DIVISIONAL PATENT APPLICATIONS - A cunning tactic?

In New Zealand (and in many other countries) it is possible to file divisional patent applications. In most cases this must be done before an application is accepted for grant.

The usual reason for filing divisional applications is that patent specifications can contain discussions on two or more inventions and separate protection is required for each. In the language of patent law, you must have unity of invention per patent application.

Sometimes when patent applications are prepared the applicant is uncertain as to which aspect of the invention is the most important. Therefore the applications are often drafted to allow for dividing out at a later stage - this being a more cost effective approach than filing individual patent applications.

Filing individual applications gives you greater flexibility. If a client decides to drop one aspect of an invention and proceed with another you can re-file a separate application for the dropped aspect. If two or more inventions are in one patent specification, then you are committed to the same priority date and making decisions with respect to all of the inventions at the same time.

There is another reason for filing divisional applications. If a parent application is opposed, it is possible that a divisional application may still be in the examination process. This divisional could be amended to overcome deficiencies in the parent application, or claim alternate subject matter.

While a parent application can be amended after acceptance, the rules regarding this are very strict - for example, different subject matter cannot be claimed and only a narrowing of existing claims is permitted.

The tactic of filing divisional applications should be considered if:

• A client has a very important invention and they wish to file a divisional as insurance; and,
• There is additional material within the parent specification that is worth claiming in the divisional.

The last point is quite important. If the original patent application is overturned because the claimed invention is not considered to be novel or inventive, then the divisional will likewise be similarly affected - unless the patent specification has fair basis that enables a different invention to be claimed.

Patent attorneys specialise in intellectual property strategy and can work the legal system to client's advantage - provided they know what the client wants to achieve.

By Kate Wilson, partner