Cable trays have been used in power stations and large industrial plants for a number of years to support cables as an alternative to placing them in conduit. Such cable trays are generally supported from the wall or ceiling, at levels above a person's head while standing, in order to avoid obstructing normal floor space. Such cable tray installations are shown in U.S. Pat. Nos. 3,137,468 and 4,232,845.
Distribution ducts for wires or cables, generally smaller in cross section than those on cable trays, have also been suggested. Again, the distribution ducts are normally mounted from the ceiling or wall at elevations so as not to interfere with a person standing on the floor, again to conserve floor space. Such ducts are often in sections, and can be assembled end-to-end to form wire way for cable duct. Examples of such ducts are shown in U.S. Pat. Nos. 2,917,083; 2,956,587; 3,003,794; 3,312,251; and 3,541,224.
In many multifloor buildings, a current practice is to utilize concrete floors. Electrical conductor distribution ducts have been provided inside the concrete of these floors for many years in order to provide electrical power distribution to the many locations within the building. Examples of such distribution ducts within the concrete floor are shown in U.S. Pat. No. 2,912,197; 3,061,663; 3,303,264; and 3,973,366.
In more recent years, computer rooms, data processing rooms, and electronic equipment rooms in general have been rooms wherein the overhead wiring approach has been minimized in favor of the distribution of wires and cables on top of the concrete subfloor and below a removable-panel, raised floor on which the electrical equipment is placed. This type of raised floor on a subfloor is shown in U.S. Pat. Nos. 3,324,614; 3,924,370; and 4,296,574. U.S. Pat. No. 3,316,680 shows a raised floor supported on floor joists which are also the cable distribution duct, and both carried by the same upright posts. U.S. Pat. No. 4,016,357 shows the typical installation of communication cables wandering in all directions and lying on the concrete subfloor.
Other solutions to the electrical interconnection problem have been suggested. For example, U.S. Pat. No. 3,943,414 shows a pallet approach with the electrical equipment resting on the top of the pallet and the cables passing through apertures in the girdered interior of the pallet. U.S. Pat. No. 4,255,611 shows the electrical connections made to junction boxes behind what might be considered a baseboard for walls of the room.
The space between the subfloor and the raised panel floor is of necessity rather restricted. There are a number of times when there is moisture on the floor, such as due to condensation.
Modular duct sections have been used under a raised floor, but resting on the floor, so that there was no space for cable or other conductors below such modular ducts, which were interconnected to form a continuous ductwork.
With the increased complexity of electronic equipment and the increased number of pieces of equipment with a single room, the interconnection of these by communication cables and power cables has become more complex. The cables on a concrete subfloor in a computer room have come to look like a mass of spaghetti. The cables have become so entangled that it is most difficult to pull out one particular cable from the mass on the floor should it need to be changed or rerouted for any reason.
USPTO Backgrounds
USPTO Backgrounds