GB2209627A

GB2209627A - Coil for electromagnetic actuator

Info

Publication number: GB2209627A
Application number: GB8716606A
Authority: GB
Inventors: Hugo Schrott
Original assignee: Aweco Kunstofftechnik & C GmbH
Current assignee: Aweco Kunstofftechnik & C GmbH
Priority date: 1987-07-15
Filing date: 1987-07-15
Publication date: 1989-05-17
Also published as: GB8716606D0

Abstract

In order to simplify the manufacture of the coil and to facilitate the connection of the electric leads, the coil has an end plate of its insulating core formed with a straight edge, and contacts 13 extending over both surfaces of the straight edge to form a flat contact plate 5 for connection to an edge connector 22. The contacts 13 can be metal strips which are bent in a U-shape, grip around the edge of the plate 5 and have retaining fingers (21, Figs 1, 4) for the wire ends to be soldered on. <IMAGE>

Description

MAGNET COIL WITH PLUG-IN CONNECTION Description: The invention relates to a magnet coil with a plugin connection, having a coil body of insulating material which has a tubular centre section and two end plates, and having a winding, with one of the end plates having a connecting part with a rectilinear edge, on which connecting part two metal, flat plug-in members are arranged which are electrically connected to the wire ends of the winding, and with the wire ends and the locations where they are joined to the plug-in members being covered by an insulating coating. Magnet coils of this type are manufactured in exceptionally large numbers and, completed as electromagnets, are preferably fitted in dishwashers and washing machines. There, for example, they are used for actuating dosaging devices for washing agents, for valve actuation, etc.

A magnet coil of the type described is known from US Patent Specification 4,236,131 Flat apertures are formed into the edge of the connecting part of the coil body, which apertures start at the edge and extend parallel to the surface of the end plate and into the latter. Two contact blades of brass sheet are inserted as plug-in members into these apertures. They are securely held in the coil body with claws which during insertion open out as a result of a wedgelike inner shape of the apertures.

The connecting lines of the exciting winding with flat receptacles are connected to these contact blades projecting beyond the edge.

This known magnet coil is manufactured as follows: first of all the start of the wire, at a notched point (neck), is looped around one of the two contact blades; winding then follows at a high rotational speed and finally the wire end is looped around the other contact blade. The looping points are then soldered. Finally the entire coil is encapsulated in plastic which joins with the basic coil body and encloses, seats and insulates the winding and also the connections of the winding wire at the contact blades. Only the end sections of the contact blades, insofar as they are needed asptug-;n members, protrude beyond the plastic body.

The arrangement described for connecting the leads to the magnet coils is now no longer satisfactory in several respects. The flat receptacles, which can only be secured with difficulty, must be pushed on individually by hand. They are relatively long and normally have no insulating sheeting, so that a lot of space has to be provided in the connecting area. Depending on the proportions by volume in the individual application, various forms of straight, angled or offset contact blades are therefore in use. Soldering the winding ends to the contact blades by means of a soldering iro takes a relatively long time.

All this makes mass production of such magnet coils difficult.

The object of the invention is to simplify and speed up the fully automatic manufacture of magnet coils and also to create the conditions enabling the coils, completed as electromagnets, to be fitted at the user's fully automatically into the machines for which they are intended and to be provided with line connections.

Based on a magnet coil of the type described by way of introduction, this object is achieved according to the invention in that the connecting part is made as a flat plug-in plate for an edge connector to be pushed on, and that the plug-in members are contact laminae which, on both sides of the plug-in plate, which sides are opposite one another, form congruously arranged, strip-shaped metal contact faces extending at right angles to the edge.

On the one hand, this results in advantages in the fully automatic manufacture of the magnet coils and, on the other hand, advantages in assembly owing to the use of so-called edge connectors. These contain forked springs and have hitherto been known for connecting lines to printed circuit boards. In the product specifications of AMP Deutschland GmbH, AMPrestrasse 7 - 11, D-6070 Langen, near Frankfurt/Main, the abovementioned connectors are designated as an MT card edge connector. They have a cutting clamping joint for the insulated connecting conductors and a relatively small block-shaped insulating-material housing so that they do not require much installation space. Above all, however, these edge connectors can be automatically manipulated by means of production robots.

An essential design feature of the connecting part is that it has a platelike area in which flat metal members, so-called contact laminae, are embedded flush with the surface. A preferred embodiment is that the contact laminae are metal strips which are bent in a U-shape and grip around the edge of the plug-in plate. Located betueen the contact laminae is a windowlike aperture in the plugin plate into which a locking dog of the edge connector can engage.

It is also proposed that the wire ends of the winding be looped around retaining fingers of the contact laminae. In this case, the winding ends can be joined to the contact laminae by dip soldering. A preferred type of embodiment of the invention is based on contact laminae in the form of metal strips. On both ends, these contact laminae have lugs protruding at right angles, from which tag strips protrude which run parallel to the contact laminae. The lugs and tag strips placed congruously on top of one another are inserted into recesses in the coil body and are securely held by means of a locking device, with the tag strips partly protruding and acting as retaining fingers. Advantageous is the low weight of such metal connecting parts and a perfect mounting on the coil body, so that the winding can be applied at a very high rotational speed.

Another, likewise advantageous possibility of joining the ends of the winding wires to the contact laminae consists in the wire ends being looped around retaining fingers arranged on the coil body and being welded or soldered pointlike to the contact laminae.

Exemplary embodiments of the invention are described below with reference to the drawing, in which, in particular: Figure 1 shows the end view of a magnet coil with inserted contact laminae before winding and before encapsulation, Figure 2 shows a longitudinal section II-II of the magnet coil according to Figure 1, Figure 3 shows one of the two stamped parts which form the contact laminae and their retaining fingers, Figure 4 shows a plan view of the connecting part of the magnet coil according to Figure 1, Figure 5 shows a three-dimensional representation of the finished magnet coil and the edge connector, by means of which the leads are connected, and Figure 6 shows the schematic representation of another embodiment of a magnet coil.

The coil body, in its original configuration according to Figures 1, 2 and 4, at one end face of its hollowcylindrical centre part (1), has a circular-disc-shaped end plate (2) and, at the other end, a thicker end plate (3) which is roughly in the shape of a shield. The upper edge of this end plate (3), because of its special design, is prepared for accommodating two stamped parts (4) of thin, tin-plated brass sheet, the blank of which is shown by Figure 3. The end plate (3) has a centre projection, which forms a so-called plug-in plate (5), and two outer projections (6). The plug-in plate (5) is subdivided into three strip-shaped areas running in parallel, with the outer area (7) being slightly shorter and of smaller thickness than the centre area (8) which has a continuous window aperture (9). The outer projections (6), at the inner sides facing toward one another, each have an approximately semi-circular longitudinal groove (10) which is indicated by a broken line in Figure 1 and is shown in Figure 4. Between the plug-in plate (5) and the projec tions (6), the edge of the end plate (3) is further indented, and here sits in each case one locking finger (11) which has a catch tooth (12).

The stamped part (4) is subdivided into a stripshaped contact lamina (13), two lugs (14) sitting at right angles against both ends of the same, and two tag strips (15) which protrude from the lugs (14), extend parallel to the contact lamina (13), face towards one another and are arched in a groove shape in cross-section. The lugs (14) are offset with respect to the contact lamina (13).

The sloping areas (16) of the offset portion can also be recognized in Figure 4.

Before the stamped parts (4) are used further, their contact lamina (13) is bent through 1800 in the centre so that the lugs (14) and the tag strips (15) come to rest on one another. The contact lamina (13) therefore has a U-shape, which can be recognized from Figure 2. As Figure 4 shows, the tag strips are arched such that they produce, joined together in pairs, a hollow, tubelike retaining finger (21). The stamped part (4) formed in this manner, with the U-bend of the contact lamina (13), is pushed onto the outer area (7) of the plug-in plate (5), with at the same time the retaining fingers (21) being half accommodated by the longitudinal grooves (10) of the projections (6). The lugs (14) are thereby held such that they directly rest on one another.This double lug, when being pushed in, slides past the catch tooth (12), partly as a result of its own elastic deflection and partly by the locking finger (11) being thrust aside, until the catch tooth (12) finally snaps in over the upper edge of the double lug (14) and thereby secures the stamped part (4) as a whole against withdrawal. Figures 1, 2 and 4 show the two stamped parts (4), arranged in mirror image, in the inserted final position, with the contact lamina (13) of the left-hand stamped part partly being in broken section in Figures 1 and 4.

The start of the winding wire for the coil can be looped around the upper end of the left-hand retaining finger (21) according to Figure 1. In a groove (17), which is only apparent from Figure 4, the wire is then guided along the edge of the end plate (3). This groove finally leads tangentially into the inner space of the coil. Once the coil has been fully wound in the direction of the arrow (Fig. 1), the wire is collected between two projections (18) at the edge of the end plate (3) and guided up through a further groove (19) (Fig. 4) to the right-hand retaining finger. The winding-wire ends are finally soldered to the retaining fingers by dipping the retaining fingers (21) into a soldering bath.

The coil, together with the winding, is now encapsulated in plastic, with it receiving the outer shape shown in Figure 5 and indicated by chain-dotted outlines in Figures 1 and 2. The winding is covered by a cylindrical plastic coating. Projections (20) surround the retaining fingers (21) and the locking fingers (11). Located between the projections (20) is the plug-in plate (5) which is overlaid with the contact laminae (13) and is suitable for an edge connector (22) to be pushed on which is joined in turn to a two-core connecting line (23).

The fact that this pLug-in plate (5), with respect to the rectilinear outlines extended between the heads of the projections (20), is set back and does not jut out, essentially enables the edge connector (22) to be pushed on automatically by means of an assembly robot.

Another embodiment of a connecting part is indicated in Figure 6. The strip-shaped contact laminae (25 and 26) used here, which are likewise laid over the edge of a platelike part, engage in hooked manner with their ends into recesses (27) of the coil body. The left-hand contact lamina (25) is drawn down further on the rear side and the right-hand contact lamina (26) is drawn down further on the visible front side. The winding-wire ends are connected here in such a way that the winding wire (28) is first of all guided from a pin (29) over the right-hand contact lamina (26) to a left-hand pin (30) of the coil body; it is then wound on and is finally extended in appropriate manner between two pins on the rear side over the contact lamina (25). At pointlike welding locations (31), the extended wire pieces can now be joined to the two contact I ami nae.

DRAWING REFERENCES 1 CENTRE PART 2 END PLATE 3 END PLATE 4 STAMPED PART 5 PLUG-IN PLATE 6 OUTER PROJECTIONS 7 OUTER AREA 8 CENTRE AREA 9 WINDOW APERTURE 10 LONG GROOVE 11 LOCKING FINGER 12 CATH TOOTH 13 CONTACT LAMINA 14 LUGS 15 TAG STRIPS 16 SLOPING AREA 17 GROOVE 18 PROJECTION 19 GROOVE 20 PROJECTION 21 RETAINING FINGERS 22 EDGE CONNECTOR 23 CONNECTING LINE 24 25 CONTACT LAMINA 26 CONTACT LAMINA 27 RECESS 28 WIRE ENDS 29 PIN 30 PIN 31 WELD LOCATION

Claims

Claims: 1. Magnet coil with a plug-in connection, having a coil body of insuLating material which has a tubular centre section and two end plates, and having a winding, with one of the end plates having a connecting part with a rectilinear edge, on which connecting part two metal, flat plug-in members are arranged which are electrically connected to the wire ends of the winding, and with the wire ends and the locations where they are joined to the plug-in members being covered by an insulating coating, characterized in that the connecting part is made as a flat plug-in plate (5) for an edge connector (22) to be pushed on, and that the plug-in members are contact laminae (13; 25, 26) which, on both sides of the plug-in plate (5), which sides are opposite one another, form congruously arranged, strip-shaped metal contact faces extending at right angLes to the edge.

2. Magnet coil according to Claim 1, characterized in that the wire ends are looped around retaining fingers (21) of the contact lamina (13).

3. Magnet coil according to CLaim 2, characterized in that the contact laminae (13; 25, 26) are metal strips which are bent in a U-shape and grip around the edge of the plug-in plate (5).

4. Magnet coil according to Claim 3, characterized - in that the contact laminae (13), on both sides, have lugs (14) which protrude at right angles, from which tag strips (15) protrude which run parallel to the contact laminae, and that the lugs (14) and tag strips (15) placed congruously on top of one another are inserted into recesses in the end plate (3) and are securely held by means of a catch tooth (12), with the tag strips (14) partly protruding and acting as retaining fingers (21).

5. Magnet coil according to Claim 1, characterized in that the wire ends (28) are looped around retaining pins (29, 30) arranged on the coil body and are welded (31) or soldered point-like to the contact laminae (25, 26).

Amendments to the claims have been filed as follows 1. Electromagnet having a plug-in connection with a coil body of insulation material which comprises a tubular centre section and two end plates, a coil winding and an iron yoke, whereby one of the end plates has a connecting part with a rectilinear edge on which connecting parts are arranged the two wire ends of the coil and their connecting points for the plug-in unit, covered by an insulating coating characterised in that the connecting part is made as a plug-in plate (30) for pushing thereon an edge connector (10), and that the plug-in members are contact laminae (6, 22, 28, 29) which have been evenly arranged on the sides of the plug-in plate (30) and which form congruously arranged, strip-shaped metal contact faces extending at right angles toward the edge.
2. Electromagnet according to claim 1 in sofar that the contact laminae are U-shaped metal strips (28, 29) fastened around the plug-in plate (30).
3. Electromagnet according to claim 2 characterised insofar that the end of the U-shaped metal strips (28,29) are clawed firmly into grooves in the plug-in plate (30).
4. Electromagnet according to claim 2 characterised in that the adjacent sides of the contact lajninae (28, 29) are of different lengths.
5. Electromagnet according to claim 4 characterised by the fact that the two U-shaped contact laminae (28, 29) have been arranged in such a fashion that those legs lying on the same side of the plug-in plate (30) are of different lengths.
6. Electromagnet according to claim 1 characterised in that the wire ends are wound around the retaining hooks (23, 24) of the contact laminae (22).
7. Electromagnet according to claim 1 characterised by the fact that the spool wire ends (19) are looped around retaining fingers (13, 14: and 32 to 35) on the spool body and spot welded or soldered to the contact laminae (6, 28 and 29).