Guide to cylinder mechanisms (lock larvae). Door lock device: diagrams and design features What does a larva mean in a door lock

The larva of the front door lock is the most common cause of its breakdowns and the most favorite object of action for burglars, because. locks with some types of larvae, which are considered reliable in the popular concept, are actually silently opened in 1-3 minutes. This article describes how to replace the lock cylinder with a cylinder mechanism yourself. If the lock sticks, then this will save a considerable amount. If the degree of secrecy of the castle is unsatisfactory, then again, its increase can be done by replacing the larva, because. their installation dimensions and interface schemes with the lock mechanism are standardized.

Note: for thieves-burglars, the critical time for opening the lock is 5-10 minutes. Longer transported - the probability of "getting caught" increases dramatically. In this case, it is more profitable for the villain to look for other ways of penetration or to completely abandon the “case”, unless he knows in advance that there are expensive and compact quickly liquid assets “at the hut”.

Is it possible to?

Do-it-yourself replacement of the front door lock cylinder is possible if it is with a cylinder mechanism of one kind or another (see below). You can determine this by the type of key: if it is similar to those in Fig. further, then an entry-level home master can replace the larva in the castle without the use of special tools. Irreversible opening of the lock from the outside is also possible in some cases, see below. This may be necessary if the lock is jammed or the key is broken while trying to unlock the door, and there is no one inside who can open the lock from there.

Types of cylinder mechanisms

In terms of the ratio of the achievable degree of secrecy, reliability and cost, only trigger locks successfully compete with cylinder locks, slightly inferior to cylinder locks in terms of vandal resistance. The key of a trigger lock is similar to a 2-bladed key from a lever lock, but it does not actuate the moving plates (levers), but the moving elements - mechanical triggers. Finding their positions, in which the bolt of the lock is unlocked, is extremely difficult and using the most modern methods. Trigger locks are very expensive and for a house/apartment not stuffed with gold, jewels and small antiques, The cylinder lock is optimal for the front door.

The larva of a cylinder lock is also called its core or cylinder mechanism. This is a characteristic assembly of a cylinder lock, which is absent in locking devices of other systems. The peculiarity of the cylinder lock, firstly, is that it is possible to change the lock cylinder of the front door of this type from the inside without touching the door itself; the work process takes no more than half an hour. Secondly, in many cases it is also possible to open a stuck lock from the outside without damaging the door.

The keys in fig. above from locks with a trace. types of cylinder mechanisms:

• Pos. 1 and 2 - classic English with a single-row needle (pin) mechanism.
• Pos. 3 - with a 2-4 row larva (pin or disk) under a cross key.
• Pos. 4 - with a disk mechanism.
• Pos. 5 - "punch card" from a larva with counterpins (counter-angles).

The larva of the lock is unlocked by inserting into the well and, possibly, by the initial turn of the key. Its full rotation through the driving element of the larva (see below) and (in some types of locks) transmission parts pushes the bolt of the lock, which pushes / retracts its tongue (tongues). Larvae for overhead and mortise door locks with cylinder mechanisms of different types are arranged differently; resp. the procedures for replacing them also differ.

Note: it would be more correct to call the keyhole in the cylinder lock a nest, because well by definition is something through.

Needle

The principle of operation of a cylinder lock with a simple 1-row (English) larva is shown at the top left in fig. The cutouts of the standard inserted key shift the spring-loaded split needles (pins) so that the lines of their connectors coincide with the dividing line of the cylinder (rotor) and the housing (cage). Now the cylinder can be turned with a key. The mustache of the cylinder will then turn the leash with a cam (slide with a finger). The cam (finger) will push the bolt and the lock will open / close.

Cylinder mechanisms of any degree of complexity are produced in the next. design version:

• The key-handle (pos. and in the figure) is the most convenient and common type.
• Key-key (pos. b) - used when the door must also be locked from the inside. For example, in the door of the common lobby of several apartments.
• Semi-cylinder (half cylinder, half core, pos. c) - is usually placed on the entrance doors of non-residential and utility rooms.
• Pos. g - under the cross key. It is considered a mechanism of increased secrecy, but we will talk about this later.

more reliable

The main disadvantage of a simple English cylinder is the low degree of secrecy; the number of its combinations rarely exceeds 1000, so if the house is out of the way, the thief will have time to open the lock with a simple selection of keys. Further, a master key and 2-3 lever probes enter the well of such a lock, with which the larva is silently and reversibly unlocked in 2-3 minutes. Finally, if the house is also on the outskirts, pins can be made in the same 2-3 minutes. drill, see below.

Highly reliable pin larvae are provided with an anti-burglary hard alloy rod (from drilling, indicated by a green arrow in pos. I of the figure) and additional rods (blue and purple arrows) that prevent the use of a thin thief's tool. But the degree of its secrecy remains low, so honest locksmiths, at the request of the owners, prefer to open such locks from the outside by selecting keys.

In larvae with counterpins moving under the action of gravity (pos. II), secrecy increases by orders of magnitude: if one row has only 100 combinations, then together it will be 100x100 = 10,000. » no need: to take the lock with a tool, the counterpins interfere. It is possible to quickly open such a lock from the outside only by drilling with a diamond drill. The keys to locks with counterpins (pos. IIa) were called punched card or computer keys for their outward resemblance to antediluvian storage media. The lack of larvae for a punched card key is the small stroke of the pins. Increased precision in the manufacture of the mechanism is required, which makes it more sensitive to contamination. Therefore, in country houses with such locks, larvae are used on the same principle, but with a comb key, see at the end, about choosing a new larva.

Disk

Lock larvae with a cylinder-disk mechanism (pos. A in the next fig.) are most often used in overhead apartment locks, but sometimes in inexpensive mortise locks.

The principle of its operation is illustrated by pos B:

1. The angles α between the axes of symmetry of the borehole and the sampling holes of each of the discs that make up the code packet are different;
2. The angles α of each disc correspond to the bevels on the key stem;
3. The inserted key is turned slightly;
4. The select wells converge into a groove (pos. B);
5. With a further turn of the key, the finger falls into the groove so that its middle falls at the junction of the rotor and the holder;
6. Further, when the key is turned, the finger pushes the clip, which actuates the bolt.

The real advantage of the disk lock cylinder is one: it is very difficult to break the key. The disc mechanism is not very sensitive to contamination, and with a non-standard key, the code package can be turned indefinitely. Therefore, it is advisable to supply the doors of rooms with disc locks that have been unattended for a long time and are unattractive for burglars: country houses, sheds, garages. An amateur craftsman can also come in handy with the relative ease of recoding a disk lock with their own hands. For example, if the key is lost under suspicious circumstances or the keys were transferred by the previous owners. Instead of spending money on a new lock, you can sort out the package and make new keys from blanks. How a disk lock is recoded at home, see the following. video.

Video: transcoding a disk lock yourself

The disadvantages of a disc lock in the case for storing valuables are more than serious. The first is as small as that of plain English, the degree of secrecy. There are disc locks for sale with a cross key (see fig.), But they are just as unreliable as pin locks (see below), but they are more prone to contamination than punched card locks. Secondly, the disc lock well is wider than that of the English one, and it is even easier to stick special tools there. A “clean” opening of a disk lock for the purpose of an unspoken search (so that the owner does not guess and a secret visit) takes no more than 5 minutes, and a thief's - 2-3 minutes.

Thirdly, the locking and unlocking mechanisms of the disk lock are separated, because. it cannot be locked by turning the key back. The locking is actuated by a spring-loaded flag protruding under the tongue. When the door is closed, the flag is recessed and releases the latch (pawl) of the bolt pressed by a stronger spring. Therefore, the owners of an apartment with a disk lock at the entrance are very likely to find themselves in the position of engineer Shchukin before meeting with Ostap Bender.

Fastening and opening

Fastening of overhead larvae and parts of inexpensive mortise locks is often done lengthwise (longitudinal, axial, pos. 1 and 2 in the figure). The bolt leash rotates with a freely suspended lamella (black arrows). To remove the lock cylinder with axial fastening from the inside, you must first remove the lock body and unscrew the fixing screws, after which the cylinder is taken out. Outside, the larva with axial fastening is torn out without a key with a crowbar or a mount with a sharp end. If the opening is master's, and the door is not steel and it is reluctant to mangle it, then you will have to drill it out. The axial larva of the disk lock must be drilled on both sides of the well (red arrow in pos. 1), and the pin - in the places indicated in purple in pos. 2. They are located symmetrically on both sides of the rotor at the level of the upper edge of the well (2-sided red arrow).

More reliable against breaking lock cylinders with side fastening, pos. 3. When opening it from the outside, it is useless to drill a bolt or try to knock out the larva in order to push the crossbar with a screwdriver: the cam of the leash will interfere (green arrow in pos. 3). In this case, the only way out is to drill the pins (see below). From the inside, it is possible to pull the larva out of the lock with a side mount for replacement without much difficulty:

• Remove the inner handle of the lock-latch (see below);
• The outer handle of the lock is pulled out along with the square axis;
• Remove the inner lining of the lock;
• Find the head of the fixing screw under the tongues (green arrows at pos. 4 and 5);
• Turn out the screw;
• Take out the larva inside.

How to remove the handle

Difficulties in this process can only be caused by removing the lock handle (if the key has not broken in the lock, see below). Its mounting on the axis is possible as follows:

1. On both sides of the neck of the handle, the ends of some kind of steel rod are visible, polished flush. The upper end, when viewed under a magnifying glass, is wider than the lower end - a through conical pin.
2. A rounded head without a slot is visible - a blind pin or a shaped bolt.
3. The head of a slotted screw is visible - a simple bolt.
4. One protruding end of the pin is visible - an old-style blind pin.

A simple bolt simply turns out. The old blind pin is pulled out with small end-cutting pliers (something like small blacksmith pliers) or side cutters with one-sided sharpening (without bevels on the smooth sides of the jaws). The conical pin is carefully knocked out from the side of the narrow end with a light hammer and a spacer from a thin, rigid steel bar; e.g., a nail with a sawn end. You can’t beat with a sharp one: the end of the pin can rivet, and then it will have to be drilled out!

A head without a slot must first be checked: the pin behind it or the bolt. To do this, a rubber or PVC tube is pulled tightly over the head (so as not to spoil the view) and they try to turn it back and forth with small pliers. Turns in both directions - pin; it is taken out like the old deaf one, but in this case, you can still pry off the head with nail tweezers. If there is a shaped bolt behind the head (in this case, it will most likely be from below), then it will turn on one side and it will be noticeable that it turns out. Well, they turn it out.

If the lock sticks

It is better to try to open a faulty lock from the outside with a key, after all. a rusted larva can most often be repaired. The best way to unlock a stuck lock properly is to put 2-3 drops of brake fluid into the well. After an exposure of 1-2 minutes, the most rusty, but not completely broken lock, most often opens. Further, if the larva suits the secrecy, it can be sorted out and repaired, see the video guide:

Video: disassembly and assembly of the lock cylinder

If the key is broken

It is unlikely that it will be possible to remove the larva from the lock without drilling if a broken key is stuck in the well. The easiest way to extract its residue is a small black (phosphated) metal screw. White galvanized and wood screws are not hard enough. The hardware is wrapped in the gap between the rest of the key and the well; according to the principle of recoil, the broken one will climb out. If there are other ways, for locks with a very narrow hole, see for example. track. video clip.

Video: how to remove a broken key from a lock

How to drill

Since an ordinary citizen does not keep a set of tools for opening locks (we will still consider it a locksmith, not a thieves one), and you still have to change a jammed larva, the most affordable way is to drill pins. To do this, you need a drill from 3-4 mm; where to drill is shown in fig. below. Drilled needles will not fall down themselves, burrs and remnants of springs will interfere. Therefore, after drilling, insert any key or (worse) a flat screwdriver that is suitable for the profile (location of the longitudinal grooves) and turn, shaking, until the larva is unlocked.

Further, since the owner is not a thief or a secret agent, the time factor does not threaten him with a prison. Therefore, anti-burglary pins can be drilled with a drill bit. It will take a long time to transport: there are castles, the victorious one manages to get through them in an hour or more. You need to drill with a win with the lightest pressure so that the drill does not crumble. Larvae with counterpins under the key-punch card or comb will have to be drilled twice, at the top and bottom.

Replacement

Well, finally got out, damn! Now, what kind of larva to the castle should be bought to fit and be more reliable than before? With dimensions on the end, it’s simple: we take with us to the store a door lining with a window for the larva. If the lock with a larva is on an axial mount, it will also be necessary to measure the dimensions of the lamella so that it reaches the crossbar leash and enters it.

For locks with side mounting, the asymmetry of the mounting hole, pos. 1 in fig. Standard installation dimensions of the lock cylinder for a steel door are given in pos. 2, but there may be others. And the last - the type of drive of the crossbar: cam or gear, pos. 3. Cam configuration and gear module are also different. So it is better to take the old larva with you.

Which is better?

We will reveal to the reader a secret well known in certain (and by no means only criminal) circles: “top-secret” cross-key locks are opened instantly with a strong sharp turn of a strong Phillips screwdriver. The code elements (pins, disks) and the gaps of the clip metal between them are very thin in them. Simple English and disk larvae of locks, as it is said, are opened with a special tool in 2-5 minutes, which is less than the critical thieves' time.

The conclusion is simple: it would be best to buy a new lock cylinder for a city apartment with a punched card key, and for a country house - also a counter-pin for a comb key, see Fig .. If other possible ways of unauthorized entry into the house are stopped (good outdoor lighting, local security alarm , bars on the windows, a guard dog in a kennel or aviary; perhaps a system and registration), then you can sleep peacefully behind doors with such locks. How realistic is this in today's world?

One of the most popular, demanded, reliable and constantly developing systems of locking mechanisms is a cylinder. She was born just over a hundred years ago.

This system is easy to use, does not require extra effort when opening the lock, and in case of loss of the key, it is enough to replace only (the larva), without touching the entire locking mechanism. Another undoubted advantage of cylinder type locks is that all cylinders are compatible with locks from different manufacturers. If you need to replace the larva that will meet all quality standards, you should understand which cylinder is better. It is about how to choose the really best cylinder that we will talk about in this article.

What kind of cunning "beast" cylinder?

First, let's try to figure out what a cylinder is. This is a special device with which the crossbars are opened - the force of the key being turned in the keyhole is transmitted to the internal mechanism that ensures the movement of the valves. In addition, it is in the cylinder that all the secrecy of the castle is hidden.

The incredible accuracy and peculiarity of the cylinder structure allows only the “native” key supplied with the product to open the lock (most often there are from three to five “native” keys).

Cylinders are available in the two most popular colors to match locks and doors of any color:

• nickel-plated;
• brass.

Depending on the type of locking mechanism, cylinders come in two systems:

• key-key (a key is used to close or open the door from the outside and from the inside);
• wrapping key (outside the lock opens and closes with a key, and from the inside - with a rotary handle).

When trying to understand which cylinder is better, you should be aware that no matter how reliable the mechanism is, it needs the additional protection that it provides.

How to buy the perfect cylinder

There are many types of cylinders, distributed according to the level of secrecy and reliability, resistance to force. The main parameters that you first need to pay attention to:

• ease of operation;
• durability and wear resistance;
• reliability.

How wear-resistant the lock is depends on the quality of the internal components of the product, as well as the materials from which they are made. Be sure to consider the lubricant used in the device.

If we add here the assembly quality of the nodes and the entire device as a whole, then we can talk about the reliability of the mechanism. The higher the indicators of reliability and wear resistance of the cylinder, the lower the likelihood that at some point it may refuse to function or be opened with a master key.

There is no reception against scrap?

The reliability of the cylinder also depends on how effectively it can withstand force hacking options:

• drilling;
• knocking out;
• breaking;
• pulling out, etc.

Today, there are many developments that help counter any of the above options. First of all, they relate to the raw materials from which they are made - for example, it can be hardened steel or other hard alloys that are hardened. Almost no drill takes such materials.

Separately, we can recall the Mauer (Mayer) cylinders, made using a special “red line” technology, when, when trying to break the mechanism, only its front part breaks off, and the cylinder itself remains inaccessible to burglars, but at the same time continues to function reliably when using the native key.

Almost all cylinder models of the Mottura brand (Mottura), in turn, are equipped with a special knockout protection system, and therefore they effectively resist any method of force, except for drilling.

Most cylinder manufacturers offer consumers to purchase additional ones that will significantly increase the security of the mechanism and, accordingly, the safety of the premises.

Therefore, when determining which cylinder is better, do not forget about the overlays, which are distributed depending on the mounting option into two types:

• mortise;
• overhead.

The first type of lining is mounted on the lock. One of the most reliable products is the company,. These models are virtually unrealistic to tear off the door leaf, and therefore their protective properties are incredibly high.

Overhead protection is mounted on the outer door leaf. Although, they are often considered more decorative, since they provide protection from drilling only until they are torn off. The most popular products are Kale (Kale), Ritko (Ritko) and others.

Intelligent cylinder protection

One of the options for opening cylinders is an intelligent method, the essence of which is the selection of keys and master keys. Modern models of cylinders quite effectively resist this method, but not all of them. For example, cheap devices wear out fairly quickly, making them easy to open with any key.

In general, the burglary resistance of cylinders is distributed into several classes and depends on the time it takes an attacker to open. The most simple, weakly protected cylinders open in two to three minutes. A cracker needs at least half an hour to open expensive complex mechanisms. However, in most cases, the robbers simply do not have so much time. Therefore, if you really want to understand which cylinder is better, ask the seller for documentation related to the product. It must necessarily indicate the burglary resistance class of the mechanism.

To avoid opening the cylinder with a master key, manufacturers equip the internal secret part with false grooves, into which the master key falls. Quite common are small wells of complex design, into which it is extremely difficult to insert a master key.

Reliable cylinders must also effectively withstand the so-called automatic picks, which work on the principle of vibration, leading to the opening of the locking elements. In theory, even the most expensive and reliable model of a cylinder can be opened in this way, however, as practice shows, in fact it only affects inexpensive models, and even then not always.

One of the most common methods of opening locks is "bumping", when a pre-prepared key model is inserted into the keyhole, which is beaten with full force with a hammer or other heavy tool. As a result of such an impact, the pins and pins diverge, and it turns easily. Modern expensive models of locking mechanisms easily resist this method of hacking due to several factors:

1. A small keyhole, under which it is difficult to pick up a workpiece.
2. Robust internal components and assemblies capable of withstanding the increased force exerted upon impact.

There are many models designed to withstand bumping, but in general, many brands of cylinders withstand this method of breaking. For example, these are products from the following manufacturers:

• EVVA;
• Multi-lock;
• Cisa and others

The most popular hacking methods were listed above, but there are others. In practice, they are not actually used, since they have long become ineffective. Such methods include the use of acid, which, according to some, corrodes the internal filling of the mechanism. However, on the metal used in locks, under the influence of acid, a salt coating is formed, which does not allow the acid to have a further negative effect. In addition, the internal parts of cylinders and locks today are most often made of hardened steel or cupronickel, which are actually not affected by acid.

Big secret

When trying to determine which cylinder is better, be sure to specify what its secrecy is. This concept is often used to express the number of possible combinations of a cylinder created by its pins. According to manufacturers, the most reliable models cannot have less than a thousand combinations, and in elite, expensive cylinders, the number of combinations reaches several million.

In fact, everything is much more complicated, and many characteristics should be invested in the concept of secrecy, including:

• wear resistance;
• resistance to force;
• resistance to intellectual influence;
• number of cylinder combinations;
• the probability of opening the lock with similar "native" keys, etc.

In addition to the above characteristics, the secrecy of the cylinder is directly affected by the quality of its manufacture, which has a positive effect on its durability and reliability.

Why top hats for the people?

The easiest way to determine which one is better is to look at its cost. So, even a schoolboy can easily open the cheapest models in a matter of minutes by reading or watching relevant literature or video clips on the Internet. Quite often, the cheapest cylinders are sold even without packaging, indicating the manufacturer. Such products not only cannot improve the protective properties of the door, but also fail very quickly, which leads to the need to buy a new product and, accordingly, additional cash costs.

Buying a cheap cylinder is only justified if it is purchased as a temporary constipation. For example, when carrying out repair work in a newly acquired apartment, which in the future involves the purchase of a new door with a full-fledged, reliable lock.

For the front door to an apartment or house, it is recommended to purchase medium-priced cylinders. Models from this group of products are significantly superior to cheap products in terms of reliability and ability to withstand various hacking options. Even an experienced specialist will have to spend a lot of time on opening the lock, drilling or knocking out the method, making a lot of noise, which will attract neighbors or just people passing by. And even then, such opening options are not always effective, since hardened steel is used for the production of cylinders, which prevents the product from breaking. Given the use of modern reliable materials, medium-priced cylinders work flawlessly for many years, do not break and do not require replacement. Models of this price category are installed in at least 70% of doors.

The third category of cylinders, the most expensive, guarantees the maximum level of protection and safety. Only hacking geniuses can open them, of which there are not so many in the whole world. Cylinders of this type are able to withstand the power and intellectual method of breaking. Particularly durable materials, innovative developments used in the manufacture of locks of this type, can even completely block the device at the slightest attempt to break in, whether it is drilling or selecting master keys. Naturally, the cost of such cylinders, used in conjunction with specially designed ones, is incredibly high. It is recommended to install them only if you are confident in the overall reliability of the door, which can neither be broken out nor cut off its hinges. Otherwise, spending on expensive cylinders is not entirely justified and it is better to limit yourself to a locking mechanism of the middle price category.

We hope that now you can understand which cylinder is better and get a really reliable and durable mechanism. When buying a mandatory product, consider all of the above parameters and characteristics of the cylinders. Do not be guided only by the promises of the seller and the popularity of the brand that produces the mechanisms.

Removable locks for door locks have been invented for over 100 years and have proven to be one of the most successful inventions in this area. Why spend money on expensive locks when you can simply replace the front door lock cylinder. Today we will tell you how to choose and install a door lock cylinder.

The door lock cylinder is one of the most successful inventions in this area.

The locks in a wooden and in an iron door are almost the same, but installing a lock in a metal door is considered a more difficult task, especially if it is a safe-type design, so it is easier and cheaper to change only the larva.

But before replacing the larva in the door lock, you need to figure out what kind of mechanism is installed there. There are 3 types of such structures:

1. Disk;
2. cruciform;
3. Cylinder.

Cylinder mechanisms have several other names, for example, English, pin or pin, but the principle of operation, and the appearance of all these structures is similar.

The disk larva of the front door lock has a round keyhole and is opened with a semicircular notched key. At the end of the last century, it was considered reliable, but then the people figured it out and now disk larvae are not popular.

In fact, their only advantages are an affordable price and a simple replacement of the door lock cylinder.

Replacing the disc door lock cylinder is not difficult, but it is not reliable.

The next contender is the cross larva. Here the situation is about the same. Despite the fact that the key with 4 edges seems to be reliable, in reality the device of the larva is more than simple.

Robbers do not even need to drill it to open the cross mechanism without a key, they simply filmed or move the decorative trim and turn the mechanism with a powerful screwdriver or some similar device. So if you have such a mechanism, it is better to change the lock.

Cross mechanisms are considered the least reliable.

cylinder mechanism. It is also not particularly difficult to change the larva in the lock here, but over more than 100 years of development, the reliability of cylindrical heads has become several orders of magnitude higher than that of the two previous options. Plus, these mechanisms have several modifications.

The classic scheme of the English mechanism.

It makes little sense to dwell on the cross and disk mechanisms, experts do not recommend using them, but if such a mechanism is already installed, then you can watch the video in this article and read how to change or how to drill a larva in the locks.

By the way, if you have a so-called lever lock with a butterfly key installed, then there are no larvae at all, this is a completely different type of construction, here you will have to change the entire lock. True, there are lever models with restructuring for a different key, but their price is high.

It looks like a lever lock with a butterfly key.

The subtleties of choosing a cylinder larva

Before choosing something, you must first remove the lock and figure out which type of cylinder you have installed. The fact is that while the larva is in the door leaf, you will not understand anything, because visually they are similar and only removing mechanism, it can be accurately measured.

A few words about disassembly and replacement

How to remove the larva:

• Before disassembling the larva, it is advisable to lubricate, use ordinary engine oil for this, it can be found at any hardware store;
• First of all, when disassembling, insert the key into the keyhole and set the mechanism to the neutral position - open;
• Next, we disassemble the fixing system: just below the locking “tongue” (from the end of the canvas) you will find a screw - this screw must be completely unscrewed and removed;
• Now carefully pull out the lock cylinder in any direction.

How to replace the lock cylinder - step by step.

If the larva does not pull out, then try moving the key around the axis, perhaps the locking "dog" has not become in the zero position.

Do-it-yourself replacement of the front door lock larvae, however, like, the task is not difficult, step-by-step instructions, with all the recommendations are set out.

All cylindrical-type larvae are made according to a single international DIN standard, though there is also a RIM standard, but it is quite rare. Within these standards, there are 2 types of structures:

The front dimensions of the cylinder-type larvae according to the DIN standard.

1. Key + key - this is when keys can be inserted on both sides of the door leaf. The option is good because if you insert the keys into the keyhole from the inside, then it is no longer possible to unlock the mechanism from the outside;
2. Key + wrap - here the door is closed from the inside with a wrap. The mechanism is considered safer, since in case of an emergency, the doors are easier to open from the inside.

When choosing a lock cylinder, you need to choose the right size of the mechanism.

The level of secrecy of the mechanism depends on the number of pins, they are included in the cutouts on the key, repeating the pattern. The pins are located at the bottom of the head and are pressed against the key by internal springs.

In the economy class, no more than 5 pins are placed; in such mechanisms, the probability of selecting a key is limited to 10,000 options.

The mechanism with six pins is considered the most popular, here the number of selection options increases already to 50,000.

In the elite sector, manufacturers install more than 6 pins, plus some of them may have additional secrets. In these models, the level of secrecy starts from 100,000 options and can go up to several million.

The level of secrecy of the mechanism depends on the number of pins.

The simplest criterion for choosing a cylinder is its mass. When buying a mechanism, pay attention to the weight, so if the head weighs up to 100 grams, then you are dealing with a cheap fake and it will last no more than a month.

The low weight suggests that the parts of the mechanism were made of aluminum at best, and most often they are made of silumin, which is even worse. Save a couple of hundred and you can close the doors and be trapped. The minimum for such a mechanism is 180 - 200 grams.

When buying a cylinder, pay attention to the weight of the mechanism.

The main protection against drilling of the mechanism is hardened steel pins. Not a single drill, even a drill with a victorious soldering, can overcome such a pin.

Steel pins protect the lock from drilling.

There are larvae with the so-called vertical key milling, they are also called laser keys. Popular rumor ascribes an increased level of protection to these mechanisms, and so, there is nothing extraordinary in these mechanisms, you are being deceived, this head is unlocked as easily as an English one.

Among the robbers there is a hacking method called "Bumping", if explained simply, this is an elementary knocking out of the larva from the lock. A device such as a chisel is placed, and with one strong blow with a sledgehammer the mechanism is knocked out.

There are also several ways to protect against bumping. One of the most common is the installation of a double-sided steel spring, as in the photo below. Naturally, the manufacturer himself puts this protection.

One of the options for protecting the larva from knocking out.

Among the locks of the middle and elite class, the most reliable are mechanisms with magnetic pins. In this case, a small magnet is mounted in the key, and when the key is immersed in the keyhole, a certain pin reacts to this magnet. Traditional lock picks are powerless here.

Cylinders with a magnetic key are considered one of the most secure.

Often people judge the quality of a grub by its value. According to experts, mechanisms that cost 200 rubles should not even be paid attention to. Secrets for 350 - 400 rubles. already more reliable.

Determining the quality of a mechanism by its price is a good way, but not always reliable. From a particularly “greedy” merchant on the market, you can buy for seemingly normal money not the best product, so the price is to some extent a lottery.

Briefly about the manufacturers

The Mauer trademark is famous for its unique reliability, especially the developers have advanced in setting up protection against the so-called intellectual hacking, in other words, from master keys.

The vast majority of Mottura models are well protected from bumping, but they have another problem - the designers paid little attention to drilling out the larvae, which is no less important than insurance against knocking out.

Among our manufacturers, one can single out goods from the Asteks Trading and Riko trademarks, these brands have strongly pressed foreigners in the middle price niche in recent years.

Many professionals recommend installing a larva with good protection against drilling and master keys, and protecting the mechanism from knocking out with a separate armor plate, so you get more complete protection for quite reasonable money. Cisa and the aforementioned Mottura are leading among manufacturers of armor pads.

Conclusion

Finally, I would like to answer a frequently asked question regarding self-repair of the mechanism. So, repairing the lock cylinder at home is impossible. More precisely, you can repair, the key will turn, but the larva will begin to open even with a pin. So only replacement of the cylinder will help.

Repairing a larva at home is difficult, almost impossible.

If we talk about the device of a door lock, we can distinguish fundamental differences for its different types. Today, a wide variety of structures are being installed in apartments and houses that are able to protect the home from thieves and at the same time are convenient to use. In order to better familiarize yourself with the range of fittings for entrance and interior doors and their features in accordance with GOST, it is worth considering certain types of products in more detail.

Today there is a huge variety of door locks.

Types of castles

First of all, you should understand the classification of locks and their description according to GOST. There are several main criteria by which the differences between individual types of fittings are determined.

First of all, it is necessary to distinguish between locks for entrance and interior doors, their device may be similar in some respects, but in general they are completely different elements.

If we talk about installation methods, it is worth highlighting the following varieties:

• Overhead. These are the simplest models used for installation on front doors. They are attached directly to the canvas, usually they are not equipped with a handle. It will not be difficult to do such work with your own hands.
• Mortise. These include the predominant majority of modern locks for both the front and interior doors. A mortise lock according to GOST is embedded inside the canvas and can be connected to the handle.
• built-in. It is installed during the manufacture of the door leaf and is directly an integral part of it. This is ideal for a metal front door.

Types of door locks depending on the installation method

The structure of almost any door lock is based on the presence of the following elements:

• secret mechanism (larva);
• retractable crossbars;
• pen;
• fake tongue;
• patch panel.

Interior door locks are usually limited to a simple latch, with no secret mechanism. At the same time, the front door cannot be left without reliable locking fittings. All products are classified according to the level of secrecy and degree of reliability. Belonging to a particular class determines the number of available secret combinations. The more of them, the more difficult it is to crack the door with a master key. In addition, there is a separate category of burglar-resistant models. Some of them cannot be opened without a native key.

An example of the design of a pin-type cylinder lock

In order to delve deeper into this issue and make the right choice when buying, it is necessary to consider the types of larvae according to GOST in more detail.

Lock mechanism

So, what does the entrance door lock consist of? The main part is the larva, it is the very mechanism that ensures the blocking of the structure in the opening and prevents outsiders from entering the room.

There are the following models:

• cylinder;
• level;
• disk;
• crossbar;
• cross.

Door lock options depending on the lock mechanism

Cylinder. These are the most familiar products, the secret part of which is located in a part similar to a cylinder. The device of the so-called English lock is as follows: inside the larva there are pins that block the mechanism in the closed position. The key has notches that move these pins according to the scheme and allow you to turn the mechanism.

Level. These products are very reliable. The scheme of a lever door lock consists in the presence of levers inside the mechanism. The key looks like a so-called butterfly or soldier and, when turned, raises them to the level specified by the encoding.

Disk. This is not the most reliable option, but it can be used nonetheless. The key looks like a rod cut in half with several notches. Inside the lock, the discs are rotated with this key, forming a tunnel and freeing the mechanism.

Crossbar. The device of such a door lock is equipped with a latch on the reverse side. Today, such options are rarely used due to their unreliability. The essence of the device is the presence of two crossbars, which are pulled with a special key or latch.

Crusades. The weakest type, the key has a cruciform shape. The larva can be opened with a Phillips screwdriver or any other suitable object.

Mortise and built-in locks

According to GOST, one of the types of door lock designs is a mortise model. Such products are used almost everywhere. A feature of the mortise lock device is that its main part cuts into the door leaf. Only a turnkey well, a handle and a decorative panel that hides the attachment points come out.

A mortise lock is inserted according to GOST into the end of the leaf, and its counterpart has the form of a plate and crashes into the box opposite. According to this principle, the mortise system is installed on doors made of any material.

A more advanced version is a built-in lock. Unlike a mortise, it is laid inside the canvas during the production process and it just cannot be removed. Only crossbars come out through holes cut under their shape. A feature of such models is that the number of crossbars can be simply huge, and they are located not only on the side, but also on the bottom and top to completely block the door in the opening.

Built-in locks are usually used on entrance metal doors.

Overhead structures

A simpler design can be called an overhead type lock. Today they are used less and less. A feature of the overhead door lock device is that, according to GOST, it is attached to the canvas without additional recess. The system consists of two parts: the main part contains a larva and a latch on one side, the well goes out on the reverse side. The second part is the response panel where the crossbars go.

The counterpart is also a consignment note, so if you do the installation yourself, it should be conveniently placed on the frame strictly opposite the exit of the pins.

Laid-on model of the castle

Interior models

If you analyze the question of how the design of door locks is arranged, you should also consider interior models. The device of a standard interroom door lock can be distinguished into a separate category, since, unlike previous models, these products have a special design.

The scheme of such a door lock is combined with a handle. In this case, in addition to the latch, there is an exit to the handle, which sets the latch tongue in motion due to its connection with a rectangular swivel pin. Depending on the type of handle, such mechanisms are divided into three categories:

• rotary round;
• nobs;
• pressure.

Types of locks for interior doors

The device of the interior lock almost completely coincides with the mortise scheme, but here the exit under the handle often has more space. It is qualitatively impossible to make a lock on the door with your own hands without certain skills, but it will be useful for every owner to understand their device.

The lock- this is the part of the cylinder lock that moves the bolt, and on which the secrecy of the lock depends. Professionals call the larva the cylinder mechanism of secrecy (CMS). Our clients often ask the question: “How can I change the larva, and what do I need to know for this?” In this material, we will consider the main parameters of the CMS and consider some examples.

For the correct installation of the cylinder, it is necessary to know the following parameters: the length of the entire cylinder, and the distance from the edges of the cylinder to the center of the mounting screw. In the diagram, these are the distances "BUT" and "AT".

A cylinder in which both parts are equal in length is called equilateral.

If the lengths of the 2 parts are different, then such a cylinder is called versatile.

Its length is 90 mm. This size of a versatile larva is often found in the doors of the Italian company UNION, as well as in the doors of Chinese production Outpost, Master-Lock, etc.
The parts of the cylinder are separated, the so-called rotary cam. Its width is 10 mm. Cylinder displacement is measured from the center of the rotary cam. If the cylinder is chosen correctly in length, it should not protrude much beyond the door leaf, decorative lining or door fittings. If an armor plate is installed on the cylinder lock, then the length of the protruding part of the cylinder will depend on the type of armor plate being installed, the method of installation and on the specific door. There are no special requirements for the length of the inner part of the cylinder.