Abstract:
A lifting sling assembly comprises a centering collar element forming a concentric sleeve around a central concavity, a centering housing element, a wire rope, and a lifting support. The centering housing element is defined by a concentric flange member forming a concentric sleeve around the centering housing element. The wire rope is inserted into the central concavity, and the centering collar element is swaged onto the wire rope. The centering collar element, the centering housing element, and the concentric flange member are integrated into a contiguous non-welded assembly such that the wire rope remains rigid within the centering collar member. The lifting support is a mechanical support lifting apparatus.

Description:
BACKGROUND 
     BOPs (Blow out Preventers) and other drilling equipment used on land based wells must be removed and replaced in the process of performing services on the well. These devices are important to the safety of the well and are considered as critical safety assets. Service companies have used various types of lifting assemblies to remove and replace the equipment. Such assemblies are typically attached to an elevator and then connected to the equipment to be lifted. A problem exists in the security and efficiency of these lifting assembly connections between an elevator and the equipment. 
     Conventional lifting assemblies suffer from one or more deficiencies. For example, such assemblies may contain insecure connections to the elevator. Such insecure connections may result in damage to the equipment. The connections may often be easily removable, and may be removed or misplaced. Such lifting assemblies often employ non-standard assembly components, and are not properly tagged or marked. Therefore, a need exists for a contiguous lifting sling assembly which provides a secure and efficient method of lifting. 
     SUMMARY 
     Embodiments of the invention are directed towards solving the need for a lifting sling assembly which provides a secure and efficient method of lifting. Embodiments of the invention comprise a unique proprietary design of a lifting sling assembly which in turn connects to an elevator. The lifting sling assembly provides a secure connection to the elevator and may be implemented to fit differing dimensions of elevators. In an embodiment, the lifting assembly is a permanent, contiguous assembly with a centering housing element, a centering collar element, and a concentric flange member. Wire rope is inserted into a central concavity within the centering housing element, and the centering housing element is swaged onto the cable. A lifting means is attached to the wire rope. This assembly prevents components from being removed and misplaced. The lifting assembly may also be recertified with specification and working load limits. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other features, aspects and advantages of embodiments of the invention will become better understood with regard to the following description, appended claims, and accompanying drawings where: 
         FIG. 1  is a front view of a lifting sling assembly according to an embodiment of the invention; 
         FIG. 2  is a side view of a lifting sling assembly according to the embodiment of  FIG. 1 ; 
         FIG. 3  is a cross-sectional top view of a centering collar element, centering housing element, and concentric flange member, according to the embodiment of  FIG. 1 ; 
         FIG. 4  is a cross-sectional front view of a centering collar element, centering housing element, and concentric flange member, according to the embodiment of  FIG. 1 ; 
         FIG. 5  is a cross-sectional bottom view of a centering collar element, centering housing element, and concentric flange member, according to the embodiment of  FIG. 1 ; 
         FIG. 6  is a cross-sectional front view of a centering collar element, centering housing element, and concentric flange member, and a wire rope, according to the embodiment of  FIG. 1 ; 
         FIG. 7  is a partial cross-sectional front view of a centering collar element, centering housing element, and concentric flange member, and a wire rope, according to the embodiment of  FIG. 1 ; 
         FIG. 8  is a front view of a lifting sling assembly according to a first alternate embodiment of the invention; 
         FIG. 9  is a front view of a lifting sling assembly according to a second alternate embodiment of the invention; 
         FIG. 10  is a side view of a lifting sling assembly according to the embodiment of  FIG. 9 ; 
         FIG. 11  is a cross-sectional top view of a centering collar element, centering housing element, concentric flange member, and lifting eye member, according to the embodiment of  FIG. 9 ; 
         FIG. 12  is a cross-sectional front view of a centering collar element, centering housing element, concentric flange member, and lifting eye member, according to the embodiment of  FIG. 9 ; 
         FIG. 13  is a cross-sectional side view of a centering collar element, centering housing element, concentric flange member, and lifting eye member, according to the embodiment of  FIG. 9 ; 
         FIG. 14  is a cross-sectional bottom view of a centering collar element, centering housing element, concentric flange member, and lifting eye member. according to the embodiment of  FIG. 9 ; 
         FIG. 15  is a side view of a centering collar element, centering housing element, concentric flange member, lifting eye member, and wire rope, according to the embodiment of  FIG. 9 ; 
         FIG. 16  is a front view of a centering collar element, centering housing element, concentric flange member, lifting eye member, and wire rope, according to the embodiment of  FIG. 9 ; 
         FIG. 17  is a partial cross-sectional bottom view of a centering collar element, centering housing element, concentric flange member, lifting eye member, and wire rope, according to the embodiment of  FIG. 9 ; 
         FIG. 18  is a cross-sectional front view of a centering collar element, centering housing element, concentric flange member, lifting eye member, and wire rope, according to the embodiment of  FIG. 9 ; 
         FIG. 19  is a partial cross-sectional front view of a centering collar element, centering housing element, concentric flange member, lifting eye member, and wire rope, according to the embodiment of  FIG. 9 ; 
         FIG. 20  is a front view of a lifting sling assembly according to a third alternate embodiment of the invention; 
         FIG. 21  is a front view of a lifting sling assembly with an attached sliding choker hook according to the embodiment of  FIG. 20 ; 
         FIG. 22  is a front view of a centering collar element, centering housing element, concentric flange member, lifting eye member, and wire rope with an attached sliding choker hook according to the embodiment of  FIG. 20 ; 
         FIG. 23  is a side view of a centering collar element, centering housing element, concentric flange member, lifting eye member, and wire rope with an attached sliding choker hook according to the embodiment of  FIG. 20 ; 
         FIG. 24  is a front view of a lifting sling assembly attached to an elevator according to the embodiment of  FIG. 20 ; 
         FIG. 25  is a front view of a centering collar element, centering housing element, concentric flange member, lifting eye member, and wire rope, attached to an elevator, according to the embodiment of  FIG. 20 ; and 
         FIG. 26  is a side view of a centering collar element, centering housing element, concentric flange member, lifting eye member, and wire rope, attached to an elevator, according to the embodiment of  FIG. 20 . 
     
    
    
     DESCRIPTION 
     Overview 
       FIGS. 1-7  illustrate a lifting sling assembly according to a preferred embodiment of the invention. As shown in  FIGS. 1-7 , a lifting sling assembly  11  has a centering collar element  12 , a wire rope  20 , a centering housing element  30 , and a lifting support means  40 . 
     DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT 
     According to the preferred embodiment, a centering collar element  12  is a longitudinally extending rigid cylindrical member, with a central concavity  13 . The centering collar element  12  is shaped such that if forms a concentric sleeve around the central concavity  13 . The centering collar element outer diameter  12   a  is shown in  FIG. 4 . The centering collar element  12  is constructed such that the central concavity  13  can accommodate a wire one inch (1″) to (2″) in diameter. 
     A wire rope  20  is an elongate wire constructed of resilient tensile material. the wire rope  20  of the preferred embodiment is a type of rope implementing a plurality of strands of metal wire twisted into a helical pattern. The diameter of the wire rope  20  in the preferred embodiment is one inch (1″) to two inches (2″) in diameter (although other embodiments may use varying wire dimensions) of desired length. 
     A centering housing element  30  is a longitudinally extending rigid cylindrical member. A concentric flange member  31  is a concentric sleeve surrounding the centering housing element  30 . As shown in  FIGS. 3-7 , the concentric flange member  31  has a lower flange surface  32 , and side flange surface  33 . The centering housing element outer diameter  30   a  (the diameter below the flanged portion) is approximately the same as the centering collar element outer diameter  12   a , as shown in  FIG. 4 . The flange outer diameter  31   a  is greater than that of the centering housing element outer diameter  30   a  and the centering collar element outer diameter  12   a , as shown in  FIG. 4 . The centering housing element  30 , concentric flange member  31 , and centering collar element  12  are machined as one continuous element. The shape and dimensions of the concentric flange member  31  may be adapted to fit existing tools. For example, in the preferred embodiment, the concentric flange member  31  may be adapted to fit both 2⅜″ and 2⅞″ elevators. 
     A lifting support  40  is a mechanical support lifting apparatus. In the lifting support  40  of the preferred embodiment, the wire rope  20  has a wire rope termination  41 . The wire rope termination  41  is a wire rope thimble eye  42  with a D-Ring  43  fabricated into the wire rope thimble eye  42 , as shown in  FIGS. 1-2 . Two lifting wire rope legs  44   a ,  44   b , of equal length are fabricated into the D-Ring  43  via wire rope leg thimble eyes  44   c ,  44   d . The diameter of the wire rope legs  44   a ,  44   b , may vary according to specific load parameters. The diameter of the wire rope legs  44   a ,  44   b  also determines the final working load limit of the assembly, with larger diameter ropes providing an increased working load limit. Lifting wire rope leg  44   a ,  44   b  diameters may range from ½″ to ⅞″ in the preferred embodiment. A lifting termination  45  forms the connection point for the intended load, as shown in  FIGS. 1-2 . According to the preferred embodiment, the lifting termination  45  implements two lifting eyes  46   a ,  46   b , as shown in  FIGS. 1-2 . The lifting support  40  of the preferred embodiment may include one or more wire rope sleeves  47 , as shown in  FIGS. 1-2 . 
     The wire rope  20  is inserted into the central concavity  13 . The centering collar element  12  is swaged onto the wire rope  20 . The swaging provides a permanent and continuous assembly of the wire rope  20 , into the centering collar element  12 . Accordingly, the wire rope  20 , centering collar element  12 , centering housing element  30 , and concentric flange member  31  exist as one continuous element constructed of steel. 
     During operation, the lifting sling assembly  11  provides a means of lifting point loads such as BOPs and other drilling equipment. In the lifting of a BOP, an elevator mutually engages the outer periphery of the upper portion of the centering collar element  12 . The lower flange surface  32  forms a load bearing surface, contacting the top of the elevator. A BOP or drilling equipment can be connected to the lifting termination  45 . The elevator then may lift or descend the lifting sling assembly  11  and attached load. 
     Advantages of the Invention 
     Embodiments of the lifting sling assembly provide a secure and efficient method of lifting. The assembly of the wire rope  20 , centering collar element  12 , centering housing element  30 , and concentric flange member  31  is a permanent, contiguous assembly. The individual components cannot be removed or misplaced. Such permanent assembly provides a secure and efficient connection of the equipment. Secure connections, contiguous assembly, and use of wire rope instead of abrasive material such as chain, minimizes the potential of damaging equipment in the process of lifting, removing, or replacing such equipment. Moreover, the assembly can be certified and tagged according to specifications and working load limits when fabricated, and may be recertified by the manufacturer periodically to insure integrity and safe use of assembly over time. Such uniform design may allow for a specified safety rating to be applied to such systems. 
     The upper portion of the centering housing element  30 , and concentric flange member  31  are designed to fit existing hardware. For example, systems implementing the proprietary design may fit both 2⅜″ and 2⅞″ elevators. The lifting support means can be adapted to fit differing working load parameters, while still maintaining a uniform connection to the elevator. The uniform assembly allows inspection and recertification at periodic intervals, such as on an annual or more frequent basis. The recertification process is more efficient as no welds are used in the assembly. The connection has a higher efficiency rating, due to the integration of the individual elements. The entire assembly is designed to be a lightweight movable piece, such that can be easily operated and moved by one and two man crews. 
     Alternatives 
     Although the invention has been set forth in the previously described best mode, other alternative embodiments are possible. For example, the types of lifting terminations may vary according to desired load characteristics. The lifting terminations may include thimble eye/shackles, standard eyes, oversize eyes, or sliding choker hooks. 
       FIG. 8  shows a first alternate embodiment of the invention. According the embodiment, a lifting sling assembly  111 , has a centering collar element  112 , a wire rope  120 , a centering housing element  130 , a concentric flange member  131 , and a lifting support  140 . The lifting support means has a wire rope termination  141 , a wire rope thimble eye  142 , a D-Ring, two lifting wire rope legs  144   a ,  144   b , wire rope leg thimble eyes  144   c ,  144   d , a lifting termination  145 , two lifting eyes  146   a ,  146   b , one or more wire rope sleeves  147 , and one or more sliding choker hooks  148 , as shown in  FIG. 8 . 
       FIGS. 9-19  illustrate a second alternate embodiment of the invention. According the embodiment, a lifting sling assembly  211 , has a centering collar element  212  with a central concavity  213 , a wire rope  220 , a centering housing element  230 , a concentric flange member  231 , a lifting support  240 , and a lifting eye member  250 . The lifting support means has a wire rope termination  241 , a wire rope thimble eye  242 , a D-Ring, two lifting wire rope legs  244   a ,  244   b , wire rope leg thimble eyes  244   c ,  244   d , a lifting termination  245 , two lifting eyes  246   a ,  246   b , and one or more wire rope sleeves  247 , as shown in  FIGS. 9-19 . The two lifting wire rope legs  244   a ,  244   b , are fabricated into a D-Ring  243 , via the wire rope thimble eyes  244   c ,  244   d . The centering housing element  230 , concentric flange member  231 , lifting support  240 , and lifting eye member  250  are machined as one solid contiguous piece without the use of welding. The wire rope  220  is inserted into the centering collar element  212 , and the centering collar element  212  is swaged onto the wire rope  220 . 
     The wire rope  220  is inserted into the central concavity  213 . The centering collar element  212  is swaged onto the wire rope  220 . The swaging provides a permanent and continuous assembly of the wire rope  220 , into the centering collar element  212 . Accordingly, the wire rope  220 , centering collar element  212 , centering housing element  230 , and concentric flange member  231  exist as one continuous element constructed of steel. 
       FIGS. 20-26  illustrate a third alternate embodiment of the invention. According the embodiment, a lifting sling assembly  311 , has a centering collar element  312 , a wire rope  320 , a centering housing element  330 , a concentric flange member  331 , a lifting support  340 , and a lifting eye member  350 . The lifting support means has a wire rope termination  341 , a wire rope thimble eye  342 , a D-Ring, two lifting wire rope legs  344   a ,  344   b , wire rope leg thimble eyes  344   c ,  344   d , a lifting termination  350 , two lifting eyes  346   a ,  346   b , and one or more wire rope sleeves  347 , and one or more sliding choker hooks  348 , as shown in  FIGS. 20-26 . The centering housing element  230 , concentric flange member  231 , lifting support  240 , and lifting eye member  250  are machined as one solid contiguous piece without the use of welding. The wire rope  220  is inserted into the centering collar element  212 , and the centering collar element  212  is swaged onto the wire rope  220 .  FIGS. 21-23  shown the lifting sling assembly  311  attached to a safety bolt shackle  390 .  FIGS. 24-27  show the lifting sling assembly  311  connected to an elevator  360 . 
     Differing combinations and permutations of the embodiments set forth are contemplated by the current invention. Additionally, all functional equivalents of materials used and means of attachment of elements are contemplated by the current invention. Therefore, the spirit and scope of the appended claims should not be limited to the descriptions of the preferred versions and alternate embodiments set forth herein. Any element in a claim that does not explicitly state “means for” performing a specified function, or “step for” performing a specific function, is not to be interpreted as a “means” or “step” clause as specified in 35 U.S.C. §112, ¶6. In particular, the use of “step of” in the claims herein is not intended to invoke the provisions of 35 U.S.C. §112, ¶6.