Fluidmaster Inc v. Danco Inc

1. Case Identification

• Case #: IPR2017-00770
• Patent #: 8,943,620
• Filed: January 26, 2017
• Petitioner(s): Fluidmaster, Inc.
• Patent Owner(s): Danco, Inc.
• Challenged Claims: 1-4, 11-13, 20-25, and 29

2. Patent Overview

• Title: Dual Flush Toilet Conversion Kit
• Brief Description: The ’620 patent discloses an apparatus and method for retrofitting a standard toilet with a dual-flush capability. The invention comprises a flush mechanism, a gasket, and an adapter assembly that secures to the toilet's existing overflow tube and flush valve orifice.

3. Grounds for Unpatentability

Ground 1: Anticipation of All Challenged Claims - Claims 1-4, 11-13, 20-25, and 29 are anticipated by Tedei.

• Prior Art Relied Upon: Tedei (Patent 4,110,850).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Tedei, a 1978 patent for a dual-flush retrofit assembly, discloses every limitation of the challenged claims. Tedei teaches a flush mechanism (valve body 20) with two separate flappers (80, 82) that provide predefined full and reduced flush capabilities, satisfying the limitations of independent apparatus claim 1 and dependent claim 2. Tedei's gasket (70) is detachably attached via a "circular support member" or adaptor (54) to form a seal with the drain valve (16), which is maintained during a flush. The flush valve is configured to seat the flappers as sealing members. For the method claims, Petitioner asserted that Tedei’s purpose as a retrofit kit inherently teaches the claimed method steps of removing an old sealing member and installing the new assembly.
  • Key Aspects: Petitioner contended that Tedei discloses specific dependent claim features, including a clamp (collars 32, 46) to engage the overflow tube (claim 3), a rotatably coupled canister (valve body 20 rotates on adaptor 54) (claim 12), and an angled flush orifice (claim 20).

Ground 2: Obviousness of Select Claims - Claims 11, 12, 21-25, and 29 are obvious over Tedei in view of Homeowners and Galowin.

• Prior Art Relied Upon: Tedei (Patent 4,110,850), Homeowners (a 2004 Sterling toilet manual), and Galowin (a 2002 symposium article).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground was presented as an alternative to Ground 1, addressing a potentially narrower construction of the term "dual flush canister." Petitioner argued that even if Tedei's dual-flapper system does not meet the definition of a "canister," a person of ordinary skill in the art (POSITA) would have found it obvious to replace Tedei's dual-flapper mechanism with the modern, more efficient dual-flush "canister" taught by Homeowners. Homeowners explicitly discloses a dual-flush canister that can be easily removed and installed in an existing toilet. The resulting combination would be Tedei's mounting and sealing structure (adaptor, gasket, clamps) used to install the Homeowners canister, thereby teaching all limitations of the challenged claims.
  • Motivation to Combine: The primary motivation was to improve water efficiency and reduce leakage. Galowin taught that drop-valves (such as the canister in Homeowners) are superior to the flapper valves used in Tedei because they provide a better seal and more consistent flush volumes. A POSITA would therefore be motivated to substitute the known, superior canister from Homeowners into the Tedei retrofit system to achieve the predictable benefits of improved performance and water conservation.
  • Expectation of Success: Petitioner argued a POSITA would have a high expectation of success. The combination was a simple substitution of one known flush mechanism for another. Homeowners provides instructions for simple installation, and any necessary sizing modifications to mate the canister with Tedei's existing components would have been a matter of routine skill.

4. Key Claim Construction Positions

• "dual flush canister": Petitioner’s arguments were structured to address multiple potential constructions of this term.
  • For its anticipation ground (Ground 1), Petitioner implicitly argued for a broad construction where Tedei’s "tubular member" valve body (20) and its associated flappers constitute a "dual flush canister."
  • For its obviousness ground (Ground 2), Petitioner argued that even under a narrower construction limited to modern drop-valve style canisters, the claims are obvious by combining Tedei with a reference (Homeowners) that explicitly discloses such a device.

5. Arguments Regarding Discretionary Denial

• Petitioner argued that the primary prior art reference, Tedei, was never analyzed, described, or cited during the original prosecution of the ’620 patent. This suggests that the Patent Office had not previously considered the most pertinent art, weighing against a potential discretionary denial under 35 U.S.C. §325(d).

6. Relief Requested

• Petitioner requests institution of an inter partes review and cancellation of claims 1-4, 11-13, 20-25, and 29 of the ’620 patent as unpatentable.