Safety Goggles: Soft Plastic Frame with Turnable Splash-Proof Vent Caps (Hirschmann, US 3,141,172, 1964)

Goggles that let air in but keep splashes out. A soft polyethylene frame seals on the face and holds one clear lens for both eyes. Four vents sit in the frame, each a short tube under a cup-shaped cap with holes on one side only. You turn each cap so its solid side faces the splash; air takes a winding path in, and any liquid that gets into a cap drains out of a hole at the bottom. Result: ventilated safety goggles against liquids, chips and particles, with a lens you can replace. Source: J. B. Hirschmann, US 3,141,172 (1964), with the frame and lens of his US 2,773,260 (1956). Unknown: sizes, the moulding, the strap. Picture: the patent drawing.