GB2300688A

GB2300688A - Core carrier

Info

Publication number: GB2300688A
Application number: GB9608166A
Authority: GB
Inventors: Reiner Schulze; Gerd Hebbel
Original assignee: Beiersdorf AG
Current assignee: Beiersdorf AG
Priority date: 1995-05-11
Filing date: 1996-04-19
Publication date: 1996-11-13
Anticipated expiration: 2016-04-19
Also published as: GB2300688B; GB9608166D0

Abstract

In a core carrier 1 for carrying winding cores 3 for material 4, in particular self-adhesive tapes, the core carrier 1 comprises a flexible outer ring 7, which has a slit on one side, an inner ring 5 and at least one elastic ring 6 therebetween. Cutouts 51 are provided in the outer ring 7, the elastic ring 6 and/or the inner ring 5, which serve to ensure the frictional connection between inner ring 5 and outer ring 7 when a radially acting force is exerted externally on the outer ring 7, as occurs when drawing cores 3 onto the core carrier 1.

Description

CORE CARRIER The invention relates to a core carrier for clamping cores onto which material to be wound, in particular self-adhesive tapes, is wound.

The winding of material to be wound onto cores which are arranged on core carriers individually or plurally on winder sbafts, and are driven by using the core carriers, is prior art. A core carrier of this type must fulfil a multiplicity of requirements placed upon it: - When pushing a core made, for example, of cardboard over the core carrier, no damage to the core must occur.

- Secure fixing of the core must be ensured, so that slipping of the core carrier through the core does not occur.

- The core carrier should have only a low weight.

- It must be distinguished by a long lifetime, coupled with excellent maintainability.

The invention is, then, based on the object of providing a core carrier which does not have the disadvantages of the prior art, or at least not to the same extent, and which simultaneously fulfils the requirements set.

According to the present invention, there is provided a core carrier for clamping cores in order to wind material to be wound, in particular self-adhesive tapes, the core carrier having a basic element which serves to receive the core and to transmit the torque of the winder shaft to the core, characterized in:that the basic element has a flexible outer ring, which is designed as a ring slit on one side, and in that the basic element has a carrying ring, a multiplicity of cutouts being provided in the outer ring and/or the carrying ring, into which cutouts at least one elastic clamping ring of the basic element, which serve to ensure the frictional connection between carrying ring and outer ring, makes way when a radially acting force is exerted externally on the outer ring, such as occurs in particular when drawing cores onto the core carrier.

If a material to be wound is intended to be wound onto cores, before putting the winder shaft into operation the individual core carriers on the winder shaft must be fitted with empty cores which, for example in the case of winding an adhesive tape, may consist of cardboard.

For this purpose, the envisaged number of core carriers is firstly pushed onto the winder shaft. The core carriers are axially clamped firmly against one another. Next, the core carriers are fitted with a corresponding number of cores, the cores in the centre of the winder shaft in particular having to be guided over a relatively large number of core carriers. Since the internal diameter of the cores is somewhat smaller than the external diameter of the core carriers, this is only possible without damaging the cores if the core carriers are flexible, that is to say can reduce their external diameter somewhat when the cores are being drawn onto the core carriers.

This required flexibility is ensured by the basic element, which is significant in terms of the invention, of the core carrier according to the invention.

The basic element is composed of the outer ring and carrying ring parts, as well as a possible plurality of clamping rings. The flexible outer ring is a ring which is slit on one side, so that it is capable of changing its diameter. Furthermore, the edges of the outer ring are advantageously slightly bevelled in order to reduce further the risk of damaging the cores during the drawingon process. The inflexible carrying ring advantageously has at least one circumferential groove in which at least one elastic clamping ring can be received. The flexible outer ring is preferably clamped over the carrying ring in such a way that the contact between the outer ring and the carrying ring takes place only via the elastic clamping ring or rings. In this case, the tension is sufficiently large for the clamping ring or rings to ensure a frictional connection between carrying ring and outer ring.

If an external radial pressure is exerted on the basic element, such as occurs during drawing of a core onto the core carrier, the outer ring is compressed. The pressure acts via the outer ring on the elastic clamping ring or rings. If the outer clamping ring or rings is given the capability of making way, because of the pressure, in correspondingly provided cutouts, preferably in the carrying ring and/outer ring, the diameter of the clamping ring or rings is reduced, since the latter change, as a result of the force acting on them, from a previously preferably circular form into a flatter elliptical form, and hence the diameter of the outer ring is also reduced at the same time. This reduction in size of the external diameter of the core carrier permits the core to be pushed onto the core carrier without great resistance.

The cutouts which have already been mentioned can be made in many ways. They are preferably located in the carrying ring, specifically as continuous bored holes and/or discontinuous blind holes at regular intervals in the axial direction. However, in addition to this, continuous bored holes and/or discontinuous blind holes at regular intervals in the radial direction also prove to be advantageous. Moreover, the cutouts may also be provided in the outer ring, once more as discontinuous blind holes and/or continuous bored holes at regular intervals in the radial direction. The different forms of the cutouts can also be made in any desired combination.

As an alternative to the cutouts in the carrying ring and/or outer ring, a similar effect can be achieved by special shaping of the clamping rings. The clamping rings themselves in this case contain the necessary cutouts as a result of their special configuration, in order to enable them to make way.

The core carrier according to the invention has a further series of advantages. Because of the special constructional design of the basic element, in spite of its flexibility the friction between the core and the outer ring is, however, so great that undesired slipping through of the core during the winding process is excluded. These high holding forces between core and core carrier at the same time prevent a lateral inherent movement of the core on the core carrier. Hence, disadvantageous displacement of the core during the winding process is eliminated.

Because of the small number of individual parts which the core carrier comprises, particularly costeffective production is possible, particularly since in addition the elastic clamping rings can be standard parts.

Furthermore, the comparatively simple construction ensures very good maintainability.

In the case of the particularly advantageous production of the entire core carrier from Plastic for

example from Novatron HPVXfrom the PolyPenco company, a low weight of the core carriers and hence of the entire winder shaft fitted with a plurality of core carriers is still achieved. Furthermore, the core carriers made of the material mentioned are characterized by high stability.

In the case of the core carriers which are located on the winder shaft, the outer rings are subjected to wear which is very low but present, as a result of the continual drawing on of the empty cores and drawing off of the finished cores wound with adhesive tape. Furthermore, externally acting, unintentional damage to the outer rings cannot be excluded. These two factors have the effect that the outer rings of one or more of all the core carriers drawn onto the winder shaft must be exchanged at irregular intervals. The design according to the invention of the outer ring as an open ring allows it to be changed very conveniently, in that the outer ring is pulled in the radial direction until it snaps over the carrying ring, which is surrounded by the outer ring. As a result of the advantageous construction of the outer ring, it is no longer necessary for this process to disassemble the winder shaft, to draw all the core carriers off the winder shaft, to exchange the defective core carrier or carriers and then to reassemble everything, which results in a very long interruption to the winding process.

The drawing on of the new ring is then carried out likewise very quickly in a corresponding manner, with the result that the winding process is interrupted altogether only for a very short time for the exchange of damaged outer rings.

Furthermore, the advantageous construction of the outer ring allows the particularly simple exchange of this wearing part when the core carriers are disassembled, by means of snapping them over laterally.

The drive of the core carriers on the winder shaft can be carried out in a known way. For example, an intermediate dog ring can in each case be provided between the individual core carriers. The dogs of the intermediate dog rings in this arrangement project into a groove provided in the winder shaft, so that the rings are forcible carried along during the rotation of the shaft.

Because of the axial pretension of core carriers and intermediate dog rings, a frictional force between ring and core carrier, the so-called frictional force, results from the rotation of the rings. This frictional force finally ensures that the core carriers are likewise set rotating as a function of the intensity of the pretension and of the rate of rotation of the winder shaft.

The invention will be further described by way of non-limitative example, with reference to the accompanying drawings, in which: Figure 1 shows in section a core carrier in accordance with an embodiment of the invention; Figure 2 shows in longitudinal section a core carrier in accordance with the invention; and Figure 3 shows in section an alternative embodiment of the invention.

Shown in Figure 1 is a core carrier (1), with which the winder shaft (2) is fitted, in lateral section.

Drawn onto the core carrier (1) is a core (3), on which there is already wound material (4). The basic element of the core carrier (1) comprises the three components of the carrier ring (5), the clamping ring (6) and the outer ring (7). The carrying ring (5) of the core carrier (1) is connected to the winder shaft (1) by a frictional force, as shown, by means of an intermediate dog ring (8) or by means of another suitable measure. When the winder shaft (2) is rotated, the carrying ring (5) and hence, finally, the core (3), are likewise brought into rotation. To transmit the torque to the outer ring (7), which is configured as an open ring, use is made of the elastic clamping ring (6), which presses the outer ring (7) outwards.As a result, the outer ring exerts a radially acting force on the core (3) which is seated on it, which leads to the core (3), on which the material (4) to be wound is wound, being clamped in such a way that a frictional connection is produced between the outer ring (7) and the core (3).

In the carrying ring (5), axial cutouts (51) are provided in order to give the elastic ring (6) the capability of moving away into the free spaces under external loading, when, for example, a core (3) is drawn onto the core carrier (1). In order to reduce the risk of damage to the core (3) further, the outer ring (7) is slightly bevelled at its outer edges.

Figure 2 shows, in section, a winder shaft (2) on which a plurality of core carriers (1) are arranged alongside one another. A groove (52), which serves to receive the elastic ring (6), is particularly advantageously provided in the carrying ring (5) of the core carriers.

Shown in Figure 3 is a basic element of a core carrier (1), whose clamping ring (6) has the cutouts (61) as a result of its specific shaping. By contrast, no further cutouts are provided in the carrying ring (5).

Claims

1. A core carrier for clamping onto a winding shaft cores for winding material to be wound, the core carrier comprising a basic element which serves to receive the core and to transmit the torque of the winder shaft to the core, the basic element comprising: a flexible outer ring, having a slit on one side, a carrying ring, and at least one elastic ring for ensuring a frictional connection between the carrying ring and outer ring, a multiplicity of cutouts being provided in at least one of the outer ring, the carrying ring or the elastic clamping ring for providing resilient deformation when a radially acting force is exerted externally on the outer ring, such as occurs in particular when drawing cores onto the core carrier.

2. A core carrier according to claim 1, wherein at least one circumferential groove, which serves to receive the at least one clamping ring, is machined into the carrying ring of the basic element.

3. A core carrier according to claim 1 or 2, wherein the outer ring is slightly bevelled at its outer edges.

4. A core carrier according to claim 1, 2 or 3, wherein the cutouts are arranged in the carrying ring of the basic element at regular intervals in the axial direction as continuous bored holes and/or as discontinuous blind holes.

5. A core carrier according to claim 1, 2, 3 or 4, wherein the cutouts are arranged in the carrying ring of the basic element as discontinuous blind holes and/or continuous bored holes at regular intervals in the radial direction.

6. A core carrier according to any one of the preceding claims, wherein the cutouts are arranged in the outer ring of the basic element as discontinuous blind holes and/or continuous bored holes at regular intervals in the radial direction.

7. A core carrier according to any one of the preceding claims, wherein the elastic clamping ring is receivable into said cutouts, which are provided in the outer ring and/or the carrying ring, under said radially acting force.

8. A core carrier according to any one of the preceding claims, wherein the cutouts are provided in the clamping rings.

9. A core carrier according to any one of the preceding claims, wherein all the components of the core carrier are produced from plastic.

10. A core carrier constructed and arranged to operate substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.