## Facts

- Convertible Top Replacement Co., Inc. (CTR) held rights in a patent claiming a convertible automobile folding-top structure as a combination, including fabric and metal components plus a sealing feature.
- The patent did not claim the fabric top material as a separate invention; the claim covered the overall combination.
- In ordinary use, the fabric portion typically wore out within a few years, while the metal framework and other parts generally lasted the life of the car.
- Aro Manufacturing Co., Inc. (Aro), without a license under the patent, manufactured and sold replacement fabric tops tailored for certain General Motors and Ford convertible models using the patented top structure.
- Car owners or repair shops installed Aro’s fabric to replace worn cloth, retaining the original metal framework and other components of the patented combination.
- CTR sued Aro for direct infringement and contributory infringement; the district court found liability and enjoined sales, and the court of appeals affirmed.

## Issues

1. Whether an owner’s replacement of a worn, unpatented component of a patented combination constitutes permissible repair or infringing reconstruction.
2. Whether supplying the replacement component can constitute contributory infringement under 35 U.S.C. § 271(c) when the owner’s replacement activity is non-infringing.

## Decision

- The Supreme Court reversed.
- The Court held that replacing the worn fabric portion of the patented convertible-top combination was permissible repair, not reconstruction.
- Because the car owners’ conduct was not direct infringement, Aro could not be liable for contributory infringement under § 271(c) for supplying the replacement fabric.

## Legal Principles

- A purchaser of an authorizedly sold patented article has a right to preserve its useful life through repair, including replacement of unpatented parts that wear out in normal use, so long as the activity does not amount to making a new patented article.
- For combination patents, infringement analysis focuses on whether the accused conduct effectively creates a new instance of the patented combination, not merely on the importance or cost of the replaced part.
- Contributory infringement under 35 U.S.C. § 271(c) requires an underlying act of direct infringement; absent direct infringement by the user, supplying an unpatented replacement part does not create contributory liability.

## Conclusion

The Court held that replacing the worn fabric element of a patented convertible-top combination was lawful repair, and that, because the users committed no direct infringement, the supplier of the replacement fabric was not liable for contributory infringement.


Aro Mfg. Co. v. Convertible Top Replacement Co., 365 U.S. 336 (1961)