1918 – Diving Armor – Rudi De Graff (Russian / American)
 1918 – Diving Armor by Rudi De Graff. Publication number US1368786 A Publication type Grant Publication date Feb 15, 1921 Filing date Jan 12, 1918 Priority date Jan 12, 1918 Inventors Rudi De Graff The invention relates to diving suits designed for service at great depths, one hundred feet or more, and the object …
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