Roller Sear Trigger Mechanism for Low-Force Firearm Reset
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Solution Overview
Problem
Existing hammer-type trigger mechanisms in firearms require significant force to operate due to the resistance of the trigger return spring, leading to inaccurate shooting.
Innovation Solution
A trigger mechanism with a roller sear and guide rod system that reduces the force required by disabling the impact of the trigger return spring through a safety lock and cam engagement, allowing the roller sear to smoothly return to a locked position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If a trigger return spring is used to automatically return the trigger to the firing position, then the trigger mechanism can operate automatically after each shot, but the spring creates resistance that increases the force required to operate the trigger, reducing shooting accuracy
Solution Approach 1:
The trigger mechanism is divided into separate functional components: the trigger body, the return mechanism with plunger and spring, and the cam system. This segmentation allows the return function to be independent from the trigger operation, enabling automatic return without adding resistance to trigger pull.
Solution Approach 2:
The cam surface is pre-configured to guide the protrusion during trigger movement. The cam engagement prepares the system in advance by controlling the interaction between moving parts, ensuring smooth operation and reducing the force needed during actual trigger activation.
2Speed
If the trigger return spring is engaged during trigger closure, then the trigger can be rapidly reset, but the spring impact creates instability and reduces shooting accuracy
Solution Approach 1:
The cam surface is designed to cushion the interaction between the protrusion and the return mechanism before the spring fully engages. This gradual engagement reduces shock and impact forces, allowing rapid reset without compromising stability or accuracy.
Solution Approach 2:
The cam acts as an intermediary element between the trigger protrusion and the return spring. It mediates the interaction by controlling the timing and manner of spring engagement, smoothing out the reset action and eliminating harmful impacts.
3Reliability
If the roller sear is designed to engage with the hammer notch, then reliable firing engagement is achieved, but the engagement creates friction and resistance during trigger operation
Solution Approach 1:
A roller element is used instead of a traditional flat sear surface. The cylindrical roller contacts the hammer notch surface, converting sliding friction into rolling friction. This curvature reduces the force required during engagement and disengagement while maintaining reliable firing lock.
Solution Approach 2:
The traditional sliding sear mechanism is replaced with a rolling roller system. This substitution changes the fundamental mechanical interaction from high-friction sliding contact to low-friction rolling contact, reducing operational force requirements.
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 design significantly reduces the force needed on the trigger, enhancing shooting accuracy and ensuring safety by disabling the spring impact, with no misfires or delays during 1500 test shots.
Implementation Method 1
a roller mounted on the sear and configured to roll on an engagement surface of the notch made in the hammer
Implementation Method 2
The hammer and the trigger have cams engaging with each other and allowing the protrusion of the trigger to return to the firing position
Implementation Method 3
By default, the hammer is acted upon by a spring
Data Source
AI summary
The invention is aimed at improving the accuracy of shooting by reducing the force on a trigger of a firearm during firing. The technical result is achieved by the fact that the design of the trigger mechanism includes a housing in which a hammer and a hammer spring are installed, a tubular axle on which the trigger having a groove allowing longitudinal movement along the axle is installed, thereby disengaging a return mechanism installed in its housing, a roller sear, and a single-fire sear. To engage the return mechanism, the trigger and the hammer are equipped with cams, and when a breechblock carrier is recoiled, the hammer is lowered and its cam affects the trigger cam, forcing the trigger to move backwards (if it has been moved to a forward position before). The return mechanism is also engaged when a safety lock is activated.