القفل ذو المحبس - الأقفال الأسطوانية .. الآلات التي نستخدمها كل يوم وكيف تؤدي عملها

Lock with a trap - Cylinder locks .. The machines we use every day and how they work

Lock with a trap:

The trap is a small metal piece fixed in the lock case. When you put a regular key in the keyhole, and then start turning it, the key tongue collides with the trap, thus preventing the key from moving any further and the door cannot be opened. In order to open this lock, a special key must be used, a key with a specific cut that is included in the design of the key tongue. This cut allows the tongue to move constantly without the trap standing in its way, until it reaches a position where it can push the bolt back.
A lock with a trap can only be opened with a key with a suitable cut and in a suitable place.

Locks with traps are designed to be equipped with several traps, so the appropriate key should be equipped with many teeth.

Since it is easy to place the traps in different positions inside the lock, it is possible to design many different locks, each with a special key.

“We have at last found a lock that will protect us from thieves,” said the locksmiths. But the thieves did not say so, for they soon discovered that it would be much easier for them to design a key that would not be hindered by these locks at all, because it would bypass them all in spite of them. This key is called a lock-screw because it has a very thin tongue (finger) that can often bypass the obstacles and locks that an ordinary key encounters when it turns and turns. Thus this thief-proof lock was transformed into something else that had no connection with this name.

Cylinder Locks:

Here improvements entered a new phase with the invention of the cylinder lock. This lock was invented by Linus Yale in 1848. It is the most common and widespread type of lock at the present time. Its immunity against thieves has reached a degree that no other lock can reach, unless you can spend hundreds of pounds to make a lock for a safe in a bank. The cylinder lock performs a very important function in normal use, because its design prevents the design of a key similar to it or a screen (screw) that fits it or enters it. Let us now study the way in which this lock works.

The best way for us to study it and understand the way in which it works is to disassemble a lock of this type and extract its parts, without losing any part of it. The next most important way is to study its operation by means of a set of illustrative drawings. This is what we will do here.

Figure 1 shows a circle with a ring around it. Each has a hole cut in it. We will see why these two holes exist in a moment. Notice that the circle can rotate inside the ring. But if we put a straight piece inside these two holes (the hole of the circle and the hole of the ring (Figure 2), the circle will be closed in the ring. The circle will remain closed even if this straight piece is cut into two parts, as shown in Figure 3. However, if we push these two straight pieces to the position shown in Figure 2, the circle can be rotated. Thus, the lower straight piece moves and rotates by means of the hole of the circle, while the upper part of the straight piece remains in the hole of the ring. Figure 5 shows how the circle rotated a partial rotation.

We see from these illustrative drawings that the circle and the ring can be closed together by means of two pieces, and we also realize the method of opening them if we push these two straight pieces upwards until they reach a certain position. In this particular position, the circle can rotate, but if the circle is in any other position, it will be closed. We will study below the method by which this idea is used in the cylindrical lock.

Before you is a front view, i.e. ( Front section of a cylindrical lock (Fig. 6) of the type that is installed on your external door. This lock contains a circle fixed inside a ring. If you remove the lock completely, and then take a longitudinal section of it, this section will appear to you as in (Fig. 7), and you will be able to distinguish five holes drilled in the ring, which fit five other holes in the circle. All these holes perform the same function as the holes in the ordinary circle and ring. In other words, we consider these holes to be the distances that fit and are compatible with the straight lines. In each hole there are two straight lines, and you can see that these lines are all of different lengths. Notice also that these straight lines are in a position where the circle is considered closed in the ring. After that - we open this lock.

The way to open it is to insert its special key (Figure 8). This special key has five teeth cut into its edge. When the key is fully inserted, these teeth push the straight pieces and put them in a position where they cannot block the path in front of the circle and prevent its rotation. The only key that can perform this operation is the one whose teeth are raised to a height that enables these straight pieces to take the correct position.

As for other keys, they leave one or more of these straight pieces in a position where they are closed and thus prevent the circle from rotating.

Try to think of a way to design a lock screen (extinguisher) that fits a cylindrical lock, and you will not be able to (after thieves tried this attempt and failed), because the straight pieces are made of different lengths, and therefore not a single tooth of the key’s teeth can lift each of these different lengths until it reaches its correct position.

As for the rest of the mechanical assembly of the cylindrical lock, it is very easy (Figure 9). When you use the right key in the right place, the circle can turn. This circle moves a finger (a tongue suitable for a bolt). Here the bolt slides in or out of the fixed receiver. In this way the door closes or opens.