When Was the First Patent Filed for a Drink-through Lid?
The disposable coffee cup lid falls squarely in the category of random, everyday objects that you might assume are overlooked, but are actually quite the opposite. In fact, they have been collected, dissected, and put on display by a handful of notable design critics and curators.
As early as 1995, design historian and author Phil Patton’s personal collection of over 30 different lid types underwent categorization and analysis in a feature article for I.D. Magazine. Under the headline “Top This,” Patton noted that Americans get through about a billion and a half plastic lids each year, and marveled at “how many varieties there were, how various and intricate the device is and how intensely designed they are.”
Many drink lids have been designed to feature the name of a store or the logo of a restaurant. Drink lids also often have “buttons” that allow a server to depress a particular button to indicate what type of drink is inside the cup. This feature helps if you bring a tray full of drinks back to your table and have to figure out who got the diet soda.
The earliest drink lids were probably simple covers meant to keep drinks from spilling when moved. It wasn’t until 1934, though, that historians believe the first patent for a drink-through lid was filed.
The earliest drink-through lids had to have a hole torn in them manually, and the drinker would then have to discard the extra piece of plastic. Finally, in 1975 a patent was filed for a drink lid with a fold-back tab that would attach itself to the lid to stay out of the drinker’s way.
It was the 1980s, though, that saw major progress in drink lid design. As many as 26 new patents were filed in the 1980s for all sorts of improvements, including comfort, fit, splash reduction, and one-handed use.
One such improvement in plastic coffee cup lids is a tiny hole that’s usually located opposite the hole you take a sip through. It’s there for scientific purposes that just happen to make your drinking experience safer and more pleasant.
If you’ve ever tried to empty a gallon of water by tipping it upside down, you know that the water will not pour out smoothly. Instead, it flows in fits and bursts while it bubbles and splashes. This is because air must get into the container to replace the liquid that’s being poured out, and there’s only one hole for liquid to exit and air to enter.
When the smooth flow of liquid stops momentarily, that’s when the liquid is being forced to stop to allow air to enter the container. Can you imagine what it would be like if hot coffee bubbled and splashed as you were trying to drink it? You would likely end up with some severe burns.
Instead, drinking coffee through a plastic drink lid is a pleasant experience, because that tiny hole allows air to enter the container as the liquid leaves it. This constant flow of air into the container allows the liquid to flow smoothly without bubbling or splashing, because the air doesn’t have to try to enter the same hole the liquid is exiting.
Likewise, the second hole also acts as another exit for steam from inside the cup. A sealed lid could easily melt from the steam created by scalding-hot coffee. However, the drinking hole and the second, tiny hole both allow steam to escape to keep the lid from melting.