Patent ID: 6938445

Claim:
A mortise lock having a high security and tamper proof visual status indicator to show whether a door is locked or unlocked comprising: a door having an outside and an inside; a mortise lock positioned in the door comprising outer and inner handles for extending or retracting a latch, a mortise lock input on the outside of the door for changing the mortise lock from an unlocked to locked position employing a deadbolt and a mortise lock output in communication with the lock input for extending or retracting the deadbolt, a deadbolt throw lever blade shaft extending from the inside of the door which shaft extends into the mortise lock output; a visual status indicator comprising a rotatable indicator spindle axially aligned with the deadbolt throw lever, a housing having a top, bottom an right and left sides and an indicator slide in the housing wherein one end the indicator spindle is inserted in the mortise lock output and the other end is in communication with the indicator slide which slide moves linearly horizontally sideways between the right and left sides of the housing in response to the rotation of the mortise lock output and the indicator spindle when the door is locked or unlocked and which shows whether the door is locked or unlocked through an opening in the indicator.