What is a lock and how in general does it work?

What is a lock, and how, in general, does it work? A lock is a mechanism used in concurrency control to guarantee the exclusive use of a data element to the transaction that owns the lock.

How do locks work?

When the right key slides into a pin-and-tumbler lock, the pointed teeth and notches on the blade of the key allow the spring-loaded pins to move up and down until they line up with a track called the shear line. When the pins align with the shear line, the cylinder can turn and the lock will open.

How does a lock on a door work?

When it's locked, the cylinder engages a series of spring-loaded pins which keep the cylinder from turning. When you insert a key, the uneven edge pushes the pins upward to fit the key's height in that location within the lock body. Essentially, it recognizes the correct key when the pins move into their proper places.

How did old locks work?

By the Middle Ages, some warded locks made by English craftsmen were quite intricate. They were designed with a set of obstructions, sometimes shaped as circular plates, which kept the lock mechanism secure. When a key with matching notches was inserted in the keyhole, it would unlock the bolt.

How do you key lock?

How does a medieval lock work?

To open the lock, the key is inserted in the keyhole on the top of the body and then drawn through the slit, which compresses the springs so that the shackle can be withdrawn. This design allows one or more ward pins to be attached on the end with the openings. The key bit has notches for them.

Who invented a lock?

The earliest patent for a double-acting pin tumbler lock was granted to American physician Abraham O. Stansbury in England in 1805, but the modern version, still in use today, was invented by American Linus Yale, Sr. in 1848.

Why are locks so important?

Fundamentally, the primary purpose of a lock is secure things and people. It is a two-way street. On the one hand, you want the peace of mind knowing that something (your home or business) has been safely secured.

How are locks made?

The internal mechanisms of locks are generally made of brass or die-cast zinc. The cam, which is the tongue that protrudes from the lock to secure it, is usually made of steel or stainless steel. The outer casing of a lock may be made of brass, chrome, steel, nickel or any other durable metal or alloy.

What are the parts of a lock?

How do locks and dams work?

At the point where bodies of water at different levels meet, a dam and lock system bridges the gap by creating a contained area that can individually raise or lower its own water level to step a boat up or down the waterway.

What is the oldest known lock?

Early history. The lock originated in the Near East; the oldest known example was found in the ruins of the palace of Khorsabad near Nineveh. Possibly 4,000 years old, it is of the type known as a pin tumbler or, from its widespread use in Egypt, an Egyptian lock.

What is the oldest key?

The first key was seen 6000 years ago the same time locks were discovered too. This was in ancient Babylon, Egypt. It was made of wood and the key looked like a brush. It was heavy and not very durable therefore not the best material it could have been made from.

What is the oldest lock in the world?

The oldest known lock was found by archaeologists in the Khorsabad palace ruins near Nineveh. The lock was estimated to be 4,000 years old. It was a forerunner to a pin tumbler type of lock, and a common Egyptian lock for the time.

How did medieval doors lock?

Doors usually used solid keys, and sometimes the lock permitted access from both sides of the door, so the same key could lock in or out. Doors in Norman castles typically had dead bolts, which had to be turned a full turn since the key was directly sliding the bolt.

Did people lock their doors in the Middle Ages?

Some Medieval treasuries and armouries had up to a dozen locks on the door! Read more about Medieval locks. With gallant knights away on Crusades for much of the first half of the second Millennium AD, it became traditional for the Lady of the House to keep the keys to important safes and storerooms.

How were castle doors locked?

Portcullises fortified the entrances to many medieval castles, securely closing off the castle during time of attack or siege. Every portcullis was mounted in vertical grooves in the walls of the castle and could be raised or lowered quickly by means of chains or ropes attached to an internal winch.

How do you lock a door with a key?

Slide the key into the deadbolt keyhole and turn it clockwise as far as it will go. If you turn the key far enough, the door should lock. To remove the key, turn it counter-clockwise back to the position at which you slid it in – but no further! Pull the key out of the keyhole.

How does a master key work?

Master key system is a system that allows two or more keys to open one lock. Master keys will be able to open multiple locks. The greater the difference between the master key and the change key, the more master wafers will be needed. The more master wafers, the more possible keys can open the lock.

How can one key open two locks?

Any key that can open two or more locks is considered a master key. Many master keys use pin and tumbler locks. For a master key to work, though, there must be something called master wafers inside the lock. When the master wafers line up, the key and lock can turn freely.

What is chain lock?

Chain locks are made up of a series of hardened steel links (usually inside a protective nylon sleeve) and a lock. The lock can be integrated into the chain, or it can be a separate padlock.

How do you remove a lock if you lost the key?

Examine the handle and trim on the interior side of the door. There may be a small pinhole holding the handle in place. Insert a straightened paper clip into this hole and apply pressure to release the interior handle. Insert the pin straight through the lock cylinder to reach the lock's release mechanism.