ABC IP LLC v. HK Parts

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: ABC IP, LLC (Delaware) and Rare Breed Triggers, Inc. (Texas)
  • Defendant: HK Parts Inc. (Utah)
  • Plaintiff’s Counsel: Fish & Richardson P.C.
• Case Identification: 4:26-cv-01045, E.D. Tex., 10/07/2026
• Venue Allegations: Venue is alleged to be proper in the Eastern District of Texas because Defendant resides in the district, has committed acts of infringement there, and maintains a regular and established place of business in the district.
• Core Dispute: Plaintiffs allege that Defendant’s aftermarket firearm trigger mechanisms infringe five U.S. patents related to "forced reset" technology, which is designed to increase the rate of fire of semi-automatic firearms.
• Technical Context: The technology at issue involves mechanical trigger assemblies that use the reciprocating motion of a firearm's bolt carrier to mechanically reset the trigger, enabling a faster firing sequence than is possible with standard semi-automatic triggers.
• Key Procedural History: This filing is a Second Amended Complaint. Plaintiff ABC IP, LLC is the owner of the Asserted Patents, and Plaintiff Rare Breed Triggers, Inc. is the exclusive licensee.

Case Timeline

Date	Event
2021-11-05	Priority Date for ’784 Patent
2022-09-08	Priority Date for ’247 Patent
2022-09-08	Priority Date for ’159 Patent
2023-12-04	Priority Date for ’538 Patent
2024-07-09	’784 Patent Issued
2024-07-16	’247 Patent Issued
2025-01-21	Priority Date for ’403 Patent
2026-01-20	’538 Patent Issued
2026-03-17	’159 Patent Issued
2026-05-26	’403 Patent Issued
2026-10-07	Complaint Filing Date

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

U.S. Patent No. 12,038,247 - "Firearm Trigger Mechanism"

• Issued: July 16, 2024

The Invention Explained

• Problem Addressed: In a standard semi-automatic firearm, a component called a disconnector holds the hammer after a shot is fired until the user manually releases the trigger Compl. ¶¶18-19 This requirement to manually reset the trigger limits the potential rate of fire (Compl. ¶19; ’247 Patent, col. 1:29-34).
• The Patented Solution: The invention is a trigger mechanism that replaces the standard disconnector function with a selectable "forced reset" system Compl. ¶20 In this mode, a pivoting cam, actuated by the rearward movement of the firearm's bolt carrier, mechanically forces the trigger member back to its reset position (’247 Patent, abstract). This allows the user to fire a subsequent round immediately upon the bolt returning to battery, without first needing to release pressure on the trigger (Compl. ¶21; ’247 Patent, col. 2:56-67). The mechanism is selectable between this "forced reset" mode and a standard semi-automatic mode (’247 Patent, abstract).
• Technical Importance: This approach provides a method for substantially accelerating the rate of semi-automatic fire through a mechanical, selectable trigger assembly Compl. ¶21

Key Claims at a Glance

• The complaint asserts one or more claims, including independent claim 15 Compl. ¶41
• Essential elements of independent claim 15 include:
  • A firearm trigger mechanism comprising a hammer, a trigger member, a disconnector, a cam, and a safety selector.
  • The mechanism is operable in a "standard semi-automatic mode" where, after firing, the disconnector hook catches the hammer hook, requiring the user to manually release the trigger to reset the mechanism for the next shot.
  • The mechanism is also operable in a "forced reset semi-automatic mode" where the cam, moved by the bolt carrier, forces the trigger member to the set position, and the safety selector prevents the disconnector from catching the hammer, allowing the user to fire again without manually releasing the trigger.
• The complaint does not explicitly reserve the right to assert dependent claims, but generally alleges infringement of "one or more claims" Compl. ¶41

U.S. Patent No. 12,031,784 - "Adapted Forced Reset Trigger"

• Issued: July 9, 2024

The Invention Explained

• Problem Addressed: Previous forced reset trigger designs were often specific to one firearm platform (like the AR-15). Adapting them to other platforms (like the AR-10) with different internal dimensions was problematic; simply extending a locking bar to engage the AR-10's bolt carrier would cause it to interfere with another part of the bolt carrier as it cycled rearward (’784 Patent, col. 1:21-44).
• The Patented Solution: The patent describes an extended trigger locking member that incorporates a "deflectable" or hinged upper portion (’784 Patent, abstract). This extension is long enough to be actuated by the forward movement of a bolt carrier (e.g., in an AR-10), but is also designed to fold or deflect out of the way when contacted by a lower surface of the bolt carrier as it moves to the rear (’784 Patent, col. 4:26-37). This one-way action allows the locking member to function without interfering with the bolt carrier's full cycle of operation (’784 Patent, FIG. 7).
• Technical Importance: The invention enables the adaptation of forced reset trigger technology to a wider variety of semi-automatic firearm platforms with different bolt carrier geometries (’784 Patent, col. 1:45-49).

Key Claims at a Glance

• The complaint asserts one or more claims, including independent claim 1 Compl. ¶61
• Essential elements of independent claim 1 include:
  • An extended trigger member locking device for a forced reset trigger mechanism.
  • A locking member movable between a first (locking) and second (unlocked) position.
  • The locking member has an upward extension portion to make contact with a bolt carrier.
  • The locking member is composed of a movably supported "body portion" and an "upwardly extending deflectable portion that is separately movable relative to the body portion" between an extended and deflected position.
• The complaint does not explicitly reserve the right to assert dependent claims but alleges infringement of "one or more claims" Compl. ¶61

Multi-Patent Summary

• U.S. Patent No. 12,529,538 - "Safety Mechanism for Firearm"

  • Issued: January 20, 2026.
  • Technology Synopsis: The patent describes a safety mechanism for a firearm that uses a multi-mode cam selector (’538 Patent, abstract). The selector allows operation in a standard semi-automatic mode, a safe mode, and an "active reset" mode where a cam portion acts on the trigger tail to force a reset (Compl. ¶23; ’538 Patent, abstract).
  • Asserted Claims: Claim 1 is asserted Compl. ¶83
  • Accused Features: The 3-position "Super Safety" product is accused of embodying the claimed three-mode cam selector mechanism Compl. ¶28 Compl. ¶81

• U.S. Patent No. 12,578,159 - "Firearm Trigger Mechanism"

  • Issued: March 17, 2026.
  • Technology Synopsis: This patent, similar to the ’247 Patent, describes a selectable firearm trigger mechanism operable in a standard semi-automatic mode and a "forced reset" semi-automatic mode (’159 Patent, abstract). The invention uses a cam actuated by the bolt to mechanically reset the trigger, thereby addressing the firing rate limitations of standard triggers Compl. ¶21
  • Asserted Claims: Claim 1 is asserted Compl. ¶101
  • Accused Features: The "Super Safety," "Atrius Selector," and "ARC-Fire" products are accused of infringing by embodying the claimed dual-mode functionality Compl. ¶99

• U.S. Patent No. 12,636,403 - "Firearm Trigger Mechanism"

  • Issued: May 26, 2026.
  • Technology Synopsis: The patent describes a trigger mechanism with a safety selector for moving between a standard semi-automatic position and a "forced reset" semi-automatic position (’403 Patent, abstract). In the standard mode, the user must reduce pressure on the trigger to permit reset, while in the forced reset mode, this is not required Compl. ¶¶129-130
  • Asserted Claims: Claim 38 is asserted Compl. ¶121
  • Accused Features: The complaint alleges the "Super Safety," "Atrius Selector," "ARC-Fire," and "Disruptor" products all embody the claimed selectable forced reset trigger mechanism Compl. ¶119 Compl. ¶¶121-124

III. The Accused Instrumentality

Product Identification

• The complaint identifies several accused products: the "(3-Position) 'Super Safety'" Compl. ¶28, the "(3-Position) 'Atrius Forced Reset Selector'" Compl. ¶32, the "(3-Position) 'ARC-Fire'" Compl. ¶36, and the "Disruptor" Compl. ¶124

Functionality and Market Context

• The accused products are alleged to be aftermarket trigger mechanisms for AR-15-style firearms and similar platforms Compl. ¶46 They are sold via the Defendant's website as standalone components, in kits with other parts, or pre-installed in firearm lower receivers Compl. ¶¶29, 33, 37 Functionally, they are alleged to be 3-position selectors that allow the user to switch between a "safe" mode, a "standard semiautomatic with disconnector" mode, and a "'forced reset' semiautomatic with cam modes" Compl. ¶¶31, 35, 39 The complaint includes a screenshot from Defendant's website showing the "HK MP5 Trigger Group - Super Safety" offered for sale Compl. ¶30

IV. Analysis of Infringement Allegations

U.S. Patent No. 12,038,247 Infringement Allegations

Claim Element (from Independent Claim 15)	Alleged Infringing Functionality	Complaint Citation	Patent Citation
A firearm trigger mechanism comprising: a hammer having a sear catch and a hook for engaging a disconnector... a trigger member having a sear... a disconnector having a hook... and a cam having a cam lobe...	The "Super Safety" is alleged to be part of a trigger mechanism that includes a hammer (red), a trigger member (brown), a disconnector (orange), and a cam (yellow "Super Safety"), as shown in plaintiff-generated renderings.	¶43	col. 9:1-16
said cam being movable between a first position and a second position, in said second position said cam lobe forces said trigger member towards said set position,	The Super Safety cam is alleged to be movable between two positions. In the second ("forced reset") position, the cam lobe mechanically moves the trigger member (brown) toward the set position. A diagram shows the cam and lobe in these two positions.	¶43	col. 9:17-21
whereupon in a standard semi-automatic mode, said cam is in said first position, rearward movement of the bolt carrier causes rearward pivoting of said hammer such that said disconnector hook catches said hammer hook...	In the standard mode, the cam is in the first position. The complaint alleges that rearward bolt carrier movement causes the hammer to pivot and the disconnector hook (orange) to catch the hammer hook.	¶43	col. 9:55-61
...at which time a user must manually release said trigger member to free said hammer from said disconnector... so that the user can pull said trigger member to fire the firearm,	The complaint alleges that the user must manually release the trigger member (brown) to free the hammer (red) from the disconnector (orange), allowing the mechanism to reset for the next shot. An illustration depicts this state as "Reduced Pressure on Trigger Member Allows Reset."	¶43	col. 9:61-65
whereupon in a forced reset semi-automatic mode, said cam is in said second position, rearward movement of the bolt carrier causes rearward pivoting of said hammer such that said disconnector hook is prevented from...	In the "forced reset" mode, the cam is in the second position. The complaint alleges that rearward bolt carrier movement causes the hammer to pivot, but the disconnector hook is prevented from catching the hammer hook.	¶43	col. 10:1-8
...at which time the user can pull said trigger member to fire the firearm.	The complaint alleges that in this mode, the user can pull the trigger member to fire the firearm without first having to release pressure on it.	¶43	col. 10:12-14

• Identified Points of Contention:
  • Functional Questions: A primary question will be factual: does the accused "Super Safety" mechanism perform every step of both the "standard" and "forced reset" modes exactly as required by the claim? The complaint's allegations rely on computer-generated renderings Compl. ¶43 The actual operation of the physical product, especially whether the disconnector reliably engages and disengages in the "standard mode" as claimed, will be a key evidentiary battleground.
  • Scope Questions: The claim requires the cam to "force" the trigger member toward the set position. The interpretation of "forces" may be disputed. Does this require direct, unmediated mechanical action, or could it encompass a broader range of influence?

U.S. Patent No. 12,031,784 Infringement Allegations

Claim Element (from Independent Claim 1)	Alleged Infringing Functionality	Complaint Citation	Patent Citation
In a forced rest trigger mechanism, an extended trigger member locking device, comprising: a locking member that is movable between a first position... and a second position...	The accused "Atrius Selector" is alleged to be an extended trigger member locking device. It operates as a locking member movable between a "Locked First Position" and an "Unlocked Second Position."	¶64	col. 5:16-21
...including a generally upward extension portion configured to make actuating contact with a surface of the bolt carrier,	The Atrius Selector is alleged to have an upward extending portion (a yellow lever arm) configured to make contact with a surface of the bolt carrier.	¶64	col. 5:24-26
...the locking member having a body portion that is movably supported and an upwardly extending deflectable portion that is separately movable relative to the body portion between an extended position and a deflected position.	The Atrius Selector is alleged to have a body portion (purple) and an upwardly extending "deflectable portion" (lever arm). The complaint alleges the lever arm is "separately movable" relative to the body, showing it in an extended (red) and deflected (yellow) position independent of the body. A diagram in the complaint illustrates the separate travel of the lever arm Compl. ¶64	¶64	col. 6:3-8

• Identified Points of Contention:
  • Scope Questions: The infringement analysis for the ’784 patent will likely center on the construction of "deflectable portion that is separately movable." The complaint shows the accused Atrius Selector uses a hinged lever arm Compl. ¶64 A dispute may arise over whether a pivoting, rigid hinge mechanism falls within the scope of a "deflectable portion," which could be argued to imply bending of a single, resilient piece of material.
  • Technical Questions: What evidence does the complaint provide that the accused hinged component is "deflectable" as opposed to merely "pivotable"? The patent itself uses terms like "deflects or folds" and illustrates a hinged embodiment, which may support the plaintiff's position ('784 Patent, col. 2:49-50; '784 Patent, FIGS. 8-10).

V. Key Claim Terms for Construction

• The Term: "upwardly extending deflectable portion that is separately movable" (from claim 1 of the ’784 Patent)

• Context and Importance: This term is the core inventive concept of the ’784 patent, purporting to solve the problem of adapting forced-reset triggers to different firearm platforms. The case for infringement of the ’784 patent will turn on whether the accused products' hinged lever arms meet this definition. Practitioners may focus on this term because the distinction between "deflecting" and "pivoting" is a potential area for a non-infringement argument.

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: The specification states the invention provides a "deflectable extension... that... deflects or folds" (’784 Patent, col. 2:48-50). It also explicitly describes an alternative embodiment with a "hinging movement" and a "hinged extension" (’784 Patent, col. 4:45-47), suggesting the patentee considered hinging to be within the scope of the invention.
  • Evidence for a Narrower Interpretation: A party could argue that the plain meaning of "deflectable" implies bending, not pivoting. The specification, in one embodiment, describes a resilient material "configured to deflectably bend" (’784 Patent, col. 3:49-50). This language may be used to argue that "deflectable" requires material flexure, which a rigid, hinged component might not possess.

• The Term: "forces said trigger member towards said set position" (from claim 15 of the ’247 Patent)

• Context and Importance: This phrase defines the central action of the "forced reset" mode. The scope of "forces" is critical to determining whether the accused products infringe, as it dictates the required interaction between the cam and the trigger.

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: The patent abstract and summary describe the general concept of the cam lobe forcing the trigger member toward the set position without specifying the exact mechanism, which may support a broader functional definition (’247 Patent, abstract; ’247 Patent, col. 2:56-62).
  • Evidence for a Narrower Interpretation: The detailed description and figures show a specific physical interaction where the "cam lobe 78 acts upon the cam follower 58 to pivot the trigger member 38" (’247 Patent, col. 9:49-51; ’247 Patent, FIG. 9C). An argument could be made that "forces" should be limited to this direct, physical pushing action depicted in the preferred embodiment.

VI. Other Allegations

• Indirect Infringement: The complaint alleges both induced and contributory infringement for all asserted patents. Inducement allegations are based on Defendant's alleged active steps, including providing installation instructions, promotional materials, compatibility information, and instructional videos on its website that allegedly encourage and instruct customers on how to use the accused products in an infringing manner (Compl. ¶¶46-51; Compl. ¶¶66-71). Contributory infringement is alleged on the basis that the accused components are not suitable for substantial noninfringing use and are specially designed to be used in a manner that infringes the patents Compl. ¶52 Compl. ¶72
• Willful Infringement: The complaint alleges that Defendant has engaged in "egregious infringement behavior" with knowledge of the Asserted Patents Compl. ¶53 Compl. ¶73 The basis for willfulness includes allegations that Defendant knew or should have known its actions constituted infringement, particularly after being served with the complaint, and that it could not have had a reasonable belief that its actions were non-infringing or that the patents were invalid Compl. ¶53 Compl. ¶73 Compl. ¶91

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

1. A Definitional Scope Question: A core issue will be one of claim construction, particularly for the '784 patent: can the term "deflectable portion," which may imply material bending, be construed to cover the hinged, pivoting lever arm of the accused "Atrius Selector"? The outcome of this construction could be dispositive for the infringement analysis of that patent.

2. A Factual and Functional Question: A key evidentiary question for patents like the '247 patent will be one of functional performance: do the accused products, when installed, perform every step of the complex dual-mode operation recited in the claims? The court will need to determine if the physical operation of the accused triggers, particularly in the "standard semi-automatic mode," matches the specific sequence of disconnector engagement and manual release required by the claim language.

3. An Evidentiary Question of Intent: The case for indirect and willful infringement will likely depend on the evidence of Defendant's knowledge and intent. A central question will be whether Defendant’s website content, installation videos, and product marketing materials constitute active steps to encourage infringement with the specific intent required by law, especially in the period after Defendant was made aware of the patents.