Top hat ribs and springs. His patent was described as: Some sources have taken this to describe an early folding top hat, although it is not explicitly stated whether Dollman's design was specifically for male or female headgear. Dollman's patent expired in 1825. In France, around 1840, Antoine Gibus's design for a spring-loaded collapsible top-hat proved so popular that hats made to it became known as "gibus". They were also often called "opera hats" due to the common practice of storing them in their flattened state under one's seat at the opera, though the term can also refer to any tall formal
Kettle hat Kettle hat A kettle hat, is a type of helmet made of steel in the shape of a brimmed hat. There are many design variations. The only common element is a wide brim that afforded extra protection to the wearer. It gained its common English language name from its resemblance to a metal cooking pot (the original meaning of "kettle"). The kettle hat was common all over Medieval Europe. It was called "Eisenhut" in German and "chapeau de fer" in French (both names mean "iron hat" in English). It was worn by troops of all types, but most commonly by