1A to 1C, and of any others like those shown, is that the entire flotation device 10, including the pressurized gas container 12, whether a suitable pneumatic tube 12, or a pouch 15, is flexible, so that the device can be folded for stowage before use. Furthermore, when in use, if the device is intended to be worn, it can conform to the body’s shape without significantly impeding the freedom of movement of the wearer or user.

Reference is now made to Fig. 2A, which shows a schematic drawing of a first implementation of the flotation devices shown schematically in Fig. 1A. The flotation device is shown in the form of a garment 20 for the upper body-part of the user, which is intended to be an exemplary representation of any upper garment, such that it could be a life vest, such as is used in a passenger aircraft, or a pilot suit, such as would be used in a combat aircraft, or a sailor’s lifejacket, or any other similar garment. The inflatable balloon 21 is shown in the chest area of the garment, though it is to be understood that it could be located anywhere within the garment. The pressurized gas container is shown as a flexible hose 22, which can advantageously and conveniently formed around at least part of the edge of the garment. The gas charge is released into the inflatable balloon section, by means of a release valve 23, which can be operated by the wearer of the safety garment, or can be automatically actuated such as by means of a sensor which determines when the safety jacket is in contact with water. For an average sized user, an inflatable balloon volume of approximately 5.5 liters of expanded gas is required, and assuming an expansion ratio of 250 in going from the liquid phase to the gaseous phase of the gas, the volume of liquefied gas required is 22 ml. Thus, for a flexible plastic tube having a 3 mm internal diameter, the length of tubing required to hold the 22ml. volume of gas will be slightly more than 300cm, which is a length that can be conveniently distributed over the peripheral regions of the garment. A 3mm. ID polyurethane tube, is convenient to use in this application, because of its level of flexibility, making it suitable for use in the wearable flotation devices, such as that shown in Fig. 2. Such a polyurethane tube with a 1mm. wall thickness, is able to withstand a 10 bar internal pressure over a working temperature of -40°C and 90°C, while still maintaining acceptable flexibility. However, the suggestion to use polyurethane tubing is not intended to be limiting, and any suitably flexible pipe, which can withstand the internal pressure requirements over a desired pressure range, could the acceptably used. A filling opening (not shown in the drawings) is also required in such a flexible pipe gas charge container, or the flexible pipe may be pre-charged and sealed during manufacture of the device. Reference is now made to Fig. 2B, which shows a schematic drawing of another implementation of the flotation devices, as shown schematically in Fig. 1B. Fig. 2B, shows an exemplary cut away drawing of an upper garment 25 showing a sleeve 29, similar to that of Fig. 2A, implemented using a conformal pouch-like space 26 to contain the pressurized gas instead of the flexible tube of Fig. 2A. The pouch-like gas container 26 may be simply implemented by using an impermeable double-walled section of the fabric of the flotation device 25 as the pressurized gas container. The pneumatic connection between the pressurized gas-storing pouch 26 and the inflatable balloon section 27 of the wearable flotation device, is, as previously described, implemented through an actuation valve 28, which could be set in the plane of the fabric of the garment. The drawing of Fig. 2B shows the inflatable balloon section 27 in its uninflated state, before opening of the actuation valve 28. Furthermore, the drawing of Fig. 2B shows only a single cut-away plane of the garment, but it is to be understood that the pouch and the inflation balloon section 27 could extend around part or all of the circumference of the garment 25. Reference is now made to Fig. 3, which shows a second implementation of the flotation devices shown schematically in Fig. 1A. This flotation device is shown in the form of a pair of pants 30, which is intended to be an exemplary representation of any garment for the lower part of the body, and shows the inflatable balloon 31, the flexible tube 32 filled with the pressurized gas charge, and the activating valve 33. In such a garment for the lower part of the body, the inflatable balloon 31 should be positioned in the upper part of the garment, close to the waist, in order to reduce the possibility that flotation forces applied from lower down on the body may result in the unwanted effect of turning the wearer upside-down. The calculations of the total tube length are similar to those shown in Fig. 2A. A combination of the embodiments of Fig, 2A or 2B and Fig 3 could be used to describe the implementation of the flotation devices of this disclosure, in a full body garment, such as a pilot’s suit. The term "garment" is thus intended in this disclosure, to be used, and is thuswise claimed, as a generic term to include any article worn by the user, in which flotation mechanisms of the present disclosure may be incorporated. Reference is now made to Fig. 4, which now shows an implementation of the flotation devices shown schematically in Fig. 1C. Fig. 4 shows an inflatable lifeboat 40 as an example of such a life-saving flotation device. The inflatable balloon is the inflatable body 41 of the lifeboat itself, with the lifeboat floor 45, stretched between the walls of the body 41. One feature of the lifeboat embodiments of the flotation devices of the present application, is that the regulatory mandated gripping rope around the body of the lifeboat, is implemented by a length of flexible tubing 42, which itself acts as the pressurized gas container for inflation of the inflatable body 41 of the lifeboat, that inflation being activated by means of the activating valve 43 located in an accessible position on the lifeboat. As described previously, the activation valve 43 could be either manually operated, or it could be automatically activated on contact with water. Such automatic valves are available in narrow dimensioned forms, which though not flexible, can be located in regions of the lifeboat where they do not degrade the flexibility of the remainder of the lifeboat component parts. Some such automatic valves can be supplied by Survitec Ltd., of London, UK. In the drawing of Fig. 4, the pressurized gas container/gripping rope is shown only along the outer wall of the lifeboat, but it is to be understood that it can also be deployed along a bulkhead shelf facing a seat in the lifeboat, as is required in lifeboats intended to carry more than a small number of persons, depending on the relevant regulation. Because of the larger volume of inflation gas required in the lifeboat implementation of the present invention, a larger diameter flexible pneumatic hose is more suitable than that of the above described inflatable garments. A flexible hose having an outside diameter of up to 2 cm may be required for large lifeboats, such a sized hose still having sufficient flexibility that the lifeboat can be folded and stored in its predetermined location on the mother vessel. To illustrate the dimensions and length of the flexible hose required, an example of the volume of expanded gas required for inflating a small lifeboat capable of carrying a small number of persons, is of the order of up to 500 liters, such that using an expansion ratio from the liquid phase to the gaseous phase of 250, the volume of liquefied gas required is of the order of 2 liters. For a 2 cm ID hose, in order to hold a liquid pressurized gas charge generating 500 liters of gaseous phase gas, a length of hose of the order of 6 m. would be required, which is a suitable length for use as a gripping rope around the body of a lifeboat of that size. As an alternative to the length of flexible tubing 42 described above, the pressurized gas container may alternatively be implemented by any other suitable part of the lifeboat, on condition that it does not limit the flexibility or foldability of the complete lifeboat. One such suitable structure could be one or more double walled sections of the lifeboat floor 45, in the form of a pouch, which could withstand the pressure of the pressurized gas load. Though not shown in Fig. 4, the construction of such a pouch-type pressurized gas container could be similar to that shown as item 26 in the inflatable garment embodiment of Fig. 2B. Such a pouch, like the previously described flexible tube, would be an integral part of the lifeboat structure, and, being flexible, need not significantly impede the flexibility and foldability of the lifeboat before inflation. Reference is now made to Fig. 5, which shows an additional exemplary implementation of the flotation devices shown schematically in Fig. 1C, in this example, as an inflatable lifebuoy. Previously known lifebuoys are generally solid rings, constructed of a lightweight material such as expanded polystyrene or a similar material, to provide the flotation forces for the lifebuoy, with a tough weather and scuff-resistant outer covering. According to the implementation of the present flotation devices, an inflatable lifebuoy is proposed, which, by using the design concepts of the present disclosure as illustrated in Fig. 1C, has the advantage of being flexible and hence foldable, thereby occupying substantially less space than prior art solid lifebuoys. In Fig. 5, the lifebuoy 50, shown in its inflated form, has a gas fillable body 51, acting as the inflatable balloon of the present disclosure. A lifebuoy has to have a gripping rope firmly affixed thereto, and this is achieved in the device of Fig. 5 by using the pressurized gas container 52 in the form of a flexible tube, whose primary function is to contain the pressurized gas for inflation of the inflatable body 51 of the lifebuoy. The flexible tube acting also as the grasping cord, should be fixed to the body of the lifebuoy at several fixing anchors 55, around the periphery of the lifebuoy. The inflation is activated by means of an activating valve located in an accessible position on the lifebuoy, such that it can be actuated to enable the released gas to inflate the lifebuoy either by the deployer before throwing the lifebuoy into the water to assist a person in the water, or by the user him/herself before leaving a distressed vessel and jumping into the water. The actuation of the inflation valve can be either manual, by means of a handle or cord, or automatic by contact with the water, as described hereinabove. All of the above described flotation devices can use any of the conventional gases described in the prior art, whether carbon dioxide or air, as were used in the earliest flotation devices, or refrigeration gases such as a mixture of 89% Freon 12 with 11% Propane, as used more recently, and such as is described in WO 83/04234, or the even more modern inflation gas fills such as the R1234ze(E) or R1234yf or R1224yd(Z) gases as described in the above-mentioned WO 2020/208636 publication. However, as is explained fully in WO 2020/208636, the early used gases like CO2 or air, had to be compressed to a very high pressure of the order of 80 Bar at normal ambient temperatures to get them into their liquid phases, which rises to a pressure of 150 Bar at a temperature of 45°C. In the prior art flotation devices, these high pressures mandated the use of a sturdy gas container with all of its concomitant disadvantages. When used on the flotation devices of the present application, that requirement would be translated into the need for a flexible tube or a pouch section having a thicker wall, to withstand the high pressures of such pressurized gases, and hence being less flexible. On the other hand, the pressure of a compressed charge of the above mentioned newer gases, does typically not exceed bar at a temperature of 50°C, or about 16 bar at a temperature of 70°C. The wall thickness of flexible hose used to store the pressurized inflation gas would need to be significantly larger using the earlier conventional gases, than the tube wall thickness for those same embodiments using the more recent above mentioned inflation gases, operating at significantly lower pressures. The flexibility and foldability obtained using the low pressure gases would be less than that using the more modern gases mentioned above. The thinner the walls of the pneumatic hosing, the more flexible is the hose, and hence, the more useful for the various flexible and foldable flotation devices, as described hereinabove. An additional advantage of the use of the more modern, "low operating pressure" gases, such as the above mentioned R1234ze(E) or R1234yf or R1224yd(Z) gases, or other gases having similar thermodynamic properties, is that those gases have larger molecules than the originally used air or CO2 gases. One dominant feature related to molecular size is the diffusability of the gas molecules through the wall of any vessel with which that are in contact. The larger the molecule size, the lower the level of diffusion through any boundary wall containing the gas. This feature has ramifications in two respects. Firstly, with regard to the ability of the pressurized gas container to maintain its charge over long periods of time, thereby affecting the shelf life of the flotation device. Secondly, with regard to the length of time the inflation balloon will maintain its gas fill and support the user, before diffusion out of the inflation balloon lowers the gas fill so much that the device can no longer provide the support that was originally provided. It would thus appear that the use of "low pressure gases", namely those that maintain their liquid phase out to temperatures such as 50°C or 70°C, substantially higher than ambient temperatures, would enable the flotation device to have significantly improved performance, both in lifetime and in performance, over the use of simpler, and higher pressure gases.

Example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. Furthermore, it is appreciated by persons skilled in the art that the present invention is not limited by what has been particularly shown and described hereinabove. Rather the scope of the present invention includes both combinations and subcombinations of various features described hereinabove as well as variations and modifications thereto which would occur to a person of skill in the art upon reading the above description and which are not in the prior art.

Claims

1.CLAIMS We claim: 1. A lifeboat comprising: a foldable inflatable hull and a floor element, the foldable inflatable hull having an internal volume adapted to be inflated with a gas; a flexible pressurized gas container adapted to contain a volume of pressurized flotation gas sufficient, when in its gaseous phase, to inflate the hull of the lifeboat such that the lifeboat can float on water while carrying a predetermined number of persons; and a valve connecting the flexible pressurized gas container with the internal volume of the foldable inflatable hull, such that when the valve is opened, the volume of pressurized flotation gas flows into the internal volume of the hull, thereby providing flotation to the lifeboat, wherein at least a part of the flexible pressurized gas container is an essential structural element of the lifeboat.

2. A lifeboat according to claim 1 wherein the flexible pressurized gas container of the lifeboat is at least one of (i) at least a section of the floor element and (ii) at least a section of the inflatable hull.

3. A lifeboat according to either of claims 1 and 2, wherein the flexible pressurized gas container is a length of tubing.

4. A lifeboat according to claim 3 wherein, the length of tubing is mounted on the lifeboat in a position that enables at least a part of it to be used as a gripping rope of the lifeboat.

5. A lifeboat according to claim 2, wherein the at least a section of the floor element of the lifeboat has the form of a pouch for containing the pressurized gas.

6. A lifeboat according to claim 3 wherein the flexibility of the length of tubing when containing the volume of pressurized flotation gas, is such that the inflatable lifeboat has a predetermined flexibility.

7. A lifeboat according to claim 3 wherein the flexibility of the length of tubing adapted to contain the pressurized flotation gas is such that when the lifeboat is uninflated, it is foldable to an essentially flat form.

8. A lifeboat according to any of the previous claims, wherein the inflation gas has thermodynamic properties such that when compressed to a pressure of not more than 10 bar, it remains in a liquid phase over a range of temperatures of up to 50°C.

9. A lifeboat according to any of claims 1 to 7, wherein the inflation gas has thermodynamic properties such that when compressed to a pressure of not more than 14 bar, it remains in a liquid phase over a range of temperatures of up to 70°C.

10. A lifeboat according to any of claims 1 to 7, wherein the inflation gas has thermodynamic properties such that when compressed to a pressure of not more than 22 bar, it remains in a liquid phase over a range of temperatures of up to 70°C.

11. A lifeboat according to any of the previous claims, wherein the valve is activated manually.

12. A lifeboat according to any of claims 1 to 10, wherein the valve is activated automatically when in contact with water.

13. A lifeboat according to any of claims 1 to 10, wherein the valve is activated automatically when the inflatable lifeboat is unfolded to a predetermined state from a stored condition.

14. A personal lifesaving attire, comprising: a flexible garment, at least part of the area of the garment having a double wall generating a hollow space adapted to inflate when filled with a gas, the volume of the space being sufficient when inflated, to provide flotation in water to a person wearing the garment, having up to a predetermined weight; a flexible container comprising either a length of tubing or a pouch section of the garment, adapted to hold a volume of pressurized flotation gas sufficient, when it is in the gaseous phase, to inflate the hollow space; and a valve connecting the flexible container with the hollow space of the garment, such that when the valve is opened, the volume of pressurized flotation gas flows into the hollow space, thereby providing flotation to the garment, wherein the flexible container is part of the garment.

15.A personal lifesaving attire according to claim 14, wherein the flexible tubing is attached to the edges of the material of the garment.

16. A personal lifesaving attire according to either of claims 14 or 15, wherein the garment is any one of a life vest, a pilot’s suit, or a swim suit.

17. A personal lifesaving attire according to any of claims 14 to 16, wherein the flexibility of the length of flexible tubing when containing the volume of pressurized flotation gas, is such that the attire has a predetermined flexibility.

18. A personal lifesaving attire according to any of claims 14 to 17, wherein the flexibility of the length of flexible tubing adapted to contain the pressurized flotation gas enables the attire to be foldable to an essentially flat form.

19.A personal lifesaving attire according to any of claims 14 to 18, wherein the inflation gas has thermodynamic properties such that when compressed to a pressure of not more than bar, it remains in a liquid phase over a range of temperatures of up to 50°C.

20. A personal lifesaving attire according to any of claims 14 to 18, wherein the inflation gas has thermodynamic properties such that when compressed to a pressure of not more than bar, it remains in a liquid phase over a range of temperatures of up to 70°C.

21. A personal lifesaving attire according to any of claims 14 to 18, wherein the inflation gas has thermodynamic properties such that when compressed to a pressure of not more than bar, it remains in a liquid phase over a range of temperatures of up to 70°C.

22. A personal lifesaving attire according to any of claims 14 to 21, wherein the valve is activated manually.

23. A personal lifesaving attire according to any of claims 14 to 21, wherein the valve is activated automatically when in contact with water.

24. An inflatable lifebuoy, comprising: an inflatable body having an internal volume such that when inflated with a gas, the inflated body can float on water while supporting a person having up to a predetermined weight; a length of flexible tubing adapted to hold pressurized flotation gas, sufficient in its gaseous phase to inflate the body of the lifebuoy; and a valve connecting the flexible tubing with the internal volume of the inflatable body, such that when the valve is opened, the volume of released gas flows into the internal volume of the inflatable body, thereby providing flotation to the body.

25. An inflatable lifebuoy according to claim 24, wherein the flexible tubing is mounted on the periphery of the lifebuoy in a manner that enables at least a part of it to comprise a holding cord of the lifebuoy.

26. An inflatable lifebuoy according to either of claims 24 and 25, wherein the flexibility of the length of flexible tubing when containing the pressurized flotation gas is such that the inflatable lifebuoy has a predetermined flexibility.

27. An inflatable lifebuoy according to either of claims 24 and 25, wherein the flexibility of the length of flexible tubing adapted to contain the pressurized flotation gas is sufficiently high that when uninflated, the inflatable lifebuoy is foldable to an essentially flat form.

28. An inflatable lifebuoy according to any of claims 24 to 27, wherein the inflation gas has thermodynamic properties such that when compressed to a pressure of not more than bar, it remains in a liquid phase over a range of temperatures of up to 50°C.

29. An inflatable lifebuoy according to any of claims 24 to 27, wherein the inflation gas has thermodynamic properties such that when compressed to a pressure of not more than bar, it remains in a liquid phase over a range of temperatures of up to 70°C.

30. An inflatable lifebuoy according to any of claims 24 to 27, wherein the inflation gas has thermodynamic properties such that when compressed to a pressure of not more than bar, it remains in a liquid phase over a range of temperatures of up to 70°C.

31. An inflatable lifebuoy according to any of claims 24 to 30, wherein the valve is activated manually.

32. An inflatable lifebuoy according to any of claims 24 to 30, wherein the valve is activated automatically when in contact with water.