Patent Number: 6,305,880

Title: 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 frame that provides a mounting structure for the cable pulling device. The cable pulling device engagement frame generally includes a reaction plate and an annulus member for removably engaging the cable pulling device with the frame. The frame is configured for the sideways engagement of the cable within the frame and the annulus member. Two pairs of cable engagement collets are preferably utilized; a first pair being disposed within the cable pulling device to engage the cable on a pulling stroke, and a second pair may be disposed within the frame or the cable pulling device to engage the cable on a recovery stroke. The cable pulling device is preferably a post tensioning ram (PTR).

Inventors: Carter; Robert Ward (San Francisco, CA), Carter; Robert Williams (Oakland, CA)

Assignee: WRB Company, Inc.

International Classification: B23D 21/02 (20060101); B23D 21/00 (20060101); E03F 3/00 (20060101); E21B 7/30 (20060101); E03F 3/06 (20060101); E21B 7/00 (20060101); E21B 29/00 (20060101); E21B 29/10 (20060101); E21B 7/20 (20060101); E02F 005/10 (); E03F 003/06 ()

Expiration Date: 10/23/2018