Abstract:
A method for installing a wedge connector positioned between two conductive cables includes connecting a head coupler portion of a disconnect assembly to a wedge frame, wherein the head coupler portion includes an extension rod within a longitudinal bore; positioning the wedge frame and a first end of the extension rod against the wedge connector; connecting the head coupler portion to a tool coupler portion of the disconnect assembly, wherein the tool coupler portion is connected to a hydraulic drive tool that includes a ram; causing the hydraulic drive tool to apply force to a second end of the extension rod, wherein applying the force to the second end causes the first end to apply force to the wedge connector; and disconnecting the head coupler portion from the tool coupler portion.

Description:
RELATED APPLICATION 
     This application is a divisional of and claims priority to U.S. application Ser. No. 13/711,726 filed on Dec. 12, 2012, which claims priority to U.S. Provisional Patent Application No. 61/584,360, filed Jan. 9, 2012, the disclosures of which are hereby incorporated by reference. 
    
    
     BACKGROUND INFORMATION 
     In electrical power systems it is occasionally necessary to tap into an electrical power line. One known system for tapping into an electrical power line is to use a tap connector for electrically connecting a mainline electrical cable to an end of a tap line electrical cable. One such tap connector, referred to as a wedge connector, includes a conductive C-shaped member and a wedge. To install the wedge connector, two cables are positioned at opposite sides of the C-shaped member and the wedge is driven between the two cables. Insertion of the wedge forces the two cables against the C-shaped member to provide a secure conductive contact. 
     Wedge connectors have conventionally been installed using explosively-driven connecting tools to drive the wedge. More recently, battery-operated hydraulic tools have been introduced to install wedge connectors. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  provides an isometric view of a hydraulic tool in which apparatus and methods described herein may be implemented; 
         FIG. 2  provides a view of the hydraulic tool of  FIG. 1  including a disconnect assembly according to an implementation described herein; 
         FIG. 3  provides a cross sectional view of a head coupler of the disconnect assembly of  FIG. 2 ; 
         FIG. 4  provides a cross sectional view of a tool coupler of the disconnect assembly of  FIG. 2 ; 
         FIG. 5  provides a cross sectional view of the disconnect assembly of  FIG. 2  in a coupled configuration; 
         FIG. 6  provides a side view of the disconnect assembly of  FIG. 2 , in a coupled configuration, installed between the hydraulic tool and wedge frame of  FIG. 1 ; 
         FIG. 7  is a flowchart of an exemplary process for installing a wedge connector using a hydraulic installation tool and a disconnect assembly, according to an implementation described herein; and 
         FIGS. 8A-8C  provide isometric views of a wedge connector installation process according to an implementation described herein. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     The following detailed description refers to the accompanying drawings. The same reference numbers in different drawings may identify the same or similar elements. Also, the following detailed description does not limit the invention. 
     Battery-operated hydraulic tools for installing wedge connectors provide several advantages over explosively-driven tools. For example, use of the hydraulic tools may simplify or eliminate some safety, transport, and certification concerns associated with explosively-driven installation tools. However, the hydraulic tools create a unique set of challenges for users. For example, as shown in  FIG. 1 , a wedge installation tool  10  may include a hydraulic driver  100 , an interchangeable wedge frame  110  (also referred to as a “head”), and a ram  120 . 
     Wedge frame  110  may be a conventional tool head, such as a tool head used by manufactures for securing wedge connectors at relatively low (e.g., non-ballistic) ram velocities. Wedge frame  110  may be sized for different wedge connectors (e.g., depending on the thickness of mainline and tap electrical cables). Positioning of wedge frame  110  (e.g., to hold a wedge during installation) can be cumbersome due to the size or weight of hydraulic driver  100  and the fact that wedge frame  110  is screwed directly to hydraulic driver  100 . Particularly, hydraulic driver  100  and wedge frame  110  must be maneuvered into position between the mainline and tap conductor, and then rotated to snug ram  120  against the wedge prior to activation of hydraulic driver  100  to advance ram  120 . 
       FIG. 2  provides a view of wedge installation tool  10  including a disconnect assembly  200  installed on wedge installation tool  10 . According to an implementation described herein, disconnect assembly  200  is provided to allow wedge frame  110  to be positioned and snug against a wedge of a wedge connector prior to connecting wedge frame  110  to hydraulic driver  100 . As shown in  FIG. 2 , disconnect assembly  200  may include a head coupler  210  and a tool coupler  220 . Head coupler  210  may include an extension rod  212  and a threaded section  214  configured to receive one of wedge frames  110 . Two wedge frames  110  are shown in  FIG. 2 , and either of the two wedge frames  110  may be interchangeably used with head coupler  210 . As described further herein, tool coupler  220  may include a threaded section to connect to hydraulic driver  100  and a section to secure head coupler  210  to tool coupler  220 . Head coupler  210  and tool coupler  220  may be generally be made from a metal alloy, such as SAE grade 4140 steel. Extension rod  212  may be made of a corrosion resistant metal, such as stainless steel. 
       FIG. 3  provides a cross sectional view of an exemplary implementation of head coupler  210 . Cross-sectional hatching is excluded from  FIG. 3  for simplicity. As shown in  FIG. 3 , head coupler  210  may include extension rod  212  within a cylindrical bore  302  and threaded section  214 . Cylindrical bore  302  may include a first portion  304  with a diameter configured to contain a spring  306  around the circumference of extension rod  212  and to receive ram  120  from hydraulic driver  100 . Cylindrical bore  302  may include a second portion  308  with a smaller diameter to permit travel of extension rod  212  within cylindrical bore  302  with minimal clearance. A shoulder  310  may be formed at the interface of first portion  304  and second portion  308 . 
     Extension rod  212  may include a cylindrical member to transfer force from ram  120  to a wedge. Forces transferred from ram  120  may be in the range of between three to eight tons. Extension rod  212  travels axially within cylindrical bore  302 . Extension rod  212  may include a proximal end  312  to receive applied force from ram  120  and a distal end  314  that may extend out of cylindrical bore  302 . Proximal end  312  may include a large diameter portion  316  (also referred to as support rim  316 ) that conforms generally (e.g., with an appropriate clearance) to the diameter of first portion  304  of cylindrical bore  302 . Spring  306  may generally encircle a portion of extension rod  212  within first portion  304  of cylindrical bore  302 . Spring  306  may provide a retention force (e.g., axially along cylindrical bore  302 ) to retain extension rod  212  within cylindrical bore  302 . Spring  306  may be constrained between shoulder  310  of cylindrical bore  302  and support rim  316  of proximal end  312 . The axial force of spring  306  may be much smaller than a force applied to extension rod  212  by ram  120 . Upon application of force from ram  120 , spring  306  may be compressed between shoulder  310  and support rim  316 . Travel of extension rod  212  may be limited to the length of first portion  304  minus the length of compressed spring  306  when compressed between shoulder  310  and support rim  316 . 
     Distal end  314  may include a threaded bore  318  to accommodate an end cap  320 . For example, end cap  320  may be screwed into threaded bore  318 . End cap  320  may include a diameter larger than the diameter of second portion  308  and approximately equal to an outer diameter of first portion  304  of cylindrical bore  302 . Because end cap  320  has a larger diameter than second portion  308  of cylindrical bore  302 , end cap  302  may limit axial travel of extension rod  212  in a direction toward large diameter portion  316  such that the proximal end  312  does not extend beyond the end of first portion  304  of cylindrical bore  302 . An exposed surface of end cap  320  may engage another surface (e.g., a wedge) to apply force supplied by ram  120  on proximal end  312 . In another implementation, end cap  320  may include a non-flat surface for to enable alternate functions for disconnect assembly  200  (e.g., functions other than forcing a wedge of a wedge connector). For example, in other embodiments, end cap  320  may include a cutting edge or a crimping surface. 
     Head coupler  210  may also include multiple annular protrusions  322 - 1  through  322 - 5  (also referred to herein as a “protrusion ring” or collectively as “protrusion rings  322 ”) around a circumference of head coupler  210 . Protrusion rings  322  may be configured to engage corresponding grooves (e.g., grooves  424 , described below in connection with  FIG. 4 ) of tool coupler  220  to restrict axial motion of head coupler  210  with respect to tool coupler  220 . Thus, protrusion rings  322  may be load bearing against a reaction to a force applied by ram  120  and/or extension rod  212 . Although five protrusion rings  322  are shown, in other implementations, more or fewer protrusion rings  322  may be used, depending, for example, upon the expected loads applied by hydraulic driver  100 . In one implementation, one or more protrusion rings  322  and corresponding grooves  424  may be of different sizes (e.g., mechanically indexed) to prevent partial insertion or misalignment of head coupler  210  within tool coupler  220 . For example, as shown in  FIG. 3 , protrusion ring  322 - 5  may have a wider surface than any of protrusion rings  322 - 1  through  322 - 4 . In one implementation, the section of head coupler  210  encircled by protrusion rings  322  may be cylindrical to allow insertion of head coupler  210  into tool coupler  220  in any rotational orientation around the axis of the longitudinal bore  302 . 
       FIG. 4  provides a cross sectional view of tool coupler  220  according to an implementation described herein. Cross-sectional hatching is excluded from  FIG. 4  for simplicity. As shown in  FIG. 4 , tool coupler  220  may include a tool engagement section  410 , a head engagement section  420 , and a retention system  430 . Tool engagement section  410  may include a threaded bore  412  to connect to hydraulic driver  100 . Threaded bore  412  may be sized to match the diameter and threads of wedge frame  110 , such that tool coupler  220  may be threaded onto hydraulic driver  100  in place of wedge frame  110 . 
     Head engagement section  420  may include a U-shaped channel  422 . U-shaped channel  422  may include multiple grooves  424 - 1  through  424 - 5  (referred to collectively herein as “grooves  424 ”) and may be sized to receive head coupler  210  with multiple protrusion rings  322 - 1  through  322 - 5 . Grooves  424  may be configured to engage corresponding protrusion rings  322  of head coupler  210  (e.g., when head coupler  210  is connected to tool coupler  220 ) to restrict axial motion of head coupler  210  with respect to tool coupler  220 . In one implementation, one or more grooves  324  and corresponding protrusion rings  322  may be of different sizes (e.g., mechanically indexed) to prevent partial insertion or misalignment of head coupler  210  within tool coupler  220 . For example, as shown in  FIG. 3 , grooves  424 - 5  may have a wider surface than any of grooves  424 - 1  through  424 - 4 . 
     Retention system  430  may include a mechanism to lock head coupler  210  within tool coupler  220 . In one implementation, a spring-loaded latch  432  may allow insertion of head coupler  210  into tool coupler  220  and snap into place over head coupler  210  after head coupler  210  is fully inserted within tool coupler  220 . Thus, retention system  430  may provide an automatic or “hands-free” mechanism to secure head coupler  210  in tool coupler  220  and keep cylindrical bore  302  aligned with threaded bore  412 . After head coupler  210  has been inserted in tool coupler  220  and spring-loaded latch  432  has snapped into a securing position, a spring-loaded pin  434  may secure spring-loaded latch  432  in place to prevent head coupler  210  from forcing off spring-loaded latch  432 . Spring-loaded pin  434  may be manually disengaged from spring-loaded latch  432  to allow spring-loaded latch  432  to lift up and release head coupler  210  from tool coupler  220 . Thus, manual (e.g., operator) intervention may be required to disengage retention system  430 . 
     In another implementation, retention system  430  may include a different locking system, such as one or more retention pins that may be inserted transversely across a portion of U-shaped channel  422  after head coupler  210  has been inserted within tool coupler  220 . In one implementation, transversally-mounted retention pins may also be spring loaded. Generally, retention system  430  may be required to prevent head coupler  210  in tool coupler  220  from separating when in an unloaded state (e.g., when forces are not being applied by ram  120 ). In a loaded state, the extension of ram  120  into cylindrical bore  302  would prevent cylindrical bore  302  and threaded bore  412  form becoming misaligned. 
       FIG. 5  provides a cross section view of disconnect assembly  200  in a coupled configuration. As shown in  FIG. 5 , head coupler  210  is engaged within U-shaped channel  422  of tool coupler  220 . U-shaped channel  422  and head coupler  210  may include corresponding indexing interfaces to ensure a proper connection and to prevent axial motion of head coupler  210  with respect to tool coupler  220 . More particularly, each of grooves  424 - 1  through  424 - 5  may engage a corresponding protrusion ring  322 - 1  through  322 - 5  of head coupler  210 . While the indexing interfaces shown in  FIG. 5  are described in the context of rings  322  on head coupler  510  and grooves  424  on tool coupler  220 , it other implementations, the indexing interface may include different configurations (e.g., rings on tool coupler  510  and grooves on head coupler  220 ). Cylindrical bore  302  aligns with threaded bore  412  such that ram  120  of hydraulic driver  100  (not shown in  FIG. 5 ) may advance through first portion  304  of cylindrical bore  302  and into second portion  308  of cylindrical bore  302  to apply force to proximal end  312  of extension rod  212 . Distal end  314  of extension rod  212  may extend out of the second portion  308  of cylindrical bore  302 , causing end cap  320  to contact, for example, a wedge connector (not shown). 
       FIG. 6  provides an image of disconnect assembly  200  installed between hydraulic driver  100  and wedge frame  110 . As shown in  FIG. 6 , spring-loaded latch  432  of retention system  430  locks head coupler  210  within U-shaped channel  422  of tool coupler  220  to prevent inadvertent disengagement of head coupler  210  and tool coupler  220 . In one implementation, head coupler  210  may rotate (e.g., along the common axis shared by extension rod  212  and cylindrical bore  302 ) within U-shaped channel  422  of tool coupler  220 . This rotation may allow, for example, simple adjustment of an orientation of wedge frame  110  when wedge frame  110  is threaded onto threaded section  214  of head coupler  210 . For example, the depth of insertion of the threaded section  214  can be adjusted (e.g., to position end cap  320  in contact a wedge connector prior to activation of ram  120 ) when head coupler  210  is disconnected from tool coupler  220 . Additionally, the depth of insertion of the threaded section  214  may be adjusted when head coupler is connected to tool coupler  220  without requiring rotation of hydraulic driver  100 . 
       FIG. 7  is a flowchart of an exemplary process  700  for installing a wedge connector using a hydraulic installation tool and a disconnect assembly, according to an implementation described herein. Process  700  is described below with reference to  FIGS. 8A-8C , which show isometric views of some of installation process  700 . Process  700  may include threading a tool coupler of the disconnect assembly onto an installation tool (block  710 ). For example, as shown in  FIG. 8B , tool coupler  220  of disconnect assembly  200  may be threaded onto hydraulic driver  100 . Tool coupler  220  may engage with hydraulic driver  100  such that ram  120  (not visible in  FIG. 8B ) of hydraulic driver  100  will have a channel to extend through when activated. In one implementation, tool coupler  220  may be threaded (and/or otherwise secured) to hydraulic driver  100  as a vendor process and provided to a user as a pre-configured assembly. 
     Process  700  may further include threading a head coupler of a disconnect assembly onto a wedge frame (block  720 ) and positioning the wedge frame on a wedge connector between a main electrical line and a tap line (block  730 ). For example, as shown in  FIG. 8A , head coupler  210  of a disconnect assembly  200  may be threaded into wedge frame  110 . A wedge connector  810  may be positioned on a main electrical line  820  and a tap line  830 . Wedge frame  110  may be positioned to engage wedge connector  810 . Wedge frame  110  may be selected, for example, from multiple-sized wedge frames  110  (e.g., based on the cable size of electrical line  820  and tap line  830 ). Head coupler  210  may be threaded further into wedge frame  110  so that end cap  320  may engage wedge  810 . 
     Process  700  may further include connecting the head coupler to the tool coupler (block  740 ). For example, as shown in  FIG. 8C , tool coupler  220  may be mated with head coupler  210  to form single disconnect assembly  200 . Retention system  430  may snap into place to prevent inadvertent separation of head coupler  210  from tool coupler  220 . 
     Process  700  may also include extending a ram from the installation tool to apply force to a rod of the disconnect assembly block ( 750 ), and retracting the ram (block  760 ). For example, as shown in  FIG. 8C , an operator may depress activation trigger  840  of hydraulic driver  100  to cause ram  120  to extend through tool coupler  220  and engage extension rod  212 . Extension rod  212  may extend out of cylindrical bore  302  forcing end cap  320  to apply a force to wedge connector  810 . After wedge connector  810  has been forced completely into position, an operator may depress retraction trigger  850  of hydraulic driver  100  to cause ram  120  to retract out of head coupler  210  and tool coupler  220 . 
     Process  700  may further include disconnecting the head coupler from the tool coupler (block  770 ), and removing the head coupler from the wedge frame (block  780 ). For example, an operator may release retention system  430  to allow head coupler  210  and tool coupler  220  to be disconnected. Head coupler  210  may be unscrewed from wedge frame  110  in the event head coupler may need to be affixed to a different sized wedge frame  110  in the future. 
     According to implementations described herein, a disconnect assembly is provided to allow a wedge frame to be positioned and snug against a wedge prior to connecting the wedge frame to a hydraulic driver. In one implementation the disconnect assembly may include a head coupler portion and a tool coupler portion. The head coupler portion may include a threaded portion on a first part of an exterior surface to connect to a wedge frame, a longitudinal bore, a rod configured to slide longitudinally within the longitudinal bore, and a set of annular protrusions on a second part of the exterior surface. The tool coupler portion may include a threaded bore configured to mechanically attach the tool coupler portion to the tool, and a channel to receive a head coupler portion. The channel may include a set of grooves corresponding to the set of annular protrusions on the head coupler portion. When the head coupler portion is connected to the tool coupler portion, a ram from the hydraulic tool may engage the rod to apply force to an object in the wedge frame. 
     The foregoing description of exemplary implementations provides illustration and description, but is not intended to be exhaustive or to limit the embodiments described herein to the precise form disclosed. Modifications and variations are possible in light of the above teachings or may be acquired from practice of the embodiments. 
     Although the invention has been described in detail above, it is expressly understood that it will be apparent to persons skilled in the relevant art that the invention may be modified without departing from the spirit of the invention. Various changes of form, design, or arrangement may be made to the invention without departing from the spirit and scope of the invention. Therefore, the above mentioned description is to be considered exemplary, rather than limiting, and the true scope of the invention is that defined in the following claims. 
     No element, act, or instruction used in the description of the present application should be construed as critical or essential to the invention unless explicitly described as such. Also, as used herein, the article “a” is intended to include one or more items. Further, the phrase “based on” is intended to mean “based, at least in part, on” unless explicitly stated otherwise.