Master Huang opens the company to tell you the

AB key lock, it has two kinds of A. B keys. It is a kind of lock made up of the structure of a bullet (the depth of a pit is different from that of a flat key). There are also called 'carba lock' and 'computer lock' and also called 'partial mouth lock' and 'Baili lock'. The function of AB key is that when people install the lock, the owner can give a key to the house fitters for them to use when they enter and exit the house, so it is also called 'fitment key'. When the decoration is completed, the owner does not need the decorator to enter the room. After the owner inserts the B key into the lock hole and turns the lock cylinder, the a key loses the function of unlocking. Therefore, the B key is also called 'the owner key'. A. The advantage of B key lock is that it can meet the needs of people to decorate the house. It can avoid losing the key to open the door when the decoration is busy, or the person with a bad intention can copy the key to open the door when the decoration is busy. It may avoid the unsafe factors to the owner after the decoration, and it can also avoid the trouble and cost caused by the safety and lock change after the decoration, so it is welcomed by people. The difference between two kinds of AB keys and the working principle of lock 1. For the sake of people's easy to distinguish, 6 B keys are sealed in transparent hard shell, and 2 a keys are hung outside. Some AB keys are different in color. Two a keys are yellow and six B keys are white. The back of the 6 B keys is provided with the instruction manual. The owner should read it clearly before use, recognize the use methods of the two keys, do not mix them up, and avoid improper use of the two keys. 2 if the two AB keys are compared and carefully observed, experienced people will find that one of the seven pits on the key is different (ordinary people don't pay much attention, think that there is no difference between the two keys). Both the deepest pit of a key and the shallowest pit (even flat, without pit) corresponding to B key, are generally the positions of the 7th or 1st bullet. At this point, I think the expert must have some ideas in mind, so I will remind the owner a to take back the key when it is used up, and keep or destroy it properly. 3. The structure of the marbles in the marbles chamber corresponding to the pits with different depths of AB key is special, and a φ 1mm steel ball is installed between the upper and lower marbles. When key a is used, the height of the lower bullet in the bullet chamber plus the height of the small steel ball is exactly flush with the lock cylinder, so the lock cylinder can be turned to unlock with key a; When key B is used, the small steel ball can be pushed out of the lock cylinder, that is to say, the lower ball is flush with the lock cylinder at this time, so key B can also turn the lock cylinder to unlock the lock (this principle is the same as the sub master key system). When the lock cylinder rotates at a certain angle, the small steel ball will fall into the blind hole cleverly designed on the lock cylinder in advance under the effect of the upper spring (this is the same as the sub master key) Some people call this small blind hole a trap, which is very appropriate. The diameter of the blind hole is larger than that of the small steel ball, but smaller than that of the bullet. Otherwise, the bullet will fall down and lock the lock cylinder. Once the small steel ball falls into the blind hole, it can only rotate with the lock cylinder, and will not run out of the blind hole, which will not affect the use of key B. However, when using key a, because there is no small steel ball, the lower shell in this billiard chamber cannot be flush with the lock cylinder (the height of the small steel ball is different), and the lock cylinder cannot be turned to unlock.