US 5,325,765 · Granted 1994-07-05

The Keurig K-Cup Patent That Brewed a Coffee Revolution

Imagine a little plastic pod filled with coffee grounds and a special filter inside. You pop it into a machine, hot water shoots through it, and out comes a perfect cup of coffee in seconds. This patent describes the clever design that makes that whole system work—sealed chambers, a filter that does the heavy lifting, and a way to keep everything contained until you're ready to brew.

Curated and verified by the IsItPatented Editorial team

The plain-English version

What it protects

The claim covers a sealed cartridge design with an impermeable base, a self-supporting filter element that divides the cartridge into two separate chambers, and a pierceable cover. What's protected here is the specific geometry and arrangement: the filter sits inside in a way that's smaller than the cartridge itself, creating a storage chamber for coffee extract on one side and a dispensing chamber on the other. The design allows liquid to pass through the filter while keeping the two sides sealed until the brewing happens.

Why it matters

This patent became the foundation for Keurig's single-serve coffee system, which transformed the way millions of people brew coffee at home and in offices. The clever two-chamber design solved a real problem: how to pre-package ground coffee with a filter, keep everything fresh and sealed, and deliver a consistent cup on demand. It protected Keurig's market dominance in the pod-based brewing space for years, making the company a major player in the kitchen appliance industry.

Real-world use

Every K-Cup pod you drop into a Keurig machine is built on this patent's design—the filter inside separates the grounds from the brewed coffee, and the sealed chambers ensure freshness until you press the brew button.

Original USPTO abstract

A beverage filter cartridge includes an impermeable pierceable base having a predetermined shape and an opening at one end; a self-supporting wettable filter element disposed in the base sealingly engages with the opening in the base and has a form different and smaller than the predetermined shape of the base so that the filter element diverges from the base and divides the base into two sealed chambers, a first chamber for storing an extract of the beverage to be made, and a second empty chamber for accessing the beverage after the beverage outflow from the filter has been made by combining a liquid with the extract; and an impermeable pierceable cover sealingly engaged with the opening in the base to form an impermeable cartridge.

Patent details

Publication number: US 5,325,765
Filing date: 1992-09-16
Grant date: 1994-07-05
Assignee: Keurig, Inc.
Inventor(s): SYLVAN; JOHN E., DRAGONE; PETER B.
CPC class: A47J31/0673

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