Obviousness — US Patent US11346627

Obviousness Analysis of US11346627

This analysis considers the obviousness of US patent US11346627 under 35 U.S.C. § 103, focusing on combinations of prior art references. According to KSR International Co. v. Teleflex Inc., a patent claim is obvious if "some motivation or suggestion to combine the prior art teachings" can be found in the prior art, the nature of the problem, or the knowledge of a person having ordinary skill in the art (POSITA). The Supreme Court emphasized a flexible approach to obviousness, rejecting a rigid "teaching, suggestion, or motivation" (TSM) test.

The independent claims of US11346627 (Claims 1 and 6) describe a forced reset semiautomatic trigger mechanism with a sliding locking bar. The core features include a hammer with a sear notch, a trigger member with a sear, a mechanism where the hammer forcibly contacts the trigger to reset it when the bolt carrier cycles, and a locking bar that slides to block the trigger until the bolt carrier is in a substantially in-battery position. Claim 6 further specifies that these components are within a housing.

Combination 1: US10514223B1 in view of US7398723B1

US10514223B1 (Wolf Tactical LLC): This patent, explicitly referenced in US11346627, describes a forced reset semiautomatic trigger assembly where the hammer forcibly resets the trigger, and a pivoting locking bar blocks trigger movement until the bolt returns to battery. This patent serves as a strong primary reference as it discloses nearly all elements of US11346627, specifically the "forced reset" mechanism and a locking bar that prevents firing until the bolt carrier is in-battery.
US7398723B1 (Blakley): This patent describes a "trigger forward displacement system" that utilizes the reciprocating mechanism of a firearm to reset the trigger to the ready-to-fire position. It explicitly states that 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." While not explicitly detailing a "sliding" locking bar, this patent teaches the concept of using the bolt carrier's movement to control trigger readiness. It also mentions a "spring biased paddle" as a prior art attempt to urge the trigger forward.
Motivation to Combine: A POSITA would be motivated to combine the teachings of US10514223B1 and US7398723B1. US10514223B1 already provides the forced reset and a locking bar. The problem addressed by US11346627 is improving the locking bar's operation and adjustability, particularly to compensate for tolerance stacking in AR-pattern firearms. US7398723B1, in its general teaching of using the reciprocating bolt carrier to manage trigger readiness and its reference to a "spring biased paddle," suggests mechanisms that interact with the bolt carrier. A POSITA seeking to improve upon the pivoting locking bar of US10514223B1 would look for alternative mechanisms for controlling the trigger's ability to fire based on bolt carrier position. The concept of a sliding mechanism, as opposed to a pivoting one, is a common engineering alternative. Given the existing "forced reset" functionality of US10514223B1 and the general concept of bolt-carrier-controlled trigger readiness in US7398723B1, a POSITA would find it obvious to implement the locking function with a sliding bar instead of a pivoting one, especially to enhance adjustability and address tolerance issues as mentioned in US11346627. The desire for "alternative construction" and "adjustable configurations" to compensate for "tolerance stacking" in AR-pattern firearms, as articulated in US11346627, would provide the motivation to adapt a sliding mechanism for the locking bar.

Combination 2: US10514223B1 in view of general knowledge of trigger mechanisms and mechanical equivalents

US10514223B1 (Wolf Tactical LLC): As noted, this patent provides the fundamental forced reset trigger mechanism with a pivoting locking bar.
General Knowledge of Mechanical Equivalents: A POSITA in firearm design would understand that many mechanical actions can be achieved through different kinematic arrangements. For example, a pivoting motion can often be replaced by a linear sliding motion, and vice versa, to achieve similar blocking or engaging functions. Common trigger mechanisms often involve pins for pivoting components. The use of guide rods and springs for linear movement is also fundamental in mechanical design.
Motivation to Combine: The motivation to modify the pivoting locking bar of US10514223B1 to a sliding locking bar would stem from known engineering principles. A POSITA would recognize that a sliding mechanism could offer benefits such as different spatial packaging, potentially more direct engagement, or, as explicitly stated in US11346627, improved adjustability to compensate for manufacturing tolerances. The patent itself highlights that the "present invention changes the motion of the locking bar from pivotal movement to a linear, sliding movement" and "also allows for adjustable configurations... which can help compensate for the tolerance stacking effects previously described." This indicates that the change to a sliding mechanism was a known alternative aimed at solving recognized problems in the field. Therefore, replacing a pivoting locking bar with a sliding locking bar, guided by a rod and biased by a spring, to perform the same function of blocking the trigger until the bolt carrier is in-battery, would be an obvious design choice for a POSITA seeking to improve the existing forced reset trigger described in US10514223B1.

Conclusion on Obviousness

Claims 1 and 6 of US11346627 appear to be obvious in light of the prior art, particularly US10514223B1, when combined with either US7398723B1 or general engineering knowledge. The shift from a pivoting locking bar (as in US10514223B1) to a sliding one, while addressing issues like tolerance stacking and adjustability, represents a design choice that a person of ordinary skill in the art would have been motivated to make using known mechanical equivalents and principles. The problem of imprecise actuation due to tolerance stacking in AR-pattern firearms, as described in US11346627, would further motivate a POSITA to seek such a design modification that allows for better adjustment and engagement.