GB2181712A

GB2181712A - Lifting device

Info

Publication number: GB2181712A
Application number: GB08525547A
Authority: GB
Inventors: G H Williams; S D W Dowling
Original assignee: HANDLING CONSULTANTS Ltd
Current assignee: HANDLING CONSULTANTS Ltd
Priority date: 1985-10-17
Filing date: 1985-10-17
Publication date: 1987-04-29
Also published as: GB8525547D0

Abstract

A lifting device, for releasably suspending loads from a crane in such a way as to permit the hook H to be situated vertically above the load L by only a small working clearance. The hook engages a releasable pin 1 located with an assembly of beams 2, beams 4 sliding within the assembly and 32 supporting saddles 7 which engage within a central aperture of the load. The beams 4 can slide into and out from the assembly by rack and pinions to enable the saddles to engage and disengage the load. Relative rotation between a block B and assembly 2 allows the load to be slewed. <IMAGE>

Description

SPECIFICATION Releasable device for suspending loads This invention relates to a releasable device for sus- pending loads from a crane or similar lifting equipment.

There exists a wide range of different types of attachments which are used suspended from the hook of a crane or similar equipment to facilitate the sequence of handling loads typically consisting of grabbing the load, lifting, transporting, lowering and releasing the load.

In particularthere are two distincttypes of grab, designed forthe lifting of coils of sheet steel with the coil axis horizontal. The firsttype of grab relies upon a number of links arranged to form two parallelograms. The action ofthe parallelogram linkages permits movementto grab or release a range of sizes of coil. The second type of grab relies upon a pair of horizontal sliding members to produce a telescopic action, whereby coils of differentsizes may be grabbed or released.The second type of design typically has a smallervertical distance between the crane hookandthe load coil than thefirsttype. Nonetheless the vertical distance between the crane hook and the load rernains large and, as a result,these grabs cannot lift coils to great heights in buildings where the lift height ofthe crane is limited. In orderto carry out such lifts it may be necessaryto dismount the grab and resort two inconvenient manual slinging of the load. Considerable operational advantages could be realised if a coil grab could be made with a very small vertical distance between the hook ofthe crane and the load coil.

According to the present invention there is provided a releasable device for handling loads in conjunction with a crane orsimilarequipmentwhereby the elements of the device are arranged so that a hook of the crane may be situated vertically above and adjacent to the load, comprising a main framework having at or near its center a space adapted to receive the hook of the associated crane thus ensuring that the lower surface ofthe hook is above the top surface of the load by only a small working clearance, the main framework also having a number of holes which co-operate with a connecting pin, permitting the connecting pin to move axially thus enabling a releasable connection forthe hook, a number of sliding bearingsfixed to the mainframework, upon which slide a number of pairs of sliding beams, a numberofstructural membersforming an end frame structure which unites each pairofsliding beams one tothe other, a numberoffinger like projections per- manently attached to the end frame structure, a number of saddles releasably attached to the finger like projections to co-operate with the load, a power and drive system to drive the sliding beams overthe desired range enabling the grabbing or releasing of coils ofvarious sizes, a bridle rotatably attached to the main frame and shaped to fit around a pulley block of the associated crane, in such a way as to permit the transmission oftorque, a power and drive system to rotate the bridle with respect to the main frame, this slewing drive system being required to transmit slewing torque only, the lifting load being carried by a bearing between the hook and the pulley block of the associated crane.

A specific embodiment of the invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 shows a side view of the lifter with a load coil and the ropes, block and hook of the associated crane.

Figure2 shows an end view of the lifter with a load coil and the ropes, block and hook of the associated crane.

Figure 3 shows a plan view of the lifter with the ropes and block of the associated crane.

Figure 4shows in perspective the lifter without a load coil, suspended from the ropes, block and hook of the associated crane.

Referring to the figures the lifting device comprises a releaseable pin 1 which passes through holes 8 in the centre beams 9 of the main frame 2. The pin 1 maybe moved axially using the handle 10, to permit release from or engagement to the hook H, of the associated crane. Permanently attached to the central beams 9 are upper end beams 11 and lower end beams 12. Permanently attached to the upper end beams 11 and the lower end beams 12 are side beams 13. Permanently attached to the side beams 13 and the centre beams 9 are the upper bearing support beams 14 and the lower bearing support beams 15. Attached to these beams 11,12,14, 15 are replaceable plain bearings 16. Between the upper and lowerbearingsareslidablymounted a numberof sliding beams 4.These sliding beams are joined in pairs by end frame members 5,to which arefixed fingers 6 projecting inwards. Upon this finger is mounted a replaceable saddle 7 which engages with the bore ofthe load L.

In order to control the movement of the saddles 7, so that they may engage or disengage with the bore of loads L of different sizes, the sliding beams 4 have fixed to their inner surfaces a toothed rack 19 which engages with a gear20,which is in turn driven by shaft 21. Shaft 21 is driven by the electric motor/ gearbox unit 25 via the bevel gearboxes 22 and shafts 24.

The hook H ofthe associated crane is rotatablyfree but axially restrained on the hook swivel bearing Sin the block B which is supported on ropes R. The lifting device is made to slew by causing relative rotation between the block Band the main frame 2, while the vertical load is carried on the hook swivel bearing S.

The bridle 33 has cut into itan approximately rectangu lar hole 35 wh ich co-operateswiththeblockB to transmit the torque reaction associated with the slewing motion. Attached to the bridle 33 is an electric motor/gearbox unit 32 which drives a gear 30 which in turn meshes with a large ring gear29. This ring gear is in turn attached to the main frame 2. The bridle is constrained to rotate co-axiallywith the hook swivel bearing and restrained axially by a number of bearings 34.

1. Areleasabledeviceforhandling loads in con

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Releasable device for suspending loads This invention relates to a releasable device for sus- pending loads from a crane or similar lifting equipment. There exists a wide range of different types of attachments which are used suspended from the hook of a crane or similar equipment to facilitate the sequence of handling loads typically consisting of grabbing the load, lifting, transporting, lowering and releasing the load. In particularthere are two distincttypes of grab, designed forthe lifting of coils of sheet steel with the coil axis horizontal. The firsttype of grab relies upon a number of links arranged to form two parallelograms. The action ofthe parallelogram linkages permits movementto grab or release a range of sizes of coil. The second type of grab relies upon a pair of horizontal sliding members to produce a telescopic action, whereby coils of differentsizes may be grabbed or released.The second type of design typically has a smallervertical distance between the crane hookandthe load coil than thefirsttype. Nonetheless the vertical distance between the crane hook and the load rernains large and, as a result,these grabs cannot lift coils to great heights in buildings where the lift height ofthe crane is limited. In orderto carry out such lifts it may be necessaryto dismount the grab and resort two inconvenient manual slinging of the load. Considerable operational advantages could be realised if a coil grab could be made with a very small vertical distance between the hook ofthe crane and the load coil. According to the present invention there is provided a releasable device for handling loads in conjunction with a crane orsimilarequipmentwhereby the elements of the device are arranged so that a hook of the crane may be situated vertically above and adjacent to the load, comprising a main framework having at or near its center a space adapted to receive the hook of the associated crane thus ensuring that the lower surface ofthe hook is above the top surface of the load by only a small working clearance, the main framework also having a number of holes which co-operate with a connecting pin, permitting the connecting pin to move axially thus enabling a releasable connection forthe hook, a number of sliding bearingsfixed to the mainframework, upon which slide a number of pairs of sliding beams, a numberofstructural membersforming an end frame structure which unites each pairofsliding beams one tothe other, a numberoffinger like projections per- manently attached to the end frame structure, a number of saddles releasably attached to the finger like projections to co-operate with the load, a power and drive system to drive the sliding beams overthe desired range enabling the grabbing or releasing of coils ofvarious sizes, a bridle rotatably attached to the main frame and shaped to fit around a pulley block of the associated crane, in such a way as to permit the transmission oftorque, a power and drive system to rotate the bridle with respect to the main frame, this slewing drive system being required to transmit slewing torque only, the lifting load being carried by a bearing between the hook and the pulley block of the associated crane. A specific embodiment of the invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 shows a side view of the lifter with a load coil and the ropes, block and hook of the associated crane. Figure2 shows an end view of the lifter with a load coil and the ropes, block and hook of the associated crane. Figure 3 shows a plan view of the lifter with the ropes and block of the associated crane. Figure 4shows in perspective the lifter without a load coil, suspended from the ropes, block and hook of the associated crane. Referring to the figures the lifting device comprises a releaseable pin 1 which passes through holes 8 in the centre beams 9 of the main frame 2. The pin 1 maybe moved axially using the handle 10, to permit release from or engagement to the hook H, of the associated crane. Permanently attached to the central beams 9 are upper end beams 11 and lower end beams 12. Permanently attached to the upper end beams 11 and the lower end beams 12 are side beams 13. Permanently attached to the side beams 13 and the centre beams 9 are the upper bearing support beams 14 and the lower bearing support beams 15. Attached to these beams 11,12,14, 15 are replaceable plain bearings 16. Between the upper and lowerbearingsareslidablymounted a numberof sliding beams 4.These sliding beams are joined in pairs by end frame members 5,to which arefixed fingers 6 projecting inwards. Upon this finger is mounted a replaceable saddle 7 which engages with the bore ofthe load L. In order to control the movement of the saddles 7, so that they may engage or disengage with the bore of loads L of different sizes, the sliding beams 4 have fixed to their inner surfaces a toothed rack 19 which engages with a gear20,which is in turn driven by shaft 21. Shaft 21 is driven by the electric motor/ gearbox unit 25 via the bevel gearboxes 22 and shafts 24. The hook H ofthe associated crane is rotatablyfree but axially restrained on the hook swivel bearing Sin the block B which is supported on ropes R. The lifting device is made to slew by causing relative rotation between the block Band the main frame 2, while the vertical load is carried on the hook swivel bearing S. The bridle 33 has cut into itan approximately rectangu lar hole 35 wh ich co-operateswiththeblockB to transmit the torque reaction associated with the slewing motion. Attached to the bridle 33 is an electric motor/gearbox unit 32 which drives a gear 30 which in turn meshes with a large ring gear29. This ring gear is in turn attached to the main frame 2. The bridle is constrained to rotate co-axiallywith the hook swivel bearing and restrained axially by a number of bearings 34. CLAIMS

1. Areleasabledeviceforhandling loads in con junction with a crane or similar equipment whereby the elements of the device are arranged so that the hook of the crane may be situated vertically above and adjacent to the load.

2. A device as described in claim 1 where the working elements ofthe device are disposed wholly or partly within the same vertical space as the block and hook of the associated crane.

3. A device as described in claims and 2 where there are provided pairs of sliding beams, the 2 members of each pair being on the opposite sides of the centre line ofthe device, and so pitched as to create a space around the centre line of the device thus permitting the hook and block of the crane to be mounted adjacentto the load.

4. A device as described in claim 1, where the hookofthecraneisrotatablyfixed in the mainframework, and the block of the crane is rotatably fixed in a bridle, the said bridle and said main framework being capable of controlled relative rotation by a drive system which is required to provide only rotational control, the vertical loads being carried with rotational freedom, by the hook swivel bearing.

5. A releasable device for handling loads in con junction with a crane or similar equipment whereby the elements of the device are arranged so that a hook of the crane may be situated vertically above and adjacent to the load, comprising a mainframe- work having at or near its centre a space adapted to receive the hook of the associated crane thus ensuring thatthe lower surface of the hook is abovethetop surface ofthe load by only a small working clearance, the main framework also having a number of holes which co-operate with a connecting pin, permitting the connecting pin to move axially thus providing a releasable connection for the hook, a number of sliding bearings fixed to the main framework, upon which slide a number of pairs of sliding beams, a number of structural members forming an end frame structure which unites each pair of sliding beams one to the other, a number of finger like projections permanently attached to the end frame structure, a number of saddles releasably attached to the finger like projections to co-operate with the load, a power and drive system to drive the sliding beams overthe desired rangeto permitthe grabbing or releasing of coils of various sizes, a bridle rotatably attached to the main frame and shaped to fit around a pulley block ofthe associated crane in such a way asto permitthe transmission of torque, a power and drive system to rotatethe bridlewith respectto the main frame, this slewing drive system being required to transmit slewing torque only, the lifting load being carried bya bearing between the hookandthe pulley blockofthe associated crane.

6. A releasable device for suspending loads from acraneorsimilarliftingequipmentsubstantiallyas described herein with reference to Figures 1 - 4 ofthe accompanying drawing.