Flsmidth Inc v. Metso Finland Oy formerly Known As Metso OutoTec Finland Oy

1. Case Identification

• Case #: IPR2025-00985
• Patent #: 9,518,604
• Filed: May 14, 2025
• Petitioner(s): FLSmidth Inc.
• Patent Owner(s): Metso Outotec (Finland) Oy
• Challenged Claims: 1-26

2. Patent Overview

• Title: Fluid Bearings
• Brief Description: The ’604 patent relates to fluid bearings used to support a radial load from a rolling body, such as in a grinding mill. The invention purports to improve on prior art bearings by using a polymer bearing pad instead of a traditional metal pad and discloses various means for fastening the pad to a bearing base.

3. Grounds for Unpatentability

Ground 1: Obviousness over GB384 and DE364 - Claims 1-5, 7, 10-15, 17, 20-22, and 25-26 are obvious over GB384 in view of DE364.

• Prior Art Relied Upon: GB384 (U.K. Patent No. GB1508384) and DE364 (German Publication No. DE102007039364).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that GB384 discloses a bearing assembly for a grinding mill comprising all key structural elements of independent claim 1, including a frame, a plurality of fluid bearings (shoes), a base, and an anti-friction lining with at least one recess and fluid passage. GB384, however, does not specify the material of its "anti-friction lining." DE364 expressly teaches a bearing assembly with a polymer bearing pad, fasteners with passages for lubricant, and the option for the pad to be made in sections. Petitioner contended that substituting the generic anti-friction lining of GB384 with the specific polymer material taught by DE364 renders the claims obvious.
  • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine the references to improve the bearing of GB384. DE364 teaches that polymers improve "sliding properties" and provide favorable stability and stiffness. A POSITA would have recognized this as a solution to the "shearing stress" problem identified in GB384, seeking to decrease friction and improve lubrication stability.
  • Expectation of Success: A POSITA would have had a reasonable expectation of success, as using polymers for bearing pads was a known technique to address the known problem of friction and wear in mechanical systems.

Ground 2: Obviousness over '133 Patent and DE364 - Claims 1-5, 7, 10-15, 17, and 20 are obvious over the '133 patent in view of DE364.

• Prior Art Relied Upon: Cornford (’133 patent, Patent 4,025,133) and DE364.
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner asserted that the '133 patent discloses a bearing assembly for supporting a journal with a frame, a plurality of fluid bearings ("shoe members"), and a bearing liner with oil grooves (recesses) supplied by a pressure fluid circuit. Like GB384, the '133 patent does not identify the composition of its bearing liner. The combination with DE364, which teaches a polymer bearing pad, was argued to render the claims obvious. The '133 patent discloses a self-adjusting bearing via a pivotal mounting, satisfying claim 1, while Petitioner argued that using a fixed bearing (for claim 11) was a known design alternative.
  • Motivation to Combine: The motivation is similar to Ground 1. A POSITA would incorporate the polymer pad from DE364 into the system of the '133 patent to gain the known advantages of polymers, such as reduced friction and improved wear resistance. DE364 also teaches using fasteners for a replaceable "wear part," which a POSITA would be motivated to use to simplify maintenance of the '133 patent's bearing.
  • Expectation of Success: The combination represents the application of a known material (polymer) and a known maintenance strategy (replaceable pads) to a conventional bearing system, leading to a high expectation of success.

Ground 3: Obviousness over Metso, '993 Publication, and Trygg - Claims 1 and 11 are obvious over Metso, the '993 publication, and Trygg.

• Prior Art Relied Upon: Metso (Metso Brochure No. 2060 02-02), the '993 publication (Application # 2012/0099993), and Trygg (a CIM article).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued Metso discloses a fixed-mount hydrostatic bearing for a grinding mill with a pad, base, recess, and fluid passageway. The '993 publication teaches the advantages of using multiple polymer bearing pads in a hydrostatic bearing, noting their favorable stability, low friction, and ability to deform slightly under pressure to build a better fluid film. Trygg explicitly discusses the design choice between fixed-mounted and self-aligning fluid bearings for grinding mills.
  • Motivation to Combine: A POSITA would combine the teachings of the '993 publication with the Metso bearing to gain the well-documented performance advantages of polymer pads. Further, a POSITA would consult a reference like Trygg to select between a fixed mount (as in Metso, for claim 11) or a self-adjusting mount (for claim 1) based on the specific engineering needs of the application, representing a simple design choice.
  • Expectation of Success: The combination involves applying known materials and predictable design alternatives to a standard bearing system, and thus a POSITA would have had a high expectation of success.
• Additional Grounds: Petitioner asserted additional obviousness challenges based on the combination of GB384 and DE364 with further single references (’799 patent, ’551 patent, and Trygg) to address specific dependent claims related to chamfers, lateral connectors, and fluid passages.

4. Key Claim Construction Positions

• Petitioner contended that while no explicit constructions were required, the terms "mounting element" and "locking element" are means-plus-function terms subject to 35 U.S.C. §112(f). As such, they should be construed to cover the corresponding structures described in the ’604 patent's specification and their equivalents.

5. Key Technical Contentions (Beyond Claim Construction)

• Petitioner asserted that several key technologies were part of the general knowledge of a POSITA. This included the understanding that polymers were a well-known and advantageous material for bearing surfaces due to their low coefficient of friction.
• It was also argued to be common knowledge that the choice between a "fixed" and a "self-aligning" bearing was a routine engineering design choice based on predictable trade-offs related to load characteristics, complexity, and cost.

6. Arguments Regarding Discretionary Denial

• Petitioner argued that discretionary denial under 35 U.S.C. §325(d) would be inappropriate. Although the primary reference GB384 was cited during prosecution, Petitioner asserted that the Examiner materially erred by failing to substantively analyze or apply its teachings against claims 1-20. The Examiner's analysis was limited to what became claim 21, thus overlooking clear teachings relevant to the patentability of the remaining claims.

7. Relief Requested

• Petitioner requests institution of an inter partes review and cancellation of claims 1-26 of the ’604 patent as unpatentable.