This is a fine example of a circa 1870 Sargent & Greenleaf Automatic bank lock. The lock has four wheels and a roller bolt. Note the engraved decoration on the case and mechanism, togther with blued steel screws. All signs of quality.

An important feature in this lock is the anti-manipulation design, over a 70 years before the ' invention ' of manipulation.

Sargent & Greenleaf Automatic Bank Lock-sgauto1.jpg

The picture above shows the lock with the drop arm held off the wheel pack in the locked state (click on any picture for a higher resolution version)

Sargent & Greenleaf Automatic Bank Lock-sgauto2.jpg

The picture above shows the lock with the drop arm being released, this would only occur in one position per revolution of the dial. Without going into detail this action greatly increases the time & complexity of the manipulation process.

Sargent & Greenleaf Automatic Bank Lock-sgauto3.jpg

The picture above shows the lock in an unlocked (bolt rotated) condition.