Abstract: A mandrel for insertion into a pipe prevents distortion and buckling while bending the pipe. The mandrel comprises three or more radial support members distributed along a longitudinal extent of the mandrel. A first radial support member is located at a first end of the mandrel. A second radial support member is located at a second end of the mandrel. At least one intermediate radial support member is located between the first and second radial support members. A channel is formed in the at least one intermediate radial support member. A leaf spring extends along the longitudinal extent of the mandrel, and the leaf spring is located within the radial support member channel. The leaf spring has a first and second spring end. A first end bolt attaches the first spring end to the first radial support member. A second end bolt attaches the second spring end to the second radial support member. A compliant member attaches to the leaf spring by a compliant member bolt.

Abstract: An apparatus (20) for counterboring a pipe (25) includes an expander unit (24), a shaft (26) extending from the expander unit, a flywheel (30) rotatably and slidably mounted on the shaft, a frame (34) mounted on the flywheel to be movable in a radial direction, a tool mount (50) and a guide wheel mount (52) formed on the frame, the tool mount traveling with the flywheel into the interior of the pipe during counterboring and the guide wheel mount traveling outside of the pipe during counterboring, the guide wheel mount being connected to the tool mount by guide wheel arm (51) having a radial member (54) that is axially offset to the rear of the tool mount by a distance at least the length of the counterbore to be machined in the pipe, a cutting tool (56) adjustably mounted to the tool mount, a guide wheel (72) rotatably mounted on the guide wheel mount, an inward force applying member (116) and an outward force applying member (122) connected between the flywheel and the frame such that the frame can be moved

Abstract: An apparatus for machining a counterbore in a pipe is provided which comprises an expander unit adapted for being secured against the inside surface of a pipe. A shaft extends from the expander unit coaxial with the pipe and a flywheel is rotatably and slidably mounted on the shaft. A pair of parallel guide structures are mounted on the face of the flywheel, and a frame is slidably mounted on the parallel guide structures such that the frame is linearly movable along the guide structures in a radial direction relative to the shaft. A cutting tool is mounted to the frame and has a distal end that is extendable radially beyond the radially outermost point of the frame. A pair of actuators are attached to the frame and to the flywheel such that the actuators can move the frame along the guide structures and force the cutting tool against the inside surface of the pipe during the counterboring procedure.