Drop-bolt door lock assembly

A high security defeat-resistant, drop-bolt lock assembly for a door, the lock assembly comprising:

• (a) a cylinder lock having an operating member extending therefrom,
• (b) a thick, tamper-resistant, substantially planar cylinder lock guard plate adapted to be mounted against one side of the door, the guard plate mounting on one side thereof the cylinder lock and protecting the same,
• (c) mounting studs integral with the guard plate and extendable through holes in the door when the guard plate is mounted against one side of the door,
• (d) a drop-bolt assembly positionable on the other side of the door and containing mounting portions on a housing thereof,
• (e) hardened, stud-protecting sleeves positionable to slip over each mounting stud, each sleeve having one end connectable with the guard plate on one side of the door and an opposite end connectable with the drop-bolt assembly on the other side of the door,
• (f) means cooperating with the guard plate studs, the sleeves and the mounting portions of the drop-bolt housing for connecting the housing, sleeves and guard plate and for securing the drop-bolt assembly housing to the guard plate studs and thereby integrally connect and secure the drop-bolt assembly housing, the sleeves and the guard plate to provide an integral connected assembly of the guard plate on one side of the door and the drop-bolt assembly on the other side of the door with the cylinder lock assembly sandwiched therebetween and protected inside the door.