Sulzer Mixpac AG v Assistant Controller of Patents and Designs (2026)

Summary

The appellant Sulzer Mixpac AG "filed Application 1329/DEL/2012 on 1 May 2012 before the Controller of Patents for registration of a patent in respect of an invention titled 'Static Mixer'" (para 1). The subject invention "relates to a plastic static mixer with an installation body, which is used to mix molten polymers" and "consists of several installation bodies arranged one behind another" (para 2); "the novel and inventive feature in the subject invention vis-a-vis prior art is, according to the appellant, the ability to connect more than five installation bodies by a common bar element" (para 7). "By order dated 10 March 2021, the ACPD" ("Assistant Controller of Patents and Designs") "rejected the appellant's application dated 1 May 2012" (para 9). The appeal "preferred under Section 117A(2) of the Patents Act, 1970, assailing the said order dated 10 March 2021, stands dismissed by a learned Single Judge of this Court by judgment dated 5 April 2024. The present appeal assails the said judgment." (para 1)

On the respondent's "preliminary objection to the maintainability of the appeal" (para 15), the Bench held that "The ratio decidendi of Promoshirt would apply, mutatis mutandis, to the maintainability of an appeal against an order passed by the ACPD under Section 117A (2) of the Patents Act" (para 20). Of "the five steps enumerated in para 120 of Roche", it held that they "merely provide guidance" and "cannot be regarded as commandments cast in stone" (para 24). On merits it found "the reasoning of the learned ACPD, in the order dated 10 March 2021, to be unexceptionable" (para 26) and held that "the prior art document D1 by itself is sufficient to render the subject invention lacking in inventiveness" (para 32), and that "all that the appellant undertook, while proceeding from its own prior documents D1 to D4, to the subject invention, of which the appellant sought to patent, was a mere modification, using the disclosures and teachings available in prior art documents, of which the main prior art D1 was of the appellant itself" (para 36). Finding "no error in the decision of the learned Single Judge upholding the order of the learned ACPD rejecting the appellant's application for patenting the subject invention", the Bench concluded: "The appeal is accordingly dismissed." (paras 37–38)

What the court decided

1. Maintainability of the Letters Patent Appeal. The respondent submitted "that no Letters Patent Appeal is maintainable against an order passed by the learned Single Judge under Section 117A (2) of the Patents Act" (para 15). Recording that in Promoshirt SM SA v Armasuisse (2023 SCC OnLine Del 5531) the Division Bench held "that the proscription against appeal, under Section 100-A of the CPC" ("Code of Civil Procedure") "was only against orders passed in appeal against an order of the Civil Court" (para 19), the Bench held: "The ratio decidendi of Promoshirt would apply, mutatis mutandis, to the maintainability of an appeal against an order passed by the ACPD" ("Assistant Controller of Patents and Designs") "under Section 117A (2) of the Patents Act." and "We, therefore, reject Mr. Pandey's objection to the maintainability of the present appeal." (paras 15, 19–21)
2. Where the statute adopts the Code. The paragraphs of Promoshirt reproduced by the Bench include: "the LPA" ("Letters Patent Appeal") "remedy would also not be available where the special statute subjects the appeal remedy to follow the rules applicable to appeals and embodied in the Code. Once the appeal is made subject to the rules incorporated in the Code, all restrictions to an appeal including Section 100A would get attracted and attached." (para 19)
3. The Roche steps. The appellant submitted that "in para 120 of its judgment in F Hoffmann-La Roche Ltd v. Cipla Ltd, the Division Bench has outlined five steps which are required to be followed while examining whether the patent under consideration was obvious from prior art, or not" and that, "inasmuch as the learned Single Judge has not followed the above five steps, seriatim, the impugned judgment cannot sustain" (para 22). The Bench held: "Adjudication, under the Patents Act, has to be guided by the statute. To our mind, the five steps enumerated in para 120 of Roche merely provide guidance as to how, in a particular case, the court has to proceed while examining the aspect of inventiveness or obviousness of an invention, which is sought to be patented, vis-à-vis prior art. They cannot be regarded as commandments cast in stone, implicit compliance with which is essential in every case." (paras 22–24)
4. Decision without the steps. "Where the case is capable of being decided without strictly following the rigour of the said five steps, it cannot be said that the decision is vitiated solely on that ground." (para 24)
5. A feature not urged below. "Insofar as the number of streams into which each installation body divides the fluid flow is concerned, that was not even mentioned by the appellant, in its reply to the FER" ("First Examination Report") "or the written submissions filed in response to the SER" ("Subsequent Examination Report") "as constituting the inventive feature of the subject invention. As such, we are not readily inclined to allow the appellant, at this stage, to raise this as a ground." (para 28)
6. Features of the specification. "That apart, the number of streams into which the installation bodies divide the stream is not, even as per the complete specifications of the appellant's patent application, one of the prime features of the subject invention." (para 29)
7. The ACPD's order. The ACPD had held that "D1 itself is a sufficient document to disclose all the technical features of the claimed invention" and that "The applicant has failed to demonstrate any surprising effect in the claimed invention as compared to the teachings in the cited prior arts. Accordingly, the claimed invention is considered not inventive under section 2(1)(ja) of the Patents Act, 1970." (para 11). The Bench found "the reasoning of the learned ACPD, in the order dated 10 March 2021, to be unexceptionable" (para 26) and "the observations of the ACPD to be completely justified" (para 32). (paras 11, 26, 32)
8. A single prior-art document. "In fact, the prior art document D1 by itself is sufficient to render the subject invention lacking in inventiveness." (para 32) "The elements at 14, 15 and 114 and 115 of figure 4 in prior art D1 clearly indicate the existence of a common connection element connecting multiple installation bodies. This diagram, seen in conjunction with paragraphs 71, 74 and 75 of D1 further envisage connection upto 12 installation bodies with one common bar element." (paras 32–33)
9. A reinforced strip for a bar. Of figures 11 and 12 in D3 and figure 1 in D2, the Bench held: "They all indicate multiple installation bodies being connected by one common element. Though the element, in the prior art documents at D3 and D2 are in the nature of a reinforced strip, the use of a bar element in place of reinforced strip would also be obvious to a person skilled in the art." (para 34) and "Drawings 1 and 6 in the prior art document D3 indicate joining of more than five installation bodies using a common bar element." (paras 34–35)
10. The applicant's own prior art. "We have to bear in mind the fact that the aspect of inventiveness has to be seen from the point of view of a person skilled in the art and, especially in a case where the inventor is the same, the leap from prior art to the subject invention is much more easily scaled." (para 32) The ACPD "has also legitimately relied on the fact that the prior art inventions were also of the appellant itself" (para 30), and "It has to be remembered, yet again, that the inventor of D1 and of the subject invention are the same." (paras 30, 32, 34)
11. Mere modification. "Clearly, therefore, all that the appellant undertook, while proceeding from its own prior documents D1 to D4, to the subject invention, of which the appellant sought to patent, was a mere modification, using the disclosures and teachings available in prior art documents, of which the main prior art D1 was of the appellant itself." (para 36) The ACPD had "ultimately rejected the application for patenting the invention solely on the ground that it lacked any inventive step over prior art, as required by Section 2(1)(ja) and was not, therefore, an 'invention' within the meaning of Section 2(1)(j), as it was obvious from prior arts cited as D-1 to D-4" (para 6). (paras 6, 36)
12. The Single Judge's reasoning. The reasoning of the Single Judge, reproduced by the Bench, included that "connectivity has been merely extended by the subject invention to run through all the installation bodies" and that, on "the technical advantages of the said invention in that the pressure loss is lesser", "there is no data which has been provided with respect to prior art Dl-D4 in this regard or a comparative assessment of the functionality element. The only comparison which has been done is with the prior art EP 1426099B1." (para 12). The Bench found "no error in the decision of the learned Single Judge" (para 37). (paras 12, 37)
13. Disposition. "We, therefore, find no error in the decision of the learned Single Judge upholding the order of the learned ACPD rejecting the appellant's application for patenting the subject invention." "The appeal is accordingly dismissed." (paras 37–38)

What the court did not decide

The Bench found it "not necessary for us to enter into all the specifics of the subject invention" (para 6). As to "the number of streams into which each installation body divides the fluid flow", it was "not readily inclined to allow the appellant, at this stage, to raise this as a ground" (para 28).

Subsequent treatment

No later judicial treatment and no further appeal traced as of 16 September 2026.