EP0033943A1 - Bobbin for electrical coils - Google Patents

Abstract

Coil bodies for electrical coils with a coil body flange (1) with straight wire guide slots (3) rounded at the transition to the coil body winding space (3) with contact pin connections (4), the wire guide slots (3) on the contact pin connection side being at least partially expanded and each having a coil body flange boundary as a wire catch (5) is formed.

Description

The invention relates to a coil former for electrical coils with a coil former flange with wire guide slots and pin connections.

The known, commercially available coil formers with pin connections, i.e. the so-called pin bobbins for RM and R cores can only be wound on manual winding machines or semi-automatic machines without great difficulty. Devices of this design naturally work only slowly and therefore uneconomically.

When processing, i.e. Winding these known bobbins on fully automatic winding devices arise considerable manufacturing difficulties. Due to the partially curved wire guide slots of the pin flanges of these bobbins in connection with a missing radius at the transition from the wire guide slot to the winding space of the bobbin, a wire break is noticeable again and again when winding thin wires, the diameter of which is less than 0.07 mm. In addition, crossovers of the winding wires on the pin connection side of the wire guide slots cannot always be avoided. These wire crossings are short-circuited during the soldering process and thus lead to coil failure. Especially with fully wound bobbins, the radii and the entire design of the inlet of the wire guide slots repeatedly lead to the winding wires slipping off and thus to considerable manufacturing difficulties. All this stands in the way of processing these known bobbins on fully automatic winding devices.

By redesigning the coil body flange of this RM or R coil body equipped with the contact pin connections, the above-mentioned difficulties occurring in the previous fully automatic production can be largely eliminated. The curved wire guide slots have a straight course and are rounded at the transition from the wire guide slot to the coil former winding space. These are known exemplary embodiments, some of which are already being used with similar bobbins. These two. Measures significantly reduce the number of wire breaks that have repeatedly occurred when processing thin wires.

The present invention has for its object to provide a bobbin of the type mentioned, which all the disadvantages of the known bobbin mentioned above are not inherent and consequently. is fully automatic.

To achieve this object, the invention provides for a bobbin for electrical coils with a bobbin flange with straight and rounded at the transition to the bobbin winding space wire guide slots with contact pin connections that the wire guide slots on the contact pin connection side are at least partially expanded, in particular conically expanded, and each one Coil body flange is designed as a wire catch, ie the coil body flange is nose-shaped in its web-like part leading to the wire guide slot entrance.

This widening of the wire guide slots moves the partially unavoidable crossing points of the winding wires from the endangered soldering zone into the slots in the coil body flanges. In this way, short circuits that occur again and again when soldering the contact points of the previous coil former can be avoided.

This widening of the wire guide slots also brings advantages in coil formers, since this change makes deburring of the e.g. thermosetting plastic parts made possible by a blasting process.

The dimensions of the wire catch tabs expediently remain within the intended installation dimensions of the respective coil size, which is why these coils do not require a larger base area on the printed circuit board. With these wire catch tabs, the winding wires are forcibly guided into the corresponding wire guide slots of the coil form, especially in the case of fully wound coils. It is therefore no longer possible for the winding wires to slide off, as occurs repeatedly in the former bobbins.

• Fig. 1 eine Unteransicht auf einen Spulenkörper nach der Erfindung in teilweise gebrochener Darstellung und in vergrößertem Maßstab,
• Fig. 2 einen Schnitt gemäß der Linie II-II in Fig. 1.

The invention is explained in more detail below using an exemplary embodiment. It shows:

• 1 is a bottom view of a bobbin according to the invention in a partially broken view and on an enlarged scale,
• 2 shows a section along the line II-II in FIG. 1st

On one coil former flange 1 of a coil former, for example for RM and R cores, webs 2 are integrally formed. These webs serve as carriers for contact pin connections 4 and are formed with straight wire guide slots 3. The wire guide slots 3 are chamfered on their part facing the contact pin connection side (see the hatched areas 6). As shown in FIG. 2, the contact pin connections 4 are embedded in the webs 2, preferably cast in. The web part 5 acts due to its special, ie nose-like shape as a wire catch. This wire catch ensures that the winding wires are forced into the wire guide slot 3. At the transition from the wire guide slots 3 to the winding space of the coil former, the wire guide slots are rounded, as indicated at 7, 8.

Claims (2)

1. Coil bobbin for electrical coils with a bobbin flange with straight and rounded at the transition to the bobbin winding space wire guide slots with contact pin connections, characterized in that the wire guide slots on the contact pin connection side are at least partially expanded and their respective bobbin flange is designed as a wire catch. 2. Bobbin according to claim 1, characterized in that the wire guide slots are flared.

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