How Does Door Closer Works? | 3D Animation | Hindi | 3D World

Описание: A door closer is defined as any mechanical device that closes a door in a controlled manner, preventing it from slamming, in general after someone opens it,[1] or after it was automatically opened. The force used to open the door is stored in some type of spring and when released this energy is then used to return the door to a closed position. Door closers can be linked to a building's fire alarm system. Where doors need to be held open for the majority of the time they are held back with an electromagnetic device.[2] When the fire alarm is triggered it cuts power to the electromagnetic hold-open device allowing the doors to close. These hold-open devices can be separate from the door closer or part of its design.[3]

Early history
This is a William Newman single action "Invincible" model.
Single action floor spring with pneumatic check. The brass decor plate and shoe are removed to show the internal workings.
Gravity alone may be considered to be the first "door closer". Before any mechanical devices were attached to doors to close them, the way in which the door was hung automatically closed the door once opened. This technique to hang doors may have originated with gates because of the need for them to remain closed once traffic has passed through. The method involves an intentional misalignment of the hooks or pintles that traditional strap hinges rest on, the bottom pintle protruding from the door post further than the top one. This configuration ensures the weight of the door and gravity will always close any gate or door opened. It is best used on doors only opening one way, many old church doors for instance can still be seen to be hung in this manner.[4]

One of the first references concerning a device to close a door can be found in the writings of Hero of Alexandria who describes his "automata" which controlled the doors of temples, both opening and closing them automatically.[5] Weights and levers have also been used to close doors,[6] Another device for smaller domestic doors used a loop of rope or skein fixed to the door frame, that was twisted, with a piece of wood placed in between the twists to push the door. The opening of the door twists the skein further, when the door is released the rope's torsional force pushes the arm back against the door, thereby closing it.[7][8]

In more modern times the clock manufacturers Thwaites and Reed in 1850 claimed to be the original inventors of the spiral door spring.[9] The earliest English patent for a door closing device consisting of weights and pulleys was issued in 1786 to Francis Moore[10] The first English patent issued that mentions a spring can be traced to a few years later to that of Henry Downer.[11] (Ironmonger) of Fleet Street, London recognised for the invention of a "spring to shut a door" (1790),[12] There were even earlier devices invented to close a door,[13] for instance, Mr Delevitz's model of a door with spiral spring hinges (1768)[14] Earlier still is reference by way of a letter between Sir Edward Filmer (3rd Bart.) and his brother, Beversham Filmer dated 1748, in which they discuss a door spring.[15] Whilst not a door closer, there was a mechanical statue, reported in the Stamford Gazette and displayed by a Monsieur Delanois at the White Swan in Stamford, December 21, 1736, that opened and closed his own door.[16][17][18]

Closer development
The first door closers consisted of just a spring mechanism only, as time went on the rate at which the door closed was arrested or checked by adding an additional checking device. Door closers at this time were known as a door spring and check. Later these two devices were combined into one unit that both closed the door and slowed the speed at which this was done. These early "door closers" used a pneumatic piston to check the speed, later models used a hydraulic or oil filled device for the same effect.

The first patent for a pneumatic device to prevent the sudden slamming of a door was given to William Bullock and James Boaz, on May 13, 1813 (Patent Number 3695).[19] An improved hydraulic device to prevent the "clapping" (slamming) of doors was patented by William Overden Snr and William Overden Jnr in 1864.[20] Door closers that utilize the properties of vulcanised Indian rubber have also been patented and used.

The use of door closers expanded during the Victorian era.[21] Companies such as William Tonks and Son, James Cartland and Sons and William Newman and Son and were all based in and around Birmingham.[22][23] receiving in 1974 an award for their one millionth door closer produced.[24] In 1907 the Briton B was first placed on the market.[25]

In the United States, Lewis. C. Norton started his business in 1877, entering the door closer market in 1880 with a door check for the Boston Trinity Church.[26] Eugene Blount, Francis Richards and Joseph Bardsley also played important parts in the development,