WO2000027740A1

WO2000027740A1 - Load rotation device

Info

Publication number: WO2000027740A1
Application number: PCT/NO1999/000333
Authority: WO
Inventors: Svein Upsahl; Torbjørn HEGLUM; Håvard BUHAUG
Original assignee: Hydralift Asa
Priority date: 1998-11-05
Filing date: 1999-11-05
Publication date: 2000-05-18
Also published as: GB2358853B; NO311292B1; AU1298900A; NO985159D0; GB0109944D0; GB2358853A; NO985159L

Abstract

A load rotation device, mountable on a crane and comprising a slewing unit (6), comprises a telescope (5), the telescoping arm (5) being provided with the slewing unit (6) on its outer, distal end. A swivel hook block (14) is provided with engagement means (16) which mate with corresponding engagement means (7).

Description

Load rotation device

The present invention relates to a load rotation device of the kind mentioned in the introductory part of claim 1.

When lifting loads comprising long objects such as containers, pipes, bars, timber and the^" like, it is often necessary to rotate the load before lowering it into its new position. When lifting e.g. pipes on oil platforms or ships, the rotation of the load usually is carried out by crew members. Such pipes are heavy and may experience pendulum motions caused by rough seas or wind. Injuries or even death caused by squeezing is commonplace. Therefore, there has been a need for an automatic load rotation device which may be arranged on the tip of a jib or a pivot arm of a crane .

US Patent no. 5 125 707 discloses a rotary load lifting hook device in which the swivel hook block comprises a re- motely operable rotational driving device for rotation.

The swivel hook block is carried by a hoisting rope via a sheave pulley which somewhat limits unwanted rotation. When rotating the load, the rotational driving device is actuated to rotate the hook. However, due to the freely carried swivel hook block configuration, uncontrolled rotation and swinging of the load may easily occur and this arrangement is therefore not feasible on oil platforms and ships. Furthermore, if the crane comprises pivotable arms, the steel wire rope length will vary when pivoting the arms because the steel wire rope runs through one or more guiding wheels. For example, when the crane is brought to a extended position, the amount of steel wire rope hanging freely off the arm or jib will tend to increase. This, together with the possible uncontrollable swinging and rota- tion of the load at the end of the steel wire rope, makes this lifting arrangement unsuitable for use on e.g. oil platforms or ships which inevitably experience heaving and pitching motions. One object of the present invention is to provide an automatic load rotation device.

An other object of the present invention is to provide an automatic load rotation device which is suitable for use on e.g. oil platforms, ships or other vessels which experience heaving and pitching motions.

Yet an other object of the present invention is to provide an automatic load rotation device which is suitable for use on cranes with pivotable arms where the length of steel wire rope varies when extending or contracting the crane.

A further object of the present invention is to provide an automatic load rotation device where the rotating arrangement never is subjected to vertical strain in the form of lifting forces or forces arising from heaving and pitching motions .

A still further object of the present invention is to provide an automatic load rotation device which alleviates the need for a crew in the vicinity of the load, thereby ensuring crew safety and cost savings .

Yet a further object of the present invention is to provide an automatic load rotation device which increases the accuracy and efficiency of the load transferring operation.

These and other objects are achieved by a device characterized in the features mentioned in the characterizing clause of claim 1 and in the subsequent dependent claims .

The present invention will in the following be further elu- cidated in conjunction with the appended drawings, in which: fig. 1 shows a perspective view of an embodiment according to the present in a down position with the hook block lowered,

fig. 2 shows a perspective view of the embodiment of the present invention in fig. 1 in a down position with the hook block docked, and

fig. 3 shows a perspective view of the embodiment of the present invention in fig. 1 in a active position.

Fig. 1 shows a load rotation device 1 according to the present invention in a down position and a swivel hook block 14 lowered. The load rotation device 1 is mounted to the crane jib head or the outermost arm of a crane by means of mechanical connectors 10, such as brackets or the like, which are provided on a cross beam 2, the cross beam also comprising four wire guides 12. The load rotation device 1 comprises a pivotable, preferably rectangular upper tele- scope 3, which is connected to the cross beam 2 by means of a hinge pin 4. The upper telescope 3 receives a lower telescope 5 with a corresponding profile, the lower, distal end of which is provided with a slewing unit 6 comprising a motor 8 and a rotating means which provides an engagement organ in the form of a docking tooth-ring 7. The motor 8 drives the docking tooth-ring 7 via suitable gears (not shown) . The lower telescope 5 is telescopically received in the upper telescope 3 and is prevented from sliding out by means of suitable organs, e.g. pins or co-acting rims (not shown) . The upper telescope also comprises limit switches. The rectangular profile of the telescopically engaged arms provides a configuration which prevents tor- sional rotation of the two telescopes 3, 5 with respect to each other, but may also have any other suitable configura- tion. Thereby, the slewing unit 6 is also torsionally fixed. A steel wire rope 11 runs trough the load rotation device 1 and trough a center hole in the docking tooth-ring 7. The steel wire rope 11 is held in a centered position by means of four wire guides 12 provided on the cross beam 2 in the vicinity of the hinge pin 4, and four corresponding wire guides 13 provided on the lower telescope 5 in the vicinity of the slewing unit 6. The end of the steel wire rope 11 is provided with the swivel hook block 14 with a fixed hook 15. The upper surface of the swivel hook block 14 is configured to mate with the docking tooth-ring 7 and is provided with a tooth-ring 16. The swivel hook block 14 may be connected to the steel wire rope via a swivel (not shown) , allowing the swivel hook block 14 and hook 15 to rotate without twisting the steel wire rope 11.

The load 9 is picked up in a conventional manner by feeding out steel wire rope and bringing the hook to the load by positioning/extending/contracting the jib or arm of a crane above the load. After picking up the load 9, the load 9 is lifted by pulling in the steel wire rope until the tooth- ring 16 of the swivel hook block 14 docks with the docking tooth-ring 7 (fig. 2) . In order to ensure proper docking and sufficient vertical bearing force to prevent slipping between the docking tooth-ring 7 and tooth-ring 16, the swivel hook block 14 and load is further retracted, causing the slewing unit 6 and lower telescope 5 to retract telescopically, whereby the weight of the lower telescope 5 and slewing unit 6 rests on tooth-ring 16 of the swivel hook block 14 , maintaining the engagement between the docking tooth-ring 7 and tooth-ring 16 (fig. 3) . The orientation of the load 9 may be detected by means of sensors and one or more reference points on the docking tooth-ring 7 or may be visually decided by an operator. A position indicator, such as a tachometer, may also be provided, giving feedback about the position of the swivel hook block 14.

The load may be rotated as needed by activating the motor 8, which transmits a torque to the tooth-ring 16 via the docking tooth-ring 7. This torque rotates the entire swivel hook block 14 and load. The telescopically arranged device allows the crane extend or retract while maintaining the abutment force between the docking tooth-ring 7 and the tooth-ring 16 on the swivel hook block 14. Slack in the free steel wire rope may to a certain extent be picked up by the telescopic arrangement, by the telescoping action of the lower telescope 5. If necessary, detection organs (limit switches) may be provided on the telescopes 4 and/or 5. The detection organs communicate with the winch, whereupon the winch may regu- late the amount of free steel wire rope. In a preferred embodiment the lower telescope 5 is designed with a length that allows it to slide in or out about 500 mm or more. By engaging the docking tooth-ring 7 with the tooth-ring 16 on the swivel hook block 14 and retracting the swivel hook block 14 further, the lower telescope 5 slides into the upper telescope 3. This provides for play 17 in each direction when the rotation device 1 is in the active position. Usually, the length 17 of the telescopic action is not sufficient to pick up all of the relative vertical movement. When the telescope 5 has reached its outer or inner positions, determined by limit switches, the crane will stop and the winch will be activated and feed out or pull in steel wire rope . The crane may only be driven with the winch locked and the brakes engaged, whereby the winch only runs with the lower telescope 5 in a predetermined inner or outer position. The inner position of the telescope 5, determined by a limit switch, ensures sufficient play 17 to prevent the telescopes 3 and 5 from bottoming out and causing mechanical damage .

According to the invention the slewing unit 6 may be designed as a conventional system, that is, with a rotating disc, a gear box and a hydraulic motor. There are no cables or conduits to the slewing unit 6, and thereby no limitations on the rotation.

The load is placed at its final position with the swivel hook block 14 in the docked upper position. This limits swinging motions and prevents unwanted twisting of the load. The load rotation device is allowed to swing in one direction only, due to the hinge pin configuration, and is dimensioned to withstand possible stresses in the perpen- dicular direction. The load rotation device 1 thereby constitutes a substantially rigid suspension means, which is advantageous for rotating and positioning long, relatively heavy loads .

It will be understood that the aforementioned and illustrated preferred embodiment of the invention is solely a non-limiting example and that this embodiment may be varied in many ways within the scope of the accompanying claims .

Claims

C l a i s

1. A load rotation device, mountable on a crane and comprising a slewing unit (6) , c h a r a c t e r i z e d i n that it comprises a telescope (5) , the telescoping arm (5) being provided with the slewing unit (6) on its outer, distal end.

2. A load rotation device according to claim 1, c h a r a c t e r i z e d i n that a swivel hook block (14) is provided with engagement means (16) which mate with corresponding engagement means (7) provided on the slewing unit (6) .

3. A load rotation device according to claim 2, c h a r a c t e r i z e d i n that the telescope (5) must contract into a telescope (3) before the rotation operation begins .

4. A load rotation device according to claim 2 or 3 , c h a r a c t e r i z e d i n that some or all of the weight of the telescope (5) and the slewing unit (6) rests on the swivel hook block (14) , whereby a vertical force is provided which ensures engagement between the engagement means (7, 16) .

5. A load rotation device according to one of the previous claims, c h a r a c t e r i z e d i n that the telescopes (3, 5) are configured to prevent torsional movement.

6. A load rotation device according to one of the previous claims, c h a r a c t e r i z e d i n that the telescopes (3, 5) have a rectangular configuration.

7. A load rotation device according to one of the previous claims, c h a r a c t e r i z e d i n that a steel wire rope (11) is centered in the load rotation device (1) by means of wire guides (12) which are mounted on a cross beam (2) in the vicinity of a hinge pin (4) and corresponding wire guides (13) provided on the telescope (5) in the vicinity of the slewing unit (6) , and that the steel wire rope (11) runs trough a center hole in the engagement means (7) .

AMENDED CLAIMS

[received by the International Bureau on 14 April 2000 (14.04.00); original claims 1 and 2 replaced by new claim 1; original claims 3-7 amended and renumbered as claims 2-6 (2 pages)]

1. A load rotation device comprising a slewing unit (6) and at least one telescoping arm (5) , the slewing unit (6) being provided on the outer, distal end of the telescoping arm (5) , c h a r a c t e r i z e d i n that a steel wire rope (11) runs trough the at least one telescoping arm (5) and the slewing unit (6) , the end of the steel wire rope being provided with a swivel hook block (14) comprising engagement means (16) which mate with corresponding engagement means (7) on the slewing unit (6) , the respective engagement means (7, 16) engaging when the steel wire rope (11) with the swivel hook block (14) is pulled sufficiently far in.

2. A load rotation device according to claim 1, c h a r a c t e r i z e d i n that the at least one telescoping arm (5) must contract into a telescope (3) be- fore the rotation operation begins.

3. A load rotation device according to claim 2 , c h a r a c t e r i z e d i n that some or all of the weight of the at least one telescoping arm (5) and the slewing unit (6) rests on the swivel hook block (14) , whereby a vertical force is provided which ensures engagement between the engagement means (7, 16) .

4. A load rotation device according to one of the previous claims, c h a r a c t e r i z e d i n that the telescope (3) and at least one telescopic arm (5) are configured so as to prevent torsional movement.

5. A load rotation device according to one of the previous claims, c h a r a c t e r i z e d i n that the telescope (3) and at least one telescopic arm (5) have a rectangular configuration.

6. A load rotation device according to one of the previous claims, c h a r a c t e r i z e d i n that a steel wire rope (11) is centered in the load rotation device (1) by means of wire guides (12) which are mounted on a cross beam (2) in the vicinity of a hinge pin (4) and corresponding wire guides (13) provided on the at least one telescopic arm (5) in the vicinity of the slewing unit (6) , and that the steel wire rope (11) runs trough a center hole in the engagement means (7) .