US 2,002,078,831 · Filed 2000-12-22

The Patent Behind Your Single-Serve Coffee Pod System

Imagine a pre-filled cartridge that clips into a machine and shoots hot water through flavored material to make your drink instantly—no mess, no scooping, no cleanup. This patent describes exactly how that cartridge design works, from the way it connects to the machine all the way to how it creates that perfect foam on top.

Curated and verified by the IsItPatented Editorial team

The plain-English version

What it protects

The claim covers a cartridge system with a pressurized inlet, a chamber holding flavor or particle material, and an outlet that can create a high-speed jet or foamy stream. What's specifically protected is the design where the inlet opening is much smaller than the chamber itself—a deliberate choice that reduces pressure stress on the seal between cartridge and machine. The patent also covers the outlet's ability to form a foamy head by mixing the fluid jet with air, and optional freshness-extending additives.

Why it matters

This design became the foundation for modern single-serve beverage systems. By making the cartridge self-contained and simple to load, it eliminates both the mess of loose grounds and the labor of cleaning—two huge consumer pain points. The smaller inlet opening is a clever engineering choice that makes the seal more reliable, which means fewer leaks and failed cartridges. This kind of reliability engineering is what separates a convenient product from a frustrating one.

Real-world use

Every time you pop a coffee pod or beverage cartridge into your machine and press brew, you're using the exact geometry and pressure-management approach this patent describes.

Original USPTO abstract

A cartridge for use with a mounting head for the preparation of fluid comestibles comprising a cartridge inlet, a chamber connected to said cartridge inlet for containing suitable flavor-containing or particle materials, a cartridge outlet connected to said chamber and a handle enabling a user to hold the handle to attach and secure the cartridge inlet to the mounting head to allow the liquid to be delivered under pressure through the flavor-containing or particle materials in the chamber, through the cartridge outlet and directly into a receptacle such as a cup or carafe for consumption, thereby dramatically simplifying the preparation of the fluid comestibles and relieving the user from the tedious cleaning work. The handle comprising at least part of the wall of the chamber, which is sufficiently rigid. The cartridge inlet has a cross-section area significantly smaller than that for the chamber to reduce the force exerted by the liquid pressure to the cartridge inlet, thereby lowering the risk of breaking the seal between the cartridge inlet and mounting head. The cartridge outlet may have a restrictive opening such as an orifice for forming a high-speed fluid jet or stream and an arrangement to allow it to interact with air to generate a foamy head for the fluid comestible. A freshness promoter can be used to prolong the freshness of the flavor-containing materials.

Patent details

Publication number: US 2,002,078,831
Filing date: 2000-12-22
Grant date: Application — not yet granted
Assignee: Cai Edward Zhihua
Inventor(s): CAI EDWARD ZHIHUA
CPC class: A47J31/14

View original record on Google Patents →

Want to file your own patent?

If you're designing a new kitchen gadget or beverage system, search our patent database to see what's already locked down in the single-serve space before you build your prototype.

Free patentability scan