Door Lock Lock (Customizable)

thingiverse

This probably needs some explanation. First! This is not a lock in the conventional way. It does not increase overall security, but prevents people with keys from entering. It's more an adapter to turn a bi-directional door lock into a uni directional door lock. In simple words, if you place this bracket inside, no one can unlock the door outside using a key. From outside it looks like the key doesn't fit anymore, as it is impossible to turn it. I'm not a lock expert and have no idea how the internals work, but on my door the key inside rotates when you turn the key outside. (Dual cylinder lock?) This is the requirement to use this bracket. It simply fixes the key inside so you can't turn another key outside. Once you slip it over the door handle, plug in the key from inside. The slot in the bracket allows you to insert it but not to turn it. Push the black handle on the bracket upwards and you're able to turn the lock from inside as normal. This lets you lock/unlock the door without removing the bracket. Once the door is locked using a key, move the bracket down and the slot prevents the key from being turned. From inside as well as outside. No one with a key can now open the door from the other side. The source file is included, so you can adapt my design for your door/handle/key dimensions if needed. But it's not that complicated to design it from scratch. In fact this is some old design I made over a year ago, when I started using FreeCAD. I suggest using a simple hard paper mask as a prototype and design the final design on that later on. Warning: Don't leave and lock a building with a key and the bracket installed inside. Even if you can lock the door, the bracket may slide down onto the key later on and you're locked out. If you want to keep the key inside and the bracket mounted, then push the bracket sideways and plug it in so it's not embraced by the adapter. I'm not responsible for you being locked out.