In the multifaceted world of Intellectual Property, securing robust patent protection is a strategic necessity for inventors and businesses alike. Among the tools available to patent applicants, divisional patent applications stand out for their ability to enhance the scope and flexibility of patent rights. 

Divisional Patent Applications: Splitting Inventions for Focused Protection 

Divisional patent applications are essential when an original (parent) patent application contains multiple, distinct inventions. Applicants are required to limit their claims to a single invention per patent application (to conform with unity of invention). A divisional patent application allows the applicant to carve out and pursue patent protection for the additional inventions disclosed in the parent application by filing one or more divisional patent application(s). 

A divisional patent application retains the priority date of the parent patent application, ensuring that the claims of the divisional patent application are treated as though they were filed on the same date as the parent patent application. 

The claims in a divisional patent application must be directed to an invention different from those in the parent patent application, even though they are derived from the same original disclosure. 

Despite being linked to the parent patent application, a divisional patent application is treated as a separate patent application in that it proceeds independently through to grant. 

Using divisional patent applications strategically allows applicants to comply with unity of invention requirements without losing the opportunity to protect multiple inventions disclosed in the original filing. This approach can lead to a portfolio of patents covering various aspects of an invention, each with focused and robust claims. 

Importantly though, where the claims of a divisional patent application and its parent patent application overlap, there is a significant risk of double patenting. Double patenting is recognised as an improper extension of the monopoly afforded by a patent. The risk is somewhat difficult to quantify in the South African context as South Africa does not have a substantial corpus of case law from which to make informed inferences. Reflecting on the case law that is available in South Africa, one of the leading cases (McKelvey and others v Deton Engineering (Pty) Ltd) refers to the intent of Section 25(7) of the South African Patents Act to, among other things, extend the state of the art beyond the bare recitation of absolute novelty, to include disclosures contained within patent applications (both of local and foreign origin via so-called Convention applications) where those applications contain priority dates prior to the date of the invention and are subsequently published. This, so the judgement holds, also has the effect of curtailing double patenting in practice. Here, the South African courts have further interpreted Section 25(7) in terms of the “whole contents” approach, wherein the claims of a given patent are assessed against the whole contents of a prior disclosure. Use of the whole contents approach has been held to, by its very nature, prevent double patenting. 

South Africa currently uses a depository system and accordingly, patent applications are only examined with an eye towards the formalities of the patent application. This may change in the coming years, but for now there is no assessment of double patenting, or any other substantive issues, before grant. As such; it would be up to a court to assess the presence of double patenting should such be raised during an action or counterclaim for revocation. 

Cascading of Divisional Patent Application in South Africa 

The cascading of divisional patent applications is a strategy where a series of divisional patent applications are filed sequentially. This can be particularly effective in jurisdictions like South Africa, where there is no limit to the number of divisional patent applications that can be filed, provided that each one is filed while the parent or earlier divisional is still pending (i.e. before acceptance). 

In conclusion, mastering the use of divisional patent applications is essential for inventors and businesses aiming to secure robust and adaptable patent protection. By strategically employing these tools, you can navigate the patent landscape effectively, ensuring your innovations are well-protected and positioned for success.