State of the Art The prefabricated electrical conductors are electric lines extending in space according to set routes. They are usually composed of straight and angular elements joined together consecutively to follow the desired route, installed with the aid of accessory components. The route created serves to transport electricity in general and for distributing the same to usage points connected by by outlet junctions. For this distribution of the current some conductor elements are provided with a means of connecting one or more connection boxes. The elements forming these prefabricated electrical conductors are normally composed of a housing, also called a profile, open on one side, bus bars running through the housing or profile, and a cover or closing element on the open side of the housing and fixed to the same by welding.

The conductor bars include phase bars, neutral bars and ground bars: these latter bars acting as protection bars. All the bars are covered with insulation sheath to prevent direct contact with them. In order to form an electrical conductor following the desired route, the conductor elements are joined together consecutively by an electrical and mechanical joints.

The electrical joint is a connection, also known as joint block, which is

made up of two side walls and between them individually insulated plates forming a pack. Said plates are in the inserted manner of combs into the divaricated ends of the conductor bars of every two adjoining elements and then fixed to said bar ends.

The electrical joint is usually connected with the end of each conductor element (except for the last) so as to be preset to receive the end without a joint of the bars of another contiguous conductor element.

The mechanical joint is made using a flange to be connected to the housing and cover of the contiguous conductor elements usually by screws.

The electrical joint is completed with a locking bolt passing through the joint block and it is tightened to create a tightening torque suitable for guaranteeing close contact between the bars and the joint.

However, the electrical connection of the contiguous conductor elements, using a junction box, as in a standard practice, is not without disadvantages and problems. For example, as soon as the locking bolt fixing the junction box to the bar loosens, the junction tends to uncouple and separate from the element it is connected to. This obviously makes its coupling and joining with the bars of the continuous, that is successive element more difficult or at least not easy. In addition, the contiguous elements must be joined, maintaining a certain distance between them to allow linear dilation of the system. This envisages a control over the insertion depth of the opened ends of the bars between the two plates of the joint block. However, at present, neither the conductor elements nor the joint block are provided with systems to view and however definitely limit the coupling of the contiguous elements, therefore the distance between these is left up to the operator, who, anyway, already has to pay attention, for the

reasons already mentioned above, that the joint block does not uncouple from the bars.

Objectives and Summary of the invention One objective of the invention is to remedy the above problems and disadvantages Indicated in the known technique so as to facilitate and make positioning, coupling and joining of the components to be fitted together decidedly easier.

Another objective of the invention is to provide a simple and efficient device capable of positively and permanently attaching the joint block to the conductor elements to be joined together, without the joint block uncoupling should the anchoring bolt become loose.

Another objective of the invention is to supply an anchoring device for the composition of the prefabricated electrical ducts, equipped with a means of establishing the closeness of the contiguous elements, and which retracts after tightening the joint so as not to be of a hindrance and allow linear dilation of the duct formed.

These objectives are achieved, according to the invention, by an fixing device which includes one, two, or more suspension pins on each side wall of the joint block, designed to engage with a corresponding hole formed in the opposite sides of the housing or profile of a conductor element, and a spring spacer associated with the fixing block, passing through the joint block and designed to be located between the housings or profiles of two contiguous conductor elements to limit the approach when they are coupled to the joint block.

Brief description of the drawings

Greater detail of the invention will become clear from the continuation of the description made with reference to the enclosed indicative and non-limiting drawings, in which: Fig. 1 is an exploded view of the components of a linear conductor element; Fig. 2 is an exploded view of the components of a block joint; Fig. 3 is a view of the block joint, as assembled; Fig. 4 is a view in perspective of a conductor element and joint block linked together; Fig. 5 and 6 show, respectively, side and top views of the assembled elements in Fig. 4.

Fig. 7 is a cross-section view in direction of the arrows A-A in Fig. 5, at the level of the suspension pins; Fig. 8 is an enlarged view of a suspension pin encircled in Fig. 7 Fig. 9 and 10 show, respectively, the side and top views of two elements joined together by a block joint; and Fig. 11 and 12 show a cross-section view in direction of the arrows B-B in Fig. 9, before and after tightening of the anchoring bolt.

Detailed description of the invention In the drawings, a conductor element 20 and a block joint 21 are represented.

The element 20 comprises a housing or profile 22, conductor bars 23, insulated from each other, placed in said housing through an open side in the latter, and a covering or cover 24 for closing the open side of the housing-Fig.

1,4.

The block joint 21 comprises a number of plates 25, insulated from each other, positioned as a pack between the two side walls 26 with a fixing bolt 27-Fig. 2,4 passing through it.

The conductor element 20 and joint block 21 are joined together by inserting the widened ends of the bars 23 of the first between the plates 25 of the second, and then attached to each other by tightening the fixing bolt 27- Fig 5 and 6.

The housing 22 of the conductor element 20 normally has two opposite side walls 28, and according to the invention each one of them is provided with at least a pair of holes 29 vertically not in line, at each of the ends.

On each side wall 26 of the block joint 21 there are two suspension pins 30 which is designed to enter the holes 29 of one of the side walls 28 of element 20. The suspension pins 30 on each side wall 26 of the block joint 21 are vertically out of line in the same way as holes 29 which have to receive them. This feature establishes without any doubt the coupling direction of the block joint with each conductor element, facilitating assembly for the operator.

Each suspension pin 30 stressed by a thrust spring 31, both placed in a housing 32 formed in the respective side wall 26 of the block joint 21-Fig. 7 and 8. The pin 30 can move between a position projecting from the side wall 26 to a retracted position in its housing 32. The projecting position is usually provoked and maintained by the thrust spring 31 and limited by a stop 33 attached to the pin. The retracted position is achieved by pressing the pin 30 in the direction of the arrow F in Fig. 8.

The head of the anchoring bolt 27 works in conjunction with a vertically facing flexible spacer 34, shaped like a leaf spring, that is arch shaped, and with

a set width. The intermediate part of the spacer 34 rests directly or indirectly against the head of the bolt 27. The opposite ends of the spacer 34 rest against the block joint 21 walls and each end in a fin 35 facing outwards and preferably not as wide as the rest of the spacer. When the suspension pins 30 are retracted in their respective housings they pass between the side walls 28 of element 20. In this way the block joint 21 can be coupled to the bars 23 at the end of the respective element 20 until the pins 30 are thrust into the corresponding holes 29. The block joint 21 will in this way remain engaged and attached to element 20 even should the fixing bolt 27 become loose because of the coupling of a second conductor element 20'to the block joint itself.

When the fixing bolt 27 is loose, the flexible spacer 34 is not loaded, flexed and projecting from the wall 26 of the block joint it is resting against-Fig.

11. In this way it forms a means of checking and longitudinal positioning of the second element 20'to be coupled as a continuing part of the first element 20 already coupled to the block joint 21-Figs. 9 and 10. Afterwards, the fixing bolt 27 is tightened to reach the torque required and contact between the bars of elements 20,20'and the plates of the block joint 21. By tightening bolt 27 as far at it will go, the flexible spacer 34 is compressed and flattened against the wall 26 of the block joint 21 as shown in Fig. 12. In this mode, the spacer is inside the side walls of the joined elements 20,20'without interfering any more with the latter so as to allow, as required, linear dilation of the system, Fixing as described above is reversible, simply by loosening the bolt and causing the pins to retract so as to separate the components which were engaged, and is repeatable in the same way every time it is needed.