INSULATING BOARD BETWEEN A WINDING AND A CORE SHEET PACK AND BALLAST OR TRANSFORMER PROVIDED WITH SAID INSULATING BOARD

Abstract: The invention relates to an insulating board (11) be­ tween the winding and core sheet pack of a ballast or transformer, said board being intended to be placed be­ tween the inner gable surface (4) of a winding loop (2) and the gable of a core sheet pack extending through the winding loop opening (5). The insulating board is provided with hinge members (13) to carry outer side flaps (12), whose free ends are fitted with catching claws (15) which can be brought into engagement with counter-catch means (14) mounted on the insulating board. Mounted in its position, said insulating board, together with its outer side flaps, surrounds the end sections of surface insulations (3) and holds said surface insula­ tions fixed in position without requiring the use of binding tapes.

Description: The invention concerns the combination of a ballast or a transformer having a winding and a core sheet pack and an insulating board assembly, the insulating board assembly comprising an insulating board between the inner surface of the end face of a winding loop of the winding and the end face of the core sheet pack extending through the winding loop opening. One problem in manufacturing ballasts or transformers is the fastening of separate surface insulations surrounding the winding by means of binding tapes. The fastening of binding tapes is hitherto performed through manual labour which causes and requires labourious and monotonous, slow and expensive work which cannot be automated with reasonable arrangements. Another problem in manufacturing ballasts or transformers is the swelling of a winding as a result of the movement of the winding threads. This may complicate the fitting of a winding in a core sheet pack, unless the winding windows are dimensioned with sufficiently great tolerances. It is the object of the present invention to eliminate the above mentioned problems by using a specially designed insulating board between the winding and the core sheet pack. In order to meet this object the invention proposes that said insulating board carries, by way of hinge members, outer side flaps whose free ends are provided with catch means which can be brought into engagement either with each other or with counter-catch means at the corresponding end of the insulating board, whereby, with the outer side flaps turned into a position, in which the catch means are in engagement with each other, the take-up openings for the winding will be formed between the edges of the insulating board and the outer side flaps. It is known to form the winding and thus the winding loop opening of a ballast or transformer in a rectangular shape when seen in the direction of the winding axis and to surround the longer side runs of the winding with separate surface insulatings. According to a further feature of the invention the insulating board assembly comprising the insulating board, the hinge member and the outer side flaps surrounds the end sections of the surface insulations. According to a further embodiment of the invention one of the outer side flaps of the insulating board assembly is provided with clamping pins or with a groove for receiving a clamping rib. A particularly appropriate embodiment of the invention will now be described with reference made to the accompanying drawing, in which Fig. 1 is a plan view of a ballast winding, whose end faces are fitted with insulating boards of the invention shown in cross-section, Fig. 2 is a side view of an insulating board assembly of the invention, and Fig. 3 is a cross-sectional view of a winding into which an insulating board shown in Fig. 2 can be inserted in the direction of an arrow I. Fig. 1 shows a ballast winding 2 which is rectangular, as seen in the direction of the winding axis. A not shown ballast core sheet pack extends through a winding loop opening 5 and also on the outer faces of winding side runs 6. For insulating the winding 2 from the core sheet pack, its longer side runs 6 are surrounded with separate surface insulations 3. An insulating board 11 is fitted between the inner surface 4 of the winding end faces 7 and the core sheet pack extending through opening 5. The insulating board 11 carries, by way of hinge members 13, outer side flaps 12 whose free ends are provided with catch means 15 that can be brought into engagement with counter-catch means 14 at the corresponding ends of the insulating board 11. Alternatively, the catch means 15 or the ends 12a can be made so long that said catch means 15 engage with each other. Then, however, the outer side flaps 12 must be bent further aside, so that the insulating board assembly, designed generally by reference numeral 1, can be fitted in position around winding 2. Preferably, this is done immediately after the winding has been wound with the surface insulations 3 fitted in position. Thus, the insulating board 11, together with its outer side flaps 12, prevents the swelling of a winding and, at the same time, fastens the surface insulations 3 upon the winding. The gap between the insulating board 11 and the outer side flaps 12 is dimensioned so as to serve against swelling when the catch means 14 and 15 are engaged with each other. One of the outer side flaps 12 can be provided with winding thread clamping pins or with a groove receiving a clamping rib, the fastening of winding thread outlets being resolved at the same time.

Claims: The combination of a ballast or a transformer having a winding (2) and a core sheet pack and an insulating board assembly (1), the insulating board assembly (1) comprising an insulating board (11) between the inner surface (4) of the end face of a winding loop of the winding (2) and the end face of the core sheet pack extending through the winding loop opening (5), whereby the insulating board (11) carries, by way of hinge members (13), outer side flaps (12) whose free ends (12a) are provided with catch means which can be brought into engagement either with each other or with counter-catch means (14) at the corresponding end of the insulating board (11) whereby, with the outer side flaps (12) turned into a position, in which the catch means (14, 15) are in engagement with each other, the take-up openings for the winding (2) will be formed between the edges of the insulating board (11) and the outer side flaps (12). The combination according to claim 1, wherein the winding loop opening (5) is rectangular when seen in the direction of the winding axis and wherein the longer side runs (6) of the winding (2) are surrounded with separate surface insulations (3), the end sections of the surface insulations (3) being surrounded by the insulating board (11), the hinge members (13) and the outer side flaps (12). The combination according to claim 2, wherein one of the outer side flaps (12) of the insulating board assembly (1) is provided with clamping pins or with a groove for receiving a clamping rib.

Inventors: PERTTI, LILJA
Applicants: OY HELVAR
Application year: 1987
Main classification: H01F27
IPC codes: H01F27