WO1996030697A1

WO1996030697A1 - Modular cable duct for lighting and for transport of multipurpose electric cables

Info

Publication number: WO1996030697A1
Application number: PCT/IT1995/000074
Authority: WO
Inventors: Nicola Scotti
Original assignee: Sesti Impianti S.P.A.
Priority date: 1995-03-28
Filing date: 1995-05-16
Publication date: 1996-10-03
Also published as: AU2418995A; IT1274370B; ITMI950624A0; ITMI950624A1

Abstract

Modular electric duct comprising modules (11) in two longitudinal compartments, the front one, B, being used for illumination and the rear one, A, for transport of electric current for power purposes, controls, transmission, including longitudinal self-carrying structural channel-shaped elements (15), reflection (71) and diffusion (61).

Description

MODULAR CABLE DUCT FOR LIGHTING AND FOR TRANSPORT OF MULTIPURPOSE ELECTRIC CABLES

The invention concerns equipment for lighting and for housing cables carrying efpctric power as well as weaker and medium-strength currenlt used for warnings, controls, elecommunications, transm ssion of current in general.

Since electrical equipment; is a basic need for making indoor and outdoor environments habitable and operative, the main problems to solve in so doing comprise the ne- cessity for sources of lighting to co-exist with cables carrying energy. Sources of light must be placed where the light rays can be most efficiently used and give the best effect in compliance with continuous evolution of social needs. Transport of the required electric energy presents some considerable problems of insulation and the earthing of induced current, as well as providing installations com^¬ patible with propriety and an appearance pleeasing to the eye Other problems are caused by weather conditions, and by salty and chemical agents generally, especially where humidity is also present. Presently known electrical plant and equipment can pro¬ vide efficient lighting, keeping wiring out of view but generally paying a high cost for doing so. For this reason the best solutions for lighting often have to be given up due to excessive cost of materials and ins allation, par¬ ticularly so for large-scale plant in aggressive outdoor environments such as stations, airports and the like. The above invention solves these problems offering origi¬ nal, effective and inexpensive solutions as will be explained below.

Subject of the invention is a modular duct for electric cables that comprises two main longitudinal compartments, a front one for illumination and a back one for transporting current, for control purposes and transmission. The various modules are composed of longitudinal channel-

-shaped pieces, to be called 'channels' , preferably plastic produced by pultrusion, namely by drawing a bundle of open work fabric and roving, comprising fibreglass-re inforced plastic (FRP), through a heated die to give maximum strength against bending, maximum rigidity and capacity to retain the original shape, maximum strength while, at the same time, being thin and. light in weight.

The channels are associated with others of polished alumin¬ ium of a parabolic cross section, and another of lenticular shock-res i s ent polycarbonate ideal for light diffusion.

These modules are self-carrying and can be used for light¬ ing purposes both separately and associated, aligned, for indefinite and practically unlimited lengths in accordance with illumination requirements and individual needs. In one preferred type the cable duct exhibits a substan^¬ tially constant right-angled cross section divided into two subsections; the front one takes the form of a right- angled triangle whose base is in common with the lesser base of the substantially trapezoidal rear subsection whose longer base corresponds with that of the right- angled section. Position of the front subsection corresponds with that of the front compartment used for illumination and the rear subsection with the rear co parment used for services. The central angle at the base of the transversal section is slightly less than 180° and this creates, in the duct, a rear wall formed of two slightly sloping planes.

The base of the triangular subsection also exhibit.', a cen¬ tral angle of a value substantially equal to that of the base of the section so that the bases of the triangular section and triangular subsection are substantially of the same shape with some parts being parallel.

The plastic channels comprise structural base bars that also serve for covering and fixing.

Both types are mounted in pairs, one opposite the other, and symmetrical in relation to an axial geometrical plane. The cross section of the structural base bars is shaped like a large "C", open towards the rear of the duct and composed of a central substantially straight part with one straight side at an angle slightly greater than 90° and the other side at an angle of about 130°. At the end of the first side is a fin bent outwards at

90° and then at 180° to form first a tongue, hen a niche. The second side is connected to the central part after said part has made a bend of about 30°, and at its end is a fin bent inwards at 90° to form a C-shaped channel open- ing outwards and lying at practically 45° in relation to the rear side of the cable duct. At the end of the fin is a groove shaped lika a small "c" and opening outwards. The structural base bar here described is associated to another bar subs antially the same, one placed opposite to the other, both matching externally, at the 90° angles created by the first side and by the fin, with a squared U-shaped bar facing towards the inside of the duct and in line with it.

The above association is stabilized by various means such as glueing and mechanical joining and forms a squared U-shaped channel facing inside the duct and substantially as a continuation of the U-shaped bar that determines said association.

Centrally in the large "C" the structural base bars exhibit an orthogonal partition, fixed by means of a right-angled extension, that substantially divides the space, formed by said C-shaped base bar, into two secondary compartments.

The main rear longitudinal compartment of the duct is thus divided into four secondary compartments into which as many as four classes of cables can be placed for carrying energy and for the various services. The covering pieces are substan ially flat and have at one end a tongue created by a double curve at 90° in both di^¬ rections and, at the other end, a longitudinal rib ith a head that projects on the same side as that of the tongue. This cover is applied to the base bar by fitting the tongue inside the niche created at the end of the first side of said base bar and by fitting the head on the rib into the small "c"-shaped groove to be found at the end of the base bar's second side. With the covering piece the C-shaped base bar is closed, therefore closing the service compartments as well.

Inside the squared U-shaped channel, formed by association of the two base bars, another squared U-shaped channel is inserted, this latter facing outward and having at its ends a pair of fins, one facing the other, and a second pair of fins facing outward and slightly projecting at a short distance from the external planes created by the base bars .

The purpose of the pair of fins facing each other is to make it possible to fix the means for holding the lamp- holders for one, two or more lamps placed axially and longitudinally in the cable duct. The purpose of the second pair of fins is to allow the parabolic reflector to be attached.

The front compartment, used for illumina ion, is obtained from a piece of lenticular polycarbonate shaped like a diffuser having a substantially V-shaped* transversal section open at 90°.

Two fixing bars, one on either side of the rear compart¬ ment, are placed for application of the polished aluminium channel and the lenticular polycarbonate diffuser to the base channels that create the rear compartment to be used for services.

One of these fixing bars has an external cross section substantially V-shaped and an internal section in the form of a small "c", there being at the tip of the "V" a tongue that branches into a hook and a fin, facing opposite ways, substantially parallel to one side of the "V".

The other fixing bar's cross section is substantially in the shape of a "T", the leg being formed of two tongues with lateral projections. At the angle formed between the main length of the base channel and its end at 30° is an external rib with a head to i t . It is thus possible to mount the first fixing bar on the base channel, fitting said rib with its head inside the "C" present in the first fixing bar and this ope¬ ration orientates the hook at the end of said fixing bar towards the inside of the duct, and also orientates the opposite facing fin towards a tooth made on the outside of the base channel at the right angle it forms with the external side.

A slot is created between said fin and said tooth into which the leg of the second fixing bar can be fitted. At the ends of the polycarbonate diffuser piece a fin is formed by two 45° bends made one after another in opposite directions.

In this way it is possible to fix said polycarbona e diffuser to the duct's rear compartment for services, inserting said tongues on the diffuser between the fin on the first fixing bar and the head on the second one. This latter, fitted in between the fin on the first fix¬ ing bar and the tooth on the base channel, stabilizes the diffuser in its position. The polished aluminium reflector is formed of a parabolic structure made from two identical pieces to be mounted one opposite the other by fitting in - between the out¬ ward facing fins - the U-shaped channel inserted in the other U-shaped channel formed by association of the two base channels, and the hook on the end of the first fix¬ ing bar .

Adequate packing is placed at all longitudinal housing slots, for associating the various channel-shaped pieces and particularly the base channels, on the cover and on the second fixing bar, to ensure a seal against external agents . The modules are associated by axial alignment stabilized by fixing devices that use the C-shaped housing slots formed at the rear ends of the service compartment. Said device is composed of a pair of short bars, one to fit inside the above C-shaped channel and the other to lie outside said "C".

Association of the aligned modules is stabilized by screws passing into holes made in the outer short bar and which then screw into threaded holes in the inner short bar. For holding the modular electric duct to the various struc- tures present in the areas to be illuminated, the C-shaped channels formed at the rear ends of the services conparment are used together with a device composed of a small plate, to be placed inside the C-channels, and a square to be placed outside. Association between said square and said plate is made by a screw that passes through a slot in the square and then screws into a hole for it in the plate.

By means of a hole made in the square the duct can be at¬ tached to the structure by fixing said device at the most suitable position on the C-shaped channel as dictated by circumstances and preferences.

The material used for the pieces obtained by pultrusion is self-extinguishing in compliance with UL 94 regulations for class V0 and that for the diffuser is self-extinguishing in compliance with the same regulations for class V2.

The degrees of protection offered by the modular electric duct range from IP 4 X to IP 65.

In other preferred executions the cross section of the modular electric duct takes various polygonal, circular or mixed forms, with arched areas, said section being then divided into two subsections respectively corresponding to the main compartments for illumination and for housing cables, these too of different polygonal forms. The various modules can also be composed using longitu¬ dinal base channels of steel or extruded aluminum, and associated to reflecting channels of polished aluminium or of other material of a parabolic section and to a diffuser piece preferably of lenticular shock-resistant polycarbonate .

The invention offers evident advantages.

The described cable duct represents a real backbone in arrangements for distribution of electric and similar sys ems .

The rear compartments, separated one from another, can house circuits of different voltages for lighting, power, BTS, warnings, clocks, TVCC, sound diffusion and others. The front part accommodates a source of light that is practically continuous and can be as long as desired. Various meterials such as steel, extruded aluminium, FRF can be used. The constant transversal section can be chosen as desired from among shapes such as triangles, rectangles, semi- arches and various polygons.

The version made of unsaturated FRF using the pultrusion technique provides an apparatus fully satisfying safety regulations where environmental conditions are most severe The duct can be made in various standard lengths, even up to six or more metres long.

It offers very high resistance to weathering, to salty air and to most chemical agents, and an excellent capacity for withstanding corrosion permitting installations to be set up in conditions of high humidity, in tunnels and outside. The duct can also be used where foodstuffs are stored as the resin is neutral in contact with these products. Its high resistance to temperatures ensures prolonged protection of the cables if an outbreak of fire occures outside the structure, and at the same time maintains good dispersion of heat. There is no need to ground the structure or cover parts, nor are induced currents present or any effect on means for protecting buildings from atmospheric disturbance. Reduced weight facilitates transport and installation. To sum up these advantages: the invention offers a fully rational system which, at a low cost, solves problems both of optimum environmental lighting and of transport of electricity for power and purposes of control. Characteristics and purposes of the invention will be made still clearer by the following example of its exe- tion illustrated by diagrammat ically drawn figures. Fig.1 Modular electric duct, cross section. Fig.2 Perspective view of the duct, from above. Fig.3 Perspective view of a detail of the join between modular parts of the duct. Fig.4 Perspective view showing a detail of how the duct is mounted on the structure carrying it. Fig.5 An exploded perspective of the duct.

The modular element 11 in the duct 10 substantially shaped like a triangular prism, comprises a rear compartment A substantially in the shape of a trapezoidal prism and a front compartment B substantially in the shape of a tri^¬ angular prism whose base coincides with the lesser base of the trapezium . The compartment A is used for carrying multi-purpose cables while the compartment B is used for illumination.

All parts of the module 11 in the duct 10, mounted in pairs will be indicated by the same number. The same applies to the paired parts of such pieces. The compartment A consists of a pair of base channels 15, substantially the same, placed symme rically on either side of a C-shaped channel 50 to which they are joined by glueing or by mechanical means.

The longer side 16 of the channel 15 is connected, at an angle slighter greater than 90°, at one side 17 with side 18 at 90° which, by making a second 180° bend, forms the tongue 19 and a niche 20. On the opposite side, said longer side 16 exhibits an end 21 angled at practically 45° which is connected to the second side 22 angled, in relation to the central axis of the cross section, at abour 45°. Said side 22 is about as high as side 17 and, at its end, has a fin 23 at 90° that forms a "C" 24 opening outwards and, laterally and externally to the "C", a groove 25 shaped like a small "c".

Inside the bend at the end between the side 16 and its end 21 is a rib facing outward and with a head 26 on it. The large channel created by parts numbered 15 is closed above by a covering piece 30 which at one end has a fin 31 made by two 90° bends in opposite directions and, at the other end, a rib with a head 32 on it facing the same way as the fin 31. Said covering piece 30 is applied to the channel shaped part !5 by fitting the fin 31 into the niche 20 and then pressing the head 32 on said rib inside the groove 25 at the end of the base channel 15. About half-way along the base side 16 a partition 35 is raised orthogonally supported by a short right-angled section 36 that divides the channel created by the part 15 into two longitudinal compartments. - I 1 -

Four compartments a,b,c,d are thus formed, all made from the main compartment A.

Through compartments a,b,c,d the cables for different purposes can be made to pass; purposes such as transport of energy for lighting, weak and medium-strengh current for warnings and whatever else the type of installation may require .

The sides 17 of the two base pieces 15 form a U-shaped channel 38 into which is inserted another, 40, shaped as a squared "U" .

At the end of this squared "U" is a pair of tongues 4 I facing one another, and a second pair of tongues 42 facing the opposite way at a short distance from the external plane formed by the sides 16 of the base channel 15. Lampholders 46 can be fitted, by suitable holding means 44, to said opposing tongues 41. These lampholders are for lamps such as 47, 48, 49.

The lamps, aligned one with another, are placed all along the cable duct producing a continuous source of light whose length can be determined at will according to the number of modular elements needed to light up the area concerned .

The diffuser with a triangular cross section 60 and the parabolic screen 70 made from two shaped pieces 71 substan- tially the same, are mounted on the structure formed by association of the two base channels 15 that form the rear service compartment A, to complete the main compartment B for illumination, by means of the fixing bars 80 and 90. Fixing bar 80 is formed of a V-shaped body 81 within which is a C-shaped groove 82, and of a rear tongue 83 set at about 90° to one side of the "V", at whose end project a hook 84 and tongue 85 facing away from the hook that lies substant ial ly parallel to said side of the "V". Said fixing bar 80 is mounted outside the base channel 15 by means of the rib with head 26 made at the point of the hollow created by the angle of the end of length 16 of said base channel 15.

During mounting of the fixing bar 80, this head 26 fits inside the groove 82.

As clearly appears from Fig.1, during mounting the hook 84 assumes a position in opposition to the tongue 42 made at the end of the central U-shaped piece 40 mentioned above. The parabolical bodies 71 can therefore be mounted between said hooks 84 and said tongues 42, formed at the two ends of the structure obtained by association of the two chan¬ nels 15, as seen in fig. l. The two bodies 71 therefore make up a parabolical screen 70. The diffuser body 60 has, at its two ends, tongues 61 formed by a double bend at 45°.

When mounting is in progress siaid tongues fit into the space created by the hook 84 and fin 85 on the fixing bar 80.

Fin 85 remains opposite a tooth 29 at the outer end of the base channel 15 at the side 22.

Between said fin 85 and tooth 29 a longitudinal groove is created within which to fit the leg of fixing bar 90, made from two parallel elastic tongues 91,92 with raised ends.

Mounting said fixing bar 90 therefore stabilizes application of the diffuser 60 as may be seen in Fig. I. Packings 45,46,47 are placed inside the niche 20, inside the groove 25 and in the space between the tongue 61 on the diffuser 60 and the head on the fixing bar 90, to provide a protective seal against external agents. The diffuser 60 is lenticular and is made of shock-res i s tant polycarbonate stabilized by UV rays.

The modular elements ( 1 Ornay be of various lengths, as pre¬ ferred, even several meters long, since the shaped pieces, especially the base channels, are made by pultrusion, a technique that consists in pulling a bundle of open-work fabric and roving, comprising threads and fibres of FRP, through a heated die.

The her o-hardened plastic material, raised to a tempera¬ ture at which the polymer component completes a non-reversible reaction, assumes a reticular three-dimens ions 1 structure of great rigidity. The hardened material is continuously extracted from the die by traction.

This process ensures a static load, rigidity and resistance to gusts of wind which makes possible installation in prac- tically any place.

Associating modular elements of different or equal lengths, aligning them along the longitudinal axis, produces a con^¬ tinuous duct useful for both lighting and carrying electric power at the same time. In addition weak and medium-strength current for various purposes may be carried.

The different parts 11 are connected by the devices 100 com^¬ prising the short bars 102 which fit inside the C-shaped channels 24 at the two ends of elements 11 and 11 ' and the short bar 101 which adheres outside said ends of the C-shaped channe1.

Obviously the short bars 101 and 102 are placed at the two joined ends of two contiguous modular elements. Screws 103, 104 pass through holes 105 in the short bar 101 and, after being tightened in the threaded holes 106 in the bar 102, make a stable and secure association between con¬ tiguous modular elements. Externally to the line of junction along the entire length of both the base channels 15 and of the diffuser 60, of two modular elements 11, a band 110 is placed that com¬ pletely covers the junction area, if necessary adding suitable packing, and forms a protective seal among the associated modular elements 11.

By means of the C-shaped channels at the two ends of the modular elements 11, the cable duct can be easily and securely anchored to any structure aided by the device 120 formed of a plate 121 placed inside the C-channel 24 and square 122 whose base 123 is made to adhere to the outside of the "C".

The screw 124 passes through a slot 125 in the square and is then screwed into a threaded hole in the plate while the hole 126, present at the other end of the square,makes possible fixture to suitable receiving parts prepared on the structure.

A modular element or a duct made from different modular elements, is closed at the ends by a plate 130 of a sub¬ stantially triangular form that corresponds to the form of the cross section of the modular elements, finished by a rim 131 round an internal cavity of a size corresponding to the external dimensions of the ends of said modular ele¬ ments . As the above invention has been described and explained as merely an example not limited to this, and to show its essential characteristics, it is understood that numerous variations may be made to it in accordance with industrial, commercial or other needs, and other systems and means em¬ bodied in it without departing from its sphere of action. It is therefore stated that the application to patent in^¬ cludes any equivalent application of the concepts or of products executed and/or in use according to any one or more of the haracteristics indicated in the following claims.

Claims

CL AIMS

I. Electric duct (10) formed of modules ( I I) characterized in that it comprises two main longitudinal compar men s, a front one B to be used for illumination and a rear one A to be used for carrying electricity for power, controls, transmission purposes, services generally.

2. Electric duct ( 10) formed of modules ( 11) as in claim 1 characterized in that it comprises two main longitudinal compartments, a front compartment B for illumination and the other A behind the first, for transport of electrici¬ ty for power, controls, transmissions, services generally, the various modules( 1 l)being composed of self-carrying longitudinal channel-shaped pieces ( 15) which can be used either separately or aligned for association, in indefinite and practically unlimited lengths according to the places where lighting is required or to individual needs.

3. Electric duct ( 10) formed of modules( l l) as in claim 2 characterized in that the various modules ( I I) are con¬ stituted of longitudinal structural ( 15), reflecting (70) channels, especially of a parabolic cross section, for re¬ flection of light, diffusers (60) for diffusion of light, covering pieces (30) for closing the rear compartment, and of fixing bars (80,90) for said reflecting (70) and dif¬ fusing (60) shaped pieces.

4. Electric duct ( 10) formed of modules( I l) as in claim 3 characterized in that the longitudinal and especially the structural channels ( 15) are produced by pultrusion of FRP and therefore by drawing a bundle of open-work fabric and roving through a heated die in order to obtain maximum re- sistance to bending stresses, maximum rigidity and ability to maintain the original shape, maximum strength though thin and light in weight.

5. Electric duct( lθ) formed of modules ( 11) as in claim 3 characterized in that the reflecting parts are made of po¬ lished aluminium.

6. Electric duct( lθ) formed of modules( l l) as in claim 3 characterized in that the longitudinal diffuser channels

(60) are made of lenticular shock-resistant polycarbonate.

7. Electric duct(lθ) formed of modules( l l) as in claim 3 characterized in that the longitudinal channels, especial¬ ly the structural channels ( 15) are composed, as may be required, of thermohardening plastic, steel laminae or extrused aluminium.

8. Electric duct( IO) formed of modules ( 1 I ) as in claim 1 charac erized in that it exhibits a constant cross section substantially in the form of a right-angled triangle di- vided into two subsections, a front one in the form of a right-angled triangle whose base is in common with the lesser base of the rear subsection of a substantially tra¬ pezoidal form whose greater base is in common with the base of the right-angled triangular section, the front subsection corresponding to the lower compartment B to be used for il¬ lumination and the rear subsection corresponding to the upper compartmant A to be used for services.

9. Electric duct( IO) formed of modules ( 1 I ) as in claim 8 characterized in that the base of the cross section exhi- bits a central angle slightly less than 180° so as to form, in the duct ( 10), a rear wall having two slightly inclined planes, the base of the triangular subsection also having an angle of a value substantially equal to that of the base of the cross section, so that the bases of the triangular section and of the triangular subsection are substantially of the same form and parallel in some lengths.

10. Electric duct( lθ) formed of modules( l l) as in claim 3, characterized in that the structural channels ( 15), the parts for covering (30) and reflecting (70), the fixing bars (80,90) are mounted as pairs, one opposite another, and symmetrical in relation to an axial geo- metrical plane.

11. Electric duet ( 10) formed of modules( l l) as in claim 3 characterized in that the structural base channels ( 15) have a section shaped like a large "C" open towards the rear of the module ( I I) and composed of a central sub- stantially straight length ( 16) with a straight side ( 17) at an angle slightly greater than 90°, and another side (22) at an angle of about 130°, the first side ( I7)ha- ving a fin ( 18) bent outwards at 90° and again at 180° thus forming a tongue ( 19) and then a niche (20), the second side (22) being connected to the central part( 16) after it has made a bend of about 30°, said second side having at its end a fin (23) bent inwards at 90° which forms a C-shaped groove (24) open outwards and at about 45° in relation to the rear part of the duct, said fin (23) having at its end a groove (25) shaped like a small "c" open outwards, each base channel being associated to another s bstantially equal channel placed opposite it so that both channels ( 15) match, externally, at the 90° angles created by the first side ( 17) and by the fin ( 18), with a squared U-shaped channel (50) facing towards the inside of the module ( 11) and in line with said module, said association being stabilized by various means such as glueing and mechanical joins, said associa^¬ tion giving rise to a squared U-shaped channel (38) facing towards the inside of the module ( 11) substan ially con^¬ tinuing the U-shaped part (50) that determines associa- between the two structural base channels ( 15).

12. Electric duet ( 10) formed of modules( I I) as in claim I I characterized in that the structural C-shaped base chan¬ nels ( 15) exhibit, practically in the middle of the cen¬ tral length ( 16), an orthogonal partition (35) fixed by means of an appendix at 90° that substantially divides the space made by said C-shaped base channel( 15) into two secondary compartments (a,b) (c,d) so that the main longi¬ tudinal rear compartment A of module ( 11) is divided into four secondary compartments (a,b,c,d) to accommodate as many as four classes of cables for carrying electricity and for the various services.

13. Electric duct ( lθ)formed of modules( l l) as in claim 3 characterized in that the structural base channels ( 15) comprise a substantially flat covering part (30) at one end of which is a tongue (31) created by a double bend at 90° in opposite directions, and at the other end a longi¬ tudinal rib with head (32) projecting on the same side as the tongue ( 3 I ) , said covering part (30) being mounted on the base channel ( 15), the tongue (31) being fitted inside the niche (20) formed at the end of the first side( 17) of the base channel ( 15) and the head (32) on the rib being fitted inside the small c-shaped groove (25) at the end of the second side (22) of the C-shaped base channel ( 15), said covering part (30) closing the base channel ( 15) and therefore also the compartment A used for services.

14.Electric duct ( I0)made of modules( l l) as in claim 11 characterized in that inside the square U-shaped channel (38) formed by association of the two base channels ( 15), a similarly squared U-shaped channel (40) is inserted, this latter facing outwards and having at its ends a pair of fins (41), one facing towards the other, and also a second pair of outward facing fins (42) projecting at a short distance from the outer planes created by the base channe1 (15), the purpose of the pair of fins (4 I ) facing one towards the other being to make it possible to fix the means (44) for holding the lampholders (46) for one (48) two or more lamps (47) arranged axially and longi udinally in the module ( I I), the purpose of the second pair of fins (42) being to make it possible to mount the parabolic re¬ flector (70) .

15. Electric duct( lO)made of modules( l l) as in claim 1 characterized in that the front compartment B to be used for illumination is made from a piece (60) of lenticular polycarbonate shaped as a diffuser the cross section of which is similar to a "V" open at 90°.

16. Electric duet ( 10) made of modules( 11) as in claims 3 and 11 characterized in that to apply the reflecting parts (70) and the diffuser (60) to the base channels ( 15) that create the rear compartment A to be used for services, two fix¬ ing bars (80,90) are placed one on either side of the rear compartment A, said fixing bars consisting, in one case(80) of a part whose external cross section is V-shaped (81) and whose inner one is shaped like a small "c" (82) that exhibits at the tip of the "V" a tongue (83) from which branches off a hook (84) and a fin (85) in the opposite direction substan ially parallel to one side of the "V" (81), and in the other case a fixing bar (90) of a substan¬ tially T-shaped cross section whose leg (91,92) is formed of two tongues with lateral projections, there being at the angle created by the main length ( 16) of the base chan^¬ nel ( 15), and at its end at 30°, an external rib with head (26) so that the first fixing bar (80) can be mounted on the base channel ( 15) fit ing the head (2όj on said rib inside the "c" (82) present in the first fixi g bar (80 ), said mounting turning the hook (85) on the end of said fixing bar (80) towards the inside of the module ( I I) and turning the fin (85) in the opposite direction towards a tooth (29) made on the outside of the base channel ( 15) at the angle at 90° with the outer side (22), there beinj created between said fin (85) and said tooth (29) a groove within which to fix the leg (91,92) of tn» second fixing bar (90), there being made at the ends of the diffuser part (60) a tongue (61) formed by two successive bends at 45° in opposite directions, it being thus possible to fix said diffuser (60) to the rear compartment A to be used for services in the module (\ \) by inserting said tongues (61) on the diffuser (60) between the fin (85) on the first fixing bar (80) and the head on the second fixing bar (90) and this latter, being inserted between the tongue (85) on the first fixing bar (80) and the tooth (29) on the base channel ( 15), firmly mounts the diffuser (60) in position.

17. Electric duct ( 10) made of modules ( I I) as in claims 5, 14 and 16 characterized in that the longitudinal reflecting chan¬ nels are formed of a parabolic structure made from two equal channels (70) to be mounted one opposite the other by fitting them between the o tward facing fins ( 2), on the squared U-shaped channe1 (40) inserted within the U- shaped channel (38) created by association of the two base channels ( 15), and the hook (84) made at the end of the first fixing bar (80).

18. Electric duct ( 10) made of modules ( I I) as in claims 11, 13, 15 and 16 chara terized in that at all the longitudinal joins (20) (25) (85-90) for association of the base channels ( 15), - 2 I -

of the covering parts (30) and of the second fixing bar (90) suitable packing is applied to ensure a weather-proof seal .

19. Electric duct( 10)made of modules( l l) as in claim 11 characterized in that the various modules ( I I) are asso¬ ciated by axial alignment said association being made stable by fixing means that use the "C" shaped channels (24) at the rear ends of the compartment A for services, said means consisting of a pair of short bars, one ( 102) being placed inside the C-shaped channel (24) on the two aligned modules ( I I) and the other ( 10!) being placed outside said "C", association of the aligned modules ( I I) being made stable by screws ( 103) put into holes passing through the outer short bar ( 101) and then scre ing into corresponding threa- ded holes in the inner short bar ( 102).

20. Electric duct( lθ) made of modules ( I I) as in claims I and I I characterized in that to fix said modular electric duct ( 10) to the various structures present in the areas to be illuminated, use is made of the C-shaped channels (24) at the rear end of the compartment A for services and of a device consisting of a plate ( 121) to be inserted inside the C-shaped shannels (24) and of a square ( 120) to be placed outside, association between said square ( 120) and said plate ( 121) being made by a screw ( 124) passing through a slot ( 125) in the square ( 120) which screws into a hole in the plate ( 121), a hole ( 126) made in the square ( 120) permitting the duct ( 10) to be held to the structure, said device being fixed at the most suitable position in the C-shaped channel (24) according to circumstances.

21. Electric ducc( lQ) made of modules( I l) as in claim 4 characterized in that the material used for the shaped parts ( 15,30,80,90), obtained by pultrusion, possesses the characteristic of being self-ex inguishing in compliance with regulation UL 94 class V0.

22. Electric duct ( 10) made of modules( l l) as in claim 6, characterized in that the material used for the diffuser

(60) is self-extinguishing in compliance with regulation UL 94 class V2.

23. Electric duc ( 10) made of m dules( l l) ad in claim I characterized in that it offers a degree of protection from IP 4 X to IP 65.

24. Electric duct( lθ) made of modules( l l) as in claim 1 characterized in that its cross section may be variously polygonal or circular or mixed with arched areas, divided into two subsections respectively corresponding to the main compartments for illumination, B, and for housing the elec¬ tric cables, A, these too being of various shapes.