GB2260034A - Underfloor cable distribution system - Google Patents

Abstract

An underfloor cable distribution system comprises a plurality of outlets 22 set in the floor and guides 12 for the cables under the floor. The guides may be channels or tubes set in a solid floor (Fig 15), rigid or flexible tubes located below a suspended floor (Figs 2 & 5), or a rail or track having a carriage (Fig 10) below a suspended floor. A pull through 26 may be associated with each tube or carriage, the pull through having a device 28 to receive the cable to be located in the tube. The device may be hollow to protect a plug or socket secured to the cable, see Figures 8 to 14, as it is drawn to or withdrawn from an outlet. A distribution centre 10 may have satellite outlets 22 or a main services duct (212, Figure 15) with outlets (234) on each side. The centre and outlets may be colour coded. <IMAGE>

Description

Title: Improvements relating to underfloor distribution of trunking systems Field of invention This invention concerns underfloor distribution systems and trunking systems by which electrical power and communication cables and the like can be made available to work stations such as desks and benches in offices and laboratories, particularly large open plan areas where flexiblity of layout is a prime consideration.

Background to the invention Various attempts have been made to provide flexible under floor distribution systems for conveying power and communication lines such as telephone and computer links to work stations. Thus wall mounted trunking both at floor level and desk height have been tried. Such an arrangement is acceptable if the desks or work stations are all to be located adjacent the walls but does not solve the problem of island work stations in large open plan offices.

Dropping conduit and cabling from ceiling height is unsightly and has never been acceptable.

Underfloor ducting with outlets at regular intervals over the area of the floor has proved a popular solution particularly with carpet tiling. However if flexibility of layout is to be provided, considerable redundancy of underfloor hardware is necessary. This has tended to make the installation of such flexible systems expensive.

It has also been proposed to combine a distribution box with fixed ducting by attaching the dislribution box to the ducting by a relatively long flexible cable or umbilical cord through which power and communcation cables can pass and to provide for the box to be relocatable within the floor in an area centred on the point from which the cabling exits from the ducting. This type of arrangement is of particular application where suspended flooring is used and is itself constructed in the form of a grid of square panels each of which is covered with carpet and into selected ones of which distribution boxes can be set with a lid, which if necessary can be itself covered with carpet to hide the fact that the box is there.Such a system offers considerable flexibility in that floor panels containing a box can be interchanged with blank panels within the capabilities of the umbilical cord feeding the box attached to the panel. However in practice the cost of relocating such flooring panels has proved to be very high and the full flexibility of such systems has not in practice been realised due to the cost of relocating panels.

It is therefore an object of the preset invention to provide a simpler underfloor distribution systems which do not require skilled labour to relocate cabling to different positions under the floor ana reduce the overhead cost of redundant hardware.

It is also an object of the present invention to provide alternative and simple systems for prox,-iding ducted cabling to cable outlets.

Summary of the invention According to one aspect of the present invention an underfloor distribution system by which power, voice or data cables can be supplied to any one of a plurality of positions in a floor, comprises: a. an underfloor distribution centre, b. a plurality of cable guides communicating below the level of the floor between the distribution centre and a corresponding plurality of outlet apertures in the floor, c. at least one set of cables extending along one of the cable guides from the distribution centre for supplying a work station located adjacent the outlet, and d. means by which the said cable set can be drawn along the said one guide either (i) into the central distribution centre (after disconnection from the workstation) for feeding subsequently along another one of said guides to exit from another outlet for connection to another work station located adjacent the said other outlet, or (ii) from the distribution centre to the outlet.

Each guide may be formed as a channel or tunnel in a solid floor.

Alternatively where supported flooring is employed, the guides may comprise tubes of plastics or metal and may be of any appropriate cross-section but typically of circular cross-section.

Where discrete tubes are employed, the tubes may be rigid, semi-rigid or more preferably flexible.

Preferably each outlet socket which communicates with the guides includes an openable or removable cover which normally closes off the exit but can be opened or removed to permit =he satellite cabling to pass to an adjoining work station.

Convenienty a pull through or draw wire or cord is associated with each guide so that the free end of a satellite cable set can be attached to the wire or cord and pulled through the relevant passage from the distributimn centre to the chosen floor outlet. By leaving the cord or wire in place the same mechanism can be used to withdraw the satellite cable set from the tube back into the distribution centre in the event that disconnect on and further change is to be made.

Typically rlugs or sockets are provided at the free end of each satellite cable set for attachment to complementary sockets or plugs associated with the work station. In order to prevent damage occuring to such sockets etc, a housing mal,- be provided into which the sockets can be fitted whist the cable set is to be drawn in either direction long a guide.

The housing may be attached to the draw wire or cord where provided Sc that it is a permanent fixture associated with the guide. Since this will mean a separate housing for each guide whether or not it is used for a satellite cable set, the resulting redundancy can be overcome by making the housing a detachable device which is securable at will to any one of the draw wires or cords but normally will remain within the distribution centre ready for use.

Although any number of guides can be arranged to communicate with the one distribution centre, typically the number is limited to perhaps six or eight.

Likewise although the guides can radiate in any direction from a distribution centre, it may be desirable to arrange that all the guides from each distribution centre extend in one direction or over one quadrant or half-circle centered on its distribution centre so that it will always be clear once the floor is in place, as to which distribution centre communicates with which outlets at floor level.

According to a preferred feature of the invention, this problem can alternatively be overcome by colour coding or otherwise marking the outlets and the distribution centres so that for example a coloured tag or patch is provided inside a distribution centre and all of the outlet apertures associated with that distribution centre are provided with a similarly coloured device either integral with the outlet or the passage means or both. Thus for example differently coloured flanges may be provided defining the outlets in the floor or differently coloured guides may be provided the colour of which is clearly visible through the aperture in the floor through which the cables are to extend. Thus for example a distribution centre having a yellow coding might well have all yellow guides or all yellow flanges defining outlets associated therewith or both.

Typically each outset is in the form of a flanged sleeve, the flange overlying the topside of the floor, the sleeve extending through n appropriately dimensioned aperture in the flooring material and being secured on its underside to the free end of the guide by which it communicates with its distribution centre.

The distribution centre is conveniently in the form of a metal tray the topside of which is open with a flange surrounding and extending outwardly from the opening in the topside of the box. The peripheral flange can be secured to the underside of floor panels in the case of a suspended floor and an appropriately dimensioned floor panel used to cove over the opening of the distribution centre box and complete the floor when wiring has been completed. By providing lifting means in each such panel overlying a distri'oution centre, so access to the cabling can be gained by simply lifting the appropriate flooring panel.

Where the floor panels are themselves supported on pedestals, the flange around the distribution centre box may conveniently be trapped between the upper end of two or more pedestals snd the flooring members located over the pedestals. In this way, total flexibility is possible if the underfloor iistribution centre is itself connected to ducting containing the master cabling via its own umbilical feeder since the distribution centre itself can be moved should a more major reshuffle be necessary, by simply removing the flooring panels above and around the distribution centre, lifting the box off the pedestals on which it is carrieS and relocating it on top of other pedestals and simply relocating the flooring members as appropriate around and over the box in its new position.

Where a suspended floor is made up from a matrix of square floor panels each of which can be lifted independently of the others, and in which the underfloor distribution system includes flexible guides for example of plastics material which communicate between the distribution centre and each of a plurality of outlets each of which is located in one of the flooring panels, further flexibility is possible by positioning each said outlet near one corner of its flooring panel so that the outlet can be positioned relative to the overall floor at any one of the corners of its panel by simply lifting the panel and rotating it until the outlet is in the desired corner position and relocating the panel in the floor.The only requirement of such an arrangement is that the flexible guides are sufficiently long in each case to extend to the furthest possible position of the outlet depending on the orientation of its flooring panel.

Where it is desirable that the flexible guides are suspended immediately below the flooring in the case of a suspended floor rather than resting on for example a concrete screed below the floor, support means must be provided.

Where the guides are tubing feet may be attached to the tubing for example by simply clipping to the tubing so that the latter are held off the screed.

Alternatively hooks or brackets may be attached to the underside of floor panels in alignment with the tubing runs to support the tubing below the floor well clear of the screed.

In another arrangement cords or wires may be stretched between upstanding floor supports such as pedestals and t tubing may be attached to or rest on the cables or wires so stretched. In one such arrangement the wires may be of elastic material and since the floor supports tend to be arranged on a regular pattern can be of a standard length adapted to be readily secured around supporting pedestals and stretched taught therebetween.

If it is desired to maintain such elastic material at a given eight, tubes or relatively rigid material may be slipped over the pedestals with apertures therein to which the elastic cord or wire can be attached at the correct height. Alternatively and preferably sheet material having apertures of the correct height can be wrapped around each pedestal so that the apertures align and the ends of the elastic material can be fitted through the apertures and secured in place again at the right height.

Means for supporting the tubing relative to such stretched material may also be in the form of sheet material having two relatively large apertures which when the sheet is folded over can be aligned and threaded over a tube and the elastic cord or wire can be passed through the loop of material to thereby support the tube below the stretched material.

In order to reduce the cost of the installation to the minimum, low cost flimsy plastics material may be used for the tubing and in that event it is important that the pul'ing through of the cabling does not damage the relatively flimsy tube wall. To this end the end of a satellite cable set particularly where the latter carries sockets or plugs is preferably encased within a generally smooth container which is itself adapted to be pulled readily through the tubing as by means of a pull cord or the like.

A preferred shape for the container is spherical and a simple spherical ball may be formed by two hemispherical shells adapted to be clipped together to form a sphere with the cable ends and plugs and sockets etc trapped within. The two hemispherical shells may be held together simply by frictional engagement, by a fir tree clipping arrangement or by means of a rubber band or the like which may conveniently be located within a circumferential recess in the outer surface of the two shells which is formed when the two shell halves are joined, and into which recess the band can slip.

According to another aspect of the invention the guides may not be solid walled and may in fact simply be defined by a guide or rail along which a carriage member such as a sledge can be pulled using an appropriate pull cord to thereby pull along the line of the guide a length of satellite cabling.Where the guides emanate from a central distribution centre, satellite cabling can be pulled from the latter to each of a number of desired outlets by attaching the free end of the satellite cable to a carriage means which is at the distribution centre end of the guide (track or rail) and the carriage means can be pulled by its appropriate pull cord to the far end of the guide (track or rail) using the pull cord so that the free end of the satellite cable set can be retrieved through an outlet associated with the remote end of the guide (track or rail) and after being detached from the carriage means can be pulled through the outlet for connection to a satellite work station.Since the carriage means remain at the outboard end of the guide (track or rail) the same carriage means can be used for retrieving the satellite cable set by reversing the procedure and pulling the cable set back into the distribution centre when it is desired that it should be relocated by detaching it from its carriage member when retrieved and attaching the free end of the satellite cable set to a further carriage means associated with another guide (track or rail) and repeating the procedure using the appropriate pull cord to feed the satellite cable set to the new selected outlet.

The guide (track or rail) may for example be in the form of a curtain rail extrusion and the carriage means may be similar to the sliders associated with curtain railing.

Where such track is employed, it may be suspended below the floor panels but is most conveniently not attached to the floor panels themselves but is suspended between pedestal supports or other underfloor support structure by means or cords or wires stretched therebetween.

According to a still further aspect of the invention, the passage means may be dispensed with almost completely if a series of pull throughs are provided between underfloor boxes, each pull through having associated therewith a container into which the socket or plug bearing ends of the satellite cable set can be stowed during pull through.

A container in the shape of a rugby ball or a box having roller means around its periphery may be employed.

According to a still further aspect of the invention, the number of flexible tubes left in situ can be reduced by employing a length of flexible tube for each outlet which is to be serviced, togehter with means for attaching a pull through cord to one end of the tube to allow the latter to be fed from a distribution centre box using the pull cord to the appropriate one of a number of different outlets in the floor and having positioned the tube, thereafter pulling through the tube the desired satellite cabling.

In such an arrangement only pull cords need to be left in position between each outlet and the distribution centre, the pull cords being used to guide and pull through the flexible tube in the manner described. Conveniently each tube has built within it its own internal pull cord whereby the satellite cable set can be pulled through the tube once the latter has been put in position.

It will be seen that the tube can be used again and again if desired in the same way as the satellite cable set thereby further reducing the redundant hardware below the floor.

It is to be noted however that these various alternatives are only available to suspended flooring in which a good cavity exists below the flooring panels and an underfloor screed or the like and are not in general suitable to solid floors in which fixed passages, channels, grooves or the like are provided through which the satellite cable sets can be pulled as required.

According to a further aspect of the present invention, in an underfloor cable distribution system a single main services duct is arranged to run t'nrough or below the flooring and at intervals therealong hollow tubes communicate with the interior of the duct and extend below or through the floor to terminate in cable outlets in the floor, through which cabling can extend from a junction box within the central duct to sockets either at floor level or ounted on furniture or apparatus or walls above the floor.

According to a preferred feature of the invention, pull through means is provided for use with some or all of the ducts to enable cables to be pulled through the tubes either from the central duct to the flooring outlets or from the atter into the central duct to enable electrical connections to be made between cabling in the central duct and the sockets or apparatus associated with the cable outlets.

Each of the outlets may be provided with a removable cap or cover and the pull through means may be associated therewith.

In a preferred arrangement the central duct is in the form of a shallow metal tray the top surface of which is covered b.- a plurality of removable plates typically of metal, an the duct is arranged centrally along the area which is =o be served by the cabling before the final floor screed is laid.Lengths of tubing are connected at one end to the side walls of the duct in registry with openings therein to communicate with the interior thereof, and at their other end to angled tubular fittings which are adapted to rest on the rough screed with their open ends pointing upwards, so as to occupy substantially the same plane above the rough screed as does the upper surface o the duct, and the final screed forming the floor is then poured or otherwise formed on either side of the central duct and over and around the tubes and around the angled outlets so that when the floor is finished, only the top surface of the duct and the upwardly directed openings of the angled tubular outlets are visible. The final flooring screed is thus finished to a height which is compatible with the height of the covered duct and likewise the outlets.

In an alternative arrangement the duct is located on a screed which itself provides a base for a framework on which a floor is carried. The tubes connecting the duct to the various outlets thus not only run in a generally horizontal plane but also in an upward manner to the outlets which themselves are fitted into apertures in the supported flooring markers.

According to another aspect of the invention, the tubes extending from opposite sides of the duct can be replaced by channels in a concrete or other solid screed the thickness of which is commensurate with the height of the duct and a rigid floor covering of wood or metal or plastics material covers the duct and the channels in the screed.

The floor may itself provide the cover for the duct or may overlay plates typically of metal which themselves cover the duct.

The outlets for the ducts in this arrangement are conveniently formed in the flooring panels and may simply comprise holes in the panels which register with the ends of the channels in the screed below the flooring panels.

Flanged sleeves with covers may be provided in the flooring panels to define the outlets and provide a neat trim thereto for decorative purposes.

The invention will now be described by way of example, with reference to the accompanying drawings, in which: Figure 1 illustrates somewhat diagrammatically one embodiment of the invention; Figure 2 illustrates in more detail how a distribution centre such as shown in Figure 1 can be mounted under a suspended floor; Figure 3 is a plan view to a small scale showing a distribution centre and various tubular passages feeding satellite cabling to flooring outlets in satellite floor panels; Figure 4 illustrates a modified satellite floor panel to the type shown in Figure 3 introducing further flexibility of layout; Figure 5 illustrates how a flimsy film tube can be supported between underfloor pedestals; Figure 6 shows to a larger scale how the ends of the elastic cord can be formed for securing to pedestal engaging sleeves;; Figure 7 shows an alternative arrangement in which the elasticity is obtained by spring; Figure 8 illustrates a ball type pull through for protecting plugs and so on; Figure 9 is an enlarged view of the ball shown in Figure 8; Figure 10 illustrates an alternative passage defining track; Figures 11 to 13 illustrate free pull throughs; Figure 14 illustrates a further embodiment in which the passage defining tubes can themselves be pulled through from a second distribution centre as required, and Figure 15 is a perspective view of one embodiment of the said further aspect of the invention partly cut away to reveal hidden detail.

Figure 1 illustrates a centrally located central distribution centre generally designated 10 from which twelve flexible tubes extend in a variety of directions one of which is denoted by reference numeral 12. Each tube communicates the an opening such as that denoted by reference numeral 14 in the wall of the square shallow box 16 within which the distribution centre is located. The box includes an outwardly directed flange 18 by which it can be secured to the underside of a floor or sandwiched between pedestals and flooring as will be shown in later drawings.

At the outboard end of each tube is fitted an outlet comprising a sleeve 20 having a radial flange 22. The outlet is secured in a generally circular hole in the flooring and the tube 12 is secured to the flange so that above floor level only the flange 22 is visible.

A bung shown at 24 may be fitted to any outlet through which a satellite cable set does not extend.

Along the length of each of the tubes is threaded a pull through or draw wire generally designated 26. Attached to the draw wire is a plug carrier which may be a simple piece of bent metal or plastics material as denoted by 28 or a more complex housing as will be described later.

In use a socket or plug or other array of electrical fittings attached to the outboard end of a satellite cable set is located within and attached to the plug carrier 28 so that when the satellite cable set is pulled through the tube either from the box 16 towards the outlet end and the flange 22 or in the reverse direction, neither the tube nor the electrical fittings are damaged in transit.

Multiway sockets with associated plugs (not shown in detail) are located within the box 16 and are denoted by reference numeral 30. The inboard end of each satellite cable is connected as appropriate to the sockets 30 so that the power, data and voice communication cables link into the master power, voice and data cables (not shown).

Figure 2 shows part of the arrangement of Figure 1 in more detail and illustrates how the central distribution unit and the outlet are fitted relative to the floor. In this case a raised floor is shown made up of square flooring panels 32, 34, 36 and these are supported relative to a screed 38 by means of pedestals 40, 42 etc. Each pedestal includes a flange at its upper end 44, 46 respectively on which the corners of four floor panels meet so that each floor panel is supported by four pedestals, one at each corner. Where a central distribution unit 10 is to be located beneath a flooring panel, the distribution centre is put in position before the surrounding and overlying panels are located in position and with the flange 18 overlaying the four pedestals defining the position to be occupied by the floor panel 36 which doubles up as the lid for the distribution centre.With the latter in position, the floor panels can be put in position and the flange 18 is trapped between the undersides of the flooring panels such as 32 and 36 and the flange 46 at the upper end of each of the pedestals 42 on which it sits.

Each of the floor panels may have carpet fitted to its upper surface as shown at 48.

In use one or more cables shown in dotted outline in Figure 2 and denoted by reference numeral 50 are threaded through the flexible tube 12 from the underfloor distribution unit where they are connected to the appropriate master cable for power, data and voice communications etc as appropriate. The free end of the cables 50 is connected by means of appropriate sockets and plugs either directly to appliances or to further sockets or the like to enable power, communications, data etc to be transferred to or from a work station situated close to the outlet generally designated 52 and formed by the flanged sleeve 20.

For electrical installation purposes, the underside of the floor panel serving as a lid for the underfloor distribution unit may be metallised or otherwise formed with a conductive screed or sheet.

The system envisaged by the invention is essentially a series of extension leads led through under floor passages typically in the form of flexible tubes extending from a central distribution unit 10 to satellites located distant from the central unit 10 to thereby provide data, power and communication links between work stations (not shown) located at the satellites and cabling communicating with the central distribution unit 10. It will be seen that flexibility is possible even within the layout shown in Figure 3 in that provided the flexible tubes such as 12 communicating between the central distribution unit 10 and the satellites such as 52, are long enough, the flooring panel to which they are attached at their outboard end can be moved to an adjoining position and the floor panel whose position it now occupies can simply be put in place of the one that has been moved.However the intention of the invention is to obviate the need to lift floor panels at all wherever possible and to provide sufficient outlets in a plurality of floor panels surrounding the central distribution unit with passage means communicating between the central unit and each satellite position through which cabling can be fed as and when required to serve work stations located adjoining each satellite outlet 52.

A degree of flexibility can be introduced into the system without the need to move more than one floor panel by adopting the arrangement shown in Figure 4. Here the outlet 52 is located adjoining one corner of the floor panel to which the tube 12 leads and by simply lifting the panel and rotating it either through 900, 1800 or 2700 so the position of the outlet 52 relative to the remainder of the floor can be moved to the position shown in dotted outline at 52A, 52B and 52C. It will be seen that this adjustment can be made without interfering with any cabling already threaded through the tube leading to the outlet 52 but only provides a relatively limited degree of movement and thereby adjustment of the position of the outlet relative to the whole of the floor.

Figure 5 illustrates how a relatively flimsy walled tube 54 can be supported from an elastic cord 56 between a pair of pedestals 58 and 60. An apertured flap 62 folded over the cord 56 joins the tube 54 to the cord and supports the tube clear of the screed 38 on which the pedestals 58 and 60 sit.

The height of the cord can be controlled by either grooves in the pedestals or as shown by means of flaps of plastics or fabric material 64 and 66 wrapped around each pedestal as shown with apertures at their upper corners to which the cord is attached.

For simplicity a cord can be attached as shown in Fiqure 6 using a pair or toggles one of which is shown at 68, the two being located at opposite ends of the cord 56 and held in place by knots or crimps 70 at opposite ends of the cord. The toggles can be inserted through the aligned holes 72 and 74 in the upper corners of the plastics sheet 64 (and 66 although not shown in Figure 6) and by twisting the toggle so the cord and toggle can hold the two corners of the sheet 64 together and since the latter is semirigid, the cord is supported at a specific distance above the bottom of the pedestals.

Figure 7 shows an alternative arrangement in which the elastic cord is replaced by an nylon filament which is relatively inextensible and a spring such as 76 is located at one end of the cord to introduce the necessary elasticity. In all other regards the arrangement shown in Figure 7 is similar to that shown in Figures 5 and 6.

Figure 8 and Figure 9 show how a ball shaped connector housing can be fitted to the end of a satellite cable set for pulling through a flexible tube. Thus in Figure 8 the tube is denoted by reference numeral 78 the satellite cable by reference numeral 80 and a hollow spherical ball 82 is shown attached to a continuous pull through cord 84.

The connectors located at the end of the cable arrangement 80 (not visible) are contained wholly within the hollow interior of the ball 82 and are thereby protected from damage and also prevented from damaging the wall of the tube as the cable assembly 80 is pulled through the tube.

The plastics film forming the tube may be non self supporting so that the tube actually collapses except when the ball is pulled through. The invention is not limited to rigid wall or semi-rigid wall tubes such as are shown in Figures 1 and 2. In this connection the film tube support 62 shown in Figure 5 and 7 provides wall support for maintaining the otherwise flimsy tube cross-section generally circular.

Similar supports are shown at the extreme ends of the tube shown in Figure 8 in the form of locating rings 86 and 88 for attaching the tube to the satellite outlet and the central distribution box.

The ball arrangement is shown in greater detail in Figure 9. This is formed from two hollow hemi-spherical shells 90 and 92 which are secured together by means of a rubber band or belt 96 itself located within the lined pair of grooves 98 and 100 formed in the two opposite shells 90 and 92. A pull through cord 80 is secured to a nose 94 and although not shown the opposite end of the cord 84 is secured to a similar nose at the rear of the ball as viewed in Figure 9. The satellite cable lead assembly 80 passes into the interior of the ball through an oversize opening 102.

The large connectors such as sockets plugs etc at the end of the cables are entrapped in the two halves of the ball by first of all opening the ball by removing the rubber band 96, placing the connectors in one half and reforming the ball by fittina the other closure half to form the sphere and refitting the rubber band 96.

Figure 10 illustrates an alternative arrangement in which the satellite cable 104 is connected to an outlet housing 106 which is secured by means of a clip 108 to the underside of a slider 110 which is received in the hollow interior 112 of a grooved rail 114 which extends below the floor level and may for example be formed from a plastics extrusion and held in place by means of stretched cords or rubber plastics or wire such as 116. The cords or wires etc 116 may be stretched between pedestals in the same way as the elastic cord 56 is stretched in Figure 5.

In use the cable 104 is pulled along the track by means of an endless pull cord 118 opposite ends of which are attached to respective opposite ends of the slider 110.

The junction between one end of the pull cord and one end of the slider is shown at 120.

Guides such as the rail 114 are not essential and an alternative arrangement is shown in Figure 11 in which a pull through cord 122 is attached at one end to an under-loor distribution centre 124 and at the other end to an enclosure 126 within which electrical connectors are housed. Another pull through 128 is connected to the other end of the enclosure 126 and terminates in another underfloor box 130 located at a position where a satellite outlet socket may be reauired. Cable linking the box 124 to the box 130 can be passed from one to the other using the pull through cord with the connectors which are attached to one end of the cable safely housed within the enclosure 126. The lead or cable assembly is shown at 132 in Figure 12.

The enclosure 126 may be formed from two similar shells 134 and 136 which are held together by means of a band 138 such as an elastic band.

Apertures 140 and 142 in the walls of the boxes 130 and 124 respectively are sufficiently large as to allow the enclosure 126 to pass therethrough either to enter or leave each box as appropriate.

An alternative pull through enclosure for housing connectors is shown in Figure 13 comprising a generally rectilinear box 144 formed from two triangular section shells 146 and 148. Apertures are formed in opposite end faces of the box by means of aligned cut-outs such as 150 and 152 to enable the satellite cable lead 154 to enter the box which then can contain the connectors and other devices attached to the end of the lead. A pull cord 156 and 158 is attached likewise at opposite end faces of the box in the same way as the cord 122 and 128 as secured to the pull through enclosure 126 of Figure 11.

On the four external faces of the box 144, are located four ciaar-shaped rollers 160, 162, 164 and 166. Each is held in position by means of a moulded bracket such as 168.

Where a tube is to be fitted between the central distribution unit and satellite outlets, it is not essential for the tube to remain in position at all times but the tubes can be inserted and removed as required for repositioning. To this end a tube having a ribbed wall such as shown in Figure 14 at 170 may be employed and a pull through cone 172 having a cylindrical section extending from its base shown in dotted outline at 174 may be fitted to the tube if the cylindrical base is formed with an appropriate thread profile to allow it to be loosely screwed into the end of the tube as shown. A pull cord 176 is secured to the nose of the cone 172.

A similar pull through cone is attached at the opposite end of the tube and using standard pull throuqh techniques, the tube can be passed under the floor from one position to another so as to extend therebetween. The two pull through cones such as 172 can then be unscrewed and removed leavinq the tube where it is desired. The ends of the tube can then be fitted to the central distribution unit and to a satellite outlet sleeve such as shown in Figures 1 and 2 and a cable for feeding the work station at the satellite outlet can be fed through the tube from the central distribution unit in the manner in relation to Figures 1 and 2 and to this end a pull cord (not shown) may be built in to the tube 170 so as to always be available for threading cable therethrough.It will be seen that the cones and the tubes are re-usable and in general a pull through cord will be needed between the central distribution unit and each of the satellite positions and must first be in place before the tubes can be pulled into position from the central position.

In Figure 15 a rough flooring screed is denoted by reference numeral 210 on which an elongate metal duct in the form of a shallow tray 212 rests. The upper surface of the tray is covered by a series of metal plates 214, 216, 218 and these are bolted or otherwise secured to the upper edges of the two sides 220 and 222 respectively of the duct 212.

Extending from the side walls 220 and 222 are a plurality of flexible tubes typically of plastics or rubber or metal foil one of which is denoted by reference numeral 224 and another by reference numeral 226.

Each of the tubes 224, 226 etc communicates with the interior of the duct 212 by means of an aperture such as 228 in the wall of the duct and at its other end is fitted with an upstanding right-angle connector outlet one of which is denoted by 230 and another of which is denoted by reference numeral 232.

Each outlet is in the form of a cylindrical right-angled member the upper end of which is flanged as at 234 and 236 respectively and the lower laterally extending tubular section is adapted to receive the outboard end of the tublar member 224 or be fitted therein so as to be joined thereto.

Through each of the tubes 224 an endless loop of cord or tape extends from one end to the other and is left in position during installation. At one point along its length is fitted a cable gripping device such as illustrated at 236 for securing thereto one end of a length of cable (not shown) for threading the cable through the tubular member into the duct 212. The cable can be connected to the appropriate conductors within the duct as at a junction box internally mounted within the duct and at its other end the cable can terminate in a flying socket or in a socket or the like mounted on a table or other piece of furniture or on apparatus which is standing adjacent the aperture such as 234 through which the cable extends.One example is shown at 238 in the drawing which comprises a desk and cables are shown at 240 feeding a pair of power supply sockets 242, a data socket 244 and a telecommunications socket 246. The respective cables shown at 240 pass through a tube (not shown) into the duct 212 to communicate with the respective sections of the duct in which power cables lie, data cables lie and telecommunications cables lie respectively.

The floor is finished by floating a finishing screed across the coarse screed 210 such as is shown broken away at 248. This upper screed is finished to the same depth as the trunking 212 and provides a surface on which carpet or other floor covering can be laid.

Although not shown, the ducting 212 may be located in the space below a suspended floor and each of the outlets such as 230 secured to floor panels suspended above the screed 210.

Also in another embodiment not illustrated, the tubes such as 224 and 226 may be formed within the screed 248 by forming channels therein during the laying of the floor and capping both the channels and the duct 212 by means of floor panels with or without the intermediary of metal panels such as 214, 216, 218 over the ducting.

In each of these alternative arrangements threading of cables through the passages or tubes is effected by means of cords or tapes as aforesaid.

It is to be understood that the satellite outlets 230, 234 and 232, 236 are not necessarily in the form as shown and need not be cylindrical nor right angled. Thus for example they may be in the form of a rectilinear box having tubes entering from the side or the top or the base.

In a similar vein, the tubes 224 need not be flexible but rigid straight or curved tubes may be employed if desired and as mentioned the tubes may be in the form of an elongate cavity through a solid flooring screed which may be as previously described in the form of a channel which is capped by plates or flooring panels, or may be in the form of a tunnel formed through the floor during construction.

Likewise although pull-through cords have been described as being needed to pull the cable(s) through the tubes, if the latter are generally straight or only contain very slight curves, the cords may be dispensed with and the rigidity of the cable(s) may be sufficient to permit it (or them) to be threaded through the tubes or a "chimney sweep type of rod may be employed to push or pull the cable(s) therethrough.

Claims (46)

Claims

1. An underfloor distribution system by which power, voice or data cables can be supplied to any one of a plurality of positions in a floor, comprising: a. an underfloor distribution centre, b. a plurality of cable guides communicating below the level of the floor between the distribution centre and a corresponding plurality of outlet apertures in the floor, c. at least one set of cables extending along one of the cable guides from the distribution centre for supplying a work station located adjacent the outlet, and d. means by which the said cable set can be drawn along the said one guide either (i) into the central distribution centre (after disconnection from the workstation) for feeding subsequently along another one of said guides to exit from another outlet for connection to another work station located adjacent the said other outlet, or (ii) from the distribution centre to the outlet.

2. A system according to claim 1, wherein the underfloor distribution centre has cable connection means therein by which satellite cables can be connected to master cables carrying power, voice or data, at least one set of said satellite cables extending along one of the cable guides from the cable connection means in the distribution centre.

3. A system as claimed in claim 1 or 2r in which each guide is a channel or tunnel in a solid floor.

4. A system as claimed in claim 1 or 2, in which the guides comprise tubes of plastics or metal laid in a space below the floor.

5. A system as claimed in claim 4 wherein the tubes are rigid.

6. A system as claimed in claim 4 wherein the tubes are semi-rigid or flexible.

7. A system as claimed in any of claims 1 to 6 wherein the outlet sockets which communicate with the guides include openable or removable covers which normally close off the outlets but can be opened or removed to permit satellite cabling to extend to an adjoining work station.

8. A system as claimed in any of claims 1 to 7 and further comprising a pull through or draw wire or cord associated with each guide so that the free end of a satellite cable set can be attached to the wire or cord and pulled through the relevant guide from the distribution centre to the chosen floor outlet.

9. A system as claimed in any of claims 1 to 8 wherein plugs or sockets are provided at the free end of each satellite cable set for attachment to complementary sockets or plugs associated with the work station.

10. A system as claimed in claim 9 and further comprising a housing into which the plugs and sockets can be fitted whilst the cable set is to be drawn in either direction along the guide to prevent damage occurring to such plugs or sockets.

11. A system as claimed in claim 10 in so far as it is dependent on claim 8 wherein the housing is attached to a draw wire or cord.

12. A system as claimed in claim 10 in so far as it is dependent on claim 8 wherein the housing is a detachable device which is securable at will to any one of the draw wires or cords and normally remains within the distribution centre ready for use.

13. A system as claimed in any of the preceding claims wherein the guides radiate in a plurality of directions from a distribution centre.

14. A system as claimed in any of claims 1 to 12 wherein all the guides from each distribution centre extend into one defined region centred on or adjacent, or defined by the position of the distribution centre, so that it will always be clear, even when the floor is in place, which distribution centre communicates with which outlets in the floor.

15. A system as claimed in any of claims 1 to 14 wherein the outlets and the distribution centres are colour coded or otherwise marked so that and all of the outlets associated with each distribution centre can be readily identified.

16. A system as claimed in any of the preceding claims wherein each outlet is in the form of a flanged sleeve, the flange overlying the topside of the floor, the sleeve extending through an appropriately dimensioned aperture in the floor and being secured on its underside to the free end of a guide such as a tube by which it communicates with a distribution centre.

17. A system as claimed in any of the preceding claims, wherein the or each distribution centre is in the form of a box supported underneath the floor on height adjustable legs.

18. A system as claimed in any of claims 1 to 16, wherein each distribution centre is in the form of a metal tray the topside of which is open with a flange surrounding and extending outwardly therefrom, and the peripheral flange is securable to the underside of floor panels forming the floor and an appropriately dimensioned floor panel is provided to cover over the open top of the distribution centre box and complete the floor when wiring has been completed.

19. A system as claimed in claim 18 wherein lifting meanns is provided in each panel overlying a distribution centre, so that access to satellite cabling can be gained by simply lifting the appropriate flooring panel.

20. A system as claimed in any of the preceding claims wherein the floor panels are themselves supported on pedestals and the flange around each distribution centre box is trapped between the upper end of two or more pedestals and the flooring members located thereover, and the underfloor distribution centre is itself connected to ducting containing master cabling via its own umbilical feeder, thereby enabling the distribution centre to be moved should it be necessary, by simply removing the flooring panels above and around the distribution centre, lifting the box off the pedestals on which it is carried, relocating it on top of other pedestals and simply relocating the flooring members as appropriate around to cover the space previously occupied by the box and to cover the box in its new position.

21. A system as claimed in claim 1 wherein the floor is made up from a matrix of square floor panels each of which can be lifted independently of the others, and wherein the underfloor distribution system includes flexible tubes forming the guides which communicate between a distribution centre and each of a plurality of outlets, each of which is located near to one corner of one of the flooring panels, so that the outlet can be re-positioned relative to the overall floor by lifting the panel containing the outlet and rotating it until the outlet is in the desired corner position and relocating the panel in the floor.

22. A system as claimed in claim 21 wherein support means is provided to support the tubing below the flooring.

23. A system as claimed in claim 22 wherein feet are attached to the tubes so that the latter are held off a screed or other sub-floor surface.

24. A system as claimed in claim 22 wherein hooks or brackets are attached to the underside of the floor panels in alignment with the tubing runs to support the tube to the underside of the floor panels.

25. A system as claimed in claim 22 wherein cords or wires are stretched between upstanding floor supports and the tubing is attached to or rests on the cables or wires so stretched.

26. A system as claim in claim 25 in which the wires are of elastic material and are adapted to be secured around supporting pedestals and stretched taut therebetween.

27. A system as claimed in claim 10 wherein the plug and socket housing or container is formed by two hemispherical shells adapted to be secured together to form a sphere with the cable ends and plugs and sockets trapped there within.

28. A system as claimed in claim 27 wherein the two hemispherical shells are held together by frictional engagement, by clipping or by means of an endless elastic band located within a circumferential recess in the outer surface of the two shells which is formed when the two shell halves are joined, into which recess the band can slip.

29. An underfloor distribution system by which power, voice or data cables can be supplied to any one of a plurality of positions in a floor comprising guides tracks or rails along which a carriage member can be pulled using an appropriate pull cord to thereby pull along the line of the guide a length of satellite cabling.

30. A system as claimed in claim 29 wherein the guides tracks or rails emanate from a central distribution centre and satellite cabling is pulled frcm the latter to each of a number of desired outlets by attaching the free end of the satellite cabling to a carriage means which is at the distribution centre end of the guide, track or rail and pulling the carriage means by its appropriate pull cord to the far end of its guide, track or rail, so that the free end of the satellite cable set can be retrieved through an outlet associated with the remote end of the guide, track or rail and after being detached from the carriage means the cables can be pulled through the outlet for connection to a satellite work station.

31. A system as claimed in claim 30 wherein the carriage means is pulled back to the distribution centre after the cables have been detached therefrom, to be available to carry other satellite cables to other outlets.

32. A system as claimed in claim 30 wherein the carriage means remains at the outboard end of the guide, track or rail so as to be available for retrieving the satellite cable set by reversing the procedure and pulling the cable set back into the distribution centre when it is desired that it should be relocated.

33. A system as claimed in any of claims 29 to 32 wherein the guide, track or rail is in the form of a curtain-raillike extrusion and the carriage means is similar to the sliders associated with curtain rails for sliding thereby.

34. A underfloor distribution system by which power, voice or data cables can be supplied to any one of a plurality of positions in a floor, comprising a plurality of pull throughs between underfloor boxes, each pull through have associated therewith a container to which the free end of a satellite cable set can be secured during pull through.

35. A system as claimed in claim 34 wherein the container is in the shape of a rugby ball or a box having roller means around its periphery.

36. A system as claimed in claim 34 wherein the pull cords are used to guide and pull through a flexible tube in the first place to serve as the guide for the cable set.

37. A system as claimed in claim 36 wherein each tube has within it its own internal pull cord arrangement whereby a satellite cable set can be pulled through the tube once the latter has been pulled into position.

38. An underfloor cable distribution system in which a single main services duct is arranged to run through or below the flooring and at intervals therealong hollow tubes communicate with the interior of the duct and extend below or through the floor to terminate in cable outlets in the floor, through which cabling can extend from a junction box within the central duct to sockets either at floor level or mounted on furniture or apparatus or walls above the floor.

39. A system as claimed in claim 38 wherein pull through means is provided for use with some or all of the ducts to enable cables to be pulled through the tubes either from the central duct to the flooring outlets or from the latter into the central duct to enable electrical connections to be made between cabling in the central duct and the sockets or apparatus associated with the cable outlets.

40. A system as claimeed in claim 38 or 39 wherein each of the outlets is provided with a removable cap or cover and the pull through means is associated therewith.

41. A method of installing a system as claimed in any of claims 38 to 40 wherein the central duct is in the form of a shallow metal tray the top surface of which can be covered by a plurality of removable plates, and the duct is arranged approximately centrally along an area which is to be served by the cabling before the final floor screed is laid, and flexible lengths of tubing are connected at one end to the side walls of the duct in registry with openings therein to communicate with the interior thereof, and at their other end to angled tubular fittings which sit on the rough screed with their open ends pointing upwards so as to occupy substantially the same plane above the rough screed as is the upper surface of the duct, and the final screed forming the floor is then poured or otherwise formed on either side of the central duct and over and around the tubes and around the angled outlets so that when the floor is finished, only the top surface of the duct and the upwardly directed openings of the angled outlets are visible.

42. A method of installing a system as claimed in claim 38, 39 or 40 wherein the duct is located on a screed which itself provides a base for a framework above which a floor is carried, the tubes connecting the duct to the various outlets not only run in a generally horizontal plane but also in an upward manner to the outlets which themselves are fitted into apertures in the supported flooring.

43. A system as claimed in any of claims 38 to 40 wherein the tubes extending from opposite side of the duct are replaced by channels in a concrete or other solid screed the thickness of which is commensurate with the height of the duct and rigid plates cover the duct and the channels in the screed, the channels and the cover plates defining the passages through which the cabling can be pulled.

44. A system as claimed in claim 43 wherein floor panels provide the cover for the duct of overlay the plates which cover the duct.

45. A system as claimed in claim 44 wherein the outlets for the ducts are formed in the flooring panels and comprise holes in the panels which register with the ends of the channels in the screed below the flooring panels, and flanged sleeves with covers are provided in the flooring panels to define the outlets and provide a neat trim thereto for decorative purposes.

46. Underfloor trunking systems contructed and arranged substantially as herein described with reference to and as illustrated in the accompanying drawings.