Door Knob Lock

Door Knob Lock

Types of Locks
By Carmine Bailey - Ezinearticles

A lock(Lk) can be defined as a device to fasten an object, specifically a door, a drawer, or something of the like without a special key or combination. Locks are used to protect people and their property against theft and damage. They are many kinds of locks available in today's market and all of them require a key of some form to unlock them. Combination locks, time locks, chain locks and electronic locks do not require the traditional form of keys to unlock them, though the adage applied to these locks for simplicity sake.

All locks have some sort of bolt that is used as the locking mechanism. In door locks the bolt slides into a metal plate in the door frame. A key of some form or the other is required to operate the lock from the outside. A release of some form or the other, normally a latch or knob unlocks it from the inside. The bolts used in most in door locks are spring bolts or deadbolts. Spring bolts are more widely used now-a-days. They are more convenient to use as they do not require a key to be locked from the outside. They snap into the door frame when the door is closed and is held in place by a metal spring.

Deadbolts are the most secure type of bolt. Dead bolts are mounted into a steel frame on the inside surface of the door. Such deadbolts Lk with a key from the outside and by turning a small knob from the inside. Other deadbolts are set in the door. They are called 'dead' because they cannot be pried open. There are many types of Lks. The common types are - mortise Lk, rim Lk, cylindrical Lk, tubular Lk, combination Lks, padlocks and electronic Lks.

Mortise Lk have a locking mechanism mortised (cut) into the door. The doorknobs screw into the locking mechanism. Mortise locks have either spring bolts, deadbolts or both. A deadbolt measuring about one inch long provides maximum security. Mortise locks are extremely strong when installed in a sturdy door. Rim locks provide additional security to doors already equipped with one or more other locks. They have a bolt mechanism mounted into a frame on the inside surface of the door. Cylindrical locks are the type most commonly found on household doors. Cylindrical locks have a keyhole in the doorknob. Most cylindrical locks have a spring bolt.

Tubular Lk have a bolt - in most cases a deadbolt- that is enclosed in a tube attached to the locking mechanism. The deadbolt provides additional security for doors that also have a cylindrical lock. Combination locks have a movable dial with a series of numbers around it. To release the lock, a person must turn the dial left and right in a sequence of three or four numbers. The numbers, and the direction in which the dial was turned, make up the lock's combination. A combination lock has disk-shaped tumblers. Padlocks are portable locks that require either a key or a combination to be opened. People use padlocks to fasten two objects together or to help protect such objects as bicycles, lockers and trunks.

Door Knob Lock