## Facts

- John Woodcock sued David Parker and another defendant in an action on the case, alleging infringement of Woodcock’s patent for a leather-splitting machine.
- Woodcock introduced letters patent dated May 8, 1809, covering a machine for splitting leather.
- Defendants admitted using a similar machine but claimed a right derived from Samuel Parker.
- Samuel Parker had obtained letters patent dated July 9, 1808, for the same machine and a further patent dated April 26, 1809, for improvements.
- The trial centered on (i) whether Woodcock or Samuel Parker was the first inventor of the machine, and (ii) whether Woodcock’s patent, even if based on improvements, impermissibly covered machinery previously invented and used by Parker.
- Justice Story instructed the jury on the controlling patent-law rules governing priority and the permissible scope of improvement patents.

## Issues

1. When two patents cover essentially the same machine, does the first inventor who reduced the invention to practice and obtained a patent have superior right over a later independent inventor who also obtained a patent?
2. If a patentee contributed only improvements, is the patent invalid or unenforceable to the extent it claims more than the improvement and reaches prior machines or prior art used for the same purpose?

## Decision

- The court instructed that the first inventor who reduces an invention to practice and obtains a patent is entitled to priority of patent right.
- A later inventor cannot, by later obtaining a patent, displace the first inventor’s right or sue the first inventor (or those holding under him) for using the original invention.
- If the jury found Samuel Parker to be the first and original inventor and defendants to have a valid derivative right from him, Woodcock could not maintain the infringement action, even if Woodcock added later improvements.
- The inventor of an improvement may not obtain a patent broader than the improvement; the patent must not cover machinery previously invented and applied to the same purpose by another.

## Legal Principles

- Patent rights belong to the first and original inventor who reduced the invention to practice and secured patent protection; later independent invention does not defeat that priority.
- A later-issued patent does not authorize its holder to exclude a prior inventor from practicing the prior inventor’s own invention.
- Improvement patents must be confined to the improvement; an improver cannot lawfully claim the entire preexisting machine or prior implementations as part of the monopoly.
- In an infringement dispute involving competing patents, priority and the boundary between an original invention and later improvements are fact questions that control liability when properly established.

## Conclusion

The case established that priority in patent rights rests with the first inventor who reduced the invention to practice and patented it, and that a patent for an improvement is enforceable only to the extent it is limited to the improvement rather than claiming earlier machines or prior applications.


Woodcock v. Parker, 30 F. Cas. 491 (C.C.D. Mass. 1813)