1. Because the safety bolt button inside the door is loose, too much force is used when closing the door, and the safety bolt is shaken down. The lock cylinder can be turned with the original key, but the door cannot be opened.

2. Some people have something to do at the door because someone is at home, so they first hit the safety latch and forgot to hit it for a while. When closing the door, they forced the latch to close the door forcibly without contracting the diagonal tongue.

3. It is because there are ignorant children and elderly people with Alzheimer's disease who accidentally put the safety plug on at home, and they will not open the safety plug, causing people outside to open the lock with the key. The door lock still cannot be opened because the safety plug is on the door. Open the door.

4. Yes, there is another situation where someone is thinking of *** or gas poisoning, and cannot open the door for a sudden illness, etc.

The above situation occurs in several types of anti-theft doors. There are ordinary three-section split locks (three-safety door locks) and automatic door locks (self-lever locks) and AB-Kaba mortise door locks. Method for your reference.

The three-insurance split door lock has a safety bolt and cannot be opened with the key. Solution:

Three insurance anti-theft door locks There are two types of safety bolt buttons on the lock box inside the door: one is a twist button, the other is a push button up and down, the latter method can only deal with button type insurance.

The above method can handle more than 90% of the faulty lock with the safety bolt. Another stupid method is to use an electric drill to drill a circle of eyes on the lock box with an electric drill on the door. After using the drill, you can directly see the fuse stopper inside, and then use the screwdriver to move the fuse. You can also install a special drill on the iron door on the front part of the electric drill. The circular multi-tooth drill clip for installing the lock clip hole is used to drill through the hole of the door lock. Press straight into the lock box on the back of the door. After drilling into a large hole, you can move it. Safety bolt steel sheet.

If the anti-theft door safety bolt is hit and closed hard, you can use a wooden tip made of a piece of stiff wood, use the side seam of the door frame to drive in, and press hard to squeeze the edge of the door to open a seam, so that the door The slanting tongue of the lock is separated from the lock box on the side of the door frame, and then a flat-head screwdriver or other auxiliary tools are used to pry the door outward or inward; if the security door is opened outside, the door must be pressed tightly inward. If the door is opened inward, the door must be tightened outward. In this case, the principle of using this method to open is that the door can be closed hard, (the safety plug is lifted), and the door can be squeezed and opened. Under the circumstances, more than 80% can be opened by this method, and this method is not easy to damage the door frame and will not deform.