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(11) | EP 1 557 915 A2 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Unit for shunting current from bus bars |
| (57) The invention concerns a unit for shunting current from bus bars which is made up
of a body divided internally into sections housing the blade shaped flexible electric
contacts (21) which can be flexed between an open and closed position of the conductor
elements of a bus bar. The electric contacts can be moved from one position to the
other by means of insulated wedges (23) associated with them and which can all be
moved axially simultaneously from the outside between a retracted open position and
a forward closed position by means of a thrust lever and interposed springs. |
Field of invention
[0001] This invention relates to the filed of the bus bar electric conductors, that is prefabricated elements for the formation of electric lines which elongate to carry and distribute electric energy, and concerns in particular a unit or device for shunting current from electric bus bars.
State of the technique
[0002] The type of bus bars taken into consideration in this case, usually include bar conductor elements insulated one from the other, positioned in parallel and housed in a profile or body having means for connecting to the other similar electric conductors and means for placing in position. In order to take-off current from said bus bars, at least along one part of their profile or body there are one or more recesses, and in line with each of them can be mounted a shunting unit or device which connects to the bus bar conductor elements.
[0003] A unit for shunting the current according to the known technique has, in a box shaped body, shunting contacts in the shape of flat pins or tongues, which insert between the conductor elements and to which can be connected the use or uses to be electrically powered. The shunting unit can be set up in connection with a switch and a safety fuse holder. The contact pins or tongues are pushed in and remain in contact with the conductor elements by means of flexible blade like springs which extend and act like a pincers against the face of each flat contact pin against the one which rests against the relative conductor element.
[0004] Such a current shunting unit however appears to be complex and costly and furthermore requires robust springs to maintain the active contact position and a significant coupling power of the unit with the bus bar elements.
Obiective and Summary of the Invention
[0005] The objective of this invention is to propose and provide a unit for shunting current which is easier to produce, more functional and reliable and where all the shunting contacts are movable from the outside by means of a single control element between the active and deactivated positions, the former closed on the conductor elements and the latter open, even with the bus bar live.
[0006] Such an objective is achieved, according to the invention, by using a unit for shunting current from the electric conductors with bus bar conductor elements, which is comprises a box shaped body closed at the top by a cover and having an extension at the bottom provided with recesses opening towards the bottom and required to receive said conductor elements, and wherein:
the body and relative bottom extension are subdivided internally into sections placed in parallel and alternating with the recesses of the bottom extension,
said sections house and hold flexible blade shaped electric contacts, extending along the sides of said recesses and movable by flexing between an open position, in which they are not touching the conductor elements and a closed position in which they are moved towards and placed in contact with said conductor elements,
said electric contacts are associated with wedges made of an insulating material, which move axially between a retracted inactive position, in which the electric contacts are in the open position, and an active forward position, in which the electric contacts are moved towards and placed in contact with said conductor elements, and
said wedges are associated with means of control for the simultaneous and parallel movement of the wedges between said inactive retracted position and said active forward position.
Brief Description of Drawings
[0007] The invention will however will become more evident in the continuation of this description made in reference to the enclosed indicative and not limiting drawings, in which:
Fig. 1 shows a partial exploded view of the components of the shunting unit;
Fig. 2 shows a view in perspective of the shunting unit as assembled;
Fig. 3 shows a front view of the shunting unit in Fig. 2;
Fig. 4 shows a side view;
Fig. 5 shows a view from above;
Fig. 6 shows a cross section according to the arrows A-A in Fig. 4;
Fig. 7 shows an enlarge view of a detail circled in Fig. 6
Fig. 8 shows a cross section according to the arrows B-B in Fig. 3;
Figs. 9, 10 and 11 show the connection of the shunting unit in the field of a output box and the coupling method with a bus bar.
Detailed Description of the Invention
[0008] As shown, the shunting unit or device 10 comprises a box shaped body 11, basically square, equipped at the top with a cover 12 and having an extension at the bottom 13, which is narrower and moreover dimensioned according to an output recess it is inserted in. This extension is formed by two facing primary rigid walls 14 integral with the body 11 and two facing secondary walls, 15, inserted and preferably flexible.
[0009] In the box shaped body 11 and in the relative bottom extension 13 are envisaged parallel partitions 16 which subdivide the inside into sections 17, which extend according to the height of the body 11 and on planes parallel with the inserted walls 15 on the two opposite sides of the bottom extension 13. In the two opposite rigid walls 14 of said bottom extension of the body there are formed recesses 18 opening downwards, placed between the sections 17, that is in line with the partitions, and dimensioned for each to receive a conductor element 19 of an electric bus bar 20. In the example illustrated there are five sections 17 and four recesses 18 between the sections, the same number of conductor elements 19 with which the shunting unit must couple.
[0010] On a level with the recesses 18, the sections 17 on the sides of the bottom extension are each delimited by the flexible wall 15 and by an adjacent partition 16 in the body. Furthermore, at least on a level with said recesses a crossways recess 16' has been shaped.
[0011] In said sections 17 are housed the electric contacts 21 which are flat shaped and flexible and envisaged to come into contact with the opposite faces of the conductor elements 19 of the bus bar 20 when these conductor elements are inserted into the recesses.
[0012] More precisely, in each of the intermediate sections 17 are assembled two electric contacts 21, whereas each of the lateral sections, that is those positioned towards the external, houses one single electric contact 21. The electric contacts 21 extend along the partitions 16 as far as the level of the recesses 18 for the conductor elements. Each electric contact 21 in its top section is attached to a partition adjacent to it, whereas its bottom section has a contact area 21' whose function is to rest against one side of a respective conductor element 19. Moreover, the electric contacts 21 are connected to terminals or shunt plates 22 to which the uses to be powered are connected by means of cables.
[0013] The electric contacts 21 flex between an open position, when they are not in contact with the conductor elements 19, and a closed position, when they approach and come into contact with said conductor elements. The electric contacts 21 can move from one position to the other by means of wedges 23 made of an insulating material.
[0014] As shown in particular in Fig. 6, the wedges 23 are placed between every a pairs of contacts and on the sides of the individual external contacts. They can be moved axially between a retracted inactive position, where the contacts 21 are in the open position, that is not in contact with the conductor elements 19, and an active forward position where the contacts are closed on the conductor elements. The wedges 23 can all move at the same time from one position to the other by means of a control lever 24 attached to the cover of the body by means of a fulcrum 25 and acting on the summits of the wedges through a cap or thrust rocker 26. The latter is supported by the control lever 24 by means of an oscillating axis 27 and engages each wedge 23 thanks to interposed pair of springs 28. The lever 24 can be controlled and moved on relative fulcrum 25 between an open position 1 and a closed position 2 of the contacts 21 thanks to a load screw 29 associated and engaging with a projecting part 30 attached to the body.
[0015] As shown in Figs. 9 - 11, on one hand the bus bar 20 can have an output recess normally closed by a sliding protection 31, on the other hand, the shunting unit 10 can be placed on an oscillating plate 32 inside an output box 33 together with other devices, such as a switch, fuse holder and a template 34 for opening the protection 31 of the output box. Therefore to connect the shunting unit or bulb to the bus bar 20 all is required is to approach and insert the contacts 21 between the conductor elements 19 of said bus bar when the wedges are retracted in the inactive position. Then, to maintain the connection, you use the load screw 29 so as to move the control lever 24 and at the same time the wedges from the open position 1 to the closed position 2. Thanks to the action of the wedges, the electric contacts 21 can easily be pushed and held in the closed position against the conductor elements of the bus bar using minimum force and advantageously also using lighter and less bulky springs.
said body and relative bottom extension are subdivided internally into sections (17) placed in parallel and alternating with the recesses (18) of said bottom extension,
said sections (17) house and hold flexible blade shaped electric contacts (21) running along the sides of said recesses (18) and flexing between an open position, in which they are not in contact with the conductor elements (19), and a closed position in which they are made to approach and come into contact with said conductor elements in said recesses,
said electric contacts (21) are associated with wedges (23) made of an insulating material and which move axially between a retracted inactive position, in which the electric contacts (21) are in the open position, and an active forward position, in which the electric contacts are made to approach and come into contact with the conductor elements, and
said wedges (23) are associated with means of control (24, 26, 28, 29) for the simultaneous and parallel movement of the wedges between said inactive retracted position and said active forward position.