## Facts

- Ag Pro owned a patent claiming a dairy barn arrangement and a water flush system for removing cow manure from barn floors.
- The claimed system combined sloped floors, water tanks or pools, an abrupt-release mechanism, and drains at the lower end of the slopes.
- When water was abruptly released, a sheet of water flowed across the floor and carried waste into drains quickly, without supplemental hand labor.
- The parties conceded that each element (sloped floors, drains/gutters, water storage, and gravity-driven flushing) was known in the prior art.
- In infringement litigation, the district court ultimately held the patent invalid as a combination of old elements that was neither new nor nonobvious; the Fifth Circuit reversed and directed entry of judgment upholding validity.
- The Supreme Court granted certiorari to review the Fifth Circuit’s validity determination.

## Issues

1. Whether a patent claiming a gravity-driven water flush system that combines known barn-floor slopes, water storage, abrupt water release, and drains is invalid as obvious under 35 U.S.C. § 103.

## Decision

- The Supreme Court unanimously reversed the Fifth Circuit.
- The Court held the patent invalid for obviousness under 35 U.S.C. § 103.
- The Court treated the claim as a combination patent whose elements were all old and performed their established functions.
- The Court concluded the combination produced no “new or different function” beyond predictable results, despite convenience and commercial success.

## Legal Principles

- Under 35 U.S.C. § 103, a claim is obvious where it merely arranges known elements, each performing the same function it was known to perform, yielding predictable results.
- A combination of old elements is not patentable unless the combination produces a new or different function from the sum of the parts.
- Secondary considerations (e.g., commercial success, convenience, improved speed or cost) cannot supply patentability when the claimed advance is an obvious combination of familiar elements.

## Conclusion

The Court invalidated the manure-flush system patent because it assembled established components in a straightforward gravity-fed arrangement that did not change the function of the parts or create a new functional result, making the claimed invention obvious under § 103.


Sakraida v. Ag Pro, Inc., 425 U.S. 273 (1976)