Trigger-controlled select fire for M-16 rifle

What is this patent about?

’928 is related to the field of firearm trigger mechanisms, specifically those designed for select-fire rifles like the M-16 or AR-15. In conventional military rifles, switching between semi-automatic and fully automatic fire requires the operator to manually manipulate a safety selector switch located on the receiver. This manual transition can be inefficient in high-stress combat environments where a shooter may need to rapidly increase their volume of fire without breaking their grip or focus on the target.

The underlying idea behind ’928 is to enable mode selection through variable trigger pressure rather than a manual switch. By integrating a secondary pivoting component—a rocker—directly onto the trigger body, the system uses the physical geometry of the trigger pull to change the mechanical state of the fire control group. The key insight is using the floor of the trigger enclosure as a mechanical stop that, when struck by the rocker during a deep trigger pull, forces the rocker to pivot and physically override the disconnector.

The claims of ’928 focus on a trigger assembly featuring a full auto rocker mounted to the trigger at a dedicated third pivot axis. The rocker is designed with a forward portion that extends toward the enclosure floor and a rearward portion that overlies the disconnector. When the trigger is pulled beyond the standard semi-automatic break point, the rocker’s forward end hits the enclosure bottom, causing the entire rocker to rotate and push the disconnector downward, which prevents it from capturing the hammer and allows for continuous cycling.

In practice, the system functions as a two-stage interface while the safety selector remains in the semi-automatic position. A standard pull releases the hammer for a single shot, but continuing to pull the trigger with added pressure engages the cam-shaped ends of the rocker against the receiver floor. This forced rotation ensures the disconnector is held out of the way, allowing the rifle’s auto-sear to take over the timing of the hammer release for as long as the trigger is held in this over-travel position.

This approach differs from prior art by eliminating the need to toggle a selector lever to achieve high-volume fire. While traditional systems rely on the selector to physically block or move the disconnector, the ’928 invention utilizes a pressure-activated transition that is entirely internal to the trigger pull stroke. By modifying the safety selector with a relief slot to prevent interference, the inventor allows the weapon to cycle automatically even when the external controls suggest it is in semi-automatic mode.