Nullity Proceedings in 1884

The Patent N° 532 was attacked with a nullity action at the Imperial Patent Office a first time in 1884. Information about these proceedings do not seem to longer exist. The decision of the Imperial Court of 30 January 1886 in the case of a second nullity action cites this earlier decision. In the first nullity action of 1884 claim 4 was revoked in total, claim 1 was limited, but claims 2, 3, and 5 were uphold unamended.

In their decision the Imperial Patent Office seems to have considered as prior art documents of Barnett, Hock, and Lenoir.

As an outcome of the proceedings at first instance claim 1 was substantially limited to:

1. Introducing into an enclosed space combustible, with air mixed gases in order to produce operational power by expansion and mixing them with air of a different kind before their combustion in such manner that at a point of an initiated combustion it is spreading from gas particle to gas particle whilst it is gradually slowing down, whereby the combustion products and the kind of air that envelopes them expand by the produced heat and thus release operational power, that during the suction cycle first fresh air or another indifferent gas enters, which mixes with the combustion residues which fill a space that is provided for this purpose, and then explosive gases are sucked in, such that by the latter a safe ignition is enabled.

However, the Gasmotorenfabrik Deutz as the patent proprietor appealed at the Imperial Court. In view of the prior art a limition of the original claim 1 in view of the prior art was considered necessary. However, the limitation of the Imperial Patent Office was considered to go too far. In absence of a more suitable limitation expressed in the original application claim 1 was granted as follows:

1. Introducing into an enclosed space combustible, with air mixed gases and air of a different kind before their combustion in a way as described in the patent description in such manner that at a point of an initiated combustion [the combustion is] spreading from gas particle to gas particle whilst it is gradually slowing down, whereby the combustion products and the kind of air that envelopes them expand by the produced heat and thus release operational power.

A limitation "in a way as described in the patent description" today would not be acceptable. I point to the decisions of the European Patent Office where it is emphasized that a patent claim must be understood by itself without having to consult the description or the drawings. The limitation introduced by the Imperial Patent Office would have satisfied todays clarity requirement.