Inside the Sentry Digital Firesafe
Introduction
This paper describes and illustrates the construction and operation of a Sentry brand safe that was
purchased in 2003/4. This small safe opens using a key and a code entered on a digital keypad. This paper
is not a replacement for the instruction manual, but is information designed to help in understanding the
operation and in maintaining the unit. This information is provided for your use only, with the
understanding that there is no warranty that this information is complete or accurate. All work done on the
safe by you is at your risk, and may void any warranty.
Operation
The safe door is secured by six deadbolt latches that engage between the door and the safe, two on each
side, and one each on top and bottom. Here’s what is hidden inside the door: The six latches are geared
together via a wheel gear that operated by the entry handle. Two interlocks prevent opening the door -- a
key operated pin block and a solenoid operated by the electronic combination. When the door is open,
another mechanical latch interlock holds the door latches retracted. (See photos at the end of this paper
showing all items located inside the door.)
To open the door, insert the key, turn CW and pull out the cylinder, thus withdrawing the pin block inside
the door. This removes one of the blocks on the door mechanism. Remove the key if desired. If the key
mechanism is pushed in (key or no key), the cylinder latches "IN" and activates the pin block.
To remove the second interlock (the solenoid), enter the combination code. When correctly entered, the
electronics causes the solenoid to operate, withdrawing the solenoid block on the door mechanism. If the
door is not opened in about five seconds, the solenoid releases, and the combination must be reentered.
(NOTE: low batteries or bad battery contacts can interfere with this step. Be sure your batteries are fresh.)
At this point, the handle can be turned down (CCW) which rotates the interior wheel, which via rack and
pinions withdraws the six door latches allowing the door to open. If the door is fully opened while the
handle is down, a simple leaf spring presses the lower right door latch (lower left, interior) toward the front,
and the latch arm drops over a slight ledge where it is help by the spring. This prevents the handle from
rising and the door latches from springing back to their outward engaged positions. When the door is
closed, a plastic pin then presses inward on the door, lifting the latch support, and releasing the latch,
allowing all latches to engage and the handle to rise.
Access to the door mechanisms
When the door is opened, the inside of the door is a plastic panel with key hangers and an envelope slot.
The plastic panel is a pain to remove. First, operate the lock to retract the door latches as far as possible.
Facing the back of the door, along the left inner edge you will find two plastic dimples. Press the upper left
one inward, and insert a putty knife between the door and panel and pry the panel gently around the upper
door latch and the plastic dimple. Do the same at the lower left. Then pry the bottom of the panel around
the bottom door latch. Move up the right side of the panel. Here there are no dimples showing, but they
are present inside, so you will pry the panel past them. Finally, do the top of the panel.
As you remove the panel, go slow, be careful: the panel has projections that hold various of the mechanism
parts in place. When you move the mechanism or touch things, be careful not to disturb their positions or
remove parts until you have figured out how it works.
Maintenance
•
Check that there are no burrs on the solenoid plunger that would cause it to stick in either position
and that it works smoothly.
•
Oil the key and housing so that it operates smoothly
