GB2311269A

GB2311269A - A device for applying tension load to a wire-rope

Info

Publication number: GB2311269A
Application number: GB9618866A
Authority: GB
Inventors: Seiji Kimura
Original assignee: DAITO JUKI KOJI CO Ltd
Current assignee: DAITO JUKI KOJI CO Ltd
Priority date: 1996-03-18
Filing date: 1996-09-10
Publication date: 1997-09-24
Also published as: DE19636726C2; JPH09255287A; GB9618866D0; DE19636726A1; JP4030024B2; FR2746085A1

Description

2311269

TITLE OF THE INVENTION

A device for applying tension load to a wire-rope BACKGROUND OF THE INVENTION FIELD OF THE INVENTION

This invention relates to a device for applying tension load to a new wire-rope that is to be wind-transferred to a winch of the crane. DESCRIPTION OF THE PRIOR ART

For wind-transferring a new wire-rope onto a winch of the crane, a new wire-rope wound on a wooden drum is unwound and used.

The work involves, fixing an end of the new wire-rope that is wound on a wooden drum to the winch onto which the wire-rope is to be windtransferred, and rotating the winch while applying a braking force to the wooden drum. However, it is necessary to apply a tension load to the wirerope to account for an initial stretching of the wire-rope so that the wire-rope can be tightly wound on the winch, and also for preventing a twisting of the wire-rope. Therefore, while wind-transferring a wire-rope to a winch, tension load is applied and the wire-rope is systematically wound on the winch.

For example, for thick wire-ropes like those having a diameter of 30mm, a tension load of more than 1 Ot is required.

In the prior art, because the applied tension load pulls the wire-rope with a great force and a strong braking force is applied to the wooden drum, the wire-rope being pulled squeezes in between the wire-ropes of the bottom layers of the wooden drum and damages the wire-rope there. In a worst case, the wire-rope squeezes so deeply that it becomes impossible to unwind the wire-rope from the wooden drum.

Moreover, because the applied tension load pulls the wire-rope with a great force and a strong braking force is applied to the wooden drum, the wooden drum sometimes breaks and it becomes impossible to unwind the wirerope from the wooden drum.

Furthermore, in order to overcome the above problems, enough tension load cannot be applied to wire-rope, and the wire-rope can not be tightly wound on the winch.

SUMMARY OF THE INVENTION

The present invention provides a device for applying tension load to a wire-rope, which acts as a go-between a drum on which a new wire-rope is wound and a winding means on which said wire-rope is to be wind transferred, comprising; an outer cylindrical means anchored unrotatably and having a spiral groove on its inner surface, said spiral groove having an inlet through which said wire-rope is inserted and an outlet through which said wire-rope is let out; an inner cylindrical means that rotatably fits inside said outer cylindrical means and; a rotation control means for controlling the rotation of said inner cylindrical means.

BRIEF DECRIPTIONS OF THE DRAWINGS Fig. 1 is a full explanatory view of an embodiment of the present invention.

Fig. 2 is a partial sectional view of an embodiment of the present invention.

Fig. 3 is a dismantled view of an embodiment of the present invention. Fig. 4 is a perspective sectional view of the outer cylinder Fig. 5 is an explanatory sectional view of the suppress roller. Fig 6 is an explanatory sectional view of a conical outer cylinder. Fig. 7 is an explanatory sectional view of an uneven conical outer cylinder. Fig. 8 is an explanatory sectional view of a conical outer cylinder having a body that is narrower in the central part.

SPECIFIC DESCRIPTION OF THE EMBODIMENT

Preferred embodiments of the present invention are described using the figures.

Fig. 1 is a full explanatory view, Fig. 2 is a partial sectional view, Fig. 3 is a dismantled view of an embodiment of the present invention, Fig. 4 is a perspective sectional view of the outer cylinder. In these figures, reference numeral 2 is a rotating table that holds a wooden drum 1 in a rotation possible manner. The rotating table 2 is driven by a rotation control device.

Reference numeral 3 is a wire-rope wound around the wooden drum 1.

Reference numeral 5 is a control drum formed by assembling an inner cylinder 6 and an outer cylinder 7.

The inner cylinder 6 is a both ends closed cylindrical body having an axle 8 at its center. The inner cylinder 6 has a stopper flange 9 at one of its ends, and a brake body 10 like a brake disc or a brake shoe at one or both the ends.

The outer cylinder 7 has a bore such that, the inner cylinder 6 fits inside and is covered by it. On the inner surface of the outer cylinder 7 a spiral groove 12 is formed by arranging a plurality of spiral plates 11. An inlet 13 and an outlet 14 is provided to the outer cylinder 7 for inserting the wire-rope 3 in the spiral groove 12.

The inner cylinder 6 is inserted in the outer cylinder 7 and a stopper flange 15 is fixed to the inner cylinder 6, thereby holding the outer cylinder 7 in between the stopper flanges 9 and 15 of the inner cylinder 6.

Incidentally, the gap between the outer surface of the inner cylinder 6 and spiral plates 11 of the outer cylinder 7 is such that the wire-rope 3 may not pass through it.

Then, the axle 8 of the inner cylinder 6 is made to rest on a stand 16, the brake body 10 is connected to a rotation control device and the outer cylinder 7 is fixed tightly to the main body of the device with the help of stopper 17.

In the so assembled control drum 5, the wire-rope 3 from the wooden drum 1, guided by the wire-guide 18, is inserted and pushed through the inlet 13, wound on the outer surface of the inner cylinder 6 along the spiral grove 12, let out through the outlet 14 and fixed to a winch of the crane.

Thereafter, the winch is rotated and the wire-rope 3 is then windtransferred to the winch. However, while doing this, braking force is applied to the wooden drum 1 and also to the brake body 10 of the inner cylinder 6 in such a way that the pulling force A exerted by the wooden drum 1 on the wire-rope 3 is less than the pulling force B exerted by the winch on the same. Because of this, the control drum 5 absorbs all the pulling force of the winch and does not transfer it to the wooden drum 1.

This can be achieved by applying a proper brake to the inner cylinder 6 of the control drum 5, due to which a primary frictional force develops because of a firm contact of the wire-rope 3 with the inner cylinder 6.

Furthermore, though the wire-rope 3 passes inside the control drum 5 successively and smoothly on basis of the principle of the screw, there develops a secondary frictional force because of a firm contact of the wire-rope 3 with the spiral plates 11.

The primary and the secondary frictional force acts as a tension load against the pulling force of the winch, due to which it becomes possible to successively, smoothly and tightly wind-transfer the wire-rope to the winch. Besides, since the pulling force of the winch is not conveyed to the wooden drum 1 because of the presence of control drum 5, the wirerope 3 does not squeeze in between the wire-ropes of the bottom layers of the wooden drum 1.

The breaking capacity of inner cylinder 6 of the control drum 5, the number of turns of the wire-rope 3 wound on the inner cylinder 6 and the length of the wire-rope in contact with the spiral plates 11 of the outer cylinder 7 are the prime factors that decide the breaking effect due to the control drum 5 on the wire-rope 3.

As shown in Fig. 1 and Fig. 5, to bring the wire-rope 3 in direct contact with the outer surface of the inner cylinder 6, if necessary, suppress roller 19 can provided in between the inlet 13 of the outer cylinder 7 and the spiral groove 12. Since the suppress roller 19 presses down the wire-rope 3 against the outer surface of the inner cylinder 6, even if the speed at which the wire-rope 3 is unwound from the wooden drum 1 changes, the wire-rope 3 is wound on the inner cylinder 6 at a constant speed.

As shown in Fig. 5, for establishing the suppress roller 19, a part of the suppress roller 19 is made to project through an opening 20 in the outer cylinder 7 and the suppress roller lgis held in this position by a support arm 21. One end of the support arm 21 is fixed to the outer cylinder 7 in a movement possible manner and the other end is pressed by a pressing tool 22. The force at which the suppress roller 19 is to be pressed against the inner cylinder 6 can be adjusted by loosening or tightening the pressing tool 22.

In the control drum 5 explained above, the inner cylinder 6 and the outer cylinder 7 are of equal lengths, however, they could be of unequal lengths. Furthermore, as shown in Fig. 6, the outer cylinder 7 could be of a conical shape, and the shape of the inner cylinder 6 adjusted accordingly.

Again, as shown in Fig. 7, the outer cylinder 7 could be of an uneven conical shape, and the shape of the inner cylinder 6 adjusted accordingly.

Furthermore, the outer cylinder 7 explained above is a single body, however, the outer cylinder 7 could be a dividable body formed by assembling a plurality of parts that are divided along the axis of said outer cylinder as shown in Fig. 4. In such a case a hinge is provided at one end of each of the parts so that the parts can be coupled in a movement possible fashion, and the other end of the parts secured firmly. By adopting such a dividable structure for the outer cylinder 7, an open/close state of the outer cylinder 7 can be achieved, due to which the installation on the inner cylinder 6 becomes easy, and the outer cylinder 7 can be easily installed on an inner cylinder 6 even if the later has an uneven conical shape.

-6 Furthermore, as shown in Fig. 8, a control drum 5 having an inner cylinder which is narrower in the central part than at the ends and in which an outer cylinder is not used can be provided.

In such a control drum which is narrower in the central part than at the ends, since the wire-rope is wound by applying a proper brake to the control drum 5 the friction between the outer surface of the control drum 5 and the wire increases, and since the central part is narrower, due to the pulling force from the winch the turns of the wire-rope 3 wound on the control drum 5 gather at the central part of the control drum 5 and make a firm contact with each other generating a braking effect.

The breaking capacity of control drum 5 and the number of turns of the wire-rope 3 wound on the inner cylinder 6 are the prime factors that decide the breaking effect due to the control drum 5 on the wire-rope 3.

Thus, since the pulling force of the winch can be controPed by the control drum 5 so that a strong pulling force of the winch is not conveyed to the wire-rope 3 behind the control drum 5, the wire-rope 3 does not squeeze in between the wire-ropes of the bottom layers of the wooden drum 1.

In the above, a case in which a wire-rope is wind-transferred to a winch of a crane is explained, however, the invention is not limited to a winch, a wire-rope wound on a wooden drum could be wind-transferred on -a device other than a winch.

According to the present invention, an outer cylindrical means anchored unrotatably and having a spiral groove on its inner surface holds an inner cylindrical means rotatably and a wire-rope inserted through the inlet and wound on the inner cylinder generates a tension load because of the frictional force developed by a contact with the outer surface of the inner cylinder and also with the walls of the spiral groove, thereby letting out the wire- rope through the outlet from which the initial stretching is removed.

Therefore, it becomes possible to successively, smoothly and tightly windtransfer the wire-rope to a winch or like.

Furthermore, the wire-rope does not squeeze in between the wire-ropes of the bottom layers of the winch even if a great tension load is exerted by the winch on the wire-rope being wind-transferred.

Also, since the pulling force due to the winch is not conveyed to the Wooden drum, even if a great pulling force acts on the wire-rope that is being unwound from the wooden drum, neither the wire-rope squeezes in between the wire-ropes of the bottom layers of the wooden drum nor it sticks to the wire-ropes of the bottom layers of the drum.

-8

Claims

A device for applying tension load to a wire-rope (3), which acts as a gobetween a drum (1) on which a new wire-rope (3) is wound and a winding means on which said wire-rope (3) is to be Wind-transferred, comprising: an outer cylindrical means (7) anchored unrotatably and having a spiral groove (12) on its inner surface, said spiral groove (12) having an inlet (13) through which said wire-rope (3) is inserted and an outlet (14) through which said wire-rope (3) is let out; an inner cylindrical means (6) that rotatably fits inside said outer cylindrical means (7) and; a rotation control means for controlling the rotation of said inner cylindrical means (6).
A device for applying tension load to a wire-rope (3) according to claim 1 such that, said spiral groove (12) is formed by arranging a plurality of spiral plates (11) on the inner surface of said outer cylindrical means (7).
3. A device for applying tension load to a wire-rope (3) according to claim 1 and claim 2 such that; said outer cylindrical means (7) is formed by joining parts divided along the axis of said outer cylindrical means(7).
4. A device for applying tension load to a wire-rope (3) according to any of the claim 1 to claim 2 such that; a suppress roller (19) is provided in said spiral groove (12) for controlling the winding speed of said wire-rope (3).
5. A device for applying tension load to a wire-rope (3), which acts as a go-between a drum (1) on which a new wire-rope (3) is wound and a winding means -9- on which said wire-rope (3) is to be wind-transferred, comprising:

a cylindrical means (5) having a body that gradually becomes narrower in the central part from the two ends and:

a rotation control means for controlling the rotation of said cylindrical means (5).
6. A device for applying tension load to a wire rope substantially as herein described with reference to the accompanying drawings.