Considering claims when filing a provisional patent

The scope of protection afforded by a granted patent is defined by the claims in the complete specification. Generally, for a complete patent to be infringed, every feature mentioned in one of the claims must be present in the infringing article. The fact that the infringing article: (a) includes additional features, or (b) is itself patented, is irrelevant to the issue of infringement.

A provisional patent application does not need to include a set of claims. However, we strongly suggest preparing a set of claims at this stage, for the following reasons:

Directing R&D activities

R&D processes are aimed at solving uncertainties. In some instances, the "solution" comprises many steps that can follow different paths.

Researchers should conduct searches periodically throughout the R&D process to identify potential problem patents. This information could then be used to:

Preparing a draft set of claims highlights the "finish point" and identifies "virgin territories" along the way.

Understanding the scope of protection offered by a patent

Patent protection is only available for new and non‐obvious features.

Frequently, features that researchers consider to be core and patentable are, following searches, found to be within the public domain.

Preparing claims at the provisional stage forces researchers to identify the novel features of the invention. Thereafter, having regard to the potential scope of patent protection offered by the draft claims, the researchers can make an informed decision as to whether further research is commercially feasible.

Determining whether an invention can easily be designed around

Many new inventions evolve from known products or merely extend the application of known products into a new field of use.

During the R&D process, research is frequently directed at perfecting the "new invention" and a working prototype.

Assuming that: the "new invention" comprises parts X, Y and Z (which part the researchers originally considered ancillary); and searches show that parts X and Y (and numerous variants thereof) are generally known, but that part Z is described briefly in only a few prior art documents. If the researchers focus on modifying parts X and Y, their efforts will most probably fail to be rewarded by patent protection. Their efforts would more effectively be directed at part Z ‐ a natural tension exists between perfecting the prototype and securing suitable patent protection.

With their focus properly directed, the researchers can now consider more fully the possible practical alternatives of patentable features ‐ the more practical alternatives claimed, the more difficult it will be for competitors to design around the resultant patent(s).


Inventors should, as a matter of course, conduct searches and prepare a set of claims before filing provisional patent applications. If the inventor fails to do so, he may at the time of preparing the complete specification (i.e. 12 months and many thousands of Rands later) find that:

(Updated 2007)

Articles: Patent issues