Abstract: A machine for reaming heat exchanger tubes of different lengths includes a drive head, or central power unit; a pair of concentric tubes which are removably attached to the drive head and extend rearwardly from it; and a drive shaft having a drive piston on its rearward end which is reciprocably driven within the inner one of the tubes. The length of the tubes and of the drive shaft is selected according to the length of a particular set of heat exchanger tubes that are to be reamed. When a longer or shorter set of tubes are to be reamed, the machine is modified by removing the tubes and the drive shaft from the drive head, and substituting other like members which are correspondingly longer or shorter, as required.

Abstract: A hollow drive shaft, to one end of which a cutterhead is threadedly attached for longitudinal and rotational movement as the shaft is moved through a pipe to be reamed. Passages are provided in the cutterhead for transmission of fluid in the hollow shaft to the exterior of the cutterhead for cooling and removal of drilled or reamed material. The outer periphery of the drive shaft may be provided with a rectangular (square) configuration. The end of the shaft adjacent the cutterhead may receive a cap including a sleeve portion and a flange portion which fits over the end of the drive shaft; the flange may thus be interposed between the drive shaft end face and a shoulder on the cutterhead. The cap fits closely against the periphery of the drive shaft in order to transmit deformation forces from the cutter to the shaft across a wide area of the shaft periphery.

Abstract: A drilling machine especially adapted for reaming tubes includes an elongated hollow drive shaft having a cutterhead attached to its forward end and a drive piston attached to its rearward end. Fluid pressure is applied to the rear end face of the drive piston in order to propel the drive shaft forward, while concurrently supplying fluid which flows out through openings in the cutterhead so as to flush the materials being reamed from a tube that is being cleaned. The machine includes a reversible drive flow for the fluid pressure system. It also includes a separate rotating drive for imparting rotation to the drive shaft.