How door locks work
This iron metalwork object is a 16th century rim lock and key from France. |
Contents |
[edit] Introduction
A door lock is a mechanism used for security purposes - preventing a door from being opened by unauthorised people. There are many different types of door locks. Two of the most basic types of locks are rim locks and cylinder locks.
[edit] Rim locks
One of the oldest types of locks, the rim lock uses a bolt and key to secure the door. The bolt in the lock is moved when the correct key is inserted into the mechanism and turned. This action presses the tumbler - which is kept in place by a spring - up, and frees the bolt.
Next, the key bit engages with the corresponding notch under the bolt. Turning the key moves the bolt until the catch of the tumbler fits into next notch on the top of the bolt.
In simple locks, this completes the locking action. Greater safety is provided by a lock having not one, but several tumblers.
[edit] Cylinder locks
A cylinder lock uses a rotating mounted plug. When locked, the cylinder is held in place by several pin tumblers that have been moved into the proper position by springs. This allows the pins to fit into corresponding holes in the cylinder and keep the cylinder from moving.
A key is then inserted into the lock, which raises the pins so their tops move to a position that corresponds to the top of the outer surface of the cylinder. When the different segments of the tumbler are not connected, the cylinder can move freely when the key is turned. This allows the bolt to move and unlocks the door.
Another type of cylinder lock is the disc tumbler lock. This type of lock uses movable discs instead of pins to lock the cylinder.
[edit] Related articles on Designing Buildings Wiki
Featured articles and news
Download your free guide.
Four new types of prior approval for solar developments
Online Planning Portal application types from 5 September.
Election fails to spark construction industry revival
Contract awards and planning; post election.
Making diversity and inclusion easy for SMEs
The CIOB tool for companies with limited resources.
Sustainable Futures: Redefining Retrofit for Net Zero Living
BSRIA Briefing 2024, initial speakers announced.
Looking back at the UK's first Passivhaus leisure centre
Reflections on St Sidwell’s Point with CIAT.
A-Level results and electrical apprenticeships
Electrical Skills Index highlights areas with skills shortages.
One of the world's more unusual drive-throughs.
A quick introduction.
Hadrian's Wall Path and the national trails
The trails are heritage assets in their own right.
Articles on timely advice and hydraulic lime.
Building Designers Association of Australia
CIAT and BDAA sign Memorandum of Understanding.
Built Environment Inclusive partners issue statement committed to inclusion.
Building regulation requirements can have unintended consequences.
CIOB announces 2024/25 vice president
Sustainability champion Professor Saul Humphrey.
Accelerating towards a net-zero built environment.