The provision of divisional application derives its nexus from the concept of 'Unity of Invention' which is an administrative requirement present in various forms in the Patent Laws of Countries around the world. The formal requirement restricts the applicant from claiming more than one invention in a single application.

Initially, the Patents and Designs Act, 1911 did not provided any opportunity to the applicant to protect its multiple inventions disclosed in one patent application by way of divisional application, rather the controller had the power to refuse the patent application on the basis of multiplicity of invention or may direct the applicant to straightaway delete the additional inventions from the application. For the first time in the Indian patent history the mechanism of filing divisional application for the protection of multiple inventions disclosed in single patent application, was introduced by Patents and Designs (Amendment) Act, 1930.

Though, the provisions of divisional application was introduced way back in 1930 but still Indian patent office lack clarity when it comes to differentiating between applications to allow or deny divisional.

The question which needs to be given a wider prospective by the IPO is whether the inventor should get a second chance to add new claims to already disclosed invention? Is the process of so called "after claiming" is legal in view of public interest prospective? Do divisional applications meet the objective to produce manifold patents with an attempt to build a strong portfolio? What should be the criteria of legitimate division of an application?

IPAB rulings on divisional applications

If we see IPAB rulings in LG Electronics Inc v Controller of Patents & Designs (OA/6/2010/PT/KOL), Bayer Animal Health GmbH v Union of India (OA/18/2009/PT/DEL) and Syngenta Participations AG v Union of India (OA/17/2009/PT/DEL), the issues raised and resolved by IPAB in these cases were peculiar to the switching over from process patent regime to the product patent in 2005.The voluntary division of the application in these cases in fact, was an attempt to rewind the examination clock to hoodwink the earlier objections on non- patentability of product patent. This situation no longer exists now. Most of the mail box applications or other applications filed between 1995 and 2005 would have been examined and disposed. With fear of submarine patents like 'Hyatt shock' to computer industry giants relating to 'microcontroller' or 'liquid crystal displays' or Lemeision's 'submarine patent salvos' on "machine vision" patents (Barcode readers) by use of Byzantine tactics to exploit loopholes of the patent system, being a remote possibility, a re-look to the exiting practice of IPO in relation to suo moto division of patent application is required.

IPAB Ruling on Suo moto division

If we see the later decisions of IPAB we find further clarity in relation to filing of suo moto divisional application particularly in Milliken & Company v Union of India (OA/61/2012/PT/MUM). In this case it was held that the applicant's second divisional application, which was filed voluntarily without receiving an objection on lack of unity in the first divisional application, was valid. In this case applicant's request for voluntary amendment of claims for adding new set of claims during prosecution of the first divisional application was disallowed. IPAB held that in the absence of any other efficacious remedy to pursue the scope of the disallowed claims filing of the second divisional application is valid. It is clearly an indication towards suo moto division of an application to allow filing of further application with new set of claims.

The IPAB upheld the validity of the voluntary second divisional application, without looking into presence of multiple inventions.

'After Claiming'

The 'after claiming' in Milliken ruling of IPAB ,though raised many eyebrows on the issue of uncertainty but same can be answered by mandatory early publication of the new set of claims and subjecting these claims to the public scrutiny of pre-grant representation. The new set of claims may or may not have adversely affected the public. But this potential danger would be eliminated as every divisional application is treated as substantive application and it is governed by the requirement of mandatory publication. Rule 24 B (iv) provides a time limit for making request for examination of further applications filed under Section 16

(iv) The request for examination of application as filed according to the 'Explanation' under sub-section (3) of section 16 shall be made within forty-eight months from the date of filing of the application or from the date of priority of the first mentioned application or within six months from the date of filing of the further application, whichever is later;

Further as per the proviso to Rule 24 B (2)(i) as amended on 16.05.2016 not only early publication but also out of turn examination is envisaged in respect further application filed under section 16.The proviso reads as

"Provided that in case of a further application filed under section 16, the order of reference of such further application shall be the same as that of the first mentioned application:

Provided further that in case the first mentioned application has already been referred for examination, the further application shall have to be accompanied by a request for examination, and such further application shall be published within one month and be referred to the examiner within one month from the date of such publication.";

These changes in the rules are step forward in treating the further applications (divisional applications) distinct from other substantive applications. Having said so, such changes are merely facilitating the examination process. It in no way provide for special treatment to further applications.

Ex post addition of claims

The premise that an applicant is voluntarily filing a divisional application for the sole purpose of adding new set of claims when such an amendment in the parent application was disallowed raised no eyebrows in respect of IPAB ruling in Milliken. Rather, it is seen as opportunity to include additional matter. But one should not forget in US multiple applications (Continuation in part) are filed to bring the best claims to reap the maximum benefit of the invention in shortened term of 20 years. Without going much into these details let us see how this worked in US. The systematic filing of a succession of continuation applications can delay the prosecution of the patent application by number of years and during this prosecution delay new set of claims are added. The later granted patents in fact were modified to match the standards, the technology has established by then. These modified continuation application were also filed as PCT applications thus covering the protection worldwide.

Practice of after claiming rule

Filing of patent of addition does have certain issues relating additional claims when we see how this actually works in practice during infringement proceedings. 'After claiming' raises two major issues. Firstly it allows the patentees to cover more than what they actually invented. Secondly it subject unwary competitor to goal post shifting effect of claims to know the true scope of a patent. If we see the windfall to the inventor and transaction cost to the competitor we will see that it goes against public policy of fair and just reward to the inventor.

Hyatt and Lemelson submarine salvos

Some expert feel this is an attempt to shock the industry and reap the benefit when such a patent is granted later. Hyatt's 'submarine patents were such examples of how he manipulated the patent system to keep his patent pending till the computer industry was hot to strike. No doubt he made more than $150 million from license deal of 23 patents including microcontroller patent with Royal Philips NV. Hyatt microcontroller patent was later invalidated but by that time substantial royalties were received by him. Similarly Lemelson collected over $1.3 billion in royalties for his bar code technology patents before it was found invalid under the doctrine of laches in 2005 citing 'unreasonable long .... delay in prosecution' and ruling this patent 'prejudice to the public as whole.'

Disclosure - Dedication rule

Generally the patent specification disclosure forecloses addition of further claims during prosecution stage except by way of modifications in the already filed claims. If the applicant failed to claim certain subject matter disclosed in the specification he will be bared as it will be 'deemed to be dedicated to the public'. Applicability of this rule is not absolute. if we see Pfizer Inc Vs Teva Pharmaceuticals, case apart from other aspects, the Federal Circuit made a notable clarification relating to dedication of subject matter to the public for the purposes of the doctrine of equivalents. The Federal Circuit clarified that

"the public notice function of patents suggests that before unclaimed subject matter is deemed to have been dedicated to the public, that unclaimed subject matter must have been identified by the patentee as an alternative to a claim limitation."

Avoiding 'disclosure dedication rule'

In Indian patent practice there are no such precedence. The applicants can avoid the application of 'disclosure dedication rule' to the subject matter disclosed, but not claimed in the application if he is vigilant to protect the unclaimed subject matter. He has two options

1. Filing a co-pending application during prosecution

An applicant can claim the subject matter in a co-pending application before the patent issues by filing a divisional application. In India such applications are subjected to the scrutiny under section 16. Recent Milliken ruling of IPAB clearly gives such an indication towards suo moto division of an application into further application with new set of claims.

2. Filing a patent of addition

Second option with the applicant is to seek patent of addition under section 55 which is available to him any time after the grant of patent. This option does allow some leverage to the patentee to cover the minor improvement but he has to wait till the parent patent is granted.


Considering the need for allowing the patentee to cover the unclaimed subject, suo moto filing of divisional application is the better option. The inventor should get a second chance to add new claims to already disclosed invention though filing of divisional application subjected to all safeguards available to public. Moreover, some room for correcting claims should be made to avoid over-deterring claim drafting mistakes by the inventor or his attorney.

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.