Diebold 180-33
It is a 3 wheel, key change, manipulation resistant safe lock. The way in which the manipulation resistance is achieved is very simple and elegant, compared to some other manufacturer's designs.
It functions almost identically to a regular group 2 spring fence lock, like the Diebold 177-22 or a S&G 6730 etc.
The difference is the manipulation resistance mechanism. Once the combination has been dialled L-R-L, the dial is turned right to 0, then it is pushed in before continuing to dial right to retract the bolt.
Unless the dial is pressed in, the lever nose rides the outer edge of the drive cam, which has no gate & therefore the fence never touches the wheel pack, and there are no contact points.
When the dial is pressed in, it's movement is transmitted to the drive cam, bringing the drive cam gate in line with the lever's nose. If the gates are all under the fence & the drive cam gate is under the lever's nose, the lever can drop & the lock can be opened.
The dial can be pushed in at any point on the dial, however when the dial is depressed, the drive cam is disengaged from the wheel pack, preventing any movement of the wheels when the dial is depressed.
There is no seperate change index on the dial, the dialling index also serves as the change index.
There is a small track containing ball bearings on the back cover, that bears against the drive cam.
The gates in the combination wheels are shaped very much like those in the S&G 8400 & this makes for a close fit between the gates and the fence, giving the lock very fine dialling tolerances.
The copper plate is the relocker & is identical to the relocker in the Diebold 177-22.
The dial (for some reason the image has been rotated through 90degrees when uploading, the opening index should obviously be at 12 o'clock) :
Inside the lock :
Drive cam gate visible, with the dial at rest :
Drive cam gate visible, with the dial depressed :
Correct combination entered, dial depressed & lever has dropped :
Inside of back cover :
...Mark