Spreader bar for distributing a lifting force of a crane and method of using such a spreader bar

Patent metadata

Field	Value
Publication number	US-12017890-B2
Application number	US-202117918606-A
Country	US
Kind code	B2
Filing date	May 7, 2021
Priority date	May 14, 2020
Publication date	Jun 25, 2024
Grant date	Jun 25, 2024

Abstract

The invention relates to a spreader bar (1) for distributing a lifting force from a crane (2) onto a two lifting regions (3,4) f a load (5) to be lifted. The spreader bar comprises a frame (6) and first and second systems (7,8). Each system comprises a lifting pulley (9), a connector (10) for connecting the spreader bar to the respective lifting region via a main wire (11) guided by the lifting pulley, an actuator (15) for vertically moving the connector via an actuator wire (16), and a movably arranged suspension element (19) connecting the actuator wire and the main wire. A compensator (20) compensates for possible fluctuations in the vertical distance between the respective lifting region of the load and the spreader bar. Such fluctuations can be due to the crane or the load being located on a floating vessel. When the suspension element is engaged with a blocking element (23), the lifting force from the crane can be transferred to the main wire in order to lift the load.

First claim

The invention claimed is:

1. A spreader bar for distributing a lifting force from a crane onto a first lifting region and a second lifting region of a load to be lifted, the lifting regions being separated by a horizontal distance,
wherein the spreader bar has a frame and comprises a first system for applying a part of the lifting force to the first lifting region and a second system for applying another part of the lifting force to the second lifting region,
wherein each of the first and second systems comprises:
a lifting pulley arranged on the frame, so that a horizontal distance between the lifting pulleys of the first and second systems corresponds to the horizontal distance between the first and second lifting regions,
a connector for connecting the spreader bar to the respective lifting region via a main wire guided by the lifting pulley,
an actuator arranged on the frame for vertically moving the connector via an actuator wire,
a suspension element connecting the actuator wire and the main wire, and
a compensator mounted on the frame for acting on the actuator wire to compensate for possible fluctuations in the vertical distance between the respective lifting region of the load and the spreader bar and thereby ensure that the main wire and the actuator wire remain under tension after the connector has been connected to the load, and

wherein, for each of the first and second systems, the suspension element is movable along a support having a blocking element arranged at a predetermined position, so that when the suspension element is engaged with the blocking element, no further compensation will take place by the compensator, and the lifting force from the crane can be transferred to the main wire in order to lift the load.

2. The spreader bar according to claim 1 , wherein the frame of the spreader bar extends between a first end where the lifting pulley of the first system is arranged and a second end where the lifting pulley of the second system is arranged.

3. The spreader bar according to claim 1 , wherein the actuators are selected from a linear actuator, a winch, a pivotally arranged arm, or a combination thereof.

4. The spreader bar according to claim 1 , wherein the actuator wires are guided by guide pulleys.

5. The spreader bar according to claim 1 , wherein the actuators are adapted to function independently of each other.

6. The spreader bar according to claim 1 , wherein the actuators are remotely controlled.

7. The spreader bar according to claim 1 , wherein each of the compensators comprises one or more of the following: linear actuator, spring, pulley, or a piston.

8. The spreader bar according to claim 1 , wherein the compensators are adapted to function independently of each other.

9. The spreader bar according to claim 1 , wherein the spreader bar comprises:
first section extending from the first end to a central region, and the first system is arranged in the first section, and
a second section extending from the second end to the central region, and the second system is arranged in the second section.

10. The spreader bar according to claim 1 , wherein each of the connectors is provided with at least one sensor and at least one locking mechanism adapted for remote-controlled establishment of a secure connection between the connectors and the load to be lifted.

11. The spreader bar according to claim 1 , wherein the actuator and the compensator are included in one and the same system.

12. A method of lifting a load by using a crane with a spreader bar according to claim 1 , the method comprising the following steps:
arranging the spreader bar with the lifting pulley of the first system above the first lifting region of the load and the lifting pulley of the second system above the second lifting region,
for the first system, adjusting the vertical distance between the connector and the first lifting region by use of the actuator, and establishing the connection between the connector and the first lifting region,
for the second system, adjusting the vertical distance between the connector and the second lifting region by use of the actuator, and at the same time allowing the compensator of the first system to adjust the length of the actuator wire and main wire of the first system to maintain tension therein,
establishing the connection between the connector of the second system and the second lifting region,
lifting the spreader bar and at the same time for each of the first and second systems allowing the compensator to adjust the length of the actuator wire and main wire to maintain tension therein,
by continued lifting of the spreader bar, for each of the first and second systems allowing the suspension element to move along the support until it engages with the blocking element, and
by continued lifting of the spreader bar, also lifting the load.

13. The method according to claim 12 , wherein the actuators are adapted to function independently of each other.

14. The method according to claim 12 , wherein the actuators are remotely controlled.

15. The method according to claim 12 , wherein each of the connectors is provided with at least one sensor and at least one locking mechanism, and wherein secure connections between the connectors and the load to be lifted are established by remote control.

Assignees

• Vestas Wind Sys As

Inventors

• Botwright Adrian

Classifications

• Y02E10/72

  Wind turbines with rotation axis in wind direction · CPC title

• B66C13/02

  Devices for facilitating retrieval of floating objects, e.g. for recovering crafts from water (handling live-boats B63B; salvaging, or hauling-out on slipways, waterborne vessels B63C; winding mechanism controls B66D1/52) · CPC title

• B66C1/108 Primary

  for lifting parts of wind turbines · CPC title