doors
1. Door is a screen usually of wood, metal, glass or a combination of materials to close an opening to a room or building..2. The function of a door is to provide passage in and out of a room or building. Doorway is the entrance (including a door frame) usually constructed of masonry, wood or metal and consisting of jambs, and an arch. It often includes panels of glass or other materials; sometimes it is surrounded by architectural or sculptural elements. The History of Door Development The first doors were simply hides or textiles. In ancient Egypt people used doorways with matting that could be rolled up and lowered. The Greeks and Romans used stone doors on tombs; they also used bronze doors which were monumental and looked beautiful. The Romans made solid doors, which were double doors, that is, consisted of two leaves, each was hung at one side of the doorway closing together without a mullion. a) Wooden Doors The wooden door was the first type used in old times. The doors in the houses of Greeks and Romans looked like modern wood- paneled doors. They were constructed of stiles and rails (vertical and horizontal members) framed together to support panels and equipped with locks, keys and sometimes hinges. The doors of the classical times were of a wood-framed paneled type richly carved, mostly they were double doors. The traditional types of wooden door came from the middle ages and the Renaissance. At that time the door was constructed of vertical Planks backed with horizontals (ledges) on the inside or with diagonal braces. The rising production of glass in The 19-th century made it possible to produce doors with one large panel of plate glass. The perfection of safety glass helped to produce the door of a solid Glass slab l/2 on 3/4 in. thick. The wood frame supporting large glass panels was mostly replaced in commercial and public buildings by the frames of metal: bronze, stainless steel, aluminum. b) Modern Doors From The 19-th century there has been a great technical development in the door construction:
1) the appearance of automatic door closers and openers — hydraulically, pneumatically, or electrically activated;
2) The innovation in hanging doors; new types were introduced: revolving, folding, sliding, and rolling. The revolving door consists of four valves (glass) mounted at right angles and revolving about central pivot in a circular vestibule, thus forming a constant air lock. The folding door is a series of wooden leaves hinged together to fold to one side of the opening. The sliding door (wood paneled) is carried by rollers on a metal track disappearing in the wall. Large wooden sliding doors are used in barns, and, in factories; the metal-frame type has been much used in large structures (aircraft hangar doors 75 ft. wide and 46 ft. high). The rolling door constructed of tubular astragals (fragments) of aluminum or steel (galvanized or stainless) rolling up on an overhead track is usual for industrial installations.
