What is the ``Berlin lock'' where a rare ``key without a handle'' penetrates the door and locks it?

by karlherl

A typical key consists of a key blade part that is inserted into the keyhole, and a handle part that you grip and turn by hand. However, the Berlin lock, which was invented in Germany over 100 years ago, is known for its unusual shape , with blades on both ends .

Der Siegeszug des Doppelschlüssels - Wider die Säumigen und Vergesslichen | Berliner Mieterverein eV
https://www.berliner-mieterverein.de/magazin/online/mm1105/110519.htm

You can understand what kind of lock the Berlin lock is actually by watching the following movie that actually locks the door.

Berliner Schlüssel - YouTube


The actual Berlin lock looks like this, with a metal rod with blades at both ends.

A regular key can be passed through the hole in the handle to a key ring, but Berlin lock keys do not have a handle, so they cannot be secured to a key ring. Therefore, the blade is hooked onto the cylindrical part of the key ring so that it can be hung on the key chain.

The blades on both ends have the same shape, and both can be used to lock and unlock. Insert one end of the key into the keyhole ......

When I turned the key using the blade as a handle, it was unlocked.

If you look on the other side of the door, you'll see that the keyhole is shaped like the katakana ``fu'' character.

A key suddenly stuck out from the keyhole, as if penetrating the door.

Just go outside, close the door, and turn the key.

If you remove the key, the door will be locked.

The Berlin lock was invented in 1912 by Berlin locksmith Johannes Schweiger. Since the lock must be locked in order to remove the key, the Berlin lock has the effect of `` preventing people from forgetting to lock the door, '' and has been installed in more than 20,000 houses mainly in Berlin. In addition, it is said that the parts that fix the key of the Berlin lock were invented ``so that even drunk people could carry the key safely and easily take it out.''

However, because Berlin was divided during the Cold War that followed World War II, it became difficult to receive Berlin locks in some areas of Berlin. Also, as locking technology has evolved and safer locks have been made, it seems that new Berlin locks are no longer installed.

Still, Berliner Mieterverein , a political party that handles housing issues in Berlin, reports that ``As of 2005, we have confirmed that between 8,000 and 10,000 Berlin locks are still in use in Berlin.''