Image Number 3 for United States Patent #6382877.
The invention concerns the replacement of underground pipes (52) wherein a former/cutting blade device (10) is pulled along the line of the existing pipe (52) by a cable fed (30) previously into the existing pipe (52). As the device (10) is so pulled it cuts and spreads the existing pipe (52). At the same time a new pipe (26) attached to the rear of the former (12) is pulled into place. The invention is of particular use in the replacement of small size lead water pipes which lead to consumer dwellings, and provides that the cable (30) which must be as large a diameter as possible to take the loads involved, is connected to the former (12) by having a ferrule (28) at one end which is located in a recess (27) in the former (12) so as not to interfere with the former profile. Also, the recess (27) is to the rear of the cutting blade (40) so that the ferrule (28) does not to cause an obstruction to the cutting operation.