Firearm Reset Bar Mechanism for Rapid Semi-Auto Fire
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Solution Overview
Problem
Conventional semi-automatic firearms, such as striker-fired pistols, have a limited rate of fire due to the need for manual reset of the trigger after each shot, which can lead to slower firing rates and safety risks when the slide cycles faster than the shooter can release the trigger.
Innovation Solution
A firing mechanism incorporating a linear cam and reset bar that allows the trigger bar to be moved rearward out of engagement with the sear lower arm during the slide cycle, enabling the pistol to fire again as soon as the slide is fully closed and the pistol is in battery, with an optional selector to disable rapid fire for conventional operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the trigger is manually reset after each shot, then the firearm operates safely and reliably, but the rate of fire is limited and shooting efficiency decreases
Solution Approach 1:
The reset bar is positioned and configured in advance during the slide's rearward movement, so that when the slide cycles forward, the reset bar automatically moves the trigger bar rearward out of engagement with the sear lower arm before the trigger can be manually reset. This preliminary positioning eliminates the need for manual trigger reset while maintaining safety.
Solution Approach 2:
The firing mechanism uses the slide's own cyclic movement to automatically reset the trigger through the reset bar and cam follower interaction. The system serves itself by converting the slide's rearward motion into automatic trigger bar repositioning, eliminating the need for separate manual reset actions by the shooter.
2Productivity
If the slide cycles faster than the trigger can be released, then the rate of fire increases, but safety risks increase due to potential out-of-battery firing
Solution Approach 1:
The reset bar acts as an intermediary mechanism between the slide and the trigger bar. It mediates the interaction by using the cam follower to control the trigger bar's position, ensuring the trigger bar is moved rearward out of engagement with the sear lower arm at the appropriate moment in the slide cycle, preventing out-of-battery firing while enabling rapid fire.
Solution Approach 2:
The cam follower provides feedback from the slide's position and movement to the reset bar, which in turn positions the trigger bar accordingly. This feedback mechanism ensures the trigger bar is repositioned based on the slide's actual cyclic movement, maintaining safety controls even at high rates of fire.
3Ease of operation
If the trigger bar projection remains engaged with the sear lower arm during slide cycling, then the conventional firing mechanism operates, but the rate of fire is limited by manual trigger reset
Solution Approach 1:
The system provides dynamic adjustability by allowing the trigger bar projection to be moved rearward out of engagement with the sear lower arm during slide cycling. This dynamic repositioning enables rapid fire mode when needed, while the mechanism can be configured to maintain conventional operation when the trigger bar projection remains engaged, providing flexibility in operational modes.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This mechanism increases the semi-automatic firearm's rate of fire by allowing trigger pull as soon as the action is mechanically reset, enhancing shooting efficiency while maintaining safety by preventing out-of-battery firing.
Implementation Method 1
A cam profile gap 50 is provided to accommodate movement of the cam follower 30 when the trigger 4 is pulled to fire the pistol.
Implementation Method 2
The striker, now released, is propelled in the forward direction by a striker spring.
Implementation Method 3
A sear spring rotates the sear about the sear axis of rotation and returns the sear to the cocked position.
Data Source
AI summary
A firing mechanism for a striker-fired, magazine-fed semi-automatic pistol includes a linear cam that is attached to and moves with a slide. The linear cam moves a cam follower that pivots a reset bar. The reset bar bears upon a trigger bar projection, moving the trigger bar projection out of engagement with a lower end of a sear lower arm as the slide closes. Interference between the reset bar and the trigger bar projection prevents a second pull of the trigger from releasing the sear and moving the sear to the firing position to fire a second round until the pistol is in battery, while allowing the shooter to achieve a high rate of semi-automatic fire.