US 4,509,412 · Granted 1985-04-09

The 1985 Steamer That Kept Condensation Out of Your Food

Imagine a cooking pot that uses steam to cook your vegetables or seafood, but has a clever trick: it separates the water droplets that form during cooking so they don't drip back onto your food and make it soggy. The patent covers the design that makes this separation work automatically.

Curated and verified by the IsItPatented Editorial team

The plain-English version

What it protects

The claim covers a steam cooking device with a specific layout: a central water reservoir surrounded by an annular trough that catches condensate (the water droplets that form when steam cools). A food tray with a solid center sits over the reservoir and perforated edges sit over the trough. A cover with a rim seals against the trough to trap steam. What's protected is this combination of the sealed condensate management system, the dual-zone tray design, and the thermostat-controlled heating element that prevents excess moisture from reaching the food.

Why it matters

This patent solves a real practical problem with steam cooking: traditional steamers let condensation drip back onto food, making it waterlogged and less appetizing. By designing a trough to intercept and separate that moisture before it reaches the food, this device improved both the quality and texture of steamed meals. Rival Manufacturing, a major small-appliance maker, would have used this innovation to differentiate their steamers in a competitive kitchen-gadget market during the 1980s.

Real-world use

When you use an electric steamer to cook broccoli or fish, the dry, fluffy texture you get is partly thanks to designs like this one that keep condensation from dripping back onto your plate.

Original USPTO abstract

A steam cooking utensil is disclosed which includes a base; a boiling water reservoir and a condensate trough defined by the base; and a heater disposed centrally to the boiling water reservoir, mounted in the base, and coupled to a thermostat also mounted in the base. The condensate trough is disposed in annular relationship to the boiling water reservoir. A food tray defining a imperforate central surface and an array of peripheral aperatures is supported such that the imperforate surface is vertically aligned with the boiling water reservoir and the array of peripheral apertures is vertically aligned with the condensate trough. A cover having a bottom opening defined by a rim is positioned over the food tray, condensate trough and boiling water reservoir, such that the rim cooperates with an outer peripheral lip of the condensate trough to form a seal. The disclosed steam cooking utensil operates to cook food quickly, cleanly and efficiently. The boiling water reservoir remains free from condensate residues even after boiling dry, and the food product remains free from excess moisture.

Patent details

Publication number: US 4,509,412
Filing date: 1983-03-04
Grant date: 1985-04-09
Assignee: Rival Manufacturing Company
Inventor(s): WHITTENBURG; STEPHEN L., MCCORMICK; DAVID D., TWEED; WILLIAM J., OZGUNAY; A. AYKUT, WILLIAMS; JAMES T.
CPC class: A47J27/04

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