Device and method for trenchless replacement of underground pipe

Abstract

The basic features of the invention include a pipe parting mole, a length of cable that is engagable to the mole, a cable pulling device and a cable pulling device engagement means that provides a mounting structure for the cable pulling device. The cable pulling device engagement means generally includes a reaction plate and a structure for removably engaging the cable pulling device therewithin. A cable pulling frame may be advantageously used to facilitate the removal of the cable from a relatively small hole that is created at the pulling end of the pipe.

1 . A device for the trenchless replacement of in-situ pipe, comprising: 
 a mole;    a length of cable, said cable being engagable to said mole;    a cable pulling device being releasably engagable to said cable;    a cable pulling device mounting frame being releasably engagable to said cable pulling device; and wherein said cable pulling device is a post tensioning ram (PTR).    
   
   
       2 . A device as described in  claim 1  wherein said cable pulling device includes at least one pair of cable engaging collets that function to engage said cable on a said pulling stroke and to release said cable on a said recovery stroke; and wherein-at least one further pair of collets is provided that function to engage said cable on said recovery stroke and release said cable on said pulling stroke.  
   
   
       6 . A device as described in  claim 2  wherein said further pair of collets is engaged within said cable pulling device.  
   
   
       7 . A device as described in  claim 6  wherein said cable pulling device is formed with a slotted cable insertion means for the sideways insertion of said cable within said cable pulling device.  
   
   
       14 . A device for the trenchless replacement of in-situ pipe, comprising: 
 a mole;    a length of cable, said cable being engagable to said mole;    a cable pulling device;    a cable pulling device mounting frame being releasably engagable to said cable pulling device wherein said cable pulling device mounting frame includes an annulus member including a cable passage bore formed therethrough and a cable insertion slot formed through portions of said annulus member for the sideways insertion of said cable within said cable passage bore of said annulus member.    
   
   
       15 . A device as described in  claim 14  wherein said annulus member includes a cable pulling device holding means for releasably holding a portion of said cable pulling device therewithin.  
   
   
       16 . A device as described in  claim 14  wherein said cable pulling device mounting frame includes a reaction plate having an enlarged surface for disbursing a reaction force against a cable pulling force generated by said cable pulling device.  
   
   
       17 . A device as described in  claim 16  wherein said annulus member is mountable in relation to said reaction plate such that said reaction plate disburses cable pulling forces exerted on said annulus by said cable pulling device.  
   
   
       26 . A device for the trenchless replacement of in-situ pipe, comprising: 
 a mole;    a length of cable, said cable being engagable to said mole;    a cable pulling device including a cable engagement mechanism and a cable pulling device engagement means functioning to provide a mounting structure for said cable pulling device;    said cable pulling device engagement means further including a reaction plate having an enlarged surface for disbursing a reaction force against a cable pulling force generated by said cable pulling device, and    a cable pulling frame, said cable pulling frame being mountable to said reaction plate and said cable pulling device being mountable to said cable pulling frame.    
   
   
       30 . A mole for use in the trenchless replacement of in-situ pipe, comprising, a nose portion being engagable to a cable, a tapered body portion and a replacement pipe engagement portion, said mole further including at least one blade, said tapered body portion acting to expand said in-situ pipe for the replacement thereof with a length of replacement pipe, and said blade acting to cut pipe engagement devices encountered by said mole after said pipe has been expanded by said tapered body portion.  
   
   
       33 . A mole as described in claim  31  wherein a threaded bore is formed within said mole, and wherein a mole engagement fixture is fixedly engaged to an end of said cable, said fixture including a threaded end portion that is threadably engagable with said threaded bore.  
   
   
       34 . A mole as described in  claim 34  wherein said fixture further includes a hex nut portion integrally formed therewith and provided for the tightening of said threaded portion within said threaded bore.  
   
   
       36 . A cable pulling device engagement frame comprising: 
 an annulus member including a cable passage bore formed therethrough and a cable insertion slot formed through portions of said annulus member for the sideways insertion of a cable within said cable passage bore of said annulus member;    a reaction plate having an enlarged surface for disbursing a reaction force against a cable pulling force generated through said annulus member.    
   
   
       37 . A frame as described in  claim 36  wherein said frame includes two cable pulling device engagement devices, such that two cable pulling devices can operationally function with said frame to pull two cables simultaneously.  
   
   
       38 . A device as described in  claim 37  wherein two annulus members function as said engagement devices to engage said two cable pulling devices.  
   
   
       39 . A device as described in  claim 38  wherein the two annulus members are angularly disposed relative to each other, such that two cable pulling devices are operationally engaged therewith.  
   
   
       40 . A method for the trenchless replacement of in-situ pipe, comprising the steps of: 
 exposing a first end of said pipe;    exposing a second end of said pipe;    disposing a pulling cable through said pipe between said first end and said second end;    engaging a mole to said cable at said first end;    engaging a cable pulling device to said cable at said second end; and    installing a reaction plate at said second end after said cable is disposed through said pipe, and    pulling said mole through said pipe utilizing said cable pulling device.    
   
   
       41 . A method as described in  claim 40  wherein said second end is exposed within an excavated hole, and wherein a reaction plate is disposed against a sidewall of said hole.  
   
   
       42 . A method as described in  claim 41 , further including the installation of a cable pulling device engagement frame between said reaction plate and said cable pulling device after said cable is disposed through said pipe.  
   
   
       43 . A method as described in  claim 42  wherein said frame includes a pulley for changing the direction of said cable.  
   
   
       44 . A method as described in  claim 43  wherein said cable pulling device is disposed within said hole.  
   
   
       45 . A method as described in  claim 43  wherein said frame and said cable pulling device are disposed within said hole.  
   
   
       46 . A method as described in  claim 40 , including the further steps of: 
 engaging said cable with a first pair of collets on a cable pulling stroke of said cable pulling device, and    engaging said cable with a second pair of collets on a recovery stroke of said cable pulling device.    
   
   
       47 . A method as described in  claim 40  wherein said cable pulling device is a post tensioning ram (PTR).