DCT

2:26-cv-00863

Linton Crystal Tech Corp v. Zhejiang Jingsheng Mechanical & Electrical Co Ltd

Key Events

Amended Complaint

complaint Intelligence

I. Executive Summary and Procedural Information

Parties & Counsel:
- Plaintiff: Linton Crystal Technologies Corp. (Delaware)
- Defendant: Zhejiang Jingsheng Mechanical & Electrical Co., Ltd. (People's Republic of China)
- Plaintiff’s Counsel: Davis Firm, PC; Nixon Peabody LLP
Case Identification: 2:26-cv-00863, E.D. Tex., 09/24/2026
Venue Allegations: Venue is alleged to be proper because the Defendant is not a resident of the United States and may therefore be sued in any judicial district.
Core Dispute: Plaintiff alleges that Defendant’s Czochralski (CZ) crystal-growth pullers infringe two U.S. patents related to seed-lifting mechanisms that convert rotational motion into linear motion.
Technical Context: The technology pertains to mechanical assemblies within crystal-growth furnaces, which are critical for producing the large, high-purity silicon crystals used in the semiconductor and photovoltaic industries.
Key Procedural History: The complaint notes that U.S. Patent No. 11,814,746 is a continuation of the application that resulted in U.S. Patent No. 11,255,024, and that the two patents share a common specification and priority date. This relationship suggests that claim terms may be interpreted consistently across both patents, and that the prosecution history of the parent patent could be relevant to the scope of the continuation patent.

Case Timeline

Date	Event
2019-06-18	Priority Date for '024 and '746 Patents
2022-02-22	U.S. Patent No. 11,255,024 Issued
2023-11-14	U.S. Patent No. 11,814,746 Issued
2024-10-26	Alleged Shipments of Accused Products to U.S. Begin
2026-01-01	Anticipated Deliveries for Texas Project Scheduled
2026-09-24	Complaint Filing Date

II. Technology and Patent(s)-in-Suit Analysis

U.S. Patent No. 11,255,024 - "Seed Lifting and Rotating System for Use in Crystal Growth"

The Invention Explained

Problem Addressed: The patent's background describes conventional crystal growth systems that use a rotating drum to wind a cable, where the drum's translation is achieved via a separate lead screw and nut mechanism. This conventional design is stated to add size, weight, and complexity to the overall system and the lift housing ( Compl. ¶17; ’024 Patent, col. 1:19-44).
The Patented Solution: The ’024 Patent discloses a lift assembly that eliminates the separate lead screw. It uses a "floating roller guide assembly" that directly engages a helical groove on the surface of the cable drum itself. As a drive shaft rotates the drum, the engagement between the drum's groove and the spatially-fixed (but movable or "floating") roller guide forces the drum to translate along its axis, thereby converting rotation into linear motion more compactly ( Compl. ¶¶22-25; ’024 Patent, col. 2:49-4).
Technical Importance: This solution is presented as an improvement that reduces the size, weight, and complexity of seed-lift mechanisms, which are key components in equipment for the photovoltaic and semiconductor industries Compl. ¶17

Key Claims at a Glance

The complaint asserts at least independent Claim 1 Compl. ¶25
Essential elements of Claim 1 include:
- A lift housing forming a cable exit port.
- A drum positioned within the housing, having a helical groove on its exterior surface.
- A "floating roller guide assembly" which itself includes: a mounting plate, a "floating shaft" that is movable relative to the mounting plate, and a "floating roller guide" that is rotationally coupled to the shaft and configured to engage the drum's helical groove.
- A drive shaft that causes the drum to rotate, which in turn causes the drum to translate via its engagement with the floating roller guide.
The complaint's phrasing "at least Claim 1" suggests it reserves the right to assert other claims, including dependent claims Compl. ¶25

U.S. Patent No. 11,814,746 - "Seed Lifting and Rotating System for Use in Crystal Growth"

The Invention Explained

Problem Addressed: As a continuation of the ’024 Patent application, the ’746 Patent addresses the same problem of reducing the size and complexity of seed-lifting mechanisms by eliminating the conventional lead screw and nut (Compl. ¶¶17, 28; ’746 Patent, col. 1:21-48).
The Patented Solution: The ’746 Patent claims a different mechanical configuration to achieve the same goal. In this version, the drum itself is described as being both "rotatable about and translatable along a central axis." This translatable drum engages a "roller guide mounted to the lift housing" which is explicitly "fixed from translating along the central axis." Thus, as the drive shaft rotates the drum, the drum translates along its axis relative to the fixed roller guide (Compl. ¶¶31-32; ’746 Patent, abstract).
Technical Importance: This alternative design is also aimed at creating a more compact and efficient seed-lifting mechanism for crystal growth furnaces Compl. ¶17

Key Claims at a Glance

The complaint asserts at least independent Claim 1 Compl. ¶33
Essential elements of Claim 1 include:
- A lift housing forming a cable exit port.
- A drum positioned within the housing that has a helical groove and is "both rotatable about and translatable along a central axis."
- A roller guide that is mounted to the lift housing, engages the drum's helical groove, and is "fixed from translating along the central axis."
- A drive shaft that causes the drum to rotate, which in turn causes the drum to translate through its engagement with the fixed roller guide.
The complaint's assertion of "at least Claim 1" suggests it reserves the right to assert other claims Compl. ¶33

III. The Accused Instrumentality

Product Identification

The accused products are identified as "JSG CZ crystal-growth pullers," with the "JSG TDR160P-series" specified as an example Compl. ¶36

Functionality and Market Context

The complaint alleges that the Accused Products are used for silicon crystal growth and incorporate seed-lift architectures for lifting and rotating a seed crystal Compl. ¶¶43, 46 It further alleges that JSG markets and supplies these pullers internationally, including for importation into and use in the United States Compl. ¶35
The complaint specifically alleges that different Accused Products incorporate two distinct seed-lift architectures: one that allegedly practices the "floating roller-guide" of the ’024 Patent and another that allegedly practices the "fixed roller-guide" and "translatable drum" of the ’746 Patent Compl. ¶¶53-54 Compl. ¶¶55-60
Linton alleges it competes directly with JSG for customers and projects in the U.S. market for CZ crystal-growth equipment Compl. ¶41 It cites U.S. import records showing shipments of "CZ PULLER" equipment from JSG to U.S. customers and alleges JSG secured a substantial order for a photovoltaic manufacturing project in Texas Compl. ¶¶9, 37, 41

IV. Analysis of Infringement Allegations

No probative visual evidence provided in complaint.

'024 Patent Infringement Allegations

Claim Element (from Independent Claim 1)	Alleged Infringing Functionality	Complaint Citation	Patent Citation
a lift housing forming a cable exit port therein;	The accused seed-lift assembly includes a lift housing that forms a cable exit port.	¶66	col. 6:8-15
a drum positioned within the lift housing, the drum forming a helical groove about an exterior surface of the drum...	The accused assembly includes a drum positioned within the housing, which has a helical groove on its exterior surface.	¶66	col. 6:21-28
a floating roller guide assembly including: a mounting plate...; a floating shaft... movable relative to the mounting plate...; and a floating roller guide rotationally coupled about the floating shaft... configured to engage... the helical groove of the drum;	The accused assembly includes a floating roller-guide assembly with a mounting plate, a floating shaft that is movable relative to the plate, and a floating roller guide that engages the drum's helical groove.	¶67	col. 7:49-65
a drive shaft coupled to the drum and configured to cause (i) the drum to rotate and (ii) a translate via an engagement of the helical groove of the drum with the floating roller guide.	The accused assembly includes a drive shaft. The engagement between the drum's groove and the floating roller guide is alleged to cause the rotating drum to translate along its central axis.	¶68	col. 4:51-64

'746 Patent Infringement Allegations

Claim Element (from Independent Claim 1)	Alleged Infringing Functionality	Complaint Citation	Patent Citation
a lift housing forming a cable exit port;	The accused seed-lift assembly includes a lift housing that forms a cable exit port.	¶47; ¶77	col. 5:48-55
a drum positioned within the lift housing that forms a helical groove about its exterior surface and is both rotatable about and translatable along a central axis;	The accused assembly includes a drum with a helical groove that is configured to both rotate about and translate along a central axis.	¶48; ¶77	col. 2:55-65
a roller guide mounted to the lift housing and rotatable about an axis parallel to and offset from the central axis of the drum, the roller guide engaging at least a portion of the helical groove and being fixed from translating along the central axis;	The accused assembly includes a roller guide that is mounted to the lift housing, rotates about an offset axis, engages the drum's groove, and is fixed from translating along the drum's central axis.	¶49; ¶51; ¶77	col. 2:55-65
a drive shaft coupled to the drum and configured to cause the drum to rotate, such that rotation of the drum causes the drum to translate through engagement between the helical groove and the roller guide.	The accused assembly includes a drive shaft. Rotation of the drum against the fixed roller guide causes the drum to translate along its central axis.	¶52; ¶77	col. 4:51-64

Identified Points of Contention:
- Scope Questions: A central dispute may arise over the structural differences between the claims of the two patents. The ’024 Patent claims a "floating roller guide assembly" where the shaft itself is "movable," while the ’746 Patent claims a "roller guide... being fixed from translating" and a drum that is "translatable." The complaint alleges that JSG's products embody both distinct architectures Compl. ¶¶54, 60 The factual basis for this allegation and the precise mechanical nature of the accused products will be a primary focus.
- Technical Questions: The complaint's allegations regarding the internal mechanics of the accused products are based on "information and belief," "photographs of JSG equipment," and information from knowledgeable persons Compl. ¶55 Compl. ¶66 A key question is what evidence Linton will produce in discovery to prove that the accused products contain either the "floating" guide assembly required by the ’024 Patent or the "fixed guide/translatable drum" architecture required by the ’746 Patent.

V. Key Claim Terms for Construction

The Term: "floating roller guide assembly" (and its component "floating shaft")
- Context and Importance: This term is central to the novelty of the ’024 Patent. The definition of "floating" and "movable" will be critical. Practitioners may focus on this term because the infringement analysis for the ’024 Patent hinges on whether the accused mechanism possesses the specific type of movability required by the claims, as opposed to being fixed or having only incidental mechanical play.
- Intrinsic Evidence for Interpretation:
  - Evidence for a Broader Interpretation: The claim requires the shaft to be "movable relative to the mounting plate in a direction that is generally perpendicular to a central axis of the floating shaft" (’024 Patent, cl. 1). This language could be argued to encompass any degree of designed perpendicular movement.
  - Evidence for a Narrower Interpretation: The specification discloses embodiments where the floating shaft is biased by springs (e.g., 390A, 390B) (’024 Patent, Fig. 4B; col. 7:24-28). A defendant might argue that the term "floating" should be limited to such a biased, self-adjusting configuration rather than any structure that simply permits movement.
The Term: "fixed from translating" (roller guide) vs. "translatable" (drum)
- Context and Importance: These reciprocal terms in Claim 1 of the ’746 Patent define a specific mechanical relationship that is the inverse of a conventional leadscrew. The infringement case for this patent will depend on whether the accused product's components are respectively "fixed" and "translatable" as claimed. The existence of the ’024 Patent with its "floating" guide may be used to argue that the ’746 Patent's "fixed" guide must be strictly non-movable along the axis of translation.
- Intrinsic Evidence for Interpretation:
  - Evidence for a Broader Interpretation (of "translatable" drum): The abstract of the ’746 Patent states that "rotation of the drum causes the drum to translate," supporting the idea that the drum itself is the primary moving part along the central axis.
  - Evidence for a Narrower Interpretation (of "fixed" guide): The plain language of the claim requires the roller guide to be "fixed from translating along the central axis" (’746 Patent, cl. 1). This sets a clear constraint. The contrast with the "floating" guide in the related ’024 Patent provides strong contextual support for interpreting "fixed" to mean substantially immobile along the axis of translation.

VI. Other Allegations

Indirect Infringement: The complaint alleges that JSG induces infringement by supplying Accused Products to U.S. customers and providing "manuals, instructions, technical support, installation assistance, [and] service" that encourage and facilitate the operation of the products in their infringing manner Compl. ¶84 Compl. ¶85
Willful Infringement: Willfulness is alleged based on JSG's continued infringement after acquiring knowledge of the patents, with such knowledge established "at minimum, no later than service of this Complaint" Compl. ¶83 Compl. ¶86 This primarily establishes a basis for post-filing willfulness.

VII. Analyst’s Conclusion: Key Questions for the Case

A core issue will be one of architectural duality: The complaint asserts that Defendant's product line infringes two patents with contrasting mechanical claims—one with a "floating" guide and another with a "fixed" guide. A central factual question for the court will be to determine, through evidence, whether the accused pullers contain one, both, or neither of these specific, and arguably mutually exclusive, seed-lift architectures.
The case will also turn on a question of definitional scope: Given the shared patent specification, the court's construction of the terms "floating" (’024 Patent) versus "fixed from translating" (’746 Patent) will be dispositive. The key legal question is how to define these contrasting limitations and whether the accused product's mechanics fall within the scope of either definition.
Finally, a key evidentiary question will be one of substantiation: The complaint's detailed allegations about the internal workings of the accused products are made "on information and belief." The viability of Linton's case will depend on its ability to produce concrete evidence during discovery that confirms these complex mechanical structures actually exist as alleged.