Abstract:
This present invention refers to a combined terminal and casing for establishing electrical contact between a multi-wire cable and a magnetic wire that uses the insulation displacement connector (IDC) concept, wherein the terminal ( 11, 25 ) has holes ( 12, 26 ) and closed channels ( 13, 27 ) to receive the multi-wire cable ( 23, 36 ) and openings ( 14, 28 ) to receive the magnetic wire ( 24, 37 ) linked to narrow slots ( 15, 29 ). The casing ( 18, 31 ) has through-holes ( 20, 21, 32, 34 ) for inserting the multi-wire cable ( 23, 36 ) and the magnetic wire ( 24, 37 ), as well as an opening ( 19, 35 ) to receive the terminal. Inserting the terminal into the casing causes the pressure exerted on the multi-wire cable and the magnetic wire to force the entry thereof into the narrow channels, causing the isolation layer to be withdrawn, providing electrical contact between the multi-wire cable and the terminal, between the magnetic wire and the terminal and, consequently, between the multi-wire cable and the magnetic wire.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of the filing date under 35 U.S.C. §120 of International Patent Application No. PCT/BR2007/000154 filed Jun. 14, 2007, which claims the priority of Brazil Patent Application No. PI0602294-4 filed Jun. 14, 2006. 
     FIELD OF THE INVENTION 
     The present invention refers to interfaces providing electrical contact between magnetic wires and multi-wire isolated cables for use in electro-electronic equipment, such as universal engines and lamp reactors. 
     BACKGROUND OF THE ART 
     In order to function, electronic equipment generally needs electrical contact between wires and cables in order to propagate electrical power. 
     For example, engine windings, bobbins, transformers and power generators use metallic terminals to establish an electrical contact between two wires, enabling the propagation of electric power among the various wires and cables of which the device is comprised. 
     Currently, this contact can be obtained by way of metallic terminals that use crimp application. In this case, contact is achieved by way of a tube comprising projections and teeth. The projections perforate the isolation layer of the magnetic wire, causing the exposed conductor to be compressed towards the teeth, creating an electrical connection between the metallic tube and the magnetic wire. 
     However, in order to establish contact between magnetic wires and multi-wire cables, the latter must be pre-stripped. Additionally, said device has certain limitations, since the multi-wire cables must be placed in a specific position, which may hamper the correct positioning thereof. 
     Another disadvantage of terminals that use crimping technology arises from the fact that the pre-stripped wire and the terminal are deformed when high pressure is exerted thereon. This requires careful handling and constant monitoring of the terminal. 
     Isolation layer of a wire is understood to be both the plastic layer that incases copper wires and multi-wire cables, and the layer of varnish applied to magnetic wires, having the same purpose of isolating the internal conductor part from the outside world. 
     Another device currently used to establish contact between magnetic wires and multi-wire cables employs the isolation displacement connector (IDC) concept. According to this concept, the isolated wire is pressed into a slot designed to displace isolation and remove oxides through deformation in a given place of the plastic. 
     In this case, there is no need for prior stripping of the multi-wire cable, and two wires having the same diameter can be simultaneously placed in the same terminal. The metallic interface is free of contaminants, which renders the electrical contact stable. Moreover, there is no need to use large machines to establish contact. 
     The terminal of the prior art presents two openings to receive the multi-wire cable and the magnetic wire. However, the opening that receives the multi-wire cable has an open end. As the multi-wire cable and the isolating material to be removed are thick, a high mechanical tension is required to insert the cable into the opening. This strains the terminal, and may lead to a permanent deformation of the opening, consequently generating deficiencies in the electrical conductivity. 
     To reduce this undesirable effect, the terminal is made of a double-thickness premilled raw material, the larger thickness being designed to house the channel where the multi-wire cable will be connected. The use of this double-thickness premilled raw material results in increased production difficulty and higher costs for the end product. 
     Furthermore, the multi-wire cable is inserted in an opposite direction to the magnetic wire. Accordingly, two termination cycles are required to achieve electrical contact of the wires with the terminal. 
     Another embodiment of the prior art refers to a terminal having two sets of parallel channels, for use in applications that undergo vibration. In this case, one of the channels is slightly wider than the other, in order to absorb the vibration in the cable, preventing loss of electrical contact between the cable and the terminal, thus guaranteeing greater connection reliability. 
     Nevertheless, just like the simple contact terminal, the parallel channels that receive the multi-wire cable are open-ended. Thus, the terminal has the same disadvantages as those mentioned above, such as the increase of channel width owing to the high mechanical tension needed to remove the isolation layer of the cable at the open end, resulting in deficiencies in electrical conductivity. 
     SUMMARY OF THE INVENTION 
     The purpose of the present invention is to solve the problems of the prior art mentioned above, providing a combination comprised of two parts, the terminal itself and a casing to house the connection, using the channel concept (IDC). 
     The purpose of the present invention is to provide an efficient connection between cables and magnetic wires, where there is no loosening at the connection point that would cause a failure of the normal contact power. 
     Additionally, another purpose of the present invention is to provide a terminal with a single thickness in order to reduce production costs. 
     A further purpose of the combination for establishing electrical contact of the present invention is to provide a metallic terminal that allows contact between the magnetic wire and the isolated cable, without the need for crimping. The terminal has two channels for inserting the wires. The channel relating to the multi-wire cable is closed, which prevents loosening caused by stress, and failure in the normal connection power. Accordingly, the terminal does not need to be made of thick material, but can be entirely made of a thinner raw material, such as that used in the part destined for the magnetic wire. This feature means the product can be manufactured with a constant thickness, thus reducing the end cost. 
     Yet another purpose is to provide a combination for establishing electrical contact wherein the casing is designed to house the terminal and receive and position the multi-wire cable and the magnetic wire, besides isolating the contact in the terminal from the outside world. By inserting the terminal into the casing, certain points of the isolating material are cut, providing for electrical contact of the wire with the metallic terminal. This arrangement makes the application of both the cable and the wire occur simultaneously, in one cycle alone, since both are inserted into the respective channels in the same direction. 
     The purposes of the present invention are achieved by providing a terminal and casing combination for electrical contact, comprising a contact interface terminal between a magnetic wire and a multi-wire isolated cable and a casing to receive the terminal, the magnetic wire and the multi-wire cable, wherein the terminal is formed by a single material having constant thickness. The terminal has a hole for inserting the multi-wire cable, a closed channel linked to said hole and having a smaller diameter than said hole, an opening to receive the magnetic wire and a slot linked to said opening, having a smaller diameter than the respective opening. The casing has an opening in its upper part to receive the terminal and through-holes to receive the multi-wire cable and the magnetic wire. 
     Additionally, a terminal and casing combination for electrical contact is provided, comprising a contact interface terminal between a magnetic wire and a multi-wire isolated cable and a casing to receive the terminal, the magnetic wire and the multi-wire cable. The terminal is formed by a single material having constant thickness, and has at least two parallel holes for inserting the multi-wire cable, at least two parallel closed channels linked to said holes and having a smaller diameter than said holes, at least two parallel openings to receive the magnetic wire, and two parallel slots linked to said openings, having a smaller diameter than the respective openings. Additionally, one of the closed channels is slightly larger than the other parallel channel. Alternatively, one of the parallel slots may also optionally be slightly wider than the other slot. 
     The channels relating to the multi-wire cable are closed, preventing wear and tear caused by inserting the thick cables and constant pressure exerted thereon. Moreover, a thinner raw material can be used in the entire terminal. 
     In the same way, the casing has an opening to receive the terminal and respective openings for inserting and positioning the multi-wire cable and the magnetic wire, serving to isolate the contact from the outside world. The two cables are inserted in the same direction and, therefore, in a single cycle. The cut at certain points of the isolating material causes electrical contact of the wire with the metallic terminal. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of the terminal of the prior art in a first embodiment. 
         FIG. 2  is a perspective view of the terminal of the prior art in a second embodiment. 
         FIG. 3  is a front view of the terminal of the present invention in a first embodiment. 
         FIG. 4  is a side view of the terminal of the present invention in a first embodiment. 
         FIG. 5  is a perspective view of the terminal of the present invention in a first embodiment. 
         FIG. 6  is a front view of the casing of the present invention in a first embodiment. 
         FIG. 7  is a side view of the casing of the present invention in a first embodiment. 
         FIG. 8  is a perspective view of the casing of the present invention in a first embodiment. 
         FIG. 9  is an exploded view of the combination comprising the terminal and the casing of the present invention in a first embodiment, showing the correct insert position of the multi-wire cable and the magnetic wire in the combination. 
         FIG. 10  is a perspective view illustrating the partial insert of the multi-wire cable and the magnetic wire in the terminal and in the casing in a first embodiment. 
         FIG. 11  is a perspective view of the final position of the combination in a first embodiment, with the multi-wire cable and the magnetic wire inserted therein. 
         FIG. 12  is a perspective view of the terminal of the present invention in a second embodiment. 
         FIG. 13  is another perspective view of the terminal of the present invention in a second embodiment. 
         FIG. 14  is a front view of the terminal of the present invention in a second embodiment. 
         FIG. 15  is a side view of the terminal of the present invention in a second embodiment. 
         FIG. 16  is a perspective view of the casing of the present invention in a second embodiment. 
         FIG. 17  is an upper view of the casing of the present invention in a second embodiment. 
         FIG. 18  is a front view of the casing of the present invention in a second embodiment. 
         FIG. 19  is a side view of the casing of the present invention in a second embodiment. 
         FIG. 20  is an exploded view of the combination comprising the terminal and the casing of the present invention in a second embodiment, showing the correct insert position of the multi-wire cable and the magnetic wire in the combination. 
         FIG. 21  is a perspective view illustrating the partial insert of the multi-wire cable and the magnetic wire in the terminal and in the casing in a second embodiment. 
         FIG. 22  is a perspective view of the final position of the combination in a second embodiment, with the multi-wire cable and the magnetic wire inserted therein. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  illustrates a terminal of the prior art, which employs the channel concept (IDC). As can be seen, the terminal  1  comprises two parts  2  and  5 , having different thicknesses. The first part  2  comprises an opening  3  to receive the multi-wire cable and a channel  4 , whereas the second part  5  comprises an opening  6  to receive the magnetic wire and a slot  7 , having a smaller diameter than the channel  4 . As the cables are inserted into their respective openings, the pressure exerted forces the cable into a channel having a smaller diameter than the wire itself, dislodging the film that envelops the wires (plastic or varnish), thus removing the isolation at certain points and providing direct contact of the wire with the terminal. 
     Since the terminal is made of metal, and, therefore, conducts power, electrical contact between the magnetic wire and the multi-wire cable is established. 
     The arrows in  FIG. 1  indicate that the multi-wire cable and the magnetic wire are inserted into their respective openings in opposite directions, meaning two termination cycles are required to establish electrical contact of the wires with the terminal. 
       FIG. 2  is a second embodiment of the metallic terminal of the prior art. In this terminal  8 , two openings  9  and two channels  10  to receive the multi-wire cable are arranged parallel, wherein one of the channels is slightly wider than the other. The purpose of this difference in width is to absorb vibrations as may occur in the equipment wherein it is installed, preventing vibration from interfering at the point of electrical contact of the terminal. 
       FIGS. 3 to 11  present the terminal and casing combination of the present invention in a first embodiment. 
     As can be seen in  FIGS. 3 ,  4  and  5  of the drawings, the terminal  11  of the present invention comprises a hole  12  for inserting the multi-wire cable and a closed channel  13  linked to said hole  12 . 
     Additionally, the terminal has an opening  14  linked to a slot  15  for inserting the magnetic wire. 
     In order to avoid displacement of the terminal inside the casing, which could compromise the electrical contact, said terminal has projections  16  to be fitted into the casing. Said projections serve as an anchor for the terminal in the casing, acting by interference. Inserting the terminal in the casing will cause the projections to drive into the plastic part of the casing. Additionally, the terminal optionally has flaps  17  to be fitted into the casing, avoiding movement that might compromise the electrical contact. 
       FIGS. 6 ,  7  and  8  present an arrangement of the casing  18  of the present invention. The casing has a rectangular arrangement, comprising an opening  19  in its upper part, to receive the terminal, first and second through-holes  20  and  21  and optional windows  22 . 
     The first through-hole  20  is designed to receive the multi-wire cable and therefore has a smaller diameter than the second through-hole  21 , designed to receive the magnetic wire. 
     The purpose of the windows  22  is to receive said terminal flaps  17 , in order to fit the terminal into the casing  18 , preventing potential displacement. 
       FIGS. 9 ,  10  and  11  present successive views of how the multi-wire cable and the magnetic wire are inserted into the combination. 
       FIG. 9  is an exploded view of the terminal  11  and casing  18  combination, indicating the correct position for inserting the multi-wire cable  23  and the magnetic wire  24 . 
       FIG. 10  shows the correct insert position the components, with the terminal  11  being inserted into the opening  19  in the upper part of the casing  18 , the multi-wire cable  23  being inserted into the smaller-diameter hole  20  of the casing  18  and the magnetic wire  24  being inserted into the hole having a smaller diameter  21 . 
     The combination is operated as follows. The terminal should be inserted into the casing until its hole  12  (see  FIG. 3 ) reaches the same position as the smaller-diameter hole  20  (see  FIG. 6 ) of the casing. In this position, there is also an opening to receive the magnetic wire  14  of the terminal aligned with the smaller hole  21  of the casing. 
     At this point, the multi-wire cable  23  and the magnetic wire  24  should be inserted into the combination in their respective positions, up to the point at which it is desirable to withdraw the isolation layer. This arrangement of the components is presented in  FIG. 10 . 
       FIG. 11  presents the final arrangement of the combination. Since the terminal channel  13  is narrower than its hole  12 , the multi-wire cable is forced into the channel  13  when the terminal is completely inserted into the casing. This forced passage through the narrower channel will cause minor cuts in the cable&#39;s isolation layer. Since the channel is closed, the insertion of the terminal into the casing will establish a direct and efficient contact between the multi-wire cable and the metallic terminal. 
     The process is similar for the magnetic wire. By inserting the terminal into the casing, the magnetic wire  24  is forced inside the slot  15 , the isolation and the layer of varnish that protect the wire are withdrawn at certain points, and a direct contact between the wire and the terminal is established. 
     Therefore,  FIG. 11  presents the final position of the terminal and casing combination, with the electrical contact already established between the multi-wire cable and the magnetic wire. 
       FIGS. 12 to 22  present the terminal and casing combination of the present invention in a second embodiment, to be used in applications subject to vibration. 
     As can be seen in  FIGS. 12 to 15 , the terminal  25  of the present embodiment presents two combinations for connecting the multi-wire cable and the magnetic wire. At least two parallel holes  26  are provided for insertion of the multi-wire cable linked to at least two parallel closed channels  27 . Additionally, the terminal has at least two parallel openings  28  linked to at least two parallel slots  29  for inserting the magnetic wire. 
     Additionally, the terminal has projections  30  and optional flaps (not shown) for insert into the casing. 
     In order to absorb vibrations that may impact the combination, one of the parallel channels  27  that receive the multi-wire cable is slightly wider than the other parallel channel. The purpose of the wider channel is to provide support for the conductor without necessarily deforming it. Since a deformation of the conductor occurs in the narrower channel by virtue of the displacement of the isolating material, the mechanical contact becomes weak at this point, meaning the vibration may compromise the contact. Therefore, the main reason why one of the parallel channels is wider is to prevent movement of the conductor in the narrower channel when the combination is submitted to vibrations, guaranteeing a more reliable connection. 
     Alternatively, one of the parallel slots  29  designed to receive the magnetic wire may also optionally be wider than the other, in order to absorb the vibration better and to provide a mechanically more efficient connection. 
       FIGS. 16 to 19  present an arrangement of the casing  31  of a second embodiment of the present invention. 
     As can be seen in the figures, the casing  31  has parallel through-holes  32  to receive the multi-wire cable, parallel openings  33  to receive the magnetic wire, linked to parallel slots  34 . Furthermore, there is an opening  35  in an upper part of the casing to receive the terminal, and optional windows (not shown) to fasten the terminal. 
       FIGS. 20 to 22  present successive views of the insert of the multi-wire cable  36  and the magnetic wire  37  into the terminal and casing combination. 
     Similarly to the insert carried out in the first embodiment of the present invention, the multi-wire cable  36  and the magnetic wire  37  must be correctly positioned in the casing, jointly with the terminal  25 , as illustrated in  FIG. 20 . 
     The multi-wire cable  36  and the magnetic wire  37  should then be inserted into the terminal  25  up to the point where contact is desired. With the subsequent full insertion of the terminal  25  into the casing  31 , the isolating material will be displaced at a point of the multi-wire cable  36  and the magnetic wire  37  and consequently contact with the terminal will be achieved. When the terminal is fully inserted into the casing, the terminal  25  projections  30  will be driven into the plastic of the casing, fastening the terminal to the casing. 
     It is important to note that the multi-wire cable and the magnetic wire are inserted into the terminal and casing combination in the same direction, as indicated by the arrows in  FIG. 10 , enabling the respective contacts between the multi-wire cable and the terminal, and between the magnetic wire and the terminal, to occur simultaneously. Thus, just a single cycle is required to establish electrical contact between the multi-wire cable and the magnetic wire, saving assembly time for the combination. 
     Moreover, this application can be carried out by using simple manual tools for equipment maintenance and when production is not large-scale. 
     Additionally, the fact that the channel designed to receive the multi-wire cable is closed, results in less loosening in the region of contact of the terminal, providing more efficient electrical conductivity. Accordingly, there is no need to make this channel with a thick material. Therefore, the terminal can be made with a constant thickness, resulting in lower manufacturing costs. 
     Although the above description refers to preferred embodiments, persons skilled in the art should understand that the present invention is not limited to the details set forth in the teachings above. 
     It is important to note that variations, changes and amendments of the invention described herein are possible for persons skilled in the art, without straying from the spirit and scope of the present invention or equivalents thereof, encompassed within the claims appended hereto and their equivalents.