The humble door-locking deadbolt has suffered from a severe failure of innovation and imagination in the last 100 years.
Specifically: most deadbolts have exactly two positions (Figure 1):
- Open (door can be opened from either side)
- Closed (door requires a key to open from the outside or a switch to be operated from the inside)
In some locations, especially in Europe, the deadbolt is even worse, as the closed position is:
- 2b) Closed (door requires a key to open from the INSIDE as well). Somehow this is allowed by the fire code.
In either case, a key is required in order to lock the door, which can be annoying if you’re leaving in a hurry.
Fig. 1: A regular mechanical door lock (deadbolt) has two intuitively obvious—but primitive—settings.
Many door locks (but not deadbolts) also have a setting where the door can be set to automatically lock when pulled shut.
Additionally, many doors have two locks: a deadbolt and a regular door-handle lock. But there’s no reason we can’t combine the two locks into a single multi-function “dual lock” (Figure 2).
Fig. 2: This updated “dual lock” handles both the deadbolt and door handle lock functionality, together in one convenient location.
Now the home’s occupant only needs to operate one lock when they want to open the door (instead of needing to unlock the deadbolt before using the key in the normal lock).
There’s no reason we can’t update this lock with even more options. See Figure 3 for an additional proposal.
Fig. 3: This lock for the truly security-minded allows the door to be completely secured from the outside.
When the lock is in the lower-right position (as depicted), even the key cannot open the door from outside.
While this is not a common lock setting, the front door to the British Prime Minister’s office (10 Downing Street) works in this fashion (it can only be opened from the inside).
Next time you’re thinking of doing some kind of home improvement, consider upgrading your door locks!
PROS: Simplifies the state of door locks and reduces the otherwise ever-expanding number of keys that are present in daily life.
CONS: Puts “big deadbolt” out of business.