Robert Bosch Limited, filed an appeal before the Madras High Court, challenging the rejection of their Indian Patent Application No. 201944047460. The application, titled “Method of Preheating and Controlling the Temperature of Fuel Injected into a Combustion Engine,” was refused by the Deputy Controller of Patents and Designs on the ground that the invention fell under the exclusions listed in Section 3(m) of the Patents Act.

The application initially underwent examination, and the First Examination Report (FER) dated 14.10.2020 raised objections based on lack of novelty and inventive step with reference to prior art documents D1 and D2. The FER also cited Section 3(d), excluding claims 1 to 6 from patentability. In response, the applicant submitted detailed responses and attended multiple hearings. Notably, the hearing notice dated 02.01.2023 maintained objections regarding inventive step but made no mention of Section 3(m). After a final hearing on 30.01.2023 and post-hearing written submissions on 13.02.2023, the impugned order was issued on 07.08.2023, rejecting the application solely on the ground that it was not patentable under Section 3(m).

Counsel for the appellant argued that the Controller erred in applying Section 3(m) to the claimed invention. It was submitted that the claimed invention was not a mere abstract idea or mental act but involved a specific and detailed method with real-world application. The method used hardware elements – such as fuel-heating devices, sensors, and control units – to control the temperature of fuel being injected into a combustion engine. Thus, the claim was clearly a technical process and not theoretical in nature.

The appellant highlighted that the invention involved a sequence of steps implemented through mechanical and electrical components and should therefore be treated as a process claim, which is well within the scope of patentable subject matter under the Patents Act. Furthermore, the refusal under Section 3(m) came as a surprise since previous communications only raised objections related to inventive step, and no hearing or opportunity was provided specifically to address the Section 3(m) objection.

The counsel for the Patent office defended the impugned order, stating that the invention described a method and did not result in the creation of a tangible product. According to the respondent, the method outlined in the application was theoretical in nature and did not involve any modification to the existing engine. It was argued that since no new part was developed and no product emerged from the method, the claim amounted to a mere scheme or instruction manual and was thus excluded from patentability under Section 3(m).

The Court closely examined the independent claim 1 of the patent application. The claim detailed a method involving:
• Measurement of ambient and fuel temperatures,
• Calculation of required heating power,
• Application of that power via control units and heating devices, and
• Sequential comparisons and adjustments to optimize fuel temperature before starting the engine.

The Court found that the method outlined involved a well-defined sequence of operations executed through a combination of sensors, controllers, and heating units. The involvement of tangible components and the method’s practical application within an engine control system negated the characterization of the invention as a mere mental act.

Section 3(m) of the Patents Act excludes “a mere scheme or rule or method of performing mental act or method of playing game” from patentability. The Court held that if the interpretation of Section 3(m) adopted by the respondent were to be accepted, it would result in the exclusion of all process or method claims, which is contrary to the scheme of the Patents Act that clearly allows both product and process patents.

The Court also took note that in the hearing notice issued earlier, the only objection maintained was lack of inventive step, and there was no reference to Section 3(m). Therefore, the Controller’s refusal on a new objection without prior notice or opportunity to respond violated principles of natural justice.

Accordingly, the Court set aside the impugned order of the patent office, holding that the claimed invention does not fall within the scope of Section 3(m) and that the refusal lacked procedural fairness.

The Court remanded the matter for fresh consideration on the following terms:
• The re-examination shall be conducted by a different officer to avoid any perception of bias or pre-determination.
• The reconsideration must focus only on the other objections previously maintained (such as lack of inventive step), and not on Section 3(m).
• A reasoned decision must be issued within four months after providing the appellant a fair opportunity to present their case.

The Court clarified that it made no findings on the merits of the patent application beyond the issue of Section 3(m).

This decision reinforces that method or process claims are very much within the ambit of patentable subject matter under Indian patent law, provided they involve a technical application and are not mere abstract or mental acts. The judgment is also a reminder that patent refusals must be grounded in sound reasoning and should strictly adhere to procedural fairness, including giving applicants an opportunity to address all grounds of rejection. By setting aside the refusal and directing a fresh hearing, the Court has upheld both the substantive and procedural safeguards enshrined in the Patents Act.

• Case Title: Robert Bosch Limited v. Deputy Controller of Patents and Designs
• Case No.: CMA(PT)/1/2024
• Court: High Court of Judicature at Madras
• Presiding Judge: Hon’ble Mr. Justice Senthilkumar Ramamoorthy
• Date of Judgment: 25 March 2025