US Patent 11015893 Lever-coupled device for selectively preventing a firearm from discharging

The present disclosure generally relates to a bolt catch device that prevents the bolt of a bolt carrier assembly of a firearm from moving to its forward position so as to prevent the firearm from being discharged until the user manually moves the bolt catch. The bolt catch is mechanically coupled to the selector of the firearm via a linkage, so that the bolt catch can be moved by way of the selector. This feature can prevent a self-loading firearm that otherwise could function on a semi-automatic basis from operating in such a manner.