WO2004078577A1

WO2004078577A1 - A method and a device for increasing the stretch of a winch wire beyond the pulling capacity of the winch

Info

Publication number: WO2004078577A1
Application number: PCT/NO2004/000052
Authority: WO
Inventors: Arne Stokkeland
Original assignee: Brødr. Bauer-Nilsen As
Priority date: 2003-03-07
Filing date: 2004-02-26
Publication date: 2004-09-16
Also published as: NO20031051L; NO20031051D0; NO324628B1

Abstract

A method and a device for increasing the tension in the winch wire (6) of a vessel (1) beyond the pulling capacity of a winch (2), wherein an auxiliary actuator (4) is connected to the winch wire (6), the auxiliary actuator (4) being arranged to exert a tensile force in the winch wire (6) together with the winch (2).

Description

A METHOD AND A DEVICE FOR INCREASING THE STRETCH OF A WINCH WIRE BEYOND THE PULLING CAPACITY OF THE WINCH

This invention regards a method of increasing the stretch or tension of a winch wire beyond the pulling capacity of the winch. More particularly, it concerns a method in which an auxiliary actuator is connected to and pulls the winch wire when the loading on the winch wire exceeds the pulling capacity of the winch. The invention also comprises a device for implementing the invention.

In this context, winch wire means any form of long element, which can be used as a load-bearing element and wound on a winch.

In the course of e.g. offshore operations that involve the use of a vessel-mounted winch, a relatively high tension in the winch wire will sometimes be required. This is well known from the operation of anchor handling boats, where it must be possible to pull relatively heavy anchors free of the seabed.

Operations of the type that calls for an extra high tension in the winch wire only make up a small fraction of the work of an anchor handling boat, but the vessel must still be equipped with a winch dimensioned for these relatively infrequent operations .

The costs associated with the purchase and operation of the winch increase substantially when the winching power has to be increased. A large winch will also take up more space than a small winch.

The object of the invention is to remedy the disadvantages of prior art .

The object is achieved in accordance with the invention, by the characteristics stated in the description below and in the accompanying claims.

By equipping a vessel with an auxiliary actuator arranged to grip the winch wire and pull with a force of the same order as the pulling capacity of the winch, the total pulling capacity of the winch wire may be increased significantly upon demand.

Thus it is possible to equip e.g. an anchor handling boat with a winch of sufficient pulling capacity to raise an anchor but not free the anchor from the seabed.

When freeing e.g. an anchor from the seabed, the auxiliary actuator is connected to the winch wire, whereupon the winch and the auxiliary actuator together exert sufficient pull on the winch wire to free the anchor. The auxiliary actuator is then released from the winch wire, whereupon the winch can raise the anchor.

When using a wire rope as a winch wire, connecting the actuator to the winch wire in a secure manner without damaging the winch wire can be problematic . According to the invention, the wire is clamped between two jaws/chucks of a wire clamp, of which one jaw can be displaced in and out from the wire and be pretensioned by means of unround, preferably elongated elements that roll against each other.

In an alternative embodiment, the wire clamp is provided with a wedge shaped chuck arranged to be drawn into the wire clamp when the actuator exerts a tensile force on the wire.

The following describes a non-limiting example of a preferred method and embodiment illustrated in the accompanying drawings, in which:

Figure 1 is a plan view of a vessel equipped with a winch, wherein there is provided an auxiliary actuator;

Figure 2 is an enlarged plan view of a wire clamp according to the invention;

Figure 3 is a side view of the wire clamp of figure 2 in an open position;

Figure 4 shows the same as figure 3 but here the wire clamp is closed; and

Figure 5 shows an alternative embodiment in which the wire clamp of figure 2 is provided with a wedge-shaped chuck.

In the drawings reference number 1 denotes a vessel equipped with a winch 2 and an auxiliary actuator 4. A winch wire 6 is wound partway on the winch 2 and runs over the aft end 8 of the vessel 1. The auxiliary actuator 4, which comprises two hydraulic cylinders 10, is connected to the base 12 of the winch 2. The piston rods 14 of the hydraulic cylinders 10 are connected to a wire clamp 16 that can be connected around the winch wire 6.

The wire clamp 16 comprises a clamping body 20 connected in an articulated manner to the piston rods 14 by means of hinge pins 22, a fixed chuck 24 and a gripping jaw 26. The gripping jaw 26 is arranged to press the winch wire 6 against the fixed chuck 24 by means of two unround bodies 28, 28'.

The unround bodies 28, 28' extend in parallel in a cutout 30 in the clamping body 20 and are arranged to be rotated about their longitudinal axes, between an inactive position in which the unround bodies 28, 28' abut each other at their smaller radius, and an active clamping position in which the unround bodies 28, 28' abut each other along their greater radius .

When the unround bodies 28, 28' roll and press against each other and against the clamping body 20 and the displaceable gripping jaw 26, respectively, a relatively large clamping force is exerted against the winch wire 6 when the unround bodies 28, 28' are rotated to their active position and have gained a turning moment .

A rotary actuator 32 is hinged to the unround bodies 28, 28' by means of levers 34, 34' and is arranged to rotate the unround bodies 28, 28' about their respective longitudinal

Θ.XΘS •

In an alternative embodiment, the wire clamp 16 is provided with a wedge-shaped chuck 36 to replace the fixed chuck 24, wherein the wedge-shaped chuck 36 is arranged to be pulled into the clamping body 20 by the winch wire 6 when the winch wire 6 in a loaded state tries to shift in the wire clamp 16 and the wire clamp 16 is in engagement with the wire winch 6.

Claims

C l a i m s

1. A method of increasing the tension in the winch wire (6) of a vessel (1) beyond the pulling capacity of a winch (2), c h a r a c t e r i z e d i n that an auxiliary actuator (4) is connected to the winch wire (6) between the winch (2) and the free end portion of the winch wire (6), the auxiliary actuator (4) being arranged to exert a tensile force in the winch wire (6) together with the winch (2) .

2. A method in accordance with Claim 1, c h a r a c t e r i z e d i n that the auxiliary actuator is connected to the winch wire (6) by means of a wire clamp (16) .

3. A wire clamp device (16) comprising a clamping body (20) and a displaceable gripping jaw (26) , c h a r a c t e r i z e d i n that two unround bodies (28, 28') that roll against each other and against the clamping body (20) and the displaceable jaw (26) , respectively, optionally via intermediate parts, clampingly abut the displaceable jaw (26) when in the active position, the mutual abutment between the unround bodies (28, 28') and against the clamping body (20) and the displaceable jaw (26) , respectively, being in the form of a line contact which is substantially parallel to the longitudinal axes of the unround bodies (28, 28') .

4. A device in accordance with Claim 3, c h a r a c t e r i z e d i n that the wire clamp (16) is connected to the auxiliary actuator (4) .

5. A device in accordance with Claim 3, c h a r a c t e r i z e d i n that the unround bodies (28, 28') are connected to a rotary actuator (32) by means of levers (34, 34').

6. A device in accordance with Claim 3 , c h a r a c t e r i z e d i n that the wire clamp (16) is provided with a wedge-shaped chuck (36) arranged to be pulled into the clamping body (20) by means of the winch wire ( 6) .