Invention of Scuba
In 1925 Le Prieur saw a demonstration at the Industrial and Technical Exhibition in Paris of a diver using a breathing apparatus invented by Maurice Fernez. The Fernez breathing apparatus consisted of a simple T-shaped rubber mouthpiece. On one side this was connected to a long tube down which air was pumped from the surface. On the other side of the mouthpiece, excess and exhaled air escaped from a simple rubber "ducks bill" valve. The diver's nose was pinched by a pair of spring clamps ("pince nez") to prevent ingress of water, and his eyes were protected by small goggles with rubber surrounds.
Le Prieur was impressed by the simplicity of the Fernez equipment and the freedom it allowed the diver, and he immediately conceived an idea to make it free of the tube to the surface pump by using Michelin cylinders as the air supply. Michelin cylinders contained three litres of air compressed to 150 kg/cm2 supplied by Michelin to garages without air compressors for inflation of car tires. Le Prieur approached Fernez, who cooperated to modify his equipment to Le Prieur's idea, and on 6 August 1926 the "Fernez-Le Prieur" diving apparatus was demonstrated at the swimming pool of Tourelles in Paris. The unit consisted of a cylinder of compressed air carried on the back of the diver, connected to a pressure regulator designed by Le Prieur adjusted manually by the diver, with two gauges, one for tank pressure and one for output (supply) pressure. Air was supplied continually to the mouthpiece and ejected through a short exhaust pipe fitted with a valve as in the Fernez design. For the first time a man could breathe underwater with no connection to the surface at all – Le Prieur had invented the self-contained underwater breathing apparatus – scuba.
Fernez's separate goggles didn't allow a dive deeper than ten metres because they were not pressurised, so as the diver went deeper the goggles were squeezed onto his face and eyeballs by the increasing water pressure, a phenomenon known as "mask squeeze". In 1933, Le Prieur replaced the Fernez goggles, noseclip and valve by a full face mask, directly supplied from the air cylinder, which balanced the pressure in the mask with the external water pressure. In 1934 Le Prieur was granted French patent 768083 for an improved hand-controlled self-contained underwater breathing apparatus with full face mask. The patent application was lodged in Paris on 2 February 1934 at 2:32 pm. The patent was awarded on 7 May 1934 and the patent specification was published on 31 July 1934. The equipment delivered air at constant pressure without a demand regulator. Compressed air was contained in a cylinder carried on the diver's chest in a harness, delivering air to the full face mask at a pressure controlled by a hand operated regulator. Excess air, and the diver's exhaled breath, escaped by slightly lifting the edges of the mask.
In 1946, Le Prieur invented a further improvement to his scuba set. Its fullface mask's front plate was loose in its seating and acted as a very big, and therefore very sensitive, diaphragm for a demand regulator: see Diving regulator#Demand valve.
Read more about this topic: Yves Le Prieur
Famous quotes containing the words invention of and/or invention:
“The invention of photography provided a radically new picture-making process—a process based not on synthesis but on selection. The difference was a basic one. Paintings were made—constructed from a storehouse of traditional schemes and skills and attitudes—but photographs, as the man on the street put, were taken.”
—Jean Szarkowski (b. 1925)
“Methinks the human method of expression by sound of tongue is very elementary, & ought to be substituted for some ingenious invention which should be able to give vent to at least six coherent sentences at once.”
—Virginia Woolf (1882–1941)