Solid-state full auto sear

What is this patent about?

’416 is related to the field of firearm firing mechanisms, specifically those designed to regulate the rate and mode of automatic fire. In traditional automatic weapons, the cyclic rate is dictated by the physical mass and travel distance of the bolt, which often results in a high rate of fire that causes significant muzzle climb and reduced accuracy. Existing mechanical solutions to this problem are often bulky, complex, and difficult to retrofit into standard weapon platforms like the M16 or M4.

The underlying idea behind ’416 is to replace or augment the traditional mechanical auto-sear with a solid-state piezoelectric element that acts as a high-speed electronic gate for the hammer. By using a material that physically changes shape in response to an electrical charge, the system can catch and release the hammer at precise intervals. This allows the weapon’s firing rate to be governed by a digital controller rather than the raw mechanical speed of the action, enabling a perfectly optimized cadence regardless of the weapon's weight or bolt velocity.

The claims of ’416 focus on a firing mechanism where a one-piece piezoelectric sear directly engages the hammer to control the firing cycle. The independent claims describe a system where this solid-state component transitions between two electrical states—typically a bowed shape and a flat shape—to either hold the hammer in a cocked position or release it to strike the firing pin. This electronic control allows for specific firing behaviors, such as fixed-count bursts or reduced cyclic rates, to be programmed into the weapon's logic.

In practice, the system utilizes a sensor to detect the position of the bolt or hammer, signaling the controller that a cycle has occurred. The controller then energizes the piezoelectric sear to catch the hammer, holding it for a calculated number of milliseconds before cutting the power to release it for the next shot. To ensure the hammer can always move fully rearward even if the sear is already in the 'catch' position, the invention optionally employs a retractable hammer bent that allows the hammer to snap past the sear during recoil before being captured on the return stroke.

This approach differs from prior art by eliminating the complex linkages and friction-heavy mechanical delays used in traditional rate-reduction systems. Because the timing is handled by a microprocessor, the weapon can offer multiple distinct modes—such as a ultra-crisp electronic sniper trigger or various burst lengths—without changing physical parts. Crucially, the design is compact enough to be retrofitted into existing lower receivers, providing a digital upgrade to proven mechanical platforms while maintaining a fail-safe manual firing capability.