Door lock
Above: lifting latch (a)
Middle: locking spring (b) for bolt
Below: key house (c), night slider (d)
.JPG)
A door lock is a mechanical lock for doors ; it keeps the door in the frame and thus closed.
function
Locks are usually mechanical devices that can be locked with a key and usually opened with a door handle , rotary knob or handle bar (for emergency exits and escape doors). Swap locks can also be opened with the key alone.
In Europe, mortise locks are mainly used that are completely embedded in a recess in the door leaf . Trap and lock bolt are movably mounted in the lock and a drive during closing or when locking the door in recesses in either the strike plate are steel frames or directly in the frame . Instead, a protruding locking bolt was attached to the frame of historical doors on the room side , into which the latch and bolt latched (see historical door lock in the picture on the right).
When the door is open, the lock latch protrudes from the lock on the outer edge of the door leaf and is usually beveled on one side of mortise locks. If the door falls into the lock, the latch is pushed into the lock against spring pressure along its inclined surface and snaps back into the recess of the frame as soon as the door leaf is completely in contact with the frame. In the case of the box locks that were used in the past , the inclined surface of the latch instead moves along the locking bolt until it snaps back again.
By operating the lever handle (colloquially door knob or door handle called), the event draws back, and the door can be opened.
Today, interchangeable locks are mainly used, in which the latch can also be withdrawn using the key. This means that a fixed door knob can be attached to the outside of house and apartment doors instead of the door handle. In this case, the door cannot be opened from the outside even if it has just fallen into the lock and not been locked.
With a revolution (fachsprachlich: tour ) of a key, the bolt is slid into the provided recess of the frame. Locks in which the key can be turned completely more than twice are referred to as gear locks .
If you lose or forget the key to a court order and in " imminent danger " is often a key service or the fire brigade called to open the door with appropriate tools.
Terms
An essential component of the door lock is the follower or handle follower , a rotatable element with a square hole in the center to accommodate the door handle square (also handle pin , square pin or pin pin ).
To operate the latch and hold the door, a door handle is pushed onto the square pin on one or both sides of the door leaf . The door handle is also through the bolted to the door leaf door sign or smaller format Rosette out.
A door is locked by the latch if it can only be opened by pressing the handle. A door is locked , locked , locked or closed when it additionally by an unsprung, rigid lock bolt is secured in a matching recess of the frame engages.
In the case of a wooden frame, the latch and bolt usually grip into an additionally attached, resistant strike plate .
Crank latches are used in government locks for particularly quiet closing.
Panic door locks are often required in public buildings . In this case, when the handle or a panic bar is actuated, not only the latch but also the locking mechanism must snap back completely to prevent people from escaping in the event of panic.
safety
For exterior doors are usually profile cylinder locks - often with anti-drilling - used inside the building - depending on the application - also cylindrical or even (especially if there are no safety requirements exist) warded locks . In Europe, the Euro profile cylinder is installed in most households. In addition to this, the Swiss round cylinder and the UK oval cylinder are common. To protect against duplicate keys and lock picks for profile cylinder locks the upscale (price) class will be offered a variety of defense mechanisms, through to key safety gear. In Switzerland , round cylinders are mostly used instead of profile cylinders .
To protect against being pried open, more modern security locks push the bolt forward with a turn of the key at least 20 mm, which increases the resistance to being pushed open. Locks with increased security requirements are also available with a reinforced bolt (hardened or with integrated steel bolts).
To increase the security of burglar-resistant doors, several tumblers are often used in the form of a second latch, several bolts ( multi-point locking), extending hooks, locking claws or by using several similar door locks.
If the property is secured with a burglar alarm system , the door locks are often provided with a bolt switch contact to ensure that all doors are locked before the system is armed .
equipment
- an electric door opener , usually found on front doors of apartment buildings, or if there is otherwise a desire for remote opening - instead of the door latch, a locking tongue on the strike plate is moved electromechanically when released - and card locks that usually belong to locking systems in hotels.
- New building keys are universal tools for opening doors that do not have a door handle attached.
development
- At first, doors were locked with wooden bolts, which were placed or pushed into a recess in the frame and fixed to the door leaf by (iron) fittings.
- The first locks made of metal (mostly iron) were mainly attached to the inside of the doors or chests and the mechanics were often visible. They were often locked with very large and artistically decorated keys.
These box locks were widespread until the beginning of the 20th century and can be found in many old buildings (often in rural areas) up to the present day. - The company Julius Bauer in Heilbronn produced in 1910 the first self-closing door lock ( "safety lock") in the world.
- A more recent development are locks that are opened contactless with an RFID chip, usually in the form of a chip card. Security problems arise in the event of a faulty software implementation.
literature
- Fritz Nüssel (photos), Erich Pfeiffer-Belli (text): key and lock. Beauty, form and technology through the ages. Shown at the Heinrich Pankofer Collection, Munich . 4th edition. Callwey: Munich 1984, ISBN 3-7667-0702-7
- Friedrich Werner Schlegel: door lock and fitting. History, problems, constructions . Lange: Duisburg 1952
- Friedrich Werner Schlegel: Cultural history of the door locks . Lange: Duisburg 1963
Web links
Individual evidence
- ↑ Google: Security hole in the door locks of the company headquarters Report on Heise Security from September 4, 2018, accessed on September 4, 2018