Today in 1939, US Patent 2155947 A was issued, an invention of Theodore H. Low, for his “Bottle Opener.” There’s no Abstract, but the description summarizes it that the “invention relates to improvements in hand decappers or openers for bottles sealed with crown caps.”
Beerman49 says
That one’s been modified to a short, no-handled version to fit on keyrings (flip hook opens cap away from you; the flat top stretches only part way across the cap).