Patent of the month August


The crown cork

Summertime is beer garden time! First Friday in August has been actually the International Beer Day since 2007 - not only to celebrate and enjoy the popular drink. It rather should be about appreciating the art of brewing and keeping it alive. The crown cork is the most commonly device used to close beer bottles. On this occasion, the invention of the crown cork by William Painter, which was titled "Bottle-Sealing Device" and filed for patent in the USA in 1892 ( US468226 ) , is our patent of the month!

A crown cork is being used to seal beverages - also carbonated ones - airtight and tasteless. The aim is to preserve the quality of the bottle’s content and guarantee a leak-proof bottle transport. Up until Painter's invention, people tried a wide variety of stoppers for lemonade, beer and other carbonated beverages, but they often leaked or simply did not hold. The swing stopper provided a remedy, but its production was associated with higher material and energy costs.

Painter countered this problem with the idea of dividing the pressure of the gas on the bottle cap on a metal sleeve with 24 prongs. The even distribution of pressure on the bottleneck ensures an airtight closure without breaking it. To prevent the bottle’s content from coming into contact with the metal sheet, the lid is coated with paper on the inside and a cork ring ensures a leak-proof seal. The crown cork also prevailed the usual swing stopper due to its lower manufacturing costs.

That same year, the passionate inventor William Painter filed a patent application for the crown cork in Germany with the number DE68350 and founded the "Crown Cork & Seal Company" in Baltimore. He invented a bottle opener ( US514200 ) to go with the crown cork, as well as a machine for closing bottles and much more. In the course of his life, he registered a total of 85 patents!

Today's commercially available crown cork only has 21 prongs by the way – other than the original – as the diameters of the bottlenecks have been reduced. It also solved the problem of tilting, which was often caused by crown corks with an even number of serrations in the feed lines of the filling machines because two serrations were always exactly opposite each other. In Germany, crown corks with the DIN 6099 standard fit on glass bottles whose mouthpieces are produced according to the DIN 6094 standard.

PNZ Aachen wishes you a beautiful summer full of sparkling ideas!

“From idea to product" - the Patent Information Center (PNZ), RWTH Aachen University, offers services close to practice for researchers, entrepreneurs, craftsmen, founders and inventors!



Wikipedia: Der Kronkorken

Wikipedia: Internationaler Tag des Bieres

WDR Stichtag - Patent Kronkorken Warum der Kronkorken drei Zacken verloren hat