Henrob Ltd v. Newfrey LLC

1. Case Identification

• Case #: IPR2019-00269
• Patent #: 9,803,675
• Filed: November 12, 2018
• Petitioner(s): Henrob Ltd.
• Patent Owner(s): Newfrey LLC
• Challenged Claims: 1-12

2. Patent Overview

• Title: Self-piercing rivet and self-piercing riveting method and self-piercing riveted joint
• Brief Description: The ’675 patent discloses self-piercing rivets designed for connecting high-strength steel sheets. The invention focuses on specific rivet geometries, particularly a relatively small axial recess depth, to provide greater stability and prevent fracturing when piercing high-strength materials.

3. Grounds for Unpatentability

Ground 1: Anticipation over Kamata - Claims 1-2, 5-7, and 9-11 are anticipated by Kamata.

• Prior Art Relied Upon: Kamata (WO 2006/087984).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Kamata, which was not considered during prosecution, explicitly discloses a self-piercing rivet for fastening hard steel sheets with a shallow recess. Petitioner contended that Kamata’s Examples 3.2 and 3.3 disclose every limitation of the challenged independent claims 1 and 9. Critically, Petitioner asserted that Kamata teaches a rivet where the ratio of the axial recess depth to the shank diameter is smaller than the claimed 0.3 threshold. This ratio was the sole reason for allowance cited by the USPTO examiner. Petitioner provided calculations based on dimensions given in Kamata, arguing that its Example 3.3 shows a ratio of 0.2, and its Example 3.2 shows a ratio of either 0.22 or 0.28 depending on the assumed manufacturing drill bit angle. Kamata also allegedly discloses the dependent claim features, such as a frustoconical recess (claim 2) and specific volume/width ratios (claims 6, 7, 10, 11).

Ground 2: Obviousness over Kamata, Todd, and Nozaki - Claims 2, 5, and 9-11 are obvious over Kamata in view of Todd and Nozaki.

• Prior Art Relied Upon: Kamata (WO 2006/087984), Todd (Manufacturing Processes Reference Guide, 1994), and Nozaki (Japanese Patent Application H-09-317730).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground asserted that even if Kamata does not explicitly disclose a frustoconical or non-cylindrical recess as required by claims 2, 5, and 9, these features were well-known design choices. Nozaki was cited for its teaching of a self-piercing rivet with a frustoconical-shaped axial recess to improve joint strength by facilitating the spreading of the rivet shank. Todd was cited as a general manufacturing reference teaching standard drill bit point angles (118° to 135°) for drilling steel, providing a basis for calculating the maximum recess depth in Kamata if its explicit disclosure was deemed insufficient.
  • Motivation to Combine: A POSITA would combine Kamata with Nozaki to gain the known benefits of a frustoconical recess—namely, increased joining strength—as taught by Nozaki. Kamata itself suggests that its recess is not limited to a straight hole and may be a "tapered hole," directing a POSITA to consider known shapes like the one in Nozaki. A POSITA would consult a standard reference like Todd for appropriate drill bit angles to manufacture the recess described in Kamata.
  • Expectation of Success: The combination involved applying a known recess shape (from Nozaki) to a known type of rivet (from Kamata) to achieve a predictable improvement in joint strength. The result was merely the predictable use of prior art elements according to their established functions.

Ground 3: Anticipation over Reinstettel - Claims 1, 3, and 5-8 are anticipated by Reinstettel.

• Prior Art Relied Upon: Reinstettel (dissertation attachment, "Laboratory test for the process stability at rivet-clinching," 2013).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Reinstettel, a dissertation attachment also not before the examiner, discloses a self-piercing steel rivet made by Henrob that anticipates the claims. Petitioner asserted that drawings in Reinstettel show a rivet with all the structural features of claim 1. To demonstrate the critical ratio of recess depth to shank diameter of less than 0.3, Petitioner used the dimensions provided in Reinstettel's figures to create a CAD model, from which it calculated an axial depth yielding a ratio of 0.08. Petitioner further argued that Reinstettel’s figures show an "arch-shaped" and non-cylindrical recess (claims 3 and 5), and calculations based on the CAD model show the claimed recess volume and radial width ratios (claims 6 and 7). Finally, Reinstettel allegedly discloses a steel rivet with a hardness of "555 ± 25 Hv," satisfying the hardness limitation of at least 500 HV10 (claim 8).
• Additional Grounds: Petitioner asserted numerous other grounds, including that claims 1 and 6 are obvious over Kamata and Todd; claim 3 is obvious over Kamata and Klaus; claim 4 is obvious over Kamata and Trinick; claim 8 is obvious over Kamata, Todd, and Trinick; claim 12 is obvious over Kamata, Todd, Nozaki, and Trinick; claims 2 and 9-12 are obvious over Reinstettel and Nozaki; and claim 4 is obvious over Reinstettel and Trinick. These grounds relied on similar arguments, substituting prior art references to teach known alternative features like arch-shaped recesses (Klaus) or pointed-arch recesses and high hardness values (Trinick).

4. Key Claim Construction Positions

• "for connecting high-strength steels": Petitioner argued this preamble term is a non-limiting statement of purpose. Alternatively, if found to be limiting, it should be construed as "capable of connecting high strength steel."
• "frustoconical in longitudinal [cross] section": Petitioner proposed this means "a lengthwise section of the recess has the shape of the basal or part of a solid cone formed by cutting off the top by a plane parallel to the base." This construction was central to applying prior art like Nozaki.
• "between 0.25 and 0.05": For ratio limitations in claims 10 and 11, Petitioner argued this phrase should be construed to include the endpoints (i.e., less than or equal to 0.25 and greater than or equal to 0.05), which was critical for showing that calculated ratios from the prior art (e.g., 0.055) fell within the claimed range.

5. Relief Requested

• Petitioner requested the institution of an inter partes review and cancellation of claims 1-12 of the ’675 patent as unpatentable.