The invention relates to a winding unit with a wire magazine for use in a windin.g machine, particular¬ ly for the winding of wire or insulating material on an elongate member or pipe or on a core. The winding unit may be used for the winding of toroidal cores, but could also be used for the winding of other cores.

In existing machines for the winding, of toroidal cores, primarily with wire-shaped material, winding units with magazines are used which are mainly of the following kinds:

1) The coil magazine type,

2) The tubular magazine type,

3) The double ring type,

4) The single ring type, 5) The bandaging type.

In winding units of the coil, magazine type such as known, e.g. from German published specification DE-AS No. 1 228 719, the coil magazine moves in a circular path around the member to be wound and rotates simulataneously around its own axis. The disadvantages of this construction are that the wind¬ ing material must be coiled into, the coil magazine in a preceding operation, and that the supply capacity is limited relative to the dimensions of the circular path on one hand, and of the member to be wound on the other hand. In the winding of toroidal cores, whether they are open or endless, the coil magazine and thereby the supply capacity -will be limited by the hole of toroidal core which is also a disadvantage.

In the tubular magzine type such as known e.g. from US Reissue-Patent No. Re 17 559, a tube is used which is bent into a circular ring in which the wind¬ ing material is forming a spiral. During the winding operation the ring is rotating in its own plane around its own centre and around the member to be wound. The disadvantage of this construction is that the winding material must be twisted and pushed into the tube by means of special apparatus in a preceding operation. A winding ^' unit of the double rinq type such as known e.g. from British patent specification No. 660 218, consists of an advancing ring and a magazine ring. The two rings have nearly the same diameter and a common axis- of revolution. The disadvantage of this construction is that the two rings must first perform an interlocked rotary movement when positioning the winding material on the magazine ring whereafter the interlocking engagement is interrupted, the direction of rotation is reversed, and the winding may take place in a manner analogous to the two above mentioned methods. The fact, that in the double ring type the cross-sectional area is increased relative to that of the tubular magazine type due to the advancing ring, implies that the minimum value of the hole in toroidal cores, whether they are open or endless, will be increased.

In the single ring type such as known e.g. from US Patent No. 3 662 965 an endless ring is used having a U-shaped cross-section, said ring being provided with a lateral slide.

The disadvantage of this type is that the ring must first rotate a-number of revolutions for position¬ ing the winding material on the magazine whereafter the direction of rotation is reversed, and the winding may take place via the lateral slide in a manner analogous to the double ring type. In toroidal cores,

whether they are open or endless, the winding plane will be displaced from the centre of the hole, where¬ by the wire consumption will increase. Furthermore, the minimum value of the hole of the toroidal core will be increased with the thickness of the lateral slide.

The bandaging machine is used to cover a finished winding with a strip-shaped insulating foil. Such a machine may have a magazine comprising two identical rings between which cylindrical rollers are closely arranged. In a machine disclosed in German published specification DE-OS No. 2 427 588 it has been attempted to use this principle for wire winding. When applied for wire winding the principle has two essential disadvantages. On one hand,, the residual hole in the toroidal core will be great, since the wire supply is carried by the extreme part of the rollers having a flange only. On the other hand, due to the fact that the individual cylinders with flanges are rolling during the winding operation, a great friction will arise between the wire supply and the flange, and the wire will break if more than one wire layer is filled into the magazine.

Moreover, it is common to the magazine types described that the wire tension during the winding operation is provided by means of a friction brake This type of brake can only act to increase the nominal• level of wire tension without changing the variation range of the wire tension.

It is the object of the present invention to provide a winding unit working according to a new winding principle and intended particularly, but not exclusively for the winding of toroidal cores, in which the disadvantages of the known winding methods are avoided. In- particular, it is desired to reduce the winding time and to simplify the manipulation

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operations to a level suitable for robot operation. Therefore, there is provided a winding unit with a wire magazine for use in a winding machine for the winding of wire or insulating material on elongate members or cores, particularly endless cores such as toroidal cores, said winding unit being provided with drive means and possibly braking means, and according to the invention this winding unit is characterized in that the cross-section of the supply chamber of the wire magazine has a height and ^' a width substantially greater than the wire diameter, that the wire supply is stationary relative to the wire magazine during the winding operation, and that the wire magazine is constructed for being emptied from the bottom.

Thereby it is obtained that winding of a core may start simultaneously with filling up the magazine, since the winding material, which is preferable lacquered copper wire, is carried directly down into the magazine and out through the bottom thereof in an arbitrary point and down to engage the member to be wound. During rotation of the magazine winding of the member and filling of the magazine are taking place simultaneously. When the magazine is filled sufficiently, the wire is cut, and the wire supply in the magazine is wound on to the member without any need to change the direction of revolution or even stop the magazine.

If the wire magazine is emptied from the bottom opposite a stationary, arbitrary point below the bottom of the wire magazine on a wire advancing . member, which is separated from the wire magazine and arranged around a common axis of revolution there¬ with so that the wire magazine and the wire advancing member are freely rotatable relative to each other, but with the same preselected direction of revolution, a stationary well-defined point is obtained via which

the wire may be taken out from the bottom of the magazine. The magazine will be suitable even for great wire diameters.

By constructing the wire magazine to be emptied from the bottom through a flexible slot, the smallest possible ^' residual hole in would toroidal cores will be obtained, since the winding unit when filled ^' will not occupy substantially more space than the quantity of wire wound. Thereby a residual hole may be obtained, which is essentially smaller than what can be achieved in known winding machines.

If the wire magazine and the wire advancing member each consists of two substantially annular , members which are positioned concentrically around the common axis of revolution, a winding unit having small dimentions is obtained so that the residual hole in a toroidal core may be small.

A small residual hole in a toroidal core may also be obtained in- another embodiment which is characterized in that the wire magazine has a greater diameter than the wire advancing member and surrounds the latter, that the wire magazine has a substantially 0- or U-shaped cross-section in which the wire is collected, that the wire magazine has a flexible central slot through which the wire may be pulled out and that the wire magazine and the wire advancing member are supported by individual sets of bearing means . According to. a further embodiment, which is characterized in that the wire magazine has a greater diameter than the wire advancing member and surrounds the latter, that the wire magazine has a substantially 0- or U-shaped cross-section in which the wire is collect¬ ed, and part of the bottom of the wire magazine is constituted by bearing means mounted on the wire advancing member, said bearing means reducing the

the friction between the concentric annular members and simultaneously forming the stationary arbitrary point via which the magazine is emptied, a reduction of the friction is obtained allowing operation at greater winding speeds.

If both the wire magazine and the wire advancing member form an open ring, toroidal or other endless cores may be wound without any need to open the winding unit. A winding machine, which is very reliable in operation and easily adjustable-, may be obtained by use of a winding unit in which the bearing means between the magazine and the wire advancing member comprises one ox more ball races or the bearing means comprises slide or ball bearings secured to the wire advancing member.

In a still further embodiment the wire magazine is braked by a separate braking-device act¬ ing solely on the wire magazine whereby a constant wire tension during the winding operation may be ob¬ tained.

In particular advantageous embodiments of the flexible slot this slot may be formed either in the bottom of the wire magazine by an elastic material or it may be formed by two annular parts, at least one of which is elastically secured to be concentric with its wire magazine ring.

A mechanically very simple construction of the flexible slot may be obtained if the two symmetric rings of the wire magazine are suspended in elastic bearings to be pressed against each other by elastic forces.

A possibility of very high winding speeds with thin wires may be obtained in a winding unit having a flexible slot if the latter is formed by an excess air pressure constituting an air cushion supporting a portion of the wire supply, which excess air pressure

may be formed by jet-like means on the wire magazine during rotation thereof.

In the following the invention will be explained in further detail with reference to the accompanying drawings in which

Fig. 1 shows a winding unit _. according to the invention having a flexible slot,

Fig. 2 is a sectional view of the winding unit shown in Fig. 1,

Fig. 3 shows a winding unit according to the invention having open wire magazine and wire advancing member,

Fig. 4 is a sectional view of bearing means in the winding unit shown in Fig. 3, Fig. 5 shows an embodiment having open rings,

Fig. 6 shows an embodiment having two sets of bearing means,

Fig. 7 shows in detail the embodiment shown in Fig. 6 with a flexible slot, and Fig. 8 shows an embodiment of the magazine construction shown in Figs. 6 and 7.

In Fig. 1 a winding unit is shown which comprises a wire magazine 42 supported by guide rollers 60 and caused to rotate by drive means 61 via a belt 51. The wire material 45 is carried from a wire supply 46 outside the winding unit through guide means 47 along with the belt 51 to the wire magazine 42 from which it is guided further on through the bottom of the wire magazine having a flexible slot as shown at 62 in Fig. 2 for engagement with the core 49 to be wound. The free end of the wire material 45 is held against the core 49, and ^" when the wire magazine 42 is caused to rotate, the wire 45 will be carried around the core 49. In order to position the windings correctly on the core 49 the latter and the winding unit must be displaced relative to each other during

the winding operation. This may take place in a conventional manner by means of supporting members 50 for the core 49.

As shown in Fig. 2 the wire magazine comprises two symmetrical rings 42 which are secured relative to each other by means of guide rollers 40. The flexible slot 62 is formed between two rubber lips 63.

As shown in Fig. 1 the wire magazine 42 is divided into wD sectors having junctions 57 so that the endless ring of the magazine may be opened for the arrangement of endless toroidal cores.

In Fig. 3 a winding unit is shown comprising a wire advancing member 11 and a wire magazine 12, which may rotate freely relative to each other with the aid of bearing means 13. The rotation of the advancing member 11 is caused by special driving means 14 in the form of gears or friction wheels engaging the advancing member 11. The wire material 15 is carried from a supply 16 outside the winding unit through guide members 17 to the wire magazine 12 from which it is guided further on through the bottom of the wire magazine via a stationary point 18 on the advancing member 11 to the core 19 to be wound. The free end of the wire material is held against the core 19, and when the advancing member

11 and thereby the stationary point 18 is caused to rotate, the wire 15 will be carried around the core 19 and, simultaneously, wire is filled into the wire magazine 12. In order to position the windings correctly on the core 19 the latter and the winding unit must be displaced relative to each other during the winding operation. This may take place in a conventional manner with the aid of supporting means 20 for the core 19. In Fig. 3 a braking device

21 in the form of a belt encircling the wire magazine

12 on part of its circumference and engaging the wire

magazine is shown. As an example,fouridentical bearing means 13 are shown in Fig. 3 between the advancing member 11 and the wire magazine 12, and in Fig. 4 a single bearing means 13 is shown in detail. In this .embodiment the advancing member is divided into two symmetrical arranged rings 22. The bearing means comprises two ball bearings 23 individually arranged in each of rings 22 and connected by a common shaft 24. keeping the two rings together. The wire magazine comprises two symmetric rings 25 arranged between the two rings 22 of the advancing member and position¬ ed relative thereto by means of a roller 26 on the shaft 24. The two rings 25 of the wire magazine may roll on the roller 26 whereby the wire magazine 12 may be caused to rotate -relative to the advancing member

11 around the common axis of rotation. One of rollers 26 may constitute ;he stationary point 18 on the advancing member 11 ' via which the wire material 15 is drawn out from the bottom of the wire magazine 12. As shown in Figs. 3 and 4, the wire magazine

12 and the wire advancing member 11 are divided into sectors with junctions 27 so that the endless ring of the advancing member 11 and the magazine 12 may be opened for'the arrangement of endless toroidal cores. The wire 15 may be taken out from the bottom of the supply via the roller 26 constituting the above mentioned stationary point 18.

In Fig. 5 an embodiment is shown in which the wire advancing member 11 and the wire magazine 12 are open rings which may be directly arranged around endless cores.

In Fig. 6 an embodiment is shown in which the wire magazine 12 encloses the wire advancing member

11. In this case the wire magazine is supported by separate bearing means 30, which are carried by consols on the winding machine, and the advancing

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member 11 is constituted by an interrupted ring in one piece which are positioned freely relative to the magazine.

Fig. 7 shows in detail the bearing means 30 and 31, the wire magazine 12 having rubber lips 32 and the advancing member 11 of the embodiment shown in Fig. 6.

In Fig. 8 an alternative embodiment of the magazine shown in Figs. 6 and 7 is shown. The figure shows a practical embodiment of a magazine construction having a circular cross-section so that the.residual hole in a would toroidal core will have the same size as the cross-section of the magazine and the advancing ring together.

A winding operation performed by a winding unit according to the invention can be described to comprise the following steps: a) The wire is carried from the supply roll through the bottom of the magazine to engage the core and is held against the core. b) Rotation of the magazine is initiated. Each time a winding has been positioned on the core a corresponding length of wire has been drawn from the wire magazine through the bottom thereof whereby the point of drawing has been subjected to a displacement corresponding to one winding length or a corresponding displacement has occurred between the wire magazine and the guide ring. Simultaneously, the magazine has moved a length corresponding to its own circumference plus the length of a winding, and a corresponding wire length has been supplied to the magazine. c) The wire is cut when a sufficient supply for the actual operation has been filled into the magazine, and the winding operation continues with the same direc¬ tion of rotation until the magazine is emptied. The winding unit 'with a wire magazine according to the invention may be used for the winding of wire or

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insulating material on an elongate member of any kind whether curved or rectilinear. In particular it is suitable for the winding of cores for electrical coil and transformers such as endless toroidal cores.