## Facts

- Expanded Metal Company sued Bradford and others (and, in a related case, the General Fireproofing Company) for infringement of U.S. Patent No. 527,242, issued to John E. Golding for a method of making expanded sheet metal.
- Expanded sheet metal is openwork formed by cutting slashes in metal and then opening the sheet to create meshes connected by uncut portions.
- Prior techniques generally required two distinct steps: cutting the metal and, separately, stretching it to open the mesh, which limited commercial usefulness.
- Golding’s claimed improvement performed cutting and expanding simultaneously, producing expanded metal more efficiently and with greater practical utility.
- Two circuits issued conflicting rulings: the Third Circuit held the patent invalid; the Sixth Circuit held it valid and infringed, leading to Supreme Court review.

## Issues

1. Whether a claimed mechanical method of manufacturing expanded metal is a patentable “process,” or whether process patents are limited to chemical or elemental transformations.
2. Whether Golding’s claimed method was a valid improvement rather than an unpatentable statement of a machine’s function or result.
3. If the process claim was valid, whether defendants infringed it by using a substantially similar simultaneous cutting-and-expanding method.

## Decision

- The Court held that mechanical methods can constitute patentable processes and are not confined to chemical or elemental changes.
- The Court concluded Golding claimed a definite series of operative steps (simultaneous cutting and expanding), not merely a desired result or machine function.
- The Court ruled the process claim valid as a substantial improvement producing a new and useful result independent of any particular machine embodiment.
- The Court reversed the judgment invalidating the patent (Third Circuit line of cases).
- The Court affirmed the judgment upholding validity and finding infringement (Sixth Circuit line of cases).

## Legal Principles

- A process (method) and the apparatus that performs it are distinct and may be patented separately; process validity does not depend on confinement to a specific machine.
- A mechanical process may be patentable if it consists of a sufficiently definite method of doing a thing that skilled artisans can carry into operation using appropriate mechanisms.
- A claim is not patentable if it merely states a machine’s function or effect; it is patentable if it claims a concrete series of acts producing a new and useful result.
- A new combination of known steps or elements can be patentable when the combination yields a new and useful result.
- Patentable “processes” are not limited to chemical action or elemental transformations; mechanical operations producing a new and useful result may qualify.

## Conclusion

The Supreme Court upheld Golding’s process patent for simultaneously cutting and expanding sheet metal, rejected a chemical-only limitation on process patents, and resolved the circuit conflict by restoring validity and sustaining an infringement judgment where defendants practiced the same method.


Expanded Metal Co. v. Bradford, 214 U.S. 366 (1909)