Tie-Back System for Cranes, in Particular Heavy Load Offshore Cranes

• US 20080251484A1
• Filed: 09/06/2006
• Published: 10/16/2008
• Est. Priority Date: 09/06/2005
• Status: Active Grant

• Current Assignee: Gustomsc Resources B.V. (NOV, Inc.)
• Original Assignee: Gusto B.V.
• Inventors: Commandeur, Johan Albert, Woldring, Wilhelmus Coenradus Johannes Jozephus, van Marrewijk, Michael Franeiseus Maria
• Granted Patent: US 7,624,882 B2
• Time in Patent Office: Days
• US Class Current: 212/76
• CPC Class Codes: B66C 23/52 Floating cranes floating dredgers E02F
• CPC Class Codes: B66C 23/82 Luffing gear

Abstract

The invention relates to a tie-back system for a crane comprising a rotatable base with a generally vertical support frame and a lifting arm which is with a lower end hingedly connected to the base in a hinge point, an upper part of the frame carrying a displacement member movable relative to the frame, the displacement member carrying a first cable guide means, a first cable extending from a first connection point on the arm along the first cable guide means to a first pulling device.

The displacement member comprising a tie connection point for connection to a tie member, a second cable guide means attached to an upper part of the frame and a second cable extending from a second connection point on the arm along the second cable guide means to a second pulling device.

The frame comprising a stop part situated near the displacement member, wherein in a load transfer position the displacement member engages with the stop part for transferring a load on the first cable guide means to the frame, the displacement member in a tie-back position being disengaged from the stop part for transferring a load on the first cable guide means to a tie member which in the tie-back position is one side attached to a connection point at a distance from hinge point of the lifting arm, and on the other side to the tie connection point of the displacement member.

Claims

1. Crane comprising a rotatable base with a generally vertical support frame and a lifting arm which is with a lower end hingedly connected to the base in a hinge point, an upper part of the frame carrying a displacement member movable relative to the frame, the displacement member carrying a first cable guide means, a first cable extending from a first connection point on the arm along the first cable guide means to a first pulling device,

the displacement member comprising a tie connection point for connection to a tie member,

a second cable guide means attached to an upper part of the frame and a second cable extending from a second connection point on the arm along the second cable guide means to a second pulling device,

the frame comprising a stop part situated near the displacement member,

wherein in a load transfer position the displacement member engages with the stop part for transferring a load on the first cable guide means to the frame, the displacement member in a tie-back position being disengaged from the stop part for transferring a load on the first cable guide means to a tie member which in the tie-back position is one side attached to a connection point at a distance from hinge point of the lifting arm, and on the other side to the tie connection point of the displacement member.

2. Crane according to claim 1, wherein the displacement member comprises a substantially triangular body, with its apex point hingedly connected to the frame, and with the first cable guide means and the tie connection point being situated at or near respective corners along a base of the triangular body.

3. Crane according to claim 1 or 2, wherein the tie member comprises a first rod, hingedly connected to the tie connection point of the displacement member and a second rod, hingedly attached to the first rod and in a load transfer position substantially parallel to the first rod and in the tie-back position extending substantially in line with the first rod.

4. Crane according to claim 1 or 2, wherein the frame is substantially A-shaped with a first, substantially vertical leg carrying at its upper end the displacement member, and a second leg, at an angle with the first leg, and with an upper end connected to the upper end of the first leg, the second leg comprising the stop surface.

5. Crane according to claim 1 or 2, comprising at least two first cable guide means each attached to a respective displacement member, and at least two second cable guide means, each guiding a respective cable.

7. Crane according to claim 3, wherein the frame is substantially A-shaped with a first, substantially vertical leg carrying at its upper end the displacement member, and a second leg, at an angle with the first leg, and with an upper end connected to the upper end of the first leg, the second leg comprising the stop surface.

8. Crane according to claim 3, comprising at least two first cable guide means each attached to a respective displacement member, and at least two second cable guide means, each guiding a respective cable.

9. Crane according to claim 4, comprising at least two first cable guide means each attached to a respective displacement member, and at least two second cable guide means, each guiding a respective cable.

6. Method of attaching a crane lifting arm to a tie member, the crane comprising a rotatable base with a support frame and the lifting arm which is with a lower end hingedly connected to the base in a hinge point, an upper part of the frame carrying a displacement member movable relative to the frame, the displacement member carrying a first cable guide means, a first cable extending from a first connection point on the arm along the first cable guide means to a first pulling device,

the displacement member comprising a tie connection point for connection to a tie member,

a second cable guide means attached to the upper part of the frame and a second cable extending from a second connection point on the arm along the second cable guide means to a second pulling device, comprising the steps of:

placing a load on the second cable

slackening of the first cable such that the displacement member can move away from a stop part on the frame,

attaching a tie member with one end to an attachment point at or near the height of the base, at a distance from the hinge point, which tie member with its other end is connected to the attachment member, and

placing a load on the first cable while maintaining the displacement member at a distance from the stop part.