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Modern manual door closer Eclipse door spring and separate checking mechanism. A door closer is a mechanical device that regulates the speed and action of a door’s swing. [1] Manual closers store the force used to open the door in some type of spring and reuse it to close the door. Automatic types use electricity to regulate door swing behavior.
The operator may or may not include a return spring to close the door in case of power failure while the door is open. Operators are often categorized by the means by which the motor's energy is applied. Electromechanical—the motor uses purely mechanical means to open the door: gears, cams, levers and such. This is the preferred type in the US.
This is an accepted version of this page This is the latest accepted revision, reviewed on 5 February 2025. Device to open or close door Various examples of door handles throughout history A door handle or doorknob is a handle used to open or close a door. Door handles can be found on all types of doors including: exterior doors of residential and commercial buildings, internal doors, cupboard ...
A crash bar (also known as a panic exit device, panic bar, or bump bar) [1] [2] is a type of door opening mechanism which allows users to open a door by pushing a bar. While originally conceived as a way to prevent crowd crushing in an emergency, crash bars are now used as the primary door opening mechanism in many commercial buildings.
An electromagnetic door holder (electromagnetic door holder and release or hold-open device, sometimes informally called a mag hold open or electric doorstop) is a simple electromechanical mechanism which can be used to hold a fire door or security door open until given a signal to release.
The operator is placed in the space above the sliding door. An electric motor, geared down to get a lower speed and a higher torque, drives a pulley at one end of a belt. The door is clamped to the belt. To open the door, the motor turns the pulley, which in turn turns the belt, which in turn drags the door. To close the door, the reverse occurs.
To prevent access to the inside of an electric kiln, a trapped key system may be used to interlock a disconnecting switch and the kiln door. While the switch is turned on, the key is held by the interlock attached to the disconnecting switch. To open the kiln door, the switch is first opened, which releases the key.
Fail-safe locking devices are unlocked when de-energized. Direct pull electromagnetic locks are inherently fail-safe. Typically the electromagnet portion of the lock is attached to the door frame and a mating armature plate is attached to the door. The two components are in contact when the door is closed.