Patent ID: 7757420

Claim:
A replacement mainspring assembly for selectively locking a semi-automatic handgun: said replacement mainspring assembly comprising: a mainspring housing configured to be received in an associated semi-automatic handgun to replace an existing mainspring housing without modification to the associated handgun; said replacement housing including a pin opening configured to align with an associated pin opening in a handle portion of the associated hand gun, said pin opening being shaped to receive a locking pin, said locking pin maintaining said replacement assembly in a received position within said associated handgun when said locking pin is positioned in said associated pin opening; said replacement mainspring assembly further including an elongated passage shaped to receive a spring assembly, said spring assembly including a spring with a first end and a second end with a mainspring cap on said first end shaped to receive an associated hammer assembly of the associated handgun and a retainer pin on said second end; a locking mechanism having at least two combination disks, said locking mechanism moving between a locked condition and an unlocked condition, when in said unlocked condition, said associated handgun being freely operable and said locking pin being selectively removable from said retainer pin, when in said locked condition said locking mechanism engaging the associated hammer assembly to restrict movement of the associated hammer assembly and prevent operation of the associated handgun and engaging said locking pin to prevent removal of said locking pin from said pin opening thereby preventing removal of said replacement mainspring assembly from the associated handgun.