Emergency flotation device using compressed gas

Abstract

A flotation device for providing emergency flotation for a person swimming or passing through a body of water, comprising a container filled with a charge of a gaseous material under a pressure such that it is in its liquid phase at normal environmental temperatures. The container is connected to a flexible flotation chamber through a passage which remains normally closed until actuated by the user. When the device is actuated by opening the passage, the charge expands into the flotation chamber, thereby inflating it, and providing support to the user in the water. The gaseous material has thermodynamic properties such that it remains in its liquid phase right up to the maximum temperatures to which the device is expected to be exposed to. Consequently, its volume, and hence the internal pressure within the gas container, does not increase significantly, thereby enabling the container to be of lightweight construction.

1 . A flotation device comprising:
 a container adapted to hold a charge of a pressurized gaseous material having thermodynamic properties such that when compressed into the container at a pressure of not more than 10 bar, it remains in a liquid phase over a range of temperatures of up to 50° C.; and   a flexible flotation chamber communicating with the compressed gas container through a passage, the passage remaining normally closed until its opening is actuated, thereby   allowing the charge to expand into the flotation chamber, and to inflate the flotation chamber.   
     
     
         2 . A flotation device according to  claim 1 , wherein the gaseous material has thermodynamic properties such that when compressed into the container at a pressure of not more than 14 bar, it remains in a liquid phase over a range of temperatures of up to 70° C. 
     
     
         3 . (canceled) 
     
     
         4 . A flotation device according to  claim 1 , wherein the flotation device is adapted to be manually activated by a user. 
     
     
         5 . A flotation device according to  claim 1 , wherein the flotation device is adapted to be activated automatically, independently of the user. 
     
     
         6 . A flotation device according to  claim 1 , wherein the passage comprises a valve. 
     
     
         7 . A flotation device according to  claim 1 , wherein the passage is closed by a stopper, which is adapted to be released when the device is activated. 
     
     
         8 . A flotation device according to  claim 1 , wherein the container occupies a volume of less than 80 milliliters and the charge of gaseous material expands to at least 5 liters when released into the flexible flotation chamber. 
     
     
         9 . A flotation device according to  claim 1 , wherein the pressurized charge of gaseous material in its liquid phase expands by less than 12% over a range of temperatures of from 15° C. to 50° C. 
     
     
         10 . A flotation device according to  claim 1 , wherein the pressurized charge of gaseous material in its liquid phase expands by less than 15% over a range of temperatures of from 15° C. to 70° C. 
     
     
         11 . A flotation device according to  claim 5 , further comprising a sensor indicative of immersion in water for more than a predetermined time, and providing a signal to activate the inflation device. 
     
     
         12 . A flotation device according to  claim 5 , further comprising a sensor adapted to detect any one of vibration, depth, pressure or light. 
     
     
         13 . A flotation device according to  claim 1 , wherein the gaseous material comprises a Tetrafluoropropene-based hydrofluoroolefin. 
     
     
         14 . A flotation device according to  claim 1 , wherein the gaseous material comprises R1234ze(E) or R1234yf. 
     
     
         15 - 16 . (canceled) 
     
     
         17 . A flotation device according to  claim 1 , wherein the device has a strap configured to enable the device to be worn on any of the wrist, arm, waist, chest or neck of a user. 
     
     
         18 - 24 . (canceled) 
     
     
         25 . A flotation device according to  claim 1 , wherein the container has walls constructed of a polymer material of less than 2.5 mm in thickness. 
     
     
         26 . A method of maintaining the safety of a flotation device, the flotation device comprising:
 a container adapted to hold a charge of a pressurized gaseous material, and adapted to withstand a pressure of 10 bar;   a flexible flotation chamber communicating with the compressed gas container through a passage, the passage remaining normally closed until its opening is actuated; and   a mechanism adapted to actuate opening of the passage to allow the charge to expand into the flotation chamber, thereby inflating the flotation chamber;   the method comprising selecting the gaseous material to have thermodynamic properties such that when compressed into the container at a pressure of not more than 10 bar, it remains in a liquid phase at temperatures of up to 50° C., such that the device maintains its safety at temperatures of up to 50° C.   
     
     
         27 . A method according to  claim 26 , wherein the gaseous material further has thermodynamic properties such that when compressed into the container at a pressure of not more than 14 bar, it remains in a liquid phase at temperatures of up to 70° C., such that the device maintains its safety at temperatures of up to 70° C. 
     
     
         28 . A flotation device comprising:
 a container adapted to hold a charge of a pressurized gaseous material, the pressurized gaseous material being confined in the container by a stopper in an opening in a wall of the container, the stopper being held in place by a facing member to which the container is attached, with a force such that the container is separable from the facing member by hand operation; and   a flexible flotation chamber in fluid communication with the stoppered opening of the container,   wherein the stopper is held in the opening with a force such that when the container is separated from the facing member, a pressure of no more than 14 bar of the gaseous material in the container is sufficient to eject the stopper to enable the pressurized gaseous material to inflate the flexible flotation chamber.   
     
     
         29 . A flotation device according to  claim 28 , wherein the stopper is held in the opening with a force such that when the container is separated from the facing member, a pressure of no more than 10 bar of the gaseous material in the container is sufficient to eject the stopper to enable the pressurized gaseous material to inflate the flexible flotation chamber. 
     
     
         30 . A flotation device according to  claim 28 , wherein the container has walls constructed of a polymer material of less than 2.5 mm in thickness.