Kutti Bay Investments Pty Ltd v Rattlejack Innovations Pty Ltd

Kutti Bay Investments Pty Ltd v Rattlejack Innovations Pty Ltd [2026] FCA 422 is a Federal Court interlocutory decision about patent amendments, earlier losses on related patents, and abuse of process. The dispute sat within a broader commercial fight over mining safety technology, specifically patents for a safety system intended to protect against hazards arising from drill rod failure in drilled rock bores.

The Court did not finally decide infringement or overall validity in this ruling. Instead, it dealt with a threshold procedural fight. Kutti Bay had applied to amend the patents it was suing on. The respondents argued that parts of that amendment application were really an attempt to get around findings already made in earlier litigation involving related patents from the same family. Rofe J agreed in part and declared that the amendment application was an abuse of process to the extent it sought to overcome those earlier findings.

Kutti Bay, formerly Jusand Nominees, was the registered owner of three standard patents: Australian Patent No. 2015255248, No. 2021200376 and No. 2021215238. Each was entitled "Safety System and Method for Protecting Against a Hazard of Drill Rod Failure in a Drilled Rock Bore". Kutti Bay alleged that the respondents' Safety Spear product infringed certain claims of those patents.

The present case did not arise in isolation. The same commercial conflict had already been litigated in earlier proceedings involving three innovation patents from the same patent family. Those earlier patents also claimed priority from the 248 patent. In the earlier case, the respondents successfully defended the infringement claims and brought revocation cross-claims. The trial judge found the asserted claims invalid for lack of clear and complete disclosure and lack of support, and also found no infringement. The Full Court upheld that result, and special leave to appeal to the High Court was refused.

The family relationship between the patents mattered. The Court recorded that the 248 patent was the priority document for the earlier innovation patents. The 376 and 238 patents were divisional children of the 248 patent. The Court also said the patents in suit in the present proceeding were substantially the same as each other and materially the same as the innovation patents from the earlier case.

That earlier litigation produced findings that became central in the new dispute. The Court had already construed the term "anchor member" and held that the claims encompassed only de minimis movement of the anchor member, in the order of a few millimetres, not substantial movement down the bore hole. The Court had also construed the phrase concerning the proximal end region of the bore adjacent to a rock-face, and had made findings about disclosure and support, especially that the claims were not limited to steel but the specifications did not provide sufficient guidance for making the system out of materials other than steel without inventive effort or undue burden.

After those earlier losses, IP Australia re-examined patents in the same family under s 97(2) and considered that the claims lacked disclosure and support for the same reasons identified in the earlier court decisions. Following that adverse report, Kutti Bay said it was required to take action to prevent revocation of the patents. It commenced the present proceeding and then applied to amend the patents under s 105(1), saying that a court amendment process would be more streamlined and efficient than seeking amendment through the Patent Office.

The respondents did not object to the mere fact of an amendment application. Their objection was to the form and purpose of this one. They said the proposed amendments, together with the new expert evidence filed in support, were aimed at overcoming the earlier findings rather than simply correcting obvious mistakes or making permissible changes.

The legal issue was not whether patents can ever be amended. The respondents accepted that amendment applications are available under the Patents Act. The narrower question was whether this particular amendment application, or part of it, was an abuse of process because it sought to overcome findings already made by the Court and the Full Court in the earlier Jusand litigation.

At first, the respondents had raised several procedural grounds, including issue estoppel and Anshun estoppel. But by the hearing they no longer pressed those grounds. Abuse of process was the only live contention. The respondents said the amendment application sought to re-agitate construction issues already determined by the Full Court, invoke the Court's amendment power in a way that would undermine earlier decisions, expose them to being twice vexed, and create a material risk of inconsistent findings.

The Court also noted the procedural posture of the case. Although the present proceeding had been commenced in December 2024, it remained at an early stage. Defences had not yet been filed and no cross-claim had been filed. At the respondents' instigation, the Court ordered that the abuse applications be heard and determined before the amendment application itself. That is commercially significant because it shows how a procedural challenge can become the first major contest in a patent case.

The available reasons identify several categories of proposed amendments that drew objection. First, Kutti Bay sought changes to references describing where the anchor or plug member was fitted. This included deleting the word "end" or replacing it with "region" in certain descriptions. Second, it sought to delete descriptions of the proximal end region of the bore as being "at" or "adjacent to" the rock-face, as distinct from the remote or distal region of the bore. Third, it proposed to substitute Figure 3, which presently depicted a safety system installed at the collar of the borehole, with a depiction of a safety system installed some distance into the borehole.

Kutti Bay also sought to insert a common general knowledge statement into each specification and to make minor spelling and labelling corrections. The respondents did not object to spelling corrections. Their real concern was with the substantive changes and the proposed common general knowledge statement.

The Court's extract gives a concrete example of the respondents' complaint. They argued that if the anchor member no longer needed to be fixed in the proximal end region of the bore adjacent to a rock-face in the way previously understood, then Kutti Bay's position would permit the anchor member to move a non-de minimis distance down the bore hole following impact by a drill rod. That sat directly against the earlier findings that the claimed anchor member involved only de minimis movement of around a few millimetres, not substantial travel down the bore.

The amendment application was supported by evidence from three new experts who had not given evidence in the earlier Jusand proceedings: Professor Ernesto Villaescusa, Dr David Tawfik and Mr John Tucker. The extract records that Professor Villaescusa, using assumptions provided by Kutti Bay's lawyers, expressed the expectation that the claimed safety system would displace "some distance" within the bore hole, said to be 100mm to 200mm. The extract then notes that this was quite different to the de minimis movement identified in the earlier findings. Because the available text is truncated at that point, the full treatment of this evidence is not available here.

Rofe J upheld the abuse applications in part. The Court declared that Kutti Bay's interlocutory application dated 25 April 2025 seeking to amend the patents in suit, insofar as it sought to "overcome" the Court's findings in Jusand Nominees Pty Ltd v Rattlejack Innovations Pty Ltd [2022] FCA 540 and Jusand Nominees Pty Ltd v Rattlejack Innovations Pty Ltd [2023] FCAFC 178, was an abuse of process.

The Court then ordered that the respondents' interlocutory applications be allowed in part, that Kutti Bay pay the respondents' costs of and incidental to those applications subject to further order, and that the matter be listed for a further case management hearing.

The wording of the declaration is important. It was expressly limited to the extent the amendment application sought to overcome the earlier findings. On the available text, the Court did not say every amendment was impermissible. Nor did it finally determine the substantive infringement case. The ruling was targeted at the use of the amendment process to circumvent earlier judicial conclusions on related patents in the same family.

Because the available reasons are truncated before the judgment finishes, this page cannot describe the full detail of the Court's reasoning on every proposed amendment or the complete final treatment of each category of change. But the central point is clear from the declaration and the reasons that are available: the Court was prepared to police the purpose and effect of the amendment strategy where it cut across earlier findings.

If your business owns a patent family, this case is a reminder that family members are not commercially independent just because they have different patent numbers. Earlier findings on one family member may shape how a court views later patents, later amendments and later expert evidence. That is especially true where the patents are materially similar and the earlier case has already settled key questions about claim meaning, disclosure and support.

The decision also shows that amendment strategy, litigation strategy and technical evidence need to be aligned from the start. A business cannot safely assume that a later amendment application will be treated as a clean slate. If the amendment appears designed to avoid the practical effect of earlier findings, the other side may attack it as an abuse of process before the main infringement case even gets going.

For management teams, the commercial risk is not limited to losing the final case. There is also the cost of interlocutory fights, adverse costs orders, delay, and the possibility that enforcement momentum will be lost while procedural issues are argued. That can affect settlement leverage, investor confidence, licensing discussions and product launch decisions.

The case is also a reminder to treat Patent Office events as part of the same commercial picture. Here, IP Australia had re-examined related patents and considered that the same disclosure and support problems identified by the Court applied to the patents in suit. For a business, that means an adverse court judgment can spill into re-examination risk and then feed back into litigation and amendment strategy.

Most importantly, do not overread the decision. It does not say all amendments are barred after an earlier loss. It says amendments aimed at overcoming earlier findings may be blocked. That distinction matters. Genuine corrective amendments may still be possible, but they need to be assessed carefully against the history of the patent family and the findings already made.

The judgment is dated 13 April 2026. The hearing of the abuse applications took place on 9 and 10 February 2026, and the last submissions date recorded in the judgment is 14 January 2026. The present proceeding had been commenced on 13 December 2024. The amendment application was filed on 25 April 2025. The Court recorded that the matter remained at an early stage, with pleadings still open and issues not yet crystallised.

That timing matters. The ruling came before defences and cross-claims had been filed, which underlines how early a procedural challenge can arise in patent litigation. It also reinforces that this decision should be read as an interlocutory ruling about the amendment application, not as a final determination of the underlying infringement dispute.

This page is based on the published Federal Court judgment text for Kutti Bay Investments Pty Ltd v Rattlejack Innovations Pty Ltd [2026] FCA 422. The available text includes the catchwords, orders and substantial parts of the reasons.

However, the available reasons are truncated before the judgment concludes. Because of that, this page focuses on the declaration actually made, the procedural setting, the patent family background, the categories of amendments identified in the available reasons, and the practical significance of the interlocutory ruling. It should not be treated as a complete account of every aspect of the Court's reasoning on every proposed amendment.