Buoyancy device

Abstract

A buoyancy device ( 1 ) is attached to a structure to be floated or sunk. The buoyancy device ( 1 ) comprises a restriction device such as a rigid tube ( 3 ) and an inflatable member ( 5, 15 ) located within the restriction device ( 3 ). The restriction device ( 3 ) restricts inflation of the inflatable member ( 5, 15 ). The inflatable member ( 5, 15 ) comprises a first flexible portion ( 5 ) and may be in the form of a tube ( 5 ) and a second flexible portion ( 15 ) which may be in the form of a diaphragm ( 15 ). The tube ( 5 ) is coupled to the restriction device ( 3 ) and the diaphragm ( 15 ) is coupled to the tube ( 5 ).

1 . A buoyancy device ( 1 ) for attachment to a structure to be floated or sunk, the buoyancy device ( 1 ) comprising a restriction device ( 3 ) and an inflatable member ( 5 ,  15 ) located substantially within the restriction device ( 3 ), such that the restriction device ( 3 ) restricts inflation of the inflatable member ( 5 ,  15 ), characterised in that the inflatable member ( 5 ,  15 ) comprises a first ( 5 ) and second ( 15 ) flexible portions, the first portion ( 5 ) being coupled to the restriction device ( 3 ) and the second portion ( 15 ) being coupled to the first portion ( 5 ).  
     
     
         2 . A buoyancy device ( 1 ) according to  claim 1 , wherein the second portion ( 15 ) comprises a diaphragm ( 15 ).  
     
     
         3 . A buoyancy device ( 1 ) according to either  claim 1  or  2 , wherein the first portion ( 5 ) comprises a cylindrical bag ( 5 ).  
     
     
         4 . A buoyancy device ( 1 ) according to  claim 3 , wherein the cylindrical bag ( 5 ) is open ended at both ends ( 5 A,  5 B).  
     
     
         5 . A buoyancy device ( 1 ) according to  claim 4 , wherein the cylindrical bag ( 5 ) is coupled to the restriction device ( 3 ) at both of its ends( 5 A,  5 B).  
     
     
         6 . A buoyancy device ( 1 ) according to any preceding  claim 1 , wherein the restriction device ( 3 ) permits the ingress and/or egress of fluid from within the buoyancy device ( 1 ).  
     
     
         7 . A buoyancy device ( 1 ) according to any preceding  claim 1 , wherein the restriction device ( 3 ) has at least one aperture ( 9 B,  14 B) to permit fluid to flow therethrough.  
     
     
         8 . A buoyancy device ( 1 ) according to any preceding  claim 1 , wherein the buoyancy device ( 1 ) is arranged such that water located outwith the restriction device ( 3 ) can enter at least a portion of the restriction device ( 3 ) and act upon a surface of the first ( 5 ) and second portions ( 15 ).  
     
     
         9 . A buoyancy device ( 1 ) according to any preceding  claim 1 , wherein the restriction device ( 3 ) is substantially tubular.  
     
     
         10 . A buoyancy device ( 1 ) according to  claim 9 , wherein the restriction device ( 3 ) is open ended at both ends ( 3 A,  3 B).  
     
     
         11 . A buoyancy device ( 1 ) according to  claim 10 , wherein one end ( 5 A) of the first portion ( 5 ) is secured to one end ( 3 A) of the restriction device ( 3 ), and the other end ( 5 B) of the first portion ( 5 ) is secured to the other end ( 3 B) of the restriction device ( 3 ).  
     
     
         12 . A buoyancy device ( 1 ) according to  claim 11 , wherein the said one end ( 5 A) of the first portion ( 5 ) is coupled to a first fluid inlet and/or outlet port ( 7 A,  14 A).  
     
     
         13 . A buoyancy device ( 1 ) according to either of claims  11  or  12 , wherein the said other end ( 5 B) of the first portion ( 5 ) is coupled to a second fluid inlet and/or outlet port ( 7 B,  14 B).  
     
     
         14 . A buoyancy device ( 1 ) according to  claim 13 , wherein the second fluid inlet and/or outlet port ( 7 B,  14 B) permits water from outwith the buoyancy device ( 1 ) to pass into the buoyancy device ( 1 ).  
     
     
         15 . A buoyancy device ( 1 ) according to any preceding  claim 1 , wherein the first ( 5 ) and second ( 15 ) portions are formed from a substantially flexible material, and the restriction device ( 3 ) is formed from a rigid material.  
     
     
         16 . A buoyancy device ( 1 ) according to any preceding  claim 1 , wherein an end of the second portion ( 15 ) is secured to the first portion ( 5 ) at substantially the mid-point of the interior of the first portion ( 5 ).  
     
     
         17 . A buoyancy device ( 1 ) according to  claim 12 , or to any of  claims 13  to  16  when dependent upon  claim 12 , wherein one face of the second portion ( 15 ) is in fluid communication with the first fluid inlet and/or outlet port ( 7 A,  14 A).  
     
     
         18 . A buoyancy device ( 1 ) according to  claim 17 , wherein another face of the second portion ( 15 ) is in fluid communication with the second fluid inlet and/or outlet port ( 7 B,  14 B).  
     
     
         19 . A buoyancy device ( 1 ) according to any preceding  claim 1 , wherein the first portion ( 5 ) is secured to the second portion ( 15 ) by welding and the first portion ( 5 ) is secured to the restriction device ( 3 ) by means of a pair of annular rings ( 7 A,  7 B).  
     
     
         20 . A buoyancy device ( 1 ) according to  claim 19 , wherein the pair of annular rings ( 7 A,  7 B) comprise bores ( 14 A,  14 B) to provide the first ( 7 A,  14 A) and second fluid inlet and/or outlet ports ( 7 B,  14 B).  
     
     
         21 . A buoyancy device ( 1 ) according to any preceding  claim 1 , wherein the first portion ( 5 ) is substantially tubular when inflated, and the second portion ( 15 ) is substantially semi-circular or dome-shaped when inflated.  
     
     
         22 . A buoyancy device ( 1 ) according to any preceding  claim 1 , wherein the first portion ( 5 ) is restrained at substantially all points along its longitudinal axis by the restriction device ( 3 ) when inflated, and the second portion ( 15 ) is restrained at substantially all points along its longitudinal axis by the first portion and the restriction device ( 3 ) when inflated.  
     
     
         23 . A buoyancy device ( 1 ) according to claim any preceding  claim 1 , wherein the buoyancy device ( 1 ) may be operated between three configurations: 
 a) a non-inflated configuration;    b) a water inflated configuration; and    c) a gas inflated configuration.