## Facts

- Arthur E. Troiel filed a patent application titled “Hole Cap and Tool Therefor” for use with lumber forms into which concrete is poured.
- The problem addressed was that form lumber often had holes and surface defects; unless covered, concrete could leak through and leave an irregular finished surface.
- Troiel’s “hole cap” was a generally circular disk intended to be driven into the wood so the disk would mask the defect.
- The disk included a plurality of triangular tabs pushed out from one side of the disk only, arranged on a circle concentric with and inward of the disk’s periphery.
- The disclosure described tab details intended to improve holding in wood, including side-edge shapes near the hinge line and a slightly curved tab cross-section to increase rigidity.
- Troiel also described making the cap from magnetic material so it could be held at the end of a driving tool that had a magnetic portion; the cap could then be positioned and driven by striking the tool.
- The patent examiner finally rejected claims 2, 4, 5, and 10 (the remaining claims), relying on multiple prior-art patents.
- The cited art included: Spreen (a metal piece used to cover imperfections in concrete-form lumber, but not with concentric circular tab placement), Stowe (a disk with triangular tabs struck out from both sides used as an anchoring/anti-sliding device), Sampson (a fastener for securing conductors to a panel), and Buchner et al. and Brown (wood-penetrating tab/tang structures, including serrated tangs).
- The examiner treated Troiel’s cap as a modification of known defect-covering plates combined with known disk-and-tab anchoring structures and known tab/tang details; the Patent Office Board of Appeals affirmed.
- Troiel appealed to the United States Court of Customs and Patent Appeals (C.C.P.A.).

## Issues

1. Whether claims 2, 4, 5, and 10 defined patentable invention (nonobvious subject matter) over the combined teachings of the cited prior art concerning defect-covering plates, tabbed disks for driving into wood, and tab/tang configurations.
2. Whether including magnetic material in the cap and a magnetic holding feature in the driving tool made the claimed subject matter patentable over the art.

## Decision

- The C.C.P.A. affirmed the Board of Appeals’ decision affirming the examiner’s final rejection of claims 2, 4, 5, and 10.
- The court agreed that the claimed hole cap was an obvious variation in view of the prior art taken together, including the use of triangular tabs on a disk and the use of similar devices to cover defects or anchor into wood.
- The court also agreed that the magnetic holding aspect of the tool/cap did not supply patentable invention because it amounted to applying a known holding technique to a known driving/placement problem.

## Legal Principles

- Patentability is not shown where the claimed structure results from selecting and arranging known elements from the prior art to achieve results that would be expected by a person of ordinary skill.
- A rejection for obviousness (or lack of invention) may rest on a combination of multiple prior-art references when, viewed as a whole, the references would suggest the claimed arrangement to a skilled artisan.
- Differences from each single reference, considered one-by-one, do not establish patentability if the combined teachings of the references account for the claimed features.
- Adding a known expedient (such as magnetic holding for placement during driving) does not confer patentability when it performs its ordinary function and does not change the basic character of the combination.

## Conclusion

In *Application of Troiel*, the C.C.P.A. affirmed rejection of Troiel’s remaining claims for a disk-shaped hole cap with a concentric circle of one-sided triangular tabs (and related driving tool features), holding that the claimed subject matter would have been obvious in view of multiple prior patents addressing defect covers, wood-anchoring tabbed disks, and conventional tab/tang and magnetic holding techniques.


Application of Troiel, 274 F.2d 944 (1960)