Obviousness

Obviousness Analysis of US Patent 10,514,223 under 35 U.S.C. § 103

A technical analysis under 35 U.S.C. § 103 suggests that claims 1 and 4 of U.S. Patent 10,514,223 would have been obvious to a person having ordinary skill in the art (POSITA) at the time of the invention (priority date September 29, 2017), given the teachings of the prior art. The claimed invention, which focuses on a semi-automatic firearm trigger mechanism featuring a hammer-actuated trigger reset and a bolt carrier-actuated locking bar, combined within a drop-in module, appears to be a combination of known elements with predictable results.

Independent Claims Overview

The core of the invention is captured in two independent claims:

• Claim 1 describes a trigger mechanism with a hammer having a sear notch, a trigger member with a sear (where a surface of the trigger is contacted by the hammer when displaced by the cycling bolt carrier to force the trigger to the set position), and a pivotally mounted, spring-biased locking bar. This locking bar mechanically blocks the trigger from moving to the released position and is movable by contact with the bolt carrier reaching a substantially in-battery position, allowing the trigger to be pulled.
• Claim 4 describes essentially the same mechanism as Claim 1, but specifically within a self-contained "housing" that forms a drop-in module for installation into a firearm's fire control mechanism pocket.

Prior Art Combinations and Motivation to Combine

Several prior art references, particularly those discussing accelerated firing rates, trigger reset mechanisms, and modular trigger assemblies, provide the foundational elements that, when combined, render the claims of US10514223 obvious.

Combination for Obviousness of Claim 1

A primary combination for rendering Claim 1 obvious involves US9021732B2 (Johnson), US7398723B1 (Blakley), and the collective teachings of the Thomas Allen Graves patents (e.g., US9939221B2).

1. Hammer and Trigger Reset Functionality:

   • Johnson (US9021732B2) describes a "trigger reset assist apparatus and method" that uses a torsion spring to translate force from a bolt carrier group to a trigger to assist in resetting the trigger. Johnson explicitly notes that the trigger assist spring increases the rate at which the trigger engages the hammer. The patent also details the hammer engaging the disconnector and the hammer interlock engaging the trigger sear to lock the hammer in a cocked position.

   • The Graves patents (e.g., US9939221B2, US20160102933A1), as acknowledged by US10514223, disclose devices that "forcefully reset the trigger with rigid mechanical contact between the trigger member and the bolt as the action cycles." [cite: 4, 5, 9, "BACKGROUND" section of US10514223] This clearly teaches the concept of a forced trigger reset by a reciprocating action. US9939221B2 states that the trigger is "reset by interference contact with the gun bolt."

   • Motivation to Combine/Modify: A POSITA, seeking to improve the reliability or simplify the forced reset mechanism described by Graves (which uses direct bolt-to-trigger contact), and understanding the interactions between the hammer, trigger, and bolt carrier as taught by Johnson, would be motivated to have the hammer directly contact a surface on the trigger to force its reset. The hammer is already being displaced rearward by the bolt carrier during the cycling action. Leveraging this existing mechanical interaction for trigger reset, rather than a separate spring or direct bolt-to-trigger contact, would be an obvious engineering optimization, particularly to allow for use with an "otherwise standard M16-pattern bolt carrier assembly," a stated benefit of US10514223.

2. Locking Bar Functionality to Prevent Premature Firing:

   • Blakley (US7398723B1) teaches a system where the trigger is "positively held in the forward, ready-to-fire position until such time as the reciprocating member has reversed direction and has reached the nearly-fully-forward position where it is safe to allow discharge of the firearm." This mechanism effectively prevents premature firing until the bolt is in battery.

   • The Graves patents (e.g., US9939221B2) also teach that the trigger "may be locked and incapable of being pulled again until the last few percent of the forward bolt stroke" and that "mechanical contact between a trigger and a gun bolt may prevent depression of a trigger during any part of the operating cycle except when in battery or within 15% of forward gun bolt stroke." This describes the functional equivalent of a locking mechanism.

   • Armament ALB (Adjustable Locking Bar): Although published after the priority date of US10514223, this product (for Forced Reset Triggers like the FRT-15) highlights the known problem of "hammer follow from early trigger release" and the utility of a "locking bar" to adjust "trigger release timing" by interacting with the carrier. This corroborates that a dedicated locking mechanism for forced reset triggers was a known desirable feature.

   • Motivation to Combine/Modify: A POSITA would recognize the critical need for a safety mechanism to prevent premature firing ("hammer follow" or "out of battery discharge") in any rapid-fire or forced-reset trigger system. Given Blakley's explicit teaching of holding the trigger until the bolt is in battery, implementing this function with a distinct, pivotally mounted, and spring-biased "locking bar" that physically interacts with the bolt carrier to block trigger movement would be an obvious design choice. This would provide a robust and adjustable safety interlock, which is a common engineering practice for critical firearm functions.

Combination for Obviousness of Claim 4

For Claim 4, which specifies the mechanism within a "drop-in" housing:

• Johnson (US9021732B2) explicitly discloses a "modular drop-in assembly that also comprises other trigger group components." Johnson further details that "the drop-in assembly comprises all the components of the trigger group... including the trigger, hammer and disconnector, as well as the disclosed trigger reset assist spring" and describes their coupling within an assembly housing.

• The background of US10514223 itself notes that the "present invention is particularly adaptable for construction as a “drop-in” replacement trigger module." [cite: "SUMMARY OF INVENTION" section] This indicates that drop-in trigger modules were a known and desired form factor in the art.

• Motivation to Combine: The advantages of drop-in trigger modules (e.g., ease of installation, pre-assembled reliability, modularity for various firearm platforms) were well-known to a POSITA. Therefore, it would be an obvious design choice to integrate any improved trigger mechanism, including one incorporating the hammer-reset and bolt carrier-actuated locking bar as in Claim 1, into a self-contained, drop-in housing. This would simply be applying a known modular design principle to a functionally improved trigger system.

Conclusion

Considering the prior art, a POSITA would have been motivated to combine the concept of a bolt-carrier-assisted trigger reset (Johnson, Graves) with a mechanism for preventing premature firing until the bolt is in battery (Blakley, Graves), and to implement such a system in a convenient drop-in module (Johnson). The specific interaction where the hammer forces the trigger to reset, and a separate locking bar controlled by the bolt carrier prevents firing until in-battery, represents an obvious variation or improvement of existing principles in firearm trigger design, driven by known desires for increased rate of fire and enhanced safety. Therefore, claims 1 and 4 of US10514223 would likely be considered obvious under 35 U.S.C. § 103.