Abstract:
An encapsulated sling including a sling formed in one piece or in multiple pieces or sections joined end to end by a pin at a juncture between adjacent ends, the sling having a spaced apart pair of eyes adjacent its opposed ends to permit the sling to be suspended from a hoist or other structure and possibly one or more intermediate eyes between its ends to permit the suspended length of the sling to be reduced, the sling being surrounded by a sleeve fabricated from a flexible, polymeric material, such as PVC or a PVC coated material, which covers the entire length of the sling between its eyes, including the edges of the slings. The sleeve further comprises pockets positioned to cover the top and bottom surfaces of the eyes. In a multiple piece sling, the protective sleeve is formed in end to end sections, each of which covers one of the sections of the sling to permit the joined sling sections to be unjoined, and the encapsulated sling is further provided with a slidable sleeve which surrounds the protective sleeve and which is slidable therealong to cover the juncture between adjacent sling sections and adjacent protective sleeve sections during the use of said sling.

Description:
BACKGROUND OF THE INVENTION 
     1. Field Of The Invention 
     This invention relates to a sling for use in hoisting boats or other heavy objects. More particularly, this invention relates to a sling of the foregoing character which is encapsulated with suitable protective elements to prevent the sling from being damaged by ultraviolet light and/or by dirt and gravel and other abrasive substances that the sling can contact during its normal use, and to prevent or substantially prevent the sling from damaging the surfaces of the objects it is used to hoist. 
     2. Description Of The Prior Art 
     My prior U.S. Pat. No. 5,037,237, the disclosure of which is hereby incorporated by reference, describes the use of slings in hoisting a boat, and discusses the problems of contact damage that can be caused to a boat during hoisting by dirt or gravel or other debris that can be picked up by a sling, especially a sling of a coarse texture. The aforesaid U.S. Pat. No. 5,037,237 solves such problems by teaching the use of separate protectors releasably affixed to the lifelines or other elements of the boat and positioned between the hull of the boat and each of the slings used to hoist the boat to thereby prevent such contact damage. However, many marinas are reluctant to use protectors of the type taught in the aforesaid U.S. Pat. No. 5,037,237, because the affixing of the protectors to the boat prior to the hoisting operation, and the removal of the protectors after the hoisting operation, slows down the hoisting operation and therefore at least somewhat increases the initial expense to the marina in conducting its hoisting operations. 
     While the use of protectors according to the aforesaid U.S. Pat. No. 5,037,237 is quite effective in preventing contact damage to a boat or other hoisted object from debris carried by a sling, it does not protect the sling from abrasion or other contact damage caused by the initial and subsequent relative motion and other contact between the sling and such debris, which can materially shorten the useful life of a sling relative to that of a comparable sling which is not suitably protected from such contact. Further, many slings are woven from polyester or polyamide (Nylon) or other ultraviolet light sensitive materials, and ultraviolet light degradation of such slings can also materially shorten the life of such slings, especially those used in Southern states of the United States and in other locations having similar climatic conditions. U.S. Pat. No. 3,622,025 (Peterson) teaches the use of pads to protect a boat sling from damage by contact with fittings on the hulls of hoisted boats. However, the protective pads of this reference are too short and too narrow to protect the eyes and the edges of a sling from the kinds of damage that can occur when a sling is dragged across rough terrain and do not protect enough of the length of the sling to effectively retard ultraviolet light degradation of slings made from light sensitive materials. 
     SUMMARY OF THE INVENTION 
     According to the present invention there is provided a sling which is encapsulated by one or more suitable flexible protective elements, preferably throughout the entire length of the sling including its eyes at its opposed ends and any extra, intermediate eyes. The protective elements of the sling of the present invention protect the encapsulated sling, including its eyes and edges, from contact damage with the ground and the objects to be hoisted by the sling, and further protect the sling from damaging exposure to ultraviolet light. Such protective elements, which are preferably fabricated from a flexible polymeric material with a smooth, product engaging surface, such as polyvinyl chloride (PVC) or a PVC coated fabric or other material, can be readily removed and reattached to permit frequent inspection of the encapsulated sling to ensure that it is still suitable for use, as is required by many health and safety codes and regulations. Further, the smoothness of the product engaging surface of the protective elements of the slings helps to prevent debris from accumulating on such surface, and further simplifies the removal of any accumulated debris by shaking or rinsing or the like, and thereby helps to prevent or minimize contact damage to the boat or other hoisted object. 
     Accordingly, it is an object of the present invention to provide an improved sling for use in hoisting boats or other heavy objects. More particularly, it is an object of the present invention to provide a sling of the foregoing character which is more resistent to life shortening contact with external debris and other objects and/or which is more resistent to life shortening exposure to ultraviolet radiation. It is also an object of the present invention to provide a sling of the foregoing character which is less likely to cause contact damage to the external surfaces of the objects that are hoisted by such sling. 
     For a further understanding of the present invention and the objects thereof, attention is directed to the drawings and the following brief descriptions thereof, to the detailed description of the preferred embodiment, and to the appended claims. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     FIG. 1 is a perspective view of an encapsulated sling according to a preferred embodiment of the present invention; 
     FIG. 2 is a fragmentary perspective view, at a somewhat enlarged scale, of a portion of the encapsulated sling of FIG. 1; 
     FIGS. 3 and 4 are views similar to FIG. 2 of an alternative embodiment of an encapsulated sling according to the present invention in different stages of the assembly of such sling; 
     FIG. 5 is a partly exploded view similar to FIG. 2 of an alternative embodiment of an encapsulated sling according to the present invention; and 
     FIG. 6 is a fragmentary view of the encapsulated sling of FIG. 5 illustrating a step in the assembly of such encapsulated sling. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     An encapsulated sling according to the preferred embodiment of the present invention is indicated generally by reference numeral 10 in FIGS. 1 and 2. The encapsulated sling 10 is made up of an otherwise conventional woven fabric or polyester load bearing sling 12 surrounded or encapsulated by a protective sleeve 14, preferably of a non-load bearing character. As illustrated, the sling 12 is manufactured in one piece and is provided with an opposed pair of open ends or eyes 12a, 12b by which the sling 10 may be suspended from attachments of a traveling hoist, not shown, or from any other suitable structure. As is known, prior art slings are usually used in pairs with a spacing between the slings in each pair for proper positional stability of the load during hoisting, and it is recommended that encapsulated slings 10 be used in such a manner. In any case, the sling 12 may also be provided with one or more additional eyes between its opposed ends 12a, 12b, such as the eye 12c, by which the length of the sling 10 that is suspended between the attachments of a hoist can be shortened. 
     The protective sleeve 14 is fabricated from a flexible material with at least an inner, product contacting surface 14d which is quite smooth and resistent to the accumulation of dirt, gravel or other abrasive debris thereon and/or which is more resistant to attack by grease or other chemicals than the material of the sling 12. The flexible material of the protective sleeve 14 is somewhat wider than the width of the sling 12, and the sling 12 is positioned generally centrally between the edges of the sleeve 14, which are then joined to the underlying edges of a like or doubled back portion of the flexible material along the edges 14e, 14f at locations external to the edges of the sling 12. When the sleeve 14 is formed from a single, doubled back length of flexible material, its opposed ends are preferably joined to one another in an overlapped seam. When the sleeve 14 is formed from two or more plys or lengths of flexible material, the lengths are preferably joined in an end to end manner with a lapped seam between adjacent ends of adjacent lengths. In any case, while the joining along the edges 14e, 14f is preferably relatively permanent to minimize the cost of the encapsulated sling 10, it is also contemplated that seams along the edges 14e, 14f can be formed with Velcro hook and loop elements or other readily openable and reclosable joining material, for example, to permit rapid and repeated inspection of the sling 12 to ensure that it is still fit for service. In any case, the protective sleeve 14 is provided with pockets 14a, 14b, 14c which surround the eyes 12a, 12b, 12c, respectively, of the sling 12, and serve to prevent substantial relative longitudinal movement without requiring excessively close clearance therebetween. 
     The protective sleeve 14, thus, protects all portions of the sling 12, including the eyes 12a, 12b, 12c and the opposed edges of the sling between the pockets 12b, 12c and 12c, 12a, from abrasion or other contact damage. Such contact damage can be quite limiting of the useful life of the sling 12 and can occur, for example, when an unprotected sling 12 or at least an end portion thereof is dragged across the ground, paved or unpaved, in a marina or other commercial or industrial job site where slings are frequently used. Such an action can be especially damaging to the eyes of an unprotected sling due to their protruding character and to the edges of an unprotected sling. Further, many slings are formed by weaving polyester or polyamide (Nylon) or other materials which are subject to degradation when exposed to ultraviolet light. Such ultraviolet light degradation can be particularly limiting to the useful life of slings used in Southern states of the United States or in other locations with similar climatic conditions, and is effectively retarded by the use of a protective sleeve 14. Further yet, the inclusion of the eyes 12a, 12b, 12c within the sleeve 14 precludes any substantial relative movement between the sling 12 and the sleeve 14 and thereby ensures that no portion of the hoisted object will be in direct, load bearing contact with any portion of the sling 12. 
     The protective sleeve 14 is preferably formed by fabrication from a flexible, polymeric material with a smooth, product engaging surface 14d to resist the accumulation of abrasive debris thereon, and to facilitate the removal of debris therefrom by rinsing, shaking or the like, to thereby prevent or minimize contact damage to a boat or other heavy object when hoisted by the sling 10. Polyvinyl chloride (PVC) in sheet form or as a coating on or lamination to fabric or on an expanded PVC or polyethylene sheet is well suited in its flexibility, surface smoothness, resistance to surface abrasion damage and ultraviolet light degradation, and cost for such usage, and the overlapping edges of adjacent sheets or layers of a sheet can be readily joined to one another by stitching. Further, such fabrics have sufficient flexibility to facilitate the relatively rapid assembly and disassembly of the sling 12 and the sleeve 14, at least in widths of the sling 12 up to approximately 8 inches, by folding over a pocket at one end of the sleeve 14, for example, the pocket 14a, to permit the end 12b of the sling 12 to be inserted into the opening adjacent the pocket 14a and the sling 12 threaded through the sleeve 14 until the end 12b is received in its pocket 14b. Thus, the sling 12 and the protective sleeve 14 may be readily disengaged to permit a visual inspection of the sling 12 to ensure that it is still fit for its intended usage, as is required by many health and safety codes. When the PVC sheeting is used in conjunction with an expanded or foamed backing material, such as expanded PVC or polyethylene, the backing material will provide a cushioning effect which will help to protect the surface of the hoisted object from contact damage by irregularities on the encapsulated sling 10 and will help to protect the sling 12 from such damage by irregularities on the hoisted object. 
     FIGS. 3 and 4 illustrate an alternative embodiment of an encapsulated sling according to the present invention in which elements that correspond to elements of the embodiment of FIGS. 1 and 2 are identified by 100 series reference numerals, the last two digits of which are the same as the two digits of the corresponding elements of the embodiment of FIGS. 1 and 2, if any. The embodiment of FIGS. 3 and 4 is designed for situations where it is not possible to fold over a pocket of the protective sleeve to insert a sling into the protective sleeve, as described above, for example, in the case of wide slings, such as slings with the width greater than approximately 8 inches, or in the case of a protective sleeve which is fabricated from a relatively bulky material. Thus, FIGS. 3 and 4 illustrate an encapsulated sling which is generally identified by reference numeral 110 and which is made up of a load bearing sling 112 and a protective sleeve 114, preferably of a non-load bearing character, which surrounds or encapsulates the sling 112. 
     The end portion of the sling 112 that is illustrated in FIGS. 3 and 4 has an eye 112a at the outer end thereof, and may also be provided with one or more inner eyes, such as the eye 112c, it being understood that the opposite end portion of the sling 112 that is not illustrated will also be provided with at least one eye. Pockets 114a, 114c are provided in the protective sleeve 114 for receiving the eyes 112a, 112c, respectively, and are formed by releasably joining overlapping portions of the material which is used in the fabrication of the sleeve 114. Velcro hook and eye strips 114g, 114h are applied to the edges of the sleeve 114 in the region of the pocket 114a to facilitate rapid opening and reclosing of the pocket 114a. Similarly, Velcro hook and loop strips 114i, 114j are applied to the edges of the sleeve 114 in the region of the pocket 114c to facilitate rapid opening and closing of the pocket 114c. It is to be noted that the pockets 114a, 114c open in the direction faced by the product contacting surface 114d of the protective sleeve 114 so that the pockets 114a, 114c will have maximum resistance to inadvertent opening during the hoisting of an object. In any case, the protective sleeve 114 is fabricated from a flexible, polymeric material with a smooth, product engaging surface 114d from a suitable flexible, polymeric material, such as any of the materials described above in relation to the fabrication of the protective sleeve 14. 
     FIGS. 5 and 6 illustrate an alternative embodiment of an encapsulated sling according to the present invention in which the elements that correspond to elements of the embodiment of FIGS. 1 and 2 are identified by 200 series reference numerals, the last two digits of which are the same as the two digits of the embodiment of FIGS. 1 and 2, if any. The embodiment of FIGS. 5 and 6 is designed for application to multiple piece slings where a single sling is formed by releasably joining two or more sections of a sling in end to end fashion. Slings of this general type are known in the art, as is disclosed, for example, in the aforesaid U.S. Pat. No. 3,622,025. 
     Thus, FIGS. 5 and 6 illustrate an encapsulated sling which is generally identified by reference numeral 210 and which is made up of a load bearing sling 212 and a protective sleeve 214 that surrounds or encapsulates the sling 212. The sling 212 is made up of individual sling sections 212-1, 212-2 which are disengagably joined to one another by a pin 216 that extends through interleaved loops 212-2a, 212-2b of the section 212-2, and 212-1a, 212-1b, 212-1c of the section 212-1. The pin 216 is releasably retained within the loops of the sling sections 212-1, 212-2 by a cotter pin 218 that extends through an opening 216a in the pin 216 near an end thereof. The pin 216 also has a locking loop 220 tethered to an end thereof, which is opposed to the end carrying the opening 216a. The free end of the loop 220 is interlocked with the cotter pin 218 to help secure the pin 216 and the interleaved loops of the sections 212-1, 212-2 through which it is passed. 
     Because of the multi-piece character of the sling 212, the protective sleeve 214 is fabricated in multiple sections corresponding to the sections in the sling 212, namely protective sleeve sections 214-1, 214-2 in the case of a sling that is made up of sling sections 212-1, 212-2. The sleeve sections 214-1, 214-2 are fabricated from a suitable flexible material, such as any of the flexible materials described above in relation to the sleeve 14 as described above or by a similar fabrication method. 
     For accessibility to the pin 216 to couple or uncouple the sling sections 212-1, 212-2, the plys of the flexible material used in the fabrication of the sleeve sections 214-1, 214-2 have free ends 214-1k, 214-2k on opposed sides of the sling sections 212-1, 212-2. Thus, as is shown in FIG. 5, after the sling sections 212-1, 212-2 are joined by the pin 216, the free ends 214-1k, 214-2k are folded down to closely overlie the sling sections 212-1, 212-2, but may readily be folded back to permit coupling or uncoupling of the sling sections 212-1, 212-2, as is shown in FIG. 6. The sling 210 is further provided with a relatively short sleeve 222 which slidably surrounds the sleeve 214. The sleeve 222, which is also formed from a pair of layers of suitable flexible material by stitching the opposed edges of the layers to one another, is movable to surround the free ends 214-1k, 214-2k of the sleeve sections 214-1, 214-2 to hold them in place during the normal use of the encapsulated sling 210, and to protect the portions of the sling 212-1, 212-2 that would otherwise be exposed to contact and ultraviolet light damage. However, the sleeve is also movable away from such free ends to permit ready access to the pin 216. Because the extra thickness of the sling 212 in the region of the joint between the adjacent ends of the sections 212-1, 212-2, the sleeve 222 can and should be sized to fit rather snugly in this region to be resistant to inadvertent movement during the use of the sling 210 and will still have sufficient clearance with respect to other portions of the sleeve sections 214-1, 214-2 to be freely movable with respect thereto. 
     Although the best mode contemplated by the inventor(s) for carrying out the present invention as of the filing date hereof has been shown and described herein, it will be apparent to those skilled in the art that suitable modifications, variations, and equivalents may be made without departing from the scope of the invention, such scope being limited solely by the terms of the following claims.