Door closer
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A door closer or door lifter causes a door to close automatically . Simple designs are based solely on gravity or spring force . Modern door closers also take on the function of a door damper .
To protect escape and rescue routes from the ingress of smoke, tight and self-closing doors and door closers approved for this purpose are often required. If the door should normally be open, a fire alarm system must ensure that it closes automatically in the event of a fire.
Spring-operated door closers are usually mounted externally on the door leaf or the door frame, but they can also be integrated invisibly in recesses.
Heavy door leaves as well as doors in facilities for children, old and sick people are increasingly being equipped with systems that close and open the door with a motor . These are not to be confused with the widespread devices that only release a locked door leaf and are also referred to as door openers .
With automatic locking systems and systems, doors and gates can also be opened and closed automatically with remote or central control. The terms are misleading, as locking systems also refer to door locks that are keyed alike and that enable several doors to be opened with the same key.
In most cases it is desirable that the door closer not only bring the door leaf up to the frame , but also develop enough force to allow the latch to latch into the strike plate of the door lock . In particular, door closers on external doors and internal doors that are regularly exposed to winds have to generate a considerable amount of torque . Since door leaves that close quickly due to wind and spring force pose a risk of injury, these door closers are usually equipped with a mechanism to dampen the movement.
history
In August 1887 Otto Boedecker from Cologne founded a special company for door closers, which was called Sonntag & Boedecker ; his partner was Hugo Sonntag from Berlin. The Cologne-based company exploited the idea of a door closer, an invention of the two company founders, worldwide. The first and classic brand was the "Imperator", which is still attached to doors in old buildings and is being repaired by the company that still resides at the founding address.
scope of application
Door locking systems can often be found in apartment buildings and buildings with public traffic. By automatically locking house entrance doors each time they are opened, they reduce the entry of unauthorized persons. In addition, they mostly prevent opened doors from being accelerated so much by strong wind or willfulness that people are endangered or damage to the door element, frame or neighboring components occurs. Compared to rigidly installed door stoppers , damped door closers significantly reduce the forces acting on the door leaf.
Smoke and fire protection doors must be equipped with approved locking systems. These doors are used to close defined fire compartments , primarily in hallways and stairwells. In the event of a fire, self-closing fire doors help limit the spread of fire and, in particular, smoke.
Types
The simplest and most robust designs cause the door leaf to be lifted when it is opened (so-called door lifter ), so that it then moves back to its original position by itself due to gravity. The upward movement of the door leaf is achieved by inclined running surfaces of the joints of the door hinges or by an inclined rod between a guide point on the door leaf and the door frame, which straightens up when the door is opened and lifts the door leaf on its hinges .
In garden gates and animal gates , it is common to move the axis of rotation of the lower hinge away from the door leaf and outwards. As a result, the gate moves upwards at an angle when it is opened and falls back when it is released. Alternatively, the complete door can be installed at a slight angle to the vertical.
The closing force of the gravity-operated systems corresponds to simple door closers operated by spring force. With both systems, it cannot always be ensured that the door reliably slams into the lock. In the case of light door leaves in particular, the effect of gravity in relation to the area of the door leaf is so small that the closing movement is inhibited by even slight air movements.
In order to prevent a gravity or spring-driven door leaf from slamming shut with force, separate soft-stop mechanisms are installed, which are known under the brand name Dictator . It is usually installed on the upper edge of the door leaf (on the side away from the door hinge). The soft stop catches a door that slams quickly and closes it slowly. It can also be installed in addition to an ordinary door closer if, for example, the latch of a warped door leaf does not reliably snap into place.
Some door closers offer the option of locking the door leaf in the fully open position, so that there is no need to use a separate door holder .
Muted door closers
With damped door closers, the energy required to close the door is stored in a spring when it is opened and released again in a hydraulically damped manner during the subsequent closing movement . The closing force can usually be adjusted continuously via the compression of the spring and the closing speed via valves.
In the case of door leaves that swing freely on both sides and do not have a stop on the frame, the aperiodic borderline case is aimed at, in order to close the door leaf in the shortest possible time without overshooting.
Damped door closers are mounted either on the edge of the door leaf or on the frame and connected to the other part via one or two arms. The coupling via two arms is also called a scissor linkage .
If only one arm is used, it either slides over a roller or a slider; alternatively, there is a roller or slide at the end of the arm and is guided in a slide rail. Guide rail are with cams and cam (Engl. Cam and) pinion technology available.
Special designs
If both leaves on double-leaf doors are to be closed by door closers, a linkage is often provided for the closing sequence control. This causes the first stationary wing , the active leaf is closed, so that the grooves of both wings on the face plate (impact of the two wings) mesh as designed. Otherwise there is a risk of the door rebates jamming into one another. Then they would block each other, and the entire double door would be blocked. The closing sequence control is defined in accordance with DIN EN 1158 and represents an optional automatic setting for double rebate doors with door closers. Depending on the system, there is a choice between mechanical and electrical closing sequence controls.
Large and prestigious doors, just like all-glass doors, are often equipped with a floor spring that is invisibly mounted in a recess in the floor and floor plate.
conditions
DIN 18040 for barrier-free construction defines a maximum opening moment of size 3 according to DIN EN 1154 for doors that require the use of a door closer. This is currently defined as 47 Nm (measured on the door closer) when opening between 0 ° and 60 ° .
DIN Spec 1104 is a technical specification that recommends an opening torque reduced by 40% for a door opening angle between 2 ° and 60 °. This should make it easier for children, the elderly and the disabled in public and private buildings to open the door and increase the ease of access.
When doors are to be kept open due to the building code requirements self-closing to be carried out, the door leaves can by electrical arrester be locked magnetic (electric). Alternatively, free swing door closers with a “freeswing” function are used. Once opened against the spring force, these release the door leaf and allow the door to be passed without additional effort. Here the door closer itself is locked in the pretensioned state. In the event of a fire, the pre-tension is released and the door closes automatically. Mechanisms for keeping fire protection doors open in everyday life are used in particular in hospitals, retirement homes and kindergartens to facilitate the use of the buildings.
Doors with requirements for fire or smoke protection must generally be equipped with approved door locking systems. A closing sequence control is required for double-leaf doors to ensure that the passive and active leaves are locked tightly. Hydraulic door closers for fire protection doors must meet the requirements of the DIN EN 1154 standard, door closers with electrical hold-open devices in addition to those of the DIN EN 1155 standard and door closers with closing sequence controls in addition to DIN EN 1158.
- Simple mechanical closers
A spring for closing a garden gate
Overhead door closer with link arm
Overhead door closer with slide rail
Door closer integrated in the door leaf
Floor spring
a simple door closer
Individual evidence
- ↑ Ingenious invention from the Belgian quarter - the "Imperator" closes every front door , broadcast in WDR from January 2, 2013
- ↑ Closing sequence control. In: BauWissenOnline. From architects and engineers. February 24, 2020, accessed February 24, 2020 .
- ↑ DIN German Institute for Standardization (publisher): DIN EN 1154 . Beuth Verlag, Berlin April 2003.
