containing roller assemblies 220 and drive lugs 215 that connect housing 210 to adapter plate 230 adapter plate 230 is connected to stripper assembly 60 via bolts 232 or some other rigid connection roller assemblies 220 engage drillstring 14 and transfer torque from the drillstring through adapter plate 230 to stripper assembly 60 as can be seen in fig9 each roller assembly 220 includes roller 221 upper link 222 and lower link 223 lower links 223 are pivotally connected to housing base plate 214 by individual lower anchor blocks 224 upper links 222 are pivotally connected to follower plate 216 by individual upper anchor blocks 225 biasing member 218 is disposed between follower plate 216 and housing base plate 214 so as to urge the follower plate upward biasing member 218 may be one or more coil springs a hydraulic spring system or any other system for urging follower plate 216 upward the upward movement of follower plate 216 and upper anchor blocks 225 moves rollers 221 inward toward the center of housing 210 and drillstring 14 rollers 221 allow drillstring 14 to move axially while being rotated about its longitudinal axis biasing member 218 applies sufficient force to maintain the contact of rollers 221 on drillstring 14 but also allow increased diameter portions of the drillstring such as tool.