DCT
3:23-cv-01737
Ruian City Han Sen Technology Co Ltd v. RB Distribution Inc
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Ruian City Han Sen Technology Co. Ltd. (People's Republic of China)
- Defendant: RB Distribution Inc. and Dorman Products, Inc. (Pennsylvania)
- Plaintiff’s Counsel: Ni, Wang & Massand, PLLC
- Case Identification: 3:23-cv-01737, N.D. Tex., 09/20/2023
- Venue Allegations: Plaintiff alleges venue is proper in the Northern District of Texas because the Defendants' actions caused harm to Plaintiff in Texas, which is Plaintiff's largest market, and because Defendants conduct business through interactive websites accessible in the district.
- Core Dispute: Plaintiff seeks a declaratory judgment that its automotive Engine Oil Cooler Filter Housings do not infringe three of the Defendants' patents and that those patents are invalid.
- Technical Context: The technology concerns the design of engine oil filter and cooler assemblies, which are critical components for engine lubrication and are a significant segment of the automotive aftermarket parts industry.
- Key Procedural History: The action was precipitated by an infringement notice sent by Defendant RB through the Amazon Patent Evaluation Express (APEX) Program, which resulted in the delisting of Plaintiff's products. The complaint notes that third parties have filed for ex parte reexamination of all three asserted patents, and the USPTO has granted the request for the ’005 Patent. This introduces a parallel proceeding that could affect the patents' validity and enforceability.
Case Timeline
| Date | Event |
|---|---|
| 2017-09-13 | Dorman prior art YouTube video published |
| 2020-08-21 | Earliest Priority Date for ’005, ’674, and ’675 Patents |
| 2023-04-25 | ’005 Patent Issued |
| 2023-05-02 | ’674 Patent Issued |
| 2023-05-02 | ’675 Patent Issued |
| 2023-07-15 | Plaintiff receives APEX notice alleging infringement |
| 2023-07-15 | Plaintiff's products delisted from Amazon |
| 2023-08-18 | Third-party Request for Ex Parte Reexamination of ’674 Patent filed |
| 2023-08-25 | Third-party Request for Ex Parte Reexamination of ’675 Patent filed |
| 2023-08-29 | USPTO grants Request for Ex Parte Reexamination of ’005 Patent |
| 2023-09-20 | Amended Complaint for Declaratory Judgment filed |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 11,635,005 - "Oil Filter Assembly" (issued April 25, 2023)
The Invention Explained
- Problem Addressed: The patent describes prior art oil filter assemblies, typically made of plastic, as having numerous failure points. These include the use of metallic inserts for attaching components, which can lead to stress cracks in the plastic, and the need for plugs to seal openings left by the molding process, which can leak. (’005 Patent, col. 1:24-58).
- The Patented Solution: The invention is a single, robust "cast metallic" adaptor for the oil filter and cooler assembly. By forming the main body as one piece of metal, it purports to eliminate the need for failure-prone plastic components, inserts, and plugs by enabling components to be threaded directly into the cast body. (’005 Patent, Abstract; col. 2:60-65). This construction is intended to create a more durable, leak-resistant assembly.
- Technical Importance: The design aims to increase the reliability and service life of a critical engine component by replacing a complex, multi-material assembly with a simplified, single-piece metallic structure. (’005 Patent, col. 2:63-65).
Key Claims at a Glance
- The complaint asserts non-infringement of independent claims 1, 5, 6, and 11 (Compl. ¶35).
- Independent Claim 1, a representative claim, requires:
- A "single metallic casting"
- Comprising an elongated body with an oil filter housing at one end and surfaces to mate with an engine's lubrication network and an oil cooler
- An oil lubrication flow path that is "wholly within the elongated body"
- "at least one threaded aperture... formed in the single metallic casting for receiving at least one additional component in a direct threaded engagement with the single metallic casting"
U.S. Patent No. 11,639,674 - "Oil Filter Assembly" (issued May 2, 2023)
The Invention Explained
- Problem Addressed: As a continuation of the application leading to the ’005 Patent, the ’674 Patent addresses the same technical problems of stress, leakage, and failure in prior art plastic and multi-part oil filter assemblies. (’674 Patent, col. 1:25-58).
- The Patented Solution: The invention is also a "one-piece cast metallic adaptor" that provides for direct threading of components. (’674 Patent, Abstract). The solution focuses on creating an "enclosed flow path" for lubricant within a unitary structure, thereby avoiding the seals and plugs required by prior art molding techniques. (’674 Patent, col. 2:1-4).
- Technical Importance: The technical goal is identical to that of the ’005 Patent: to provide a more durable and reliable oil filter assembly by using a monolithic cast metal design. (’674 Patent, col. 2:1-4).
Key Claims at a Glance
- The complaint asserts non-infringement of independent claims 1, and 3-6 (Compl. ¶54).
- Independent Claim 1, as corrected, requires:
- A "unitary metallic casting" defining an integrated structure
- An elongated casted body with surfaces to mate with an engine and an oil cooler, and an oil filter housing at one end
- An "internal lubrication flow path formed within the elongated casted body"
- The elongated casted body includes a "plurality of apertures that are directly threaded in the elongated casted body for mating with a respective threaded component"
U.S. Patent No. 11,639,675 - "Oil Filter Assembly" (issued May 2, 2023)
- Technology Synopsis: This patent is part of the same family and addresses the same deficiencies in prior art oil filter assemblies, such as failures at the junction of plastic and metal parts and leaks from sealing plugs (’675 Patent, col. 1:39-59). The solution is a "one-piece cast metallic adaptor" that integrates threading for components directly into the casting to improve durability and eliminate common failure points (’675 Patent, Abstract).
- Asserted Claims: Independent claims 1, 6, 12, and 17 are at issue (Compl. ¶70).
- Accused Features: Plaintiff's non-infringement argument centers on its product allegedly not being a "single metallic casting" and not using apertures "threaded in the metallic casting" to mate with components, instead using separate bolts (Compl. ¶¶ 71-74).
III. The Accused Instrumentality
Product Identification
- The accused products are the "Somusen Performance Oil Filter Housings," sold by Plaintiff on Amazon and identified by ASINs B0BPSLFPB2 and B09ZDW88R6 (Compl. ¶¶ 8-9, 32).
Functionality and Market Context
- The complaint alleges that the accused products are not a "single casting" but are instead constructed from "multiple parts including the main body and a separate oil cooler" (Compl. ¶36).
- For attachment of components, the complaint alleges the products do not have threaded apertures for direct engagement with a component. Instead, they "use bolts which are used to affix the component to the casting," suggesting the bolts pass through an aperture in the housing to secure a component (Compl. ¶36).
- The complaint states that the Amazon Marketplace is Plaintiff's primary sales channel in the U.S. and that Texas is its top market, highlighting the commercial impact of the product delisting that triggered the lawsuit (Compl. ¶11).
IV. Analysis of Infringement Allegations
This is a declaratory judgment action where the Plaintiff alleges non-infringement. The tables below summarize Plaintiff's primary non-infringement arguments.
’005 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Non-Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| a single metallic casting having... | The accused product is allegedly not a single casting, but rather is constructed from multiple parts, including a main body and a separate oil cooler. | ¶36 | col. 3:40-41 |
| at least one threaded aperture is formed in the single metallic casting for receiving at least one additional component in a direct threaded engagement with the single metallic casting. | The accused product allegedly uses bolts to affix components to the casting, rather than having components engage directly with threads formed in the casting's apertures. | ¶36 | col. 4:50-54 |
’674 Patent Infringement Allegations
| Claim Element (from Independent Claim 1, as corrected) | Alleged Non-Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| a unitary metallic casting that defines an integrated structure having... | The accused product is allegedly not a unitary casting but is made of multiple parts, including a main body and a separate oil cooler. | ¶55 | col. 3:42-43 |
| a plurality of apertures that are directly threaded in the elongated casted body for mating with a respective threaded component. | The product's apertures are allegedly not threaded for mating; instead, the product uses threaded bolts passed through the apertures to affix components. | ¶55 | col. 3:55-58 |
- Identified Points of Contention:
- Scope Questions: A central dispute will be the construction of "single metallic casting" and "unitary metallic casting." The Plaintiff's case rests on these terms meaning a monolithic, one-piece part, which would exclude its allegedly multi-part assembly. The court will need to determine if this construction is supported by the patent's specification and prosecution history.
- Technical Questions: A second key dispute concerns the claimed method of attachment. The patents call for apertures "threaded in the... casting" for "direct... engagement." Plaintiff alleges its product uses bolts passing through unthreaded apertures. The complaint points to Figure 1 of the Gendermann prior art reference, alleging it clearly shows a carrier element defining a filter receiver and receiving an oil cooler as a single continuous structure (Compl. ¶44). The question for the court will be whether the accused product's use of separate bolts is technically distinct from the claimed direct threaded connection.
V. Key Claim Terms for Construction
The Term: "single metallic casting" / "unitary metallic casting"
- Context and Importance: This term is dispositive for infringement. Plaintiff's primary non-infringement argument is that its product is a multi-part assembly, not a "single" or "unitary" casting. The case may turn on whether this term is construed to mean a single, indivisible piece of metal formed in one casting process.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The complaint does not provide specific detail for analysis of potential broader interpretations. A defendant might argue the term refers to the primary functional body being a single casting, even if other non-essential parts are attached.
- Evidence for a Narrower Interpretation: The patents' abstracts and summaries repeatedly emphasize the "single" and "one-piece" nature of the invention as the solution to problems in prior art multi-part assemblies. The ’005 Patent summary explicitly highlights the benefit of "eliminating the assembly of multiple molded parts" (’005 Patent, col. 2:63-64).
The Term: "direct threaded engagement with the single metallic casting"
- Context and Importance: This term defines how components are attached. Plaintiff alleges its product uses bolts, which it argues is not a "direct threaded engagement." Practitioners may focus on this term because if "direct engagement" requires the external component's threads to mate with threads that are an integral part of the casting wall, Plaintiff's use of a separate bolt as a fastener may not infringe.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The complaint does not provide specific detail for analysis of potential broader interpretations. A defendant could argue that using a bolt to secure a component to the casting constitutes a form of "direct... engagement" between the component and the casting.
- Evidence for a Narrower Interpretation: The patents contrast the invention with prior art that required separate "metallic insert[s]" (’005 Patent, col. 1:40-42). The specification states the invention "provides for direct threading of components to the adaptor," which suggests the threads are integral to the adaptor itself, not supplied by a separate fastener (’005 Patent, col. 2:61-63).
VI. Other Allegations
- Indirect Infringement: The complaint seeks a declaration of non-infringement, both directly and indirectly, but does not allege facts related to inducement or contributory infringement, as it is a defensive pleading (Compl. ¶42).
- Willful Infringement: This is not applicable, as the complaint does not allege infringement by the Defendants.
VII. Analyst’s Conclusion: Key Questions for the Case
- A core issue will be one of definitional scope: can the terms "single metallic casting" and "unitary metallic casting", which the patents present as a solution to failures in multi-part assemblies, be construed to cover Plaintiff's allegedly multi-part oil filter housing? The outcome of this claim construction will be pivotal.
- A second central question is one of technical mechanism: does the accused product's alleged use of separate bolts passing through apertures to secure components fall within the scope of the claims' requirement for "direct threaded engagement with the... casting", or is this a fundamentally different and non-infringing method of attachment?
- A significant procedural question looms over the entire case: what will be the effect of the ongoing ex parte reexaminations? The complaint heavily asserts invalidity based on numerous prior art references (Compl. ¶¶ 44-50, 62-66, 77-80). A final decision from the USPTO invalidating the asserted claims could render the infringement analysis moot and terminate the controversy.