Remember how unenviable position was one of the heroes of the book of Ilf and Petrov “the Twelve chairs”, when he slammed the door with an English castle? Of course, tragicomic the described situation is presented in a slightly grotesque form, but still… there are cases when the owner of the door lock with automatic latch we have to sneak into their apartment through the window or through the door.
To avoid such cases, I propose to make a simple device — a metal damper of steel plates with thickness of 0.5—1 mm with two holes. Over the top, Ø 2-3 mm, the damper is hung on screw or a nail in the doorframe and for the lower bound line with a length of 15-25 cm With the door open the flap under its own weight closes the hole in the jamb and does not allow the lock to work. To the door closed, it is necessary for the line to lift the flap — it does not remember the key is virtually impossible.
KHOKHLOV, Saratov