You can freely build on How Keurig's Original Single-Serve Coffee Pod System Works

What this patent covers

This patent details a system for brewing beverages, specifically coffee, using a special cartridge. The cartridge has a base and a cover, both impermeable and pierceable. Inside, a filter element divides the cartridge into two chambers: one for beverage extract (like coffee grounds) and another for the brewed liquid. When you use the machine, liquid is injected into the first chamber to combine with the extract. The filter then lets the brewed beverage pass into the second chamber, from where it flows out. Claims 1 and 2 describe the core components: a housing with a brewing chamber, a pierceable cartridge inside, and means to inject liquid and collect the beverage. For example, Claim 15 specifies how the liquid inlet might go through one part of the housing and the outlet through another.

What is now free to use

All 0 claims of US 5325765 are in the public domain. Specifically:

The 0 dependent claims add narrowing limitations and are also free.

What is NOT covered

Patent expiry frees this specific invention. Separately-patented improvements made after expiry may still be protected.

• Beverage cartridges that are not internally divided by a filter element.

• Systems where the filter element does not create two separate chambers within the cartridge.

• Cartridges that are not pierceable by inlet and outlet means.

• Brewing systems that do not use a removable cartridge.

• Methods of brewing that do not involve combining liquid with a beverage extract stored in a chamber.

Who is building on this today

Keurig Dr Pepper continues to be the dominant player, leveraging this foundational technology. However, the widespread adoption of single-serve brewing has led many other companies to develop compatible pods and brewing systems, often navigating the landscape of expired and related patents.

Products built on expired version of this technology

How to cite this patent in your documentation

Keurig Inc. US Patent 5325765. Beverage filter cartridge. Granted 1994, expired 2012. Now in the public domain.

Note: This is a convenience citation. Consult a patent attorney for formal freedom-to-operate analysis.

PatentBrief is an educational resource and does not provide legal advice. Patent expiration information is derived from USPTO records and may not reflect continuation patents, divisional filings, or separately-patented improvements. For commercial use or production decisions, obtain a formal freedom-to-operate (FTO) opinion from a registered patent attorney.