ISOLATING BODY FOR COILS

Abstract: Isolating body (1) for coils, of the type used in the fabrication of reactances. It is formed by folding a flexible, isolating and rectangular sheet (2) along its transverse axis and by placing both coil heads, one on said folding axis wherein the sheet has two cuts (3) which define a minor width zone and the other head joining the opposite extremities. The sheet has also two folds (4, 5) on each side of the longitudinal axis, said folds forming two pairs of side wings which are closed onto the coil after winding the coil to the body. Each coil head (6, 7) has a pair of dovetail ribs (8) which are intended to fix the body to the mandrel during the winding.

Description: The field of the invention is that of insulating supports for coils, being of the type of coils that are preferably used to form part of reactors, whose core is defined by a series of E-shaped and I-shaped plates that are coupled together, in such a way that the central branch of the E-shaped plates is introduced in the hollow central part. The here disclosed insulating support is formed by the coil heads and a rectangular sheet-shaped plastic body, provided in the center and side with respective cuts, and being longitudinally formed to facilitate adaptation thereof to the coil heads. In order to facilitate the anchoring of the coil heads with regard to the support or mandrel where the winding is to take place, according to claim 1 the heads have in relation to the inside surface thereof, some projections that define an imaginary dovetail-shaped recess, in order to anchor the same in the support in order to avoid possible release. The here disclosed insulating support for coils has the purpose allowing configuration of the insulating element for coils, along with the pair of coil heads, in order to carry out winding on it, defining from the first turns an inseparable unitary assemble. FIELD OF APPLICATION The new insulating support for coils is preferably applicable in the configuration of generally rectangular-shaped coils, with their central part hollow, which are used in the manufacture of reactors that have a core of E-shaped and I-shaped plates that couple together. BACKGROUND OF THE INVENTION Among supports conventionally used for the manufacture of coils, FR-A-2246040 discloses a self-induction coil for discharge lamps including, as part of the invention, an insulating body for the coil. Said insulating body is a rectangular plan sheet-shaped body provided in the center with respective cuts and a pair of folding lines on both sides, nevertheless FR-A-2246040 does not include any element to prevent the insulating body from releasing during the process of winding, by fixing said insulating body on the mandrel where the coil is being wound. This feature would significantly improve the reliability of said process and therefore its efficiency. Another type of support for coils used in the manufacture of reactors, is formed by a plastic material body, obtained by injection, and which is defined by a rectangular profile with a U-shaped cross section, between whose wings the winding of the turns is carried out. Thus, the first manufacturing cost of coils is represented by the cost of the support made out of injected plastic. Another type of supports for coils used in the manufacture of reactors, is defined by a pair of coil heads, and a pair of independent insulating cardboard bodies, that are situated on both sides between the coil heads. In this case, given that in the materialization of the coil the pair of heads are independent elements in order to allow for carrying out the winding of the turns, all the elements forming the support must be fastened, because on the contrary their automatic release would be provoked, the coils can only be carried out one by one on independent supports and by means of so-called flyer type winders. In this way, production is very low and many winders are required, with the aggravating circumstance that the investment must be high and besides, the winding does not have suitable rigidity upon being done in a rounded manner, the turns not adapting adequately to the contour of the support. Likewise, the insulating cardboard parts must be fastened on themselves, so that the sides of the coil, remain adequately isolated and so that their assembly on the E-shaped plates of the core is made possible, thus avoiding a possible release of the same, said fastening being done by gluing. This is so, because the two insulating cardboard parts are totally independent from each other, as well as with regard to the coil heads, whereby the same could move laterally and even become totally released. DESCRIPTION OF THE INVENTION The present specification discloses an insulating support for coils as claimed in claim 1, preferably useful in the manufacture of reactors. The coils are formed from coil heads and a rectangular plan support, with its central part hollow and constituting the coil support basically by a generally rectangular plan sheet-shaped plastic body, provided laterally in the center with respective cuts that define a central narrower section, forming longitudinally and laterally respective pairs of formation lines that cause the bending of the sheet-like body according to two side wings. The sheet-shaped plastic body will be mounted in a first coil head by its narrower central part, with a certain mechanical stress, upon the projecting side wings resting on the inside surface of the coil head, causing the free end of the narrower sections to converge with each other, while it is perfectly fastened to the same, whereas the pair of side winds diverge from each other, facilitating the winding of the turns. Upon placing, the second coil head between the free ends of the folded sheet-shaped body, stress is created on said coil head which permits its configuration and assembly on the corresponding mandrel to accumulate a plurality of supports and to carry out the joint winding of all of them, with a single winder, which makes it possible to obtain high production. According to claim 1 the coil heads have, with respect to their opposite inside surfaces, respective pairs of ribs that form a dovetail-shaped recess, through which assembly thereof on the corresponding mandrel will be facilitated in order to avoid possible release. With the described structure, we obtain a perfectly reinforced support for coils and once the winding has been carried out, the coils are formed by means of a clamp that anchors them by one of their respective side wings, closing them on the winding, whilst upon placing the coil in the core of E-shaped plates, the opposite wings close upon the previously formed wings, materializing perfect isolation without the need of any additional operation. In order to complete the description that is going to be made hereinafter, and for the purpose of providing a better understanding of its characteristics, the present specification is accompanied by a set of drawings, in whose figures the most significant details of the invention described in this specification are represented in an illustrative and non-restrictive manner. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows a plan view of the plan sheet-shaped plastic body (2) that defines the body of the insulating support of the coil, it being possible to see its general rectangular shape, provided in the center and sides with respective cuts, as well as the conformation of the sheet-shaped body for suitable assembly thereof having been represented with dotted lines. Figure 2 shows a plan view of the already folded sheet (2') in such a way that the longitudinal side wings thereof are bent upwards according to two differentiated sections, facilitating the subsequent assembly thereof. Figure 3 shows a side view of the body of the previous figure, wherein one can see the way in which the pair of side sections of the folded sheet-shaped plastic body tend to bend upward. Figure 4 shows a perspective view of the sheet-shaped plastic body formed and folded over its narrower central section in order to materialize its assembly in the corresponding coil head. Figure 5 shows a perspective view of the sheet-shaped plastic body formed and assembled in the pair of coil heads, defining a stable body due to its own configuration that permits positioning thereof in a support or mandrel. DESCRIPTION OF A PREFERRED EMBODIMENT In view of the commented figures and in accordance with the numbering used, we can see how the support (1) for coils used preferably in the manufacture of reactors is fundamentally based on a sheet-shaped insulating plastic body (2, 2') and coil heads (6, 7), having a rectangular plan in the center and side of which respective cuts (3) that form a narrower central section, have been made, while longitudinally to the sheet-shaped body (2) a pair of respective folding lines (4) and (5) are made laterally. Upon forming the plastic sheet (2) in the described manner, respective pairs of longitudinal wings are defined laterally which open in the assembly of the sheet in the coil heads (6) and (7) facilitating the winding on the formed support. This is so, due to the fact that when the narrower central section of sheet (2, 2') is located in one of the coil heads (6), due to the configuration of the sheet (2, 2') the wider side areas tend to converge due to the effect of the mechanical stress formed between them, at the free end thereof, allowing placement of the coil head (7), while the open side surfaces of the box are formed laterally, just as one can see in figures (4) and (5); facilitating the winding of the turns. Thus, the folded sheet-shaped body (2') is mounted on the head (6) by its narrower central section, the folded wings resting on the side of the head, converging by the opposite end together, avoiding disassembly. The supports (1) thus formed are positioned in a support or mandrel, according to a specific number of them in order to pass to the simultaneous winding process of all of them, for which only one winder is necessary, resulting in a high and very profitable production. Besides, as the entire coil unit is perfectly reinforced, release of the sheet-shaped plastic body is prevented obtaining a totally reliable coil On the other hand, in order to facilitate insertion and fastening of the coil supports (6) and (7) in the corresponding mandrel, the coil heads define inside a pair of ribs (8) that form a dovetail-shaped recess through which the assembly in the support or mandrel is materialized, whereby release thereof is prevented. By means of the described configuration, a coil with the same characteristics as the conventional ones manufactured from an injected plastic support is obtained, in such a way that the coil will adapt better to the magnetic core, favoring the thermal dissipation and taking up less space in the window of the core, which will make it possible to make cores with a larger number of turns or with larger diameter copper wire when it is necessary to do so. Finally, once the coil has been made, the side wings will fold alternately, overlapping the wings of the corresponding sides, materializing a perfect electric isolation.

Claims: Insulating support for coils, the coils being of the type that are preferably used in the manufacture of reactors and that are formed from a generally rectangular-shaped support open in the center, the support (1) comprising at least one coil head (6, 7) and a folded sheet shaped body (2') obtained from a rectangular plan sheet (2), provided in the center and on the sides with respective cuts (3) and a pair of folding lines (4) and (5) on both sides that cause the bending thereof according to two side wings, characterized in that the folded sheet-shaped body (2') is mounted in at least one coil head (6,7) which has in relation to its opposite surface respective pairs of ribs (8) that form a dovetail-shaped recess for assembly thereof in the mandrel upon fitting in a body with a similar section. Insulating support for coils, according to claim 1, characterized in that the folded sheet-shaped body (2') is mounted in the coil head (6) by its narrower central part, the free ends of both wider side sections converging together. Insulating support for coils, according to claim 1, characterized in that the pair of wide wings diverge from each other, in such a way that as the configured and reinforced support (1) is located in a mandrel, its winding is facilitated.

Inventors: VILLARROYA LOMBAR CARLOS, VILLARROYA LOMBAR, CARLOS
Applicants: ESPECIALIDADES LUMINOTECN S A, ESPECIALIDADES LUMINOTECNICAS, S.A.
Application year: 1997
Main classification: H01F5
IPC codes: H01F5