Face Shield with a Replaceable Window: Flood, 1946

A face shield is a transparent window hung in front of the face from a headband. Shields get pitted and worn and must be replaced, and if the fastenings are fixed to the shield they are thrown away with it. Oscar S. Flood of Chicago patented a remedy in 1946, US 2,406,598: punch a row of holes along the shield's top edge and fasten it to the visor with snap fasteners, or with a spring-steel strip whose tongues pass through the visor. A worn shield is unsnapped and a new one put in, and all the hardware stays on the visor.