Vault Door Electronic Lock Retrofit and Emergency Release Fabrication

A contractor contacted us regarding a plate vault door in a customer’s basement. The customer wanted to have it retrofitted with an electronic lock. I went over to the customer’s home and saw the door as seen in photo 1. Photos 2 and 3 are of the inside of the door. The mechanism is exposed. This safe door has no back panel. This type of door is referred to as a skeleton door. I had recommended to the contractor that an emergency escape mechanism be installed on this door. In addition to allowing an emergency opening should someone become locked inside, this would allow the room to be used as a panic room.

Photo 1

Photo 2

 

Photo 3

 

The contractor and customer liked the emergency release idea so they agreed to have me fit the mechanism to the door (in addition to the electronic lock). As a side note antique vault doors in general do not have emergency release mechanisms.

To truly be an emergency release, the mechanism would need to be able to be operated without the use of any tools. We decided on the use of quick release pins. These quick release pins can be removed from their holes by depressing the button in the center of the head of the pin while pulling using the index and middle finger underneath the pins shoulder.

The sizing of the hole that the pins fit into is critical. If the hole is made too sloppy or inaccurately, the pin will wobble and not hold the locking block tight to the door mechanism. This could cause premature wear or damage to pins or worse cause them to fail allowing the door to unlock.

In order to create the holes accurately, I first drilled the holes undersized and then used a specific size reamer to bring the hole to the exact size. This was all done in our small milling machine as seen in Photo 4. If we would have used a drill bit alone, the holes would have come out too large.

Photo 4

 

The quick release pins are what attached the locking block to the carry bar of the vault door. The carry bar is the vertical bar that the door bolts are connected to. Photos 5, 6 and 7 are of the modification made to the carry bar and the lock block I fabricated. The carry bar needed to have very accurately placed holes to line up with the holes in the locking block. This could not be accomplished at the customer’s location. I removed the carry bar from the vault door and brought it back to the shop to be modified. Photo 5 shows a section of the carry bar that was cut out and a new section that was welded in. The new section had mating holes that lined up with the holes in the locking block. The mating block was fabricated on the milling machine at the same time the locking block was. Photo 6 shows the locking block alongside the carry bar. Photo 7 shows the carry bar refinished to look presentable.

 

Photo 5

 

Photo 6

 

Photo 7

Photo 8 shows all of the components installed in the door. The quick release pins are installed in the carry bar and are holding the locking block in place. The locking block butts up against the electronic lock bolt, which is in the retracted position. The electronic lock is installed on a mounting plate. The black plate (relock trigger plate) mounted on the back of the lock holds a relocking device in its neutral position. Should the plate come loose or the lock knocked off the door, the relocking device will engage keeping the door shut.

Photo 8

 

To activate the emergency release, the quick release pins are pulled causing the locking block to drop to the ground. The carry bar can then be pulled back allowing the door to unlock.

Photo 9 shows the outside of the door with the electronic keypad attached.

 

Photo 9