Patent Publication Number: US-2004040123-A1

Title: Wire stop for multi-strand steel cable

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
     [0001] The present application claims priority in the following prior United States Provisional Patent Applications: Serial No. 60/407,773 filed on Sep. 3, 2002; Serial No. ______ filed on ______; and Serial No. 60/472,477 filed on May 22, 2003. 
    
    
     
       TECHNICAL FIELD  
       [0002] The present invention relates generally to rigging and in particular relates to a cable attachment for securing steel cable to trees, power poles, and the like.  
       BACKGROUND OF THE INVENTION  
       [0003] In the field of rigging, it is often necessary to secure one pole to another or to secure one part of a tree to the remainder the tree or to simply secure a tree against falling over. To provide this kind of structural support, it is known to attach one end of a cable to the tree or pole to be supported and the other end of the cable to another object. However, the mechanics of attaching the cable to a tree or pole can present certain technical difficulties in the field.  
       [0004] In such an application, steel cables, such as multi-strand steel cables, typically have been used and are still used today to support trees, power poles and similar items. Such cables are typically attached to a tree or utility pole by attaching a J-hook or lag bolt that is screwed into the tree or pole. A thimble and a “preformed wrap” is attached to the J-hook. Alternatively, the steel cable can be bent around the J-hook and the thimble then secured with “bulldog clips”. Alternatively, the steel cable is attached using eye bolts installed through the tree or pole and secured in like manner.  
       [0005] The above described attachment techniques suffer from requiring multiple parts to secure the steel cable. Also, because of the multiple parts involved, the collection of the multiple parts is only as strong as the weakest of the parts, which in this case typically tends to be the lag bolts or J-hooks, the preformed wraps, or the bulldog clips. These attachment techniques also tend to be difficult to use in close quarters, such as when the trunks of a tree are closer together than about three feet or so.  
       [0006] Accordingly, it can be seen that a need yet remains in the art for a device for attaching steel cable to trees and poles, which device is strong, easily used in the field, compact, and with few parts. It is to the provision of such a device at the present invention is primarily directed.  
       SUMMARY OF THE INVENTION  
       [0007] Briefly described, in a first preferred form the present invention comprises a wire stop for use with a multi-strand steel cable for securing trees and poles. The wire stop includes an outer body with a tapered opening extending therethrough. The wire stop also includes a tapered inner body with a central bore extending therethrough for receiving a single strand of the multi-strand steel cable therein. The tapered inner body is sized and configured to be received in and cooperate with the tapered opening in outer body. With this construction, the multi-strand steel cable can be partially unwound and a single strand threaded through the central bore in the tapered inner body and the remaining strands can be threaded between the inner body and the outer body. Upon the application of a tensile force on the cable, the cable is held fast by the wire stop. Preferably, the tapered inner body is frustoconical in shape. Alternatively, the central bore could be omitted and the central strand of the cable could join the others in the periphery around the tapered inner body.  
       [0008] In another preferred form, the present invention comprises a wire stop for use with a multi-strand steel cable and includes an outer body with a central opening extending therethrough and a plurality of cable engaging wedges. The wedges are sized and adapted to be received in the central opening. The central opening and/or the plurality of cable engaging wedges are tapered so as to clamp the cable engaging wedges tightly to the steel cable when a tensile load is placed on the cable. Preferably, the central opening is tapered and outer surfaces of the plurality of cable engaging wedges are similarly tapered. Also preferably, there are two wedges. Most preferably, the wedges, when considered collectively, are generally frustoconical in shape. Alternatively, an upper collar can be initially secured to the steel cable using a threaded fastener to help secure the wedges within the outer body until a substantial tensile load is placed on the steel cable.  
       [0009] In yet another preferred form of the invention, the invention comprises a wire stop for use with a multi-strand steel cable. The wire stop includes a ferrule having a central bore extending therethrough for receiving a steel cable therein. The ferrule is provided with a plurality of threaded fasteners threaded therein and which extend toward the central bore for securing the steel cable within the ferrule. Preferably, three such threaded fasteners are provided in the form of setscrews. Also preferably, the threaded fasteners are oriented at an oblique angle relative to the central bore to improve the “bite” of the threaded fasteners against the steel cable within the bore.  
       [0010] The present invention allows for a more finished appearance, at low cost, with less clutter. It also is easy to install in the field and provides a very secure attachment of a steel cable to a tree or pole. Also, because of the compactness of the attachment, it can be used in places that heretofore were generally not suitable for the prior art attachment arrangements. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWING FIGURES  
     [0011]FIG. 1 is a side, sectional view of a wire stop according to a first preferred form of the invention, showing strands of a multi-strand steel cable extending therethrough. FIG. 2 is an end view of the wire stop of FIG. 1, showing strands of a multi-strand steel cable extending therethrough. FIG. 3A is an end view of an inner portion of the wire stop of FIG. 1 and FIG. 3B is a side view of that inner portion. FIG. 4A is an end view of an outer portion of the wire stop of FIG. 1 and FIG. 4B is a side view of that outer portion.  
     [0012]FIG. 5 is a side view of a wire stop according to a second preferred form of the invention, showing a multi-strand steel cable extending therethrough. FIG. 6A is side, sectional view of the wire stop of FIG. 5, with an external collar portion thereof omitted. FIG. 6B is an end, sectional, schematic view of a portion of the wire stop of FIG. 5, showing a multi-strand cable (schematically) and a pair of cable-engaging wedge portions of the wire stop.  
     [0013]FIG. 7 is a schematic side view of a wire stop according to a third preferred form of the invention, showing a multi-strand steel cable extending therethrough. FIG. 8 is an end view of the wire stop of FIG. 7. FIG. 9 is a side, sectional view of the wire stop of FIG. 7, showing a perpendicular threaded fastener configuration. FIG. 10 is a side, sectional view of the wire stop of FIG. 7 in a modified or alternative form, showing an angled threaded fastener configuration. 
    
    
     DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS  
     [0014] The present invention may be understood more readily by reference to the following detailed description of the invention taken in connection with the accompanying drawing figures, which form a part of this disclosure. It is to be understood that this invention is not limited to the specific devices, methods, conditions or parameters described and/or shown herein, and that the terminology used herein is for the purpose of describing particular embodiments by way of example only and is not intended to be limiting of the claimed invention. Also, as used in the specification including the appended claims, the singular forms “a,” “an,” and “the” include the plural, and reference to a particular numerical value includes at least that particular value, unless the context clearly dictates otherwise. Ranges may be expressed herein as from “about” or “approximately” one particular value and/or to “about” or “approximately” another particular value. When such a range is expressed, another embodiment includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms another embodiment. Moreover, while the invention is described in connection with the use of multi-strand steel cable, it will be recognized that the invention is not limited to such use and that other types of cable, wire, and the like can be used with the present invention.  
     [0015] With reference now to the drawing figures, a wire stop  100  according to a first preferred form of the invention is shown in FIG. 14B. The wire stop  100  includes an outer body  102  defining a tapered opening defined by tapered surface  104  extending therethrough. Although the depicted embodiment has a hexagon shaped outer body  102 , those skilled in the art will recognize that other shapes can be employed, such as round, rectangular, etc. Indeed, these alternative shapes are within the scope of the present invention. The shape and the size of the outer body  102  may depend on the intended use of the wire stop  100 . In the preferred embodiment illustrated in these figures, the outer body  102  is formed to be secured on the outer portion of the structure being rigged, such as for example a pole or tree. Alternatively, the outer body  102  can be set partially within a counter bore or otherwise inlet into the structure being rigged. Preferably, the outer body  102 , and the other parts of the wire stop  100 , are made of a corrosion-resistant steel or other suitable material. The applicant has found aluminum to work well for either or both the outer body and the inner body. While steel has high strength, the softer aluminum provides a very good grip while minimizing the tendency to cut or break the strands of the cable. Also, the applicant has found that the use of a steel outer body and an aluminum inner body (or vice versa) works very well also. It is also possible to use brass or other materials for some or all of the wire stop.  
     [0016] The wire stop  100  also includes a tapered inner body  106 . The tapered inner body  106  is sized and configured to be received in and cooperate with the tapered opening  104  in the outer body  102 . In the depicted embodiment, the inner body  106  has a complementary frustoconical shape to be closely received within the opening  104  of the outer body  102 . Alternatively, the cross-sectional shape of the inner body  106  may be triangular, rectangular, or oblong variations of such, so long as the inner body  106  is shaped and/or sized to be substantially receivable within the tapered opening of the outer body  102 . It is preferred, but not required, that the inner body  106  includes a central bore  108  extending therethrough for receiving the central strand S 1  of the multi-strand steel cable C therein. Alternatively, the central bore  108  can be omitted from the inner body  106 .  
     [0017] In using the wire stop  100  to attach a multi-strand steel cable to a tree or pole, the multi-strand steel cable C can be partially unraveled and the individual strands can be threaded into the wire stop  100 . Preferably, the central strand S 1  is threaded through the central bore  108  in the tapered inner body  106 , and the outer strands S 2 -S 7  are slipped between the inner body  106  and the outer body  102 . Upon the application of a tensile force on the cable, the strands pull the inner body  106  into the outer body  102 , whereby the cable is held fast in a static state by the wire stop  100 . Preferably, the outer body  102  and the inner body  106  are fabricated from stainless steel or other high strength metals that are durable and resistant to corrosion. However, it is possible to incorporate other less durable materials for rigging procedures demanding less durability and corrosion resistance, so long as the material will maintain the tensile load applied upon it.  
     [0018] Referring now to FIGS.  5 - 6 B, a wire stop  200  is shown according to another preferred form of the present invention for use with a multi-strand steel cable C. The wire stop  200  includes an outer body  202  with a central opening  204  extending therethrough. Preferably, the opening  204  is formed to be tapered and to have a minimum diameter slightly larger than the cable to be inserted therein. A pair of cable-engaging wedges  206 ,  207  are sized and shaped to receive a cable extending therein. The wedges  206 ,  207  are also sized and adapted to be received in the central opening and have an outer taper that corresponds to the inner taper of the central opening  204 . Furthermore, the wedge, considered collectively, are generally frustoconical in overall shape and when placed together define an inner aperture extending axially therealong for receiving the cable C therein. For example, the central opening  204  and/or the wedges  206 ,  207  are tapered so as to clamp the wedges tightly to the cable when a tensile load is placed on the cable. In the depicted embodiment, the central opening  204  is tapered and the outer surfaces of the cable engaging wedges are similarly tapered. Although the depicted embodiment shows two wedges, the incorporation of three or more wedges is within the scope of the present invention. Optionally, the inner surfaces of the wedges  206 ,  207  can be provided with a slip-resistant surface texture or include protrusions which further prevent slippage of the cable under load. Similar to the embodiment of FIG. 14, the parts of the wire stop  200  can be made from steel, aluminum, brass, or other suitable material.  
     [0019] Referring still to FIG. 5, optionally, an upper collar  212  is provided and can be secured to the cable C as a temporary means of holding the wire stop  200  together and in place. The collar  212  preferably is secured to the cable C by way of a threaded faster  214 . The collar  212  secures the wedges within the outer body  202  until a substantial tensile load is placed upon the cable C.  
     [0020] Referring now to FIGS.  7 - 10 , yet another preferred form of the invention is shown, comprising a wire stop  300 . The wire stop  300  has cylindrical body or ferrule  302  defining a central bore  304  extending axially therethrough. In the preferred exemplary embodiment depicted, the ferrule  302  is provided with three threaded fasteners  306 ,  307  and  308  threaded into the ferrule and which extend radially toward the central bore  304  for securing the steel cable C within the ferrule  302 . In a preferred embodiment, the fasteners  306 ,  307  and  308  are positioned to be substantially perpendicular in relation to the bore  304 . Similar to the embodiment of FIG. 14, the parts of the wire stop  200  can be made from steel, aluminum, brass, or other suitable material.  
     [0021] Alternatively, as shown in FIG. 10, the fasteners  306 ,  307  and  308  are oriented at an oblique angle α relative to the central bore, in order to improve the “bite” of the fasteners  306 ,  307  and  308  against the cable C within the bore  304 . Preferably, the angle α is within several degrees of perpendicular so that a little extra grip is placed on the cable without creating too great a tendency to cut the cable with the edge of the fastener. Although three fasteners are preferred and shown in the figures, the inclusion of fewer or greater numbers of fasteners is within the scope of the present invention. Upon insertion of the cable C within the bore  304  of the ferrule  302 , the fasteners are tightened to secure the cable within the bore, and the cable is held fast despite a tensile force applied upon it.  
     [0022] While the invention has been described with reference to preferred and exemplary embodiments, it will be understood by those skilled in the art that a variety of modifications, additions and deletions can be made therein without departing from the spirit and scope of the invention, as defined by the following claims.