Trigger assembly with trigger block

What is this patent about?

’734 is related to the field of firearm safety mechanisms, specifically focusing on trigger assemblies designed to prevent accidental discharge. The background context involves the inherent risk of a firearm firing when dropped or subjected to sudden impacts, where inertial forces can cause the trigger to move even if a manual safety is engaged. The invention aims to provide a robust mechanical lock that remains secure under high-G loads while allowing for a natural, intentional firing sequence.

The underlying idea behind ’734 is the use of a secondary, balanced locking member that physically obstructs the main trigger until a deliberate pull is initiated. By integrating a pivotable trigger block directly onto the trigger blade, the system ensures that the primary trigger is mechanically immobilized by a spring-loaded plunger. The key insight is to decouple the sear release from the initial finger pressure, requiring a two-stage movement where the first stage clears a physical stop and the second stage releases the firing mechanism.

The claims of ’734 focus on a multi-component safety linkage comprising a sear, a trigger, a movable body or plunger, and a trigger block. The independent claims specifically protect the arrangement where the plunger acts as a bridge between the trigger block and a stop surface; the trigger block must be moved to shift the plunger along a specific line of action, which in turn disengages a stop surface from a contact point on the trigger. This mechanical chain ensures the trigger cannot pivot to release the sear unless the plunger is first displaced by the trigger block.

In practice, the invention utilizes a counter-balanced geometry for both the trigger and the trigger block to neutralize inertial forces. By aligning the center of gravity of these components with their respective pivot pins, the assembly becomes essentially immune to shocks from any direction, as the impact force does not generate the torque necessary to rotate the parts. The plunger is housed within a central cavity and is biased by a spring to maintain the locked state, ensuring the system defaults to a safe condition.

This approach differs from prior solutions by replacing simple friction-based safeties or manual levers with a dynamic interlocking plunger mechanism. Unlike traditional designs where a safety might fail if the firearm hits the ground at a specific angle, the ’734 design uses the plunger as a positive mechanical interference that is only cleared when the shooter’s finger depresses the trigger block. The inclusion of a set screw with a notch allows for precise adjustment of the contact point, providing a crisp release that does not sacrifice drop-safety for trigger feel.