Swivel for use in installing large diameter casing

Abstract

The invention includes a pair of swivels for use with an auger boring machine. One of the swivels allows for rotation of a first auger of a first auger assembly connected to the trailing end of a pilot tube without rotating the pilot tube. The other swivel allows for rotation of a larger diameter second auger connected to the trailing end of the first auger assembly without rotating the first auger. Each of the swivels includes a thrust bearing.

1 . A method comprising the steps of:
 pushing a smaller diameter cylindrical casing forward with a first section of a swivel through an underground hole having a first diameter; and   during the step of pushing, rotating a second section of the swivel, a first cuffing head rearward of the smaller diameter casing and a first auger rearward of the first cutting head relative to the first section and smaller diameter casing to enlarge the underground hole from the first diameter to a second diameter larger than that of the smaller diameter casing.   
   
   
       2 . The method of  claim 1  wherein the first cutting head and first auger are respectively a larger cutting head and a larger auger of a larger auger assembly; and further comprising the steps of rotating a smaller cutting head and smaller auger of a smaller auger assembly to cut the underground hole having the first diameter; and mounting the first section of the swivel on a trailing end of the smaller auger assembly after the underground hole with the first diameter has been cut. 
   
   
       3 . The method of  claim 2  wherein the smaller auger assembly comprises the smaller cylindrical casing; and the step of mounting comprises the step of abutting a trailing edge of the smaller cylindrical casing with the first section of the swivel. 
   
   
       4 . The method of  claim 1  wherein the first cutting head and first auger are respectively a larger cutting head and a larger auger of a larger auger assembly; and further comprising the steps of rotating a smaller cutting head and smaller auger of a smaller auger assembly to cut the underground hole having the first diameter; and wherein the step of rotating the second section of the swivel comprises the step of rotating the larger auger without rotating the smaller auger at the same time. 
   
   
       5 . The method of  claim 4  wherein the step of rotating the smaller cutting head and smaller auger comprises the step of rotating the smaller auger within the smaller diameter casing. 
   
   
       6 . The method of  claim 5  wherein the step of rotating the second section of the swivel comprises the step of rotating the larger auger within a larger diameter cylindrical casing having a diameter larger than that of the smaller diameter casing. 
   
   
       7 . The method of  claim 1  wherein the step of rotating comprises the step of rotating the first auger within a larger diameter cylindrical casing having a diameter larger than that of the smaller diameter casing. 
   
   
       8 . The method of  claim 7  further comprising the step of moving the larger diameter casing forward into the enlarged underground hole. 
   
   
       9 . The method of  claim 8  wherein the swivel is forward of a leading end of the larger diameter casing throughout the steps of rotating and moving. 
   
   
       10 . The method of  claim 7  further comprising the step of rotating a smaller auger within the smaller diameter casing. 
   
   
       11 . The method of  claim 7  wherein the step of rotating comprises the step of rotating the second section rearward of a trailing end of the smaller diameter casing and forward of a leading end of the larger diameter casing. 
   
   
       12 . The method of  claim 7  wherein the step of rotating comprises the step of rotating the second section, first cutting head and first auger with an auger drive which is rearward of a trailing end of the larger diameter casing. 
   
   
       13 . The method of  claim 1  wherein the first cutting head has an outer diameter which is greater than an outermost diameter of the first auger. 
   
   
       14 . The method of  claim 1  further comprising the step of inserting a wall of the first section into the smaller diameter casing so that a cylindrical outer surface of the wall abuts a cylindrical inner surface of the smaller diameter casing. 
   
   
       15 . The method of  claim 14  further comprising the step of abutting a circular trailing edge of the smaller diameter casing with a circular pushing member connected to the inserted wall and extending radially outwardly of the cylindrical outer surface of the wall. 
   
   
       16 . The method of  claim 1  wherein the step of pushing comprises the step of pushing a circular trailing edge of the smaller diameter casing with a circular pushing member of the first section. 
   
   
       17 . The method of  claim 1  wherein the step of rotating comprises the step of rotating the second section, first cutting head and first auger with an auger drive; and further comprising the step of moving the auger drive rearwardly relative to the swivel. 
   
   
       18 . The method of  claim 17  wherein the step of rotating comprises the step of rotating the first auger within a first larger diameter cylindrical casing having a diameter larger than that of the smaller diameter casing; and further comprising, after the step of moving, the steps of connecting a leading end of a second larger diameter cylindrical casing having a diameter the same as that of the first larger diameter casing to a trailing end of the first larger diameter casing; connecting a leading end of a second auger to a trailing end of the first auger; and rotating the first auger within the first larger diameter casing and the second auger within the second larger diameter casing with the auger drive. 
   
   
       19 . A method comprising the steps of:
 rotating a smaller cutting head and smaller auger of a smaller auger assembly to cut an underground hole having a first diameter;   mounting a first section of a swivel on a trailing end of the smaller auger assembly after the underground hole with the first diameter has been cut; and   rotating a second section of the swivel, a larger cutting head and a larger auger of a larger auger assembly relative to the first section to enlarge the underground hole from the first diameter to a second diameter larger than the first diameter.   
   
   
       20 . A method comprising the steps of:
 pushing a swivel forward with a first auger assembly through an underground hole having a first diameter; the swivel comprising first and second sections mounted on one another with relative rotation therebetween; the first auger assembly comprising a first cutting head and a first auger;   during the step of pushing, rotating the second section, first cutting head and first auger relative to the first section to enlarge the underground hole from the first diameter to a second diameter larger than the first diameter; the step of rotating comprising the step of rotating the first auger within a cylindrical casing having a diameter larger than that of the first diameter; and   moving the casing forward into the enlarged underground hole.