The invention relates to a device for winding a wire on a ring core, which device comprises

- a ring core holder for holding a ring core, which ring core holder comprises a drive for axially rotating the ring core;

- a first carrier rotatable along a first trajectory, which first carrier comprises a first drive for rotating the first carrier along the first trajectory;

- a second carrier rotatable along a second trajectory, which second carrier comprises a second drive for rotating the second carrier along the second trajectory;

wherein the first and the second trajectory do not cross each other, and

wherein a ring core placed in the ring core holder during use has an axial direction which is tangential to the first trajectory of the first carrier and tangential to the second trajectory of the second carrier, and wherein the first trajectory and the second trajectory extend through the opening of the ring core.

Known for the purpose of winding ring cores for for instance transformers are toroidal rapid winding machines, which can arrange copper wire on a ring core. Such winding machines have a carrier which winds wire around the ring core, while the ring core is rotated in a ring core holder. In order to arrange the ring core in the machine the carrier and optionally also the cartridge can be opened. Depending on the construction of the apparatus a segment can be removed from the carrier, or the carrier can be divided into two

substantially identical halves. Such winding machines are for instance described in US 3669365 and DE 393840. Most ring core transformers consist of a plurality of winding layers. In order to increase the quality and durability of the transformers insulating material is arranged between the different winding layers. Arranging of the

insulating layer, i.e. the taping, normally takes place by hand. The manual arranging of the insulation is a bottleneck in the winding process.

The taping is further not without risk either. In many winding machines the carrier is driven by means of a gear ring arranged on the periphery of the carrier. In order to be able to place the ring core a part of the carrier can be removed. In order to gain production speed the part is not always replaced before winding is started. Possible covers for the gear ring are often not placed either. Particularly in the case of smaller ring cores it is necessary to work very close to the rotating gear ring for the manual taping. The risk of injury is therefore not inconsiderable.

Manual taping often does not result in a uniform insulation thickness, since a highly constant overlap between the different runs must be realized for this purpose. It is hereby difficult to predetermine the dimensions of a wound transformer, and the quality of the transformer is not

constant either. It is also easy to arrange too much

insulating material, which is an unnecessary waste of

insulating material.

Space allowing, a second winding machine can

sometimes be set up for arranging the insulating layer

mechanically. This however makes placing of the ring core even more difficult, since two divisible carriers have to be taken into account. The space for manoeuvring is here often very limited because the winding machines, arranged in tandem, have to be placed such that they can wind the same ring core simultaneously . It is now an object of the invention to reduce or even prevent the above stated drawbacks. This object is achieved with a device according to the preamble, which is characterized in that the axial direction of the first carrier and the axial direction of the second carrier are coaxial.

By placing the carrier for the winding wire and the carrier for the insulating tape coaxially it is possible to wind and band simultaneously with a compact machine. It is therefore not necessary for any potentially dangerous, manual operations to be carried out in the vicinity of the ring core during winding. Owing to the coaxial placing, the rapid winding machine can take a much more compact form than in a tandem arrangement.

Because the two carriers can be opened

simultaneously, loading and removal of the ring core is also equally simple as in a rapid winding machine with a single carrier .

Because the two carriers have their own drive means, the winding speeds of the two carriers can be controlled independently of each other. Because the insulating tape is generally much wider than the copper wire, the winding speed of the insulating tape can be much lower than the winding speed of the copper wire. By adjusting the winding speed the overlap between different runs can also be controlled.

The drive means for the carriers can for instance be servomotors, which are controlled by means of a PLC . For the best winding results the control can be chosen such that the tension with which the copper wire or the insulating material is wound is kept constant.

In another embodiment of a device according to the invention the first carrier comprises a supply reel for winding wire. By incorporating a supply reel on the carrier the quantity of copper wire need not be coordinated with the ring core to be wound. It is therefore not necessary to wind on the correct length of copper wire before winding can be started.

In another embodiment of a device according to the invention the second carrier comprises a supply reel for insulating tape.

By incorporating a supply reel with insulating material the quantity of insulating tape which has to be arranged need not be predetermined. The reel can optionally also be replaced during winding, without the ring core having to be removed.

Having a supply reel for copper wire or insulating material also has the advantage that winding material, for instance for different winding runs, can be switched in simple manner .

In another embodiment of a device according to the invention the first carrier is a first divisible ring, which ring extends along the first trajectory.

Constructing the carrier as divisible ring allows the carrier to be bearing-mounted rotatably in a housing of a rapid winding machine in simple manner. Because the carrier is divisible, a ring core can be placed and removed in simple manner. The carrier can for instance have a removable segment in order to create the opening for the ring core. The carrier can also have a pivoting part which provides the necessary opening for inserting or removing a ring core.

In another embodiment according to the invention the first carrier comprises a supply holder, concentric with the first divisible ring, for receiving a winding wire.

Placing a supply holder, such as for instance a supply ring bearing-mounted rotatably on the carrier,

concentrically with the carrier enables a great length of winding wire to be received in simple manner. An advantage of a concentrically placed supply holder is that the space received in the opening of a ring core by the carrier during winding can remain small.

A concentric cartridge for winding wire can also be actively driven in order to keep the tension in the winding wire constant during winding.

In another embodiment of a device, also according to the invention, the second carrier is a second divisible ring, which ring extends along the second trajectory.

The advantages of constructing the second carrier as divisible ring are the same as the advantages stated for the embodiment wherein the first carrier is a divisible ring.

In another embodiment of a device according to the invention the second carrier comprises a supply holder, concentric with the second ring, for receiving an insulating tape .

It can also be advantageous for the insulating tape to use a concentrically placed cartridge which is optionally bearing-mounted rotatably on the carrier. The advantages as described for a concentric cartridge for winding wire also apply to a concentric supply holder for insulating material.

In a preferred embodiment of a device according to the invention the second carrier comprises an elongate guide arm, which guide arm has at a first free end a disengaging edge which forms a substantially right angle with the radius of a ring core placed in the ring core holder during use.

Because the winding material cannot be arranged at right angles to the radius of the ring core by both carriers at the same time in the case of coaxially placed carriers, for winding wire and insulating tape, a guide arm is provided on the second carrier. During winding, this guide arm can guide insulating tape to the ring core at an angle relative to the radius of the ring core differing from that formed by the carrier or supply holder with the radius of the ring core. The somewhat wider insulating tape can hereby be wound uniformly, and the insulating tape can be wound tightly.

The guide arm can guide the insulating tape to a position close to the ring core. The carrier can optionally also be provided with a plurality of guide arms.

In another embodiment of a device according to the invention the guide arm is mounted with a second end pivotally on the second carrier, wherein the guide arm is pivotable between a first and a second position, wherein, when the second carrier rotates, the diameter of the trajectory

circumscribed by the disengaging edge of the guide arm in the first position is greater than the diameter of the trajectory circumscribed by the disengaging edge of the guide arm in the second position.

Mounting the guide arm pivotally enables the

distance from the disengaging edge of the guide arm to the ring core to be varied in simple manner. The pivoting movement of the guide arm can be bounded by arranging end stops.

Another embodiment of a device according to the invention is an embodiment wherein the guide arm comprises spring means, which spring means urge the guide arm into the first position.

By arranging spring means, such as for instance a torsion spring, on the guide arm, the guide arm can control a tensile stress in the insulating tape. The tension in the insulating tape, which can be determined by, among other things, a braking action on the insulating tape or the control of the supply holder of the insulating tape, can provide for the guide arm to be pulled toward the ring core, or even come into contact with it, counter to the spring action. If the tension in the insulating tape decreases, the guide arm can spring back and thus keep the insulating tape tight.

In another embodiment of a device according to the invention the first free end of the guide arm can rotate axially about an axis lying at right angles to the disengaging edge, which axis extends from the first free end to the second end of the guide arm.

Making the part of the guide arm with the disengaging edge rotatable relative to the mounting on the carrier enables the disengaging edge to continue to form a right angle with the radius of the ring core during winding. The disengaging edge can thereby follow the surface of the core during winding. The insulating tape can hereby be

controlled better, also in the case of different sizes of ring core .

In another embodiment of a device according to the invention the disengaging edge is formed by the surface of a pressing roller arranged on the guide arm.

Arranging a pressing roller on the guide arm enables the insulating tape to be guided up to the ring core, wherein the roller rolls over the winding surface of the ring core. There is hereby no shifting due to the ring core also rotating during the winding.

In a further embodiment of a device according to the invention the second divisible ring is bearing-mounted on the first divisible ring.

By arranging the two rings bearing-mounted on each other a very compact construction can be achieved. An

advantage of this is that the minimum opening that a ring core must have in order to be able to be wound on the machine can be smaller. These and other features of the invention are further elucidated with reference to the accompanying

drawings .

Figure 1 is a perspective view of a first embodiment of a device according to the invention.

Figure 2 is an axial view of a second carrier with guide arms .

Figure 3 is a perspective view with exploded parts of a first carrier with concentric supply holder and a second carrier with supply reels.

Figure 4 is an axial view of a ring part of the second carrier, with a guide arm in the first position.

Figure 5 is an axial view of a ring part of the second carrier, with a guide arm in the second position.

Figure 6 is a perspective view of a guide arm.

Figure 7 is a perspective view of a ring part of the second carrier, on which the guide rollers are readily

visible .

Figure 8 is a perspective view of a ring part of the second carrier and a ring core, in which a guide roller lying against the ring core is visible.

Figure 9 is a view axially of the rotation axis of the ring core, in which the rotation of the free end of the guide arm is visible as shown in figure 8.

Figure 1 shows a first embodiment of a device 1 according to the invention, with a ring core holder 2 in which a ring core 3 is placed. Also visible is the second divisible carrier 4 with supply reels 5 for insulating tape arranged thereon. Guide arms 6 for guiding the insulating tape are also shown .

Figure 2 shows an axial view of the second divisible carrier 4 with guide arms 6. The view shows a ring core 3 around which insulating tape 7 is wound. Insulating tape 7 runs from the supply reels 5 for insulating tape 7, via guide rollers 9 and from the surface of pressing rollers 8. Second drive 10 of second divisible carrier 4 is also shown in the view. End stops 11 define the first position of guide arms 6 and end stops 12 define the second position of guide arms 6.

Figure 3 shows a perspective view with exploded parts of a first carrier 13 with concentric supply holder 14 and a second carrier 4 with supply reels 5. It is clearly visible in this figure that the second carrier 4, set apart in the figure, is bearing-mounted on first carrier 13, wherein the second carrier can rotate around guide rollers 15 arranged on first carrier 13.

Figure 4 shows an axial view of a ring part of second carrier 4, with a guide arm 6 in the first position. In the first position of guide arm 6 it lies against end stop 11.

Figure 5 shows an axial view of a ring part of second carrier 4, with a guide arm 6 in the second position.

In the second position of guide arm 6 it lies against end stop 12. Guide arm 6 is thus mounted on second carrier 4 for pivoting about shaft 16.

Figure 6 shows a perspective view of a guide arm 6.

A pressing roller 8 and guide roller 9 are mounted on the first free end 17. First free end 17 can rotate about shaft 18, axially relative to the second end 19 of guide arm 6.

Figure 7 shows a perspective view of a ring part of second carrier 4, in which guide rollers 9 are readily

visible. A holder 20 for a supply reel and a braking device 21 for holding the insulating tape under tension are also shown.

Figure 8 shows a perspective view of a ring part of second carrier 4 and a ring core 3, in which a guide roller 8 lying against ring core 3 is visible. It is also apparent that the first free end 17 of the guide arm is rotated relative to the second end 19 of the guide arm. Figure 9 shows a view axially of the rotation axis of ring core 3, in which the rotation of first free end 17 of the guide arm is visible, as also shown in perspective in figure 8. The disengaging edge formed by the surface of pressing roller 8 clearly lies at right angles to the radius of ring core 3.