Abstract: A double hook-bolt unit lock includes a lock barrel having a revolving rod connected thereto to cause a cam wheel assembly to move simultaneously so as to drive the stop keys of a stop frame assembly away from the upper notched portion of a brake frame assembly and to let the cam wheel assembly move the brake frame assembly rectilinearly via a lower notched portion of the frame assembly. By means of the push force from L-shaped guide slots of the side plates of a lockcasing and the guidance of oblique guide slots of a brake frame assembly, the two L-shaped bolts which are movably connected to the brake frame assembly are driven to smoothly into respective locking positions to lock the door.

Abstract: A double hook-bolt mortise lock includes a cam form tumbler plate assembly comprised of a plurality of cam form tumbler plates driven by the steps of a key to define a space passage for passing therethrough of the key into a brake notch to further drive the cross bar of a main brake frame to move from one stop hole to the other. During movement of the main brake frame, an auxiliary brake frame is carried by means of two idle gears to make a rectilinear motion toward or against the main brake frame so as to drive the gears of two hook bolts to rotate, by means of the rack portions of the main and auxiliary brake frame, to further let the two hook bolts lock up with or lock from a striking plate.