Obviousness

Obviousness Analysis of U.S. Patent 7,398,723 Under 35 U.S.C. § 103

This section evaluates the obviousness of U.S. Patent 7,398,723 ("the '723 patent") under 35 U.S.C. § 103, considering combinations of the prior art references analyzed previously. The '723 patent contains a single independent claim, Claim 1, which describes a method for accelerating the firing cycle of a semi-automatic firearm.

Claim 1: A method of accelerating the firing cycle of a semi-automatic firearm comprising the steps of: depressing a firearm trigger with a finger to discharge the firearm; activating a reciprocating mechanism within the firearm that causes a cam, in a single rotational motion of the cam, to simultaneously push the trigger forward into a ready to fire position and hold the trigger forward in the ready to fire position until the reciprocating mechanism has reached an approximately closed, ready to fire position.

Combination: U.S. Patent No. 4,023,465 to Inskip in view of general mechanical engineering principles

Prior Art Reference: U.S. Patent 4,023,465 to Inskip discloses a firearm mechanism where the cycling of the bolt carrier (a reciprocating mechanism) moves the trigger to a forward, ready-to-fire position and then locks it there until the bolt carrier returns to battery. Inskip's stated purpose is to regulate the rate of fire, which inherently involves accelerating the cyclic firing rate by enabling rapid trigger resets.

Elements of Claim 1 present in Inskip:

• "depressing a firearm trigger with a finger to discharge the firearm": This is a standard action in all firearms and is implicitly disclosed by Inskip.
• "activating a reciprocating mechanism within the firearm": Inskip explicitly describes the use of the cycling bolt carrier as the reciprocating mechanism.
• "to push the trigger forward into a ready to fire position": Inskip discloses that the cycling bolt carrier moves the trigger to the "forward ready-to-fire position."
• "and hold the trigger forward in the ready to fire position until the reciprocating mechanism has reached an approximately closed, ready to fire position": Inskip describes that the trigger is "locked in that position until the bolt carrier returns to battery," which is an "approximately closed, ready to fire position."

Distinguishing Feature of Claim 1 from Inskip:
The primary distinction, as identified by the '723 patent itself, lies in the specific mechanism for interacting with the trigger: "that causes a cam, in a single rotational motion of the cam, to simultaneously push the trigger forward" and do so without causing binding. The '723 patent criticizes Inskip's mechanism for using a lever that allows operator's trigger finger pressure to be transmitted vertically to the bolt carrier, causing friction and potential binding, especially at lower kinetic energy states of the bolt carrier. The '723 patent's cam is designed to avoid this problem, ensuring the operator's finger pressure is borne by the accelerating mechanism and not transmitted to the reciprocating member as an upward displacing force.

Motivation to Combine:
A person having ordinary skill in the art (POSITA) in firearm design, seeking to implement or improve upon the accelerated firing rate mechanism described by Inskip, would be aware of the mechanical challenges associated with direct or lever-based engagement of a reciprocating part, such as friction and potential binding. The '723 patent explicitly identifies this "highly undesirable stoppage" as a problem with Inskip's design.

Cams are widely known mechanical elements used to convert reciprocating motion into controlled rotational motion, and to transmit forces while managing contact dynamics, often specifically to reduce friction, avoid binding, and achieve smoother, more reliable operation than simple levers in mechanical systems where precise timing and force transmission are critical. Therefore, a POSITA, recognizing the binding issue described in Inskip's system, would have a clear motivation to substitute a cam for Inskip's lever to achieve a smoother, more reliable, and non-binding interaction with the trigger. The design of a cam to engage the trigger, performing a "single rotational motion" to "simultaneously push the trigger forward into a ready to fire position and hold the trigger forward" while preventing unwanted force transmission to the bolt, would be a straightforward application of well-known mechanical engineering principles to improve the functionality and reliability of Inskip's existing rapid-fire trigger reset system.

Conclusion:
Given Inskip's disclosure of all the functional steps of Claim 1, combined with the readily apparent motivation for a POSITA to substitute a cam for a lever to address known mechanical issues like friction and binding, Claim 1 of U.S. Patent 7,398,723 would likely have been obvious to a POSITA at the time of the invention. The specific mechanical implementation of a cam to achieve a non-binding reset action is an engineering choice well within the purview of a POSITA attempting to optimize Inskip's system.

Other Cited Prior Art References

• U.S. Patent No. 6,101,918 to Akins: Akins describes a "bump-stock" type mechanism where the entire firearm recoils away from a stationary trigger finger to reset the trigger. This method does not involve an internal reciprocating mechanism causing a cam to push the trigger forward. Thus, Akins does not provide the missing elements or a direct motivation to combine with Inskip in a way that addresses the cam aspect of Claim 1.
• U.S. Patent No. 4,787,288 to Miller: Miller discloses an external, crank-actuated device to repeatedly pull and release the trigger. It does not utilize the firearm's internal reciprocating mechanism or a cam for trigger reset. Therefore, it does not contribute to an obviousness argument for Claim 1 when combined with Inskip.
• U.S. Patent No. 4,697,495 to Beretta: Beretta concerns converting closed-bolt rifles to open-bolt operation, which is distinct from accelerating the firing rate by actively resetting the trigger with a cam. This reference is not relevant to an obviousness combination for Claim 1.

Therefore, the most compelling obviousness argument for Claim 1 rests on the combination of Inskip and general mechanical engineering knowledge concerning the use of cams to improve force transmission and prevent binding in mechanical systems.