Field

[0001] The present invention generally relates to lifting systems used in industry, and in particular to a quick lock and unlock lifting system. While the present invention will be described in relation to off shore oil rig lifting applications, it is to be appreciated that the invention is not limited to this application, and that other applications are also envisaged.

Background

[0002] The following discussion of the background to the invention is intended to facilitate an understanding of the present invention only. It should be appreciated that the discussion is not an acknowledgement or admission that any of the material referred to was published, known or part of the common general knowledge of the person skilled in the art in any jurisdiction as at the priority date of the invention.

[0003] In offshore oil rigs, it is common practice to use a lifting rig on a crane that uses a pair of lift hooks separated by a spreader bar. The use of such a lifting rig requires a large number of personnel to be present to allow for a safe lifting operation to be conducted. This is because personnel must manually engage each hook to the article to be lifted, and to subsequently manually release the hooks from the article after the lift.

[0004] The lifting operation also requires the hooks to be dropped by the crane to a level below the engagement height of the hooks to the article so that the hooks can be manually engaged to the article. This process must then be reversed at the end of the lifting operation, after the crane drops the hooks below the engagement height to allow for manual releasing of the hooks.

[0005] Furthermore, conventional lifting rigs have a limited load capacity requiring a long cycle of pre-lift analysis before any lift can be conducted to ensure that it is possible for the lifting rig to support the load applied by the article during the lifting operation. This, together with the need to manually engage and release the hooks from the article, can lead to la relatively long period of time to organize and accomplish a lift. [0006] Balltec Ltd has developed a lifting apparatus sold under the trademark, LiftLOK™, that uses a ball and taper gripping mechanism to address at least some of the current limitations of existing lifting rigs. Details of the LiftLOK™ apparatus can be found at: https://www.balltec.com/solutions/balltec-liftina-solutions- tools/4-liftlok. This apparatus requires the use of high precision, hardened ball bearings that jam against the surface of an inner passage provided within the article prior to lifting. This apparatus is however an expensive option to manufacture and use.

[0007] An object of the invention is to ameliorate one or more of the above- mentioned difficulties.

Summary

[0008] According to one aspect of the present disclosure, there is provided a lift assembly for lifting an article, the lift assembly being locatable within a passage associated with the article, the passage having a shoulder located therein; the lift assembly including: an elongate main body having a longitudinal axis and including an outer wall; one or more wedge members located adjacent the outer wall; the wedge member(s) being displaceable between a first unlocked position at least substantially adjacent the outer wall and a second locking position having an angular displacement relative to the longitudinal axis of the main body; wherein the main body is passable through the passage when the wedge member(s) is in the first unlocked position, and wherein the wedge member(s) is positioned between the shoulder and the main body when in the second locked position to thereby lock the lift assembly within the passage.

[0009] In some embodiments, the lift assembly may include a plurality of wedge members spaced about the main body.

[0010] In some embodiments, the lift assembly may further include resilient means for retaining the one or more wedge members in the first position. [0011] In some embodiments, the main body may further include a recess in the outer wall for accommodating the wedge member(s) therein when in the first position thereof, the recess further including a peripheral wall for supporting the wedge member when in the second position thereof.

[0012] In some embodiments, the main body may be generally cylindrical in shape and the recess extends about the periphery of the main body.

[0013] In some embodiments, the or each said wedge member may include opposing ends thereof, one end hingedly supported on the peripheral wall of the recess, the opposing end including an engagement surface for engaging the shoulder of the passage.

[0014] In some embodiments, said one end of the or each wedge member may be provided with a curved outer profile, and the peripheral wall of the recess is provided with a radius for accommodating the curved profile thereof.

[0015] In some embodiments, said opposing end of the or each wedge member may be provided with a curved outer profile, and the shoulder of the passage is provided with a radius for accommodating the curved profile thereof.

[0016] In some embodiments, the lift assembly may further include a moveable abutment member for engaging and displacing the wedge member(s).

[0017] In some embodiments, the abutment member may include an actuation ring surrounding the main body for respectively abutting and urging the wedge member(s) between the first and second positions thereof.

[0018] In some embodiments, the actuation ring may include an frustoconical surface for facilitating insertion of the actuation ring between the main body and the wedge members.

[0019] In some embodiments, the lift assembly may further include at least one actuation arm extending from the actuation ring, and a passage extending through the main body for slidably accommodating the actuation arm.

[0020] In some embodiments, the lift assembly may further include actuation means interconnected with the actuation arm(s) for displacing the actuation ring.

[0021] In accordance to another aspect of the present disclosure, there is provided a receptacle housing securable on an article to be lifted, the receptacle including an opening, a passage extending from the opening, and a shoulder within the passage, wherein the passage is adapted to accommodate and be in locking engagement with a lift apparatus as described above.

[0022] In some embodiments, the passage may be generally circular in cross- section, and the shoulder may be an annular step provided within the passage.

[0023] In some embodiments, at least a portion of the passage may be dimensioned to provide a close fit for the lift assembly when inserted therein.

[0024] In some embodiments, the lift assembly may be locked in position within the passage when the wedge members are located in the second locking position.

[0025] According to a further aspect of the present disclosure, there is provided a lifting system including: a receptacle housing securable on an article to be lifted and having an opening, a passage extending from the opening, and a shoulder located within the passage; and a lift assembly including: an elongate main body having a longitudinal axis and including an outer wall; one or more wedge members located adjacent the outer wall; and the wedge member(s) being displaceable between a first unlocked position at least substantially adjacent the outer wall and a second locking position having an angular displacement relative to the longitudinal axis of the main body; wherein the main body is passable through the passage when the wedge member(s) is in the first unlocked position, and wherein the wedge member(s) is positioned between the shoulder and the main body when in the second locking position to thereby lock the lift assembly within the passage. [0026] In some embodiments, the lifting system may further include a plurality of wedge members spaced about the main body.

[0027] In some embodiments, the lifting system may further include resilient means for retaining the one or more wedge members in the first position.

[0028] In some embodiments, the main body may further include a recess in the outer wall for accommodating the wedge member(s) therein when in the first position thereof, the recess further including a peripheral wall for supporting the wedge member when in the second position thereof.

[0029] In some embodiments, the main body may be generally cylindrical in shape and the recess extends about the periphery of the main body.

[0030] In some embodiments, the or each said wedge member may include opposing ends thereof, one end hingedly supported on the peripheral wall of the recess, the opposing end including an engagement surface for engaging the shoulder of the passage.

[0031] In some embodiments, said one end of the or each wedge member may be provided with a curved outer profile, and the peripheral wall of the recess may be provided with a radius for accommodating the curved profile thereof.

[0032] In some embodiments, said opposing end of the or each wedge member may be provided with a curved outer profile, and the shoulder of the passage may be provided with a radius for accommodating the curved profile thereof.

[0033] In some embodiments, the lifting system may further include a moveable abutment member for engaging and displacing the wedge member(s).

[0034] In some embodiments, the abutment member may include an actuation ring surrounding the main body for respectively abutting and urging the wedge member(s) between the first and second positions thereof.

[0035] In some embodiments, the actuation ring may include an frustoconical surface for facilitating insertion of the actuation ring between the main body and the wedge members. [0036] In some embodiments, the lifting system may further include at least one actuation arm extending from the actuation ring, and a passage extending through the main body for slidably accommodating the actuation arm.

[0037] In some embodiments, the lifting system may further include actuation means interconnected with the actuation arm(s) for displacing the actuation ring.

[0038] Other aspects and features of the present invention will become apparent to those of ordinary skill in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures.

Brief Description of the Drawings

[0039] In the figures, which illustrate, by way of example only, an embodiment of the present invention, wherein

Figure 1 is a side partially phantom view of a lifting system including a lifting assembly and receptacle housing according to an embodiment of the present invention, with the lift assembly shown in a locked position within the receptacle housing;

Figure 2 is a cross-sectional view of the lifting system of Figure 1 taken along line A- A of Figure 1 ;

Figure 3 is a side partially phantom view of the receptacle housing of the lifting system of Figure 1 ;

Figure 4 is a cross-sectional view of the receptacle housing of Figure 3 taken along line B-B of Figure 3;

Figure 5 is a side partially phantom view of the main body of the lift assembly of the lifting system of Figure 1 ;

Figure 6 is a cross-sectional view of the main body of the lift assembly of the lifting system of Figure 1 taken along line C-C of Figure 5;

Figure 7 is a side view of an abutment member of the lift assembly of the lifting system of Figure 1 ; Figure 8 is a cross-sectional view of the abutment member of the lift assembly of the lifting system of Figure 1 taken along line D-D of Figure 7;

Figure 9 is a side view of the wedge members of the lift assembly of Figure 1 ; and

Figure 10 is a perspective view of the wedge member of Figure 9.

Detailed Description

[0040] Throughout this document, unless otherwise indicated to the contrary, the terms “comprising”, “consisting of”, “having” and the like, are to be construed as non- exhaustive, or in other words, as meaning “including, but not limited to”.

[0041] Furthermore, throughout the specification, unless the context requires otherwise, the word “include” or variations such as “includes” or “including” will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.

[0042] Terms such as ‘upper’, and ‘lower’ are used in the specification to refer to the typical in use orientation of the described embodiment. It is however to be understood that these terms are not intended to limit the scope of the present invention, and that alternative orientations are also envisaged.

[0043] Referring initially to Figs. 1 and 2, there is shown a lifting system 1 for lifting an article and according to an embodiment of the present invention. The lifting system 1 includes a lift assembly 2, which is mounted at the end of a crane cable when in use. The lifting system 2 further includes a receptacle housing 3 which is secured to the article to be lifted. The receptacle housing 3 includes a passage 11 extending from an opening 10 provided within the upper end of the housing 3. The passage 11 extends longitudinally through the receptacle housing 3 and includes an annular shoulder 15, the purpose of which would be subsequently described.

[0044] The lift assembly 2 includes an elongate main body 5 having a longitudinal axis 4 extending longitudinally therethrough as shown in Figure 2. The main body 5 has an outer substantially cylindrical wall 6, with a recess 8 being provided within the outer wall 6, the recess 8 extending substantially radially about the periphery of the main body 5. The lifting assembly 2 supports one or more wedge members 7 with eight such wedge members 7 being provided in the present embodiment spaced around the main body 5. Each wedge member 7 is initially located within the recess 8 in a first “unlocked” position prior to use (not shown). The wedge members 7 are located at least substantially adjacent to the outer wall 6 within the recess 8 when in the first “unlocked “position. This allows the lift assembly 2 freely move into and through the passage 11 of the receptacle housing 3. The lift assembly 2 further includes an abutment member 9 for urging the wedge members 7 to a second “locked” position as shown in Figs. 1 and 2. In the second “locked” position, the wedge members 7 have an angular displacement relative to the longitudinal axis 4 of the main body 5. This locks the lift assembly 2 within the passage 11 , with the wedge members 7 being positioned between the passage annular shoulder 15, and a lower peripheral wall 21 of the recess 8. The wedge members 7 are then jammed between the annular shoulder 15 and lower peripheral wall 21 when a force is applied to the lift assembly 1 in a direction that would otherwise lead to extraction of the lift assembly 2 from the receptacle housing 2 if the wedge members 7 were in the first “unlocked” position.

[0045] Figs. 3 and 4 respectively show more details of the receptacle housing 3 that can be secured, for example by welding, to the article to be lifted. The passage 11 is generally cylindrical in shape, and has an enlarged cavity 16 located in an intermediate position within the passage 14. The cavity 16 is defined at an upper end by the previously described annular shoulder 15, and at the opposing lower end with a frustoconical portion 17 connecting the cavity 16 to the lower end of the passage 11. The receptacle housing 3 is shown in its in use orientation in Figs. 3 and 4 with an opening 10 provided an upper end thereof, the annular shoulder 15 being located at the upper part of the cavity 15, and the frustoconical portion 17 being located at the lower part thereof. It is to be appreciated that the passage 11 may alternatively be provided within the article to be lifted itself, instead of being within a separate receptacle housing 3.

[0046] Figs. 5 and 6 respectively show the main body 5 of the lift assembly 2. Also shown is a generally circular retaining member 23 located adjacent the lower peripheral wall 21 of the recess 8 that passes through apertures 35 provided at or adjacent a lower end 32 of wedge members 7 to thereby hold the lower end 32 of wedge members 7 in place adjacent the lower peripheral wall 21 , and to allow for the wedge members 3 to be hingedly supported thereon. Further apertures 37 may be provided at or adjacent the opposing upper end of the wedge members 7. A resilient means (not shown) such as a spring or a resilient band may be passed through the upper apertures 37 to hold the wedge members 7 in the first unlocked position within the recess 8 until such times the abutment member 9 urges the wedge members 7 in an angular displacement to the second locked position.

[0047] Referring now to Figs. 7 and 8, there is shown the abutment member 9 having an actuation ring 25 with an outer frustoconical surface 27 for engaging an inner face 39 of the wedge members 7. A pair of elongate actuation arms 29 extend from the actuation ring 25. The main body 5 further includes a pair of longitudinal passages 12 extending from the top of the main body 5 through to the recess 8 and extending parallel to the longitudinal axis 4 of the main body 5. These longitudinal passages 12 slidably accommodate the actuation arms 29 of the abutment member 9. Actuation means such as a hydraulic or pneumatic ram (not shown) is interconnected to the actuation arms 29 to thereby displace the actuation ring 25 downwards when the wedge members 7 need to be urged to the second locking position, and upwards to allow the wedge members 7 to return to the first unlocked position.

[0048] The main body 5 further includes a frustoconical shape lower end 24 which acts to facilitate the travel of the lift assembly 2 into the passage 11 . The frustoconical surface 17 within the passage 11 also assist in guiding the lift assembly 2 through into the lower portion of passage 11 . The clearance between the main body 5 of the lift assembly 2 and the upper and lower portions of the passage 11 may be close to ensure there is minimal play between the lift assembly 2 and the receptacle housing 3 when in the locked position.

[0049] Referring to Figs. 9 and 10, each wedge member 7 has an upper and lower end 31 , 33, with each end having a curved profile. The lower peripheral wall 21 of the recess 8 has a radius for accommodating the curved profile of the wedge member lower end 31 to thereby support the wedge members 7 when being angularly displaced. The passage annular shoulder 15 similarly has a radius for engaging the wedge member upper ends 33 ensuring that the wedge members 7 are securely held against the annular shoulder 15 when in the second locked position.

[0050] The lift system 1 works in the following way. The lift assembly 2, which is located at the end of a crane cable, is lowered through the opening 10 of the receptacle housing 3 which has been previously secured by welding to the article to be lifted. The lift assembly 2 continues to be lowered to the receptacle housing 2 until the wedge members 7 are positioned below the annular shoulder 15 of the passage 11 . The abutment member 9 is now lowered to angularly displace the wedge members 7. The lift assembly 2 is then lifted slightly so that the upper ends 33 of each wedge member 7 engage the annular shoulder 15 of the passage 11. The lift assembly 2 is then locked within the receptacle housing 3 thereby allowing the lift of the article. At the end of the lift, the operational sequence is reversed with the lift assembly 2 being lowered and the actuation member 9 raised thereby releasing the wedge members 7 from engagement with the annular shoulder 15. The wedge members 7 then return to the first unlocked position within the recess 8 to thereby allow for the lifting assembly 2 to be extracted from the passage 11 .

[0051] The present invention provides a quick lock and unlock lifting system that can reduce the time required to plan a lift, and reduce the number of personnel required for that lift. The lifting system will also have a higher load capacity than conventional hooks. It is estimated that the load capacity will be around 5000 metric tonnes. This reduces or eliminates the need for pre-lift analysis prior to a heavy lift. Furthermore, as the wedge members 7 will be under a compressive load during lifting, it is not necessary to use a high strength material to manufacture the wedge members 7 leading to lower manufacturing cost. Furthermore, the shape of the receptacle housing 3 and main body 5 is inherently strong and can therefore be made from normal strength material.

[0052] It should be appreciated by the person skilled in the art that the above invention is not limited to the embodiments described. In particular, modifications and improvements may be made without departing from the scope of the present invention. Alternative means other than the above described abutment member 9 could for example be used to displace the wedge members 7 between the first unlocked and second locked positions. [0053] It should be further appreciated by the person skilled in the art that one or more of the above modifications or improvements, not being mutually exclusive, may be further combined to form yet further embodiments of the present invention.