Patent ID: 7140806

Claim:
A rod pushing and pulling machine, comprising: at least one hydraulic cylinder having a front end thereof engagable with a reaction surface at an entry opening of a existing pipeline or borehole; a spindle assembly including a frame, a spindle shaft rotatably mounted in the frame, a distal end of the spindle shaft being threaded for engagement with a mating thread of a rod, a drive system for rotating the spindle shaft in threading and unthreading directions, the spindle frame being secured to a rear end of the hydraulic cylinder for pushing or pulling of a rod string engaged to the spindle shaft upon extension or retraction of the hydraulic cylinder, and a support assembly for the spindle shaft, including a set of roller bearings rotatably supporting the spindle shaft, a radial flange on the spindle shaft, and a load flange secured to the spindle frame positioned to engage the radial flange, whereby the radial flange comes into engagement with the load flange during pulling operation to prevent rotation of the spindle shaft during pulling operation, and leaves engagement with the load flange during pushing operation so that the spindle shaft may rotate during pushing operation supported by the roller bearings; and a dual vise assembly including two pairs of separately actuable jaws positioned to grip a rod nearest the spindle shaft and a rod adjacent the rod nearest the spindle shaft.