EP0520348B1 - Gripping device for winding core - Google Patents

Description

The invention relates to a winding shaft with a multiplicity of self-tensioning individual winding bodies for winding cores which are rotatably and drivably mounted on it, a resilient tensioning device being inserted into an annular groove of each individual winding body, the outer diameter of which is larger than the inner diameter of the winding cores, the resilience of the tensioning device being a sliding one Postponing the winding cores in the axial direction allows by the tensioning device contains flexible spring elements in the radial direction and consists of segments whose end faces are chamfered and are arranged radially displaceably on intermediate pieces provided with a similar chamfer angle and connected to the bottom of the annular groove.

In winding machines, in particular in combined slitting and winding machines, for example for magnetic tapes, the winding shafts each accommodate a large number of winding cores. Fitting the shafts with winding cores is problematic because the numerous wound cores should be pulled off the winding shaft very quickly and replaced with empty winding cores in the correct position. The tensioning device should not hinder easy and trouble-free displacement of the winding cores on the shaft when loading. Therefore, there are already numerous tensioning devices on the winding shaft, such as tilting chips, tensioning rollers, tensioning pins or the like. These tensioners represent mechanically complex constructions that drive up the costs of the winding shaft. The difficulties become all the greater if single winding bodies with separate friction are used.

From EP-A-0 250 898 a clamping device is known, which consists of a rotatably mounted block seated on a circular disc, which contains two opposing bushings as clamping elements, each of which is spring-supported Have balls and the tensioning elements are located at a distance from the circular disk, so that when pushed onto the block the winding core rests on one side against the circular disk and is arranged in the correct position on the other side by the tensioning elements. With this arrangement, it is extremely disadvantageous that the loading and unloading of the winding cores on the shaft is extremely time-consuming.

DE-A-22 41 783 describes a tensioning device in which tensioning prisms are arranged on both sides of a winding core along a regular polygon lying parallel to the base surface of the winding core and which are each rotatable about the prism edge.

• DE-GM 88 15 051. Beschrieben ist ein Wickelkernhalter bestehend aus einer ringförmigen Blattfeder sowie einem darunterliegenden Gummikissen, welches eine ungewollte Drehung der Blattfeder verhindern und die Elastizität der Blattfeder verstärken soll.
• EP-A-0 133 648 und EP-A-0 356 744. Hierbei ist die Spannvorrichtung als ein in radialer Richtung nachgiebiger Wellenring oder Nabenkranz oder als Spannring abwechselnd gegen einander gerichteten Zungen ausgestaltet, der auf einer nachgiebigen Unterlage wie zum Beispiel einem O-Ring oder einem Gummiband aufliegend.
• Die EP-A-0 297 609 beschreibt als Spannelement kreiszylindrische Segmente, die durch eine in einer zentralen Nut liegende Spiralfeder zusammengehalten werden und wobei zwischen Innenring und den Segmenten auf beiden Seiten Silikonschläuche als federnde Elemente angeordnet sind.

Clamping devices of the generic type mentioned above are described in the applications

• DE-GM 88 15 051. A winding core holder is described consisting of an annular leaf spring and an underlying rubber cushion, which is intended to prevent unwanted rotation of the leaf spring and to increase the elasticity of the leaf spring.
• EP-A-0 133 648 and EP-A-0 356 744. Here, the tensioning device is designed as a shaft ring or hub ring, which is flexible in the radial direction, or as a tension ring alternately directed against one another, which is placed on a flexible base, such as an O- Ring or a rubber band.
• EP-A-0 297 609 describes, as a tensioning element, circular-cylindrical segments which are held together by a spiral spring lying in a central groove and wherein silicone tubes are arranged as resilient elements between the inner ring and the segments on both sides.

In the aforementioned applications, it is disadvantageous that the spring action is not time-stable and there is also insufficient spring travel, so that, at least after a long period of use, the location-stable fixation of the winding cores on the tensioning device is no longer guaranteed, and therefore the winding behavior becomes unsatisfactory.

DE-A-10 50 964 relates to a winding sleeve for pushing on a winding tube, consisting of a one-piece solid core, into which dovetail-shaped slots are milled distributed over the circumference and extending in the axial direction. These contain axially insertable, correspondingly shaped, radially displaceable segments, which are biased by axially extending leaf springs arranged between the core and the segment, and the force transmission between segments and winding tube is supported by centrifugal force.

• der Einzelwickelkörper eine glatte Oberfläche hat, um den Abrieb beim Auf- und Abschieben der Wickelkerne zu verringern
• der Federweg groß sein soll
• die Spannkraft des Federelements durch dessen Abmessung einfach veränderbar ist
• wenig Bauraum erforderlich ist, um einen großen Durchmesser der Wickelwelle zu ermöglichen.

The present invention had for its object to provide a tensioning device of the generic type mentioned above, wherein

• The single winding body has a smooth surface in order to reduce the abrasion when the winding cores are pushed on and off
• the travel should be large
• the clamping force of the spring element can be changed easily by its dimension
• little space is required to allow a large diameter of the winding shaft.

According to the invention the object was achieved with a winding shaft with the features mentioned in the characterizing part of claim 1. Details of the invention emerge from the subclaims, the description and the drawings.

Figur 1

einen Querschnitt durch eine erfindungsgemäße Spannvorrichtung

Figur 2

einen Längsschnitt durch einen Teil der Spannvorrichtung gemäß Figur 1

Figuren 3 und 4

entsprechende Längs- beziehungsweise Querschnitte einer anderen erfindungsgemäßen Ausführungsform

Figur 5

einen Querschnitt durch eine weitere Ausführungsform

Figuren 6 und 7

Längsschnitte durch weitere Ausführungsformen der Zentriervorrichtung für die Wickelkerne.

The invention will now be explained in more detail with reference to the drawings and shows

Figure 1

a cross section through a tensioning device according to the invention

Figure 2

2 shows a longitudinal section through part of the tensioning device according to FIG. 1

Figures 3 and 4

corresponding longitudinal or cross sections of another embodiment according to the invention

Figure 5

a cross section through a further embodiment

Figures 6 and 7

Longitudinal sections through further embodiments of the centering device for the winding cores.

Figures 1 and 2 show a preferred embodiment of the present invention. On a winding shaft (8) sit next to each other individual winding body (6) (only one copy is shown) with a circumferential annular groove (14), in which the clamping device to be described in detail sits. The torque transmission between the winding shaft and individual winding bodies can take place via an eddy current clutch, friction clutch, which is loaded, for example, with compressed air or a somehow braced bearing, is not the subject of this invention.

A plurality of cylindrical segments (2) are arranged in the annular groove, the two end faces (13) of which are chamfered. The segments described are anchored by intermediate pieces (3) which are mushroom-shaped in cross section and which are attached between two segments to the bottom of the annular groove and are correspondingly bevelled in the opposite way to the end faces (13) of the segments. Between the bottom of the annular groove (14) and the inner surface of the segments (2), a leaf spring (4) is inserted as a spring element, which is supported with its two free ends at the end of the segment and with its central part on the bottom of the annular groove. The dimensions of the leaf spring determine the clamping force of the clamping element. The outer surface of the segments (2) protrudes slightly beyond the peripheral surface (5) of the single winding body (6). The intermediate parts (3) limit the radial spring travel of the segments (2) to the outside. In addition, the intermediate parts (3) prevent rotation of the segments (2) in the circumferential direction by the torque transmission from the individual winding body (6) to the winding core (9).

In order to allow the axially slidable winding core (9) to be properly centered on the tensioning device (2, 4) on the individual winding body, each segment has an annular bead (10) on both sides of its outer surface, the distances between the two annular beads being the width of the winding core correspond.

Another preferred version is shown in FIGS. 3 and 4, respectively. In this case, four spring elements (18) are provided per segment, consisting of coil springs (15) which are inserted in sleeves (16) which are in the bottom of the annular groove (14) and bear ball thrust pieces (17) at their free end, which counteract press the inside of the segments (2). Two spring elements described in this way are arranged on both sides of both ends of the segment.

The arrangements described above still leave numerous variants open, some of which are shown in FIGS. 5 to 7. As can be seen from Figure 5, the leaf spring (4 ') can be provided with an opening in its central part and is fastened to the intermediate piece (3) on the bottom of the annular groove, while its two free ends on the inside of two adjacent segments ( 2), the next leaf spring (4 '') and so on.

Likewise, as can be seen from FIG. 6, the bead (10) can only be arranged on an outside of the segment (2), while a spring-loaded ball thrust piece (10 ') is arranged on the opposite side and in this way represents a snap-in or centering device for the winding core (9). Another variant can be seen from FIG. 7. The winding core is brought to a stop on a bead (10); the ball thrust piece (10 '') is attached this time to the intermediate piece (3) lying between the segments (2).

• Eine sichere Fixierung des Wickelkerns sowie eine genaue Positionierung rechtwinkelig zur Drehachse, so daß kein Taumeln der Wickelkerne oder ein seitliches Wandern eintreten kann.
• Beim Überschieben der Wickelkerne entsteht kein Abrieb wegen der glatten Oberfläche der Segmente.
• Es besteht ein großer Federspannweg, was besonders wichtig ist, da sich der Innendurchmesser des Wickelkerns beim Bewickeln mit Magnetband verkleinert.
• Der Wickelwellendurchmesser kann infolge der geringen Bauhöhe sehr groß gewählt werden, wie auch aus den Abbildungen hervorgeht, so daß nur geringe Durchbiegung der Wickelwelle eintritt, auch wenn die zahlreichen auf ihr aufgeschobenen Wickelkerne mit einer größeren Bandlänge beispielsweise mit Magnetband Gewickelt sind.

The clamping devices described achieve the objects on which the invention is based and offer the advantages mentioned below.

• A secure fixation of the winding core and an exact positioning at right angles to the axis of rotation, so that no wobbling of the winding cores or lateral wandering can occur.
• When the winding cores are pushed over, there is no abrasion due to the smooth surface of the segments.
• There is a large spring tension path, which is particularly important since the inner diameter of the winding core is reduced when it is wound with magnetic tape.
• The winding shaft diameter can be chosen very large due to the low overall height, as can also be seen from the figures, so that there is only a slight deflection of the winding shaft, even if the numerous winding cores pushed onto it are wound with a larger tape length, for example with magnetic tape.

Suitable as winding cores are the so-called NAB cores or winding cores according to DE 24 48 853, which have axial deformations on both sides, which protect stacked cores against shifting or twisting.

example

On a separating machine, a 65 cm wide plastic carrier web with a magnetic coating is cut into approximately 50 strips each 1.27 cm (1/2 ") wide and the strips alternately on two complete tensioning devices at a speed of up to 500 m / min., so that on each winding shaft 25 reels up to a length of 5,000 meters were wound on each winding core, which gives a total weight of the reels of 50 kg on each winding shaft Winding pattern.

Claims (4)

1. A winding shaft (8) having a multiplicity of self-tensioning individual winding elements (6) for winding mandrels mounted on it in such a way that they can rotate and be driven, a compliant tensioning means being inserted in each case in an annular groove (14) of each individual winding element (16), the outside diameter of which means is greater than the inside diameter of the winding mandrels, the compliance of the tensioning means allowing the winding mandrels to be pushed on by sliding in the axial direction by virtue of the fact that the tensioning means includes spring elements (4, 4', 4'', 18) which are compliant in the radial direction, and comprises segments (2), the end faces of which are beveled and are arranged radially displaceably on intermediate pieces (3), which are provided with a similar bevel angle and are firmly connected to the bottom of the annular groove, wherein the segments (2) are distributed along the circumference (5) of each individual winding element (6) and are cylindrical-annular, the mutually facing end faces of which segments are arranged on the inner face (7) of an intermediate piece (3) arranged in each case between two segments, and the intermediate pieces have a mushroom shape, wherein one or more spring elements (4, 4', 4'', 18) arranged so as to be distributed in the circumferential direction are seated between the bottom of the annular groove (14) and the inner face of the segments, and wherein the segments (2) have an annular bead (10) on at least one outer side of their circumferential surface and/or wherein a resiliently flexible ball thrust piece (10', 10'') is mounted on an opposite outer side of the segments or of the intermediate piece (3), the axial spacing of the annular beads or between the annular bead and ball thrust piece corresponding to the width of the winding mandrels.
2. The winding shaft as claimed in claim 1, wherein the spring element is a leaf spring (4), the length of which corresponds approximately to the length of the segment (2) and the two ends of which are supported against the inner side of the segment, whereas the central part of the spring is supported against the bottom of the annular groove (14).
3. The winding shaft as claimed in claim 1, wherein the spring element is a leaf spring (4'), which is connected to the intermediate part (3) via its central part, which is provided with an opening, and the two ends of said leaf spring bear against the inner side of two neighboring segments.
4. The winding shaft as claimed in claim 1, wherein the spring element (18) is a helical spring (15), the one end of which is supported in a bore provided on the bottom of the annular groove (14) and the other end presses on a ball thrust piece (17), which protrudes out of a sleeve (16) and presses against the inner side of the segment (2), four such spring elements per segment in each case being distributed in pairs at both ends.

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