DE20312076U1 - Cable drum system for crane has a plastic film inserted between the cable windings to reduce chaffing damage - Google Patents

Abstract

A cable drum (3) system for a crane has a separate reel (6) for dispensing a plastic film (4) which is wound onto the drum with the cable, and which separates the cable windings. This reduces chaffing and pressure welding between the cable windings and extends the operating life of the cable. The plastic strip is rewound onto its reel when the cable is paid out, and is reused when the cable is drawn in. The dispensing reel is synchronised with the drum drive.

Description

N/Sympt-001-DE-G

04.08.2003

GS

Applicant : sympat GmbH, Further Straße 212, 90429 Nuremberg

Designation : Lifting and/or conveying device

Description

The invention relates to a lifting and/or conveying device, in particular a crane, which has at least one rope, in particular a wire rope, which can be wound onto or unwound from a dispenser roll. Furthermore, the invention relates to a lifting and/or conveying device, in particular a crane.

In lifting and/or conveying devices, especially cranes, a traction rope is usually provided with which the load to be lifted or conveyed can be moved. In order to position the load accordingly, more or less rope is wound onto a dispenser drum that is driven by an electric motor.

Detailed investigations into the service life of the ropes used in the lifting and/or conveying devices mentioned above have revealed that the service life of wound steel ropes is considerably shorter than that of non-wound ropes. It is assumed that during the winding process the rope digs into the rope windings already on the dispenser roll in such a way that micro-welding of the rope material occurs. The individual rope windings on the dispenser roll then have a metallic, material-locking connection, albeit a small one. When the rope is unwound from the dispenser roll again, these micro-weldings are torn apart again, damaging the steel material from which the rope is made. This results in high material stress, which significantly reduces the service life of the rope.

The invention is therefore based on the object of proposing a lifting and/or conveying device with which it is possible to extend the service life considerably. In particular, the rope should be wound onto

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The dispenser roll and the rewinding process must be handled in such a way that the rope material is not damaged.

The solution to this problem is achieved by the invention with the features of claim 1. According to the invention, it is provided that when the rope is wound onto the dispenser roll, a separating medium is introduced between the individual rope windings of the rope on the dispenser roll in such a way that contact between the rope windings is at least partially, preferably completely, prevented.

The separating medium prevents direct contact between the individual rope windings - at least to a large extent; there is no high surface pressure between metal and metal, so that spot welding of the individual metal rope windings is excluded. This significantly increases the service life of the rope.

Preferably, the separation medium is designed as a strip-shaped flat or curved web; in particular, a plastic web is considered.

When feeding the separating medium between the individual turns of the rope, it can be unwound from a separating medium roll assigned to the dispenser roll. It can also be provided that the rotary movement of the dispenser roll is synchronized with the rotary movement of the separating media roll. This synchronization of the rotary movements is preferably carried out using mechanical means.

Finally, it can also be provided that when the rope is rewound from the dispenser roll, the release medium is rewound onto the release medium roll.

The lifting and/or conveying device according to the invention, in particular the crane, has at least one rope, in particular a wire rope, and a dispenser roll on which the rope can be wound up or unwound. The design according to the invention provides that a separating medium roll is assigned to the dispenser roll, from which a separating medium is unwound between the individual rope windings of the rope on the dispenser roll when the rope is wound up on the dispenser roll, so that contact between the rope windings

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between each other is at least partially, preferably completely, prevented.

The separation medium can be designed as a strip-shaped flat or curved web, in particular made of plastic.

Furthermore, synchronization means, in particular mechanical synchronization means, can be provided for synchronizing the rotational movement of the release media roll with that of the dispenser roll.

A safe and precise arrangement of the release medium can be achieved by providing a guide device with which the release medium can be fed to the dispenser roll.

A thermoplastic or a thermoset is advantageously used as a separating medium. Manufacturing advantages are achieved when it is extruded as a continuous strip.

An alternative embodiment of the invention according to claim 7 is based on a lifting and/or conveying device of the type mentioned, in which it is provided that the rope is provided with a separating medium so that when the rope is wound onto the dispenser roll, it gets between the individual rope windings of the rope on the dispenser roll in such a way that contact between the rope windings is at least partially, preferably completely, prevented.

In contrast to the aforementioned design, here the rope itself is provided with the separation medium, so that the desired effect of spacing the individual rope windings on the dispenser roll is equally ensured.

The separation medium can completely envelop the rope; however, it can also be provided that the separation medium only envelops the rope over a predetermined circumferential area.

The proposed measures ensure that the rope is treated very gently when it is wound onto the dispenser reel and later

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is unwound from it again. This reliably prevents micro-welding at specific points, which would damage the rope. This significantly extends the service life of the rope; this can happen by up to a factor of 50.
5

The drawing shows embodiments of the invention.

FIG 1 shows a schematic side view of a crane;
FIG 2 the section AB according to FIG 1 through the dispenser roll of the crane and

FIG 3 shows the left end area of the crane according to FIG 1 in an alternative embodiment.

FIG 1 shows a schematic side view of a crane 1. It has a vertically arranged support 9 in the usual way, to which a horizontally arranged support 10 is attached. A load 11 is attached to a wire rope 2 and is moved vertically up and down by winding and unwinding the wire rope 2 on a dispenser roll 3. Not shown are electrical drive means which rotate the dispenser roll 3 at a predetermined rotational speed and predetermined rotational angle.

In addition to the dispenser roll 3, another roll, namely the release medium roll 6, is arranged on the carrier 10. A release medium 4 is wound onto this, which is an endlessly extruded, flat plastic sheet. In principle, any type of plastic can be used as the material for the release medium, although a plastic manufactured by the company E-lastogran with the trade name Elastollan has proven particularly effective.

If the load 11 is to be moved vertically upwards, the wire rope 2 must be wound up onto the dispenser roll 3 accordingly. In this case, it is intended that during this winding process the strip-shaped separating medium 4 is introduced between the individual rope windings of the wire rope 2 on the dispenser roll 3 in such a way that contact between the individual rope windings is prevented.

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To illustrate this, FIG 2 shows the section A-B according to FIG 1. It can be seen how individual cable windings 5, 5', 5" of the wire cable 2 are wound onto the dispenser roll 3. The plastic sheet (separation medium 4) wound onto the separating medium roll 6 is guided under the cable 2 when the cable 2 is wound onto the dispenser roll 3 in such a way that, when wound onto the dispenser roll 3, it rests against the cable 2 in a semicircular shape from below. As can be seen from FIG 2, this means that the individual cable windings 5, 5', 5" of the cable 2 no longer have any direct - metallic - contact, since the separating medium 4 is located between the individual cable windings 5, 5', 5". Spot welding of the individual cable windings to one another is thus reliably prevented; the service life of the cable 2 is significantly increased.

As can be seen from FIG 3, it can be provided that the strip-shaped separating medium 4 is guided from its separating medium roll 6 over a guide device 8 when the rope 2 is wound onto the dispenser roll 3. This is only indicated schematically in FIG 3 and has the effect that the plastic strip 4 is brought exactly "under" the rope 2 when the rope 2 is wound onto the dispenser roll 3, so that when it is wound onto the dispenser roll 3 - as can be seen in FIG 2 - it wraps around the rope 2 in a semicircle.

While the plastic strip 4 is unwound from the release media roll 6 when the rope 2 is rolled up onto the dispenser roll 3, this process is reversed when the rope 2 is unrolled from the dispenser roll 3. In this case, the plastic strip 4 is wound back onto the release media roll 6.

It is important for the explained method to function properly that the separating medium 4 in the form of the plastic strip is guided under the rope 2 near the dispenser roll 3 at exactly the speed at which it is wound onto the dispenser roll 3. For this purpose, as can be seen in FIG 1, only very schematically shown synchronization means 7 are provided. These can be mechanical gear means that ensure that the separating medium 4 is fed at exactly the winding speed of the rope 2.

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However, it is also possible to implement the synchronization means 7 electronically. In this case, the separating media roll 6 can be driven by an electric motor, preferably by a servo motor, which receives its angle of rotation or rotation speed signals from a distance or speed measuring sensor, which measures the position or speed of the rope 2 when the rope 2 is rolled up onto the dispenser roll 3.

Metallic contact between the individual cable windings 5, 5', 5" of the cable 2 can also be prevented by providing the cable 2 with a separating medium 4 from the outset, at least in the area to be wound up. Here too, the plastic mentioned is preferably used, in which case the cable has the coating over at least part of its circumference. The cable 2 can be surrounded by the separating medium 4 in a semicircular manner, as can be seen in FIG. 2, which, if the cable is guided accordingly, is sufficient to ensure that the individual cable windings 5, 5', 5" are spaced apart when wound up.

Likewise, the rope 2 can also be completely surrounded by a plastic layer 4 so that the desired effect is achieved.
20

The proposal according to the invention can be used wherever steel cables have to be wound up and unwound in lifting and/or conveying devices, i.e. in all types of cranes, crane trucks, winches, etc.

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List of reference symbols

1 Lifting and/or conveying device (crane) 2 Rope (wire rope) 3 Donor roll 4 Separation medium 5.5·, 5" Rope winding 6 Release media roll 7 Synchronization means 8th Guide device 9 carrier 10 carrier 11 load

Claims (10)

1. Lifting and/or conveying device ( 1 ), in particular a crane, which has at least one rope ( 2 ), in particular a wire rope, and a dispenser roll ( 3 ) on which the rope ( 2 ) can be wound up or unwound, characterized in that the dispenser roll ( 3 ) is assigned a separating medium roll ( 6 ), from which, when the rope ( 2 ) is wound up onto the dispenser roll ( 3 ), a separating medium ( 4 ) is unwound between the individual rope windings ( 5 , 5 ', 5 ", . . .) of the rope ( 2 ) on the dispenser roll ( 3 ) in such a way that contact between the rope windings ( 5 , 5 ', 5 ", . . .) is at least partially, preferably completely, prevented. 2. Lifting and/or conveying device according to claim 1, characterized in that the separating medium ( 4 ) is designed as a strip-shaped flat or curved web, in particular made of plastic. 3. Lifting and/or conveying device according to claim 1 or 2, characterized by synchronization means ( 7 ), in particular mechanical synchronization means, for synchronizing the rotational movement of the release media roll ( 6 ) with that of the dispenser roll ( 3 ). 4. Lifting and/or conveying device according to one of claims 1 to 3, characterized by a guide device ( 8 ) with which the separating medium ( 4 ) is fed to the dispenser roll ( 3 ). 5. Lifting and/or conveying device according to one of claims 1 to 4, characterized in that the separating medium ( 4 ) is a thermoplastic or a duroplastic. 6. Lifting and/or conveying device according to claim 4 or claim 5, characterized in that the separating medium ( 4 ) is extruded as a continuous strip. 7. Lifting and/or conveying device ( 1 ), in particular a crane, which has at least one rope ( 2 ), in particular a wire rope, and a dispenser roll ( 3 ) on which the rope ( 2 ) can be wound up or unwound, characterized in that the rope ( 2 ) is provided with a separating medium ( 4 ) so that when the rope ( 2 ) is wound up onto the dispenser roll ( 3 ), it gets between the individual rope windings ( 5 , 5 ', 5 ", . . .) of the rope ( 2 ) on the dispenser roll ( 3 ) in such a way that contact between the rope windings ( 5 , 5 ', 5 ", . . .) is at least partially, preferably completely, prevented. 8. Lifting and/or conveying device according to claim 7, characterized in that the separating medium ( 4 ) completely envelops the rope ( 2 ). 9. Lifting and/or conveying device according to claim 7, characterized in that the separating medium ( 4 ) surrounds the rope ( 2 ) only over a predetermined circumferential area. 10. Lifting and/or conveying device according to one of claims 1 to 9, characterized in that the separating medium ( 4 ) consists of plastic, in particular of thermoplastic or duroplastic.