Doorknob
From Free net encyclopedia
- For the game, see doorknob (game).
Image:DoorknobGold.Stock.xchng.jpg Image:Center Knob.jpg A doorknob is a popular type of handle used for opening and closing a door. In its simplest form, a doorknob provides only a place to grab so that the door may be pulled toward oneself. On most modern doors, however, doorknobs can be turned to operate a latching mechanism, which normally holds the door closed. A doorknob may also have a lock built in, though in some cases it is beneficial for the lock to be separate.
Doorknobs can be difficult for the young and elderly to operate. If a person lacks a firm grip a doorknob must sometimes be operated using two hands. For this reason doors in most commercial and industrial buildings and in many households now use an operating lever, rather than a doorknob, as the lever does not require a firm grip. Levers are also beneficial on doors with narrow stile widths where the reduced backset leaves insufficient space to comfortably turn a doorknob.
Most household doorknobs use a simple mechanism with a screw-style axle (called a spindle) that has at least one flat side, which is passed through the door latch, leaving some length exposed on each side of the door to which the knobs are attached. Knobs are attached on both sides by screwing them directly onto the spindle, and then securing one or more retaining screws (set screws) through the knob perpendicular to the flat of the spindle. Doorknobs that lose traction can frequently be repaired by replacing or adjusting the set screw, which prevents them from slipping on the spindle.
The location of the doorknob on the door may vary between a few centimeters away from the edge of the door to the exact center of the door, depending on local culture, decorative style or owner preference. The distance from the edge of the door to the center of the doorknob is called the backset.
Doorknobs in popular culture
In the TV series Bewitched, Aunt Clara had a very impressive collection of doorknobs. She referred to an unusual glass doorknob in her collection as the doorknob equivalent of the Hope Diamond.