Variable displacement recovery devices

Claim 2

An underwater lift device consisting of: (a) a gas container, such as an expansible lift bag, to provide buoyancy by displacement of water; (b) a gas source; (c) gas delivery means communicating said gas source with said gas container; (d) actuating means for said gas source to provide gas at the required pressure depth for said gas container; (e) a gas supply control valve for said gas source, responsive to contained gas pressure balanced against hydrodynamic pressure as determined by rate of ascent; (f) a gas vent valve affixed to said gas container responsive to contained gas pressure balanced against hydrodynamic pressure as determined by rate of ascent; (g) an outer container to house and protect the apparatus packaged within said outer container; and a (h) means for attachment of a load to said outer container.

Claim 3

An underwater lift device in accordance with claim 1 wherein said gas source is a chemical gas generator consisting of a chemical compound or fuel, such as an hydride of a metal selected from a group consisting of lithium, sodium, calcium, potassium, aluminum and mixtures thereof, said fuel being packaged in a fuel cartridge with a sealed closure, which when opened by hydraulic means deploys said fuel into water surrounding said fuel cartridge whereupon said fuel reacts with the water to generate relatively pure hydrogen gas, said reaction being confined by a wire grate located under said fuel cartridge and by cylindrical metal sleeve surrounding said fuel cartridge, wherein the metal sleeve serves to transfer heat from the chemical reaction and by thermo-syphon action draw fresh water into the generator as well as to purge the generator of reacted materials, such as hydroxides of the metal.

Claim 4

An underwater lift device in accordance with claim 2 wherein the reaction rate and reaction pressure within said gas generator are controlled by gas pressure differential (relative to hydrostatic pressure) developed inside of said gas container, which pressure differential is balanced by the ''''pressure head'''' established by said cylindrical metal sleeve between radial holes located near the upper and lower extremities of said sleeve, the resultant pressure being sufficient to expel water from inside said sleeve to a level below said wire grate, thereby slowing or stopping gas generation until pressure changes permit water to reenter said sleeve.

Claim 5

An underwater lift device in accordance with claim 2 wherein said fuel cartridge may be opened, to expose said fuel contents to water, thereby activating said gas generator, by means of an hydraulic line connected to said fuel cartridge through which water is injected into said sealed cartridge, either by means of hydrostatic pressure or an applied differential pressure, to react with said fuel and to break and remove said sealed closure by means of gas pressure developed inside of said Fuel cartridge.

Claim 6

An underwater lift device in accordance with claim 1 wherein the gas supply control valve is a pressure-balanced valve, such as a diaphragm valve, sensing hydrodynamic pressure on one side, as for example by means of a pitot tube with opening oriented toward the direction of travel during ascent of the device, and gas supply pressure on the opposing side of the diaphragm, said valve operating to close said gas delivery means communicating said gas source with said expansible lift bag whenever ascent rate exceeds a prescribed velocity and the resultant hydrodynamic pressure exceeds gas supply pressure.

Claim 7

An underwater lift device in accordance with claim 5 wherein the gas vent valve affixed to said gas container is a pressure-balanced valve, such as a diaphragm valve with spring loaded adjustment means, sensing hydrodynamic pressure on one side, such as by means of apertures oriented toward the direction of travel during ascent, and contained gas pressure on the opposing side of the diaphragm, said valve operating to vent contained gas from said gas container whenever assent rate exceeds a preset velocity as determined by spring bias holding said valve in the normally closed position, and resultant hydrodynamic pressure exceeds gas pressure inside said gas container in combination in said lift device in a sequential manner, first to close said gas delivery means thereby isolating said gas container from said gas supply and, second, to vent gas from said gas container until the desired vertical ascent velocity has been attained, including the suspension of loads at some predetermined depth.

Claim 8

An underwater lift device in accordance with claim 1 wherein the gas vent valve affixed to said gas container is a pressure-balanced valve, such as a diaphragm valve with spring-loading adjustment means, sensing hydrodynamic pressure on one side, such as by means of apertures oriented toward the direction of travel during ascent, and contained gas pressure on the opposing side of the diaphragm, said valve operating to vent contained gas from said gas container whenever ascent rate exceeds a preset velocity, as determined by spring bias holding said valve in the normally closed position, and resultant hydrodynamic pressure exceeds gas pressure inside said gas container.

Claim 9

An underwater lift device in accordance with claim 1 wherein the gas container consists of an expansible lift bag employing an inner bladder, constructed of thin, flexible plastic, rubber or rubberized material having low permeability to hydrogen gas, an outer sleeve, constructed of flexible but relatively inelastic material, such as vinyl coated Nylon reinforced fabrics, wherein the outer sleeve functions to protect and contain the inner bladder, as well as to support lifting loads, while the inner bladder is free to conform irrespective of load and amount of inflation, water being free to circulate between said sleeve and said bladder.