DCT

5:25-cv-00192

Higher Power Hydraulic Doors LLC v. Fehr's Metal Building Construction LP

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 5:25-cv-00192, N.D. Tex., 09/15/2025
  • Venue Allegations: Plaintiff alleges venue is proper because Defendant is a Texas entity, resides in Texas for venue purposes, and regularly transacts business with customers within the Northern District of Texas.
  • Core Dispute: Plaintiff alleges that Defendant’s tilt-up door products infringe eight patents related to the mechanical and hydraulic systems for operating large, single-panel doors.
  • Technical Context: The technology relates to mechanical and hydraulic lift systems for large, single-panel "tilt-up" doors used in buildings such as aircraft hangars and agricultural storage facilities, where wide openings are required.
  • Key Procedural History: Plaintiff alleges it sent a notice letter to Defendant regarding the infringement on March 26, 2025, to which Defendant allegedly did not respond. Plaintiff also alleges its own products are marked with the patent numbers at issue.

Case Timeline

Date Event
2009-06-23 Priority Date for all Patents-in-Suit
2012-08-21 U.S. Patent No. 8,245,446 Issues
2013-09-24 U.S. Patent No. 8,539,716 Issues
2014-07-08 U.S. Patent No. 8,769,871 Issues
2015-04-28 U.S. Patent No. 9,015,996 Issues
2015-07-28 U.S. Patent No. 9,091,107 Issues
2016-08-02 U.S. Patent No. 9,404,301 Issues
2016-08-30 U.S. Patent No. 9,428,951 Issues
2019-02-19 U.S. Patent No. 10,208,529 Issues
2025-03-26 Plaintiff sends notice letter to Defendant
2025-09-15 Complaint Filed

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

U.S. Patent No. 8,245,446 - "Tilt-up Door"

The Invention Explained

  • Problem Addressed: The patent’s background section notes that conventional sectional overhead doors used for very wide openings (e.g., 15-25+ feet) are prone to sagging in the middle when opened, while single-panel doors require significant truss support to prevent such sagging (Compl. ¶1; ’446 Patent, col. 1:19-28).
  • The Patented Solution: The invention is a lifting mechanism for a single-panel tilt-up door. The system uses vertical channel members on either side of the door opening. Carriages, to which the door is pivotally attached, move vertically within these channels. As an actuator lifts the carriages, cam followers attached to the top of the door engage with curved cam surfaces on horizontal tracks, causing the door to tilt from a vertical closed position to a horizontal open position ('446 Patent, Abstract; col. 3:23-4:21).
  • Technical Importance: This design provides a structured and robust lifting mechanism for very large, single-panel doors used in applications like aircraft hangars, distributing the load and controlling the door's path of motion during operation ('446 Patent, col. 1:12-18).

Key Claims at a Glance

  • The complaint asserts independent claim 1 (Compl. ¶36).
  • Essential elements of claim 1 include:
    • A tilt-up door for a building opening.
    • A door frame with horizontal and vertical members, including pivot shaft tubes and outwardly extending cam followers.
    • First and second vertical, U-shaped channel members connected to the building.
    • First and second horizontal track members with a curved cam surface.
    • First and second carriages with wheels, positioned for vertical movement in the U-shaped channels.
    • Horizontally extending pivot shafts connecting the pivot shaft tubes to the carriages.
    • A horizontally extending truss on the outside of the door.
    • At least one actuator to move the carriages.
    • The door is mounted for both vertical and tilting movement as the actuator moves the carriages and the cam followers engage the cam surfaces.
  • The complaint reserves the right to assert additional claims (Compl. ¶36).

U.S. Patent No. 8,539,716 - "Tilt-up Door"

The Invention Explained

  • Problem Addressed: The patent addresses the same technical challenge as the ’446 Patent: providing a reliable opening mechanism for large, heavy, single-panel doors for buildings like airplane hangars and farm equipment storage ('716 Patent, col. 1:12-25).
  • The Patented Solution: This invention refines the tilt-up door system by defining a specific geometry for the cam surface. The cam surface has three distinct segments: "a first steep inclined segment, a second inclined segment and a third descending segment." This sequence of cam surfaces dictates a precise path of motion: an initial vertical lift, followed by an inward rotation, and concluding with the door settling into its final raised position ('716 Patent, Abstract; col. 1:33-51).
  • Technical Importance: The defined multi-segment cam path allows for more controlled door motion, where the initial vertical lift is particularly noted as an advantage for clearing material like snow or ice from the base of the door before the tilting motion begins ('716 Patent, col. 8:35-41).

Key Claims at a Glance

  • The complaint asserts independent claim 1 (Compl. ¶44).
  • Essential elements of claim 1 include:
    • A tilt-up door system.
    • A door frame with vertically juxtaposed members defining a vertical track.
    • At least one first cam surface with three specific segments: a first steep inclined segment, a second inclined segment, and a third descending segment.
    • A door sized to span the opening, pivotally coupled with a roller in the vertical track and a cam follower for the cam surface.
    • A motive force that causes the cam follower to abut each of the three segments in sequence to move the door from a closed to an open position.
  • The complaint reserves the right to assert additional claims (Compl. ¶44).

Multi-Patent Capsules

  • U.S. Patent No. 8,769,871 ("’871 Patent"), “Tilt-up Door,” issued July 8, 2014.

    • Technology Synopsis: This patent describes a tilt-up door system with vertical "juxtaposed members," "curved cam surfaces," and a door with "pivot shaft tubes" and "cam followers." An actuator moves carriages vertically, causing the cam followers to move along the cam surfaces and tilt the door open (Compl. ¶52).
    • Asserted Claims: Independent claim 1 (Compl. ¶52).
    • Accused Features: The accused features include the overall mechanical structure of the door, its frame, lifting carriages, and cam mechanism (Compl. ¶52).

  • U.S. Patent No. 9,015,996 ("’996 Patent"), “Tilt-up Door,” issued April 28, 2015.

    • Technology Synopsis: This patent builds on the tilt-up door system by specifying the actuator as comprising "vertically extending first and second hydraulic cylinders." The operation involves these hydraulic cylinders moving the carriages vertically to open the door (Compl. ¶60).
    • Asserted Claims: Independent claim 1 (Compl. ¶60).
    • Accused Features: The allegations target the accused door's mechanical lift system, specifically identifying its use of hydraulic cylinders as the actuator (Compl. ¶60(h)).

  • U.S. Patent No. 9,091,107 ("’107 Patent"), “Tilt-up Door,” issued July 28, 2015.

    • Technology Synopsis: This patent focuses on the hydraulic system that drives the tilt-up door. It claims a combination of mechanical door components with a specific hydraulic actuator system that includes hydraulic cylinders with a "supply port, a flow control valve connected to the supply port, and a solenoid check valve," all connected via a "hydraulic circuit" to a pump, motor, and fluid tank (Compl. ¶68).
    • Asserted Claims: Independent claim 1 (Compl. ¶68).
    • Accused Features: The allegations target the accused product's complete hydraulic system, including its hydraulic cylinders, valves, pump, motor, and hydraulic circuit (Compl. ¶68(g)-(i)).

  • U.S. Patent No. 9,404,301 ("’301 Patent"), “Tilt-up Door,” issued August 2, 2016.

    • Technology Synopsis: This patent describes the vertical guide members of the tilt-up door system as "juxtaposed channel members each having a web and first and second spaced flanges forming a generally U-shaped channel." The carriages, featuring at least two wheels, are arranged for vertical movement within this U-shaped channel (Compl. ¶76).
    • Asserted Claims: Independent claim 1 (Compl. ¶76).
    • Accused Features: The allegations focus on the structural "U-shaped channel" guides and the corresponding wheeled carriages of the accused door system (Compl. ¶76(b), (d)).

  • U.S. Patent No. 9,428,951 ("’951 Patent"), “Tilt-up Door,” issued August 30, 2016.

    • Technology Synopsis: Similar to the ’716 Patent, this patent specifies a cam geometry with three segments: "a first steep inclined segment, a second inclined segment and a third generally horizontal segment." The system is actuated by hydraulic cylinders that move carriages vertically (Compl. ¶84).
    • Asserted Claims: Independent claim 1 (Compl. ¶84).
    • Accused Features: The allegations target the combination of the accused door's specific three-segment cam mechanism and its hydraulic actuation system (Compl. ¶84(c), (g)).

  • U.S. Patent No. 10,208,529 ("’529 Patent"), “Tilt-up Door,” issued February 19, 2019.

    • Technology Synopsis: This patent claims a system where "generally horizontal members" extend from the vertical tracks and have the "first cam surface" on them. The door has cam followers that engage this surface. The system is driven by hydraulic cylinders moving carriages along the vertical tracks (Compl. ¶92).
    • Asserted Claims: Independent claim 1 (Compl. ¶92).
    • Accused Features: The allegations focus on the accused product's use of separate horizontal members with cam surfaces, in combination with its vertical tracks, carriages, and hydraulic actuators (Compl. ¶92(c)).

III. The Accused Instrumentality

Product Identification

  • The complaint identifies the accused instrumentality as a "tilt-up door product" made, used, sold, or offered for sale by Defendant FMBC (Compl. ¶26).

Functionality and Market Context

  • The complaint alleges the Accused Product is a large, single-panel door used for buildings such as airplane hangars and farm equipment storage buildings (Compl. ¶31). The complaint alleges that photographs attached as Exhibit I illustrate the Accused Product (Compl. ¶26). One such installation is identified at Odessa-Schlemeyer Field in Odessa, Texas (Compl. ¶27). The functionality of the accused product is alleged to include all the mechanical and hydraulic features recited in the asserted claims, including a door frame, vertical guide channels, carriages, cam followers, cam surfaces, and hydraulic actuators that work together to lift and tilt the door from a closed to an open position (Compl. ¶¶36, 44, 52, 60, 68, 76, 84, 92).

IV. Analysis of Infringement Allegations

U.S. Patent No. 8,245,446 Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
a door frame including at least top and bottom horizontal members, at least two vertical side members...each of the at least two vertical side members having a horizontally extending pivot shaft tube...and first and second horizontal outwardly extending cam followers... The Accused Product has a door frame with these specified members, including pivot shaft tubes and cam followers. ¶36(b) col. 3:45-56
first and second vertical channel members each having a web and spaced flanges forming a generally U-shaped channel... The Accused Product has first and second vertical channel members with a U-shaped cross-section. ¶36(c) col. 3:35-41
first and second generally horizontal track members...each horizontal track member having a curved cam surface... The Accused Product has horizontal track members with a curved cam surface. ¶36(d) col. 7:34-54
first and second carriages each including a horizontal pivot shaft journal and at least two wheels, each of the carriages being positioned in one of the U-shaped channels for vertical movement... The Accused Product has first and second carriages with journals and wheels that move vertically in the U-shaped channels. ¶36(e) col. 5:1-15
a horizontally extending truss on the outside of the door...to be outside the door opening when the door is in the open position... The Accused Product has a horizontally extending truss on its exterior, positioned to be outside the opening when the door is open. ¶36(g) col. 3:42-45; 4:4-21
at least one actuator connected to the first and second carriages operable to move the first and second carriages in the U-shaped channels; The Accused Product has at least one actuator connected to and operable to move the carriages. ¶36(h) col. 4:45-46
  • Identified Points of Contention:
    • Scope Questions: The analysis may focus on whether the accused product's support structure meets the specific positional and functional requirements of a "horizontally extending truss on the outside of the door." The definitions of "generally U-shaped" and "generally horizontal" may also be disputed if the accused product's components deviate from perfectly geometric shapes.
    • Technical Questions: A key question will be whether the complaint provides sufficient evidence that the accused product's "actuator" is connected and operates in the manner required by the claim, linking it to both carriages to cause the coordinated vertical and tilting movement.

U.S. Patent No. 8,539,716 Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
a door frame comprising a pair of vertically juxtaposed members defining a vertical track; The Accused Product has a door frame with a pair of members that define a vertical track. ¶44(b) col. 1:29-32
at least one first cam surface extending generally laterally from the vertical track...wherein the at least one first cam surface has a first steep inclined segment, a second inclined segment and a third descending segment; The Accused Product has a cam surface that extends from the vertical track and allegedly possesses the three distinct claimed segments. ¶44(c) col. 1:33-38
a door sized to span the opening and pivotally coupled with at least one roller disposed within the vertical track, and at least one cam follower... The Accused Product has a door with at least one roller in the track and at least one cam follower to engage the cam surface. ¶44(d) col. 1:39-44
...an upwardly-directed motive force acts upon the door, the at least one cam follower comes into abutment with the first steep inclined segment...then into abutment with the second inclined segment...and then into abutment with the third descending segment... The Accused Product operates such that an upward force causes its cam follower to engage the three cam surface segments in sequence, moving the door to an open position. ¶44(e) col. 1:45-51
  • Identified Points of Contention:
    • Scope Questions: The dispute will almost certainly center on the term "third descending segment." The construction of "descending" will be critical. Does it require a negative slope, or could a horizontal or near-horizontal segment meet the definition, potentially under the doctrine of equivalents?
    • Technical Questions: A factual question will be whether the accused product's cam surface actually has three functionally distinct segments that correspond to the claim. The complaint’s assertion will need to be substantiated with evidence demonstrating that the accused cam profile performs the specific functions of vertical lift, then rotation, then "descending" into an open position.

V. Key Claim Terms for Construction

  • Term from the ’446 Patent: "horizontally extending truss"

    • Context and Importance: This term appears in claim 1 and defines a key structural support element. Its construction is important because infringement may depend on whether the defendant’s door reinforcement structure is properly characterized as a "truss" and meets the claim's specific positional requirements ("on the outside of the door...to be outside the door opening when the door is in the open position").
    • Intrinsic Evidence for Interpretation:
      • Evidence for a Broader Interpretation: The specification states the "truss 12 can be sized to provide the desired support for tilt-up door 10 to prevent sagging," suggesting a functional definition based on preventing sag rather than a strict structural one ('446 Patent, col. 4:7-9).
      • Evidence for a Narrower Interpretation: Figure 2 of the patent depicts the truss (12) as a conventional triangular lattice structure, which may support an argument that the term should be limited to such configurations. The specification also repeatedly refers to the structure as "truss 12," consistently using that term for the depicted embodiment ('446 Patent, col. 3:42-45; Fig. 2).

  • Term from the ’716 Patent: "a third descending segment"

    • Context and Importance: This term defines a critical and specific feature of the claimed cam surface geometry in claim 1. Whether the accused product infringes will likely depend on whether its cam surface has a feature that meets this definition, either literally or under the doctrine of equivalents. A cam that simply flattens or continues to incline would not literally meet this limitation.
    • Intrinsic Evidence for Interpretation:
      • Evidence for a Broader Interpretation: The summary of the invention describes the function of this segment as being to "bring the door into an opened, raised position," which could be argued to encompass leveling off or settling, not strictly moving downward in elevation ('716 Patent, col. 1:49-51).
      • Evidence for a Narrower Interpretation: The plain meaning of "descending" implies a downward slope. Furthermore, the specification contrasts this segment with the "steep inclined" and "inclined" segments, suggesting a different, non-upward direction of travel ('716 Patent, col. 1:36-38). Figure 10A, which illustrates an alternate embodiment, shows a cam surface (57) that appears to have a slight downward curve at its end, which could be used to argue for a literal downward slope requirement.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges that FMBC "instructs and informs its customers of the Accused Product how to infringe," which may support a claim for induced infringement (Compl. ¶29).
  • Willful Infringement: The complaint alleges willful infringement for all asserted patents. This allegation is based on alleged pre-suit knowledge of the patents and infringement via a notice letter sent on March 26, 2025, to which Defendant allegedly failed to respond (Compl. ¶¶33, 39-41).

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

  • A core issue will be one of definitional scope: can the precise geometric profiles of the "cam surfaces" described in the patents—such as the "third descending segment" of the ’716 Patent—be construed to cover the corresponding surfaces of the accused product, or will the analysis depend heavily on the doctrine of equivalents?
  • A key evidentiary question will be establishing the precise operation and structure of the accused product. The infringement case hinges on mapping each claimed mechanical and hydraulic component—from carriages and cam followers to specific hydraulic valves in the ’107 Patent—onto the defendant's system, a process that will depend on technical evidence beyond the initial complaint photographs.
  • A central legal question will concern willfulness. The outcome will depend on the sufficiency of the pre-suit notice and what actions, if any, Defendant took to assess the risk of infringement after being notified of the patents.