PTAB

IPR2024-00633

Fluidmaster Inc v. Danco Inc

Key Events

Petition

petition Intelligence

Title: Toilet Fill Valve
Brief Description: The ’993 patent discloses a toilet fill valve system designed to dispense water into a toilet tank and bowl. The system features a water flow regulator that attaches directly to an integrally molded extended portion of the fill valve body, which purportedly prevents the formation of a pressure head in a connecting tube.

Prior Art Relied Upon: Guoxin (CN2447417Y) and Ho (5,862,538).
Core Argument for this Ground:
- Prior Art Mapping: Petitioner argued Guoxin discloses a toilet fill valve system with nearly all claimed features, including a water flow regulator that attaches directly to an extended portion of the valve body. However, Guoxin discloses a "reverse" coupling arrangement where the fill valve has a protrusion and the regulator has a recess. Ho, which was not considered during prosecution, discloses the claimed arrangement: a fill valve body with an integrally molded extended portion containing a recess, into which a regulator with a protrusion is inserted and locked.
- Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would understand that male and female fluid flow connectors are generally interchangeable. A POSITA would combine the teachings by substituting Ho's connector configuration for Guoxin's as a matter of simple design preference to achieve the same function.
- Expectation of Success: The substitution of one well-known coupling arrangement for another would have been a simple and predictable modification with a high expectation of success.

Prior Art Relied Upon: Brown (3,086,546) and Ho (5,862,538).
Core Argument for this Ground:
- Prior Art Mapping: Petitioner asserted that Brown discloses a toilet fill valve system with a water flow regulator in the form of an adjustable set screw attached to an adapter tube (the "extended portion"). To the extent Brown's screw-on adapter tube is not considered "integrally molded," Ho teaches an integrally molded outlet on a fill valve body for attaching a water flow regulator.
- Motivation to Combine: A POSITA would combine the references to update the older design of Brown (filed 1959) with the more modern molding techniques taught by Ho. This would improve the strength, integrity, and ease of assembly of the connection. A POSITA would also be motivated to replace Brown’s set screw with Ho’s diverter valve to simplify operation and adjustment.
- Expectation of Success: Applying modern, well-understood molding techniques and valve designs from Ho to the foundational system of Brown would have led to a predictable and successful improvement.

Prior Art Relied Upon: Schuster (8,104,105).
Core Argument for this Ground:
- Prior Art Mapping: This ground is premised on Petitioner’s argument that the ’993 patent is not entitled to its claimed priority date before January 27, 2014, making Schuster (published 2012) valid prior art under 35 U.S.C. §102. Petitioner contended that Schuster discloses every element of claims 1-20, including a toilet fill valve with an integrally molded extended portion, a bowl fill valve (water flow regulator) configured to attach directly to that extended portion via a snap-fit or locked connection, and a tube attached directly to the regulator.
- Key Aspects: The validity of this ground hinges on the Board accepting Petitioner's argument regarding the patent's effective filing date, which is challenged based on a lack of written description support for key claim terms in the priority applications.
Additional Grounds: Petitioner asserted additional obviousness challenges over Guoxin/Ho and Brown/Ho, further in view of the "Quick Connection Art" (including Bjerke, Calmettes, and Hall), to teach various well-known clamping, snapping, and rotating lock mechanisms for fluid connections recited in dependent claims 3, 4, 6, and 16-18.

"integrally molded": Petitioner proposed this term be construed as "molded together as a single structure or molded separately and subsequently attached to one another to form a single structure." This construction is based on the patent’s own definition of "integral" and is broad enough to read on prior art where parts are attached, not just co-molded.
"water flow regulator": Petitioner proposed this term be construed to include "an adjustable or fixed device for restricting the flow of water." This construction is central to the priority date challenge, as Petitioner argued the priority applications only disclosed adjustable "valves," and the later introduction of a term covering fixed "restrictions" constituted new matter.

Invalid Priority Claim: Petitioner's central technical contention was that the ’993 patent is not entitled to its claimed priority date. It was argued that the patent owner broadened the scope of the invention during prosecution from the originally disclosed adjustable "bowl fill valve" to a "bowl fill restriction" and ultimately to a "water flow regulator," which covers both adjustable valves and fixed restrictors. Petitioner asserted this broadening constitutes new matter not supported by the written description of the earlier applications, making the patent's effective filing date January 27, 2014, at the earliest.

Petitioner argued that discretionary denial would be inappropriate.
- Under §314(a) / Fintiv: The petition asserted that the parallel district court litigation is in its infancy, with a trial date set for June 2025. Petitioner stipulated it would not pursue any IPR grounds in the litigation if review is instituted and stated its intent to file a motion to stay.
- Under §325(d): The petition argued that the primary prior art references (Guoxin, Ho, Schuster) were not considered by the examiner during prosecution. Therefore, the petition raises new arguments and art that are materially different from those previously before the Patent Office.

Petitioner requests institution of an inter partes review and cancellation of claims 1-20 of the ’993 patent as unpatentable.