End Fitting for a Cable Bolt Assembly

Abstract

A cable bolt assembly is disclosed comprising a cable bolt having a shaft, an end fitting disposed on the shaft and including an end fitting body. Mechanical interlocking is provided between the body and the shaft to form a connection therebetween. The mechanical interlocking may be formed directly between the body and the shaft and/or by engagement formations disposed intermediate the body and shaft. The body further including an exterior profiling arranged to engage a further component of the end fitting to install and/or tension the cable bolt assembly in use. A method of forming the cable bolt assembly is also disclosed.

1 . A cable bolt assembly comprising:
 a. a cable bolt having a shaft;   b. an end fitting disposed on the shaft and including a body extending between a leading end and a trailing end spaced apart along an axis; and   c. mechanical interlocking provided between the body and the shaft to form a connection therebetween;   d. the body including an exterior profiling disposed thereon and arranged to engage a further component of the end fitting to install and/or tension the cable bolt assembly in use.   
     
     
         2 . A cable assembly according to  claim 2 , wherein the mechanical interlocking is provided at least in part by direct connection between the body and the shaft. 
     
     
         3 . A cable bolt assembly according to  claim 1 , wherein at least a portion of the body being formed onto a portion of the shaft so that the body is plastically deformed about the shaft and wherein the mechanical interlocking is formed at least in part by the plastic deformation of the body about the shaft. 
     
     
         4 . A cable bolt assembly according to  claim 3 , wherein the exterior profiling is disposed on at least a portion of the portion of the body that is plastically deformed about the shaft. 
     
     
         5 . A cable bolt assembly according to  claim 1 , wherein the cable bolt includes a plurality of wires wound about a central hollow wire. 
     
     
         6 . A cable bolt assembly according to  claim 1 , further comprising one or more engagement formations provided between an internal surface of the body and the shaft, the one or more engagement formations arranged to engage the shaft and the internal surface of the body and form at least part of the mechanical interlocking between the shaft and the body. 
     
     
         7 . A cable bolt assembly according to  claim 6 , wherein the one or more engagement formations are embedded in at least one of the body and the shaft. 
     
     
         8 . A cable bolt assembly according to  claim 7 , wherein the one or more engagement formations are embedded with both the body and the shaft. 
     
     
         9 . A cable bolt assembly according to  claim 6 , wherein the one or more engaging formations are provided on at least one intermediate member that is disposed between the body and the shaft. 
     
     
         10 . A cable bolt assembly according to  claim 9 , wherein the at least one intermediate member is in the form of a helical winding that extends around the shaft. 
     
     
         11 . A cable bolt assembly according to  claim 1 , wherein the connection between the shaft and the body has a high capacity. 
     
     
         12 . A cable bolt assembly according to  claim 11 , wherein the end fitting breaking load is >60% of the cable bolt uniaxial tensile strength. 
     
     
         13 . A cable bolt assembly according to  claim 1 , wherein the body includes an outer diameter 1.6 times or less an outer diameter of the shaft. 
     
     
         14 . A cable bolt assembly according to  claim 1 , wherein the external profile is an external thread and the assembly further comprises the further component, the further component being in the form of a nut threadedly engageable with the external thread and rotatable about the body to tension the cable in use. 
     
     
         15 . A cable bolt assembly according to  claim 14 , further comprising a washer disposed on the body distal of the nut, the washer being axially displaceable along the body whilst being restrained from rotating about the body. 
     
     
         16 . A cable bolt assembly according to  claim 15 , wherein a keyway is formed between the body and the washer to restrain the washer from rotating about the body. 
     
     
         17 . A cable bolt assembly according to  claim 15 , further comprising a torque transfer arrangement that is arranged to allow a threshold torque to be applied to the shaft through the nut without inducing relative rotation between the nut and the shaft. 
     
     
         18 . A cable bolt assembly according to  claim 17 , wherein the torque transfer arrangement comprises a frangible connection between the washer and the nut. 
     
     
         19 . A cable bolt assembly according to  claim 1 , further comprising a sealant disposed between the body and the shaft. 
     
     
         20 . A method of assembling a cable bolt assembly comprising:
 a. providing an end fitting having a body extending between two ends along an axis;   b. disposing the body onto an end portion of a shaft of a cable bolt;   c. forming the body onto the shaft so that the body is plastically deformed about the shaft; and   d. disposing exterior profiling on the body.